Cloning and characterization of BAI2 and BAI3, novel genes homologous to brain-specific angiogenesis inhibitor 1 (BAI1).

We have identified two novel human genes homologous to BAI1 (brain-specific angiogenesis inhibitor 1), an angiogenesis inhibitor that is a candidate for involvement in development of glioblastoma. Like BAI1, these two genes, designated BAI2 and BAI3, were specifically expressed in brain, and are likely to be expressed in the same type of cells. However, in spite of similar tissue specificity among the three BAI genes, only BAI1 is transcriptionally regulated by p53. BAI3 expression was absent in two of nine glioblastoma cell lines examined and was significantly reduced in three of the remaining seven. These data suggest that members of this novel gene family may play important roles in suppression of glioblastoma. BAI1, BAI2 and BAI3 were mapped to 8q24, 1p35 and 6q12, respectively.