Multidrug resistance (MDR) is the main cause of tumor chemotherapy failure . This study aims to explore the influence of MDR1 methylation on curative effect of transcatheter arterial chemoembolization for cervical cancer.

67 patients with cervical cancer underwent transcatheter arterial chemoembolization were selected, and 45 cases of normal cervical tissues were included as a control group. Immunohistochemistry was used to detect the level of P-glycoprotein (P-gp) in cervical cancer, and compared with normal tissues. The methylation status of the MDR1 gene promoter region 16 CpG units was analyzed by using kilobase-specific cracking and matrix-assisted laser desorption ionization time of flight mass spectrometry.

The results indicated that the positive expression rates of P-gp were 0% (0/45) in normal cervical tissue, and 61.19% (41/67) and 77.61% (52/67) before and after transcatheter arterial chemoembolization in cervical cancer tissues, respectively. There were significant differences between cervical cancer tissues and normal cervical tissues (χ²=4.2523, 0.0392). The positive expression rate of P-gp before chemotherapy was negatively correlated with efficacy of chemotherapy (r=-0.340, P=0.005). Methylation rate of 13 CpG units in normal tissues was significantly greater than that in cervical tissues (P<0.05). In cervical cancer tissue, methylation rate of six CpG units before transcatheter arterial chemoembolization was higher than that after chemotherapy, but one CpG unit was lower than that after chemotherapy (P<0.05). The methylation rate of one CpG unit with effective chemotherapy before chemotherapy was significantly higher than ineffective chemotherapy (P<0.05), and the other CpG units were similar (P<0.05).

P-gp expression level coded by MDR1, methylation status of partial MDR1 gene promoter regions CpG island, is closely related to the efficacy of transcatheter arterial chemoembolization for cervical cancer.