title: Histone acetyltransferase MOZ acts as a co-activator of Nrf2-MafK and induces tumour marker gene expression during hepatocarcinogenesis.
abstract: HATs (histone acetyltransferases) contribute to the regulation of gene expression, and loss or dysregulation of these activities may link to tumorigenesis. Here, we demonstrate that expression levels of HATs, p300 and CBP [CREB (cAMP-response-element-binding protein)-binding protein] were decreased during chemical hepatocarcinogenesis, whereas expression of MOZ (monocytic leukaemia zinc-finger protein; MYST3)--a member of the MYST [MOZ, Ybf2/Sas3, Sas2 and TIP60 (Tat-interacting protein, 60 kDa)] acetyltransferase family--was induced. Although the MOZ gene frequently is rearranged in leukaemia, we were unable to detect MOZ rearrangement in livers with hyperplastic nodules. We examined the effect of MOZ on hepatocarcinogenic-specific gene expression. GSTP (glutathione S-transferase placental form) is a Phase II detoxification enzyme and a well-known tumour marker that is specifically elevated during hepatocarcinogenesis. GSTP gene activation is regulated mainly by the GPE1 (GSTP enhancer 1) enhancer element, which is recognized by the Nrf2 (nuclear factor-erythroid 2 p45 subunit-related factor 2)-MafK heterodimer. We found that MOZ enhances GSTP promoter activity through GPE1 and acts as a co-activator of the Nrf2-MafK heterodimer. Further, exogenous MOZ induced GSTP expression in rat hepatoma H4IIE cells. These results suggest that during early hepatocarcinogenesis, aberrantly expressed MOZ may induce GSTP expression through the Nrf2-mediated pathway.
authors.affiliation: Laboratory of Environmental Biochemistry, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-Oka, Suita, Osaka 565-0871, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Ohta
authors.forename: Megumi
authors.initials: M
authors.lastname: Ohigashi
authors.forename: Ayako
authors.initials: A
authors.lastname: Naganawa
authors.forename: Hiromi
authors.initials: H
authors.lastname: Ikeda
authors.forename: Masaharu
authors.initials: M
authors.lastname: Sakai
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Nishikawa
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Imagawa
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Osada
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nishihara
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor; D022762:CCAAT-Enhancer-Binding Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D019281:Dimerization; D015870:Gene Expression; D051549:Glutathione S-Transferase pi / Q000235:genetics / Q000378:metabolism; D051548:Histone Acetyltransferases / Q000235:genetics / Q000378:metabolism*; D008113:Liver Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology*; D050985:MafK Transcription Factor / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D051381:Rats
chemical_list: D014408:Biomarkers, Tumor; D022762:CCAAT-Enhancer-Binding Proteins; D050985:MafK Transcription Factor; D051267:NF-E2-Related Factor 2; D051548:Histone Acetyltransferases; C518073:Kat6a protein, rat; D051549:Glutathione S-Transferase pi