Identification and molecular cloning of novel estrogen receptor beta splice variants in human breast cancer cells

Since identification of human estrogen receptor (ER) beta gene and its first transcript, a surprisingly high number of splice variants of this mRNA have been identified. ER-beta mRNAs have previously been shown to be expressed in various human tissues, including but not limited to reproductive tissues. The so far described splice variants of ER-beta are characterized by alternative 3' exons (ER-beta 2,3,4,5) or by deletion of single or multiple exons (e.g. ER-beta delta 2). In an attempt to amplify full-length ER-beta cDNA molecules by RT-PCR from MDA-MB-231 breast cancer cells, we isolated two novel exon deleti…