ATM polymorphisms and risk of lung cancer among never smokers. Lung Cancer. 2010;69:148-154. [PMID: 20004998 DOI: 10.1016/j.lungcan.2009.11.007]

Somatic and germline ATM variants in non-small-cell lung cancer: Therapeutic implications

ATM is an apical kinase of the DNA damage response involved in the repair of DNA double-strand breaks. Germline ATM variants (gATM) have been associated with an increased risk of developing lung adenocarcinoma (LUAD), and approximately 9% of LUAD tumors harbor somatic ATM mutations (sATM). Biallelic carriers of pathogenic gATM exhibit a plethora of immunological abnormalities, but few studies have evaluated the contribution of immune dysfunction to lung cancer susceptibility. Indeed, little is known about the clinicopathological characteristics of lung cancer patients with sATM or gATM alterations. The introduction of targeted therapies and immunotherapies, and the increasing number of clinical trials evaluating treatment combinations, warrants a careful reexamination of the benefits and harms that different therapeutic approaches have had in lung cancer patients with sATM or gATM. This review will discuss the role of ATM in the pathogenesis of lung cancer, highlighting potential therapeutic approaches to manage ATM-deficient lung cancers.

Next-generation universal hereditary cancer screening: implementation of an automated hereditary cancer screening program for patients with advanced cancer undergoing tumor sequencing in a large HMO

Variants in hereditary cancer risk genes are frequently identified following tumor-based DNA sequencing and represent an opportunity to diagnose hereditary cancer. We implemented an automated hereditary cancer screening program in a large HMO for all patients who underwent tumor-based DNA sequencing to identify patients with hereditary cancer and determine if this approach augmented existing genetic counseling approaches driven by personal/family history criteria. Regular automated searches of a centralized tumor DNA variant database were performed for ATM, BRCA1, BRCA2, MLH1, MSH2, MSH6, PALB2, and/or PMS2 variants, and germline hereditary cancer gene panel testing was offered to patients with tumor variants who had never undergone germline testing. Patients completing germline testing due to their tumor DNA test results were considered part of the tumor DNA safety net. Patients previously completing germline testing via traditional genetic counseling and tumor DNA safety net were compared for demographics, tumor type, presence of germline pathogenic/likely pathogenic (P/LP) variant, and whether NCCN criteria were met for hereditary cancer genetic testing. Germline P/LP variants were common in both groups. Patients who received germline testing through traditional genetic counseling were more likely to have cardinal hereditary tumors than the tumor DNA safety net group. Patients identified with hereditary cancer through traditional genetic counseling were more likely to meet NCCN personal/family history criteria for germline testing than the tumor DNA safety net group (99% versus 34%). A universal tumor DNA safety net screen is an important diagnostic strategy which augments traditional genetic counseling approaches based on personal/family history.

Rare deleterious germline variants and risk of lung cancer

Recent studies suggest that rare variants exhibit stronger effect sizes and might play a crucial role in the etiology of lung cancers (LC). Whole exome plus targeted sequencing of germline DNA was performed on 1045 LC cases and 885 controls in the discovery set. To unveil the inherited causal variants, we focused on rare and predicted deleterious variants and small indels enriched in cases or controls. Promising candidates were further validated in a series of 26,803 LCs and 555,107 controls. During discovery, we identified 25 rare deleterious variants associated with LC susceptibility, including 13 reported in ClinVar. Of the five validated candidates, we discovered two pathogenic variants in known LC susceptibility loci, ATM p.V2716A (Odds Ratio [OR] 19.55, 95%CI 5.04-75.6) and MPZL2 p.I24M frameshift deletion (OR 3.88, 95%CI 1.71-8.8); and three in novel LC susceptibility genes, POMC c.*28delT at 3' UTR (OR 4.33, 95%CI 2.03-9.24), STAU2 p.N364M frameshift deletion (OR 4.48, 95%CI 1.73-11.55), and MLNR p.Q334V frameshift deletion (OR 2.69, 95%CI 1.33-5.43). The potential cancer-promoting role of selected candidate genes and variants was further supported by endogenous DNA damage assays. Our analyses led to the identification of new rare deleterious variants with LC susceptibility. However, in-depth mechanistic studies are still needed to evaluate the pathogenic effects of these specific alleles.

The most frequent Polish ATM mutations are not susceptibility factors for tobacco-related cancers

INTRODUCTION

The inactivation of both alleles of the ATM gene leads to ataxia-telangiectasia syndrome, whereas carriers of monoallelic mutations in the ATM gene are associated with increased risk of different types of cancer. Three substitutions in the ATM gene (c.6095G>A, c.7630-2A>C, c.5932G>T) are the most common mutations causing ataxia-telangiectasia among Polish patients. The aim of this study was to determine whether these ATM mutations are associated with increased risk of tobacco-related cancers.

MATERIAL AND METHODS

783 Polish patients with tobacco-related cancers were included in the study (468 with lung cancer, 153 with a single laryngeal cancer, 86 with multiple primary tumors localized in the larynx and 76 multiple primary tumors localized in the head or neck). The control group consisted of 464 healthy subjects from the Polish population. Three ATM mutations - c.5932G>T, c.6095G>A, c.7630-2A>C - were tested among selected patients. Molecular analyses were performed using high resolution melting analysis and restriction fragment length polymorphism.

RESULTS

In the present study, we detected only one mutation, c.7630-2A>C, and no carriers of c.5932G>T, c.6095G>A mutations in the ATM gene among Polish patients with tobacco-related cancers. A patient with c.7630-2A>C mutation was diagnosed with lung adenocarcinoma, the most common type of lung cancer. One carrier of c.6095G>A mutation was found in the control group.

CONCLUSIONS

The results indicate that the studied ATM variants do not seem to be associated with tobacco-related cancers in Poland.

Inherited Rare, Deleterious Variants in ATM Increase Lung Adenocarcinoma Risk

INTRODUCTION

Lung cancer is the leading cause of cancer deaths in the world, and lung adenocarcinoma (LUAD) is its most prevalent subtype. Symptoms are often found in advanced disease in which treatment options are limited. Identifying genetic risk factors will enable better identification of high-risk individuals.

METHODS

To identify LUAD risk genes, we performed a case-control association study for gene-level burden of rare, deleterious variants (RDVs) in germline whole-exome sequencing data of 1083 patients with LUAD and 7650 controls, split into discovery and validation cohorts. Of these, we performed whole-exome sequencing on 97 patients and acquired the rest from multiple public databases. We annotated all rare variants for pathogenicity conservatively, using the guidelines of the American College of Medical Genetics and Genomics and ClinVar curation, and investigated gene-level RDV burden using penalized logistic regression. All statistical tests were two-sided.

RESULTS

We discovered and replicated the finding that the burden of germline ATM RDVs was significantly higher in patients with LUAD versus controls (combined cohort OR = 4.6; p = 1.7e-04; 95% confidence interval = 2.2-9.5; 1.21% of cases; 0.24% of controls). Germline ATM RDVs were also enriched in an independent clinical cohort of 1594 patients from the MSK-IMPACT study (0.63%). In addition, we observed that an Ashkenazi Jewish (AJ) founder ATM variant, rs56009889, was statistically significantly more frequent in AJ cases versus AJ controls in our cohort (combined AJ cohort OR = 2.7, p = 6.9e-03, 95% confidence interval = 1.3-5.3).

CONCLUSIONS

Our results indicate that ATM is a moderate-penetrance LUAD risk gene and that LUAD may be a part of the ATM-related cancer syndrome spectrum. Individuals with ATM RDVs are at an elevated LUAD risk and can benefit from increased surveillance (particularly computed tomography scanning), early detection, and chemoprevention programs, improving prognosis.

ATM gene polymorphisms are associated with poor prognosis of non-small cell lung cancer receiving radiation therapy

We investigated the prognostic significance of ataxia telangiectasia mutated (ATM) single nucleotide polymorphisms (SNPs) in 720 Han Chinese non-small cell lung cancer (NSCLC) patients who underwent radiation or chemoradiation therapy. Kaplan-Meier survival curves showed that overall survival (OS) and disease-free survival (DFS) rates were significantly associated with two ATM SNPs, rs664143 and rs189037. Patients with the rs664143 GA or AA genotype had poorer DFS (hazard ratio (HR) = 1.40, 95% confidence interval (CI) = 1.05-1.86, P = 0.021) and OS (HR = 1.28, 95%CI = 1.12-1.78, P = 0.040) than those with the rs664143 GG phenotype. Patients with the rs189037 AG/GG genotypes had poorer prognoses than those with the rs189037 AA genotype (AG/GG vs. AA: DFS, HR = 1.44, 95%CI = 1.06-1.95, P=0.019; OS, HR = 1.16, 95%CI = 1.16-1.17-2.21, P=0.004). These results were confirmed by subgroup analysis based on clinical factors such as smoking, histology, tumor stage, treatment, and radiation dose, all of which were significantly associated with DFS and OS rates in NSCLC patients. These findings show that ATM rs664143 and rs189037 variants determine prognosis in NSCLC patients that have undergone radiation or chemoradiation therapies.

The ATM rs189037 G>A polymorphism is associated with the risk and prognosis of gastric cancer in Chinese individuals: A case-control study

The ataxia telangiectasia mutated (ATM) gene is involved in repairing DNA lesions and maintaining genome stability, which is related to cancer invasion and metastasis. This gene influences the risk of cancers. Many studies have demonstrated that the ATM rs189037 G>A polymorphism is linked with the risks of different types of cancer. However, no study has probed the relationship between the ATM rs189037 G>A polymorphism and gastric cancer (GC) risk. Therefore, the aims of this study were to investigate the association of the ATM rs189037 G>A polymorphism with the risk and prognosis of GC in a case-control investigation of 345 GC patients and 467 controls in China. The rs189037 G>A polymorphism was genotyped using polymerase chain reaction-restriction fragment length polymorphism. This polymorphism was related to a significantly higher risk of GC [AA vs. GG: OR (95% CI): 1.80 (1.20-2.70), P = 0.04; GG vs. AA + GA: 1.46 (1.08-1.98); A vs. G: 1.34 (1.10-1.64), P = 0.004]. Subgroup analyses showed significant associations with female gender, smoking, alcohol consumption, age ≥60 years, and positive Helicobacter pylori status. This polymorphism was also correlated with TNM stage III + IV and tumor size >4 cm. GC patients carrying the AA genotype of the rs189037 polymorphism also had lower overall survival. In conclusion, the ATM rs189037 G>A polymorphism was related to increased susceptibility to and poorer prognosis in GC in this Chinese population.

Polymorphisms and rare variants identified by next-generation sequencing confer risk for lung cancer in han Chinese population

BACKGROUND

Lung cancer is one of the leading causes of cancer death worldwide, and genetic risk factors account for a large part of its carcinogenesis. The low economic requirements and high efficiency of next-generation sequencing (NGS) make it widely used in detecting genetic alterations in pathogenesis.

METHODS

We performed targeted panel sequencing in 780 Han Chinese lung cancer patients using a commercial probe, and the correlations between dozens of susceptible sites were verified in 1113 healthy controls. This study used Fisher's exact test and Benjamini-Hochberg FDR correction to analyze the mutual exclusion between mutated genes, and Pearson's p was used to verify the correlations between mutations and lung cancer susceptibility.

RESULTS

Our results determined the mutation spectrum and showed that each lung cancer patient carried at least one DNA mutation. The most frequently mutated gene was BRCA2 (mutation rate,10.6 %.). The co-occurrence and mutual exclusion analysis of DNA damage related genes showed that gene ATM was mutually exclusive from MSH6. We conducted a further case-control study in different subtypes of lung cancer and the results described 14 mutations associated with adenocarcinoma, 9 with squamous cell carcinoma, and 4 with small cell lung cancer. These variants were novel de-novo germline mutations in lung cancer. Particularly, rs3864017 in FANCD2 showed a protective effect of lung adenocarcinoma for carriers (OR = 0.146, 95 % CI = 0.052∼0.405, P_adjusted = 3.37 × 10^-4).

CONCLUSIONS

18 candidate mutations might alter the risk of lung cancer in the Han Chinese population, including polymorphisms rs3864017(FANCD2), rs55740729(MSH6) and 16 rare variants. The underlying mechanisms of candidate genes in lung cancer remain unclear and we suggest more functional studies on exploring how these genes affect the risk of lung cancer.

Association of two BRM promoter polymorphisms and smoking status with malignant pleural mesothelioma risk and prognosis

Brahma (BRM), of the SWI/SNF complex, has two 6 to 7 bp insertion promoter polymorphisms (BRM-741/BRM-1321) that cause epigenetic BRM suppression, and are associated with risk of multiple cancers. BRM polymorphisms were genotyped in malignant pleural mesothelioma (MPM) cases and asbestos-exposed controls. Multivariable logistic regression (risk) and Cox regression (prognosis) were performed, including stratified analyses by smoking status to investigate the effect of polymorphisms on MPM risk and prognosis. Although there was no significant association overall between BRM-741/BRM-1321 and risk in patients with MPM, a differential effect by smoking status was observed (P-interaction < .001), where homozygous variants were protective (aOR of 0.18-0.28) in ever smokers, while never smokers had increased risk when carrying homozygous variants (aOR of 2.7-4.4). While there was no association between BRM polymorphisms and OS in ever-smokers, the aHR of carrying homozygous-variants of BRM-741, BRM-1321 or both were 4.0 to 8.6 in never-smokers when compared to wild-type carriers. Mechanistically, lower mRNA expression of BRM was associated with poorer general cancer prognosis. Electrophoretic mobility shift assays and chromatin immunoprecipitation experiments (ChIP) revealed high BRM insertion variant homology to MEF2 regulatory binding sites. ChIP experimentation confirmed MEF2 binding only occurs in the presence of insertion variants. DNA-affinity purification assays revealed YWHA scaffold proteins as vital to BRM mRNA expression. Never-smokers who carry BRM homozygous variants have an increased chance of developing MPM, which results in worse prognosis. In contrast, in ever-smokers, there may be a protective effect, with no difference in overall survival. Mechanisms for the interaction between BRM and smoking require further study.

ATM rs189037 significantly increases the risk of cancer in non-smokers rather than smokers: an updated meta-analysis

Rs189037 (G>A) is an important functional variant with ataxia telangiectasia mutated (ATM) gene, which might affect ATM’s expression involvement in several human cancers. Increasing evidence reveals that smoking-related cancers have distinct molecular characteristics from non-smoking cancers. Until now, the role of ATM rs189037 in cancer risk stratified by smoking status still remains unclear. To evaluate the association between ATM rs189037 and cancer risk based on smoking status, we performed this meta-analysis by a comprehensive literature search via databases of PubMed, Embase, Web of Science and CNKI, updated till January 2019. Multivariate-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were extracted from eligible studies if available, to assess the relationship strengths. A total of seven eligible studies were included, comprising 4294 cancer patients (smokers: 1744 [40.6%]) and 4259 controls (smokers: 1418 [33.3%]). Results indicated a significant association of ATM rs189037 with cancer risk. In non-smokers, compared with GG genotype, AA genotype increased a 1.40-fold risk of overall cancer (OR = 1.40, 95% CI = 1.15–1.70, P_{heterogeneity}=0.433, I² = 0.0%). Subgroup analysis in lung cancer (LC) also exhibited a significant result (OR = 1.41, 95% CI = 1.15–1.73, P_{heterogeneity}=0.306, I² = 17.0%) only in non-smokers. However, the association was not observed in smokers, no matter for overall cancer or for LC. Our findings highlight that ATM rs189037 significantly increases cancer susceptibility in non-smokers, rather than in smokers. The association is prominent in LC.

ATM rs189037 (G > A) polymorphism increased the risk of cancer: an updated meta-analysis

BACKGROUND

Rs189037 (G > A) is a functional single nucleotide polymorphism (SNP) in the Ataxia-telangiectasia mutated (ATM) gene that may be associated with the risk of cancer. We performed a meta-analysis to determine whether rs189037 polymorphism influences the occurrence of cancer and examined the relationship between this SNP and the etiology of cancer.

METHODS

Case-control studies were retrieved from literature databases in accordance with established inclusion criteria. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the strength of the association between rs189037 and cancer. Subgroup analysis and sensitivity analysis also were performed.

RESULTS

After inclusion criteria were met, fifteen studies-comprising 8660 patients with cancer (cases) and 9259 controls-were included in this meta-analysis. Summary results indicated that an association was found between rs189037 and cancer risk. In the dominant model, the pooled OR using a random effects model was 1.207 (95% CI, 1.090-1.337; P < 0.001). The A allele of rs189037 increased the risk of lung cancer, breast cancer, and oral cancer. Results of subgroup analysis by ethnicity indicated that the SNP was associated with the risk of cancer among East Asian and Latino, but not Caucasian.

CONCLUSIONS

Results of this meta-analysis suggest that rs189037 is associated with the occurrence of lung cancer, breast cancer, and oral cancer as the risk factor. These data provide possible avenues for future case-control studies related to cancer.

Targeted next generation sequencing identified a high frequency genetic mutated profile in wood smoke exposure-related lung adenocarcinoma patients

BACKGROUND

Wood smoke exposure (WSE) has been associated with an increased risk of lung cancer development. WSE has been related with high frequency of EGFR mutations and low frequency of KRAS mutations. The aim of this study was to evaluate large scale genomic alterations in lung adenocarcinomas associated with WSE using targeted next generation sequencing.

METHODS

DNA multi-targeted sequencing was performed in 42 fresh-frozen samples of advanced lung adenocarcinomas. The TruSeQ Cancer Panel (Illumina) was used for genomic library construction and sequencing assays.

RESULTS

WSE rate was higher in women (p=0.037) and non-smokers (p=0.001). WSE correlated with mutations in the genes SMARCB1 (p=0.002), Ataxia telangiectasia mutated (p=0.004), Kinase Insert Domain Receptor (p=0.006), and were borderline significant in RET and EGFR exon. Genomic alterations significantly co-occurred in the tumor suppressor gene ATM with the following genes: SMARCB1, EGFR exon 7, RET and KDR. Clinical factors associated with poor prognosis were ECOG ≥ 2 (p= 0.014), mutations in KDR (p= 0.004) and APC genes (p < 0.001).

CONCLUSIONS

Lung adenocarcinoma patients with WSE showed a distinctive mutated profile for the SMARCB1, ATM, EGFR exon 7, RET and KDR genes. ECOG status and KDR gene mutations were significantly associated with poor prognosis.

Association between ATM gene polymorphisms, lung cancer susceptibility and radiation-induced pneumonitis: a meta-analysis

BACKGROUND

Previous studies have suggested that DNA double-strand break (DSB) repair is an important protective pathway after damage. The ataxia telangiectasia mutated (ATM) gene plays an important role in the DNA DSB repair pathway. DNA damage is a major cytotoxic effect that can be caused by radiation, and the ability to repair DNA after damage varies among different tissues. Impaired DNA repair pathways are associated with high sensitivity to radiation exposure. Hence, ATM gene polymorphisms are thought to influence the risk of cancer and radiation-induced pneumonitis (RP) risk in cancer patients treated with radiotherapy. However, the results of previous studies are inconsistent. We therefore conducted this comprehensive meta-analysis.

METHODS

A systematic literature search was performed in the PubMed, Embase, China National Knowledge Internet (CNKI) and Wanfang databases to identify studies that investigated the association between the ATM gene polymorphisms and both lung cancer and RP radiotherapy-treated lung cancer (the last search was conducted on Dec.10, 2015). The odds ratio (OR) and 95% confidence interval (CI) were used to investigate the strength of these relationships. Funnel plots and Begg's and Egger's tests were conducted to assess the publication bias. All analyses were performed in STATA 13.0 software.

RESULTS

Ten eligible case-control studies (4731 cases and 5142 controls) on lung cancer susceptibility and four (192 cases and 772 controls) on RP risk were included. The results of the overall and subgroup analyses indicated that in the ATM gene, the rs189037 (-111G > A, -4519G > A), rs664677 (44831C > T, 49238C > T) and rs664143 (131,717 T > G) polymorphisms were significantly associated with lung cancer susceptibility (OR = 1.21, 95% CI = 1.04-1.39, P = 0.01; OR = 1.26, 95% CI = 1.06-1.49, P = 0.01; OR = 1.43, 95% CI = 1.15-1.78, P < 0.01). Additionally, the rs189037 variant was significantly associated with RP risk (OR = 1.74, 95% CI = 1.02-2.97, P = 0.04). No publication bias was found in the funnel plots, Begg's tests or Egger's tests.

CONCLUSIONS

The results indicate that the ATM rs189037, rs664677 and rs664143 gene polymorphisms are risk factors for lung cancer, while the ATM rs189037 variant was significantly associated with RP risk.

Genetic predisposition to lung adenocarcinoma among never-smoking Chinese with different epidermal growth factor receptor mutation status

OBJECTIVES

The inconsistent findings from genetic association studies may be related to the heterogeneity in different molecular subtypes of lung cancer. This study evaluated the predisposing single-nucleotide polymorphisms (SNPs) in epidermal growth factor receptor (EGFR) mutant and EGFR wild-type lung adenocarcinoma separately among never-smokers.

MATERIALS AND METHODS

This was a two-stage case-control study. Never-smokers with pathologically confirmed lung adenocarcinoma and healthy controls were recruited in Hong Kong and Macau. Genomic DNA was extracted and genotyped by MassARRAY. In the discovery stage, 51 SNPs were investigated at the SNP, gene and pathway level among 103 EGFR mutant and 78 EGFR wild-type lung adenocarcinoma cases compared with matched controls. In the validation stage, SNPs that were identified with significant lung cancer risk were replicated in a separate cohort of 84 lung adenocarcinoma cases and compared with 103 Chinese Han, Beijing and 105 Chinese Han, Southern public controls from the 1000 genome database.

RESULTS AND CONCLUSION

The genetic association of IL-6 rs2069840 with EGFR mutant lung adenocarcinoma was ascertained. In the discovery stage, haplotype GGG in three SNPs (rs2069840, rs2069852, rs2066992) of IL-6, synergetic effects of IL-6 rs2069840 and environmental tobacco smoke in the workplace were found to be related to EGFR mutant lung adenocarcinoma. ERCC2 rs238406 showed a marginally significant association with EGFR mutant lung adenocarcinoma in the validation stage (P=0.096). ERCC2 rs50871 and ATM rs611646 showed significant association with EGFR wild-type lung adenocarcinoma in the discovery stage. In conclusion, IL-6 rs2069840 conferred susceptibility to EGFR mutant lung adenocarcinoma in a Hong Kong and Macau never-smoking Chinese population.

A NOVEL AND EFFICIENT ALGORITHM FOR DE NOVO DISCOVERY OF MUTATED DRIVER PATHWAYS IN CANCER

Next-generation sequencing studies on cancer somatic mutations have discovered that driver mutations tend to appear in most tumor samples, but they barely overlap in any single tumor sample, presumably because a single driver mutation can perturb the whole pathway. Based on the corresponding new concepts of coverage and mutual exclusivity, new methods can be designed for de novo discovery of mutated driver pathways in cancer. Since the computational problem is a combinatorial optimization with an objective function involving a discontinuous indicator function in high dimension, many existing optimization algorithms, such as a brute force enumeration, gradient descent and Newton's methods, are practically infeasible or directly inapplicable. We develop a new algorithm based on a novel formulation of the problem as non-convex programming and non-convex regularization. The method is computationally more efficient, effective and scalable than existing Monte Carlo searching and several other algorithms, which have been applied to The Cancer Genome Atlas (TCGA) project. We also extend the new method for integrative analysis of both mutation and gene expression data. We demonstrate the promising performance of the new methods with applications to three cancer datasets to discover de novo mutated driver pathways.

Germline Mutations in DNA Repair Genes in Lung Adenocarcinoma

INTRODUCTION

Although lung cancer is generally thought to be environmentally provoked, anecdotal familial clustering has been reported, suggesting that there may be genetic susceptibility factors. We systematically tested whether germline mutations in eight candidate genes may be risk factors for lung adenocarcinoma.

METHODS

We studied lung adenocarcinoma cases for which germline sequence data had been generated as part of The Cancer Genome Atlas project but had not been previously analyzed. We selected eight genes, ATM serine/threonine kinase gene (ATM), BRCA2, DNA repair associated gene (BRCA2), checkpoint kinase 2 gene (CHEK2), EGFR, parkin RBR E3 ubiquitin protein ligase gene (PARK2), telomerase reverse transcriptase gene (TERT), tumor protein p53 gene (TP53), and Yes associated protein 1 gene (YAP1), on the basis of prior anecdotal association with lung cancer or genome-wide association studies.

RESULTS

Among 555 lung adenocarcinoma cases, we detected 14 pathogenic mutations in five genes; they occurred at a frequency of 2.5% and represented an OR of 66 (95% confidence interval: 33-125, p < 0.0001 [chi-square test]). The mutations fell most commonly in ATM (50%), followed by TP53, BRCA2, EGFR, and PARK2. Most (86%) of these variants had been reported in other familial cancer syndromes. Another 12 cases (2%) carried ultrarare variants that were predicted to be deleterious by three protein prediction programs; these most frequently involved ATM and BRCA2.

CONCLUSIONS

A subset of patients with lung adenocarcinoma, at least 2.5% to 4.5%, carry germline variants that have been linked to cancer risk in Mendelian syndromes. The genes fall most frequently in DNA repair pathways. Our data indicate that patients with lung adenocarcinoma, similar to other solid tumors, include a subset of patients with inherited susceptibility.

The role of the ataxia telangiectasia mutated gene in lung cancer: recent advances in research

Lung cancer is the leading cause of death due to cancer worldwide. It is estimated that approximately 1.2 million new cases of lung cancer are diagnosed each year. Early detection and treatment are crucial for improvements in both prognosis and quality of life of lung cancer patients. The ataxia telangiectasia mutated (ATM) gene is a cancer-susceptibility gene that encodes a key apical kinase in the DNA damage response pathway. It has recently been shown to play an important role in the development of lung cancer. The main functions of the ATM gene and protein includes participation in cell cycle regulation, and identification and repair of DNA damage. ATM gene mutation can lead to multiple system dysfunctions as well as a concomitant increase in tumor tendency. In recent years, many studies have indicated that single nucleotide polymorphism of the ATM gene is associated with increased incidence of lung cancer. At the same time, the ATM gene and its encoding product ATM protein predicts the response to radiotherapy, chemotherapy, and prognosis of lung cancer, thus suggesting that the ATM gene may be a new potential target for the diagnosis and treatment of lung cancer.

Ataxia Telangiectasia-Mutated (ATM)Polymorphisms and Risk of Lung Cancer in a Chinese Population

BACKGROUND

The ataxia telangiectasia-mutated (ATM) gene has a key role in DNA repair including activation and stabilization of p53, which implicates the importance of ATM polymorphisms in the development of cancer. This study aims to investigate the association of two ATM single-nucleotide polymorphisms (SNPs) with lung cancer, as well as their potential interaction with p53 gene and other known risk factors of lung cancer.

METHODS

A population-based case-control study was conducted in Taiyuan city, China with 399 cases and 466 controls matched on the distribution of age and sex of cases. The two ATM gene SNPs, ATMrs227060 and ATMrs228589 as well as p53 gene SNP, p53rs1042522 were genotyped using Sequenom platform. Unconditional logistic regression models were used to estimate crude and adjusted odds ratios (aOR) and 95% confidence intervals (CIs). Adjusted models controlled for age, sex, and smoking status.

RESULTS

The study showed that TT genotype of ATMrs227060 (aOR = 1.58, 95% CI: 1.06-2.35) and AA genotype of ATMrs228589 were significantly associated with lung cancer (aOR = 1.50, 95% CI: 1.08-2.08) in a recessive model. Additionally, carrying variant genotypes of ATMrs227060 (TT), ATMrs228589 (AA), and p53rs1042522 (CC) concomitantly was associated with much higher risk (aOR = 3.68, 95% CI: 1.43-9.45) of lung cancer than carrying variant genotypes of any one of the above three SNPs. We also found multiplicative and additive interaction between tea drinking and ATMrs227060 in association with lung cancer.

CONCLUSION

This study indicates that ATM gene variants might be associated with development of lung cancer in Chinese population. These results need to be validated in larger and different population samples.

Next-generation sequencing of urine specimens: A novel platform for genomic analysis in patients with non-muscle-invasive urothelial carcinoma treated with bacille Calmette-Guérin

BACKGROUND

Biopsies from patients with high-risk (HR) non-muscle-invasive urothelial carcinoma (NMIUC), especially flat urothelial carcinoma in situ, frequently contain scant diagnostic material or denuded mucosa only, and this precludes further extensive genomic analysis. This study evaluated the use of next-generation sequencing (NGS) analysis of urine cytology material from patients with HR NMIUC in an attempt to identify genetic alterations that might correlate with clinical features and responses to bacille Calmette-Guérin (BCG) treatment.

METHODS

Forty-one cytology slides from patients with HR NMIUC treated with intravesical BCG were selected for this study. Histological confirmation was available for all cases. The specimens were subjected to NGS analysis with a customized targeted exome capture assay composed of 341 genes.

RESULTS

In this cohort, genomic alterations were successfully identified in all cytology samples. Mutations were detected down to a 2% allele frequency and chromosomal rearrangements including copy number alterations and gene fusions were identified. The most frequently altered genes included telomerase reverse transcriptase (TERT), tumor protein 53 (TP53), Erb-B2 receptor tyrosine kinase 2 (ERBB2), and chromatin remodeling genes such as lysine demethylase 6A (KDM6A) and AT-rich interaction domain 1A (ARID1A). For patients with matched tumor tissue, cytology specimens revealed all mutations detected in tissue as well as additional mutations, and this suggested that urine might more effectively capture the full genetic heterogeneity of disease than an individual cystectomy. Alterations in multiple genes correlated with clinical and histopathological features, including responses to BCG treatment, flat architecture versus papillary architecture, and smoking history.

CONCLUSIONS

Urine specimens can replace tissue as a substrate for NGS analysis of HR NMIUC. Several genomic alterations identified in urine specimens might be associated with histological features and clinical characteristics. Cancer Cytopathol 2017;125:416-26. © 2017 American Cancer Society.

Effect of ATM-111 (G>A) Polymorphism on Cancer Risk: A Meta-Analysis

OBJECTIVE

To assess the relationship between the ataxia telangiectasia mutated (ATM) gene-111 (G>A) polymorphism and cancer risk.

METHODS

The PubMed, EMBASE, Web of Science, and China National Knowledge Infrastructure databases were searched comprehensively. A total of 16 case-control studies with 12,273 cases and 13,046 controls were included in this meta-analysis; 12 of them were from the Chinese population. Five studies assessed smoking effects, including 3038 smokers and 1003 nonsmokers. Odds ratio (OR) was determined by using a genetic model-free approach. Heterogeneity was quantified by I(2) statistics. Publication bias was also evaluated.

RESULTS

The recessive model (AA vs. AG + GG) was suggested as the most appropriate genetic model. After elimination of heterogeneity, it was found that the ATM-111 (G>A) AA genotype is significantly associated with increased susceptibility to overall cancer risk in a fixed effects model (OR = 1.09; 95% CI = 1.03-1.15; p < 0.01; I(2) < 0.01). In the subgroup analysis, the result of pooled analyses among the Chinese population revealed similar associations (OR = 1.12; 95% CI = 1.04-1.22; p < 0.01; I(2) < 0.01). As for specific cancer analysis, an increase was correlated with lung cancer risk (OR = 1.12; 95% CI = 1.01-1.24; p = 0.03) and breast cancer risk (OR = 1.08; 95% CI = 1.00-1.16; p = 0.05). In addition, a stronger association was found among nonsmokers (OR = 1.31; 95% CI = 1.13-1.52; p < 0.01).

CONCLUSION

This meta-analysis suggests that AA genotype of the ATM-111 gene (G>A) may be a risk factor for breast cancer and lung cancer, especially among nonsmokers, within the Chinese population.

Lung Cancer in Never Smokers

Lung cancer is predominantly associated with cigarette smoking; however, a substantial minority of patients with the disease have never smoked. In the US it is estimated there are 17,000-26,000 annual deaths from lung cancer in never smokers, which as a separate entity would be the seventh leading cause of cancer mortality. Controversy surrounds the question of whether or not the incidence of lung cancer in never-smokers is increasing, with more data to support this observation in Asia. There are several factors associated with an increased risk of developing lung cancer in never smokers including second hand smoke, indoor air pollution, occupational exposures, and genetic susceptibility among others. Adenocarcinoma is the most common histology of lung cancer in never smokers and in comparison to lung cancer in smokers appears less complex with a higher likelihood to have targetable driver mutations.

Environmental tobacco smoke exposure and lung cancer: A systematic review

AIM: To review evidence relating passive smoking to lung cancer risk in never smokers, considering various major sources of bias.

METHODS: Epidemiological prospective or case-control studies were identified which provide estimates of relative risk (RR) and 95%CI for never smokers for one or more of seven different indices of exposure to environmental tobacco smoke (ETS): The spouse; household; workplace; childhood; travel; social and other; and total. A wide range of study details were entered into a database, and the RRs for each study, including descriptions of the comparisons made, were entered into a linked database. RRs were derived where necessary. Results were entered, where available, for all lung cancer, and for squamous cell cancer and adenocarcinoma. “Most adjusted” results were entered based on results available, adjusted for the greatest number of potential confounding variables. “Least adjusted” results were also entered, with a preference for results adjusted at least for age for prospective studies. A pre-planned series of fixed-effects and random-effects meta-analyses were conducted. Overall analyses and analyses by continent were run for each exposure index, with results for spousal smoking given by sex, and results for childhood exposure given by source of ETS exposure. For spousal exposure, more extensive analyses provide results by various aspects of study design and definition of the RR. For smoking by the husband (or nearest equivalent), additional analyses were carried out both for overall risk, and for risk per 10 cigarettes per day smoked by the husband. These adjusted for uncontrolled confounding by four factors (fruit, vegetable and dietary fat consumption, and education), and corrected for misclassification of smoking status of the wife. For the confounding adjustment, estimates for never smoking women were derived from publications on the relationship of the four factors to both lung cancer risk and at home ETS exposure, and on the correlations between the factors. The bias due to misclassification was calculated on the basis that the proportion of ever smokers denying smoking is 10% in Asian studies and 2.5% elsewhere, and that those who deny smoking have the same risk as those who admit it. This approach, justified in previous work, balances higher true denial rates and lower risk in deniers compared to non-deniers.

RESULTS: One hundred and two studies were identified for inclusion, published in 1981 onwards, 45 in Asia, 31 in North America, 21 in Europe, and five elsewhere. Eighty-five were of case-control design and 17 were prospective. Significant (P < 0.05) associations were noted, with random-effects of (RR = 1.22, 95%CI: 1.14-1.31, n = 93) for smoking by the husband (RR = 1.14, 95%CI: 1.01-1.29, n = 45) for smoking by the wife (RR = 1.22, 95%CI: 1.15-1.30, n = 47) for workplace exposure (RR = 1.15, 95%CI: 1.02-1.29, n = 41) for childhood exposure, and (RR = 1.31, 95%CI: 1.19-1.45, n = 48) for total exposure. No significant association was seen for ETS exposure in travel (RR = 1.34, 95%CI: 0.94-1.93, n = 8) or in social situations (RR = 1.01, 95%CI: 0.82-1.24, n = 15). A significant negative association (RR = 0.78, 95%CI: 0.64-0.94, n = 8) was seen for ETS exposure in childhood, specifically from the parents. Significant associations were also seen for spousal smoking for both squamous cell carcinoma (RR = 1.44, 95%CI: 1.15-1.80, n = 24) and adenocarcinoma (RR = 1.33, 95%CI: 1.17-1.51, n = 30). Results generally showed marked heterogeneity between studies. For smoking by either the husband or wife, where 119 RR estimates gave an overall estimate of (RR = 1.21, 95%CI: 1.14-1.29), the heterogeneity was highly significant (P < 0.001), with evidence that the largest RRs were seen in studies published in 1981-89, in small studies (1-49 cases), and for estimates unadjusted by age. For smoking by the husband, the additional analyses showed that adjustment for the four factors reduced the overall (RR = 1.22, 95%CI: 1.14-1.31) based on 93 estimates to (RR = 1.14, 95%CI: 1.06-1.22), implying bias due to uncontrolled confounding of 7%. Further correction for misclassification reduced the estimate to a marginally non-significant (RR = 1.08, 95%CI: 0.999-1.16). In the fully adjusted and corrected analyses, there was evidence of an increase in Asia (RR = 1.18, 95%CI: 1.07-1.30, n = 44), but not in other regions (RR = 0.96, 95%CI: 0.86-1.07, n = 49). Studies published in the 1980’s, studies providing dose-response data, and studies only providing results unadjusted for age showed elevated RRs, but later published studies, studies not providing dose-response data, and studies adjusting for age did not. The pattern of results for RRs per 10 cigs/d was similar, with no significant association in the adjusted and corrected results (RR = 1.03, 95%CI: 0.994-1.07).

CONCLUSION: Most, if not all, of the ETS/lung cancer association can be explained by confounding adjustment and misclassification correction. Any causal relationship is not convincingly demonstrated.

ATM rs189037 (G > A) polymorphism and risk of lung cancer and head and neck cancer: A meta-analysis

A number of different epidemiological studies have measured the association between the risk of different cancers and polymorphism at promoter region of 5′ untranslated region (5′-UTR) of the Ataxia-telangiectasia mutated (ATM) gene. However the results were contentious rather than conclusive. The current study was aimed at evaluating the association between the SNP (rs189037 G>A) and the risk of head and neck cancer and lung cancer by conducting a meta-analysis. A total of 9 case–control studies were considered for this quantitative analysis. Stats Direct Statistical software (version 2.7.2) was used to evaluate the crude odds ratio (OR) with their 95% confidence interval (CI). The dominant model (GG vs. GA + AA) showed no heterogeneity and the fixed effects pooled OR was found to be significant (OR = 1.14, 95% CI = 1.05–1.25) at p = 0.003. The pooled OR for fixed effects of heterozygote and homozygote mutant allele (GA vs. AA) model was significant (OR = 1.17, 95% CI = 1.04–1.30, p = 0.006) and no heterogeneity was observed for this model. The current meta-analysis manifested that ATM rs189037 G>A genetic polymorphism may contribute increased risk of head and neck and lung cancer. Moreover, the AA mutant allele was found to be related significantly with the prognosis of lung cancer and head and neck cancer.

ATM gene single nucleotide polymorphisms predict regimen-related gastrointestinal toxicity in patients allografted after reduced conditioning

Polymorphisms of genes involved in innate and adaptive immunity have become an object of major interest in regard to hematopoietic stem cell transplantation (HSCT) complications. Regimen-related gastrointestinal toxicity (RR-GIT) is the dominant complication during the pre-engraftment period and has been linked to increased risk of graft-versus-host disease (GVHD) development. According to our hypothesis, functional variants of genes participating in DNA damage response (DDR) may have an impact on the extent of tissue damage caused by the conditioning regimen. In our single-center study, we analyzed 62 patients who underwent HSCT from HLA-identical donors after reduced conditioning. The patients were genotyped for 5 single nucleotide polymorphisms (SNPs, rs4585 T/G, rs189037 A/G, rs227092 T/G, rs228590 C/T, and rs664677 T/C) of the ATM gene-the essential member of the DDR pathways, using allele-specific matrix-assisted laser desorption/ionization, time-of-flight (MALDI-TOF) mass spectrometry assay. Because of almost absolute linkage disequilibrium observed among all 5 SNPs, association of 2 major ATM haplotypes (ATM1/ATM2) with RR-GIT and acute GVHD (aGVHD) was analyzed. Importantly, the univariate and multivariate analysis showed that patients homozygous for ATM2 haplotype (rs4585*T, rs189037*A, rs227092*T, rs228590*C, and rs664677*T) are more likely to suffer from high-grade RR-GIT than ATM1 homozygous patients. The association with aGVHD was not significant. To our knowledge, this is the first report showing the ATM gene variability in relation to RR-GIT in the allogeneic HSCT setting.

Single nucleotide polymorphisms of ataxia telangiectasia mutated and the risk of papillary thyroid carcinoma

Genetic factors associated with susceptibility to papillary thyroid carcinoma (PTC) are not well known. We evaluated the association between single nucleotide polymorphisms (SNPs) of ataxia telangiectasia mutated (ATM) and the risk of PTC. A total of 437 histologically confirmed PTC cases and 184 cancer-free controls without thyroid nodules were recruited. Genotypes with respect to five ATM SNPs (rs189037, rs664677, rs373759, rs664143, and rs4585) were determined by the TaqMan assay, and odds ratios and 95% confidence intervals were obtained by logistic regression analysis. Linkage disequilibria and haplotypes were examined from the genotype data. When evaluated separately the genotype distributions of the five ATM SNPs were similar in the PTC cases and controls. Three ATM SNPs (rs373759, rs664143, and rs4585) were found to be in strong linkage disequilibrium (D' = 1.00, P < 0.001). When the three haplotypes (C-A-G), (T-G-T), and (C-G-T) of these three ATM SNP sites were analyzed, ATM haplotype (C-G-T) +/- was associated with a lower risk of PTC than ATM haplotype (C-G-T) -/- (P = 0.03) after adjusting for age and gender. Our results suggest that genetic polymorphisms of ATM may play an important role in the development of thyroid cancer in the Korean population.

Effect of single nucleotide polymorphism Rs189037 in ATM gene on risk of lung cancer in Chinese: a case-control study

Background

Accumulated evidence has indicated that ataxia-telangiectasia mutated (ATM) gene polymorphisms are closely related to lung cancer. We aimed to explore the prognostic value of rs189037 (G>A), one of ATM single nucleotide polymorphisms (SNPs), and detect whether it involves in the risk of lung cancer in Chinese Han people.

Methods

In this hospital-based matched case-control study, 852 lung cancer patients and 852 healthy controls have been put into comparison to analyze the association between rs189037 and lung cancer risk in Chinese. The single nucleotide polymorphisms were determined by TaqMan real-time PCR and we used SPSS software to perform the statistical analyses.

Results

Individuals carrying variant AA genotype of rs189037 had higher lung cancer risk (adjusted OR: 1.56) than those carrying GG genotype. After analyzing data respectively from different groups divided by genders and smoking status, we observed that the risk effect of AA genotype on the lung cancer was significant in females, non-smokers and female non-smokers, as well as the risk effect of GA genotype in male smokers. Compared with non-smokers carrying GG genotype, smokers carrying at least one A allele had higher risk of developing lung cancer than those with GG genotype (adjusted OR: 3.52 vs. adjusted OR: 2.53).

Conclusions

This study suggested that rs189037 (G>A) polymorphism is associated with lung cancer risk in Chinese Han population. AA genotype and A allele may be dangerous lung cancer signals in Chinese and make contribution to diagnostic and treatment value.

Single nucleotide polymorphism in ATM gene, cooking oil fumes and lung adenocarcinoma susceptibility in Chinese female non-smokers: a case-control study

BACKGROUND

The ataxia-telangiectasia mutated (ATM) gene plays an important role in the DNA double-strand breaks repair pathway. Single nucleotide polymorphisms (SNPs) of DNA repair genes are suspected to influence the risk of lung cancer. This study aimed to investigate the association between the ATM -111G>A (rs189037) polymorphism, environmental risk factors and the risk of lung adenocarcinoma in Chinese female non-smokers.

METHODS

A hospital-based case-control study of 487 lung cancer patients and 516 matched cancer-free controls was conducted. Information concerning demographic and environmental risk factors was obtained for each case and control by a trained interviewer. After informed consent was obtained, 10 ml venous blood was collected from each subject for biomarker testing. Single nucleotide polymorphism was determined by using TaqMan method.

RESULTS

This study showed that the individuals with ATM rs189037 AA genotype were at an increased risk for lung adenocarcinoma compared with those carrying the GA or GG genotype (adjusted odds ratios (OR) 1.44, 95% confidence interval (CI) 1.02-2.02, P = 0.039). The stratified analysis suggested that increased risk associated with ATM rs189037 AA genotype in individuals who never or seldom were exposed to cooking oil fumes (adjusted OR 1.89, 95%CI 1.03-3.49, P = 0.040).

CONCLUSIONS

ATM rs189037 might be associated with the risk of lung adenocarcinoma in Chinese non-smoking females. Furthermore, ATM rs189037 AA genotype might be a risk factor of lung adenocarcinoma among female non-smokers without cooking oil fume exposure.

Genetic factors in individual radiation sensitivity

Cancer risk and radiation sensitivity are often associated with alterations in DNA repair, cell cycle, or apoptotic pathways. Interindividual variability in mutagen or radiation sensitivity and in cancer susceptibility may also be traced back to polymorphisms of genes affecting e.g. DNA repair capacity. We studied possible associations between 70 polymorphisms of 12 DNA repair genes with basal and initial DNA damage and with repair thereof. We investigated DNA damage induced by ionizing radiation in lymphocytes isolated from 177 young lung cancer patients and 169 cancer-free controls. We also sought replication of our findings in an independent sample of 175 families (in total 798 individuals). DNA damage was assessed by the Olive tail moment (OTM) of the comet assay. DNA repair capacity (DRC) was determined for 10, 30 and, 60min of repair. Genes involved in the single-strand-repair pathway (SSR; like XRCC1 and MSH2) as well as genes involved in the double-strand-repair pathway (DSR; like RAD50, XRCC4, MRE11 and ATM) were found to be associated with DNA damage. The most significant association was observed for marker rs3213334 (p=0.005) of XRCC1 with basal DNA damage (B), in both cases and controls. A clear additive effect on the logarithm of OTM was identified for the marker rs1001581 of the same LD-block (p=0.039): BCC=-1.06 (95%-CI: -1.16 to -0.96), BCT=-1.02 (95%-CI: -1.11 to -0.93) and BTT=-0.85 (95%-CI: -1.01 to -0.68). In both cases and controls, we observed significantly higher DNA basal damage (p=0.007) for carriers of the genotype AA of marker rs2237060 of RAD50 (involved in DSR). However, this could not be replicated in the sample of families (p=0.781). An alteration to DRC after 30min of repair with respect to cases was observed as borderline significant for marker rs611646 of ATM (involved in DSR; p=0.055), but was the most significant finding in the sample of families (p=0.009). Our data indicate that gene variation impacts measurably on DNA damage and repair, suggesting at least a partial contribution to radiation sensitivity and lung cancer susceptibility.

Risk factors for primary lung cancer among never smokers by gender in a matched case-control study

OBJECTIVE

Lung cancers that occur in never smokers differ from those that occur in smokers. We performed an analysis of potential epidemiological risk factors for lung cancer among never smokers.

METHODS

In this hospital-based matched case-control study, all 1,540 matched case-control pairs were Han Chinese in Taiwan. The data on demographic characteristics, smoking habit, exposure to environmental tobacco smoke, medical history of lung diseases, family history of lung cancer, and female characteristics were collected from a structured questionnaire. A multiple conditional logistic regression was used to estimate odds ratios and 95 % confidence intervals after adjusting for possible confounders.

RESULTS

Overall, several epidemiological factors of lung cancer in never smokers were different between males and females. For the female population, subjects who were exposed to environmental tobacco smoke (OR = 1.39, 95 % CI = 1.17-1.67) with a history of pulmonary tuberculosis and with family history of lung cancer in first-degree relatives (OR = 2.44, 95 % CI = 1.79-3.32) had higher risk of lung cancer, while subjects with a history of hormone replacement therapy and using fume extractors for those who cooked were protective. For the male population, only subjects with family history of lung cancer in first-degree relatives (OR = 2.77, 95 % CI = 1.53-5.01) were significantly associated with risk of lung cancer.

CONCLUSION

This study provides insights about the epidemiological factors of lung cancer in never smokers, adding to existing evidence that family history of lung cancer and environmental tobacco smoke may moderate lung cancer risk.

A phase I combination study of olaparib with cisplatin and gemcitabine in adults with solid tumors

PURPOSE

To determine the safety and tolerability of olaparib with cisplatin and gemcitabine, establish the maximum tolerated dose (MTD), and evaluate the pharmacodynamic and pharmacokinetic profile of the combination.

EXPERIMENTAL DESIGN

We conducted a phase I study of olaparib with cisplatin and gemcitabine in patients with advanced solid tumors. Treatment at dose level 1 (DL1) consisted of olaparib 100 mg orally every 12 hours on days 1 to 4, gemcitabine 500 mg/m(2) on days 3 and 10, and cisplatin 60 mg/m(2) on day 3. PAR levels were measured in peripheral blood mononuclear cells (PBMC).

RESULTS

Dose-limiting toxicities (DLT) in two of three patients at DL1 included thrombocytopenia and febrile neutropenia. The protocol was amended to enroll patients treated with ≤ 2 prior severely myelosuppressive chemotherapy regimens and treated with olaparib 100 mg once daily on days 1 to 4 (DL-1). No DLTs were seen in six patients at DL-1. Because of persistent thrombocytopenia and neutropenia following a return to DL1, patients received 100 mg olaparib every 12 hours on day 1 only. No hematologic DLTs were observed; nonhematologic DLTs included gastrointestinal bleed, syncope, and hypoxia. Of 21 patients evaluable for response, two had partial response. Olaparib inhibited PARP in PBMCs and tumor tissue, although PAR levels were less effectively inhibited when olaparib was used for a short duration.

CONCLUSIONS

Olaparib in combination with cisplatin and gemcitabine is associated with myelosuppression even at relatively low doses. Modified schedules of olaparib in chemotherapy naive patients will have to be explored with standard doses of chemotherapy.

Against Lung Cancer Cells: To Be, or Not to Be, That Is the Problem

Tobacco smoke and radioactive radon gas impose a high risk for lung cancer. The radon-derived ionizing radiation and some components of cigarette smoke induce oxidative stress by generating reactive oxygen species (ROS). Respiratory lung cells are subject to the ROS that causes DNA breaks, which subsequently bring about DNA mutagenesis and are intimately linked with carcinogenesis. The damaged cells by oxidative stress are often destroyed through the active apoptotic pathway. However, the ROS also perform critical signaling functions in stress responses, cell survival, and cell proliferation. Some molecules enhance radiation-induced tumor cell killing via the reduction in DNA repair levels. Hence the DNA repair levels may be a novel therapeutic modality in overcoming drug resistance in lung cancer. Either survival or apoptosis, which is determined by the balance between DNA damage and DNA repair levels, may lender the major problems in cancer therapy. The purpose of this paper is to take a closer look at risk factor and at therapy modulation factor in lung cancer relevant to the ROS.

The association between ATM IVS 22-77 T>C and cancer risk: a meta-analysis

Background and Objectives

It has become increasingly clear that ATM (ataxia-telangiectasia-mutated) safeguards genome stability, which is a cornerstone of cellular homeostasis, and ATM IVS 22-77 T>C affects the normal activity of ATM proteins. However, the association between the ATM IVS 22-77 T>C genetic variant and cancer risk is controversial. Therefore, we conducted a systematic meta-analysis to estimate the overall cancer risk associated with the polymorphism and to quantify any potential between-study heterogeneity.

Methods

A total of nine studies including 4,470 cases and 4,862 controls were analyzed for ATM IVS 22-77 T>C association with cancer risk in this meta-analysis. Heterogeneity among articles and their publication bias were also tested.

Results

Our results showed that no association reached the level of statistical significance in the overall risk. Interestingly, in the stratified analyses, we observed an inverse relationship in lung and breast cancer.

Conclusion

Further functional research on the ATM mechanism should be performed to explain the inconsistent results in different cancer types.

Association between ATM polymorphisms and cancer risk: a meta-analysis

To date, epidemiological studies have assessed the association between Ataxia-telangiectasia mutated (ATM) gene polymorphisms and cancer risk, including lung cancer, breast cancer, glioma and pancreatic cancer. However, the results of these studies remain controversial. We aimed to examine the associations between two SNPs (rs664143 and rs664677) and cancer risk by conducting a meta-analysis of case-control studies. A total of 12 publications were included in this meta-analysis, 8 for rs664143 and 7 for rs664677. Overall, rs664143 heterozygote carriers turned out to be associated with cancer risk (OR = 1.18, 95% CI 1.02-1.36). In the subgroup analysis by cancer type, we observed that the ATM rs664143 polymorphism was significantly associated with lung cancer risk (GA vs. GG: OR = 1.48, 95% CI 1.18-1.85, AA vs. GG: OR = 1.51, 95% CI 1.18-1.93) and rs664677 polymorphism was associated with decreased lung cancr risk and increased breast cancer risk (for lung cancer: TC vs. TT: OR = 0.76, 95% CI 0.62-0.92, CC vs. TT: OR = 0.80, 95% CI 0.64-0.99 and for breast cancer: TC vs. TT: OR = 1.42, 95% CI 1.17-1.73, CC vs. TT: OR = 1.51, 95% CI 1.21-1.87). In the subgroup analysis by region, we also observed that individuals with ATM rs664143 GA or AA genotype had an obvious increased cancer risk among Asian people (GA vs. GG: OR = 1.40, 95% CI 1.20-1.63, AA vs. GG: OR = 1.37, 95% CI 1.16-1.62). In conclusion, ATM rs664143 polymorphism was associated with cancer susceptibility. ATM rs664143 polymorphism was significantly associated with lung cancer risk. ATM rs664677 polymorphism was associated with decreased lung cancer risk as well as increased breast cancer risk.

Polymorphisms of MLH1 and MSH2 genes and the risk of lung cancer among never smokers

Mismatch repair (MMR) plays an important role in repairing nucleotide mismatches during DNA replication. Defects in MMR genes are associated with some sporadic tumors. MLH1 and MSH2 are two of the MMR genes. We conducted a case-control study to investigate the associations between the risk of lung cancer and genetic polymorphisms in the MLH1 and MSH2 genes. The SNP genotypes were determined in 730 lung cancer patients and 730 healthy controls that were frequency matched for the age, gender, and smoking status. Among the SNP polymorphisms, -93A>G (rs1800734), which is located in the promoter region of MLH1, was significantly associated with the risk of lung cancer. The GG genotype for MLH1 -93A>G was associated with a significantly increased risk of lung cancer compared with the AA genotype among the never-smoking group (adjusted OR=1.64, 95% CI=1.10-2.44; P=0.013). Consistently, the haplotype of MLH1 with one -93G risk allele was associated with the risk of lung cancer compared with the AA haplotype among the never-smoking group. Furthermore, the risk of MLH1 -93A>G polymorphism in the never-smoking group related to lung adenocarcinoma was modulated by environmental tobacco smoke (ETS) exposure status, with a significant gene-ETS interaction (P=0.042). No evidence was found of the association between MSH2 and the lung cancer risk. In conclusion, our data suggest that the MLH1 -93A>G polymorphism may contribute to the etiology of lung cancer, particularly in never smokers. This study also suggests that MLH1 -93A>G polymorphisms and ETS exposure have a role in the tumorigenesis of lung adenocarcinoma among never smokers.