Skip to main content
Log in

EPHX1 gene polymorphisms among south Indian populations

  • Original Paper
  • Published:
Molecular & Cellular Toxicology Aims and scope Submit manuscript

Abstract

Microsomal epoxide hydrolase is a smooth endoplasmic reticulum enzyme and is expressed relatively ubiquitously in most tissues and in many species. The microsomal epoxide hydrolase (mEH) encoded by EPHX1 is a biotransformation enzyme that metabolizes numerous reactive epoxide intermediates to more water-soluble trans-dihydrodiol derivatives. In the present study, we genotyped two SNPs of the EPHX1 gene [(Exon 3: Tyr113His; rs1051740) and (Exon 4: His139 Arg; rs2234922)], using TaqMan allelic discrimination among 212 individuals of six major south Indian populations, and compared with other available world populations data. Both polymorphisms followed Hardy-Weinberg equilibrium and were highly polymorphic in the studied populations. The haplotype based analysis revealed remarkable variation among the study populations. Linkage disequilibrium (LD) between Tyr113 His and His139Arg loci was not significant in any of the population studied. Calculation of LD in the 20kb up and downstream regions from Tyr113His and His 139Arg loci in HapMap populations revealed no significant LD between these markers in all the populations. Analysis of predicted EPHX1 activity status of all samples revealed that the prevalence of low activity samples is more than the intermediate and high activity samples in all populations studied. Screening of additional populations and computation of genetic distances between populations at SNP sites may help in understanding the population genetic and evolutionary aspects of this gene.

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

Access this article

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

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Decker, M., Arand, M. & Cronin, A. Mammalian epoxide hydrolases in xenobiotic metabolism and signalling. Arch Toxicol 83:297–318 (2009).

    Article  PubMed  CAS  Google Scholar 

  2. Coller, J. K. et al. Distribution of microsomal epoxide hydrolase in humans: an immunohistochemical study in normal tissues, and benign and malignant tumours. Histochem J 33:329–336 (2001).

    Article  PubMed  CAS  Google Scholar 

  3. Taura Ki K. et al. Activation of microsomal epoxide hydrolase by interaction with cytochromes P450: kinetic analysis of the association and substrate-specific activation of epoxide hydrolase function. Arch Biochem Biophys 402:275–280 (2002).

    Article  PubMed  Google Scholar 

  4. Shou, M., Gonzalez, F. J. & Gelboin, H. V. Stereoselective epoxidation and hydration at the K-region of polycyclic aromatic hydrocarbons by cDNA-expressed cytochromes P450 1A1, 1A2, and epoxide hydrolase. Biochemistry 35:15807–15813 (1996).

    Article  PubMed  CAS  Google Scholar 

  5. Hassett, C., Robinson, K. B., Beck, N. B. & Omiecinski, C. J. The human microsomal epoxide hydrolase gene (EPHX1): complete nucleotide sequence and structural characterization. Genomics 23:433–442 (1994).

    Article  PubMed  CAS  Google Scholar 

  6. Liang, S. H., Hassett, C. & Omiecinski, C. J. Alternative promoters determine tissue-specific expression profiles of the human microsomal epoxide hydrolase gene (EPHX1). Mol Pharmacol 67:220–230 (2005).

    Article  PubMed  CAS  Google Scholar 

  7. Omiecinski, C. J., Aicher, L., Holubkov, R. & Checkoway, H. Human peripheral lymphocytes as indicators of microsomal epoxide hydrolase activity in liver and lung. Pharmacogenetics 3:150–158 (1993).

    Article  PubMed  CAS  Google Scholar 

  8. Zhu, Q. S., Qian, B. & Levy, D. Regulation of human microsomal epoxide hydrolase gene (EPHX1) expression by the transcription factor GATA-4. Biochim Biophys Acta 1676:251–260 (2004).

    Article  PubMed  CAS  Google Scholar 

  9. Zhu, Q. S., Qian, B. & Levy, D. CCAAT/enhancerbinding protein alpha (C/EBPalpha) activates transcription of the human microsomal epoxide hydrolase gene (EPHX1) through the interaction with DNA-bound NF-Y. J Biol Chem 279:29902–29910 (2004).

    Article  PubMed  CAS  Google Scholar 

  10. Hartsfield, J. K., Jr. et al. Assignment1 of microsomal epoxide hydrolase (EPHX1) to human chromosome 1q42.1 by in situ hybridization. Cytogenet Cell Genet 83:44–45 (1998).

    Article  PubMed  CAS  Google Scholar 

  11. Hassett, C., Aicher, L., Sidhu, J. S. & Omiecinski, C. J. Human microsomal epoxide hydrolase: genetic polymorphism and functional expression in vitro of amino acid variants. Hum Mol Genet 3:421–428 (1994).

    Article  PubMed  CAS  Google Scholar 

  12. Benhamou, S., Reinikainen, M., Bouchardy, C., Dayer, P. & Hirvonen, A. Association between lung cancer and microsomal epoxide hydrolase genotypes. Cancer Res 58:5291–5293 (1998).

    PubMed  CAS  Google Scholar 

  13. Smith, C. A. & Harrison, D. J. Association between polymorphism in gene for microsomal epoxide hydrolase and susceptibility to emphysema. Lancet 350:630–633 (1997).

    Article  PubMed  CAS  Google Scholar 

  14. Curtis, L. R., Hemmer, M. J. & Courtney, L. A. Dieldrin induces cytosolic [3H]7, 12-dimethylbenz[a]anth racene binding but not multidrug resistance proteins in rainbow trout liver. J Toxicol Environ Health A 60: 275–289 (2000).

    Article  PubMed  CAS  Google Scholar 

  15. Mukherjee, J. J., Kumar, S., Gocinski, R. & Williams, J. Phenolic fraction of tobacco smoke inhibits BPDEinduced apoptosis response and potentiates cell transformation: role of attenuation of p53 response. Chem Res Toxicol 24:698–705 (2011).

    Article  PubMed  CAS  Google Scholar 

  16. Bhaskar, L. V. et al. EPHX1 Gene Polymorphisms in Alcohol Dependence and their Distribution among the Indian Populations. Am J Drug Alcohol Abuse (2012).

    Google Scholar 

  17. Cortessis, V. et al. A case-control study of microsomal epoxide hydrolase, smoking, meat consumption, glutathione S-transferase M3, and risk of colorectal adenomas. Cancer Res 61:2381–2385 (2001).

    PubMed  CAS  Google Scholar 

  18. Ma, M. et al. Influence of genetic polymorphisms of styrene-metabolizing enzymes and smoking habits on levels of urinary metabolites after occupational exposure to styrene. Toxicol Lett 160:84–91 (2005).

    Article  PubMed  CAS  Google Scholar 

  19. Ada, A. O., Suzen, H. S. & Iscan, M. Polymorphisms of microsomal epoxide hydrolase and glutathione Stransferase P1 in a male Turkish population. Int J Toxicol 26:41–46 (2007).

    Article  PubMed  CAS  Google Scholar 

  20. Voho, A. et al. EPHX1 gene polymorphisms and individual susceptibility to lung cancer. Cancer Lett 237: 102–108 (2006).

    Article  PubMed  CAS  Google Scholar 

  21. Robien, K. et al. Microsomal epoxide hydrolase polymorphisms are not associated with colon cancer risk. Cancer Epidemiol Biomarkers Prev 14:1350–1352 (2005).

    Article  PubMed  CAS  Google Scholar 

  22. Wu, X. et al. The association of microsomal epoxide hydrolase polymorphisms and lung cancer risk in African-Americans and Mexican-Americans. Carcinogenesis 22:923–928 (2001).

    Article  PubMed  CAS  Google Scholar 

  23. Li, X. et al. Putative EPHX1 enzyme activity is related with risk of lung and upper aerodigestive tract cancers: a comprehensive meta-analysis. PLoS One 6: e14749 (2011).

    Article  PubMed  CAS  Google Scholar 

  24. Liu, F. et al. Systematic Review and Meta-Analysis of the Relationship between EPHX1 Polymorphisms and Colorectal Cancer Risk. PLoS One 7:e43821 (2012).

    Article  PubMed  CAS  Google Scholar 

  25. Kiran, M., Chawla, Y. K., Jain, M. & Kaur, J. Haplotypes of microsomal epoxide hydrolase and x-ray crosscomplementing group 1 genes in Indian hepatocellular carcinoma patients. DNA Cell Biol 28:573–577 (2009).

    Article  PubMed  CAS  Google Scholar 

  26. Yang, X. et al. The expression of human microsomal epoxide hydrolase is predominantly driven by a genetically polymorphic far upstream promoter. J Pharmacol Exp Ther 330:23–30 (2009).

    Article  PubMed  CAS  Google Scholar 

  27. Sambrook, J., Fitsch, E. F. & Maniatis, T. Molecular Cloning: A Laboratory Manual. Cold Spring Harbor: Cold Spring Harbor Press 1989).

    Google Scholar 

  28. Cubells, J. F. et al. Population genetics of a functional variant of the dopamine beta-hydroxylase gene (DBH). Am J Med Genet 74:374–379 (1997).

    Article  PubMed  CAS  Google Scholar 

  29. Schneider, S., Roessli, D. & Excoffier, L. Arlequin v. 2.0: a software for population genetics data analysis. Geneva, Switzerland: Genetics and Biometry Laboratory, University of Geneva (2000).

    Google Scholar 

  30. Barrett, J. C., Fry, B., Maller, J. & Daly, M. J. Haploview: analysis and visualization of LD and haplotype maps. Bioinformatics 21:263–265 (2005).

    Article  PubMed  CAS  Google Scholar 

  31. Tanaka, T. [HapMap project]. Nihon Rinsho 67:1068–1071 (2009).

    PubMed  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Rajasekhar Maram.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Lakkakula, S., Maram, R., Munirajan, A.K. et al. EPHX1 gene polymorphisms among south Indian populations. Mol. Cell. Toxicol. 9, 219–225 (2013). https://doi.org/10.1007/s13273-013-0028-x

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s13273-013-0028-x

Keywords

Navigation