In vivo study of the effect of combining endostatin gene therapy with 32P-colloid on hepatocarcinoma and its functioning mechanism.

PURPOSE To investigate the therapeutic effect of combining 32P colloid radiotherapy with endostatin anti-angiogenesis therapy on hepatocellular carcinoma (HCC) cells. METHODS HCC mouse models were prepared using H22 cells and randomly divided into four groups. The mice were administered phosphate buffered saline (PBS), (32)Pcolloid, secretory endostatin encoding plasmid and combination of 32P and endostatin, respectively. Seven, 14 and 21 days after treatment the mice were sacrificed. Expression of endostatin was confirmed using western blot. Tumor growth rate, microvessel density (MVD) in the solid tumor and apoptotic index (AI) of tumor cells was analyzed using immunohistochemistry and TUNEL methods. RESULTS (1): From the western blot results, 1400 bp endostatin specific protein bands were observed in the samples from groups 3 and 4, but not in the other two groups; (2): The tumor growth rate of groups 2, 3 and 4 was significantly decreased compared to group 1 and that of group 4 was significantly lower than group 2 and 3 (3): The MVD of group 1 was greatly higher than in the other groups (4): The AI of group 4 was dramatically higher than in the other groups. CONCLUSIONS (32)Pcolloid radiotherapy or endostatin anti-angiogenesis therapy were able to inhibit the growth of HCC cells in vivo, while the combination of (32)P and endostatin showed much better therapeutic effect in HCC treatment.