MYSM1, short for Myb-like, SWIRM and MPN domains 1, is best known as a histone H2A deubiquitinase, an enzyme that removes ubiquitin tags from histone H2A, the protein spool around which DNA is wound. By erasing a specific mark called H2A lysine 119 ubiquitination, which is deposited by the Polycomb repressive complex 1 and generally silences genes, MYSM1 helps keep portions of the genome accessible and active. It has well-established roles in blood cell development and immune regulation, and recent work has implicated it in breast, colorectal, and prostate cancers. What remained unclear until now was whether it plays any role in cervical cancer, a question the new study set out to answer systematically.

The researchers began by mining public transcriptome resources, including The Cancer Genome Atlas, the Genotype-Tissue Expression project, and the Human Protein Atlas, to chart where MYSM1 is expressed across the full spectrum of human cancers. The pan-cancer survey showed that MYSM1 is aberrantly expressed in many tumor types, but the most striking finding was its profound downregulation in cervical cancer tissues compared with healthy cervical tissue. When the team cross-referenced MYSM1 levels with clinical information, high expression correlated with more benign clinicopathological characteristics, consistent with the idea that the protein acts as a brake on tumor progression. Survival analyses drawn from TCGA, an independent dataset called GSE44001, and the investigators’ own cohort of 44 paired cervical cancer specimens reinforced this picture.

To move beyond correlation, the scientists manipulated MYSM1 in cervical cancer cell lines, including HeLa and SiHa cells, using both lentiviral knockdown and overexpression approaches. When MYSM1 was silenced, the cells became more aggressive: proliferation measured by cell counting assays accelerated, colonies grew larger and more numerous in colony formation tests, and the cells migrated more readily through Transwell membranes. Conversely, restoring MYSM1 suppressed these malignant behaviors. The pattern held in living systems as well, with in vivo experiments confirming that the enzyme restrains tumor growth. The team then asked what cellular program MYSM1 triggers, and the evidence pointed squarely at autophagy, the conserved process by which cells digest their own components in double-membraned vesicles that fuse with lysosomes.

Autophagy has a complicated relationship with cancer, sometimes helping tumor cells survive metabolic stress and sometimes pushing them into autophagic cell death. In this study, MYSM1 expression was accompanied by clear biochemical and visual signatures of heightened autophagy. Western blotting revealed an increased ratio of LC3-II to LC3-I, the lipidated form of the microtubule-associated light chain 3 that decorates autophagosomal membranes. Immunofluorescence microscopy showed abundant LC3 puncta in the cytoplasm, and transmission electron microscopy captured the ultrastructural hallmarks of autophagic vesicles. Critically, when the authors blocked autophagy with chloroquine, the anti-proliferative and anti-migratory effects of MYSM1 largely disappeared, demonstrating that the autophagy program is not a bystander but the functional engine of MYSM1’s tumor suppression.

The next challenge was to identify how MYSM1, a nuclear chromatin enzyme, communicates with the autophagy machinery in the cytoplasm. Using chromatin immunoprecipitation sequencing, or ChIP-Seq, combined with transcriptomic profiling and correlation analyses against TCGA cervical cancer data, the researchers screened for downstream genes that are both bound by MYSM1 and expressionally dependent on it. Among roughly twenty candidate targets, one gene stood out: ITPR1, which encodes the inositol 1,4,5-trisphosphate receptor type 1, a large calcium channel embedded in the endoplasmic reticulum membrane. Gene Ontology, KEGG pathway, and Gene Set Enrichment analyses all connected ITPR1 to autophagy-related biological processes, and functional rescue experiments confirmed that ITPR1 mediates the anti-tumor effects of MYSM1 by acting as an inducer of autophagy.

Mechanistically, the picture that emerges is elegant. MYSM1 binds near the ITPR1 locus and removes repressive H2A ubiquitin marks, opening the chromatin and allowing the gene to be transcribed. The resulting ITPR1 channels modulate calcium release from the endoplasmic reticulum, a signal long known to feed into autophagosome initiation through autophagy-related proteins such as ATG5 and ATG7. With ITPR1 cranked up, cervical cancer cells experience elevated basal autophagy that tips them toward growth arrest and cell death rather than uncontrolled division. Like MYSM1, ITPR1 was found to be downregulated in the 44 paired clinical tumor specimens, and its abundance correlated with favorable clinical phenotypes, suggesting that the entire axis degrades together as the disease advances.

The study went a step further by asking whether variation in the MYSM1 and ITPR1 genes influences who develops cervical cancer in the first place. Using Mendelian randomization, a statistical framework that employs genetic variants as natural experiments, the team analyzed data from the GWAS Catalog to test whether genetically predicted expression of the two genes is associated with cervical cancer susceptibility. The results revealed a modest, suggestive genetic association, a finding that stops short of proving causation but adds a population-level dimension to the cellular and tissue-level evidence. Receiver operating characteristic analyses indicated that MYSM1 and ITPR1, individually and especially in combination, hold diagnostic potential for distinguishing tumor from normal cervical tissue, while survival curves in the clinical cohort hinted at prognostic value.

For the clinic, the implications are twofold. As a biomarker, the combined signature of MYSM1 and ITPR1 expression could one day help stratify patients or flag early disease, complementing existing screening approaches. As a therapeutic target, the pathway suggests strategies to restore MYSM1 function or pharmacologically activate ITPR1-driven calcium signaling to re-engage autophagic cell death in tumor cells. Such approaches remain distant, and the authors caution that the Mendelian randomization evidence is only suggestive and that the regulatory axis will need validation in larger, independent cohorts. Still, identifying an epigenetic switch that connects chromatin state to an autophagic tumor-suppression program offers a fresh molecular entry point into a cancer for which the dominant known driver, human papillomavirus, has long overshadowed other mechanisms.

The research, supported by the National Natural Science Foundation of China and regional science programs in Shaanxi and Xi’an, exemplifies a growing trend in translational oncology: starting from public multi-omics data, narrowing candidates through epigenomic and transcriptomic screens, and closing the loop with mechanistic experiments and patient samples. In doing so, it elevates MYSM1 from a hematopoietic and immunological curiosity to a candidate tumor suppressor in the cervix, and it positions the MYSM1–ITPR1–autophagy axis as a pathway worth watching as researchers seek new diagnostic and therapeutic leverage against cervical cancer.

Now, a study in Genes & Diseases reports a previously unrecognized epigenetic route through which the iron-responsive protein IRP1 collaborates with the transcription factor ARID3A to suppress ferroptosis and promote chemoresistance. The work links iron sensing to chromatin regulation and identifies a pathway that could be exploited therapeutically.

Across pancreatic cancer specimens, the authors find that both IRP1 and ARID3A are highly expressed and correlate with poor chemotherapy outcomes and unfavorable patient survival. In cell-based functional assays, elevating either protein enhances proliferation and increases resistance to gemcitabine, while silencing IRP1 or ARID3A restores chemosensitivity and suppresses tumor growth in models.

Mechanistically, intracellular iron accumulation drives IRP1 into the nucleus, where it physically associates with ARID3A. Rather than altering transcription solely through classic repression, the IRP1–ARID3A complex remodels chromatin dynamics to reduce accessibility at the cytoglobin (CYGB) promoter. This epigenetic shift suppresses CYGB expression without relying on direct transcriptional shutdown.

CYGB, in turn, plays a role in maintaining redox balance and regulating oxidative stress responses. When CYGB is diminished, pancreatic cancer cells show reduced lipid peroxidation, less reactive oxygen species accumulation, and stronger survival under ferroptosis-inducing conditions. The study connects these biochemical changes directly to the observed drug-resistant phenotype.

Crucially, restoring CYGB or disrupting the IRP1–ARID3A interaction reverses the ferroptosis-resistant state, resensitizing cells to ferroptosis and improving gemcitabine efficacy. In vivo, combining ferroptosis-relevant interventions with suppression of this signaling axis markedly restricts tumor progression.

The findings position the IRP1–ARID3A–CYGB axis as a central determinant of ferroptosis resistance in pancreatic cancer. By uniting iron metabolism, epigenetic control, and regulated cell death, the work offers a mechanistic basis for pairing chemotherapy with ferroptosis-targeting strategies in patients who do not respond to standard treatment.

Subject of Research: Ferroptosis resistance and chemoresistance in pancreatic cancer via IRP1–ARID3A–CYGB epigenetic regulation

Article Title: IRP1/ARID3A complex promotes pancreatic cancer chemoresistance by suppressing CYGB-related ferroptosis

News Publication Date:

Web References: http://dx.doi.org/10.1016/j.gendis.2025.101866

References:

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Keywords: pancreatic cancer; ferroptosis; IRP1; ARID3A; CYGB; chemoresistance; epigenetics; iron metabolism; gemcitabine

Prostate cancer, particularly its castration-resistant form, represents a formidable clinical challenge due to its ability to evade androgen deprivation therapies and conventional chemotherapy. Docetaxel remains a cornerstone treatment for advanced stages, yet resistance invariably develops, compromising patient outcomes. The newly reported findings spotlight the crucial involvement of histone lactylation in orchestrating cellular pathways that promote this resistance, thereby offering key insights into the molecular sabotaging of chemotherapeutic efficacy.

Histone proteins, fundamental components of chromatin, undergo diverse chemical modifications that influence DNA accessibility and transcriptional activity. Lactylation, the addition of a lactyl group to lysine residues on histones, has emerged as a unique regulator linking cellular metabolism to epigenetic control. This study demonstrates that elevated lactylation levels are prevalent in CRPC cells exhibiting docetaxel resistance, suggesting a direct connection between metabolic shifts and epigenetic reprogramming in cancer progression.

Delving into the mechanistic landscape, researchers identified that the modulation of the actin-binding protein Calponin 1 (CNN1) acts as a central mediator in this pathway. CNN1, traditionally associated with cytoskeletal dynamics, has been co-opted in resistant prostate cancer cells to activate autophagy—a self-digestive process that enables tumor cells to survive under therapeutic stress. This autophagic induction not only facilitates cell survival but also enforces cell cycle arrest, enabling cancer cells to enter a quiescent-like state refractory to chemotherapy.

The intricate link between histone lactylation and CNN1-driven autophagy paints a complex picture whereby metabolic rewiring influences chromatin state, which in turn governs cytoskeletal and survival pathways. This cascade ultimately supports tumor cell endurance against docetaxel, highlighting a multifaceted resistance mechanism that transcends classical genetic mutations and driver oncogene paradigms.

Moreover, the study utilized state-of-the-art biochemical assays and chromatin immunoprecipitation sequencing to establish a comprehensive mapping of lactylated histone sites correlating with upregulated CNN1 expression. These epigenetic marks were found to be enriched near genes implicated in autophagy regulation and cell cycle checkpoints, offering a direct transcriptional basis for the observed phenotypes in resistant tumor cells.

Importantly, pharmacologic inhibition of histone lactylation or genetic silencing of CNN1 significantly sensitized CRPC cells to docetaxel, effectively reversing resistance phenotypes in vitro and in murine xenograft models. This therapeutic vulnerability underscores the translational potential of targeting this chromatin-metabolic axis to enhance chemotherapy outcomes in advanced prostate cancer.

The findings also shed light on the dynamic interplay between tumor metabolism and epigenetic modulation. Increased intracellular lactate levels, often a hallmark of the cancer-associated Warburg effect, serve as substrates for histone lactylation, effectively linking metabolic byproducts to gene expression changes that support tumor survival. This metabolic-epigenetic nexus represents a paradigm shift in understanding how cancer cells leverage altered metabolism to epigenetically sculpt resistance phenotypes.

Intriguingly, the autophagy induced downstream of CNN1 activity does not merely act as a cytoprotective mechanism; it also contributes to the cell cycle arrest state, allowing cancer cells to evade docetaxel’s cytotoxic effects, which predominantly target proliferative cells. This dual role enhances tumor resilience, effectively creating a sanctuary where tumor cells persist unharmed during chemotherapy, ready to reinitiate growth post-treatment.

The study further explores how blockade of autophagy flux in CNN1-overexpressing cells disrupts this protective niche, reinstating the sensitivity of prostate cancer cells to chemotherapy. This suggests that combinatorial treatment regimens targeting histone lactylation, CNN1 function, and autophagic pathways could synergize to circumvent therapy resistance.

Beyond its immediate clinical relevance, this research advances the broader understanding of epigenetic modifiers as dynamic effectors in cancer progression. Histone lactylation emerges as a versatile post-translational mark integrating metabolic cues with chromatin architecture, adding complexity to the epigenetic code influencing tumor biology.

The implications extend to biomarker development, as levels of histone lactylation or CNN1 expression could serve as predictive indicators of docetaxel resistance. Such biomarkers would facilitate personalized treatment strategies, enabling early identification of resistant tumors and the prompt initiation of alternative or adjunctive therapies.

From a therapeutic development standpoint, the enzymes responsible for adding and removing lactyl groups on histones represent promising drug targets. Manipulating these epigenetic ‘writers’ and ‘erasers’ offers an innovative strategy to modulate chromatin states, reverse resistance mechanisms, and sensitize tumors to existing chemotherapies.

This groundbreaking work also encourages reevaluation of metabolic interventions in oncologic treatment, emphasizing the intricate connections between metabolite availability, epigenetic regulation, and cellular survival. Targeting metabolic pathways that fuel aberrant lactylation might disrupt the resistance circuitry at its origin.

Collectively, this study provides compelling evidence that epigenetic modifications like histone lactylation are not mere passive markers but active players in cancer drug resistance and progression. By uncovering the CNN1-mediated autophagy and cell cycle arrest axis, the research opens new horizons in tackling the clinical conundrum of chemotherapy failure in CRPC.

Future investigations are poised to decipher the full spectrum of histone lactylation targets across diverse malignancies, expanding the therapeutic relevance of these findings beyond prostate cancer. Additionally, exploring the crosstalk between lactylation and other histone modifications could unveil cooperative networks governing tumor cell fate decisions under therapeutic pressures.

In summary, the revelation that histone lactylation modification orchestrates docetaxel resistance and tumor progression via a CNN1-autophagy-cell cycle axis marks a transformative milestone in cancer epigenetics. This knowledge lays a robust foundation for the development of novel epigenetic-metabolic therapies designed to outwit tumor resilience mechanisms and improve survival for patients grappling with castration-resistant prostate cancer.

Subject of Research: Histone lactylation modification’s role in docetaxel resistance and tumor progression in castration-resistant prostate cancer.

Article Title: Histone lactylation modification promotes docetaxel resistance and tumor progression through CNN1-Mediated autophagy and cell cycle arrest in Castration-resistant prostate cancer.

Article References: Mao, R., Chen, X., Fu, X. et al. Histone lactylation modification promotes docetaxel resistance and tumor progression through CNN1-Mediated autophagy and cell cycle arrest in Castration-resistant prostate cancer. Cell Death Discov. (2026). https://doi.org/10.1038/s41420-026-03141-8

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41420-026-03141-8