Association between XRCC1 and XRCC3 Polymorphisms with Lung Cancer Risk: A Meta-Analysis from Case-Control Studies

<div><p>Many studies have reported the association of X-ray repair cross-complementing group 1 (<i>XRCC1</i>) Arg399Gln, Arg194Trp, Arg280His, −77T>C, and X-ray repair cross-complementing group 3 (<i>XRCC3</i>) T241M polymorphisms with lung cancer risk, but the results remained controversial. Hence, we performed a meta-analysis to investigate the association between lung cancer risk and <i>XRCC1</i> Arg399Gln (14,156 cases and 16,667 controls from 41 studies), Arg194Trp (7,426 cases and 9,603 controls from 23 studies), Arg280His (6,211 cases and 6,763 controls from 16 studies), −77T>C (2,487 cases and 2,576 controls from 5 studies), and <i>XRCC3</i> T241M (8,560 cases and 11,557 controls from 19 studies) in different inheritance models. We found that −77T>C polymorphism was associated with increased lung cancer risk (dominant model: odds ration [OR] = 1.45, 95% confidence interval [CI] = 1.27–1.66, recessive model: OR = 1.73, 95% CI = 1.14–2.62, additive model: OR = 1.91, 95% CI = 1.24–1.94) when all the eligible studies were pooled into the meta-analysis. In the stratified and sensitive analyses, significantly decreased lung cancer risk was observed in overall analysis (dominant model: OR = 0.83, 95% CI = 0.78–0.89; recessive model: OR = 0.90, 95% CI = 0.81–1.00; additive model: OR = 0.82, 95% CI = 0.74–0.92), Caucasians (dominant model: OR = 0.82, 95% CI = 0.76–0.87; recessive model: OR = 0.89, 95% CI = 0.80–0.99; additive model: OR = 0.81, 95% CI = 0.73–0.91), and hospital-based controls (dominant model: OR = 0.81, 95% CI = 0.76–0.88; recessive model: OR = 0.89, 95% CI = 0.79–1.00; additive model: OR = 0.80, 95% CI = 0.71–0.90) for <i>XRCC3</i> T241M. In conclusion, this meta-analysis indicates that <i>XRCC1</i> −77T>C shows an increased lung cancer risk and <i>XRCC3</i> T241M polymorphism is associated with decreased lung cancer risk, especially in Caucasians.</p></div

Results of meta-analysis for XRCC1 and XRCC3 polymorphisms and lung cancer risk.

<p>AC Adenocarcinoma, SC Squamous cell carcinoma, SCLC Small cell lung cancer,</p>*<p>Random-effect model was used when <i>P</i> value of heterogeneity test (<i>P</i>_h)<0.10; otherwise, fixed-effect model was used.</p

Association between β2-Adrenoceptor Gene Polymorphisms and Asthma Risk: An Updated Meta-Analysis

<div><p>Background</p><p>Evidence is increasingly accumulated about multiple roles for the β2-adrenoceptor gene in asthma. The results were inconsistent partly due to small sample sizes. To assess the association between β2-adrenoceptor gene polymorphisms and asthma risk, a meta-analysis was performed.</p><p>Methods</p><p>We comprehensively searched the PubMed, EMBASE, BIOSIS Previews databases and extracted data from all eligible articles to estimate the association between β2-adrenoceptor gene polymorphisms and asthma risk. The pooled odds ratio (OR) with 95% confidence intervals (CIs) were calculated.</p><p>Results</p><p>Thirty-seven studies involving 6648 asthma patients and 15943 controls were included in the meta-analysis. Overall, significant associations were found in allelic genetic model (OR = 1.06, 95% CI = 1.01∼1.12), recessive genetic model (OR = 1.11, 95% CI = 1.02∼1.21) for Arg/Gly16. Stratified by ethnicity and age, significant associations were also found in Asian population in allelic genetic model, recessive genetic model and addictive model. For Gln/Glu27, no significant association was found when we combined all eligible studies. Age stratification showed significant associations in adults in allelic genetic model and recessive genetic model, but no significant association was found among Asians and Caucasians in ethnicity stratification.</p><p>Conclusions</p><p>This meta-analysis implied that the β2-adrenoceptor Arg/Gly16 polymorphism was likely to contribute to asthma risk in Asian population. Gln/Glu27 polymorphism might be a contributor to asthma susceptibility for adults.</p></div

Forest plot of XRCC1 −77T>C polymorphism and lung cancer risk (additive model).

<p>Forest plot of XRCC1 −77T>C polymorphism and lung cancer risk (additive model).</p

Galbraith plots of the association between β2AR Arg16Gly polymorphism and asthma.

<p>A) Asian population subgroup; B) caucasian population subgroup. Four studies# maybe the main contributors to the heterogeneity Asian population subgroup; One studies# maybe the main contributors to the heterogeneity Asian population subgroup.</p

Results of the pooled analyses and subgroup analyses for the β2AR Arg/Gly16 polymorphism and asthma risk.

<p>n, number of studies.</p

Results of the pooled analyses and subgroup analyses for the β2AR Gln/Glu27 polymorphism and asthma risk.

<p># Pooled result not included study of Santilan, A A#, n, number of studies.</p

Main characteristics of all studies included in the meta-analysis.

<p>SNPS Single-nucleotide polymorphism studied, GM Genotyping method, SC Source of controls, SSCP Single-strand conformation polymorphism, CTPP Contronting two-pair primers, SNPS Single-nucleotide polymorphism studied, PB Population-based study, HB Hospital-based study.</p

Forest plot of XRCC1 −77T>C polymorphism and lung cancer risk (dominant model).

<p>Forest plot of XRCC1 −77T>C polymorphism and lung cancer risk (dominant model).</p

The Duval and Tweedie nonparametric “trim and fill” method's funnel plot funnel plot of the meta-analysis of lung cancer risk and XRCC3 T241M polymorphism (dominant model and additive model).

<p>The Duval and Tweedie nonparametric “trim and fill” method's funnel plot funnel plot of the meta-analysis of lung cancer risk and XRCC3 T241M polymorphism (dominant model and additive model).</p