title: Estrogen receptor alpha-negative breast cancer tissues express significant levels of estrogen-independent transcription factors, ERbeta1 and ERbeta5: potential molecular targets for chemoprevention.
abstract: We have investigated the expression of two estrogen receptor beta (ERbeta) isoforms, ERbeta1 and ERbeta5, which activate gene transcription independent of estrogen or growth factors, in ERalpha-negative breast cancer tissues. We report here, for the first time, that ERalpha-negative tissues express significant levels of ERbeta1 and ERbeta5, and their expression levels are not different from levels in ERalpha positive tumors. However, significant differences exist between the two racial groups, African American and Caucasian, in that the patients from the former group express higher levels of ERbeta1 and ERbeta5 but not ERalpha. These two transcription factors could be potential molecular targets for designing chemopreventive drugs to treat ERalpha-negative breast cancers.
authors.affiliation: Department of Biochemistry and Molecular Biology, Howard University College of Medicine, Washington, District of Columbia 20059, USA. ipoola@howard.edu
authors.forename: Indira
authors.initials: I
authors.lastname: Poola
authors.forename: Suzanne A W
authors.initials: SA
authors.lastname: Fuqua
authors.forename: Robert L
authors.initials: RL
authors.lastname: De Witty
authors.forename: Jessy
authors.initials: J
authors.lastname: Abraham
authors.forename: Josephine J
authors.initials: JJ
authors.lastname: Marshallack
authors.forename: Aiyi
authors.initials: A
authors.lastname: Liu
mesh_terms: D001741:Black or African American / Q000235:genetics; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy / Q000208:ethnology / Q000235:genetics*; D047628:Estrogen Receptor alpha / Q000235:genetics* / Q000378:metabolism; D047629:Estrogen Receptor beta / Q000235:genetics / Q000378:metabolism; D004967:Estrogens / Q000502:physiology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D044465:White People / Q000235:genetics
chemical_list: D000970:Antineoplastic Agents; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens; D020033:Protein Isoforms; D012333:RNA, Messenger; D014157:Transcription Factors