Project description:Neuroendocrine prostate cancer is an aggressive disease characterized by early metastasis, drug resistance and poor prognosis. Genome-wide association studies (GWAS) previously identified numerous single nucleotide polymorphisms (SNPs) associated with prostate cancer. SNP rs11067228 as a significant variant associated with castration-resistant metastasis (CM) in prostate cancer (PCa). However, mechanisms underlying activity of the rs11067228 risk variant remain unclear. Here, we demonstrated that risk SNP rs11067228 is located in an H3K27ac-enriched active enhancer, and that activity of that region affects castration-resistance and neuroendocrine differentiation in PCa cells. We identified the RNA-splicing factor SRRM4 as a functional target gene as shown in both cell line and xenograft model. In addition, overexpression of SRRM4 is sufficient to induce PCa cell drug resistance and neuroendocrine differentiation. Moreover, site-directed mutation of the rs11067228 non-risk G to the risk A allele enabled binding of the transcription factor SOX4, activating candidate target gene expression. Taken together, our findings indicated that the rs11067228-associated enhancer modulates expression of SRRM4 via allele-specific long-range chromatin interactions, thereby governing PCa drug resistance and neuroendocrine differentiation.
Project description:Prostate cancer relapsing from antiandrogen therapies can exhibit variant histology with altered lineage marker expression, suggesting lineage plasticity facilitates therapeutic resistance. Mechanisms underlying prostate cancer lineage plasticity are unknown, and relevant experimental models are needed. We demonstrate Rb1 loss facilitates lineage plasticity and metastasis of prostate adenocarcinoma initiated by Pten mutation in the mouse. Additional loss of Trp53 causes resistance to antiandrogen therapy. Gene expression profiling indicates mouse tumors are comparable to human prostate cancer neuroendocrine variants; both mouse and human tumors exhibit increased expression of epigenetic reprogramming factors like Ezh2 and Sox2. Clinically relevant Ezh2 inhibitors restore androgen receptor expression and sensitivity to antiandrogen therapy. These findings uncover genetic mutations enabling prostate cancer progression, identify mouse models for studying prostate cancer lineage plasticity, and suggest an epigenetic approach for extending clinical responses to antiandrogen therapy.
Project description:Prostate adenocarcinoma (AdPC) cells can undergo lineage switching to neuroendocrine cells and develop into therapy-resistant neuroendocrine prostate cancer (NEPC). While genomic/epigenetic alterations are shown to induce neuroendocrine differentiation via an intermediate stem-like state, RNA splicing factor SRRM4 can transform AdPC cells into NEPC xenografts through a direct neuroendocrine transdifferentiation mechanism. Whether SRRM4 can also regulate a stem-cell gene network for NEPC development remains unclear. Here, we use the Ion AmpliSeqTM Transcriptome Human Gene Expression Kit (AmpliSeq) to analyze the transcriptome of human AdPC cell line DU145 overexpressing SRRM4 via lentiviral transduction compared to the control, empty vector-transduced DU145 cells. This study reveals that SRRM4 induces a pluripotency gene network consisting of the stem-cell differentiation gene, SOX2. In summary, we report a novel mechanism by which SRRM4 drives NEPC progression via a pluripotency gene network.
Project description:Neuroendocrine prostate cancer (NEPC) is a lethal subtype of castration-resistant prostate cancer (CRPC). The molecular mechanisms underlying the progression of CRPC toward NEPC remain incompletely understood and effective treatments remain to be discovered. Herein, we report that loss of the nuclear receptor ERRγ promotes neuroendocrine differentiation in a Pten-deficient mouse model of prostate adenocarcinoma. These findings were recapitulated in advanced cellular and xenograft models of human prostate cancer (PCa). Critically, we show that ERRγ gain-of-function can reverse instilled NEPC features accompanied by suppression of growth and oncogenic metabolic reprogramming. Activation of a neuroendocrine transcriptional program enabled by ERRγ deficiency unveiled a targetable vulnerability exploited by combined pharmacological inhibition of EZH2 and RET kinase that effectively inhibited the growth of ERRγ-deficient tumor organoids and cells. Collectively, our findings demonstrate that ERRγ downregulation facilitates PCa adeno-to-neuroendocrine transformation and offer potential therapeutic strategies to prevent/treat the development of poor outcome NEPC.
Project description:Neuroendocrine prostate cancer (NEPC) is a lethal subtype of castration-resistant prostate cancer (CRPC). The molecular mechanisms underlying the progression of CRPC toward NEPC remain incompletely understood and effective treatments remain to be discovered. Herein, we report that loss of the nuclear receptor ERRγ promotes neuroendocrine differentiation in a Pten-deficient mouse model of prostate adenocarcinoma. These findings were recapitulated in advanced cellular and xenograft models of human prostate cancer (PCa). Critically, we show that ERRγ gain-of-function can reverse instilled NEPC features accompanied by suppression of growth and oncogenic metabolic reprogramming. Activation of a neuroendocrine transcriptional program enabled by ERRγ deficiency unveiled a targetable vulnerability exploited by combined pharmacological inhibition of EZH2 and RET kinase that effectively inhibited the growth of ERRγ-deficient tumor organoids and cells. Collectively, our findings demonstrate that ERRγ downregulation facilitates PCa adeno-to-neuroendocrine transformation and offer potential therapeutic strategies to prevent/treat the development of poor outcome NEPC.