title: Histone H3 lysine 27 acetylation is altered in colon cancer.
abstract: BACKGROUND
  Histone post-translational modifications (PTMs) play an important role in the regulation of the expression of genes, including those involved in cancer development and progression. However, our knowledge of PTM patterns in human tumours is limited.
  
  
  METHODS
  MS-based analyses were used to quantify global alterations of histone PTMs in colorectal cancer (CRC) samples. Histones isolated from 12 CRCs and their corresponding normal mucosa by acidic extraction were separated by SDS-PAGE and analysed by liquid chromatography-mass spectrometry.
  
  
  RESULTS
  Among 96 modified peptides, 41 distinct PTM sites were identified, of which 7, 13, 11, and 10 were located within the H2A, H2B, H3, and H4 sequences, respectively, and distributed among the amino-terminal tails and the globular domain of the four histones. Modification intensities were quantified for 33 sites, of which 4 showed significant (p-value ≤ 0.05) differences between CRC tissues and healthy mucosa samples. We identified histone H3 lysine 27 acetylation (H3K27Ac) as a modification upregulated in CRC, which had not been shown previously.
  
  
  CONCLUSIONS
  The present results indicate the usefulness of a bottom-up proteomic approach for the detection of histone modifications at a global scale. The differential abundance of H3K27Ac mark in CRC, a PTM associated with active enhancers, suggests its role in regulating genes whose expression changes in CRC.
authors.affiliation: Department of Genetics, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw 02-781, Poland.
authors.forename: Jakub
authors.initials: J
authors.lastname: Karczmarski
authors.affiliation: Institute of Radioelectronics, Warsaw University of Technology, Warsaw 00-665, Poland.
authors.forename: Tymon
authors.initials: T
authors.lastname: Rubel
authors.affiliation: Department of Gastroenterology and Hepatology, Medical Center for Postgraduate Education, Warsaw 01-813, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Paziewska
authors.affiliation: Department of Genetics, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw 02-781, Poland.
authors.forename: Michal
authors.initials: M
authors.lastname: Mikula
authors.affiliation: Department of Molecular and Translational Oncology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw 02-781, Poland.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Bujko
authors.affiliation: Department of Molecular and Translational Oncology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw 02-781, Poland.
authors.forename: Paulina
authors.initials: P
authors.lastname: Kober
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw 02-106, Poland.
authors.forename: Michal
authors.initials: M
authors.lastname: Dadlez
authors.affiliation: Department of Genetics, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw 02-781, Poland ; Department of Gastroenterology and Hepatology, Medical Center for Postgraduate Education, Warsaw 01-813, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Ostrowski
keywords: Acetylation; Colorectal cancer; Histone; LC-MS