Prostate cancer remains a leading cause of cancer-related morbidity and mortality globally, particularly in advanced stages where resistance to conventional androgen receptor-targeting therapies emerges. Approximately 30 to 40 percent of advanced prostate tumors exhibit basal-like gene expression programs, which are often linked to poor prognosis. Additionally, stem cell-like (SCL) tumor states have been implicated as a major mechanism by which tumors evade androgen receptor-targeted treatments, highlighting the urgent need for deeper molecular insights.

Through integrative transcriptomic analyses encompassing both primary prostate cancer (n=493) and castration-resistant prostate cancer (CRPC) cohorts (n=208), the researchers established a robust correlation between elevated CREB5 expression and the activation of basal-like and stem cell-associated gene signatures. This suggests that CREB5 operates at the nexus of transcriptional networks that endow tumor cells with stem-like properties and aggressive behavior.

Biochemical assays and chromatin immunoprecipitation sequencing (ChIP-seq) further revealed that CREB5 directly interacts with AP-1 family transcription factors, such as FOS and JUN, binding regulatory elements of AP-1 genes. This interaction amplifies oncogenic transcriptional cascades that foster tumor progression and cellular plasticity, key hallmarks of metastatic and therapy-resistant prostate cancer.

Functional experiments underscored the oncogenic potential of CREB5. Forced overexpression of CREB5 in prostate cancer cell lines resulted in enhanced colony formation in vitro and accelerated tumor growth in xenograft models, unequivocally demonstrating its tumor-promoting capabilities. Conversely, CREB5 knockdown impaired tumorigenicity, indicating the transcription factor’s essential role in maintaining aggressive cancer phenotypes.

Notably, the study’s analysis extended to comparing the expression of androgen receptor splice variant AR-V7 in CRPC tumors stratified by CREB5 levels. High CREB5 expression was associated with increased AR-V7, a marker of resistance to androgen deprivation therapies, suggesting a coordinated mechanism by which CREB5 contributes to therapeutic evasion and disease progression.

Genomic profiling also revealed that tumors with elevated CREB5 harbor distinct somatic alterations, further distinguishing them from low CREB5-expressing tumors. These genetic differences likely synergize with CREB5-driven transcriptional programs to potentiate malignant transformation and metastatic dissemination.

The findings highlight CREB5 not just as a passive biomarker but as a central driver orchestrating transcriptional states that endow tumor cells with plasticity and stemness, thereby promoting tumor aggressiveness. This positions CREB5 as a promising therapeutic target, particularly in androgen receptor-independent prostate cancer variants that currently lack effective treatments.

The research team advocates for the development of novel interventions aiming to disrupt CREB5 activity or its downstream effectors, potentially overcoming resistance mechanisms and improving outcomes for patients with advanced prostate cancer. Future studies are warranted to elucidate the precise molecular pathways mediated by CREB5 and to assess the efficacy of CREB5 inhibition in preclinical and clinical settings.

This study delineates a critical molecular axis in prostate cancer biology, connecting CREB5-regulated transcriptional programs with basal-like and stem cell-like tumor phenotypes. Its implications extend beyond fundamental cancer biology, offering a conceptual framework for combating therapy resistance and tumor progression via targeted disruption of transcription factor networks.

In conclusion, the elucidation of CREB5 as a master regulator of aggressive prostate cancer phenotypes underscores the complexity of tumor transcriptional landscapes and emphasizes the importance of transcriptional plasticity in cancer evolution. Through such insights, the cancer research community gains a new molecular target that may revolutionize therapeutic strategies for prostate cancer.

DOI: https://doi.org/10.18632/oncotarget.28826
Correspondence: Emmanuel S. Antonarakis – anton401@umn.edu, Justin Hwang – jhwang@umn.edu

Subject of Research: Cells
Article Title: CREB5 regulates stem cell-like transcriptional programs to enhance tumor progression in prostate cancer
News Publication Date: 17-Mar-2026
Web References: https://doi.org/10.18632/oncotarget.28826
Image Credits: © 2026 Makovec et al. Distributed under CC BY 4.0
Keywords: cancer, prostate cancer, CREB5, basal-like, stem cell-like, AP-1 transcription factors

A groundbreaking avenue in prostate cancer research centers around the pioneer transcription factor FOXA1. This factor, frequently mutated in prostate tumors—ranking as the third most mutated gene—plays an indispensable role in the initiation and progression of prostate malignancies. FOXA1’s regulatory function is largely contingent on post-translational modifications; however, the intricate details governing these modifications have remained elusive until now. Parallel to this, cyclin-dependent kinase 12 (CDK12), a kinase with recognized involvement in transcription elongation and DNA damage response, has emerged as a critical player in prostate cancer pathobiology. Genetic aberrations in CDK12 correlate strongly with disease progression and unfavorable prognosis.

Recent research has for the first time delineated a direct mechanistic link between CDK12 and FOXA1, unveiling a novel signaling axis integral to prostate tumor development. The study identifies CDK12 as a direct kinase for FOXA1, revealing a phosphorylation-dependent activation pathway that propels oncogenic processes. Central to this axis is the phosphorylation of FOXA1 at serine residue 234 (S234), a highly conserved amino acid within the DNA-binding domain of FOXA1, which modulates its transcriptional activity and downstream gene regulatory functions.

The identification of this site was accomplished through sophisticated bioinformatics analyses complemented by rigorous in vitro and in vivo validation experiments. The researchers engineered precise site-directed mutants of FOXA1—S234A to represent a non-phosphorylatable form, and S234E as a phosphomimetic version—thereby enabling detailed functional dissection of this modification. Crucially, the development of a novel, site-specific antibody against phosphorylated S234-FOXA1 furnished a powerful tool for probing the dynamics of this modification in cellular contexts.

Mechanistically, this phosphorylation event amplifies FOXA1’s chromatin binding affinity and transcriptional potency without altering its cellular localization. Functional genomics and reporter assays illuminated that phosphorylated FOXA1 directly upregulates MDM2, an E3 ubiquitin ligase that orchestrates the ubiquitination and subsequent proteasomal degradation of the tumor suppressor p53. By intensifying MDM2 transcription, phosphorylated FOXA1 effectively diminishes p53 protein stability, thereby suppressing apoptosis and fostering a cellular milieu conducive to cancer cell survival and unchecked proliferation.

The CDK12-FOXA1-MDM2-p53 signaling cascade represents a comprehensive oncogenic axis in prostate cancer. Disruption of this pathway, particularly at the level of CDK12 catalytic activity, emerges as a promising therapeutic intervention point. The study showcases that THZ531, a selective small molecule inhibitor of CDK12/13, robustly suppresses FOXA1 transcriptional activity and compromises tumor cell viability. Notably, in vivo experiments utilizing prostate cancer xenograft models in immunocompromised mice demonstrated that THZ531 administration significantly retards tumor growth, restores p53 protein levels by reducing MDM2 expression, and curtails malignant progression.

The implications of these findings extend beyond fundamental mechanistic insights. They offer a tangible strategy for tackling subsets of prostate cancer patients characterized by aberrant CDK12 activity or elevated FOXA1 expression. Targeting CDK12 with inhibitors such as THZ531 promises a dual-pronged therapeutic effect: attenuating FOXA1’s oncogenic transcriptional output alongside stabilizing p53, the guardian of the genome, effectively disrupting cancer-promoting signals from multiple angles.

Importantly, the phosphorylation-mediated regulation of FOXA1 outlined in this study enriches the understanding of post-translational modification networks that fine-tune transcription factor function in cancer. It also bridges the gap between FOXA1 and the classical MDM2-p53 tumor suppressor pathway, a relationship previously unrecognized in prostate oncogenesis. This discovery thus anchors FOXA1 not only as a pioneer factor for chromatin remodeling but also as a pivotal modulator of tumor suppressor homeostasis.

While this research solidifies the role of CDK12-driven FOXA1 phosphorylation in apoptosis inhibition and proliferation, it opens new avenues for investigating broader epigenomic ramifications. Future work is warranted to explore how S234 phosphorylation influences genome-wide chromatin plasticity, affects global gene expression patterns, and intersects with androgen receptor signaling pathways, which remain central to prostate cancer biology.

Moreover, clinical translation of these insightful findings is a high priority. Rigorous clinical trials assessing the safety, efficacy, and combinatorial potential of CDK12 inhibitors like THZ531 alongside established therapies—such as androgen deprivation and chemotherapy—will be essential. Such studies may pave the way for personalized medicine approaches that exploit the vulnerabilities of the CDK12-FOXA1-MDM2-p53 axis in treatment-resistant prostate cancers.

Overall, this research marks a significant leap forward in prostate cancer biology and therapeutic development. By illuminating a precise molecular mechanism that drives tumor progression, it provides a robust scientific foundation for new treatment paradigms aimed at improving the prognosis for patients facing advanced, refractory disease.

Subject of Research:
Not applicable

Article Title:
CDK12-Mediated Phosphorylation of FOXA1 Promotes Prostate Cancer Progression via the MDM2–p53 Axis

News Publication Date:
10-Nov-2025

Web References:
http://dx.doi.org/10.34133/research.0990

Keywords:
Prostate cancer, CDK12, FOXA1, phosphorylation, MDM2, p53, transcription factor, tumor progression, post-translational modification, kinase inhibitor, THZ531, apoptosis, chromatin binding