title: A role of histone H4 hypoacetylation in vascular endothelial growth factor expression in colon mucosa adjacent to implanted cancer in athymic mice cecum.
abstract: Expression of angiogenic factors is upregulated in hyperplastic mucosa adjacent to colon cancer, and this upregulation is closely associated with cancer growth and metastasis. We investigated the role of histone acetylation in vascular endothelial growth factor (VEGF) expression in hyperplastic mucosa adjacent to orthotopic colon cancer in mice. In the hyperplastic mucosa adjacent to KM12SM tumor in the cecum of athymic mice, VEGF upregulation was associated with hypoxia-inducible factor (HIF)-1alpha induction. The hyperplastic mucosa also showed hypoacetylation of histone H4 and reduction of both p53 and von Hippel-Lindau (VHL) proteins. To examine the effects of growth factors and cytokines on histone acetylation and levels of p53, VHL and HIF-1alpha, the rat intestinal epithelial cell line IEC6 was treated with epidermal growth factor (EGF) and interleukin (IL)-15 for 35 days. Acetylated histone H4, p53 protein and ubiquitinated protein levels were reduced, whereas HIF-1alpha production was upregulated in EGF- and IL-15-treated IEC6 cells. These findings suggest that EGF- or IL-15-induced histone H4 hypoacetylation is associated with repression of p53 and VHL genes in intestinal epithelial cells. The subsequent suppression of protein ubiquitination leads to upregulation of VEGF production by HIF-1alpha retention.
authors.affiliation: Department of Oncological Pathology, Cancer Center, Nara Medical University, Kashihara, Japan. cooninh@zb4.so-net.ne.jp
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kuniyasu
authors.forename: Yoshitomo
authors.initials: Y
authors.lastname: Chihara
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kondo
mesh_terms: D000107:Acetylation; D000818:Animals; D045744:Cell Line, Tumor; D003106:Colon / Q000378:metabolism* / Q000473:pathology; D003110:Colonic Neoplasms / Q000473:pathology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D044127:Epigenesis, Genetic; D019084:Fluorescent Antibody Technique, Indirect; D006657:Histones / Q000378:metabolism*; D006801:Humans; D006965:Hyperplasia; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D019409:Interleukin-15 / Q000494:pharmacology; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D051381:Rats; D013047:Specific Pathogen-Free Organisms; D014157:Transcription Factors / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: C497442:HIF1A protein, human; D006657:Histones; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D019409:Interleukin-15; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D004815:Epidermal Growth Factor; D044767:Ubiquitin-Protein Ligases