Skip to main content
SpringerLink
Log in

DNA methylation and expression of the folate transporter genes in colorectal cancer

  • Research Article
  • Published:
Tumor Biology

Abstract

Folate has a central role in the cell metabolism. This study aims to explore the DNA methylation pattern of the folate transporter genes FOLR1, PCFT, and RFC1 as well as the corresponding protein expressions in colorectal cancer (CRC) tissue and adjacent non-cancerous mucosa (ANCM). Our results showed statistically significant differences in the DNA-methylated fraction of all three genes at several gene regions; we identified three differentially methylated CpG sites in the FOLR1 gene, five CpG sites in the PCFT gene, and six CpG sites in the RFC1 gene. There was a pronounced expression of the FRα and RFC proteins in both the CRC and ANCM tissues, though the expression was attenuated in cancer compared to the paired ANCM tissues. The PCFT protein was undetectable or expressed at a very low level in both tissue types. Higher methylated fractions of the CpG sites 3–5 in the RFC1 gene were associated with a lower protein expression, suggestive of epigenetic regulation by DNA methylation of the RFC1 gene in the colorectal cancer. Our results did not show any association between the RFC and FRα protein expression and tumor stage, TNM classification, or tumor location. In conclusion, this is the first study to simultaneously evaluate both DNA methylation and protein expression of all three folate transporter genes, FOLR1, PCFT, and RFC1, in colorectal cancer. The results encourage further investigation into the possible prognostic implications of folate transporter expression and DNA methylation.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5

Similar content being viewed by others

Abbreviations

CRC:

colorectal cancer

FOLR1 :

folate receptor 1

RFC1 :

reduced folate carrier

PCFT :

proton coupled folate transporter

References

  1. Jemal A et al. Global Cancer Statistics. CA Cancer J Clin. 2011;61(2):69–90.

    Article  PubMed  Google Scholar 

  2. Al-Sohaily S et al. Molecular pathways in colorectal cancer. J Gastroenterol Hepatol. 2012;27(9):1423–31.

    Article  CAS  PubMed  Google Scholar 

  3. Jass JR. Classification of colorectal cancer based on correlation of clinical, morphological and molecular features. Histopathology. 2007;50(1):113–30.

    Article  CAS  PubMed  Google Scholar 

  4. Stover PJ, Field MS. Trafficking of intracellular folates. Adv Nutr (Bethesda, Md). 2011;2(4):325–31.

    Article  CAS  Google Scholar 

  5. Liu M et al. Structure and regulation of the murine reduced folate carrier gene: identification of four noncoding exons and promoters and regulation by dietary folates. J Biol Chem. 2005;280(7):5588–97.

    Article  CAS  PubMed  Google Scholar 

  6. Qiu A et al. Rodent intestinal folate transporters (SLC46A1): secondary structure, functional properties, and response to dietary folate restriction. Am J Physiol Cell Physiol. 2007;293(5):C1669–78.

    Article  CAS  PubMed  Google Scholar 

  7. Shia J et al. Immunohistochemical expression of folate receptor alpha in colorectal carcinoma: patterns and biological significance. Hum Pathol. 2008;39(4):498–505.

    Article  CAS  PubMed  Google Scholar 

  8. Kelemen LE. The role of folate receptor alpha in cancer development, progression and treatment: cause, consequence or innocent bystander? Int J Cancer. 2006;119(2):243–50.

    Article  CAS  PubMed  Google Scholar 

  9. Teng L, Xie J, Lee RJ. Clinical translation of folate receptor-targeted therapeutics. Expert Opin Drug Deliv. 2012;9(8):901–8.

    Article  CAS  PubMed  Google Scholar 

  10. Ly A et al. Folate and DNA methylation. Antioxid Redox Signal. 2012;17(2):302–26.

    Article  CAS  PubMed  Google Scholar 

  11. Kim YI. Nutritional epigenetics: impact of folate deficiency on DNA methylation and colon cancer susceptibility. J Nutr. 2005;135(11):2703–9.

    CAS  PubMed  Google Scholar 

  12. Duthie SJ et al. Impact of folate deficiency on DNA stability. J Nutr. 2002;132(8):2444S–9S.

    CAS  PubMed  Google Scholar 

  13. Farkas SA et al. Epigenetic alterations in folate transport genes in placental tissue from fetuses with neural tube defects and in leukocytes from subjects with hyperhomocysteinemia. Epigenetics. 2013;8(3):303–16.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  14. Tiernan JP et al. Carcinoembryonic antigen is the preferred biomarker for in vivo colorectal cancer targeting. Br J Cancer. 2013;108(3):662–7.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  15. Parker N et al. Folate receptor expression in carcinomas and normal tissues determined by a quantitative radioligand binding assay. Anal Biochem. 2005;338(2):284–93.

    Article  CAS  PubMed  Google Scholar 

  16. Shia, J., et al., Immunohistochemical expression of folate receptor a in colorectal carcinoma: patterns and biological significance. Hum Pathol, 2008;39(4).

  17. Whetstine JR, Flatley RM, Matherly LH. The human reduced folate carrier gene is ubiquitously and differentially expressed in normal human tissues: identification of seven non-coding exons and characterization of a novel promoter. Biochem J. 2002;367:629–40.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. Nunez MI et al. High expression of folate receptor alpha in lung cancer correlates with adenocarcinoma histology and EGFR [corrected] mutation. J Thorac Oncol. 2012;7(5):833–40.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  19. Iwakiri S et al. Expression status of folate receptor alpha is significantly correlated with prognosis in non-small-cell lung cancers. Ann Surg Oncol. 2008;15(3):889–99.

    Article  PubMed  Google Scholar 

  20. Chen YL et al. Serous ovarian carcinoma patients with high alpha-folate receptor had reducing survival and cytotoxic chemo-response. Mol Oncol. 2012;6(3):360–9.

    Article  CAS  PubMed  Google Scholar 

  21. Brown Jones M et al. Rationale for folate receptor alpha targeted therapy in "high risk" endometrial carcinomas. Int J Cancer. 2008;123(7):1699–703.

    Article  PubMed  Google Scholar 

  22. Qiu A et al. Identification of an intestinal folate transporter and the molecular basis for hereditary folate malabsorption. Cell. 2006;127(5):917–28.

    Article  CAS  PubMed  Google Scholar 

  23. Luo Y, Yu M, Grady WM. Field cancerization in the colon: a role for aberrant DNA methylation? Gastroenterol Rep (Oxf). 2014;2(1):16–20.

    Article  Google Scholar 

  24. Taby R, Issa JP. Cancer epigenetics. CA Cancer J Clin. 2010;60(6):376–92.

    Article  PubMed  Google Scholar 

  25. De Bustos C et al. Tissue-specific variation in DNA methylation levels along human chromosome 1. Epigenetics Chromatin. 2009;2(1):7.

    Article  PubMed  PubMed Central  Google Scholar 

  26. Doi A et al. Differential methylation of tissue- and cancer-specific CpG island shores distinguishes human induced pluripotent stem cells, embryonic stem cells and fibroblasts. Nat Genet. 2009;41(12):1350–3.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  27. Irizarry R et al. The human colon cancer methylome shows similar hypo- and hypermethylation at conserved tissue-specific CpG island shores. Nat Genet. 2009;41(2):178–86.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Liu MJ et al. Transcriptional regulation of the human reduced folate carrier in childhood acute lymphoblastic leukemia cells. Clin Cancer Res. 2006;12(2):608–16.

    Article  CAS  PubMed  Google Scholar 

  29. Rothem L et al. Reduced folate carrier gene silencing in multiple antifolate-resistant tumor cell lines is due to a simultaneous loss of function of multiple transcription factors but not promoter methylation. J Biol Chem. 2004;279(1):374–84.

    Article  CAS  PubMed  Google Scholar 

  30. Kastrup IB et al. Genetic and epigenetic alterations of the reduced folate carrier in untreated diffuse large B-cell lymphoma. Eur J Haematol. 2008;80(1):61–6.

    CAS  PubMed  Google Scholar 

  31. Worm J et al. Methylation-dependent silencing of the reduced folate carrier gene in inherently methotrexate-resistant human breast cancer cells. J Biol Chem. 2001;276(43):39990–40000.

    Article  CAS  PubMed  Google Scholar 

  32. Ferreri AJ et al. Aberrant methylation in the promoter region of the reduced folate carrier gene is a potential mechanism of resistance to methotrexate in primary central nervous system lymphomas. Br J Haematol. 2004;126(5):657–64.

    Article  CAS  PubMed  Google Scholar 

  33. Gonen N, Bram EE, Assaraf YG. PCFT/SLC46A1 promoter methylation and restoration of gene expression in human leukemia cells. Biochem Biophys Res Commun. 2008;376(4):787–92.

    Article  CAS  PubMed  Google Scholar 

  34. Diop-Bove NK et al. Hypermethylation of the human proton-coupled folate transporter (SLC46A1) minimal trancriptional regulatory region in an antifolate-resistant HeLa cell line. Mol Cancer Ther. 2009;8(8):2424–31.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  35. Kulis M et al. Intragenic DNA methylation in transcriptional regulation, normal differentiation and cancer. Biochim Biophys Acta. 2013;1829(11):1161–74.

    Article  CAS  PubMed  Google Scholar 

  36. Hsueh CT, Dolnick BJ. Regulation of folate-binding protein gene expression by DNA methylation in methotrexate-resistant KB cells. Biochem Pharmacol. 1994;47(6):1019–27.

    Article  CAS  PubMed  Google Scholar 

  37. Lind GE et al. Identification of an epigenetic biomarker panel with high sensitivity and specificity for colorectal cancer and adenomas. Mol Cancer. 2011;10.

  38. Wettergren Y et al. p16INK4a gene promoter hypermethylation in mucosa as a prognostic factor for patients with colorectal cancer. Mol Med. 2008;14(7–8):412–21.

    CAS  PubMed  PubMed Central  Google Scholar 

  39. Kawakami K et al. Low expression of gamma-glutamyl hydrolase mRNA in primary colorectal cancer with the CpG island methylator phenotype. Br J Cancer. 2008;98(9):1555–61.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgments

This work was supported by Lions Cancer Foundation, Nyckelfonden, and the Research committee of Örebro county council.

Conflicts of interest

None

Author information

Authors and Affiliations

  1. Department of Laboratory Medicine, Faculty of Medicine and Health, Örebro University, SE-701 82, Örebro, Sweden

    Sanja A. Farkas, Rahel Befekadu & Victoria Hahn-Strömberg

  2. Department of Medical Biosciences, Clinical Chemistry, Umeå University, Umeå, Sweden

    Torbjörn K. Nilsson

Authors
  1. Sanja A. Farkas
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Rahel Befekadu
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Victoria Hahn-Strömberg
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Torbjörn K. Nilsson
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Sanja A. Farkas.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Farkas, S.A., Befekadu, R., Hahn-Strömberg, V. et al. DNA methylation and expression of the folate transporter genes in colorectal cancer. Tumor Biol. 36, 5581–5590 (2015). https://doi.org/10.1007/s13277-015-3228-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s13277-015-3228-2

Keywords

Search

Navigation