Lysine demethylases, often abbreviated KDMs, are enzymes that remove methyl chemical groups from lysine residues on histone proteins, the spools around which DNA is wound inside every cell. This seemingly simple act of demethylation has profound consequences for chromatin architecture and gene expression. When KDMs malfunction, the delicate epigenetic balance that governs which genes are switched on or off can be disrupted, contributing to uncontrolled cell proliferation, evasion of programmed cell death, and the development of metastatic behavior. In breast cancer specifically, individual members of this enzyme family have previously been implicated in tumor progression and therapeutic resistance, but a holistic, multi-database portrait of the entire family has been conspicuously lacking.

To construct that portrait, the research team led by investigators at Tabriz University of Medical Sciences harnessed an impressive arsenal of publicly available bioinformatics platforms. They drew upon UALCAN for tumor versus normal expression comparisons, bc-GenExMiner for clinicopathological correlations, the Kaplan-Meier Plotter for survival analyses, cBioPortal for genomic alteration profiling, STRING and Cytoscape for protein interaction network construction, Enrichr for pathway enrichment, MethSurv for CpG methylation survival analysis, GSCALite for drug sensitivity correlations, and TIMER for immune infiltration assessments. All gene names were standardized to HGNC-approved symbols to ensure consistency across the disparate data sources, a methodological safeguard that strengthens the reliability of cross-platform integration.

The analysis revealed that KDM genes do not behave uniformly across breast cancer. Instead, they display sharply divergent expression patterns depending on the molecular subtype of the tumor. Genes including KDM1A, KDM1B, KDM4C, KDM4D, KDM4E, and KDM5A were significantly upregulated in triple-negative and basal-like breast cancers, the most aggressive and hardest-to-treat subtypes, while genes such as KDM2B, KDM3B, KDM4B, KDM6A, and KDM6B were markedly downregulated in the same contexts. Pairwise co-expression analysis within the triple-negative cohort identified two distinct modules: an oncogenic cluster anchored by a strong correlation between KDM1B and KDM5A, and a separate suppressor module linking KDM3B with PHF2. This architecture suggests that groups of demethylases may act cooperatively, either fueling or restraining tumor aggressiveness, rather than functioning as isolated molecular actors.

Survival analysis delivered some of the study’s most clinically resonant findings. Higher expression of KDM1B, KDM4A, KDM4B, KDM5A, KDM5C, KDM6A, and RSBN1 was significantly associated with improved overall survival, with KDM5C showing one of the strongest protective effects. In stark contrast, elevated KDM5B expression predicted shorter overall survival and poorer relapse-free survival, marking it as a candidate adverse prognostic marker. Relapse-free survival analysis extended this picture further, implicating elevated KDM5A, KDM5B, and KDM7A in earlier relapse while confirming the protective associations of more than a dozen other family members. Taken together, these data suggest that a patient’s KDM expression signature could one day inform risk stratification and guide the intensity of adjuvant therapy.

Genomic alteration analysis through cBioPortal, drawing on more than one thousand invasive breast carcinoma samples, identified KDM5B as the most frequently altered KDM gene, with amplification emerging as the dominant mechanism of dysregulation in roughly eighteen percent of tumors. Crucially, alterations in KDM5B, KDM2A, and KDM4C were strongly enriched in metastatic disease, aggressive histologic subtypes including infiltrating ductal and metaplastic carcinomas, and hormone receptor-negative phenotypes. Many of these amplifications and missense mutations clustered within functional domains such as the JmjC catalytic core and DNA-binding regions, implying that the alterations are not passenger events but likely enhance demethylase activity in ways that actively promote tumor progression. Protein interaction network modeling pinpointed KDM6A, KDM6B, KDM1A, KDM1B, and PHF8 as the central regulatory hubs within the broader epigenetic landscape of breast cancer.

Perhaps the most therapeutically provocative dimension of the study involves drug sensitivity. Cross-referencing KDM expression with large pharmacogenomic datasets from the Genomics of Drug Sensitivity in Cancer and Cancer Therapeutics Response Portal revealed that most KDM genes correlate negatively with drug sensitivity, meaning their overexpression may actively foster chemotherapy resistance. KDM2B stood out as the linchpin, showing the strongest and most consistent correlations across both datasets. Elevated KDM2B expression was linked to reduced sensitivity to Methotrexate, Doxorubicin, PX-12, I-BET-762, and Belinostat, clinically relevant agents spanning antifolate, anthracycline, redox-targeting, bromodomain-inhibiting, and HDAC-inhibiting classes. Prior experimental work in glioblastoma and other models has shown that KDM2B inhibition impairs cancer stem-like cell survival by inducing DNA damage and apoptosis, providing a plausible mechanistic rationale for how targeting this enzyme could resensitize tumors to standard chemotherapy.

The study also uncovered a striking methylation dimension. Using MethSurv, the researchers identified dozens of individual CpG sites within KDM genes whose methylation status was significantly associated with patient survival, including thirty-five prognostically relevant CpG sites in KDM2B alone and forty-six in KDM4B. This epigenetic crosstalk between histone demethylase genes and their own DNA methylation patterns underscores the layered complexity of cancer epigenetics and hints at potential biomarker applications beyond simple mRNA measurement. Meanwhile, enrichment analysis confirmed that KDM family genes are centrally involved in histone lysine demethylation, chromatin remodeling, 2-oxoglutarate-dependent dioxygenase activity, and metabolic pathways, connecting these enzymes to the metabolic reprogramming that is increasingly recognized as a hallmark of malignancy.

Immune infiltration analysis through TIMER added yet another layer of significance. KDM5A, KDM6A, and KDM7A expression correlated strongly and positively with CD8-positive T cell infiltration, suggesting these demethylases may help shape anti-tumor immunity. KDM2B showed notable associations with dendritic cells, neutrophils, CD4-positive T cells, and B cells, while KDM6A correlated with macrophage presence. Given the central role of tumor immune microenvironment composition in determining response to immunotherapy, these correlations suggest that KDM expression profiles could eventually help predict which patients are most likely to benefit from immune checkpoint inhibitors. The authors are careful to acknowledge the principal limitation of their work: it is entirely computational, relying on public databases without wet-lab experimental validation. Future studies employing in vitro knockdown assays and in vivo models will be essential to confirm these associations and dissect the underlying molecular mechanisms. Nevertheless, by synthesizing expression, survival, mutation, methylation, drug sensitivity, and immune data into a single unified framework, this investigation delivers the most complete picture to date of how the lysine demethylase family operates in breast cancer, and it does so with a clarity that should accelerate the translation of epigenetic insights into genuinely personalized therapeutic strategies.

The biological significance of lysine demethylation stems from the fact that methylated lysine residues on histone tails can carry distinct methylation states — mono-, di-, or trimethyl — and each state conveys a different transcriptional message. The KDM family reflects this complexity, comprising two mechanistically distinct classes: the flavin adenine dinucleotide-dependent amine oxidases such as KDM1A and KDM1B, and the larger group of JmjC-domain proteins that require iron and 2-oxoglutarate as cofactors. This enzymatic split has practical consequences for drug discovery, since the two classes are inhibited through entirely different chemical strategies, and several small-molecule demethylase inhibitors are already being evaluated in early-phase clinical trials for hematologic and solid malignancies.

The subtype-specific expression patterns observed in this study align with a broader principle in breast cancer biology: epigenetic regulators frequently act in a context-dependent fashion, behaving as oncogenes in one molecular background and tumor suppressors in another. This duality helps explain why broad demethylase inhibition may not be a viable therapeutic strategy, and why a precision approach — one that profiles a patient’s tumor for specific KDM alterations before selecting an epigenetic drug — is likely to be more fruitful.

The strong correlations between KDM expression and immune cell infiltration also connect the family to the emerging field of epigenetic immunomodulation. Chromatin regulators are increasingly understood to control the expression of immune checkpoints, antigen presentation machinery, and cytokine signaling pathways, and combining epigenetic drugs with immune checkpoint blockade has become an active area of clinical investigation. The observed links between KDM5A, KDM6A, and CD8-positive T cell infiltration provide a computational foundation for testing such combinations in breast cancer settings.

It is worth noting that the study’s findings derive entirely from curated patient cohorts within platforms built on The Cancer Genome Atlas and related resources, and the reported effect sizes — such as the hazard ratio of 1.5 for KDM5B — represent statistical associations rather than demonstrated causation. Translating these computationally derived hypotheses into clinical utility will require laboratory validation and, ultimately, prospective testing of KDM-based biomarkers in independent patient populations.

Subject of Research: Integrated bioinformatics profiling of the lysine demethylase gene family in breast cancer

Article Title: Integrated bioinformatics profiling of the lysine demethylase gene family in breast cancer

Article References: Mirzaei, Z., Barati, T., Ebrahimi, A., & Khaniani, M. S. (2026). Integrated bioinformatics profiling of the lysine demethylase gene family in breast cancer. Discover Biotechnology, 3(1), Article 9. https://doi.org/10.1007/s44340-026-00055-0

Image Credits: AI Generated

DOI: 10.1007/s44340-026-00055-0

Keywords: Integrated, bioinformatics, profiling, lysine, demethylase, gene, family, breast, cancer, scientific research

ER+ breast cancer represents approximately 70% of all breast cancer cases worldwide and is frequently managed with endocrine therapies that disrupt estrogen signaling, a major driver of tumor growth. Although these therapies have improved patient outcomes, a significant challenge remains: a substantial fraction of tumors develop resistance, leading to relapse and metastatic progression. The recent approval and use of CDK4/6 inhibitors in combination with endocrine therapy have further enhanced progression-free survival in high-risk patients. However, not all patients benefit, spotlighting an urgent need to understand the molecular basis of this resistance phenomenon.

At the heart of the team’s investigation is the JNK signaling pathway, a critical cellular mechanism generally understood as both a modulator of stress-induced apoptosis and a regulator of cell cycle arrest. This pathway functions akin to an intracellular alarm system, activated upon cellular stressors such as DNA damage, oxidative stress, or cytotoxic therapies. Activation of the JNK pathway promotes processes that either halt cell proliferation or induce programmed cell death, mechanisms crucial for eliminating damaged or potentially oncogenic cells.

The researchers, led by Associate Professor Liz Caldon and Dr. Sarah Alexandrou, employed an innovative genome-wide CRISPR-Cas9 screen to systematically inactivate every gene across the genome in cultured ER+ breast cancer cells. This approach enabled them to pinpoint which genes, when silenced, confer resistance to combined endocrine and CDK4/6 inhibitor therapies. Strikingly, they discovered that disruption of multiple components of the JNK pathway, particularly the upstream kinase MAP2K7, allowed cancer cells to ignore therapeutic stress signals, continuing unabated proliferation and survival despite treatment.

Further validation involved analysis of tumor biopsies obtained from 78 ER+ breast cancer patients. Tumors exhibiting diminished JNK pathway activity correlated strongly with inferior therapy response and worse clinical outcomes. These findings collectively suggest that impaired JNK signaling functions as a molecular shield, permitting cancer cells to evade the cytostatic and cytotoxic effects of endocrine agents and CDK4/6 inhibitors by effectively silencing the stress alarms that would otherwise trigger senescence or apoptosis.

The revelation that the JNK pathway can act as a tumor suppressor contrasts with its previously held reputation in some cancer contexts as primarily tumor-promoting, underscoring the complexity of signal transduction networks within different cellular milieus. Within ER+ breast cancer, the balanced activity of the JNK pathway appears imperative; both hyperactivation and loss can perturb homeostasis, but loss notably drives therapeutic resistance. This dualistic role highlights a critical nuance in the pathway’s biology that can inform future therapeutic strategies.

Beyond mechanistic insights, the study offers translational promise. By developing biomarkers to assess JNK pathway functionality, clinicians could stratify patients prior to therapy initiation, identifying those unlikely to benefit from standard endocrine and CDK4/6 inhibitor regimens. This stratification would pave the way for personalized medicine, steering resistant patients toward alternative or adjunctive treatments and thereby optimizing clinical outcomes while minimizing unnecessary toxicity.

The Garvan team is spearheading ongoing research to unearth alternative therapeutic options tailored to cancers with suppressed JNK signaling. These efforts include screening for drugs capable of reactivating the pathway or exploiting vulnerabilities engendered by its silencing. The ultimate goal is a paradigm in which a patient’s tumor signaling profile guides bespoke treatment algorithms, maximizing efficacy and extending survival.

Importantly, this research underscores the value of integrating sophisticated genetic screening tools like CRISPR with patient-derived data to unravel complex biological resistance mechanisms. By combining high-throughput functional genomics with clinical sample analysis, the study establishes a robust framework for future oncology research aimed at overcoming drug resistance.

The implications of these findings extend beyond ER+ breast cancer, suggesting that similar stress response pathways may govern therapeutic resistance in other malignancies. As drug resistance remains a pervasive barrier in oncology, insights from the JNK pathway and its regulatory networks open new frontiers for investigation across cancer types.

This work was made possible through funding from diverse sources, including the National Breast Cancer Foundation and philanthropic awards, highlighting the synergistic role of public and private support in advancing cancer research. The team also acknowledges the important contributions of consumer advocates, emphasizing patient involvement in shaping impactful research agendas.

The promise embodied by this study is profound: in the near future, assessing the activity of cellular stress pathways like JNK may become routine in clinical oncology, informing decisions that tailor treatments to the molecular fingerprints of each tumor. For patients battling ER+ breast cancer, such precision could redefine prognosis and transform therapeutic landscapes.

Subject of Research: People

Article Title: JNK pathway suppression mediates insensitivity to combination endocrine therapy and CDK4/6 inhibition in ER+ breast cancer

News Publication Date: 18-Aug-2025

Web References:
http://dx.doi.org/10.1186/s13046-025-03466-9

Image Credits: Garvan Institute

Keywords: Breast cancer, Drug resistance, Signal transduction, JNK pathway, Signaling pathways, Cancer treatments, Medical treatments, Cancer medication, Cancer, Estrogen receptors, Senescence

PCD encompasses several distinct pathways, each with unique mechanistic features and implications for cancer biology. The ubiquitin-proteasome system (UPS) is a key regulatory mechanism that governs cellular homeostasis and influences the fate of cells undergoing apoptosis, autophagy, necroptosis, ferroptosis, and pyroptosis. These processes are not merely cellular responses to stress or damage but rather intricately linked to the survival and proliferation of cancer cells. For instance, USPs can either mediate or inhibit these pathways, posing essential questions regarding their functional roles in specific cancer types, such as breast cancer.

Apoptosis has garnered extensive attention as a crucial regulatory mechanism in preventing tumor growth. However, a profound challenge arises as many breast cancer cells develop resistance to apoptotic signals, allowing for uncontrolled cellular proliferation. Investigations into USPs such as USP22 and USP7 reveal their ability to modulate essential proteins like c-Myc and p53, which play pivotal roles in apoptosis regulation. By influencing these critical factors, USPs may act as double-edged swords, either promoting cell death or enhancing survival, thus contributing to the heterogeneous nature of breast tumors.

The paradoxical role of autophagy in breast cancer further complicates the landscape of PCD. Autophagy, a cellular process for degradation and recycling of cellular components, may function as a tumor suppressor or as a survival mechanism, depending on the context. The involvement of USPs, particularly USP8 and USP13, in regulating autophagy-related proteins like Beclin1 and p62/SQSTM1 suggests an intricate balance that may determine whether autophagy inhibits or promotes tumor survival. Understanding these dynamics may open new avenues for treatment, allowing for the development of strategies that can exploit this process effectively.

Emerging alternatives to classic apoptotic pathways have introduced additional complexities into the PCD discussion. Ferroptosis, characterized by iron-dependent cell death, has recently emerged as a promising target for therapeutic interventions, particularly in aggressive breast cancer subtypes such as triple-negative breast cancer (TNBC). Recent studies underscore the involvement of USPs like USP7 and USP35 in regulating this pathway, emphasizing the potential of targeting iron metabolism and oxidative stress to manipulate cancer cell fate. This focus on non-apoptotic death pathways indicates a significant shift in cancer therapy, encouraging the exploration of previously overlooked mechanisms.

Another fascinating aspect of PCD involves pyroptosis, an inflammatory form of programmed cell death that serves not only as a cytotoxic mechanism but also as an immune response amplifier. The role of USPs in modulating this pathway, particularly through interactions with gasdermin E (GSDME), offers fresh insights into immune evasion strategies employed by tumors. Pyroptosis represents a novel target for enhancing immune responses against tumors, potentially leading to improved outcomes in patients with breast cancer resistant to conventional therapies.

Challenges in breast cancer management are exacerbated by the tumor’s ability to metastasize and develop resistance to multiple treatment modalities. USPs contribute to these processes, highlighting their dual role in supporting cancer cell survival while simultaneously promoting mechanisms driving metastasis. The crosstalk between USPs and various PCD pathways, especially in less understood processes like necroptosis and anoikis, may hold critical insights into the progression of breast cancer. Elucidating these connections may reveal novel therapeutic strategies aimed at reviving the efficacy of existing treatments or establishing new targets for intervention.

As research in this area progresses, the potential for clinical applications rooted in the modulation of USPs and PCD pathways continues to expand. A deeper understanding of these molecular interactions could guide the development of targeted therapies that harness the complex interplay between cancer cells and their microenvironment. This endeavor aligns with the increasing emphasis on personalized medicine, where treatment strategies are tailored to the unique molecular profiles of individual tumors.

The insights garnered from investigating USPs’ role in PCD offer a promising frontier in breast cancer research. By effectively targeting these proteases, there is potential to reshape therapeutic approaches, neutralizing the adaptive capabilities of tumor cells and providing better outcomes for patients. The complexity inherent in the regulation of programmed cell death underscores the need for ongoing research into the molecular underpinnings of breast cancer, further driving innovation in therapeutic development.

With the burgeoning knowledge surrounding USPs and PCD mechanisms in breast cancer, it is imperative that future studies focus on delineating the specific pathways and molecular interactions at play. As scientists aim to unlock the intricacies of these mechanisms, this research underscores a critical turning point in understanding not only breast cancer but also the broader landscape of oncology. Continued exploration of these pathways holds the promise of pioneering novel strategies that can improve patient outcomes and offer hope in the ongoing battle against cancer.

Subject of Research:
Ubiquitin-specific proteases in programmed cell death of breast cancer cells.

Article Title:
Role of ubiquitin-specific proteases in programmed cell death of breast cancer cells.

News Publication Date:
2025

Web References:
N/A

References:
Wen Yan, Shasha Xiang, Jianbo Feng, Xuyu Zu, Role of ubiquitin-specific proteases in programmed cell death of breast cancer cells, Genes & Diseases, Volume 12, Issue 3, 2025, 101341.

Image Credits:
Genes & Diseases

Keywords:
Breast cancer, Programmed cell death, Ubiquitin-specific proteases, Apoptosis, Autophagy, Ferroptosis, Pyroptosis, Cancer therapy, Drug resistance, Metastasis.