Changes of Kinesin Family Member 18 Pathway in Epithelial Mesenchymal Transformation and Effect of Butyrate on Migration and Invasion of Colon Cancer Cells

Abstract

Colon cancer is a common digestive system disease with an increasing incidence. Severe migration and invasion aggravates the deterioration of colon cancer patients. Previous studies have found that epithelial mesenchymal transition (EMT) is closely associated with early transference of colon carcinoma and abnormal changes occur in KIF18 signaling pathway. Butyrate protects colonic mucosa with a considerable effect on the colon. This study predicts that butyrate may reverse EMT process of colon cancer cells through KIF18 signaling pathway, thereby inhibiting cell migration and invasion. In this experiment, EMT model of colon cancer was used to investigate migration and invasion. Human colon cancer cell line SW1116 was cultured and assigned into control group (0 mmol/L butyrate), low concentration group (2 mmol/L), medium concentration group (4 mmol/L), and high concentration group (10 mmol/L). After 72 hours, cell migration and invasion was analyzed by Transwell assays. E-cadherin, Vimentin, and KIF18 level was detected by Western blot and quantitative real-time PCR. After treatment, cell migration and invasion was significantly inhibited compared to control dose-dependently. In addition, Vimentin and KIF18 mRNA level was significantly lower and E-cadherin mRNA was higher in treatment groups than control group in a dose-dependent manner (P < 0.05). Consistently, the profile of protein level of these molecules was similar to mRNA expression profile. Electron microscope showed that after treatment with butyrate, the surface protuberances of colon cancer cells were abnormally increased, especially the vesicular protuberances, which were the microvilli of intestinal mucosal epithelium. In conclusion, KIF18 is crucial in EMT of colon cancer cells. Butyrate may elevate E-cadherin and suppress Vimentin and KIF18 by activating KIF18 signaling, thus inhibiting invasion and migration.