NF-kappaB regulates androgen receptor expression and prostate cancer growth.
Prostate cancers that progress during androgen-deprivation therapy often overexpress the androgen receptor (AR) and depend on AR signaling for growth. In most cases, increased AR expression occurs without gene amplification and may be due to altered transcriptional regulation. The transcription factor nuclear factor (NF)-kappaB, which is implicated in tumorigenesis, functions as an important downstream substrate of mitogen-activated protein kinase, phosphatidylinositol 3-kinase, AKT, and protein kinase C and plays a role in other cancer-associated signaling pathways. NF-kappaB is an important determinant of prostate cancer clinical biology, and therefore we investigated its role in the regulation of AR expression. We found that NF-kappaB expression in prostate cancer cells significantly increased AR mRNA and protein levels, AR transactivation activity, serum prostate-specific antigen levels, and cell proliferation. NF-kappaB inhibitors decrease AR expression levels, prostate-specific antigen secretion, and proliferation of prostate cancer cells in vitro. Furthermore, inhibitors of NF-kappaB demonstrated anti-tumor activity in androgen deprivation-resistant prostate cancer xenografts. In addition, levels of both NF-kappaB and AR were strongly correlated in human prostate cancer. Our data suggest that NF-kappaB can regulate AR expression in prostate cancer and that NF-kappaB inhibitors may have therapeutic potential.
Zhang
Liying
L
Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, Box 36, New York, NY 10065, USA. zhangl2@mskcc.org
Altuwaijri
Saleh
S
Deng
Fangming
F
Chen
Lishi
L
Lal
Priti
P
Bhanot
Umeshkumar K
UK
Korets
Ruslan
R
Wenske
Sven
S
Lilja
Hans G
HG
Chang
Chawnshang
C
Scher
Howard I
HI
Gerald
William L
WL
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011471:Prostatic Neoplasms / Q000235:genetics / Q000473:pathology*; D011944:Receptors, Androgen / Q000235:genetics*; D012717:Sesquiterpenes / Q000494:pharmacology; D051996:Transcription Factor RelA / Q000037:antagonists & inhibitors / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
C410798:AR protein, human; D000970:Antineoplastic Agents; D016328:NF-kappa B; D011944:Receptors, Androgen; D012717:Sesquiterpenes; D051996:Transcription Factor RelA; C002669:parthenolide