Aberrant expression of miR-199a-3p and its clinical significance in colorectal cancers

Aberrant miR-199a-3p expression has been reported in several cancers. However, the clinical significance of miR-199a-3p in human colorectal cancer has not been addressed. In this study, we detected miR-199a-3p expression in 92 colorectal cancer cases to evaluate its clinicopathologic characteristics in colorectal cancer. We showed that miR-199a-3p expression was significantly upregulated in cancer tissues than NATs. Clinicopathologic analysis revealed that high miR-199a-3p expression contributed to more advanced lymphatic invasion, lymph node metastasis, liver metastases and late TNM stage in colorectal cancer. Kaplan-Meier analysis showed that high expression of miR-199a-3p could lead to a significantly shorter overall survival rate. Cox's proportional hazards model also indicated that the high expression of miR-199a-3p could serve as an independent and significant prognostic factor for survival. We transfected miR-199a-3p inhibitor into SW480 cells and observed that miR-199a-3p inhibitor could markedly inhibit the cell proliferation. Flow cytometry analysis also found that miR-199a-3p inhibitor could cause G0/G1 arrest, decreased percentage of S and G2/M phase and induce more cell apoptosis in SW480 cells. These results suggested that miR-199a-3p may serve as an efficient biomarker for diagnosis and novel prognostic indicator in colorectal cancer.