HUMAN GLIOMAS WITH WILD-TYPE P53 EXPRESS BCL-2

Human astrocytomas frequently overexpress wild-type p53, which suggest s that gliomas have evolved a mechanism to subvert p53-mediated apopto sis, bcl-2 inhibits apoptosis mediated by p53, and it is expressed in several human cancers, We therefore examined a series of human gliomas to determine whether bcl-2 is expressed and whether this expression i s associated with tumors which have wild-type p53, Twenty-eight paraff in-embedded gliomas (3 WHO grade II, 13 grade III, 12 grade IV) were i mmunohistochemically stained for bcl-2 and p53, p53 mutations were ide ntified with single strand conformation polymorphism and DNA sequencin g, Sixteen of 28 (57%) tumors expressed bcl-2, and bcl-2 expression wa s associated with mild-type p53 (P < 0.01), Among gliomas which overex pressed p53, bcl-2 was positive in 7 of 7 tumors with wild-type p53 bu t in only 1 of 7 with mutant p53 (P < 0.01), We conclude that bcl-2 is frequently expressed in human gliomas and that expression is more com mon in tumors with wild-type p53.