Human Colorectal Cancer Stage-dependent Global DNA Hypomethylation of Cancer-associated Fibroblasts

Anticancer Res. 2016 Sep;36(9):4503-7. doi: 10.21873/anticanres.10996.

Abstract

Background/aim: Cancer-associated fibroblasts (CAFs) play an important role in tumor development and progression. The prevailing consensus favors the view that a specific epigenetic signature underpins the stable CAF phenotype. The aim of the present study was to assess global DNA methylation in CAFs during the adenoma-carcinoma sequence in non-familial sporadic human colorectal cancer (CRC).

Patients and methods: Immunohistochemical staining of nuclear 5-methylcytosine (5'-meCyt) was performed in matched samples of colonic tumor tissue and normal colonic mucosa excised from six patients with adenomas and four with adenocarcinomas. The staining intensity was expressed semi-quantitatively as the immunohistochemical staining score (ISS).

Results: ISS values of human colonic CAFs and adenomatous samples were 14.00±2.2 and 14.08±1.8, respectively, showing no statistically significant difference. In contrast, a marked trend was found towards global DNA hypomethylation in CAFs from adenocarcinomatous specimens compared to matched normal mucosa: ISS: 9.25±2.44 (range=6-11) vs. 16.17±0.75, respectively, p<0.03.

Conclusion: Final stages of cancer development in CRC are associated with global DNA hypomethylation in stromal CAFs.

Keywords: Methylation; colorectal cancer; fibroblasts.

MeSH terms

  • Adenocarcinoma / metabolism*
  • Adenoma / embryology*
  • Biomarkers, Tumor / metabolism
  • Biopsy
  • Cancer-Associated Fibroblasts / metabolism*
  • Cell Line, Tumor
  • Colorectal Neoplasms / genetics*
  • Colorectal Neoplasms / metabolism*
  • DNA Methylation*
  • Epigenesis, Genetic
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Immunohistochemistry
  • Neoplasm Staging
  • Phenotype

Substances

  • Biomarkers, Tumor