Association of miR-193b Down-regulation and miR-196a up-Regulation with Clinicopathological Features and Prognosis in Gastric Cancer

Dysregulated expression of microRNAs (miRNAs) has been shown to be closely associated with tumordevelopment, progression, and carcinogenesis. However, their clinical implications for gastric cancer remainelusive. To investigate the hypothesis that genome-wide alternations of miRNAs differentiate gastric cancer tissuesfrom those matched adjacent non-tumor tissues (ANTTs), miRNA arrays were employed to examine miRNAexpression profiles for the 5-pair discovery stage, and the quantitative real-time polymerase chain reaction (qRTPCR)was applied to validate candidate miRNAs for 48-pair validation stage. Furthermore, the relationshipbetween altered miRNA and clinicopathological features and prognosis of gastric cancer was explored. Amonga total of 1,146 miRNAs analyzed, 16 miRNAs were found to be significantly different expressed in tissues fromgastric cancer compared to ANTTs (p<0.05). qRT-PCR further confirmed the variation in expression of miR-193band miR-196a in the validation stage. Down-expression of miR-193b was significantly correlated with Laurentype, differentiation, UICC stage, invasion, and metastasis of gastric cancer (p<0.05), while over-expression ofmiR-196a was significantly associated with poor differentiation (p=0.022). Moreover, binary logistic regressionanalysis demonstrated that the UICC stage was a significant risk factor for down-expression of miR-193b (adjustedOR=8.69; 95%CI=1.06-56.91; p=0.043). Additionally, Kaplan-Meier survival curves indicated that patientswith a high fold-change of down-regulated miR-193b had a significantly shorter survival time (n=19; mediansurvival=29 months) compared to patients with a low fold-change of down-regulated miR-193b (n=29; mediansurvival=54 months) (p=0.001). Overall survival time of patients with a low fold-change of up-regulated miR-196a (n=27; median survival=52 months) was significantly longer than that of patients with a high fold-changeof up-regulated miR-196a (n=21; median survival=46 months) (p=0.003). Hence, miR-193b and miR-196a maybe applied as novel and promising prognostic markers in gastric cancer.