Prognostic value of microRNA-126 and CRK expression in gastric cancer

BACKGROUND MicroRNA (miR)-126, acting as a tumor suppressor, has been reported to inhibit the invasion of gastric cancer cells in part by targeting v-crk sarcoma virus CT10 oncogene homologue (CRK). The aim of this study was to investigate the clinical significance of miR-126/CRK axis in gastric cancer. METHODS miR-126 and CRK mRNA expression levels were detected by real-time quantitative reverse transcription polymerase chain reaction in 220 self-pairs of gastric cancer and adjacent noncancerous tissues. RESULTS Expression levels of miR-126 and CRK mRNA in gastric cancer tissues were, respectively, lower and higher than those in adjacent noncancerous tissues (both P<0.001). Low miR-126 expression and high CRK expression, alone or in combination, were all significantly associated with positive lymph node and distant metastases and advanced TNM stage of human gastric cancer (all P<0.05). We also found that the overall survival rates of the patients with low miR-126 expression and high CRK expression were, respectively, shorter than those with high miR-126 expression and low CRK expression. Interestingly, miR-126-low/CRK-high expression was associated with a significantly worse overall survival of all miR-126/CRK groups (P<0.001). Moreover, multivariate analysis identified miR-126 and/or CRK expression as independent prognostic factors for patients with gastric cancer. Notably, the prognostic relevance of miR-126 and/or CRK expression was more obvious in the subgroup of patients with TNM stage IV. CONCLUSION Dysregulation of miR-126/CRK axis may promote the malignant progression of human gastric cancer. miR-126 and CRK combined expression may serve as an independent predictor of overall survival in patients with advanced gastric cancer.