MicroRNA-129Expression And Its Clinical Significance In Advanced Gastric Cancer

Objective To explore microRNA-129(miRNA-129, miR-129) expression and itsclinical significance of in advanced gastric cancer. We will evaluate the effectiveness ofS-1/Oxaliplatin vs Doxifluridine/Oxaliplatin regimen and to identify miRNAs as potentialprognostic biomarkers in advanced gastric cancer patients.Methods Total RNAs were extracted from normal and gastric tumor FFPE specimens.The levels of miRNA-129expression was quantified using Real-time PCR analysis. Thecorrelation between the expression levels of miRNA-129with clinical characteristics wasanalyzed by using chi-square test. Overall survival (OS) in patients with clinicalpathological characteristics were analyzed using Kaplan-Meier and Log-rank test. The Coxproportional hazards model was performed to estimate Hazard risk (HR) with95%CI ofthe linking strength between the different clinical characteristics, expression ofmiRNA-129, and death risk.Results The expression levels of miRNA-129were significantly overexpressed ingastric tumors compared to normal gastric tissues (P<0.001). It was significantlycorrelation with previous treatment (P=0.014), no correlation with gender, age, stage,tumor size, histological type by using chi-square test. The second course therapeutic effectwas significantly correlated with OS (P=0.014). Kaplan-Meier survival analysis revealedthat the median survival time of patients after second course therapeutic effect with PR, SD,PD was8.41(5.29-11.52)、10.16(7.19-13.14) and5.10(3.11-7.08) months respectively. Thehigh level of miRNA-129expression was closely associated with poor overall survival(OS). The median OS of miRNA-129low expression patient subgroup was8.74(6.71-10.77) months. In contrast, OS was only6.27(5.17-7.37) months for the highexpression subgroup (P=0.026). The results of Cox model show that the HR of patientsafter second course therapeutic effect with SD, PD was0.95(95%CI：0.351-2.562，P=0.85)and6.02(95%CI：1.683-21.57，P=0.009) compared with PR patients. The median survival time of patients with low miRNA-129expression showed a significant increase than that ofthe high miRNA-129group,8.74(6.71-10.77) and6.27(5.17-7.37), respectively. The HRfor death of the high group was2.77times than the low group (95%CI:1.12-6.87，P=0.028).Conclusions Abnormal expression of miRNA-129has been implicated in gastriccancer, and the level expression of miRNA-129was closely associated with prognosis ofadvanced gastric cancer patients. miRNA-129holds great potential as a prognosticbiomarker and a valuable indicator of chemotherapy regimen in gastric cancer.