USE OF REVERSE TRANSCRIPTION-POLYMERASE CHAIN-REACTION METHODOLOGY TODETECT ESTROGEN-REGULATED GENE-EXPRESSION IN SMALL BREAST-CANCER SPECIMENS

We describe the development and use of a sensitive reverse transcripti on-PCR (RT-PCR) procedure to detect novel estrogen-regulated gene expr ession in small clinical breast cancer samples, in which such study wo uld be extremely difficult by any other molecular or immunocytochemica l means, Assay optimization for pLIV1, estrogen receptors (ERs), proge sterone receptors, and pS2 gene products was carried out on 50 primary breast cancers for which comparative Northern analysis and immunocyto chemical data were available, Using 27 amplification cycles and a 0.5 mu M primer concentration, varying expressions of the gene products we re recorded simultaneously with a constant densitometric signal for a coamplified endogenous control gene (alpha-actin). Good concordances w ere subsequently observed between pLIV1 status generated by RT-PCR and both Northern analysis (P = 0.002) and ER status by immunocytochemist ry (P = 0.0244), Agreement ras also noted between ER (P = 0.002), prog esterone receptor (P = 0.0005), and pS2 (P = 0.0023) RT-PCR and immuno cytochemical methodologies, The RT-PCR assays were then applied to 10 needle core trucut biopsies in which similar relationships were obtain ed, Our results justify the future use of this RT-PCR methodology to e xamine new estrogen-regulated genes in small breast cancer samples, an d it is envisaged that this technology will prove invaluable in many f uture breast cancer studies.