The role of Toll-receptor 4 in tumor-associated macrophages-induced migration and invasion of Hep3B cell

Abstract

Objective The invasion and migration of Hepatocellular carcinoma (HCC) is remarkable characteristic. Tumor-associated macrophages has been found to be associated with progression and metastasis of HCC patients. Our data propose a new mechanism of tumor-associated macrophages (TAMs) promoting Hep3B invasion and migration and suggest TAMs as a new target to reverse this process. Methods (1) We successfully induced tumor-associated macrophages (TAMs) from THP-1 cells. (2) The Western blotting procedures were performed to test the Toll-receptor 4 (TLR4) protein expression of TAMs. The expression of TLR4 were down-regulated via plasmid transfection in TAMs. (3) Hep 3B was treated with TAM-conditioned medium (TAM-CM) and small hairpin RNA TLR4-conditioned medium (shRNA TLR4-CM), respectively. The wound healing assay reflected the ability of migration of Hep3B while transwell assay reflected invasion. Results Successful Induction of TAMs. Compared with control groups, Hep3B cells migrated at a much longer distance and more invasion cells in TAM-CM groups, P=0.000. After TLR4 expression of TAMs were down-regulated, the distance Hep3B migrated and the numbers Hep3B invaded were less than TAM-CM groups, P=0.001. Conclusion TAMs facilitated migration and invasion of Hep3B cell, the mechanism of which is related to the TLR4 of TAMs. Key words: Hepatocellular carcinoma; Tumor-associated macrophages; Invasion and migration; Toll-receptor 4