Skip Navigation

Publication Detail

Title: AP-2alpha and AP-2gamma are transcriptional targets of p53 in human breast carcinoma cells.

Authors: Li, H; Watts, G S; Oshiro, M M; Futscher, B W; Domann, F E

Published In Oncogene, (2006 Aug 31)

Abstract: Activating enhancer-binding protein 2alpha (AP-2alpha) and activating enhancer-binding protein 2gamma (AP-2gamma) are transcription factors that bind GC-rich consensus sequences and regulate the expression of many downstream genes. AP-2alpha and AP-2gamma interact with p53 both physically and functionally. Expression microarray results in human breast carcinoma cells with forced p53 expression revealed AP-2gamma as a putative transcriptional target of p53. To confirm and extend these findings we measured the effects of forced p53 expression in human breast carcinoma cells by real-time reverse transcription-PCR, Western blotting, electrophoretic gel mobility shift assays, promoter reporter, chromatin immunoprecipitation and chromatin accessibility assays. Wild-type p53 expression rapidly induced not only AP-2gamma but also AP-2alpha mRNA. The subsequent increase in these proteins led to increased AP-2 DNA-binding and transactivating activity. Candidate p53-binding sites were identified in the AP-2alpha and AP-2gamma promoters. p53 binding to these cis-elements in vivo was also observed, together with a relaxation of chromatin structure in these regions. Finally, expression of either AP-2alpha or gamma inhibited growth of human breast carcinoma cells in vitro. Taken together, our findings indicate that these AP-2 genes are targets for transcriptional activation by p53 and suggest that AP-2 proteins may mediate some of the downstream effects of p53 expression such as inhibition of proliferation.

PubMed ID: 16636674 Exiting the NIEHS site

MeSH Terms: Adenocarcinoma; Breast Neoplasms/genetics; Cell Division; Cell Line, Tumor; DNA Primers; Female; Genes, Reporter; Genes, p53*; Humans; Oligonucleotide Array Sequence Analysis; Plasmids; Reverse Transcriptase Polymerase Chain Reaction; Transcription Factor AP-2/genetics*; Transcription Factor AP-2/metabolism; Transcription, Genetic; Transfection

Back
to Top