title: Immunohistochemical analysis of the DNA methyltransferase 3b expression is associated with significant improvements in the discrimination of ulcerative colitis-associated neoplastic lesions.
abstract: OBJECTIVE
  Making a clinicopathological diagnosis of dysplasia is crucial. We herein assess the significance of the DNA methyltransferase 3b (DNMT3b) expression as a diagnostic marker of ulcerative colitis (UC)-associated neoplasia.
  
  
  METHODS
  Thirty-one patients with long-standing and extensive UC were included in this study. The expression of DNMT3b in non-neoplastic rectal epithelium (non-dysplasia in 31 patients) and colorectal neoplasia (dysplasia in 43 patients and invasive cancer in 34 patients) was determined using immunohistochemistry. The presence of immunoreactive DNMT3b was assessed in the areas with the highest density of cells with positively staining nuclei. DNMT3b was expressed as the percentage of positive cells relative to the total number of cells counted under high power magnification.
  
  
  RESULTS
  The DNMT3b expression in neoplastic rectal epithelium (0.76, range 0.59-0.84) was increased compared to that observed in non-neoplastic epithelium (0.32, range 0.18-0.67, P < 0.001). A ROC curve analysis confirmed 0.68 to be the best diagnostic cut-off value for the DNMT3b expression in neoplastic epithelium (area under the curve = 0.810). The sensitivity of the diagnostic test was 66.2 %, the specificity was 86.7 %, the positive predictive value was 95.7 % and the negative predictive value was 36.1 %. The positive likelihood ratio was 4.98 and the negative likelihood ratio was 0.20. The accuracy was 69.9 %.
  
  
  CONCLUSIONS
  An immunohistochemical analysis of the DNMT3b expression was associated with significant improvements in the discrimination of UC-associated neoplastic lesions.
authors.affiliation: Department of Surgical and Molecular Pathology, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Shimotsuga, Tochigi, 321-0292, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Ueda
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Ichikawa
authors.forename: Michio
authors.initials: M
authors.lastname: Itabashi
authors.forename: Shingo
authors.initials: S
authors.lastname: Kameoka
authors.forename: Shigehiko
authors.initials: S
authors.lastname: Fujii
authors.forename: Natsuko
authors.initials: N
authors.lastname: Saito
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Kimura
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Shida
authors.forename: Yukari
authors.initials: Y
authors.lastname: Fujimori
authors.forename: Shinichirou
authors.initials: S
authors.lastname: Ohtake
authors.forename: Shigeki
authors.initials: S
authors.lastname: Tomita
authors.forename: Johji
authors.initials: J
authors.lastname: Imura
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Yasuda
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Tanigawa
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Uchiyama
authors.forename: Takahiro
authors.initials: T
authors.lastname: Fujimori
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D003093:Colitis, Ulcerative / Q000150:complications / Q000175:diagnosis*; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000209:etiology; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000032:analysis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008875:Middle Aged; D000097584:DNA Methyltransferase 3B
chemical_list: D015415:Biomarkers; D004248:DNA (Cytosine-5-)-Methyltransferases; D000097584:DNA Methyltransferase 3B