The role of GIT1 in cell proliferation and motility of HeLa cells.

• Main Authors: Yung-JuWang, 王詠茹
• Other Authors: Tzeng-Horng Leu
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/40548107016435514503

碩士 === 國立成功大學 === 藥理學研究所 === 98 === GIT1 (G protein-coupled receptor kinase-interacting protein 1) is a multidomain protein involved in diverse cellular processes. GIT1 is identified as an ADP ribosylation factor GTPase-activating protein (ARF-GAP) that binds G protein-coupled receptor kinases (GRKs) and regulates membrane trafficking. By interacting with various signaling molecules, such as paxillin, focal adhesion kinase (FAK), Src and mitogen-activated protein kinase kinase 1 (MEK1), GIT1 modulates focal adhesion turnover and mobility in normal cells. Since FAK and Src could mediate both cell migration and proliferation in cancer cells, we wonder whether GIT1 may also participate in these processes. At first, we confirm the protein expression of GIT1 in several cancer cell lines, including HeLa cells and SW620 cells. HeLa cells express ample GIT1. By transient transfection of git1 siRNA in HeLa cells, we observe that GIT1 knockdown reduces expression of FAK. This FAK reduction is not due to the reduction of RNA transcript, but rather by decreasing FAK protein stability. MTT assay and cell culture in soft agar separately show that GIT1 knockdown inhibits anchorage-dependent and -independent cell growth. In addition, GIT1 knockdown inhibits cell migration. Cell migration is a dynamic process that requires the coordinated formation and disassembly of focal adhesions. Immunofluorescence microscopy shows that GIT1 knockdown reduces focal adhesion formation. This result indicates that GIT1 may affect cell migration via facilitate the formation of focal adhesion. Our results indicate that GIT1 participates in HeLa cell proliferation and migration, suggesting it may be an important anticancer drug target.