Expression and change of ERRα inoxaliplatin-resistant colon cancer cells after the downregulation of tetrasoanin

Abstract

Objective To observe the proliferation and apoptosis of oxaliplatin-resistant colon cancer cell lines and the expression of estrogen receptor related receptor (ERR)α when tetrasoanin was down-regulated. Methods Western blot and quantitative real-time polymerase chain reaction(qRT-PCR) were used to detect the expression of tetrasoanin and ERRα of colon cancer cells and oxaliplatin resistant cells in mRNA and protein levels. ERRα inhibitor XCT790 was used to down-regulate ERRα expression, The expression of ERRα was down regulated by ERR α inhibitor XCT790, and the level of tetrasoanin, apoptosis and proliferation of L-OHP-SW620 cells were detected by Western blot, flow cytometry and MTT.Tetrasoanin expression was down regulated by siRNA, the expression, apoptosis and proliferation of L-OHP-SW620 cells AKT, p-AKT, tetrasoanin and ERRα were detected by Western blot, qRT-PCR, flow cytometry and MTT assay. Results The expression of tetrasoanin and ERRα protein in L-OHP-SW620 cell lines were higher than those in SW620 cells (t=6.127, P<0.01, t=12.579, P<0.01), The expression of tetrasoanin mRNA in L-OHP-SW620 cell line was higher than that in SW620 cell line (t=9.085, P< 0.01). The early apoptosis rate of L-OHP-SW620 cells in XCT790 group after XCT790 inhibited ERR -αexpression was higher than that in NC group (t=3.297, P< 0.01). The survival rate of XCT790 group after 72 h culture was (45.264±6.249)%, lower than that of NC group ( (63.364±9.472)%) (t=4.537, P<0.01). Compared with NC group, p-AKT protein was up-regulated(t=8.139, P<0.01), ERRα protein was down-regulated(t=6.452, P<0.01), the apoptosis rate was(17.541±2.317)%, lower than that in the sitetrasoanin group ((32.892±3.296)%) (t=4.526, P<0.01), the survival in sitetrasoanin group after 72 h culture was (49.653±5.945)%, lower than that in NC group((67.376±7.934)%) (t=3.109, P<0.05). Conclusion Tetrasoanin down-regulation and p-AKT protein up-regulation decreases ERRα protein and OHP-resistant colon cell proliferation is decreased, apoptosis is increased and drug resistance is decreased. Key words: Tetrasoanin; Chemo-resistant; Colon cancer; Small interfere RNA