title: Differences in estrogen receptor alpha variant messenger RNAs between normal human breast tissue and primary breast carcinomas.
abstract: We evaluated the differences in prevalence and functional activity of human estrogen receptor alpha (hER) variant mRNA between 21 normal breast tissues and 41 primary breast carcinomas using a functional assay in yeast for the hER First, we found that the presence of wild-type hER, relative to the total amount of hER, differs markedly (P < 0.0001) between normal breast tissue (median, 85% wild-type hER) and breast tumors (median, 74% wild-type hER). Second, the hER variants with altered function that are present in normal breast tissue are mainly one-exon deleted splicing variants (median, 100%), whereas in breast tumors only half of all variants lack just one single exon (median, 50%; P < 0.0001). Our results suggest that hER-dependent estrogen responsiveness of breast tissue may change during tumor outgrowth, indicating that specific hER variants may play a role in breast cancer development or progression.
authors.affiliation: Division of Experimental Therapy, The Netherlands Cancer Institute, Amsterdam.
authors.forename: M A
authors.initials: MA
authors.lastname: van Dijk
authors.forename: A A
authors.initials: AA
authors.lastname: Hart
authors.forename: L J
authors.initials: LJ
authors.lastname: van 't Veer
mesh_terms: D000328:Adult; D000368:Aged; D001940:Breast / Q000737:chemistry*; D001943:Breast Neoplasms / Q000737:chemistry*; D047628:Estrogen Receptor alpha; D005260:Female; D006801:Humans; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis*; D011960:Receptors, Estrogen / Q000235:genetics*
chemical_list: D047628:Estrogen Receptor alpha; D012333:RNA, Messenger; D011960:Receptors, Estrogen