Association between the combined effects of GSTM1 present/null and CYP1A1 MspI polymorphisms with lung cancer risk: an updated meta-analysis

Background: Many studies have been performed to explore the combined effects of glutathione-S-transferase M1 (GSTM1) present/null and cytochrome P4501A1 (CYP1A1) MspI polymorphisms with lung cancer (LC) risk, but the results are contradictory. Two previous meta-analyses have been reported on the issue in 2011 and 2014. However, several new articles since then have been published. In addition, their meta-analyses did not valuate the credibility of significantly positive results. Objectives: We performed an updated meta-analysis to solve the controversy following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Methods: False-positive report probability (FPRP), Bayesian false discovery probability (BFDP), and the Venice criteria were used to verify the credibility of meta-analyses. Results: Twenty-three publications including 5734 LC cases and 7066 controls met the inclusion criteria in the present study. A significantly increased risk of LC was found in overall analysis, Asians and Indians. However, all positive results were considered as ‘less-credible’ when we used the Venice criteria, FPRP, and BFDP test to assess the credibility of the positive results. Conclusion: These positive findings should be interpreted with caution and results indicate that significant associations may be less-credible, there are no significantly increased LC risk between the combined effects of GSTM1 present/null and CYP1A1 MspI polymorphisms.

Assessment of CYP1A1 (MspI) Gene Polymorphism in Patients with Chronic Obstructive Pulmonary Disease

Background Chronic obstructive pulmonary disease (COPD) is one of the most important causes of morbidity and mortality worldwide, characterized by persistent and progressive airflow limitations. The etiology seems to be an interaction between genetic and environmental factors. Objectives We aim in this present study to evaluate the role of Cytochrome P450 1A1 (CYP1A1 MspI) (3801 T/C) gene polymorphism in the development of Chronic Obstructive Pulmonary Disease ( COPD) by PCR-RFLP. Subjects and Methods Our study was performed on 50 subjects ( 35 COPD patients & 15 control ). Pulmonary function test was performed for patient group,DNA extraction was done and polymorphism was assayed for all participants by polymerase chain reaction-restriction fraction length polymorphism ( PCR-RFLP). Results We found that smoking rate among COPD patients was significantly higher than the control group ( P value = 0.003). The genotypic distribution of the single nucleotide polymorphisms (SNP) 3801 T/C did not differ significantly between patients and healthy controls (P value = 0.78).As regards disease severity , the genotype distribution was found to be significantly different between GOLD 1&2 and Gold 3&4 groups. Combined TC +CC alleles was found in 6 patients ( 100%) of Gold 3&4 ( P value<0.001) Conclusion Our study demonstrated that there is no relation between CYP1A1 gene polymorphism and development of COPD.It shows significant relation between COPD development and smoking, it also shows significant relation between MSPI gene polymorphism and disease severity regarding Gold staging and decline in lung function.