title: Quantitative Histone Mass Spectrometry Identifies Elevated Histone H3 Lysine 27 (Lys27) Trimethylation in Melanoma.
abstract: Normal cell growth is characterized by a regulated epigenetic program that drives cellular activities such as gene transcription, DNA replication, and DNA damage repair. Perturbation of this epigenetic program can lead to events such as mis-regulation of gene transcription and diseases such as cancer. To begin to understand the epigenetic program correlated to the development of melanoma, we performed a novel quantitative mass spectrometric analysis of histone post-translational modifications mis-regulated in melanoma cell culture as well as patient tumors. Aggressive melanoma cell lines as well as metastatic melanoma were found to have elevated histone H3 Lys(27) trimethylation (H3K27me3) accompanied by overexpressed methyltransferase EZH2 that adds the specific modification. The altered epigenetic program that led to elevated H3K27me3 in melanoma cell culture was found to directly silence transcription of the tumor suppressor genes RUNX3 and E-cadherin. The EZH2-mediated silencing of RUNX3 and E-cadherin transcription was also validated in advanced stage human melanoma tissues. This is the first study focusing on the detailed epigenetic mechanisms leading to EZH2-mediated silencing of RUNX3 and E-cadherin tumor suppressors in melanoma. This study underscores the utility of using high resolution mass spectrometry to identify mis-regulated epigenetic programs in diseases such as cancer, which could ultimately lead to the identification of biological markers for diagnostic and prognostic applications.
authors.affiliation: From the ‡Department of Biochemistry and Molecular Biology.
authors.forename: Deepanwita
authors.initials: D
authors.lastname: Sengupta
authors.affiliation: From the ‡Department of Biochemistry and Molecular Biology.
authors.forename: Stephanie D
authors.initials: SD
authors.lastname: Byrum
authors.affiliation: From the ‡Department of Biochemistry and Molecular Biology.
authors.forename: Nathan L
authors.initials: NL
authors.lastname: Avaritt
authors.affiliation: From the ‡Department of Biochemistry and Molecular Biology.
authors.forename: Lauren
authors.initials: L
authors.lastname: Davis
authors.affiliation: From the ‡Department of Biochemistry and Molecular Biology.
authors.forename: Bradley
authors.initials: B
authors.lastname: Shields
authors.affiliation: ¶Department of Hematology Oncology and Internal Medicine, and.
authors.forename: Fade
authors.initials: F
authors.lastname: Mahmoud
authors.affiliation: From the ‡Department of Biochemistry and Molecular Biology.
authors.forename: Matthew
authors.initials: M
authors.lastname: Reynolds
authors.affiliation: From the ‡Department of Biochemistry and Molecular Biology.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Orr
authors.affiliation: From the ‡Department of Biochemistry and Molecular Biology.
authors.forename: Samuel G
authors.initials: SG
authors.lastname: Mackintosh
authors.affiliation: ‖Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205 ajtackett@uams.edu scshalin@uams.edu.
authors.forename: Sara C
authors.initials: SC
authors.lastname: Shalin
authors.affiliation: From the ‡Department of Biochemistry and Molecular Biology, ‖Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205 ajtackett@uams.edu scshalin@uams.edu.
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Tackett
mesh_terms: D015820:Cadherins / Q000235:genetics; D045744:Cell Line, Tumor; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics; D000071221:Enhancer of Zeste Homolog 2 Protein / Q000235:genetics; D044127:Epigenesis, Genetic; D015972:Gene Expression Regulation, Neoplastic; D006657:Histones / Q000378:metabolism*; D006801:Humans; D008239:Lysine / Q000378:metabolism*; D013058:Mass Spectrometry / Q000379:methods*; D008745:Methylation; D009101:Multiple Myeloma / Q000235:genetics / Q000378:metabolism*; D009362:Neoplasm Metastasis; D011499:Protein Processing, Post-Translational; D015854:Up-Regulation
chemical_list: D015820:Cadherins; D050659:Core Binding Factor Alpha 1 Subunit; D006657:Histones; C493709:RUNX2 protein, human; C498409:EZH2 protein, human; D000071221:Enhancer of Zeste Homolog 2 Protein; D008239:Lysine