Preparation and identification of monoclonal antibody against human hepatocellular carcinoma with a novel immunization

Inhibitory effects of a chimeric anti-VEGFR-2 Fab antibody on tumor growth and angiogenesis in an orthotopic xenograft mouse model of hepatocellular carcinoma

AIM: To investigate the inhibitory effects of a mouse chimeric anti-VEGFR-2 Fab antibody on tumor growth and angiogenesis in an orthotopic xenograft mouse model of hepatocellular carcinoma.

METHODS: The antigen-binding activity of cFab antibody was assessed by ELISA. An orthotopic xenograft mouse model of hepatocellular carcinoma was created by direct injection of H22 cells into the liver parenchyma of ICR mice. Twenty-four ICR mice bearing orthotopic HCC were divided into two groups: control group (treated with normal saline) and cFab group (treated with cFab antibody). After the treatment, tumor weight and mouse survival time were compared between the two groups. Histological changes and microvessel density (MVD) in tumors were also evaluated.

RESULTS: The chimeric anti-VEGFR-2 Fab antibody exhibited a strong binding activity to VEGFR-2. Tumor size in the cFab group was significantly decreased compared with the control group (313.9 mm³ ± 41.9 mm³vs 635.4 mm³ ± 70.1 mm³, P < 0.05); and the mice of the cFab group had a significantly longer survival time (20.0 d vs 13.0 d, Long-rank test χ² = 4.611, P = 0.032). The MVD in the cFab group was also significantly lower than that in the control group (34.48 ± 1.39 vs 9.56 ± 1.26,P < 0.05).

CONCLUSION: The chimeric anti-VEGFR-2 Fab antibody can inhibit tumor growth in an orthotopic xenograft mouse model of hepatocellular carcinoma possibly by inhibiting tumor angiogenesis.