Abstract:

Objective To study whether and how hirudin inhibits growth of the HepG2 human hepatocellular carcinoma cell line. Methods The antiproliferative effects of different hirudin concentrations on HepG2 cells were assessed using the MTT assay. The apoptosis rate was assessed by immunofluorescence， and migration and invasion ability were measured in a transwell assay. Real-time quantitative PCR was used to measure levels of VEGF mRNA，while  Western blot was used to examine levels of VEGF protein. Results The inhibition rate of HepG2 cells increased with increasing hirudin concentration and action time in a dose-dependent manner（P<0.05）. The apoptotic rate of HepG2 cells increased with increasing hirudin concentration at 48 h，the rate in each concentration group were as follows：（28.37±1.16）%，2　U/mL；（40.27±0.97）%,4　U/mL；and （76.17±1.5）%，8 U/mL（P<0.05），while hirudin decreased both the numbers of migrating cells（204±9 to 2　U/mL，163±6 to 4 U/mL，and 94±4 to 8 U/mL，P<0.05）and invasive cells （86±5 to 2　U/mL，54±7 to 4 U/mL and 20±5 to 8 U/mL，P<0.05)，and it significantly reduced levels of VEGF mRNA and protein（P<0.05）。Conclusion Hirudin inhibits proliferation， apoptosis，migration and invasion of HepG2，and it may do so by down-regulating VEGF expression.

Key words:  Liver neoplasm, Hirudin, HepG2, Proliferation, Apoptosis, Migration, Invasion, Vascular endothelial growth factor