Semiquantitative reverse transcription-polymerase chain reaction to evaluate the expression patterns of genes involved in the oestrogen pathway

The increasing number of factors to be taken into account in the oestrogen transcriptional process has created a need to develop a rapid screening met hod to evaluate their role in physiology and pathology. Molecular biology t echniques enable gene expression studies at the mRNA level with small amoun ts of tissues. We therefore developed a semi-quantitative reverse transcrip tion-polymerase chain reaction (RT-PCR) technique using fluorescent oligonu cleotides to analyse simultaneously a large panel of interrelated genes inv olved in the oestrogen transcriptional pathway using a moderately expressed housekeeping gene, the hypoxanthine phosphoribosyltransferase gene (HPRT), as the reference gene. Expression levels of oestrogen receptors (ER alpha, ER beta), cofactors AIB1, RIP140, SMRT and the Fas-associated protein-tyro sine phophatase-1 (FAP-1) genes were evaluated in breast, endometrial and o varian cancer cell lines and in three ER alpha-positive and three ER alpha- negative breast cancer tumours. This technique provides a rapid and reliabl e way to quantitate simultaneously numerous mRNAs of genes involved in the oestrogen pathway from small amounts of tissues.