The Effect Of HMGB1on Invasive And Migration Ability To Hepatoma Cell And The Preliminary Study On Its Mechanism

Objectives: Primary hepatic carcinoma is one of the most commonly seenmalignant tumors in clinical practice. According to the latest statistics, thenumber of new cases of liver cancer is almost600thousand throughout the worldevery year, which ranks fifth in cases of malignant tumors. The research on therelationship between HMGB1and hepatocellular carcinoma has already beenlaunched. Recent research result suggests that the content of HMGB1detectedin cases of gastric cancer, esophageal cancer, pancreatic cancer and coloncancer is increasing, but its specific mechanism of action is not clear yet.In our research, by detecting contents of HMGB1in liver cancer, para-carcinomatissue and normal liver tissue, combined with the synthetic of the usage of RNAinterference technology and siRNA targeting on HMGB1, we observe HMGB1’sinfluence on the ability of Invasion and metastasis of human hepatocellularcarcinoma cell line HepG2and conduct discussion and analysis of its meaningand mechanism.Methods:(1)collect and extract10samples of hepatocellular carcinoma tissue which is proved by pathological examination, and10samples of normalliver tissue adjacent to hepatocellular carcinoma, then make comparison between the two groups. Use RT-PCR and Western blot to detect the differenceof contents of HMGB1detected in cases of hepatoma tissue than in adjacenttissues, human hepatocellular carcinoma cell line HepG2and normal hepatic cell line HepG2.(2)Use RNA interference technology to synthesize3pairs ofHMGB1-siRNA specific to HMGB1and then let them infect HepG2. Set up blankgroups and comparison groups and use Western blot technology to test genetic silent effect.(3)Choose the HMGB1-siRNA group with the best genetic silent effect and apply it into transmembrane and plane migration assays. Thendetect the change of invasion and migration ability of cell.(4)Separately test the further expression level of MMP2, MMP9, ICAM1and TIMP2’s mRNA andprotein of HMGB1-siRNA after its infection and entrance into HepG2by usingRT-PCR and Western blot.Results: The Experimental result shows that the expression level of HMGB1in liver cancer tissue has increased significantly compared with that inpara-carcinoma tissue, and the expression level of HMGB1in hepatocellularcarcinoma cell line HepG2has also increased significantly compared with that in normal liver cell line(both P<0.05);the expression level of HMGB1inHepG2can be significantly decreased after the HMGB1-siRNA infection, especially the HMGB1-siRNA-1has the highest genetic silent efficiency (P<0.05),andthe suppression efficiency of40nM HMGB1-siRNA-1towards HMGB1is as high as80%and above after24hours,48hours and72hours, then decreases significantly after96hours(both P<0.05); when use40nM HMGB1-siRNA-1to infect HepG2, the invasion and migration ability of HepG2cell decreases significantly after24hours(both P<0.05). After the infection, the expression level of mRNA of MMP2, MMP9, ICAM1decreases significantly, while the expression level of mRNA of TIMP2increases significantly(both P<0.05).Conclusions: The high expression level of HMGB1in liver cancer can promotethe invasion and migration of hepatoma carcinoma cell. By using HMGB1-siRNA to suppression the expression level of HMGB1in hepatoma carcinoma cell cansignificantly weaken the invasion and migration ability of tumor cells. Afterthe suppression of HMGN1, the expression level of MMP2, MMP9and ICAM1decreasessignificantly, while the expression level of TIMP2increases significantly,which means the he invasion and migration ability of HMGB1towards hepatomacarcinoma cell is relative to the expression level of MMP2, MMP9, ICAM1and TIMP2.This may be the potential target gene in the treatment of liver cancer.