Study On Xenogeneic Placental Extracts Inducing Antitumor Immunity In A Mouse Prostatic Carcinoma Model

Objective: To explore the inhibitory effects of Xenogeneic Placental Extracts (XPE) vaccine on tumor growth in a mouse prostatic carcinoma model and to investigate the potential immunological mechanism for inhibiting tumor growth.Methods: Mouse lympholeukocyte was treated with different doses porcine placental extracts (XPE) in vitro,and Lympholeukocyte proliferation was assayed by MTT. The different doses porcine placental extracts was used before RM-1 prostatic carcinoma challenge in C57BL/6 mice and the growth of tumor was monitored; Microvessel density(MVD) was analyzed by immunohistochenistry assay; An antibody against auto-vascular endothelial growth factor (VEGF) were detected by Western blotting.Results : Compared with control groupe, lympholeukocyte proliferation was inhibited in groups treated by 2mg/ml and 4mg/ml porcine placental protein (P<0.05); Eighteen days after tumor cells inoculation,compared with normal saline group the tumors volume in XPE-immunized group with 500μg doses was significantly smaller (P<0.05);MVD owas significantly lower in 500μg XPE-immunized group than in other groups;An antibody against mouse VEGF was detectable in XPE-immunized mice serum.