Anti-tumor activity of a recombinant endoglin-MIP3α Fc-fusion protein in mice with hepatocellular carcinoma

ABSTRACT

Objective: To investigate the effects of a recombinant endoglin-macrophage inflammatory protein 3α Fc-fusion protein (EM) vaccine on tumor angiogenesis and growth in mice with H22 hepatocellular carcinoma. Methods: An in vivo hepatoma mouse model was established. Seven days after subcutaneous inoculation of H22 tumor cells, mice were randomly divided into four groups: EM, endoglin Fc-fusion protein, macrophage inflammatory protein 3α Fc-fusion protein, and normal saline groups. Tumor volume and survival rate of mice were studied at 3-day intervals. Microvessel density of the tumors and tumor cell proliferation were detected by immunohistochemistry, and tumor cell apoptosis was detected by TdT-mediated biotinylated-dUTP nick-end label staining. The number of CD11c and CD86 positive dendritic cells were detected by flow cytometry. Results: Compared with the other groups, the tumor volume became smaller, and the survival time was longer in the EM-treated group. Besides, microvessel density and cell proliferation index were significantly lower, while the tumor cell apoptosis index was significantly higher in the EM-treated group. Besides the number of CD11c and CD86 positive dendritic cells in EM-treated mice was larger than that in other groups. Conclusions: EM Fc-fusion protein could effectively inhibit tumor growth through inhibiting endoglin-related tumor angiogenesis and cell proliferation, promoting tumor cell apoptosis, and could induce a certain degree of antitumor immune responses.