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Article: Regulation of the human secretin gene is controlled by the combined effects of CpG methylation, Sp1/Sp3 ratio, and the E-box element

TitleRegulation of the human secretin gene is controlled by the combined effects of CpG methylation, Sp1/Sp3 ratio, and the E-box element
Authors
Issue Date2004
PublisherEndocrine Society. The Journal's web site is located at http://mend.endojournals.org/
Citation
Molecular Endocrinology, 2004, v. 18 n. 7, p. 1740-1755 How to Cite?
AbstractTo unravel the mechanisms that regulate the human secretin gene expression, in this study, we have used secretin-expressing (HuTu-80 cells, human duodenal adenocarcinoma) and non-secretin-expressing [PANC-1 (human pancreatic ductile carcinoma) and HepG2 (human hepatocellular carcinoma) cells] cell models for in vitro and in vivo analyses. By transient transfection assays, within the promoter region (-11 to -341 from ATG, relative to the ATG initiation codon), we have initially identified several functional motifs including an E-box and 2 GC-boxes. Results from gel mobility shift and chromatin immunoprecipitation assays confirmed further that NeuroD, E2A, Sp1, and Sp3 bind to these E- and GC-boxes in HuTu-80 cells in vitro and in vivo, whereas only high levels of Sp3 is observed to bind the promoter in HepG2 cells. In addition, overexpression of Sp3 resulted in a dose-dependent repression of the Sp1-mediated transactivation. Collectively, these data suggest that the Sp1/Sp3 ratio is instrumental to controlling secretin gene expression in secretin-producing and non-secretin-producing cells. The functions of GC-box and Sp proteins prompted us to investigate the possible involvement of DMA methylation in regulating this gene. Consistent with this idea, we found a putative CpG island (-336 to 262 from ATG) that overlaps with the human secretin gene promoter. By methylation-specific PCR, all the CpG dinucleo-tides (26 of them) within the CpG island in HuTu-80 cells are unmethylated, whereas all these sites are methylated in PANC-1 and HepG2 cells. The expressions of secretin in PANC-1 and HepG2 cells were subsequently found to be significantly activated by a demethylation agent, 5′-Aza-2′ deoxycytidine. Taken together, our data indicate that the human secretin gene is controlled by the in vivo Sp1/Sp3 ratio and the methylation status of the promoter.
Persistent Identifierhttp://hdl.handle.net/10722/84737
ISSN
2015 Impact Factor: 3.432
2015 SCImago Journal Rankings: 2.195
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorLee, LTOen_HK
dc.contributor.authorTanUn, KCen_HK
dc.contributor.authorPang, RTKen_HK
dc.contributor.authorLam, DTWen_HK
dc.contributor.authorChow, BKCen_HK
dc.date.accessioned2010-09-06T08:56:32Z-
dc.date.available2010-09-06T08:56:32Z-
dc.date.issued2004en_HK
dc.identifier.citationMolecular Endocrinology, 2004, v. 18 n. 7, p. 1740-1755en_HK
dc.identifier.issn0888-8809en_HK
dc.identifier.urihttp://hdl.handle.net/10722/84737-
dc.description.abstractTo unravel the mechanisms that regulate the human secretin gene expression, in this study, we have used secretin-expressing (HuTu-80 cells, human duodenal adenocarcinoma) and non-secretin-expressing [PANC-1 (human pancreatic ductile carcinoma) and HepG2 (human hepatocellular carcinoma) cells] cell models for in vitro and in vivo analyses. By transient transfection assays, within the promoter region (-11 to -341 from ATG, relative to the ATG initiation codon), we have initially identified several functional motifs including an E-box and 2 GC-boxes. Results from gel mobility shift and chromatin immunoprecipitation assays confirmed further that NeuroD, E2A, Sp1, and Sp3 bind to these E- and GC-boxes in HuTu-80 cells in vitro and in vivo, whereas only high levels of Sp3 is observed to bind the promoter in HepG2 cells. In addition, overexpression of Sp3 resulted in a dose-dependent repression of the Sp1-mediated transactivation. Collectively, these data suggest that the Sp1/Sp3 ratio is instrumental to controlling secretin gene expression in secretin-producing and non-secretin-producing cells. The functions of GC-box and Sp proteins prompted us to investigate the possible involvement of DMA methylation in regulating this gene. Consistent with this idea, we found a putative CpG island (-336 to 262 from ATG) that overlaps with the human secretin gene promoter. By methylation-specific PCR, all the CpG dinucleo-tides (26 of them) within the CpG island in HuTu-80 cells are unmethylated, whereas all these sites are methylated in PANC-1 and HepG2 cells. The expressions of secretin in PANC-1 and HepG2 cells were subsequently found to be significantly activated by a demethylation agent, 5′-Aza-2′ deoxycytidine. Taken together, our data indicate that the human secretin gene is controlled by the in vivo Sp1/Sp3 ratio and the methylation status of the promoter.en_HK
dc.languageengen_HK
dc.publisherEndocrine Society. The Journal's web site is located at http://mend.endojournals.org/en_HK
dc.relation.ispartofMolecular Endocrinologyen_HK
dc.rightsMolecular Endocrinology. Copyright © The Endocrine Society.en_HK
dc.titleRegulation of the human secretin gene is controlled by the combined effects of CpG methylation, Sp1/Sp3 ratio, and the E-box elementen_HK
dc.typeArticleen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=0888-8809&volume=18&spage=1740&epage=1755&date=2004&atitle=Regulation+of+the+Human+Secretin+Gene+is+Controlled+by+the+Combined+Effects+of+CpG+Methylation,+Sp1/Sp3+Ratio,+and+the+E-Box+Elementen_HK
dc.identifier.emailLee, LTO: ltolee2@hkucc.hku.hken_HK
dc.identifier.emailTanUn, KC: kctanun@hkucc.hku.hken_HK
dc.identifier.emailPang, RTK: rtkpang@hku.hken_HK
dc.identifier.emailChow, BKC: bkcc@hku.hken_HK
dc.identifier.authorityLee, LTO=rp00727en_HK
dc.identifier.authorityTanUn, KC=rp00787en_HK
dc.identifier.authorityPang, RTK=rp01761en_HK
dc.identifier.authorityChow, BKC=rp00681en_HK
dc.description.naturelink_to_subscribed_fulltext-
dc.identifier.doi10.1210/me.2003-0461en_HK
dc.identifier.pmid15118068-
dc.identifier.scopuseid_2-s2.0-3042788955en_HK
dc.identifier.hkuros91133en_HK
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-3042788955&selection=ref&src=s&origin=recordpageen_HK
dc.identifier.volume18en_HK
dc.identifier.issue7en_HK
dc.identifier.spage1740en_HK
dc.identifier.epage1755en_HK
dc.identifier.isiWOS:000222259000013-
dc.publisher.placeUnited Statesen_HK
dc.identifier.scopusauthoridLee, LTO=8367269000en_HK
dc.identifier.scopusauthoridTanUn, KC=6602914262en_HK
dc.identifier.scopusauthoridPang, RTK=7004376636en_HK
dc.identifier.scopusauthoridLam, DTW=11840131300en_HK
dc.identifier.scopusauthoridChow, BKC=7102826193en_HK

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