miR-137 suppresses proliferation, migration and invasion of colon cancer cell lines by targeting TCF4

Colorectal cancer is cancer of the colon or rectum and is the third most prevalent form of cancer. Currently, there are several shortcomings in the prognosis and early detection of colon cancer. The present study aims to address questions pertaining to the role of microRNA (miR)-137 in colon cancer progression and the mode of regulation. The endogenous and over-expressed levels of miR-137 in three colon cancer cell lines were assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The MTT assay was used to assess cell proliferation. Cell migration and invasion assays were assessed using Transwell apparatus and Matrigel invasion chambers. The potential targets of miR-150 were predicted using TargetScan software, and one of the best scoring targets, transcription factor 4 (TCF4), was experimentally validated using western blot analysis and RT-qPCR. It was found that that miR-137 is expressed at extremely low levels in COLO205, HCT116 and SW480 cell lines. Cell proliferation, migration and invasion were inhibited subsequent to transfection of the colon cancer cell lines with miR-137. Using bioinformatics analysis, the best scoring putative targets were identified. One such target, TCF4, was experimentally validated, and it was shown that overexpression of miR-137 suppresses TCF4 in all three colon cancer cell lines. In conclusion, it was shown that miR-137 inhibits cell proliferation, migration and invasion in colon cancer cell lines by negatively regulating the expression of TCF4.