Project description:Neuroendocrine prostate cancer (NEPC) is a highly aggressive malignancy of increasing prevalence with an unmet need for targeted therapeutic approaches. The oncogenic MUC1-C protein is overexpressed in castration-resistant prostate cancer (CRPC) and NEPC; however, there is no known role for MUC1-C in driving lineage plasticity to these advanced PC phenotypes. The present studies demonstrate that upregulation of MUC1-C in androgen-independent (AI) PC cells suppresses androgen receptor (AR) axis signaling and induces the neural BRN2 transcription factor by a previously unrecognized MYC-mediated mechanism. MUC1-C activates the BRN2 pathway in association with induction of MYCN, EZH2 and NE differentiation markers (ASCL1, AURKA and SYP), which are linked to NEPC progression. We also show that MUC1-C suppresses the p53 pathway, induces the Yamanaka pluripotency factors (OCT4, SOX2, KLF4 and MYC) and drives stemness. Of potential clinical relevance, targeting MUC1-C decreases PC self-renewal capacity and tumorigenicity, supporting the treatment of CRPC and NEPC with agents directed against this oncoprotein. These findings and the demonstration that MUC1-C is upregulated and associated with suppression of AR signaling, and increases in BRN2 expression and the NEPC score in PC tissues highlight the unanticipated importance of MUC1-C as a master effector of lineage plasticity in progression to advanced PC with NE features.
Project description:Patients with rare pancreatic neuroendocrine tumors (pNETs) have limited access to effective targeted agents and invariably succumb to progressive disease. MUC1-C is a druggable oncogenic protein linked to driving pan-cancers. There is no known involvement of MUC1-C in pNET progression. The present work was performed to determine if MUC1-C represents a potential target for advancing pNET treatment. We demonstrate that the MUC1 gene is upregulated in primary pNETs that progress with metastatic disease. In pNET cells, MUC1-C drives E2F- and MYC-signaling pathways necessary for survival. Targeting MUC1-C genetically and pharmacologically also inhibits self-renewal capacity and tumorigenicity. Studies of primary pNET tissues further demonstrate that MUC1-C expression associates with (i) advanced NET grade and pathological stage, (ii) metastatic disease, and (iii) decreased disease-free survival. These findings demonstrate that MUC1-C is necessary for pNET progression and is a novel target for treating these rare cancers with anti-MUC1-C agents under clinical development.
Project description:The aberrant overexpression of mucin 1 (MUC1) and human epidermal growth factor receptor 2 (HER2) are often observed in breast cancer. However, the role of concomitant of MUC1/HERR2 in the development of breast cancer has not been fully illustrated. Following analysis public microarray datasets that revealed a correlation of double positive of MUC1 and HER2 to a worse clinical outcome, we generated a mouse model overexpressing both Her2 and MUC1 cytoplasmic domain (MUC1-CD) to investigate their interaction in mammary carcinogenesis. Coexpression of Her2 and MUC1-CD confers growth advantage and promotes the development of spontaneous mammary tumors. Genomic analysis uncovers that enforced expression of MUC1-CD and Her2 induces mammary tumor lineage plasticity which is supported by gene reprogramming and mammary stem cell enrichment. With gain- and loss-of function strategies, we show that coexpression of Her2 and MUC1-CD was associated with down-regulation of TCA cycle genes in tumors. Importantly, the reduction of TCA cycle genes induced by MUC1-CD is is significantly connected to the poor prognosis in HER2+ breast cancer patients. In addition, MUC1 augments Her2 signaling pathway by inducing Her2/Egfr dimerization. These findings collectively demonstrate the vital role of MUC1-CD/Her2 collaboration in shaping mammary tumor landscape and highlight the prognostic and therapeutic implication of MUC1 in patients with Her2+ breast cancer.
Project description:Small cell lung cancer (SCLC) is a recalcitrant malignancy associated with dysregulation of MYC signaling and the CDK-RB-E2F axis. We report that expression of the oncogenic MUC1-C protein in SCLC cells integrates activation of MYC and the E2F pathway. MUC1-C drives MYC and E2F target genes and regulates the G2/M checkpoint, mitotic spindle pathway and replication stress response (RSR). We further show that MUC1-C MYC signaling (i) induces NOTCH2, a marker of pulmonary neuroendocrine (NE) stem cells that are the proposed cell of SCLC origin, (ii) drives NE differentiation, as evidenced by expression of ASCL1 and POU3F2/BRN2, and (iii) promotes self-renewal capacity and tumorigenicity of SCLC cells. Analyses of datasets from SCLC tumors confirmed that MUC1 significantly associates with the MYC pathway. These findings uncover a master role for MUC1-C in promoting progression of the SCLC stem cell state and support MUC1-C as a potential target for SCLC treatment.
Project description:Small cell lung cancer (SCLC) is a recalcitrant malignancy associated with dysregulation of MYC signaling and the CDK-RB-E2F axis. We report that expression of the oncogenic MUC1-C protein in SCLC cells integrates activation of MYC and the E2F pathway. MUC1-C drives MYC and E2F target genes and regulates the G2/M checkpoint, mitotic spindle pathway and replication stress response (RSR). We further show that MUC1-C MYC signaling (i) induces NOTCH2, a marker of pulmonary neuroendocrine (NE) stem cells that are the proposed cell of SCLC origin, (ii) drives NE differentiation, as evidenced by expression of ASCL1 and POU3F2/BRN2, and (iii) promotes self-renewal capacity and tumorigenicity of SCLC cells. Analyses of datasets from SCLC tumors confirmed that MUC1 significantly associates with the MYC pathway. These findings uncover a master role for MUC1-C in promoting progression of the SCLC stem cell state and support MUC1-C as a potential target for SCLC treatment.
Project description:Neuroendocrine prostate cancer (NEPC) is an aggressive malignancy with no effective targeted therapies. The oncogenic MUC1-C protein is overexpressed in castration-resistant prostate cancer (CRPC) and NEPC, but its specific role is unknown. Here, we demonstrate that upregulation of MUC1-C in androgen-dependent PC cells suppresses androgen receptor (AR) axis signaling and induces the neural BRN2 transcription factor. MUC1-C activates a MYC→BRN2 pathway in association with induction of MYCN, EZH2 and NE differentiation markers (ASCL1, AURKA and SYP) linked to NEPC progression. Moreover, MUC1-C suppresses the p53 pathway, induces the Yamanaka pluripotency factors (OCT4, SOX2, KLF4 and MYC) and drives stemness. Targeting MUC1-C decreases PC self-renewal capacity and tumorigenicity, suggesting a potential therapeutic approach for CRPC and NEPC. In PC tissues, MUC1 expression associates with suppression of AR signaling and increases in BRN2 expression and NEPC score. These results highlight MUC1-C as a master effector of lineage plasticity driving progression to NEPC.
Project description:Treatment-induced neuroendocrine prostate cancer (t-NEPC) is a lethal subtype of castration-resistant prostate cancer resistant to androgen receptor (AR) inhibitors. Our study unveils that AR suppresses neuronal development protein dihydropyrimidinase-related protein 5 (DPYSL5), providing a mechanism for neuroendocrine transformation under androgen deprivation therapy. Our unique CRPC-NEPC cohort with 157 patient samples, including 55 t-NEPC patient samples, shows a high expression of DPYSL5 in t-NEPC patients, and that DPYSL5 correlates with neuroendocrine markers and inversely with AR and PSA. DPYSL5 overexpression in prostate cancer cells induces neuron like phenotype, enhances invasion, proliferation, and upregulates stemness and neuroendocrine related markers. Mechanistically, DPYSL5 promotes prostate cancer cell plasticity via EZH2-mediated PRC2 activation. Depletion of DPYSL5 halts proliferation, induces G1 phase cell cycle arrest, reverses neuroendocrine phenotype and upregulates luminal genes. In conclusion, DPYSL5 plays a critical role in regulating prostate cancer cell plasticity, and we propose the AR/DPYSL5/EZH2/PRC2 axis as a novel driver of t-NEPC progression.