The Development of a Reverse Transcription Polymerase Chain Reaction System for Detection of Estrogen Receptor in Breast Cancer

Abstract

Estrogen receptor (ER) is widely used as an indicator of prognosis and response to endocrine treatment of primary breast cancer. ER phenotypes detected by conventional assays may not reflect their capability on binding specifically to estrogen response elements of target DNA. The reverse transcription polymerase chain reaction (RT-PCR) has been shown to offer the sensitive and specific method for measuring the ER mRNA in breast cancer. The ER-mutant gene which is positively detected in breast tumor by biochemical or immunocytochemical assays may be negatively shown by RT-PCR or vice versa. PCR technique for examining expression of ER mRNA may therefore provide a good screening method for detection of functioning ER that will affect the selection of appropriate treatment and prognosis of breast cancer patients. We have developed RT-PCR assay using b2-microglobulin as internal control for detection and relative-quantitation of ER mRNA in breast cancer tissue. Preliminary results show that the developed assay provides a sensitive and specific method for detection of ER expression in breast tumor. Also, the assay procedure is simple, rapid, non- expensive and required very small amount of breast cancer tissues.