Korean Red Ginseng extract reduces hypoxia-induced epithelial-mesenchymal transition by repressing NF-κB and ERK1/2 pathways in colon cancer

Background: The incidence of colorectal cancer (CRC) is increasing, with metastasis of newly diagnosed CRC reported in a large proportion of patients. However, the effect of Korean Red Ginseng extracts (KRGE) on epithelial to mesenchymal transition (EMT) in CRC is unknown. Therefore, we examined the mechanisms by which KRGE regulates EMT of CRC in hypoxic conditions. Methods: Human CRC cell lines HT29 and HCT116 were incubated under hypoxic (1% oxygen) and normoxic (21% oxygen) conditions. Western blot analysis and real-time PCR were used to evaluate the expression of EMT markers in the presence of KRGE. Furthermore, we performed scratched wound healing, transwell migration, and invasion assays to monitor whether KRGE affects migratory and invasive abilities of CRC cells under hypoxic conditions. Results: KRGE-treated HT29 and HCT116 cells displayed attenuated vascular endothelial growth factor (VEGF) mRNA levels and hypoxia-inducible factor-1α (HIF-1α) protein expression under hypoxic conditions. KRGE repressed Snail, Slug, and Twist mRNA expression and integrin αVβ6 protein levels. Furthermore, hypoxia-repressed E-cadherin was restored in KRGE-treated cells; KRGE blocked the invasion and migration of colon cancer cells by repressing NF-κB and ERK1/2 pathways in hypoxia. Conclusions: KRGE inhibits hypoxia-induced EMT by repressing NF-κB and ERK1/2 pathways in colon cancer cells. Keywords: colon cancer, epithelial-mesenchymal transition, hypoxia-inducible factors, Korean Red Ginseng extract, Panax ginseng Meyer