Identification of Critical Protein Targets Involved in Prostate Cancer Metastatic Progression

• Main Authors: Wei-Ting Yang, 楊威霆
• Other Authors: Ming-Shyue Lee
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/g7754d

碩士 === 國立臺灣大學 === 生物化學暨分子生物學研究所 === 105 === Prostate cancer (PCa) is the second most common cancer among men worldwide. In Taiwan, PCa is the sixth cause of cancer-related mortality. In fact, metastasis contributes to most PCa casualties. Therefore, understanding the molecular mechanisms behind PCa metastasis is important for identifying novel biomarkers as well as developing new therapeutic approaches. In order to identify important factors regulating PCa metastasis, we applied a CWR22Rv1-M4 PCa metastatic progression model for the study. In this study, I showed that M4 cells had increased cell motility and anchorage-independent growth capacity when compared with parental CWR22Rv1 cells. Meanwhile, many genes with differential expressions between CWR22Rv1 and M4 cells were identified via next-generation sequencing (NGS) approach. We focused on genes functioning around pericellular surface, including EPHA7, CASP4, MMP14, PAI3, PN1, PRSS8, DPP4, PRSS21 and PRSS23. The differential expressions of the above genes were further validated with q-RT-PCR. Seven genes with significantly higher expressions in metastatic M4 cells were EPHA7, CASP4, MMP14, PAI3, PN1, PRSS8 and DPP4, while two genes with significantly lower expressions in M4 cells were PRSS21 and PRSS23. Three genes were excluded from my study after literature mining (EPHA7 and PN1) or western blot analysis (PRSS21). To explore if the rest of the genes participate in PCa metastatic progression, I applied short hairpin (sh) RNA knockdown approaches and found that PAI3 and PRSS23 had no significant impacts on PCa cell migration and invasion, suggesting that these two genes were not involved in the regulation of PCa cell motility. Knockdown of MMP14 decreased M4 cell migration and invasion, while DPP4 knockdown resulted in enhanced M4 cell motility. Furthermore, inhibiting DPP4 enzymatic activity with competitive inhibitor Diprotin A suppressed M4 cell motility. Interestingly, knockdown of DPP4 resulted in decreased anchorage-independent growth of M4 cells, whereas knockdown of PRSS23 in CWR22Rv1 cells resulted in decreased clonogenic and anchorage-independent growth. These results provided insights into potential involvements of these proteins in PCa metastatic progression.