Expression levels of four TFAP2A isoforms were assayed at the level of RNA and protein (via the generation of isoform-specific antibodies) in a panel of breast tumour cell lines and in tissue from normal breast and primary tumour samples.
A PBM-based study of human healthy and breast tumor tissue extracts allowed the identification of previously unknown AP2α target genes and it revealed genes whose direct or indirect interactions with AP2α are affected in the diseased tissues.
In a striking concurrence, anomalous abundance of AP-2alpha protein or its homolog AP-2gamma is also detected with HER-2/neu protein in mammary tumor-derived cell lines.
In vivo, as detected by a very sensitive nested PCR approach, methylation of the discrete AP-2alpha exon 1 region does not occur in normal breast epithelium and occurs in only 3 (16%) of 19 ductal carcinoma in situ (DCIS) lesions, but is present in 12 (75%) of 16 invasive breast tumors (P < 0.001; DCIS versus invasive cancers).
This paper describes the generation and characterization of a monoclonal antibody specific for two members of the AP-2 family of transcription factors, AP-2alpha and AP-2beta, and its subsequent application to archival primary breast tumour material.