Identification and characterization of estrogen receptor variants in prostate cancer cell lines.
A sensitive semi-nested reverse transcriptase-polymerase chain reaction (RT-PCR) amplification was performed to evaluate estrogen receptor-alpha (ER-alpha) mRNA expression in prostate cancer cell lines. We demonstrated the presence of wild-type ER-alpha (wt ER-alpha) and five ER-alpha variants, designated ER-alphaA, B, C, D, and E. Unlike ER-alphaA and D, ER-alphaB, C, and E were not previously reported in normal or cancerous mammalian cells. DNA sequencing analysis of these ER-alpha variants revealed the genetic changes to be either in-frame or out-of-frame deletions. The expression of each ER-alpha variant differs significantly depending on the androgen responsiveness, tumorigenic and metastatic potentials of each prostate cancer cell line. The potential functional significance of ER-alpha variants was assessed in yeast two-hybrid and ERE promoter-reporter mammalian transcription assay systems. The results of these studies indicated that none of the ER-alpha variants can form homo- or heterodimers either with wt ER-alpha or among themselves in vivo, and that these ER-alpha variants have no demonstrable transcriptional or dominant-negative activity, as assessed in vitro.
Ye
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Molecular Urology and Therapeutics Program, Department of Urology, Box 800422, University of Virginia Health System, Charlottesville, VA 22908, USA.
Chung
L W
LW
Cinar
B
B
Li
S
S
Zhau
H E
HE
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D004252:DNA Mutational Analysis; D019281:Dimerization; D004958:Estradiol / Q000494:pharmacology; D047628:Estrogen Receptor alpha; D005091:Exons / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D017930:Genes, Reporter / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics*; D006801:Humans; D008024:Ligands; D008297:Male; D008969:Molecular Sequence Data; D011471:Prostatic Neoplasms / Q000235:genetics*; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D011960:Receptors, Estrogen / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection; D014407:Tumor Cells, Cultured; D020798:Two-Hybrid System Techniques
D047628:Estrogen Receptor alpha; D008024:Ligands; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D004958:Estradiol