title: Quantitative analysis of estrogen receptor-beta mRNA and its variants in human breast cancers.
abstract: We have carried out a quantitative analysis of ER-alpha and ER-beta mRNA expression in normal (n = 11) and breast cancer (n = 112) tissues using a real-time (Taq-Man) PCR assay. Expression of ER-beta mRNA variants has also been studied by triple-primer PCR assay. ER-alpha mRNA levels in normal breast tissues were significantly (p < 0.01) lower than those in ER-positive breast cancers but not significantly different from those in ER-negative breast cancers. However, ER-beta mRNA levels in normal breast tissues were significantly (p < 0.01) higher than those in ER-positive and ER-negative breast cancers. Proportions of ER-beta1 and ER-beta2 mRNA expression among total ER-beta mRNA expression were significantly higher and those of ER-beta5 and ER-beta5; mRNA were significantly lower in normal breast tissues than in ER-positive and ER-negative breast cancers. ER-beta mRNA levels and proportions of ER-beta mRNA variants did not show any significant correlation with age, tumor size, lymph node status and histological grade. Our results demonstrate that ER-alpha mRNA is up-regulated and ER-beta mRNA is down-regulated during carcinogenesis of breast cancers. Changes in proportions of ER-beta mRNA variants are also implicated in this process.
authors.affiliation: Department of Surgical Oncology, Osaka University Medical School, Osaka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Iwao
authors.forename: Y
authors.initials: Y
authors.lastname: Miyoshi
authors.forename: C
authors.initials: C
authors.lastname: Egawa
authors.forename: N
authors.initials: N
authors.lastname: Ikeda
authors.forename: S
authors.initials: S
authors.lastname: Noguchi
mesh_terms: D000328:Adult; D000368:Aged; D017398:Alternative Splicing; D001943:Breast Neoplasms / Q000175:diagnosis / Q000235:genetics*; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005260:Female; D005819:Genetic Markers; D014644:Genetic Variation; D006801:Humans; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011379:Prognosis; D012333:RNA, Messenger / Q000032:analysis; D011960:Receptors, Estrogen / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005819:Genetic Markers; D012333:RNA, Messenger; D011960:Receptors, Estrogen