RESUMO
MicroRNA-375 (miR-375) is frequently elevated in prostate tumors and cell-free fractions of patient blood, but its role in genesis and progression of prostate cancer is poorly understood. In this study, we demonstrated that miR-375 is inversely correlated with epithelial-mesenchymal transition signatures (EMT) in clinical samples and can drive mesenchymal-epithelial transition (MET) in model systems. Indeed, miR-375 potently inhibited invasion and migration of multiple prostate cancer lines. The transcription factor YAP1 was found to be a direct target of miR-375 in prostate cancer. Knockdown of YAP1 phenocopied miR-375 overexpression, and overexpression of YAP1 rescued anti-invasive effects mediated by miR-375. Furthermore, transcription of the miR-375 gene was shown to be directly repressed by the EMT transcription factor, ZEB1. Analysis of multiple patient cohorts provided evidence for this ZEB1-miR-375-YAP1 regulatory circuit in clinical samples. Despite its anti-invasive and anti-EMT capacities, plasma miR-375 was found to be correlated with circulating tumor cells in men with metastatic disease. Collectively, this study provides new insight into the function of miR-375 in prostate cancer, and more broadly identifies a novel pathway controlling epithelial plasticity and tumor cell invasion in this disease.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Fosfoproteínas/genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Transdução de Sinais , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo , Regiões 3' não Traduzidas , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Biomarcadores , Linhagem Celular Tumoral , Epitélio/metabolismo , Epitélio/patologia , Expressão Gênica , Humanos , Masculino , Células Neoplásicas Circulantes/metabolismo , Células Neoplásicas Circulantes/patologia , Fenótipo , Fosfoproteínas/metabolismo , Neoplasias da Próstata/patologia , Proteínas Proto-Oncogênicas c-met/genética , Proteínas Proto-Oncogênicas c-met/metabolismo , Interferência de RNA , Fatores de Transcrição , Proteínas de Sinalização YAP , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genéticaRESUMO
Recent evidence has implicated the transmembrane co-receptor neuropilin-1 (NRP1) in cancer progression. Primarily known as a regulator of neuronal guidance and angiogenesis, NRP1 is also expressed in multiple human malignancies, where it promotes tumor angiogenesis. However, non-angiogenic roles of NRP1 in tumor progression remain poorly characterized. In this study, we define NRP1 as an androgen-repressed gene whose expression is elevated during the adaptation of prostate tumors to androgen-targeted therapies (ATTs), and subsequent progression to metastatic castration-resistant prostate cancer (mCRPC). Using short hairpin RNA (shRNA)-mediated suppression of NRP1, we demonstrate that NRP1 regulates the mesenchymal phenotype of mCRPC cell models and the invasive and metastatic dissemination of tumor cells in vivo. In patients, immunohistochemical staining of tissue microarrays and mRNA expression analyses revealed a positive association between NRP1 expression and increasing Gleason grade, pathological T score, positive lymph node status and primary therapy failure. Furthermore, multivariate analysis of several large clinical prostate cancer (PCa) cohorts identified NRP1 expression at radical prostatectomy as an independent prognostic biomarker of biochemical recurrence after radiation therapy, metastasis and cancer-specific mortality. This study identifies NRP1 for the first time as a novel androgen-suppressed gene upregulated during the adaptive response of prostate tumors to ATTs and a prognostic biomarker of clinical metastasis and lethal PCa.