MicroRNA‐4429 restrains colorectal cancer cell invasion and migration via regulating SMAD3‐induced epithelial–mesenchymal transition

Abstract

Colorectal cancer (CRC) is one of the commonest human cancers and the fourth primary cause of cancer‐related death. Previous studies have reported that miR‐4429 develops anticancer function in follicular thyroid carcinoma and non‐small cell lung cancer. However, whether miR‐4429 is implicated in the CRC progression remains to be clarified. The aim of our current study was to explore the potential role of miR‐4429 in CRC. According to the result of quantitative real‐time polymerase chain reaction analysis, miR‐4429 was expressed at a low level in CRC cells. Gain‐of‐function assays showed that the upregulation of miR‐4429 inhibited cell proliferation, migration, invasion, and epithelial–mesenchymal transition (EMT) process in CRC, whereas miR‐4429 inhibition led to the opposite results. It was uncovered from mechanism experiments that miR‐4429 targeted forkhead box M1 (FOXM1) and therefore regulating SMAD family member 3 (SMAD3) expression. Rescue experiments elucidated that miR‐4429 influenced cell proliferation, migration, invasion, and EMT process in CRC by targeting FOXM1 to inactivate SMAD3. In conclusion, our study revealed that miR‐4429 targeted FOXM1 to decrease SMAD3 expression and thus impeding cell proliferation, migration, invasion, and EMT process of CRC cells.