Effects of Glutathione S-transferase Mu Family on the Malignant Phenotype and Chemo-sensitivity in Human Bladder Cancer Cells

• Main Authors: Yu-Chiao, Deng, 鄧羽喬
• Other Authors: Liu, Yi-Wen
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/qv6fs6

碩士 === 國立嘉義大學 === 微生物免疫與生物藥學系研究所 === 106 === Bladder cancer is one of the common cancer in urinary system. According to the report of National Cancer Institute, the estimated incidence of bladder cancer ranks 4th in 2018 in USA. Bladder cancer incidence and death is higher in men than in women. Though the mortality rate of bladder cancer is not high, the high recurrence rate is a big problem. Hence, many studies aim to find bladder tumor markers in early stage. GSTM superfamily is one of the common antioxidative enzymes, and it contains five subtype genes including M1 to M5. In the previous study, it is known that there is a higher incidence of bladder cancer in people without GSTM1 gene. Besides, a study demonstrates that GSTM2 could effectively compensate for the loss of GSTM1 under physiological conditions. In my study, GSTM family genes were overexpressed individually in bladder cancer cells with GSTM1-null genotype, and the correlation of GSTMs expression, malignant phenotype and chemo-sensitivity was analyzed. First, we transfected plasmids containing individual human GSTMs genes in bladder cancer cells by PolyJetTM, and analyzed the overexpression protein by western blot. All of the GSTMs were overexpressed in 5637 cells at 24h after transfection, and the GSTMs protein level gradually decreased after 48h. We also measured the GST activity using CDNB as a substrate. The results showed that overexpression of GSTMs genes increased the GST activity, and the GSH/GSSG ratio was changed in 5637 cells. On cell functional assay, we confirmed that the cell migration was enhanced when the GSTMs genes were overexpressed, and GSTM2 was the most significant. On MTT assay, we found GSTM5 overexpression decreased cell number 32 h after transfection. On chemo-sensitivity assay, the results showed that overexpression of GSTM4 significantly reduced the cytotoxicity of doxorubicin, but had no significant effect in cisplatin. In conclusion, it has been proved that overexpression of GSTMs genes increased GST enzyme activity, and also enhanced cell migration in 5637 cells. However, only GSTM4 overexpression inhibited doxorubicin-induced bladder cancer cell death.