RELEASE OF AN INHIBITOR OF ANGIOGENESIS UPON INDUCTION OF WILD-TYPE P53 EXPRESSION IN GLIOBLASTOMA CELLS

The earliest genetic alteration in human astrocytoma progression is mu tation of the p53 tumour suppressor gene, while one of the earliest ph enotypic changes is the stimulation of neovascularization. Here, we te sted the role of p53 in the angiogenic process by introducing a tetrac ycline-regulated wild type p53 gene into null glioblastoma cells. The parental cells expressed strong angiogenic activity while upon inducti on of wild type, but not mutant, p53 expression, the cells secreted a factor able to neutralize the angiogenicity of the factors produced by the parental cells as well as of basic fibroblast growth factor.