Androgen receptor and prostate apoptosis response factor-4 target the c-FLIP gene to determine survival and apoptosis in the prostate gland.
Androgen receptor (AR) is a ligand-activated transcription factor that mediates the action of androgens and is essential for the growth, function, and cell differentiation of the prostate gland. Here, we demonstrated that the prostate apoptosis response factor-4 (par-4) functions as a novel AR coactivator. Par-4 physically interacted with the DNA-binding domain of AR, enhanced AR interaction with DNA, and increased AR-dependent transcription. Par-4 enhanced the c-FLIP promoter activity and was recruited on to the c-FLIP gene in the presence of androgens, and the dominant-negative par-4 decreased c-FLIP expression. These results suggest that, in addition to its proapoptotic function, par-4 acts as a novel transcription cofactor for AR to target c-FLIP gene expression. In addition, we demonstrated that loss of c-FLIP expression was essential for castration-induced apoptosis in the prostate gland and that enhanced c-FLIP expression was associated with prostate cancer progression to the androgen-resistant stage. Our data shed light on a transcription-mediated mechanism for the effects of the AR pathway on cell survival and apoptosis.
Gao
Shen
S
Department of Cancer Biology, The University of Texas M D Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030, USA.
Wang
Hua
H
Lee
Peng
P
Melamed
Jonathan
J
Li
Caihong X
CX
Zhang
Fahao
F
Wu
Hong
H
Zhou
Liran
L
Wang
Zhengxin
Z
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein / Q000235:genetics / Q000378:metabolism*; D002369:Castration; D002460:Cell Line; D002470:Cell Survival / Q000502:physiology*; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D011467:Prostate / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D020836:Protein Structure, Quaternary; D011944:Receptors, Androgen / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D050436:Regulatory Elements, Transcriptional; D014158:Transcription, Genetic
D051017:Apoptosis Regulatory Proteins; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; C506386:CFLAR protein, human; D010455:Peptides; D011944:Receptors, Androgen; D011993:Recombinant Fusion Proteins; C101296:prostate apoptosis response-4 protein