title: Expression of estrogen receptor (ER-alpha and ER-beta) mRNA in human prostate cancer.
abstract: OBJECTIVE
  The distribution of the two estrogen receptors (ER-alpha, ER-beta) in human prostate tissue have not been fully clarified, so the present study investigated the mRNA expression of the receptors to explain the broad spectrum of estrogen activity in prostate cancer.
  
  
  METHODS
  Four human prostate cancer cell lines (LNCap, JCA-1, DU-145 and PC-3) and 24 pairs of untreated prostate cancer tissue and noncancerous tissue from resected prostate glands were subjected to RT-PCR testing.
  
  
  RESULTS
  Both LNCap and JCA-1 expressed the mRNA of both receptors, but DU-145 and PC-3 only expressed ER-beta mRNA. In the human prostate tissue samples, 20 of the 24 prostate cancer tissues expressed ER-alpha, and 23 of the 24 expressed ER-beta. Of the 24 noncancer tissues, 14 expressed ER-alpha mRNA and 17 expressed ER-beta mRNA. The incidence of ER-beta mRNA expression between the paired cancer and noncancer tissues was statistically significantly different (p<0.05).
  
  
  CONCLUSIONS
  A higher incidence of ER-beta mRNA expression in untreated prostate cancer tissues was observed. Furthermore, the absence of ER-alpha mRNA and the presence of ER-beta mRNA expression in hormone-independent and/or untreated prostate cancer cells leads to a tentative speculation of the mechanism of the hormone refractory feature of prostate cancer.
authors.affiliation: Department of Urology, Tokyo Medical University, Tokyo, Japan. takaaki@tokyo-med.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Ito
authors.forename: M
authors.initials: M
authors.lastname: Tachibana
authors.forename: S
authors.initials: S
authors.lastname: Yamamoto
authors.forename: J
authors.initials: J
authors.lastname: Nakashima
authors.forename: M
authors.initials: M
authors.lastname: Murai
mesh_terms: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens / Q000096:biosynthesis* / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011960:Receptors, Estrogen / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens; D012333:RNA, Messenger; D011960:Receptors, Estrogen