Downregulation of miR-193a-5p correlates with lymph node metastasis and poor prognosis in colorectal cancer

AIM:To investigate the correlation of miR-193a-5p with lymph node metastasis and postoperative survival of colorectal cancer(CRC)patients.METHODS:A total of 304 formalin-fixed,paraffinembedded specimens(69 paired cancer and normal tissues,55 primary tumors of stageⅢCRC and matched lymph nodes,and 56 primary tumors of stageⅡCRC)were included in this study.The relative expression lev-els of miR-193a-5p in the normal mucosa,primary cancer,and metastatic lymph node lesions were measured by quantitative real-time reverse transcriptase polymerase chain reaction.We evaluated the association of its expression with colorectal cancer lymph node metastasis,clinicopathological factors,and patient survival.RESULTS:The relative expression level of miR-193a-5p was significantly lower in CRC tissues than in the normal mucosa(P=0.0060).The expression levels of miR-193a-5p were lower in primary CRC tissues with lymph node metastases than in those without metastases(P=0.0006),and decreased expression of miR-193a-5p correlated with advanced lymph node metastatic stage(P=0.0007).Kaplan-Meier analysis showed that patients with low miR-193a-5p expression had decreased disease-free survival(DFS)(P=0.0026)and poor overall survival(OS)(P=0.0003).Interestingly,for the group of patients with lymph node metastases,miR-193a-5p expression was also related to survival.Patients with low miR-193a-5p expression had decreased DFS(P=0.0262)and poor OS(P=0.0230).Moreover,multivariate analysis indicated that downregulation of miR-193a-5p was an independent predictor of poor OS.CONCLUSION:Downregulation of miR-193a-5p correlates with lymph node metastasis and poor survival of CRC.miR-193a-5p may be a useful biomarker for CRC diagnosis,metastasis and prognosis prediction.