Biological significance of 5-hydroxymethylcytosine in oral epithelial dysplasia and oral squamous cell carcinoma

Oral Surg Oral Med Oral Pathol Oral Radiol. 2018 Jan;125(1):59-73.e2. doi: 10.1016/j.oooo.2017.06.006. Epub 2017 Jun 16.

Abstract

Objectives: The aim of this study was to determine the levels of 5-hydroxylmethylcytosine (5-hmC) in oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC) compared with those in benign, reactive inflammatory lesions and to explore whether DNA hydroxymethylation may serve as a novel biomarker for early diagnosis and prognosis of OSCC.

Study design: The study included normal mucosa from uninvolved margins of 9 fibromas, 10 oral lichen planus, 15 OED, and 23 OSCC. Cultured human keratinocyte lines from benign oral mucosa, OED, and OSCC, as well as a murine model in which OSCC was induced with 4-nitroquinoline-1-oxide, were also evaluated.

Results: Progressive loss of 5-hmC from benign oral mucosal lesions to OED and OSCC was documented in patient samples. Decreased levels in 5-hmC that typify OED and OSCC were also detectable in human cell lines. Moreover, we characterized similar alterations in 5-hmC in an animal model of OED/OSCC.

Conclusions: This study demonstrated that 5-hmC distinguishes OED and OSCC from benign lesions with high sensitivity and specificity. Consequently, loss of 5-hmC may be useful for the diagnosis of OED with potential implications for therapy of OSCC.

MeSH terms

  • 5-Methylcytosine / analogs & derivatives*
  • 5-Methylcytosine / metabolism
  • Animals
  • Biomarkers, Tumor
  • Carcinoma, Squamous Cell / metabolism*
  • Carcinoma, Squamous Cell / pathology
  • Cells, Cultured
  • DNA Methylation
  • Disease Models, Animal
  • Early Diagnosis
  • Fibroma / metabolism
  • Humans
  • Immunoblotting
  • Immunoenzyme Techniques
  • Keratinocytes / metabolism
  • Lichen Planus, Oral / metabolism
  • Mice
  • Mouth Neoplasms / metabolism*
  • Mouth Neoplasms / pathology
  • Precancerous Conditions / metabolism*
  • Precancerous Conditions / pathology
  • Prognosis

Substances

  • Biomarkers, Tumor
  • 5-hydroxymethylcytosine
  • 5-Methylcytosine