Inhibition of autophagy by 3-methyladenine promotes migration and invasion of colon cancer cells through epithelial mesenchymal transformation

BACKGROUND: Colon cancer is the third leading cause of tumor-related deaths in the world. Inhibition of autophagy in the treatment of malignant tumors has attracted extensive attention. However, the association between inhibition of autophagy by 3-methyladenine (3-MA) and epithelial mesenchymal transformation (EMT) in colon cancer cells has not yet been fully elucidated. METHODS: In this study, colon cancer cell lines (LOVO and SW620) were treated with 3-MA. Wound healing assays and transwell assays were used to detect the effect of inhibition of autophagy on the migration and invasion of colon cancer cells. The expression of EMT-associated markers, Twist1, E-cadherin, and vimentin, in colon cancer cells with and without 3-MA treatment was detected by Western blotting, immunohistochemistry, immunofluorescence staining, and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). RESULTS: Our data showed that inhibition of autophagy by 3-MA significantly enhanced the migration and invasion of colon cancer cells. At the molecular level, inhibition of autophagy upregulated the expression of Twist1 and vimentin, downregulated the expression of E-cadherin, and induced the EMT of colon cancer cells. CONCLUSIONS: Inhibition of autophagy by 3-MA upregulated the expression of Twist1 in colon cancer cells and promoted cancer cell migration and invasion through EMT. Inhibition of autophagy may have adverse effects on colon cancer.