EXPRESSION OF BAX, BCL-2, WAF-1, AND PCNA GENE-PRODUCTS IN AN IMMORTALIZED HUMAN ENDOTHELIAL-CELL LINE UNDERGOING P53-MEDIATED APOPTOSIS

Transfection of the wild-type p53 gene into an immortalized human endo thelial cell line (ECV-304) by recombinant adenoviral delivery resulte d in high level expression of the wild-type p53 protein and induction of apoptosis. Increases in the number of apoptotic cells were observed within 12 h after infection of ECV-304 cells with recombinant p53 ade novirus, as determined by the appearance of internucleosomal DNA fragm entation ladders and by TUNEL and electron microscopic analyses, Contr ol cells infected with a beta-galactosidase recombinant adenovirus exh ibited little or no increase in apoptosis over uninfected cells, The e xpression of Waf-1 and Bar gene products were increased substantially in apoptotic ECV-304 cells as determined by Northern blot, reverse tra nscription-PCR and immunoblotting analyses. Lesser increases in the ex pression of the PCNA gene were detected in ECV-304 cells undergoing ap optosis. Both control and apoptotic ECV-304 cells did not express dete ctable levels of Bcl-2 mRNA or protein in Northern blotting and immuno blotting analyses, respectively, The data suggest a role for the Bar g ene product in p53-mediated apoptosis of endothelial cells.