title: Array-based identification of common DNA methylation alterations in             ulcerative colitis.
abstract: Patients with long-standing ulcerative colitis (UC) have higher risk of developing colorectal cancer. Albeit the causes remain to be understood, epigenetic alterations have been suggested to play a role in the long-term cancer risk of these patients. In this work, we developed a novel microarray platform based on methylation-sensitive amplified fragment length polymorphism (MS-AFLP) DNA fingerprinting. The over 10,000 NotI sites of the human genome were used to generate synthetic primers covering these loci that are equally distributed into CpG rich regions (promoters and CpG islands) and outside the CpG islands, providing a panoramic view of the methylation alterations in the genome. The arrays were first tested using the colon cancer cell line CW-2 showing the reproducibility and sensitivity of the approach. We next investigated DNA methylation alterations in the colonic mucosa of 14 UC patients. We identified epigenetic alterations affecting genes putatively involved in UC disease, and in susceptibility to develop colorectal cancer. There was a strong concordance of methylation alterations (both hypermethylation and hypomethylation) shared by the cancer cells of the CW-2 cell line and the non-cancer UC samples. To the best of our knowledge, this work defines the first high-throughput aberrant DNA methylation profiles of the colonic mucosa of UC patients. These epigenetic profiles provide novel and relevant knowledge on the molecular alterations associated to the UC pathology. Some of the detected alterations could be exploited as cancer risk predictors underlying a field defect for cancerization in UC-associated carcinogenesis.
authors.affiliation: First Department of Surgery, Hamamatsu University School of Medicine,                     1-20-1 Handa-yama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Koizumi
authors.forename: Sergio
authors.initials: S
authors.lastname: Alonso
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Miyaki
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Okada
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ogura
authors.forename: Norihiko
authors.initials: N
authors.lastname: Shiiya
authors.forename: Fumio
authors.initials: F
authors.lastname: Konishi
authors.forename: Toshiki
authors.initials: T
authors.lastname: Taya
authors.forename: Manuel
authors.initials: M
authors.lastname: Perucho
authors.forename: Koichi
authors.initials: K
authors.lastname: Suzuki
mesh_terms: D000328:Adult; D000368:Aged; D054458:Amplified Fragment Length Polymorphism Analysis / Q000379:methods*; D045744:Cell Line, Tumor; D003093:Colitis, Ulcerative / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D003110:Colonic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D019175:DNA Methylation; D057890:Epigenomics; D005260:Female; D006801:Humans; D008297:Male; D046228:Microarray Analysis; D008875:Middle Aged; D012307:Risk Factors; D055815:Young Adult