PCR EXPRESSION ANALYSIS OF THE ESTROGEN-INDUCIBLE GENE BCEI IN GASTROINTESTINAL AND OTHER HUMAN TUMORS

A polymerase chain reaction (PCR) assay was developed to test for tumo r cell specific expression of the BCEI gene. This new marker gene, rep orted at first for human breast cancer, was found specifically active in various gastrointestinal carcinomas by previously applying immunohi stochemistry and RNA (Northern blot) analysis. Presently, by using rev erse transcription-PCR analysis, a series of primary tumor tissues and established tumor cell lines were tested for BCEI transcription. This approach was compared to immunostaining achieved by an antibody direc ted against the BCEI gene's product. The result demonstrate the superi or sensitivity of PCR by indicating the gene's expression in cases whe re immunohistochemical testing remained negative.