The Roles of PCTK1 in Protein Secretion and Cancer Development

• Main Authors: Ren Jie Tan, 陳仁覺
• Other Authors: C. C. Chiou
• Format: Others
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/33886811852414536693

碩士 === 長庚大學 === 醫學生物技術暨檢驗學系 === 100 === PCTK1 gene is a member of the cyclin-dependent kinase (cdk) family; however, in stead of playing a role in cell cycle regulation, PCTK1 gene is involved in the process of exocytosis, especially in vesicular transport. Our previous study have revealed that PCTK1 protein was overexpressed in cancer cells, indicating a possible role of PCTK1 in cancer development. We hypothesize that PCTK1 regulates autocrine and paracrine secretion mechanisms and influence growth factor-independent proliferations of tumor cells. The aim of this study is to clarify whether PCTK1 promotes cancer growth or development through influencing secretory pathways. We select TSGH (a gastric cancer cell line) as the model cell line as it posses the ability of growth factor-independent proliferation and has high level of PCTK1 protein expression. A PCTK1-knockdown clone was established from TSGH cell by transfection with a plasmid containing PCTK1 shRNA. The amount and pattern of secretory proteins were investigated by centrifugal concentration and silver staining. The amount of total protein in conditioned media had no significant difference between the parental and the PCTK1-knockdown cells, but the patterns of secretion proteins were slightly different. Through MASS analysis and Western blotting, we identified β-actin as one of the secretory proteins affected by PCTK1. However, its physiological function remains unknown. In conclusion, we found that knockdown of PCTK1 could affect the pattern of secretory proteins in TSGH cells; and that β-actin is one of the secretary proteins regulated by PCTK1. The function of secreted β-actin needs further investigation.