Objective To research the expression of X-linked inhibitor of apoptosis protein gene （XIAP） on paclitaxel resistance in ovarian cancer. Methods A2780 and A2780/T cells were treated with paclitaxel respectively at the concentrations of 5 ng/mL, 10 ng/mL, 20 ng/mL ,40 ng/mL, 80 ng/mL, 160 ng/mL, 320 ng/mL, then the inhibition rate of cells were detected by MTT assay. The expression of XIAP mRNA and protein among the A2780 and A2780/T cells treated respectively with paclitaxel at the concentration of 100 ng/mL was detected by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and Western blot. The A2780/T cells were divided into blank group, empty group, small interfering RNA (siRNA) XIAP group and siRNA-non-specific group. The expression of XIAP mRNA and protein of four groups were detected by RT-qPCR and Western blot. Apoptotic rate of these groups with addition of paclitaxel at the concentrations of 0 ng/mL, 1 000 ng/mL, 1 500 ng/mL, 2 000 ng/mL and 2 500 ng/mL were detected by flow cytometry. Results After the treatments on A2780 and A2780/T cells with the different concentrations of paclitaxel, the inhibition rate of A2780 cells were gradually increased with the increased paclitaxel concentrations (P<0.05), while there were no obvious differences in A2780/T cells (P>0.05). After the treatment on these cells with paclitaxel at the concentration of 100 ng/mL, the expression of XIAP mRNA was lower than that non-treatment with paclitaxelin A2780 cells (P<0.05), and the expression of XIAP mRNA in the A2780/T cells were no statistical significance between the treatment group and non-treatment group with paclitaxel (P>0.05). However, the expression of A2780/T cells’XIAP mRNA and protein treated with paclitaxel were higher than A2780 cells’ (P<0.05). The expression of XIAP mRNA and protein in siRNA-XIAP group was lower than those of other groups (P<0.05). The apoptotic rateof siRNA-XIAP group was higher than those of other groups treated with the paclitaxel at concentrations of 2 000 ng/mL and 2 500 ng/mL (P<0.05). Conclusion XIAP’s high expression on mRNA and protein was correlated with ovarian cancer paclitaxel-resistance, specific siRNA can promote cell apoptosis by reducing the expression of XIAP, and increase the sensitivity of drug-resistant cancer cells to paclitaxel.
