FoxP3 demethylation is increased in human colorectal cancer and rat cholangiocarcinoma tissue

Clin Biochem. 2014 Feb;47(3):201-5. doi: 10.1016/j.clinbiochem.2013.11.013. Epub 2013 Nov 26.

Abstract

Objectives: FoxP3 expression is a marker for Tregs which are known to be involved in tumor immunity. We aimed to evaluate FoxP3 promoter demethylation in human colorectal cancer (CRC) and rat intrahepatic cholangiocarcinoma (ICC).

Design and methods: Bisulfite-treated genomic DNA templates of shock frozen paired samples were studied from 13 anonymous CRC patients and from 10 male rats (n=6 ICC induced by thioacetamide and n=4 age-matched controls). Real-time PCR was carried out using a LightCycler 480 system. Human FoxP3 and CD3 promoter demethylations were estimated using previously described assays; and rat FoxP3 promoter demethylation using a newly developed assay.

Results: A significant 3.5-fold increase of the demethylation in FoxP3 promoter region was found in human CRC and rat ICC (P<0.05). The average frequency of cells with FoxP3 demethylation in patients suffering from CRC was 0.26% in normal tissue and 0.92% in tumor tissue (n=11 paired samples). Although, no significant difference was found between the mean frequency of CD3 demethylation in normal tissue (4.80%, n=6) and in tumor tissue (4.14%, n=6) from CRC patients, the ratio of demethylated CD3/FoxP3 promoter areas was significantly lower in tumor specimens (P<0.05). Using our novel assay, we found a significant increase in mean frequencies of cells with FoxP3 demethylation in rats with ICC (7.42%, n=6) in comparison to controls (2.14%, n=4).

Conclusion: FoxP3 seems to be an interesting biomarker for immune response to epithelial tumors. Functional consequences from the increase of Tregs remain to be demonstrated. Further studies with outcome data are necessary.

Keywords: CD3; Colorectal cancer (CRC); FoxP3; Intrahepatic cholangiocarcinoma (ICC); Promoter demethylation.

Publication types

  • Clinical Trial

MeSH terms

  • Adult
  • Aged
  • Animals
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / immunology
  • Biomarkers, Tumor / metabolism*
  • CD3 Complex / genetics
  • CD3 Complex / immunology
  • CD3 Complex / metabolism
  • Cholangiocarcinoma / genetics
  • Cholangiocarcinoma / immunology
  • Cholangiocarcinoma / metabolism*
  • Cholangiocarcinoma / pathology
  • Colorectal Neoplasms / genetics
  • Colorectal Neoplasms / immunology
  • Colorectal Neoplasms / metabolism*
  • Colorectal Neoplasms / pathology
  • DNA Methylation*
  • DNA, Neoplasm / genetics
  • DNA, Neoplasm / immunology
  • DNA, Neoplasm / metabolism*
  • Female
  • Forkhead Transcription Factors / genetics
  • Forkhead Transcription Factors / immunology
  • Forkhead Transcription Factors / metabolism*
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / immunology
  • Neoplasm Proteins / metabolism*
  • Promoter Regions, Genetic*
  • Rats
  • T-Lymphocytes, Regulatory / immunology
  • T-Lymphocytes, Regulatory / metabolism
  • T-Lymphocytes, Regulatory / pathology

Substances

  • Biomarkers, Tumor
  • CD3 Complex
  • DNA, Neoplasm
  • FOXP3 protein, human
  • Forkhead Transcription Factors
  • Foxp3 protein, rat
  • Neoplasm Proteins