Association between environmental tobacco smoke exposure and lung cancer susceptibility: Modification by antioxidant enzymes genetic polymorphisms

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• 作者：Wafa Ashour ; Mona Fathy ; Mai Hamed ; Omnia Youssif ; Nahla Fawzy
• 关键词：Environmental tobacco smoke ; Lung cancer ; Antioxidant enzymes
• 刊名：Egyptian Journal of Chest Diseases and Tuberculosis
• 出版年：October, 2013
• 年：2013
• 卷：62
• 期：4
• 页码：781-788
• 全文大小：431 K

文摘

Background

Environmental tobacco smoke (ETS) is the primary etiological factor of lung cancer. However, only 10-15% of smokers develop lung cancer, suggesting genetic role in modifying individual susceptibility to lung cancer. Antioxidant enzyme functional genetic polymorphisms should be considered.

Aim of the work

The present study aimed to evaluate the role of antioxidant enzyme activity and genetic polymorphisms in modifying the susceptibility to lung cancer among individuals exposed to ETS.

Subjects and methods

A total of 150 male subjects were divided into three groups: 50 lung cancer patients, 50 chronic smokers and 50 passive smokers. Genotyping of mEH exon 3 (Tyr¹¹³Hist) and exon 4 (Hist¹³⁹Arg) polymorphisms was done by PCR-RFLP technique. MnSOD (Val¹⁶Ala) polymorphism was detected by Real time-TaqMan assay. Erythrocyte MnSOD activity was measured spectrophotometrically.

Results

ETS exposed individuals (both active and passive smokers) who carried His allele of mEH exon3 have 2.9-folds increased risk of lung cancer (rong class="boldFont">OR 2.9 P < 0.001)rong>. Also ETS exposed carriers of Arg allele of mEH exon 4 have 2.1-folds higher risk to lung cancer rong class="boldFont">(OR 2.1 P = 0.024)rong>. However no association between MnSOD Val¹⁶Ala polymorphism and lung cancer was detected among ETS rong class="boldFont">(OR 1.6 P = 0.147),rong> although lung cancer group had significantly lower MnSOD activity than chronic or passive smokers groups rong class="boldFont">(P = 0.03)rong>.

Conclusion

Exons 3 and 4 polymorphisms of the mEH gene may contribute to lung cancer susceptibility through disturbed antioxidant balance. However, this was not the case with MnSOD Val¹⁶Ala SNP. Antioxidant enzymes may modulate the influence of ETS exposure on lung cancer risk.