Isolation of differentially expressed cDNAs from p53-dependent apoptotic cells: Activation of the human homologue of the Drosophila peroxidasin gene

Inactivation of the p53 tumor suppressor protein has been observed in a lar ge number of human cancers. Overexpression of p53 induces either growth arr est or programmed cell death (apoptosis). The growth arrest function of p53 is mediated by induction of p21 (WAF1/CIP1), but the mechanisms underlying p53-dependent apoptosis are still largely unknown. To investigate these me chanisms, we have identified six differentially expressed transcripts in a human colon cancer cell line undergoing p53-dependent apoptosis. One of the p53-responsive genes showed significant homology to Drosophila peroxidasin , an extracellular matrix-associated peroxidase, and is likely to be its hu man homologue. Our results suggest a possible connection between p53-depend ent apoptosis and the production of reactive oxygen species, (C) 1999 Acade mic Press.