TREM2 siRNA inhibits cell proliferation of human liver cancer cell lines

Liver cancer is one of the most common malignant tumors in digestive system with poor prognosis and high mortality. Recent researches suggested the important role of TREM2 in various cancers. This study aimed at investigating the effect of TREM2 siRNA on cell proliferation, apoptosis and cell circle distribution of two liver cancer cell lines, 97H and HepG2 cells with significant expression level of TREM2. 25 liver cancer samples containing tumor tissues and normal tissues were detected for the TREM2 expression level using real-time PCR. 97H and HepG2 cells were taken out for the following study. CCK8 assay was preformed to evaluate the cell proliferation. Cell apoptosis and cell cycle of 97H and HepG2 cells were identified using flow cytometry. In addition, apoptosis and cell cycle related proteins caspase3, Bax, Bcl2, PCNA, CDK1 and CDC25C were measured for the expression level by using Western blot. Furthermore, in vivo study using nude mice was evaluated for the inhibition ability of TREM2 siRNA on tumor formation of 97H cells. As a result, expression of TREM2 exhibited a higher level in tumor tissues than that in normal tissues. The cell proliferation of 97H and HepG2 cells was inhibited by TREM2 siRNA time-dependently. Besides, TREM2 siRNA induced cell apoptosis and arrested cell cycle at S phase effectively. The regulation of TREM2 siRNA on the proteins revealed the possible mechanism involved in the cell apoptosis and cell cycle. The tumor size obtained from in vivo study indicated the inhibition capability of TREM2 siRNA on the formation of tumor. In conclusion, TREM2 siRNA inhibited cell proliferation of human liver cancer cells 97H and HepG2 by targeting caspase/Bcl and CDK1 signaling pathway, suggesting the potential therapy using TREM2 siRNA for liver cancer treatment.