AB112. Expression of brain-specific angiogenesis inhibitor 1 and association with p53, microvessel density and vascular endothelial growth factor in the tissue of human bladder transitional cell carcinoma

Objective: Brain-specific angiogenesis inhibitor 1 (BAI1) was initially described in 1997, and there have since been a number of studies on its expression in different types of cancer. The aim of the present study was to investigate the expression levels of BAI1 in bladder transitional cell carcinoma (BTCC) at different stages and the mechanism by which it inhibits tumor endothelial cell proliferation.

Methods: Normal bladder mucosa biopsy specimens were obtained as the control group, and human BTCC biopsy specimens were used as the study group. Immunohistochemical assays were used to detect the expression levels of BAI1, vascular endothelial growth factor (VEGF) and mutant p53, in addition to microvessel density (MVD) in the tissues. Western blotting was used to analyze the differential expression of BAI1 in the two samples.

Results: Statistical analysis was performed, which indicated that BAI1 expression levels in the normal bladder mucosa group were significantly higher than those in the BTCC group and were associated with clinical staging. BAI1 levels in the T1 stage BTCC tissues were higher than those in the T2–4 stage BTCC tissues (P<0.05). BAI1 expression levels were negatively correlated with those of VEGF (r=−0.661, P<0.001), mutant p53 (r=−0.406, P=0.002) and with the MVD (r=−0.675, P<0.001).

Conclusions: BAI1 may be involved in the negative regulation of BTCC microvascular proliferation, and its expression may be associated with a reduction in p53 mutations.

Keywords: Brain-specific angiogenesis inhibitor 1 (BAI1); bladder urothelial carcinoma; bladder epithelial cells; vascular endothelium