Angiogenesis is the physiological formation of blood vessels that supplies cells with oxygen and nutrients. It is carried out by endothelial cells, the innermost layer of blood vessels, and depends on pro-angiogenic growth factors, cell-adhesion proteins, and signaling pathways. These pathways regulate different stages of vessel formation, including endothelial-cell proliferation, differentiation, migration, polarity, and survival.

In tumors, dysregulation of these pathways can contribute to uncontrolled angiogenesis, according to the review. The paper examines how VEGF, β-catenin, VE-cadherin, and integrin are associated with Wnt–β-catenin signaling in this process. Wnt–β-catenin signaling is presented as an important pathway for cell proliferation.

The review notes that anomalous activity in this pathway can enhance the expression of pro-angiogenic genes, including VEGF and fibronectin. Within the authors’ model, β-catenin, VE-cadherin, and integrin form an interconnected signaling triad associated with angiogenesis. SFRP4 enters this proposed network because it is a Wnt antagonist with established anti-tumorigenic, anti-angiogenic, and pro-apoptotic roles.

The review’s central proposal is that SFRP4 may act on integrin in a way that disrupts Wnt signaling and thereby inhibits angiogenesis. This extends the proposed connection between SFRP4 and integrin into an explanation for how the Wnt pathway and the broader angiogenic network may interact in tumors. Instead, it reviews angiogenic factors and organizes them into a conceptual model centered on the interplay among SFRP4, integrin, β-catenin, VE-cadherin, and VEGF.

The supplied abstract describes the SFRP4–integrin interaction as a novel proposed role and states that it could disrupt Wnt signaling and inhibit angiogenesis. The available evidence supports the established biological roles summarized by the authors, while the mechanism connecting SFRP4 directly to integrin remains a hypothesis presented by the review. Accordingly, the work provides a framework for understanding possible regulation of the tumor angiogenic loop, but the supplied material does not support claims about human efficacy or clinical application.

The review was published in Medical Oncology in 2026 as volume 43, article 340.

Subject of Research: Proposed SFRP4–integrin regulation of Wnt–β-catenin signaling in tumor angiogenesis

Article Title: The interplay of integrin, VE-cadherin, and β-catenin signaling triad in angiogenesis: regulation by Wnt antagonist, secreted frizzled related protein 4 in the tumor angiogenic loop

Article References: Janaki P, A., Gamit, N., Agarwal, P., Dharmarajan, A., & Warrier, S. (2026). The interplay of integrin, VE-cadherin, and β-catenin signaling triad in angiogenesis: regulation by Wnt antagonist, secreted frizzled related protein 4 in the tumor angiogenic loop. Medical Oncology, 43(11), Article 340. https://doi.org/10.1007/s12032-026-03443-y

Image Credits: AI Generated

DOI: 10.1007/s12032-026-03443-y

Keywords: SFRP4, tumor angiogenesis, integrin, Wnt signaling, β-catenin, VE-cadherin, VEGF, endothelial cells, cancer biology, mechanistic review, interplay, catenin

The investigation was designed around a possible link between Wnt/β-catenin signaling, stem-like cellular characteristics and chemoresistance. The canonical pathway promotes cancer-stem-cell renewal, proliferation and differentiation, while its activation has also been associated with epithelial–mesenchymal transition and metastatic dissemination in earlier colorectal cancer research cited by the authors. Wnt/β-catenin activity may arise through mutations affecting β-catenin or proteins in its destruction complex, as well as through overexpression of Wnt ligands, Frizzled receptors or Dkk-1. Because the pathway has been associated with both tumor progression and therapeutic failure, the researchers examined whether it was active in their established model of long-term 5-FU resistance.

The experimental system consisted of parental HCT-116 colorectal cancer cells and HCT-116 5FUR cells derived through long-term exposure to 5-FU. Previous work with this model had shown that the resistant cells acquired epithelial–mesenchymal transition characteristics together with enhanced migration and invasion. The current study did not determine whether stemness and epithelial–mesenchymal transition are controlled by the same signaling mechanism. Its narrower objective was to measure Wnt/β-catenin activity in the resistant cells, assess selected stemness markers and test whether pharmacological pathway inhibition could make the resistant population more sensitive to 5-FU.

The researchers first used bioinformatic analysis to examine the relationship between two gene signatures in 275 colon cancer samples available through the GEPIA2 platform from The Cancer Genome Atlas. The 5-FU-resistance signature included genes associated with resistance, DNA-damage repair and 5-FU metabolism, while the cancer-stem-cell signature included CD44, PROM1, EPCAM, KLF4, MYC, STAT3, SALL4 and ALDH1A1. Pearson analysis found a positive correlation between the signatures, with R = 0.41 and p < 0.001. This is an association in patient-derived expression data rather than evidence that either signature causes treatment failure, but it provided the clinical-sample context for the subsequent cell experiments.

Laboratory assays showed that the thawed HCT-116 5FUR cells retained their resistant phenotype after recovery from frozen storage. In MTT viability measurements performed 48 hours after exposure to increasing concentrations of 5-FU, the resistant cells tolerated substantially more drug than the parental line. Reverse-transcription quantitative PCR also detected differences in stemness-associated transcripts. ALDH1A1 expression was significantly higher in the resistant cells, whereas POU5F1 showed an upward trend that did not meet the study’s threshold for statistical significance, with p = 0.08. ALDH1A1 was therefore treated as evidence of a stem-like characteristic in this model, not as proof that the entire resistant population consisted of cancer stem cells.

Several measurements indicated stronger canonical Wnt/β-catenin signaling in the 5-FU-resistant cells. Western blotting detected higher levels of both total β-catenin and active, dephosphorylated β-catenin in HCT-116 5FUR cells than in parental cells. Total glycogen synthase kinase 3 beta, or GSK-3β, was lower in the resistant population, while the measured phosphorylated GSK-3β at serine 9 did not differ between the groups. Immunofluorescence imaging likewise showed greater total and active β-catenin staining in the cytoplasm and nuclei of the resistant cells. A TCF/LEF luciferase reporter showed greater β-catenin-dependent transcriptional activity in HCT-116 5FUR cells, and cyclin D1 protein levels were also higher. Taken together, these findings associated the acquisition of 5-FU resistance in this cell line with increased pathway activity.

To test whether that activity contributed to resistance, the investigators used LF3, a 4-thiourea benzenesulfonamide derivative that inhibits the interaction between β-catenin and TCF4. Its negatively charged sulfonamide group binds to Lys435 on β-catenin and competitively prevents the interaction with Asp16 in TCF4, blocking downstream pathway activation. The researchers selected this downstream strategy because colorectal cancer mutations in APC, RNF43 or AXIN2 can generate truncated proteins and constitutive pathway activation, which may limit approaches aimed only at upstream components. In the resistant cells, 60 µM LF3 reduced relative TCF/LEF luciferase activity by approximately sixfold after 24 hours and also reduced cyclin D1 protein levels, confirming both functional pathway inhibition and a downstream molecular effect.

LF3 at the concentration used for pathway blockade did not by itself eliminate the resistant cells. After 48 hours, the maximum tested concentration of 60 µM reduced viability by approximately 30% in both parental and resistant cultures. The LF3 half-maximal inhibitory concentration was 103.5 µM in HCT-116 cells and 135.2 µM in HCT-116 5FUR cells. Combination experiments showed a different effect. The 5-FU IC50 in the resistant cells was 4.8 µM, compared with 0.035 µM in the parental line, documenting the large shift associated with long-term resistance. Adding LF3 lowered the 5-FU IC50 in HCT-116 5FUR cells to 0.138 µM and further reduced viability in the combination condition.

The authors interpret these measurements as evidence that Wnt/β-catenin activity regulates cellular events involved in chemoresistance and that blocking the pathway can impair the resistant phenotype in this model. The stemness and epithelial–mesenchymal transition findings came from separate analyses, so the study did not establish that the two phenotypes are interconnected. The authors propose that cells in intermediate epithelial–mesenchymal states may acquire stem-like characteristics when canonical Wnt signaling is active, but that mechanism was not directly tested here. They also identify long-term 5-FU-resistant cellular models as experimental systems for examining resistance, epithelial–mesenchymal transition and stemness within the same framework.

The scope of the evidence limits how the findings can be interpreted. All experimental results came from the HCT-116 5FUR cell model, while the patient-data analysis established only a correlation between gene signatures. The study did not assess LF3 safety, pharmacokinetics, effects on normal tissues or clinical outcomes, and it did not test combination treatment in animals, organoids or people. The measured result is therefore confined to cultured colorectal cancer cells: LF3 inhibited Wnt/β-catenin transcriptional activity, lowered cyclin D1 and made long-term 5-FU-resistant cells more sensitive to 5-FU in viability assays. The work identifies Wnt/β-catenin inhibition as a candidate combination approach for further preclinical evaluation, but the efficacy and clinical applicability of that approach remain unestablished.

Subject of Research: Wnt/β-catenin inhibition and 5-fluorouracil resistance in a colorectal cancer cell model.

Article Title: Pharmacological inhibition of the canonical Wnt/β-catenin signaling pathway sensitizes 5-fluorouracil-resistant colorectal cancer cells

Article References: Ramos, D. A. A., de Pina, D. F. T., Sousa-Squiavinato, A. C. M., de Araújo, W. M., Rocha, M. R., & Morgado-Diaz, J. A. (2026). Pharmacological inhibition of the canonical Wnt/β-catenin signaling pathway sensitizes 5-fluorouracil-resistant colorectal cancer cells. Molecular Biology Reports, 53(1), Article 1522. https://doi.org/10.1007/s11033-026-12711-z

Image Credits: AI Generated

DOI: 10.1007/s11033-026-12711-z

Keywords: colorectal cancer, 5-fluorouracil resistance, Wnt signaling, β-catenin, LF3 inhibitor, cancer stem cells, HCT-116 cells, chemotherapy sensitization, TCF4, preclinical research, Pharmacological, inhibition

The child was born at 36 weeks of gestation after an uncomplicated pregnancy and vaginal delivery, with no reported perinatal problems. His birth measurements were a head circumference of 32 cm, weight of 3,200 g and length of 47 cm. After the neonatal period, his parents noticed truncal hypotonia, and his motor and language development was delayed. He walked independently at 18 months and produced only a few meaningful words by 5 years of age. At the age of 7, neurological examination showed microcephaly, with a head circumference of 48 cm below the third percentile, truncal hypotonia, peripheral spasticity, hyperactive deep-tendon reflexes and toe-toe walking. His weight and length were each two standard deviations below the expected values for age.

The assessment also identified several dysmorphic facial features, including epicanthal folds, a high-arched palate, a thin upper lip, a long smooth philtrum, an abnormal hairline and small alae nasi. The boy had moderate intellectual disability, required assistance with feeding, had not completed toilet training and could not form a sentence. Autistic behavior, restlessness and sleep disturbance were also present. Ophthalmological examination found strabismus and hypermetropia, for which he wore glasses. These features formed a clinical pattern consistent with CTNNB1-related neurodevelopmental disease: syndromic intellectual disability, global and motor delay, markedly limited speech, microcephaly, spasticity concentrated in the lower limbs, visual abnormalities and behavioral problems.

Initial evaluations for hereditary spastic paraplegia, including a complicated form, and leukodystrophy did not establish a diagnosis. Thyroid function, creatine phosphokinase, liver function, cholesterol and uric acid measurements were within normal limits, and an electrodiagnostic study was normal. Brain magnetic resonance imaging performed at 5 years of age was also reported as normal. The absence of abnormalities on metabolic testing and neuroimaging did not explain the combination of developmental impairment, hypotonia and spasticity, prompting the investigators to proceed with genetic analysis. The report emphasizes that CTNNB1-associated disease can remain in the differential diagnosis even when the perinatal history and initial neurological investigations are unremarkable.

For the molecular investigation, the researchers collected blood samples from the child and his parents and isolated genomic DNA using a salting-out method. Whole-exome sequencing was performed with the Agilent SureSelect Human All Exon V7 Target Enrichment kit, followed by sequencing on an Illumina NovaSeq 6000 platform to generate 150-base-pair paired-end reads. Reads were aligned to the GRCh37/hg19 reference genome with the Burrows-Wheeler Aligner, converted into sorted BAM files with SAMtools and assessed for raw-data quality with FastQC. The analysis set a mean depth-of-coverage threshold of at least 30-fold, and regions with insufficient coverage were addressed through supplementary sequencing. The resulting analysis identified a heterozygous A-to-C substitution at coding position 2215 in CTNNB1 as the most plausible pathogenic candidate.

Integrative visualization of the whole-exome data showed nearly balanced allelic reads at the variant site, with 58 adenine reads representing 51% of the sequence and 55 cytosine reads representing 49%, each with base-call quality above Q40. The finding was then validated using conventional Sanger sequencing on an ABI 3500 Genetic Analyzer. A 229-base-pair amplicon was amplified with primers 5′-TGGATGCCCTAACCTCAGTGT-3′ and 5′-CAGATCTGGCAGCCCATCAA-3′ at an annealing temperature of 60 °C. The proband’s chromatogram confirmed the heterozygous A>C change, while both parents showed wild-type sequences. The family segregation analysis therefore supported a de novo origin for the variant rather than inheritance from either parent.

At the DNA level, the change is designated NM_001904.4:c.2215A>C and converts the coding sequence ATG to CTG, producing the amino-acid substitution p.Met739Leu. Methionine and leucine are both nonpolar amino acids, but the substitution occurs near the C-terminal region of the coding sequence and maps to the armadillo-repeat domain of beta-catenin, the protein encoded by CTNNB1. The investigators applied ACMG guidelines and assigned a likely pathogenic classification using several pieces of evidence: PM2 for an extremely low or absent population frequency, PP4 for a highly characteristic phenotype, PM6 for the de novo occurrence in an affected individual and PP2 for a missense change in a gene with a low rate of benign missense variation and a known disease mechanism. The reported allele frequency in gnomAD was 0%, with no homozygous individuals observed.

CTNNB1 encodes beta-catenin, a protein involved in several processes relevant to neural development. It is central to the Wnt/beta-catenin signaling pathway and contributes to the formation of adherens junctions, cell adhesion, neural stem-cell proliferation, neurogenesis, neuronal survival and synaptic connections. The armadillo-repeat region containing the new variant is therefore of particular interest because beta-catenin coordinates mechanisms that influence neuronal architecture and synaptic function. Most previously established CTNNB1 disease variants associated with NEDSDV are loss-of-function changes, whereas pathogenic or likely pathogenic missense variants have been reported less often. The c.2215A>C change was not found in ClinVar or other publicly available disease databases, according to the report, making it a previously unreported candidate rather than an established disease-causing variant with extensive clinical precedent.

The case also fits the broader history and clinical distribution of CTNNB1-related neurodevelopmental disorder. The first cases were linked to de novo CTNNB1 variants through exome sequencing in 2012, and a later genomic and phenotypic study described 404 patients with CTNNB1-related neurodevelopmental disorders, describing a largely consistent set of neurological features. Subsequent reports have documented the disorder in Chinese, Iranian and Korean populations, supporting its occurrence across geographic and ethnic groups. Retinopathy and vitreoretinopathy have also been recognized in some affected individuals, while a previously described missense variant, c.1723G>A or p.Gly575Arg, was associated with significant vitreoretinopathy. The 7-year-old in the present report had strabismus and hypermetropia but no reported retinal disorder.

Overall, the report provides clinical and molecular evidence for a de novo CTNNB1 missense variant in a child whose presentation included developmental delay, microcephaly, truncal hypotonia, spasticity, intellectual disability, restricted speech, autistic behavior, sleep disturbance and visual defects. It illustrates a sequential diagnostic approach in which whole-exome sequencing identified the candidate change and Sanger sequencing established its presence in the child and its absence in both parents. The findings expand the reported allelic diversity of CTNNB1-related neurodevelopmental disorders and provide an additional case for evaluating the boundary between loss-of-function and missense mechanisms. The classification remains provisional in a strict mechanistic sense: no functional assays were reported to demonstrate how p.Met739Leu alters beta-catenin structure or Wnt signaling, and a single-patient case cannot establish prevalence, natural history or the full consequences of the variant. The boy was receiving outpatient physical, occupational and speech therapy, with regular multidisciplinary follow-up, and the report identifies no established disease-specific treatment.

Subject of Research: Clinical and molecular characterization of a de novo CTNNB1 p.Met739Leu variant in a child with neurodevelopmental disorder with spastic diplegia and visual defects.

Article Title: A Novel De Novo Heterozygous Missense Variant in CTNNB1 (c.2215A>C, p.Met739Leu) Underlying Neurodevelopmental Disorder With Spastic Diplegia and Visual Defects (NEDSDV): A Case Report

Article References: Ibrahim, O. J., Rajabi, A., Bonyadi, M., & Barzegar, M. (2026). A Novel De Novo Heterozygous Missense Variant in CTNNB1 (c. 2215A >C, p. Met739Leu ) Underlying Neurodevelopmental Disorder With Spastic Diplegia and Visual Defects ( NEDSDV ): A Case Report. Clinical Case Reports, 14(10), Article e73743. https://doi.org/10.1002/ccr3.73743

Image Credits: AI Generated

DOI: 10.1002/ccr3.73743

Keywords: CTNNB1, NEDSDV, missense variant, spastic diplegia, visual defects, whole-exome sequencing, Sanger sequencing, beta-catenin, Wnt signaling, case report, Novel, Novo

Oculodentodigital dysplasia, or ODDD, is an ultra-rare autosomal dominant disorder caused by germline variants in GJA1. Patients typically show a pleiotropic constellation of features affecting the eyes, teeth, digits, and sometimes the central nervous system, with severity varying dramatically even within the same family. Connexin 43 is the most ubiquitously expressed connexin in the human body, forming gap junction channels that allow direct cytoplasmic exchange between adjacent cells. But the protein’s long C-terminal tail also does channel-independent work, physically associating with signaling partners such as β-catenin and various kinases. It is this second, scaffolding role that the new research places at the center of the disease mechanism.

The team, led by researchers at Peking Union Medical College Hospital and Children’s Hospital of Soochow University, recruited two families with classic ODDD presentations. Proband 1, a young girl, displayed short palpebral fissures, hypoplastic alae nasi, sparse hair, bilateral syndactyly of the fourth and fifth fingers, and dental anomalies including microdontia and enamel hypoplasia. Her affected younger brother carried the same craniofacial and hand phenotype, while their mother showed only mild bilateral brachydactyly of the fifth fingers—a striking example of intra-familial variability. Proband 2 presented similar features along with syndactyly of the toes, and whole-genome sequencing revealed his variant arose de novo, absent from both clinically healthy parents. Sanger sequencing confirmed heterozygous missense variants, c.253G>C in Family 1 and c.605G>A in Family 2, both segregating perfectly with disease status.

What makes the study unusual is its reliance on primary patient-derived cells rather than engineered model systems. The researchers cultured skin fibroblasts from both patients and mesenchymal stromal cells, or MSCs, harvested from discarded surgical bone and skin tissue collected during syndactyly release and corrective osteotomy procedures. Controls came from age- and sex-matched pediatric patients undergoing hand trauma surgery at the same anatomical site, with whole-genome sequencing used to exclude any pathogenic variants in known disease genes. Flow cytometry confirmed the MSC identity, with cells positive for CD90, CD105, and CD73 and negative for CD45, meeting the International Society for Cellular Therapy minimal criteria.

RNA sequencing on patient fibroblasts and MSCs revealed a transcriptional landscape split cleanly in two. Downregulated gene sets were dominated by Wnt signaling, extracellular matrix–receptor interaction, osteoblast differentiation, DNA replication, and cell cycle regulation. Upregulated sets lit up with inflammatory response genes, cytokine-mediated signaling, JAK-STAT signaling, tumor necrosis factor response, and ECM structural constituents. The team then validated these patterns at the protein level using RT-qPCR, Western blotting, immunofluorescence, and ELISA. In both fibroblasts and MSCs, mRNA levels of canonical Wnt targets—AXIN2, CCND1, PCNA, and c-MYC—fell sharply. Protein levels of Cx43, β-catenin, and IκBα dropped in parallel, while the ratio of phosphorylated p65 to total p65 rose, a signature of NF-κB pathway activation.

The inflammatory profile that emerged is the study’s most surprising finding. Interleukin-6 expression and secretion surged in patient cells, yet CXCL8—better known as IL-8—was paradoxically and significantly reduced, despite NF-κB being switched on. Interferon-stimulated genes MX1 and IFIT1 were simultaneously elevated. The researchers traced this uncoupling to c-MYC, the Wnt-dependent transcription factor whose loss appears to lift normal repression on MMP3 while simultaneously starving CXCL8 of a required activator. MMP3, or stromelysin-1, is a matrix metalloproteinase that degrades components of the extracellular matrix, and its abnormal upregulation points to excessive ECM remodeling—a process that could plausibly underlie the tissue fusion seen in syndactyly, though the authors caution that this connection remains speculative and requires in vivo validation.

Functional assays confirmed the molecular story has real cellular consequences. Transwell migration assays showed patient fibroblasts and MSCs crossed basement membranes at markedly reduced rates, while EdU incorporation revealed suppressed proliferation. These defects align with the coordinated downregulation of CCND1, PCNA, and c-MYC, key regulators of the G1/S cell cycle transition, suggesting GJA1 deficiency stalls cells before they enter DNA synthesis. Differentiation assays added another layer: patient MSCs showed compromised osteogenic capacity, with reduced alkaline phosphatase activity and diminished Alizarin Red S mineralization, alongside aberrantly enhanced adipogenic potential measured by Oil Red O staining. This lineage shift mirrors the classical biology of Wnt signaling, which normally maintains MSC stemness, promotes bone formation, and suppresses fat cell differentiation—offering a cellular explanation for the bone hypoplasia seen in ODDD patients.

To establish causality rather than mere correlation, the team ran bidirectional genetic interventions. Knocking down GJA1 with siRNA in normal control cells, reducing expression to roughly the level seen in patient cells, faithfully reproduced the entire patient phenotype: Wnt suppression, the IL-6-high/CXCL8-low inflammatory bias, elevated MMP3, impaired migration, and skewed differentiation. Conversely, overexpressing wild-type connexin 43 in patient cells substantially reversed these defects, restoring IκBα levels, reducing p65 phosphorylation, suppressing MMP3, and rescuing migration. A second round of experiments isolated c-MYC’s role directly: silencing c-MYC in normal MSCs reproduced the CXCL8 collapse and MMP3 surge, while overexpressing c-MYC in patient MSCs rescued both, establishing c-MYC as a necessary and sufficient regulator of these two genes downstream of the GJA1/Wnt axis.

Pharmacological experiments then mapped the hierarchy of the pathway. Treating patient cells with CHIR99021, a selective GSK-3β inhibitor that activates canonical Wnt signaling, restored c-MYC expression, corrected the CXCL8 deficit, suppressed MMP3, reduced IL-6 secretion, and improved both migration and osteogenic differentiation. In contrast, a neutralizing antibody against IL-6 acted only on downstream readouts: it dampened the interferon response but failed to restore c-MYC, could not rescue CXCL8, and left MMP3 overexpression untouched. The combination of both agents produced the strongest overall rescue, simultaneously targeting the core upstream defect and the downstream inflammatory overactivation. The comparison makes a clear translational argument: blocking a single cytokine treats symptoms, but reactivating the Wnt/c-MYC axis addresses the disease’s root signaling failure.

The authors are candid about the study’s limits. Fibroblasts came from only two patients and MSCs from one, so transcriptomic findings are explicitly framed as exploratory, and technical replicates from a single donor cannot substitute for independent biological replicates. The researchers also could not perform promoter-reporter or chromatin immunoprecipitation experiments to demonstrate direct c-MYC binding at the CXCL8 or MMP3 promoters, again because of the scarcity of pediatric patient cells. Connexin 43’s broad expression in heart, brain, and skin means long-term neurological and cardiac follow-up of the two families is warranted, even though neither child currently shows overt deficits in those systems. Still, the work delivers a coherent new pathogenic framework for ODDD—one in which a broken gap junction protein silently rewires Wnt, NF-κB, and matrix remodeling all at once—and it nominates Wnt activation, rather than isolated cytokine blockade, as the therapeutic strategy most worth pursuing in this rare and poorly understood disorder.

Subject of Research: Molecular mechanisms of GJA1-related oculodentodigital dysplasia in patient-derived fibroblasts and mesenchymal stromal cells

Article Title: GJA1 dysfunction suppresses Wnt/c-MYC signaling and promotes inflammatory imbalance and MMP3-associated ECM remodeling in fibroblasts and mesenchymal stromal cells from patients with ODDD

Article References: Tao, S., Zhao, B., Wang, X., Shen, X., & Zhao, X. (2026). GJA1 dysfunction suppresses Wnt/c-MYC signaling and promotes inflammatory imbalance and MMP3-associated ECM remodeling in fibroblasts and mesenchymal stromal cells from patients with ODDD. Frontiers in Cell and Developmental Biology, 14, Article 1959966. https://doi.org/10.3389/fcell.2026.1959966

Image Credits: AI Generated

DOI: 10.3389/fcell.2026.1959966

Keywords: oculodentodigital dysplasia, GJA1, connexin 43, Wnt signaling, c-MYC, NF-κB, MMP3, mesenchymal stromal cells, fibroblasts, rare disease, osteogenic differentiation, CHIR99021

The investigation began with a pragmatic problem. Earlier work had shown that the chloroform fraction of G. thalictroides roots was strongly cytotoxic against cancer cell lines, and four active compounds had already been isolated, including two beta-carboline alkaloids and two cyclopeptides. But several minor metabolites visible in chromatographic profiles could not be captured in sufficient quantity for full structural elucidation. To close these gaps, the researchers re-extracted four kilograms of dried roots with ethanol, partitioned the resulting extract into hexane, chloroform, and ethyl acetate fractions, and prepared a traditional water decoction in parallel, mirroring exactly how local practitioners steep half a teaspoon of dried root in boiling water and drink it twice a day.

Before any purification began, the team mapped the plant’s entire metabolome using ultra-high-performance liquid chromatography coupled with high-resolution tandem mass spectrometry. The resulting data were assembled into a molecular network, a computational map in which each node represents a detected compound and edges connect molecules with similar fragmentation patterns. The network contained 2,066 nodes linked by 3,075 edges, and through in silico database searching combined with a taxonomically informed scoring filter, the team tentatively annotated 284 compounds, refining thirteen of them to metabolites previously reported in the Rubiaceae family. Distinct clusters emerged corresponding to indole alkaloids characteristic of the plant family and to the cyclopeptides already known from this species.

Armed with this map, the researchers then chased the actual molecules. Medium-pressure liquid chromatography with ultraviolet detection generated eighty-two fractions, many of which were further purified by semi-preparative HPLC, ultimately yielding twenty-six fully characterized compounds. The haul included phenolic glycosides, iridoids, coumarins, lignans, anthraquinones, and two important families of nitrogen-containing metabolites: Rubiaceae-type cyclopeptides of the bouvardin series and beta-carboline alkaloids. Three of the isolated compounds proved to be previously unknown natural products, and one anthraquinone, 1-methoxy-2,7-dihydroxyanthraquinone, was reported as a natural-source isolate for the first time.

The new cyclopeptides were the first major prize. Compound 18, named 5-beta-hydroxy-RA-XII, turned out to be a bouvardin-type cyclic hexapeptide bearing an appended glucose unit attached to the tyrosine-6 residue, a feature confirmed by nuclear magnetic resonance correlations from the sugar’s anomeric proton to the aromatic carbon of the tyrosine ring and by high-resolution mass spectrometry. Compound 19, dubbed 5-beta-hydroxy-RA-I, carries an additional oxygen relative to bouvardin: careful inspection of its spectra revealed that a methyl doublet belonging to the alanine-2 residue had vanished, replaced by an oxymethylene signal, indicating that an alanine had been converted to a serine. Both nomenclatures follow the RA-series convention established decades ago for related antitumor hexapeptides from Rubia species.

The most consequential chemical revision involved the beta-carboline alkaloids 24 and 25, which had been described in earlier studies of the same species. The original assignments posited two independent tertiary alcohols in the aliphatic side chain and treated key mass spectrometric ions as water-loss adducts. The new analysis flipped that interpretation. Instead, the team proposed that the two tertiary alcohols cyclize to form an internal ether, creating an extra five-membered ring, so that the observed ions correspond directly to protonated molecules. Carbon-13 chemical shift comparisons with structurally related ether-bridged compounds in the literature supported this reading, and the consistency of the proposed structures with all one- and two-dimensional NMR data was verified using the CT web application, which performs complete quantum mechanical spectral analysis, iteratively optimizing chemical shifts and coupling constants against calculated proton spectra.

Establishing the three-dimensional architecture demanded additional computational muscle. Relative configurations were locked down through nuclear Overhauser effect correlations, while absolute configurations were assigned by comparing experimental electronic circular dichroism spectra with spectra calculated for both candidate stereoisomers using time-dependent density functional theory. For the revised alkaloid 24, the experimental trace matched the 14R,15R,18S isomer. For the genuinely new alkaloid 23, which features an intramolecular ether bridge and a hydroxylated methine in a compact tetracyclic framework, the calculations pointed unambiguously to the 14S,15S,18R,19R configuration. Every structural claim in the paper therefore rests on converging lines of spectroscopic and computational evidence rather than a single technique.

With pure compounds in hand, the biological evaluation delivered striking results. Testing against BT-20 triple-negative breast cancer cells, an aggressive subtype lacking the three most common therapeutic targets, the bouvardin family dominated the potency rankings. Bouvardin itself and 6-O-methylbouvardin inhibited cell survival with IC50 values of roughly 0.25 micromolar, while 5-beta-hydroxy-RA-III followed at 2.7 micromolar. Structure-activity patterns emerged clearly: adding a hydroxyl group at the alanine-2 position reduced potency several-fold, and the bulky, highly polar glucose of compound 18 attenuated activity tenfold, plausibly by limiting cellular uptake. Anthraquinones showed moderate activity between 23 and 110 micromolar, and the beta-carbolines ranged from 65 to 193 micromolar, weaker but still biologically meaningful. Mechanistically, bouvardins are known inhibitors of protein biosynthesis, while anthraquinones can generate reactive oxygen species and form the scaffold of several approved anticancer drugs.

The beta-carbolines told a more intriguing mechanistic story. Because this scaffold had previously been shown to suppress Wnt signaling, a central oncogenic pathway implicated in tumor progression, therapy resistance, cancer stem cell maintenance, and epithelial-mesenchymal transition, the researchers ran a TopFlash reporter assay measuring Wnt3a-driven transcription in the same BT-20 cells. Compound 24 emerged as a selective Wnt pathway inhibitor with an IC50 near 40 micromolar, while its close analog 25, lacking the C-19 hydroxyl group, showed no specific Wnt inhibition at all. Compound 23 was entirely inactive, likely because its indole nitrogen is sequestered in an intramolecular cyclization and cannot engage biological targets. Both active and inactive derivatives were ten to twenty times less potent than the best Wnt-targeting beta-carbolines reported previously, so the authors are candid that these particular molecules are not optimal scaffolds, but the sharp activity difference between 24 and 25 provides a valuable structural clue about which molecular features matter for pathway inhibition.

Perhaps the most provocative conclusion concerns the plant as a whole. The cytotoxic bouvardins and the Wnt-selective beta-carboline coexist in the same chloroform fraction, and the authors argue that this combination may function as a multi-component anticancer system, with Wnt inhibition potentially sensitizing cancer cells to cytotoxic stress and simultaneous effects on tumor progression, recurrence, and apoptosis. Notably, the molecular network revealed that the cyclopeptides and beta-carbolines appear absent or only trace in the traditional water decoction, raising questions about which constituents actually reach patients drinking the remedy. The authors frame their findings as a foundation for pharmacological investigation, in vivo studies, and ultimately drug development, and the discovery of three new molecules, the correction of two flawed structures, and the demonstration of pathway-specific activity together make G. thalictroides one of the more compelling underexplored sources of anticancer natural products to emerge from Brazilian ethnobotany in recent years.

Subject of Research: Phytochemistry and anticancer bioactivity of Galianthe thalictroides metabolites

Article Title: Comprehensive phytochemical study of Galianthe thalictroides: isolation of three new compounds, structural revision of β-carbolines, and evaluation of cytotoxic and anti-wnt activities

Article References: Figueiredo, P. D. O., Kirchhoffer, O. A., Marcourt, L., Quiros-Guerrero, L., Koval, A., Kato Junior, W. H., Yoshida, N. C., Garcez, F. R., Garcez, W. S., Katanaev, V. L., Wolfender, J.-L., & Queiroz, E. F. (2026). Comprehensive phytochemical study of Galianthe thalictroides: isolation of three new compounds, structural revision of β-carbolines, and evaluation of cytotoxic and anti-wnt activities. Frontiers in Natural Products, 5, Article 1840056. https://doi.org/10.3389/fntpr.2026.1840056

Image Credits: AI Generated

DOI: 10.3389/fntpr.2026.1840056

Keywords: Galianthe thalictroides, natural products, cyclopeptides, beta-carboline alkaloids, Wnt signaling, cytotoxicity, triple-negative breast cancer, molecular networking, NMR, electronic circular dichroism, bouvardin, ethnopharmacology

The research team sequenced the transcriptome, the complete set of RNA messages active in the embryo, across eight distinct developmental stages, labeled Groups A through H, spanning the journey from freshly fertilized egg to pre-hatching embryo. By pairing these molecular snapshots with careful morphological observation, the researchers could align what was happening inside cells with what was visibly happening to the embryo itself. Time-series clustering of the resulting data identified 13 significant expression profiles, several of which formed large clusters with clearly distinct temporal patterns, revealing that embryonic development in the prawn proceeds through coordinated waves of gene activity rather than a smooth, continuous ramp-up.

The single most dramatic moment in the entire dataset came at the very beginning. Comparing the earliest stage, Group A, with the next stage, Group B, produced the largest transcriptomic shift of the whole study: 17,710 genes were downregulated and 12,640 genes were upregulated between these two points. That scale of change, affecting tens of thousands of transcripts, points to extensive transcriptional reprogramming during early embryogenesis. The authors suggest this pattern is potentially consistent with the maternal-to-zygotic transition, a fundamental event in animal development in which the embryo discards the RNA instructions its mother deposited in the egg and switches on its own genome. Importantly, the researchers are careful to note that their data do not directly demonstrate maternal RNA clearance or zygotic genome activation; the massive shift is consistent with that transition but does not prove it on its own.

The maternal-to-zygotic transition is one of the great conserved milestones of animal biology. In fruit flies, zebrafish, frogs and mice, embryos begin life dependent on maternal messenger RNAs and proteins stockpiled in the egg, and only later activate their own transcriptional programs. Pinpointing a possible signature of this handover in a crustacean extends the comparative picture of how this event is orchestrated across the animal tree, and it gives prawn biologists a molecular landmark for the earliest hours of development that was previously missing.

When the team ran pathway enrichment analysis on the genes differentially expressed between stages A and B, two broad themes emerged. The first was metabolism: genes associated with fat digestion and absorption and with fatty acid biosynthesis were significantly overrepresented, hinting that the early embryo is reorganizing how it mobilizes energy and builds membranes from the lipid reserves packed into the yolk. The second theme was developmental signaling: conserved pathways that sculpt embryos across the animal kingdom, including the Wnt, Hippo and TGF-beta signaling pathways, were prominently enriched. These are the same ancient communication networks that pattern body axes, control cell proliferation and coordinate tissue growth in organisms from insects to humans, and their early activation in the prawn embryo underscores how deeply conserved the logic of animal development really is.

The next transition the team examined, from stage B to stage C, corresponding to the move from cleavage to blastula, told a different molecular story. Here the enriched pathways included those related to pluripotency, the capacity of cells to become any tissue in the body, alongside melanogenesis and tyrosine metabolism. That combination is intriguing because melanin production is central to pigment formation, and in the developing prawn eye pigment plays a structural and functional role. The authors suggest that eye-related transcriptional programs may begin to emerge as early as the blastula stage, long before any recognizable eye structure is visible, a reminder that the genetic blueprint for an organ can be switched on well before the organ itself takes shape.

Perhaps the most vivid transition in the dataset is the passage from stage F to stage G, the interval during which the embryo goes from possessing a primitive heart tube to exhibiting a regular, strong heartbeat. Genes involved in cardiac muscle contraction were enriched in this window, together with adrenergic signaling, the biochemical system that allows the nervous system to modulate heart rate, and neuroactive ligand-receptor interaction pathways. In parallel, sensory-related gene ontology terms including phototransduction and visual perception also rose to prominence. Taken together, the data capture a moment when the embryo is simultaneously wiring its cardiovascular system, its nervous system and its sensory apparatus, and the transcriptome reflects that triple build-out with striking clarity.

To make sure their sequencing results were not an artifact of the platform, the researchers validated their findings using quantitative reverse-transcription PCR, or qRT-PCR, on six selected differentially expressed genes. The expression trends measured by this independent method matched the RNA sequencing results for these genes, lending confidence that the stage-specific patterns reported in the study are robust rather than technical noise. This kind of cross-validation is standard good practice in transcriptomics, and its inclusion strengthens the study’s value as a reference resource.

The practical implications reach beyond developmental biology. Because M. rosenbergii aquaculture depends on reliable hatchery production, understanding which genes and pathways govern each embryonic stage could eventually inform hatchery management, helping farmers optimize incubation conditions or identify developmental problems earlier. The stage-associated expression patterns and enriched pathways documented here also provide raw material for selective breeding programs, since traits tied to egg quality, hatching success and early survival all have molecular underpinnings that this dataset begins to expose. The authors frame their work as a transcriptomic resource for the community, and that framing is apt: a well-annotated time series of embryonic gene expression is exactly the kind of foundation on which functional studies, marker development and comparative genomics can be built.

Scientifically, the study broadens the molecular description of crustacean embryogenesis, a field that has lagged behind work on insect and vertebrate models. By documenting when metabolic programs, conserved signaling cascades, pluripotency-associated pathways, cardiac genes and sensory modules come online, the researchers have turned a commercially vital but molecularly opaque species into a system where development can be interrogated gene by gene. The careful caveat the authors attach to the maternal-to-zygotic transition interpretation is also worth noting: it models how developmental transcriptomics should be reported, distinguishing between patterns that are consistent with a mechanism and direct evidence for it. Future work, perhaps combining RNA measurements with methods that directly track maternal transcript decay and zygotic transcription, could convert that consistency into proof. For now, the prawn embryo has given up a remarkable share of its secrets, and the timeline assembled by Han and colleagues will serve as the reference map for everyone who follows.

Subject of Research: Transcriptomic profiling of embryonic development in the giant river prawn Macrobrachium rosenbergii

Article Title: Morphological and transcriptomic analyses reveal the embryonic development of Macrobrachium rosenbergii

Article References: Han, P., Sun, Q., Fan, Y., Zhang, H., Ren, D., Chen, J., & Wang, X. (2026). Morphological and transcriptomic analyses reveal the embryonic development of Macrobrachium rosenbergii. BMC Genomics. https://doi.org/10.1186/s12864-026-13434-y

Image Credits: AI Generated

DOI: 10.1186/s12864-026-13434-y

Keywords: Macrobrachium rosenbergii, embryogenesis, transcriptome, maternal-to-zygotic transition, crustacean development, Wnt signaling, Hippo signaling, TGF-beta signaling, cardiac development, phototransduction, aquaculture, qRT-PCR

To appreciate why this matters, it helps to understand how the canonical Wnt pathway operates. In the absence of a Wnt ligand, β-catenin — a protein that doubles as a structural component of cell adhesion junctions — is continuously phosphorylated by a destruction complex centered on the enzyme glycogen synthase kinase-3β, or GSK-3β. Phosphorylation tags β-catenin for ubiquitination and proteasomal degradation, keeping its levels vanishingly low. When Wnt ligands bind their Frizzled and LRP5/6 co-receptors at the cell surface, this destruction complex is inhibited, β-catenin accumulates, translocates into the nucleus, and partners with TCF/LEF transcription factors to activate target genes. In the off state, TCF/LEF proteins actually act as repressors, bound to co-repressors such as Groucho/TLE. When β-catenin arrives, the repressor complex is converted into an activator complex. This elegant molecular switch governs cell fate decisions, proliferation, and differentiation during embryonic development, and it remains active in the adult brain, where it influences synaptic plasticity, neuroinflammation, and central nervous system homeostasis.

The review’s central claim is that accumulating evidence implicates aberrant TCF/LEF signaling in the pathophysiology of major neuropsychiatric conditions. This is not a single-gene, single-disease story. Instead, the authors argue that dysregulation of a shared signaling axis converges on multiple disease phenotypes. The Wnt/β-catenin pathway has previously been implicated in mood disorders through studies of GSK-3β, which is the direct molecular target of lithium — the oldest and still widely used treatment for bipolar disorder. Lithium’s therapeutic effect has long been known to involve inhibition of GSK-3β, thereby stabilizing β-catenin and potentiating TCF/LEF-mediated transcription. The new review places the TCF/LEF transcription factors themselves, rather than merely the upstream kinases, at the center of this therapeutic logic, framing them as the nodes where upstream signals from multiple sources are integrated into coherent transcriptional programs.

A substantial portion of the review is devoted to mapping the downstream target gene networks that TCF/LEF factors control in the brain. These networks include genes encoding neurotrophins — the growth factors that support neuronal survival and synaptic strengthening — as well as neurotransmitter receptors, which mediate chemical signaling between neurons and are the targets of most existing psychiatric drugs. The networks also encompass ion channels, which set the electrical excitability of neurons, myelination-related genes, which govern the insulation of axons and the speed of signal conduction, and metabolic regulators, which couple neuronal activity to energy metabolism. The authors argue that dysregulation of these gene networks may contribute to disease-related phenotypes ranging from impaired synaptic plasticity in depression to disrupted neurodevelopment in autism spectrum disorder and schizophrenia. In other words, a single transcription factor family sits upstream of an astonishingly broad set of cellular functions that, when perturbed, produce the heterogeneous symptoms clinicians see in the clinic.

Particular attention is given to TCF7L2, and for good reason. Among the four family members, TCF7L2 stands out for its convergent roles in neural development, synaptic function, and metabolic integration. It is also genetically associated with multiple neuropsychiatric conditions. TCF7L2 is, notably, one of the most strongly replicated genetic risk loci for type 2 diabetes, and epidemiological and genetic studies have repeatedly observed overlapping susceptibility between metabolic disease and psychiatric conditions such as depression. The review suggests that TCF7L2 may be a molecular bridge explaining part of this comorbidity: a single transcription factor that simultaneously regulates neural circuit formation, synapse maintenance, and systemic glucose and lipid metabolism. If correct, this reframes psychiatric disorders not as purely brain-limited conditions but as conditions whose pathology is entangled with whole-body metabolic state — a perspective that aligns with the growing literature on insulin resistance and inflammation in depression.

The spatiotemporal dimension of TCF/LEF expression adds another layer of complexity that the review carefully addresses. The four family members are not interchangeable. They are expressed in different brain regions, in different cell types, and at different developmental time points, and they perform partially distinct biochemical roles. TCF1 and LEF1 are generally considered canonical β-catenin-dependent activators, whereas TCF7L1 frequently functions as a constitutive repressor that can sequester β-catenin or dampen transcription even in the presence of signaling. TCF7L2 can act in both modes depending on context. This division of labor means that a therapeutic strategy aimed simply at boosting or blocking Wnt signaling globally would produce different — and potentially opposing — effects in different cell populations. Precision, the authors argue, will require understanding which TCF/LEF member is dysregulated, in which cells, and at which stage of disease.

On the therapeutic front, the review evaluates emerging strategies targeting the Wnt/β-catenin/TCF axis. The most clinically mature approach involves GSK-3β inhibitors, which indirectly enhance β-catenin signaling by preventing its degradation. Lithium is the prototype, but more selective GSK-3β inhibitors have been developed and tested in preclinical models of mood disorders and neurodegeneration. The authors also discuss repurposed drugs — existing medications whose effects on the Wnt pathway were discovered after their original approval — as a faster route to clinical translation, since their safety profiles in humans are already established. Beyond pharmacological intervention, the review highlights the potential of TCF/LEF-related molecular signatures as biomarkers for patient stratification. In a field where diagnosis remains entirely syndromic and treatment selection is largely trial and error, the prospect of using pathway-based biomarkers to identify which patients are likely to respond to Wnt-targeting interventions represents a concrete step toward precision psychiatry.

The authors are careful to frame their conclusions as a synthesis rather than a finished clinical roadmap, and they devote considerable space to key knowledge gaps and future directions. Among the challenges inherent in this area is the pathway’s pleiotropy: because Wnt/β-catenin signaling is essential in the intestine, bone, and hematopoietic system, systemic manipulation carries real risks, and the oncology literature has long struggled with toxicity in Wnt-targeting drug development. Achieving brain-selective modulation, whether through biased ligands, cell-type-specific delivery, or targeting protein-protein interactions between β-catenin and individual TCF/LEF members, remains an unsolved engineering problem. The review also underscores that much of the evidence linking TCF/LEF signaling to psychiatric phenotypes comes from preclinical models and genetic association studies, and that translating these findings into validated human therapeutics will require rigorous testing.

Nevertheless, the conceptual contribution of the review is significant. By elevating the TCF/LEF transcription factors from obscure developmental regulators to candidate therapeutic nodes and biomarkers, it offers psychiatry a unifying molecular framework that connects neurodevelopment, synaptic function, neuroinflammation, and metabolism under a single signaling umbrella. The work was supported by the Beijing-Tianjin-Hebei Basic Research Cooperation Special Project, the National Natural Science Foundation of China, and Hebei Provincial research funds, and it is published under open access terms, making the full synthesis freely available to researchers worldwide. Whether TCF7L2 and its siblings will ultimately yield new medications for depression, schizophrenia, or Alzheimer’s disease remains an open question, but the review makes a compelling case that the answers, wherever they lie, will be found at the point where Wnt signals meet the genome.

Subject of Research: TCF/LEF transcription factors as therapeutic targets in neuropsychiatric disorders via Wnt/β-catenin signaling

Article Title: Therapeutic targeting of TCF/LEF transcription factors in neuropsychiatric disorders via Wnt/β-catenin signaling

Article References: Li, X., Sang, Y., Yu, Q., Liu, X., Li, Y., Wang, Q., Liu, D., Gao, Y., Shi, H., & Shi, Y. (2026). Therapeutic targeting of TCF/LEF transcription factors in neuropsychiatric disorders via Wnt/β-catenin signaling. Translational Psychiatry. https://doi.org/10.1038/s41398-026-04509-1

Image Credits: AI Generated

DOI: 10.1038/s41398-026-04509-1

Keywords: TCF/LEF, Wnt signaling, beta-catenin, TCF7L2, GSK-3beta, neuropsychiatric disorders, transcription factors, synaptic plasticity, precision psychiatry, bipolar disorder, schizophrenia, Alzheimer's disease

The research team used single-cell RNA sequencing to profile Müllerian ducts from chicken embryos at the stage when the ducts have just formed and are beginning to differentiate. The analysis revealed a degree of cellular complexity that previous bulk approaches had obscured. Rather than appearing as simple tubes with a uniform lining and a uniform surrounding layer, the ducts resolved into distinct transcriptional populations corresponding to their two principal compartments: the Müllerian duct epithelium, the inner lining that will give rise to the functional tissues of the reproductive tract, and the Müllerian duct mesenchyme, the surrounding connective tissue that directs and supports epithelial development. Each compartment carries a clear molecular signature that the authors could catalog in detail.

The epithelial compartment, termed the Müllerian duct epithelium, expresses a recognizable suite of genes that includes the transcription factors PAX2 and LHX1, both long known as central regulators of duct formation, together with members of the WNT7 family, the stem-cell-associated receptor LGR5, the paracrine signaling factors PDGFA and PDGFD, and the cadherins CDH1 and CDH2, which mediate cell adhesion. This combination paints a picture of an epithelium that is simultaneously maintaining its identity, organizing its adhesive architecture, and broadcasting signals to its neighbors. The mesenchymal compartment, the Müllerian duct mesenchyme, is marked by a different and equally characteristic set of genes: WNT4, EMX2, POSTN, OSR1, VIM, DMRT genes, and the epithelial-to-mesenchymal transition regulators ZEB1 and ZEB2. The presence of EMT markers in a mesenchymal population underscores the developmental plasticity embedded in this tissue.

The most dramatic divergence between the sexes occurs in the mesenchyme. In male embryos, the Müllerian ducts regress under the influence of Anti-Müllerian Hormone, or AMH, the hormone secreted by the Sertoli cells of the developing testes. The single-cell data show that the regressing male mesenchyme is not simply a dying tissue but a transcriptionally active one with its own unique signature. It expresses a set of transcription factors — MSX1, MSX2, RUNX2, GATA5, DLX3 and DLX5 — along with signaling regulators including DKK4 and NRG1, the latter also known as Neuregulin. This finding reframes duct regression: rather than a passive collapse, it is an actively orchestrated program driven by specific regulatory genes switched on in the mesenchymal compartment.

Among the newly implicated genes, DKK4 stands out. DKK4 encodes a WNT antagonist, a class of molecules that dampens the Wnt signaling pathways so central to organ building. The study found that DKK4 responds to AMH induction, placing it downstream of the hormone that triggers regression in males. More strikingly, when DKK4 was ectopically expressed in female embryos, it was sufficient to induce duct regression. That a single secreted antagonist, acting in the mesenchyme, can drive the dismantling of the duct provides a mechanistic bridge between the endocrine signal, AMH, and the cellular execution of regression. It suggests that AMH does not act directly on every cell of the duct but instead recruits mesenchymal effectors such as DKK4, which then reshape the local signaling environment of the epithelium until the structure can no longer be maintained.

The female mesenchyme follows an entirely different script. Instead of the regressive program, the duct mesenchyme in females carries a molecular signature comprising SMARCA2, HMGA2, ZEB1, ZEB2, TWIST1, TWIST2 and DMRT2, together with persistent expression of FOXE1, OSR2 and HGF, Hepatocyte Growth Factor. HGF is a well-known growth and survival factor for epithelia, and its continued expression is consistent with a mesenchyme that supports and nurtures the epithelium rather than undermining it. The chromatin-associated factors HMGA2 and SMARCA2, together with the TWIST family of transcription factors, hint at a mesenchyme that is proliferative, migratory and architecturally engaged in shaping a duct that will grow and regionalize into the functional oviduct.

Within the developing female ducts, the single-cell analysis identified cell clusters that appear to reflect spatial pre-patterning of the duct before its later regionalization into distinct segments. This is a conceptually important observation. The mature oviduct is a regionally specialized organ, with different segments performing different functions in egg transport and albumin deposition, and embryologists have long wondered when and how this regional identity is established. The new data suggest that the groundwork is laid early: even before overt regionalization, the duct already contains spatially organized cell populations with distinct transcriptional profiles, implying that a hidden map of future compartments exists in the simple-looking embryonic tube.

Perhaps the most intriguing biological puzzle addressed by the study concerns the female chicken embryo itself. Unlike mammals, where both Müllerian ducts develop symmetrically in females, the chicken embryo shows an unusual pattern: the left duct differentiates into the reproductive tract while the right duct regresses. The prevailing assumption has been that this right-sided regression is mediated by AMH, just as bilateral regression is in males. The single-cell data, however, tell a different story. The regressing right duct in the female is transcriptionally distinct from the regressing ducts in the male and, crucially, lacks the population of regressing mesenchyme that defines the male program. In other words, whatever mechanism eliminates the right duct in females, it does not appear to recruit the same AMH-driven mesenchymal program that dismantles the ducts in males.

This asymmetry between male and female regression carries broad implications. It suggests that AMH signaling alone may not be sufficient to specify the full regressive program, or that the female right duct lacks the competence to respond in the same way, perhaps because of differences in hormone exposure, receptor expression, or the developmental timing of the two sides. It also highlights the chicken as a model in which the question can be asked directly: the same organ, in the same embryo, is subject to two different fates on the two sides of the body, providing an internal comparison that mammalian systems cannot offer. Understanding why the female right duct fails to mount the male-style regressing mesenchyme population could illuminate how AMH responsiveness is established and how developmental competence is encoded in mesenchymal tissues more generally.

More broadly, the study demonstrates the power of single-cell transcriptomics to resolve developmental questions that bulk methods could only approximate. By assigning precise gene expression signatures to the epithelial and mesenchymal compartments of the Müllerian duct, and by showing how those signatures diverge between the differentiating female duct, the regressing male duct and the regressing female right duct, the work provides a molecular framework for a process that has been described morphologically for over a century. The identification of DKK4 as an AMH-responsive, regression-inducing WNT antagonist offers a concrete entry point for future functional studies, while the catalog of mesenchymal transcription factors and signaling regulators in both sexes supplies a rich target list for dissecting how the reproductive tract is built, patterned and, when appropriate, dismantled. For developmental biologists, and for anyone interested in how the vertebrate body plan executes its most consequential decisions, the chicken embryo has just become considerably more informative.

Subject of Research: Single-cell transcriptomic analysis of Müllerian duct epithelial and mesenchymal differentiation and sex-specific regression in chicken embryos

Article Title: New insights into Müllerian duct differentiation provided by single cell transcriptomics in the chicken embryo

Article References: Tan, J. L., Barugahare, A., Major, A. T., & Smith, C. A. (2026). New insights into Müllerian duct differentiation provided by single cell transcriptomics in the chicken embryo. PLOS Genetics, 22(10), e1012302. https://doi.org/10.1371/journal.pgen.1012302

Image Credits: AI Generated

DOI: 10.1371/journal.pgen.1012302

Keywords: Müllerian duct, single-cell transcriptomics, chicken embryo, Anti-Müllerian Hormone, DKK4, WNT signaling, Müllerian duct mesenchyme, Müllerian duct epithelium, duct regression, sexual dimorphism, PLOS Genetics, reproductive tract development

The rationale for the study rests on a well-documented clinical observation. A high prevalence of concurrent PIK3CA and CTNNB1 mutations has been reported among patients with endometrial cancer, yet the functional relationship between the two pathways these genes control has remained murky. PIK3CA drives the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) cascade, a growth-promoting network that has long attracted drug developers. CTNNB1, which encodes β-catenin itself, feeds into the Wnt pathway, a transcriptional program implicated in development and, when dysregulated, in numerous cancers. Whether these two axes cooperate to fuel tumor growth, or whether one could be exploited therapeutically against the other, was an open question.

To answer it, the team assembled a panel of eleven endometrial cancer cell lines and tested three mechanistically distinct inhibitors: ICG-001, which blocks the interaction between β-catenin and its transcriptional co-activator CBP; ipatasertib, an AKT inhibitor; and rapamycin, a classic mTOR inhibitor. The results were strikingly asymmetric. ICG-001, but not the PI3K/AKT/mTOR pathway inhibitors, exhibited potent antiproliferative activity specifically in the cells harboring both CTNNB1 and PIK3CA mutations. In other words, the very pathway combination that had seemed like an obvious target for dual blockade turned out to be most vulnerable to a single intervention on the Wnt side.

Transcriptomic profiling helped explain why. When the double-mutant cells were treated with ICG-001, a series of canonical β-catenin target genes were downregulated, confirming that the drug was doing what it was designed to do at the transcriptional level. But the more revealing finding was what appeared in their place: signature genes related to proteotoxic stress and proteostasis disruption were significantly enriched. Proteostasis, the cellular system that governs the synthesis, folding, and disposal of proteins, is a delicate balance. Its collapse is a recognized form of lethal stress in cancer cells, and the gene expression data suggested that ICG-001 was pushing the double-mutant cells precisely in that direction.

The mechanistic follow-up experiments painted a vivid picture of a cell in crisis. ICG-001 treatment induced de novo protein synthesis, meaning the cells began churning out new proteins at an accelerated rate. At the same time, the researchers observed autophagosome formation, detectable as accumulation of the lipidated form of the protein LC3B (LC3B-II), a hallmark of the cell’s attempt to digest and recycle its own contents. Endoplasmic reticulum expansion, another sign of protein-folding overload, was evident, along with the accumulation of ubiquitinated proteins, the molecular equivalent of garbage piling up faster than the cell’s disposal machinery can clear it. Together, these changes indicate severe proteostasis collapse, a state in which the cell’s protein economy fails catastrophically.

What makes this mechanism particularly compelling is the selectivity. The double-mutant cells appear to be running their protein production machinery close to capacity, perhaps because the combined PIK3CA and CTNNB1 mutations impose unusual demands on translation and folding. When ICG-001 disrupts β-catenin/CBP-dependent transcription, the resulting imbalance between protein synthesis and protein quality control becomes lethal specifically for cells with this genetic background, while sparing cells that lack the double mutation. This kind of synthetic vulnerability, where a drug exploits a weakness created by a specific combination of mutations, is the holy grail of precision oncology, because it promises efficacy with a built-in therapeutic window.

The in vitro findings translated into animal models. Daily administration of ICG-001 demonstrated robust antitumor efficacy in xenograft models of CTNNB1/PIK3CA double-mutant endometrial cancer, meaning tumors grown from the double-mutant cells in mice shrank or stopped growing under treatment. Critically, examination of the xenograft tissues revealed marked ubiquitin accumulation, mirroring the proteostasis collapse seen in cultured cells and confirming that the same mechanism operates in living tumors. This consistency between cell culture and animal data strengthens the case that the observed vulnerability is not an artifact of the laboratory dish but a genuine biological dependency of these tumors.

The study also carries a cautionary message for the alternative strategy. Inhibitors of the PI3K/AKT/mTOR pathway have been extensively developed and tested across many tumor types, with mixed results, and the finding that ipatasertib and rapamycin failed to show preferential activity against the double-mutant endometrial cancer cells suggests that simply attacking the PIK3CA-driven arm of the network may not be the right approach for this subset. The interplay between the two pathways, whatever its details, does not make the PI3K axis the Achilles’ heel. Instead, the data redirect attention toward β-catenin/CBP inhibition as the more productive point of attack.

For patients, the implications are significant but tempered by the usual caveats of preclinical research. ICG-001 is an experimental tool compound, and the path from xenograft efficacy to an approved medicine involves medicinal chemistry optimization, safety profiling, and clinical trials in appropriately selected patients. The study nonetheless establishes a clear biomarker strategy: tumors carrying both PIK3CA and CTNNB1 mutations, identifiable through routine genomic sequencing, would be the candidate population for β-catenin-targeted therapy. Given the high prevalence of this double-mutation pattern in endometrial cancer, the addressable patient group could be substantial, offering hope in a disease where advanced-stage options are currently limited largely to chemotherapy, hormone therapy, and, more recently, immunotherapy for a subset of tumors.

The work also adds to a growing appreciation of proteostasis as a therapeutic target in cancer. Drugs that overload the protein-folding and degradation machinery, such as proteasome inhibitors in multiple myeloma, have already proven that stressing this system can be clinically effective. The present study suggests that transcriptional modulation of β-catenin can trigger a similar collapse in a genetically defined solid tumor, extending the concept into gynecologic oncology. As the authors and their collaborators at the National Cancer Center and the University of Tokyo note, these preclinical findings collectively highlight the vulnerability of PIK3CA/CTNNB1 double-mutant endometrial cancers to β-catenin inhibition and establish β-catenin/CBP inhibitors as a promising targeted therapeutic strategy for this specific genetic subset. Clinical validation will take years, but the study provides the mechanistic foundation and the biomarker logic needed to begin that journey.

Subject of Research: Therapeutic potential of β-catenin inhibition in PIK3CA/CTNNB1 double-mutant endometrial cancer

Article Title: Potential of β-catenin inhibitors as a novel therapeutic strategy for PIK3CA/CTNNB1 double-mutant endometrial cancer

Article References: Nakao, T., Kamata, R., Saito, H., Yamamoto, G., Morita, T. Y., Kinoshita, K., Takahashi, Y., Mashima, C., Yamauchi, T., Sakae, Y., Kamii, M., Nakai, K., Hakozaki, Y., Nakajima, H., Harano, K., Naito, Y., Mukohara, T., & Ohashi, A. (2026). Potential of β-catenin inhibitors as a novel therapeutic strategy for PIK3CA/CTNNB1 double-mutant endometrial cancer. Cell Death Discovery. https://doi.org/10.1038/s41420-026-03321-6

Image Credits: AI Generated

DOI: 10.1038/s41420-026-03321-6

Keywords: endometrial cancer, β-catenin, CTNNB1, PIK3CA, Wnt signaling, ICG-001, proteostasis, targeted therapy, xenograft models, PI3K/AKT/mTOR, proteotoxic stress, precision oncology

The research team, led by Nana Matoba, Jessica McAfee, Hyejung Won and Jason Stein at the University of North Carolina at Chapel Hill, deployed a massively parallel reporter assay, or MPRA, to interrogate 9,092 genetic variants associated with human cortical structure. The logic of the assay is elegant. Each candidate variant is synthesized as a short 150-base-pair segment of DNA, cloned into a plasmid upstream of a minimal promoter that drives a luciferase reporter gene, and tagged with a random 20-base-pair barcode. When the pooled library is introduced into cells, the amount of barcode RNA produced by each construct reflects the regulatory power of the DNA segment attached to it. By sequencing both the RNA transcripts and the plasmid DNA, researchers can calculate a transcription rate for every element, and by testing both alleles of a variant side by side, they can detect whether one version of the sequence drives expression more strongly than the other.

The cellular context matters enormously here. The team performed the assay in primary human neural progenitor cells, the fetal-derived stem cells that generate the neurons of the developing cortex. Previous work had shown that variants associated with cortical structure are enriched in regulatory regions active in these progenitors and colocalize with genetic effects on chromatin accessibility and gene expression in the same cells. This supports a model in which noncoding variants act during prenatal development, altering transcription factor binding and gene expression in progenitor cells, and thereby influencing decisions about cell proliferation and fate that ultimately determine cortical size in adulthood. The researchers transfected the library into 16 biological replicates, and after 24 hours split the cultures: half received a vehicle control, while half were treated with CHIR99021, a potent inhibitor of GSK3β that activates the Wnt signaling pathway, a key developmental signal known to influence brain size.

The results were striking in their scale and reproducibility. Regulatory activity measurements correlated between replicates with a median Pearson’s coefficient of 0.99, and the positive control promoters behaved exactly as expected. Among 17,837 elements tested under baseline conditions, 988 showed regulatory activity significantly above the negative controls, representing 918 variants drawn from 150 of the 198 cortical-structure-associated loci examined—meaning that 76 percent of the loci contained at least one variant with detectable regulatory function. More than half of the active variants also showed allelic effects, meaning one DNA letter change measurably altered transcription. The team dubbed these expression-modulating variants, or emVars, and they represent the strongest candidates for the true causal variants hiding within blocks of correlated genetic variation that have long frustrated geneticists.

Perhaps the most surprising finding came when the researchers asked what sequence features distinguished the active elements. Active elements were dramatically enriched in short interspersed nuclear elements, or SINEs—a class of retrotransposons, the so-called jumping genes that copy and paste themselves throughout the genome. Within the SINE family, the enrichment was driven almost entirely by Alu elements, primate-specific repeats that have expanded in prevalence alongside increases in brain size over human evolution. A typical Alu element carries two conserved sequences in its left arm, the A box and the B box, which function as promoters for RNA polymerase III. The most active MPRA elements sat precisely in this left arm, and elements containing both boxes showed the highest activity of all. Variants with the strongest allelic effects clustered near these promoter boxes, and even a scrambled negative control that accidentally contained a B-box-like sequence showed strong activity—a striking confirmation of the mechanism.

Skeptics might worry that such activity is an artifact of the episomal plasmid system, in which DNA is not packaged into chromatin as it would be in the native genome. The team addressed this concern with multiple lines of endogenous evidence. Fetal brain tissue shows among the lowest levels of repressive chromatin marks, such as H3K9me3 and H3K27me3, deposited on Alu elements of any tissue in the body, and the MPRA-active Alu elements are rarely repressed in fetal brain specifically. The active elements were also enriched for enhancer RNAs and promoter upstream antisense RNAs, noncoding transcripts previously shown to mediate enhancer-promoter communication through Alu sequences. Finally, using CUT&RUN profiling, the researchers showed that MPRA-active Alu elements are significantly enriched within binding sites of TFIIIC, a transcription factor complex associated with polymerase III and Alu activity. Together, these data suggest that the reporter activity reflects genuine regulatory potential in the developing brain.

The evolutionary implications are tantalizing. Alu elements can be dated by their accumulated mutations, measured as sequence divergence from the ancestral consensus. The younger Alu elements—those with fewer than 100 mismatches per thousand bases—showed significantly higher regulatory activity than older ones, particularly when located in the left arm of the element. Because Alu insertions have proliferated in the primate lineage in step with brain size expansion, the findings suggest that relatively recent retrotransposon insertions created new regulatory elements that influenced neurodevelopmental genes and may have contributed to the expansion of the human cortex. The authors caution that a neutral decay of regulatory potential in older elements over evolutionary time could also explain the pattern, but the convergence with known primate-specific biology makes the adaptive interpretation compelling.

The study also connected individual variants to specific transcription factors and, remarkably, to specific brain regions. Active elements were enriched for binding motifs of three transcription factor clusters—ZNF135/ZNF460, MEF2A-D and Zfx—and the magnitude of a variant’s allelic effect correlated strongly with how severely it disrupted a predicted motif. Disruption of RARA, RARG, ZNF135 and NR2F1 motifs produced the largest impacts. Intriguingly, the consensus sequences of recently evolved Alu subfamilies contain retinoic acid receptor binding sites, linking the transposon story to developmental signaling. Even more strikingly, when the team compared the regional pattern of a variant’s effect on cortical structure with the expression of the disrupted transcription factor across prenatal brain regions from the BrainSpan Atlas, they found significant correlations for seven variants. A variant that disrupts the RARG binding motif, for example, reduced surface area most strongly in regions where RARG expression was highest—suggesting that the regional specificity of genetic effects is governed by where the relevant transcription factors are actually present.

Wnt stimulation added another layer of complexity. Under CHIR treatment, the team detected a similar number of active elements, but 32 elements gained activity specifically under stimulation while seven lost it, and 12 variants showed allelic effects that differed significantly between conditions. One example, rs4670759, associated with the surface area of the inferior temporal cortex, showed enhanced activity and increased chromatin accessibility under Wnt stimulation; it sits in the promoter of CDC42EP3, a gene involved in actin cytoskeleton formation whose expression rises with Wnt activation, and the risk allele is predicted to disrupt a PLAGL2 motif that is itself upregulated by the pathway. Another variant, rs2802295 within an intron of FOXO3, showed an allelic effect only under stimulation near a Wnt-responsive element. The team then used CRISPR interference to silence that element in progenitor cells and confirmed that FOXO3 expression dropped—experimentally tying a cortical-structure-associated variant to its target gene in a condition-specific manner.

The study is not without limitations. The MPRA measures regulatory potential on episomal plasmids, and the overlap with endogenous chromatin accessibility quantitative trait loci was limited, indicating that native chromatin context modifies some effects. The analysis also focused on variants tested primarily in populations of European ancestry and did not address sex-dependent effects. Nevertheless, by experimentally separating correlated variants, identifying the transcription factors they disrupt, and demonstrating condition-dependent function, the work delivers a genome-scale functional framework for one of the most complex traits in human neuroimaging genetics. It transforms a catalog of statistical associations into a mechanistic hypothesis space—one in which ancient jumping genes, developmental signaling pathways and spatially patterned transcription factors jointly sculpt the most distinctive feature of the human brain.

Subject of Research: Functional characterization of noncoding genetic variants associated with human cortical structure using massively parallel reporter assays in neural progenitor cells

Article Title: Massively parallel assessment of gene regulatory activity at human cortical-structure-associated variants

Article References: Matoba, N., McAfee, J. C., Krupa, O., Beltran, A. A., Bell, J. L., Le, B. D., Valone, J. M., Min, H., Crawford, G. E., Raab, J. R., Won, H., & Stein, J. L. (2026). Massively parallel assessment of gene regulatory activity at human cortical-structure-associated variants. Nature Neuroscience. https://doi.org/10.1038/s41593-026-02454-2

Image Credits: AI Generated

DOI: 10.1038/s41593-026-02454-2

Keywords: cortical structure, massively parallel reporter assay, noncoding variants, Alu elements, neural progenitor cells, Wnt signaling, transcription factors, ENIGMA, gene regulation, brain development, retrotransposons, CRISPRi