MicroRNA-143 inhibits colorectal cancer cell proliferation by targeting MMP7.

Abstract

MicroRNAs (miRNAs) play critical roles in the development and progression of human malignancy. The levels of miR-143 microRNA are lower in malignant tumors - including colorectal cancer (CRC) - as it is a tumor suppressor. However, the potential mechanism of miR-143 in CRC remains largely unknown. Target prediction programs and luciferase reporter assay was used to predict the targets of miR-143. Following overexpression of miR-143 in CRC cells, target gene matrix metalloproteinase 7 (MMP7) expression was detected by quantitative real-time PCR (qRT-PCR) and western blot. In addition, the expression of MMP7 was quantified in CRC tissues and cell lines. Moreover, we determined the effect of MMP7 on CRC cell proliferation and invasion. In the present study, TargetScan predicted that miR-143 could directly bind to 3'-UTR of MMP7 mRNA, and luciferase reporter assay further supported the hypothesis that MMP7 might act as a direct target gene of miR-143. Our data showed that increased expression of miR-143 repressed MMP7 expression in CRC cells both in mRNA and protein levels. Furthermore, qRT-PCR showed that the expression of MMP7 was increased in CRC tissues and cell lines, and inversely correlated with miR-143 expression in CRC tissues. Finally, our results indicated that increased expression of MMP7 reversed the potential influence of miR-143 on CRC cell proliferation and invasion ability. Our results indicated that miR-143 might act as a tumor suppressor by targeting MMP7 during the development of CRC.