Understanding Cellular Dependencies in Prostate Cancer

Scientists have found that prostate cancer cells depend heavily on two small enzymes that act like behind the-scenes stabilizers. These enzymes, called PDIA1 and PDIA5, help the cancer keep its main growth signal steady, almost like holding up the frame of a tent. When researchers blocked these enzymes in lab studies and preclinical models, the entire structure supporting the cancer’s growth signal fell apart. Without that support, the cells could no longer keep themselves organized, and they began to break down. This surprising weakness shows that prostate cancer relies on a hidden support system rather than just one obvious driver. The team also discovered that shutting off these enzymes affects more than the cancer’s growth signal. It disrupts the cell’s internal energy supply, damaging the structures that normally produce fuel and manage stress. When those power sources falter, the cells lose their ability to recover, making them even more vulnerable. This two-sided hit helps explain why blocking PDIA1 and PDIA5 had such a dramatic effect in the experiments. In preclinical tests, combining enzyme-blocking compounds with an existing prostate cancer drug made the treatment noticeably stronger. The drug worked better because the cancer no longer had backup systems to protect itself. These findings suggest a promising direction for designing future treatments that can take advantage of this built-in weakness and make resistant tumors easier to target. Research Paper 📄 DOI: 10.1073/pnas.2509222122

Identifying drivers of cancer progression to guide treatment selection is hindered by our limited understanding of tumor heterogeneity and its impact on tumor evolution. Here, we delineate the phenotypic variability across ~300,000 cells collected from multiple tumor loci in primary prostate and matched locoregional metastases using single-cell chromatin accessibility and gene expression sequencing. We find inter-patient heterogeneity to be confined to malignant populations. Within individual tumor loci, we see phenotypic heterogeneity among malignant cell populations despite a shared clonal genotypic architecture. We also observe that malignant cell populations disseminating to locoregional lymph nodes mirror the clonal architecture and phenotypic heterogeneity across primary tumor loci, while shifting from canonical prostate-cancer states to non-canonical inflammatory-like states. Our findings suggest a bottleneck imposed during the dissemination process, funneling prostate cancer cells toward an inflammatory-like cell state. These insights into the interplay between phenotypic identity and clonal architecture refine our understanding of prostate cancer progression and suggest that convergence of cancer cells towards an inflammatory-like state underlies dissemination to lymph nodes, offering a critical framework for future studies into prostate cancer metastatic potential. Paper and research by Tina Keshavarzian and larger team

Cracking the code for prostate cancer. A large team of researchers led by Wouter Karthaus, head of Endocrine Therapy Resistance and Molecular Genetics Lab at EPFL, and Eneda Toska, head of Toska Lab and Assistant Professor of Oncology Johns Hopkins University identified the enzyme KMT2D as a key epigenetic regulator in prostate cancer. Study reveals KMT2D plays a central role in shaping how prostate tumors grow, survive, and respond to therapy. Additional contributors listed below. 07 Jan 2026 Excerpt: Most prostate cancers rely on the androgen receptor to fuel growth. These tumors are typically treated with hormone-based therapies that block androgen receptor signaling. Over time, many prostate cancers adapt and become resistant tumors that give rise to “castration-resistant prostate cancers” (CRPC). Some CPRCs continue to depend on androgen receptors, but others shift away altogether, becoming harder to treat. Note: Researchers discovered KMT2D enzyme makes it easier for the androgen receptor to reach and switch on key genes involved in tumor growth, by altering the structure of chromatin, a dense protein packaging of DNA in the cell. As a result, androgen receptor and helper proteins can access their target sites more effectively. This helps maintain the activity of androgen receptor-driven prostate cancers, which depend on this pathway to proliferate. The study also found KMT2D also plays a vital role in an aggressive form of androgen receptor-independent CRPC known as the “stem cell-like” subtype. In these tumors, KMT2D sustains a hybrid cellular identity by regulating a different set of transcription factors, notably in the AP-1 family such as FOSL1, linked to stem-like behavior and therapy resistance. The new findings were identified using genetically engineered prostate cancer cell lines, and organoids derived from patients, single-cell sequencing, and animal models. Removing or silencing KMT2D disrupted the cancer cells’ ability to maintain their identities and made them more vulnerable to treatments. Key: In preclinical models, blocking KMT2D amplified the effectiveness of certain anti-cancer drugs (PI3K/AKT inhibitors and adenosine receptor inhibitors). The findings suggest KMT2D could be a valuable therapeutic target in prostate cancer. Disabling it could re-sensitize tumors to existing therapies or slow progression into more aggressive forms. The work also reinforces the importance of tailoring treatments to specific tumor subtypes, and of using epigenetic profiling to guide therapy decisions. Additional information and link to published research enclosed. https://lnkd.in/e3BvGcaR

Prostate cancer cells with low levels of PKCλ/ι (turquoise) show increased EZH2 expression (magenta) #Prostate_cancer is a leading cause of cancer-related death in men, claiming over 30,000 lives annually in the United States. While most prostate cancers initially respond to androgen receptor-blocking therapies, some tumors evolve into a highly aggressive, treatment-resistant form known as neuroendocrine prostate cancer, which no longer relies on androgen signaling and is therefore difficult to treat. Understanding this transition has become a priority for researchers and clinicians. An enzyme called EZH2 has an unexpected role in driving aggressive tumor growth in treatment-resistant prostate cancers, according to a new study by scientists at Weill Cornell Medicine. Normally, PKCλ/ι limits EZH2's activity. However, in PKCλ/ι-deficient cells treated with androgen receptor inhibitors, an alternative form of EZH2 is produced that has a different function. Instead of repressing tumor-suppressor genes, this form of EZH2 drives rapid protein production and activates growth factors like TGF-β, fostering an environment around the tumor that promotes cancer progression despite androgen receptor inhibition. In preclinical studies, the team targeted EZH2's alternative activities to assess potential treatment solutions. They found that inhibiting either protein synthesis or the TGF-β pathway effectively reversed resistance in PKCλ/ι-deficient cancer cells. Blocking EZH2's alternative function restored sensitivity to androgen receptor therapies like enzalutamide. Furthermore, since TGF-β is associated with immune suppression in tumors, inhibiting this pathway could enhance #immunotherapy effectiveness, a treatment with limited success against prostate cancer alone. The researchers noted that the absence of PKCλ/ι creates a unique vulnerability in #cancer cells, suggesting that combining EZH2 inhibitors with AR-targeted therapies could significantly inhibit tumor growth. REF: https://lnkd.in/dTbm2X7X

Researchers have identified the enzyme PI5P4Kα as a central energy regulator that prostate cancer cells depend on to survive. By blocking this enzyme scientists were able to shut down critical metabolic pathways causing tumor cells to lose their energy supply and self destruct. Unlike chemotherapy or radiation this strategy selectively targets cancer metabolism while leaving healthy tissue unharmed. Laboratory and animal studies showed complete tumor regression with no detectable toxicity highlighting its precision. With preparations underway for human clinical trials this discovery could mark a turning point in prostate cancer treatment. It may also provide a blueprint for targeting metabolic vulnerabilities across multiple cancers. Source Science PMID 23599263