ABSTRACT
Objective To investigate the expression of semaphorin 3A (Sema3A) and its receptor neuropilin-1 (NRP-1) in gastric cancer and its correlation with microvessel density (MVD), and then to explore the effect of recombinant human Sema3A on angiogenesis of gastric cancer and the associated mechanisms. Methods Forty cases of gastric cancer tissues and its corresponding adjacent normal tissues were used to detecte the expression of Sema3A, NRP-1 and MVD in tissues by immunohistochemistry method . The expression level of Sema3A in serum of gastric cancer patient group and normal control group were measured by Enzyme-linked immuno-sorbent assay (ELISA). Western blotting was used to detect the expression of Sema3A and NRP-1 in five gastric cancer cell lines (MGC-803,HGC-27,MKN-28,SGC-7901,MKN-45) and human gastric mucosal epithelial cell (GES-1). Transwell chamber was used to construct non-contact in vitro co-culture system, in which the effects of different concentrations of recombinant human Sema3A on angiogenesis in gastric cancer were analyzed by tube formation assay preliminarily. The expression levels of vascular endothelial growth factor receptor 2 (VEGFR2) and NRP-1 in co-culture system were detected by Western blotting. Results The expression levels of Sema3A in gastric cancer tissues, cell lines and patient serum were significantly lower than that in the control group(P<0. 05), while the expression of NRP-1 in gastric cancer tissues and MKN-28 cells was significantly increased, and both of them were associated with TNM staging of gastric cancer (P < 0. 05) . In vitro co-culture system, The tube forming abilities of human umbilical vein endothelial cell (HUVEC) were decreased in recombinant human Sema3A treated group, and this phenomenon was concentration dependent. The expression of VEGFR2 protein was down-regulated by recombinant human Sema3A. Conclusion The expression of Sema3A was decreased in gastric cancer tissues, cell lines and patient serum, and negatively correlated with microvessel density. The recombinant human Sema3A could inhibit the angiogenesis of gastric cancer in vitro, which may be related to down-regulation of VEGFR2 protein expression.
ABSTRACT
Objective Establishment of orthotopic transplantation tumor model of human choriocarcinoma in nude mice. Methods Human choriocarcinoma cell line JAR was cultured and the single cell suspension was subcutaneously injected into five 8-week-old BALB / c nude mice to establish subcutaneous xenograft model. After subcutaneous tumor was formed in nude mice, the tumor tissue was taken under aseptic conditions and cut into 1 mm