TY - JOUR
T1 - Transcriptional regulation of neutral sphingomyelinase 2 in all-trans retinoic acid-treated human breast cancer cell line, MCF-7
AU - Ito, Hiromi
AU - Tanaka, Kouji
AU - Hagiwara, Kazumi
AU - Kobayashi, Misa
AU - Hoshikawa, Asuka
AU - Mizutani, Naoki
AU - Takagi, Akira
AU - Kojima, Tetsuhito
AU - Sobue, Sayaka
AU - Ichihara, Masatoshi
AU - Suzuki, Motoshi
AU - Tamiya-Koizumi, Keiko
AU - Nakamura, Mitsuhiro
AU - Banno, Yoshiko
AU - Nozawa, Yoshinori
AU - Murate, Takashi
N1 - Funding Information:
Basic Research C from Ministry of Education, Culture, Sports, Science and Technology, Grant No. 23590667.
PY - 2012/6
Y1 - 2012/6
N2 - Effects of all-trans retinoic acid (ATRA) on sphingomyelinase expression were examined using MCF-7 (ATRA-sensitive) and MDA-MB-231 (ATRA-resistant) breast cancer cells. Increased NSMase activity, NSMase2 mRNA and protein were observed in ATRA-treated MCF-7 but not in ATRA-treated MDA-MB-231. Increased NSMase2 mRNA of ATRA-treated MCF-7 was mostly due to enhanced transcription. Promoter analysis revealed the important 5′-promoter region of NSMase2 between -148 and -42 bp containing three Sp1 sites but no retinoic acid responsive elements. Experiments using mutated Sp1 sites of the NSMase2 promoter, Mithramycin A (a Sp inhibitor) and Sp family over-expression demonstrated the importance of Sp family protein and the three Sp1 sites for ATRA-induced NSMase2 transcription of MCF-7 cells. Although no quantitative change of bound Sp1 on NSMase2 promoter region after ATRA treatment was detected, Sp1 phosphorylation (activation) by ATRA was observed. Interestingly, PKCδ was involved in ATRA-induced increased NSMase2 transcription. ATRA-induced PKCδ phosphorylation and then activated PKCδ phosphorylated Sp1. Chromatin immunoprecipitation (ChIP) assay showed Sp1, RARα and RXRα complex formation in MCF-7 cells regardless of ATRA treatment and ATRA-induced acetylated histone H3 of the 5′-promoter. Thus, NSMase2 mRNA expression enhanced by ATRA was due to increased transcription via phosphorylated Sp1 caused by PKCδ activation, followed by chromatin remodelling with histone H3 acetylation.
AB - Effects of all-trans retinoic acid (ATRA) on sphingomyelinase expression were examined using MCF-7 (ATRA-sensitive) and MDA-MB-231 (ATRA-resistant) breast cancer cells. Increased NSMase activity, NSMase2 mRNA and protein were observed in ATRA-treated MCF-7 but not in ATRA-treated MDA-MB-231. Increased NSMase2 mRNA of ATRA-treated MCF-7 was mostly due to enhanced transcription. Promoter analysis revealed the important 5′-promoter region of NSMase2 between -148 and -42 bp containing three Sp1 sites but no retinoic acid responsive elements. Experiments using mutated Sp1 sites of the NSMase2 promoter, Mithramycin A (a Sp inhibitor) and Sp family over-expression demonstrated the importance of Sp family protein and the three Sp1 sites for ATRA-induced NSMase2 transcription of MCF-7 cells. Although no quantitative change of bound Sp1 on NSMase2 promoter region after ATRA treatment was detected, Sp1 phosphorylation (activation) by ATRA was observed. Interestingly, PKCδ was involved in ATRA-induced increased NSMase2 transcription. ATRA-induced PKCδ phosphorylation and then activated PKCδ phosphorylated Sp1. Chromatin immunoprecipitation (ChIP) assay showed Sp1, RARα and RXRα complex formation in MCF-7 cells regardless of ATRA treatment and ATRA-induced acetylated histone H3 of the 5′-promoter. Thus, NSMase2 mRNA expression enhanced by ATRA was due to increased transcription via phosphorylated Sp1 caused by PKCδ activation, followed by chromatin remodelling with histone H3 acetylation.
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U2 - 10.1093/jb/mvs037
DO - 10.1093/jb/mvs037
M3 - Article
C2 - 22496486
AN - SCOPUS:84862275718
VL - 151
SP - 599
EP - 610
JO - Journal of Biochemistry
JF - Journal of Biochemistry
SN - 0021-924X
IS - 6
ER -