Analysis of the Effect of Ubiquitin Deficiency on Malignant Cancer Cells

• Main Authors: Chih-WeiHuang, 黃智偉
• Other Authors: Wen-Tsan Chang
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/91946226808799867095

碩士 === 國立成功大學 === 生物化學暨分子生物學研究所 === 103 === Ubiquitin is a small protein that has involved in almost all eukaryotic organisms and it is highly conserved. It consists of 76 amino acids and has a molecular mass of about 8.5 kDa. The function of ubiquitin is to specifically target the proteins that need to be degraded. Recent studies show that many types of cancer present the high level of ubiquitin, which promotes cancer cell migration and tumor growth as compared with the normal cell. To approach more detail results, I have established a stable knockdown ubiquitin in four different malignant cancer cells, including HeLa, H1299, MDA-MB-231 and PC3 by applying the RNAi technique. Analysis of the knockdown cell line shows that loss of ubiquitin expression would decreased the cell growth, migration, colony formation ability and colony numbers. Moreover, to understand the drug sensitivity between the stable knockdown cell lines and control cell lines, I use 2-Deoxy-D-glucose, metformin and etoposide to examine the difference. The result shows that stable knockdown cell lines have a higher drug sensitivity and have the dosage effect. Beside these results, flow cytomertry assays show that loss of ubiquitin casues the change of cell cycle distribution and a higher amount of G2/M phase. Furthermore, western blot assays also demonstrate that many cyclin proteins such as cdc2 and cyclinB1 are downregulated. Taken together, the ubiquitin deficiency on malignant cancer cell may be potential anti-tumor treatment in the future.