TY - JOUR
T1 - Increased acid ceramidase expression depends on upregulation of androgen-dependent deubiquitinases, USP2, in a human prostate cancer cell line, LNCaP
AU - Mizutani, Naoki
AU - Inoue, Minami
AU - Omori, Yukari
AU - Ito, Hiromi
AU - Tamiya-Koizumi, Keiko
AU - Takagi, Akira
AU - Kojima, Tetsuhito
AU - Nakamura, Mitsuhiro
AU - Iwaki, Soichiro
AU - Nakatochi, Masahiro
AU - Suzuki, Motoshi
AU - Nozawa, Yoshinori
AU - Murate, Takashi
N1 - Publisher Copyright:
© 2015 The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.
PY - 2015/2/27
Y1 - 2015/2/27
N2 - Acid ceramidase (ACDase) metabolizes ceramide to sphingosine, leading to sphingosine 1-phosphate production. Reportedly, ACDase has been upregulated in prostate cancer. However, its regulatory mechanism remains unclear. LNCaP (androgen-sensitive prostate cancer cell line) but not PC3 and DU-145, (androgen-unresponsive cell lines) exhibited the highest ACDase protein. Among three cell lines, ASAH1 mRNA level was not correlated with ACDase protein expression, and the 5′-promoter activity did not show androgen dependency, suggesting the post-transcriptional regulation of ACDase in LNCaP cells. Based on these results, LNCaP was analysed further. Casodex, androgen receptor antagonist, and charcoal-stripped FCS (CS-FCS) decreased ACDase protein and activity, whereas dihydrotestosterone in CS-FCS culture increased ACDase protein and enzyme activity. MG132, a proteasome inhibitor, prevented the decrease of ACDase protein when cultured in CS-FCS, suggesting the involvement of ubiquitin/proteasome system. Reportedly, USP2, a deubiquitinase, plays an important role in LNCaP cells. USP2 siRNA decreased ACDase protein, whereas USP2 overexpression increased ACDase protein of LNCaP cells. However, SKP2, an ubiquitin E3 ligase known to be active in prostate cancer, did not affect androgen-dependent ACDase expression in LNCaP cells. Thus, ACDase regulation by androgen in androgen-sensitive LNCaP cells is mainly due to its prolonged protein half-life by androgen-stimulated USP2 expression.
AB - Acid ceramidase (ACDase) metabolizes ceramide to sphingosine, leading to sphingosine 1-phosphate production. Reportedly, ACDase has been upregulated in prostate cancer. However, its regulatory mechanism remains unclear. LNCaP (androgen-sensitive prostate cancer cell line) but not PC3 and DU-145, (androgen-unresponsive cell lines) exhibited the highest ACDase protein. Among three cell lines, ASAH1 mRNA level was not correlated with ACDase protein expression, and the 5′-promoter activity did not show androgen dependency, suggesting the post-transcriptional regulation of ACDase in LNCaP cells. Based on these results, LNCaP was analysed further. Casodex, androgen receptor antagonist, and charcoal-stripped FCS (CS-FCS) decreased ACDase protein and activity, whereas dihydrotestosterone in CS-FCS culture increased ACDase protein and enzyme activity. MG132, a proteasome inhibitor, prevented the decrease of ACDase protein when cultured in CS-FCS, suggesting the involvement of ubiquitin/proteasome system. Reportedly, USP2, a deubiquitinase, plays an important role in LNCaP cells. USP2 siRNA decreased ACDase protein, whereas USP2 overexpression increased ACDase protein of LNCaP cells. However, SKP2, an ubiquitin E3 ligase known to be active in prostate cancer, did not affect androgen-dependent ACDase expression in LNCaP cells. Thus, ACDase regulation by androgen in androgen-sensitive LNCaP cells is mainly due to its prolonged protein half-life by androgen-stimulated USP2 expression.
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U2 - 10.1093/jb/mvv039
DO - 10.1093/jb/mvv039
M3 - Article
C2 - 25888580
AN - SCOPUS:84943553052
SN - 0021-924X
VL - 158
SP - 309
EP - 319
JO - Journal of Biochemistry
JF - Journal of Biochemistry
IS - 4
ER -