Abstract: Objective The objective of this study was to investigate the clinical value of serum microRNA in predicting chemotherapy efficacy in patients with nasopharyngeal carcinoma.Methods A total of 187 patients with nasopharyngeal carcinoma who received cisplatin combined chemotherapy were enrolled in our hospital from January 2010 to December 2016,including 123 patients with chemotherapy sensitivity and 64 patients with chemotherapy resistance.The serum levels of miRNA before the initial chemotherapy were measured,the efficacy and predictive value of serum miRNA in nasopharyngeal carcinoma patients were evaluated using healthy subjects as controls.Results Serum level of miR-127 in nasopharyngeal carcinoma patients was significantly higher than that in healthy controls(4.3±1.6 vs. 1.4±0.5,P＜0.001).Serum level of miR-127 was significantly higher in chemotherapy-resistant patients than that in chemotherapy-sensitive patients(4.5±1.3 vs. 3.8±1.7,P＜0.001).The ROC curve showed that the predictive value of serum miR-127 for chemotherapy resistance in nasopharyngeal carcinoma patients was 0.702(P＜0.001),with the optimal cut-off value of 4.2,sensitivity of 82.3% and specificity of 76.3%.Compared with the chemotherapy-sensitive group,the proportion of patients with T_3-4,N3 and TNM Ⅲ~Ⅳ in the chemotherapy-resistant group was significantly increased(P＜0.01),and the proportion of miR-127≥4.2 was also increased(P＜0.001).Multivariate logistic regression analysis showed that TNM staging(OR=1.655,95% CI:1.142~2.584,P=0.016)and serum miR-127≥4.2(OR=2.231,95% CI:1.762~4.503,P=0.001)were independent risk factors affecting chemotherapy resistance in nasopharyngeal carcinoma patients.Conclusion The elevated serum level of miR-127 is an important risk factor for predicting chemotherapy resistance in patients with nasopharyngeal carcinoma.

Key words: Nasopharyngeal carcinoma, Chemotherapy resistance, microRNA