Post-transcriptional regulation of androgen receptor mRNA by an ErbB3 binding protein 1 in prostate cancer.
Androgen receptor (AR)-mediated pathways play a critical role in the development and progression of prostate cancer. However, little is known about the regulation of AR mRNA stability and translation, two central processes that control AR expression. The ErbB3 binding protein 1 (EBP1), an AR corepressor, negatively regulates crosstalk between ErbB3 ligand heregulin (HRG)-triggered signaling and the AR axis, affecting biological properties of prostate cancer cells. EBP1 protein expression is also decreased in clinical prostate cancer. We previously demonstrated that EBP1 overexpression results in decreased AR protein levels by affecting AR promoter activity. However, EBP1 has recently been demonstrated to be an RNA binding protein. We therefore examined the ability of EBP1 to regulate AR post-transcriptionally. Here we show that EBP1 promoted AR mRNA decay through physical interaction with a conserved UC-rich motif within the 3'-UTR of AR. The ability of EBP1 to accelerate AR mRNA decay was further enhanced by HRG treatment. EBP1 also bound to a CAG-formed stem-loop in the 5' coding region of AR mRNA and was able to inhibit AR translation. Thus, decreases of EBP1 in prostate cancer could be important for the post-transcriptional up-regulation of AR contributing to aberrant AR expression and disease progression.
Greenebaum Cancer Center, Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
Hua
H
Zhou
Krystyna
K
Mazan-Mamczarz
Jennifer L
JL
Martindale
Andrew
A
Barker
Zhenqiu
Z
Liu
Myriam
M
Gorospe
Peter J
PJ
Leedman
Ronald B
RB
Gartenhaus
Anne W
AW
Hamburger
Yuexing
Y
Zhang
D020413:3' Untranslated Regions; D001483:Base Sequence; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D011132:Polyribosomes / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000378:metabolism; D020871:RNA Stability; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D011944:Receptors, Androgen / Q000235:genetics* / Q000378:metabolism
D020413:3' Untranslated Regions; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011944:Receptors, Androgen