Estrogen Receptor Mutants/Variants in Human Breast Cancer

摘要

Our results suggest that estrogen receptor mediated signal transduction is complex and multifaceted in human breast cancer. We have identified the frequent expression of several alternatively spliced variants of the classical ER-alpha as well as the expression of a second novel ER gene (ER- Beta) and several (ER-Beta) variants, at least, at the mRNA level, in both normal and neoplastic human breast tissues. Further we have both published and preliminary data showing alterations in the relative expression of several of these ER-like molecules during human breast tumorigenesis and breast cancer progression. In particular marked alterations of the relative expression of several ER-alpha variant mRNAs and the relative expression of ER-alpha and (ER- Beta) mRNA occurs between normal breast tissue and primary breast tumors. Our data suggest that marked alterations of several players involved in estrogen signal transduction occur during breast tumorigenesis in particular, and these changes may contribute to the altered estrogen sensitivity that appears to occur during breast tumorigenesis.