Effects Of Avastin On Tumor Growth Of Human Hepatocellular Carcinoma (MHCC97-H) Xenografts In Nude Mice

Objective:To explore the effects of Avastin, a monoclonal antibody developed against vascular endothelial growth factor (VEGF), on the growth of human hepatocellular carcinoma (HCC) MHCC97-H cell xenografts in nude mice.Methods:A model of human hepatocellular carcinoma was established by subcutaneous transplantation of MHCC97-H cells in nude mice. After tumor engraftment (10days),15mice were randomly divided into3groups. Treatments was designed that:the mice in control group received sterile saline1ml IP twice weekly; the mice in Avastin low dose group (BevaL group) received Avastin5mg/kg IP twice weekly; the mice in Avastin high dose group (BevaH group) received Avastin1mg IP twice weekly. Tumor diameter was measured by caliper every other day. After2weeks of treatments, all mice were killed and the tumors were obtained from xenografts. Mice and tumors were weighted; inhibition rates and tumor weight/mice weight were calculated. Vessels in tumor capsule and endothelial progenitor cells (EPC) in tumors were observed under microscope and by immunohistochemistry respectively.Results:Compared to control group, tumor volume and tumor weight/mice weight in BevaL group were decreased, and the differences were significant (P<0.05). Compared to control group, tumor volumn and tumor weight/mice weight in BevaH group were decreased, and the differences were very significant (P<0.01). Tumor growth inhibition rates of BevaL group and BevaH group are67.68%and91.80%respectively. Compared to control group, tumor weight in BevaL and BevaH groups were decreased, and the differences were significant (P<0.05). There was no significant difference of tumor volume, tumor weight/mice weight or tumor weight between BevaL and BevaH groups (P>0.05). Endothelial progenitor cells in tumors were observed in none of the3groups and tumor capsule in control group seemed to have more vessels than either BevaL group or BevaH group.Conclusions:Avastin inhibits growth of human hepatocellular carcinoma (MHCC97-H) xenografts in nude mice. For the model we establish, the anti-tumor effects of Avastin are not due to the reducing endothelial progenitor cells in tumor and subsequent inhibition of angiogenesis. Instead, Avastin inhibits tumor growth by reducing vessels in tumor capsule.