[Detection of estrogen receptor (ER) mRNA by use of reverse transcriptase-polymerase chain reaction (RT-PCR) assay; comparison with dextran coated charcoal (DCC) assay and immunocytochemical assay].

A new method for estrogen receptor (ER) mRNA was performed on 33 human breast tumors, using a reverse transcriptase-polymerase chain reaction (RT-PCR) assay by the method of Fuqua et al. In a preliminary experiment using the MCF-7 breast tumor cell line, ER/beta-actin ratio was almost same. ER protein was estimated by a dextran coated charcoal (DCC) assay and by an ER-immunocytochemical (ER-ICA) assay using a specific monoclonal antibody. We found RT-PCR assay correlates with ER-ICA assay (r = 0.664, p less than 0.01), whereas no significant correlation was seen between RT-PCR assay and DCC assay. These results suggests that RT-PCR assay is suitable for detection of ER from small amounts of tissue.