Expression of glyoxalase Ⅰ and its effect on cell proliferation and apoptosis in endometrial carcinoma

Objective To examine the expressions of glyoxalase Ⅰ (GLO-Ⅰ ) in endometrial cancer tissues and cell lines and to investigate the roles of GLO-Ⅰ on proliferation and apoptosis in endometrial cancer cells. Methods Immunohistochemistry, western blot and RT-PCR were used to investigate the expressions of GLO-Ⅰ protein and mRNA in endometrial cancer tissues and Ishikawa cell lines ;enzyme activity of GLO-Ⅰ in normal endometrium, endometrial cancer and paraneoplastic tissue samples was detected with spectrophotometer; proliferation and apoptosis of Ishikawa cell before and after RNA interference (RNAi) procedure were detected by the methyl thiazolyl tetrazolium (MTT) and flow cytometry, respectively. Results (1)There were significant differences of GLO-Ⅰ expression between normal endometrium (0/19) and endometrial cancer tissues ( 76%, 22/29 ); these were also significant differences of enzyme activity of GLO-Ⅰ among normal endometrium, paraneoplastic and endometrial cancer tissues( 1.1,0.8 vs 92.3 IU/mg; P <0.01 ). Enzyme activity of GLO-Ⅰ in fresh normal endometrium and paraneoplastic tissues was weak, while that of fresh endometrial cancer tissues was as high as 92. 3 IU/mg in average. (2)The expression of GLO-Ⅰ mRNA in Ishikawa cell transfected with GLO-Ⅰ siRNA was significantly lower than that in negative group (0.25 ± 0.06 vs 0.93 ± 0.10, P < 0.0l ), and the similar results that in the expression of GLO-Ⅰ protein (0.38 ±0.06 vs 0.94 ±0.13, P <0.01 ). (3) Proliferation in Ishikawa cell was significantly inhibited after silencing RNA expression of GLO-Ⅰ ( P = 0.028 ). The apoptosis rate of cells transfected with GLO- Ⅰ siRNA was significantly higher than that of negative control group and blank control group [ ( 6.7 ± 0.8 ) % vs ( 1.2 ± 0.4) %, ( 1.4 ± 0.4 ) %; P < 0.01 ]. Conclusion The expression and enzyme activity of GLO- Ⅰ is significantly increased in endometrial cancer, which could promote abnormal proliferation and inhibit apoptosis in endometrial cancer cells.