Risk Modulation of Oral Pre Cancer and Cancer with Polymorphisms in XPD and XPG Genes in North Indian Population

Document Type: Research Articles

Authors

1 Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow Campus, Lucknow, Uttar Pradesh, India.

2 Department of Oral Pathology and Microbiology, King George's Medical University, Lucknow, Uttar Pradesh, India.

3 Department of Radiotherapy, King George’s Medical University, Lucknow, Uttar Pradesh, India.

Abstract

Background: Environmental carcinogens cause DNA damages which if not repaired properly, may increase the
risk of cancer. The Xerodermapigmentosum group D (XPD) and group G (XPG) genes are essential genes for DNA
repair and alteration in DNA repair causes cancer. The present study aimed to evaluate the relationship between XPD
and XPG polymorphisms and risk of oral pre cancer and cancer. Methods: Present study genotyped 302 samples of
oral diseases and 300 controls for XPD (A/C) and XPG (G/C) polymorphisms with PCR-RFLP method. Results: Our
result showed that compared to AA genotype frequency of AC and CC genotype for XPD(A/C) polymorphism were
significantly lower among cases than in control and are associated with decreased risk of oral diseases (OR= 0.621
and 0.603 respectively). In contrast with reference to GG genotype the frequency of CC genotype of XPG (G/C) was
significantly higher in case than in control population (p value=0.004) and found to increase the risk of oral diseases
(OR= 2.077). Particularly C allele for XPD A/C polymorphism was found to be associated with decreased risk of Lichen
planus and increased risk of ( OR = 0.470 and 1.541 respectively) oral cancer. While C allele of XPG G/C polymorphism
significantly increased the risk of Oral Submucous Fibrosis and Leukoplakia (OR= 1.879 and 1.837 respectively) but
not of Lichen planus and oral cancer. In combined genotype analysis from the aforesaid polymorphisms presence of C
allele for XPD (A/C) polymorphisms were found to decrease the risk of oral diseases. However, the same C allele was
observed to increase the chance of having high stage disease (OR= 5.71) with nodal involvement (OR= 6.78) once the
cancer been initiated. Conclusion: This work shows association of XPD (A/C), XPG (G/C) polymorphisms with the
development of pre oral cancer as well as oral cancer and its clinical courses.

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