Abstract: To investigate the inhibitory effect of emodin on inflammatory mediated metastasis of colon cancer cells.MTT assay was used to determine the effective concentration of emodin.The effect of emodin on migration and invasion of colon cancer cell line SW480 induced by LPS was evaluated by wound healing,Transwell,Matrigel invasion assay.The expression of inflammatory cytokines in the culture supernatants was determined by enzyme-linked immunosorbent assay after colon cancer cells were treated with LPS alone or combined with emodin.Intracellular EMT marker and inflammatory-related protein was detected by Western blot after LPS treated alone and cotreated with emodin on colon cancer cells.The lung metastasis mouse model was established to evaluate the inhibitory effect of emodin on the tumor metastasis induced by LPS.The results indicated that emodin could inhibit the proliferation,migration and invasion induced by LPS in SW480 colon cancer cells.In colon cancer cells cotreated with LPS and emodin,the level of inflammatory factors such as IL-1,TNF-α and IL-6 was reduced and western-blot analysis revealed that EMT was suppressed and expression of NF-kB and TLR4 was down-regulated when compared with treatment with LPS alone.In vivo,emodin can inhibit lung metastasis of colon cancer induced by LPS.The results suggested that emodin suppressed the EMT process of colon cancer cells by inhibiting release of inflammatory factors induced by LPS and activation of inflammatory signaling pathways,thereby inhibiting metastasis of colon cancer cells.

Key words: emodin, colon cancer, inflammatory factors, metastasis