p53 Responsive Gene 3 (PRG3)

Inactivation of the p53 tumor suppressor protein (TP53) has been observed in a large number of human cancers. Overexpression of p53 induces either growth arrest or apoptosis. The growth arrest function of p53 is mediated by induction of p21 (CDKN1A). To identify genes that may be involved in p53-dependent apoptosis, Horikoshi et al. (1999) used differential display analysis to compare mRNA from a human colon cancer cell line undergoing a very early stage of p53-induced apoptosis to mRNA from the same cell line before undergoing apoptosis. They identified 6 p53-responsive genes, PRG1 to PRG6. PRG3 was upregulated in the apoptotic cells. Northern blot analysis of the p53-induced colon cancer cell line detected a 4-kb PRG3 transcript.