Search

We assessed the association between a genome-wide polygenic risk score (PRS) developed for lung adenocarcinoma (LUAD) risk and mutation on the epidermal growth factor receptor (EGFR) gene in 998 East Asian never-smoking female LUAD cases (518 EGFR-positive; 480 EGFR-negative) and 4,544 never-smoking controls using case-case and multinomial regression analyses. We found that the PRS was more strongly associated with EGFR-positive LUAD compared to EGFR-negative LUAD, where the association between the fourth quartile of the PRS and EGFR-positive LUAD (OR=8.63, 95% CI:5.67, 13.14) was significantly higher than the association between the fourth quartile of the PRS with EGFR-negative LUAD (OR=3.50, 95% CI: 2.44, 5.00) (p-heterogeneity=3.66x10 -3 ). Our findings suggest that germline genetic susceptibility may be differentially associated with LUAD in never-smoking female East Asian patients depending on the cancer's mutation status, which may have important public health and clinical implications., (Copyright © 2024. Published by Elsevier Inc.)

Polygenic risk scores (PRSs) are promising for risk stratification but have mainly been developed in European populations. This study developed single- and multi-ancestry PRSs for lung adenocarcinoma (LUAD) in East Asian (EAS) never-smokers using genome-wide association study summary statistics from EAS (8,002 cases; 20,782 controls) and European (2,058 cases; 5,575 controls) populations. A multi-ancestry PRS, developed using CT-SLEB, was strongly associated with LUAD risk (odds ratio=1.71, 95% confidence interval (CI):1.61,1.82), with an area under the receiver operating curve value of 0.640 (95% CI:0.629,0.653). Individuals in the highest 20% of the PRS had nearly four times the risk compared to the lowest 20%. Individuals in the 95 th percentile of the PRS had an estimated 6.69% lifetime absolute risk. Notably, this group reached the average population 10-year LUAD risk at age 50 (0.42%) by age 41. Our study underscores the potential of multi-ancestry PRS approaches to enhance LUAD risk stratification in EAS never-smokers.

Lung adenocarcinoma is the most common type of lung cancer. Known risk variants explain only a small fraction of lung adenocarcinoma heritability. Here, we conducted a two-stage genome-wide association study of lung adenocarcinoma of East Asian ancestry (21,658 cases and 150,676 controls; 54.5% never-smokers) and identified 12 novel susceptibility variants, bringing the total number to 28 at 25 independent loci. Transcriptome-wide association analyses together with colocalization studies using a Taiwanese lung expression quantitative trait loci dataset (n = 115) identified novel candidate genes, including FADS1 at 11q12 and ELF5 at 11p13. In a multi-ancestry meta-analysis of East Asian and European studies, four loci were identified at 2p11, 4q32, 16q23, and 18q12. At the same time, most of our findings in East Asian populations showed no evidence of association in European populations. In our studies drawn from East Asian populations, a polygenic risk score based on the 25 loci had a stronger association in never-smokers vs. individuals with a history of smoking (P interaction  = 0.0058). These findings provide new insights into the etiology of lung adenocarcinoma in individuals from East Asian populations, which could be important in developing translational applications., (© 2023. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

We investigated whether genetic susceptibility to tuberculosis (TB) influences lung adenocarcinoma development among never-smokers using TB genome-wide association study (GWAS) results within the Female Lung Cancer Consortium in Asia. Pathway analysis with the adaptive rank truncated product method was used to assess the association between a TB-related gene-set and lung adenocarcinoma using GWAS data from 5512 lung adenocarcinoma cases and 6277 controls. The gene-set consisted of 31 genes containing known/suggestive associations with genetic variants from previous TB-GWAS. Subsequently, we followed-up with Mendelian Randomization to evaluate the association between TB and lung adenocarcinoma using three genome-wide significant variants from previous TB-GWAS in East Asians. The TB-related gene-set was associated with lung adenocarcinoma (p = 0.016). Additionally, the Mendelian Randomization showed an association between TB and lung adenocarcinoma (OR = 1.31, 95% CI: 1.03, 1.66, p = 0.027). Our findings support TB as a causal risk factor for lung cancer development among never-smoking Asian women., (Copyright © 2019. Published by Elsevier Inc.)

To evaluate associations by EGFR mutation status for lung adenocarcinoma risk among never-smoking Asian women, we conducted a meta-analysis of 11 loci previously identified in genome-wide association studies (GWAS). Genotyping in an additional 10,780 never-smoking cases and 10,938 never-smoking controls from Asia confirmed associations with eight known single nucleotide polymorphisms (SNPs). Two new signals were observed at genome-wide significance (P < 5 × 10-8), namely, rs7216064 (17q24.3, BPTF), for overall lung adenocarcinoma risk, and rs3817963 (6p21.3, BTNL2) which is specific to cases with EGFR mutations. In further sub-analyses by EGFR status, rs9387478 (ROS1/DCBLD1) and rs2179920 (HLA-DPB1) showed stronger estimated associations in EGFR-positive compared to EGFR-negative cases. Comparison of the overall associations with published results in Western populations revealed that the majority of these findings were distinct, underscoring the importance of distinct contributing factors for smoking and non-smoking lung cancer. Our results extend the catalogue of regions associated with lung adenocarcinoma in non-smoking Asian women and highlight the importance of how the germline could inform risk for specific tumour mutation patterns, which could have important translational implications., (Published by Oxford University Press 2016. This work is written by US Government employees and is in the public domain in the US.)

Genome-wide association studies (GWAS) of lung cancer in Asian never-smoking women have previously identified six susceptibility loci associated with lung cancer risk. To further discover new susceptibility loci, we imputed data from four GWAS of Asian non-smoking female lung cancer (6877 cases and 6277 controls) using the 1000 Genomes Project (Phase 1 Release 3) data as the reference and genotyped additional samples (5878 cases and 7046 controls) for possible replication. In our meta-analysis, three new loci achieved genome-wide significance, marked by single nucleotide polymorphism (SNP) rs7741164 at 6p21.1 (per-allele odds ratio (OR) = 1.17; P = 5.8 × 10(-13)), rs72658409 at 9p21.3 (per-allele OR = 0.77; P = 1.41 × 10(-10)) and rs11610143 at 12q13.13 (per-allele OR = 0.89; P = 4.96 × 10(-9)). These findings identified new genetic susceptibility alleles for lung cancer in never-smoking women in Asia and merit follow-up to understand their biological underpinnings., (Published by Oxford University Press 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Background: This study was conducted to investigate whether a panel of eight genetic polymorphisms can predict the prognosis of patients with early stage non-small cell lung cancer (NSCLC) after surgical resection., Materials and Methods: We selected eight single nucleotide polymorphisms (SNPs) which have been associated with the prognosis of lung cancer patients after surgery in our previous studies. A total of 814 patients with early stage NSCLC who underwent curative surgical resection were enrolled. The association of the eight SNPs with overall survival (OS) and disease-free survival (DFS) was analyzed., Results: The eight SNPs (CD3EAP rs967591, TNFRSF10B rs1047266, AKT1 rs3803300, C3 rs2287845, HOMER2 rs1256428, GNB2L1 rs3756585, ADAMTSL3 rs11259927, and CD3D rs3181259) were significantly associated with OS and/or DFS. Combining those eight SNPs, we designed a prognostic index to predict the prognosis of patients. According to relative risk of death, a score value was assigned to each genotype of the SNPs. A worse prognosis corresponded to a higher score value, and the sum of score values of eight SNPs defined the prognostic index of a patient. When we categorized the patients into two groups based on the prognostic index, high risk group was significantly associated with worse OS and DFS compared to low risk group (aHR for OS = 2.21, 95% CI = 1.69-2.88, P = 8.0 x 10-9, and aHR for DFS = 1.58, 95% CI = 1.29-1.94, P = 1.0 x 10-5)., Conclusions: Prognostic index using eight genetic polymorphisms may be useful for the prognostication of patients with surgically resected NSCLC.

Background: Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites., Methods: Between 2007 and 2014, the US National Cancer Institute has generated data from genome-wide association studies (GWAS) for 49 492 cancer case patients and 34 131 control patients. We apply novel mixed model methodology (GCTA) to this GWAS data to estimate the heritability of individual cancers, as well as the proportion of heritability attributable to cigarette smoking in smoking-related cancers, and the genetic correlation between pairs of cancers., Results: GWAS heritability was statistically significant at nearly all sites, with the estimates of array-based heritability, hl (2), on the liability threshold (LT) scale ranging from 0.05 to 0.38. Estimating the combined heritability of multiple smoking characteristics, we calculate that at least 24% (95% confidence interval [CI] = 14% to 37%) and 7% (95% CI = 4% to 11%) of the heritability for lung and bladder cancer, respectively, can be attributed to genetic determinants of smoking. Most pairs of cancers studied did not show evidence of strong genetic correlation. We found only four pairs of cancers with marginally statistically significant correlations, specifically kidney and testes (ρ = 0.73, SE = 0.28), diffuse large B-cell lymphoma (DLBCL) and pediatric osteosarcoma (ρ = 0.53, SE = 0.21), DLBCL and chronic lymphocytic leukemia (CLL) (ρ = 0.51, SE =0.18), and bladder and lung (ρ = 0.35, SE = 0.14). Correlation analysis also indicates that the genetic architecture of lung cancer differs between a smoking population of European ancestry and a nonsmoking Asian population, allowing for the possibility that the genetic etiology for the same disease can vary by population and environmental exposures., Conclusion: Our results provide important insights into the genetic architecture of cancers and suggest new avenues for investigation., (Published by Oxford University Press 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

During cancer progression, some tumor cells show changes in their plasticity by morphological and phenotypical conversions, as an expression of mesenchymal markers and loss of epithelial markers, collectively referred to as epithelial-mesenchymal transition (EMT). EMT has been increasingly recognized as a critical phenomenon in lung cancer progression. The goal of this study was to identify microRNAs involved in lung cancer progression. A microarray and qRT-PCR were performed to investigate the miRNA expression profiles in mesenchymal-like lung cancer cells. The role of miR‑146a in lung cancer progression was measured by invasion and migration assays in vitro. Bioinformatics and luciferase report assays were used to identify the target of miR‑146a. The expression of miR‑146a was reduced in mesenchymal-like lung cancer cell lines. The overexpression of miR‑146a induced a marked reduction of the mesenchymal marker and increase the epithelial marker in lung cancer cell lines. Moreover, the overexpression of miR‑146a suppressed lung cancer cell migration and invasion. Co-treatment with miR‑146a and gefitinib treatment showed a significant reduction of invasion in the resistant lung cancer cells induced by EMT. The expression of miR‑146a was downregulated in advanced lung cancer tissues. Insulin receptor substrate 2 (IRS2), an adaptor protein that modulates normal growth, metabolism, survival, and differentiation, was identified as a target of miR‑146a. miR‑146a regulated the expression of IRS2 at the mRNA and protein levels. These data demonstrate for the first time that miR‑146a suppresses lung cancer progression by repressing IRS2 expression. This provides new insight into the post-transcriptional regulation of lung cancer progression by miRNAs, a potential approach for the treatment of lung cancer.

We searched for potential regulatory single nucleotide polymorphisms (SNPs) in excision repair cross-complementing group 1 (ERCC1) using RegulomeDB, a database integrating information from the Encyclopedia of DNA Elements (ENCODE) project, and investigated their association with survival after surgery in non-small cell lung cancer (NSCLC). Among 364 SNPs found within ERCC1 region using RegulomeDB, four top priority SNPs (rs2298881C>A, rs1049739A>G, rs10415949A>G and rs6509214G>T) were selected for this study. The four SNPs were investigated in 316 patients. A replication study was performed (n = 579). Of the four SNPs analyzed in the discovery set, rs2298881C>A and rs6509214G>T were significantly associated with survival outcomes. The association was consistently observed only for rs2298881C>A in the validation cohort. In combined analysis, rs2298881C>A was significantly associated with worse overall survival and disease-free survival (P = 0.0002 and 0.02, respectively). A decreased reporter gene expression for rs2298881 A allele was observed compared with C allele by luciferase assay (P = 0.02). ERCC1 rs2298881C>A, an intronic SNP, is the first genetic polymorphism with functional evidence of regulating its expression, and the SNP is associated with prognosis of NSCLC. Our result supports the role of RegulomeDB as a comprehensive source of prioritized candidate SNPs for genetic association studies.

Background/aims: A number of genome-wide and candidate gene association studies have identified polymorphisms associated with telomere length in Caucasian populations. This study was conducted to determine the impacts of 17 polymorphisms identified in Caucasians on telomere length in a Korean population., Methods: Ninety-four healthy individuals were enrolled in this study. Relative telomere length of chromosomes from peripheral blood samples was measured using quantitative polymerase chain reaction., Results: Two polymorphisms, rs10936599 of MYNN and rs412658 of ZNF676, were found to be associated w ith telomere length (under dominant model, p = 0.04; under recessive model, p = 0.001). Three polymorphisms, rs2853669, rs7705526, and rs2736108, at the TERT locus were also associated with telomere length (under recessive model, p = 0.01, p = 0.02, and p = 0.01, respectively). The genotypes of the five polymorphisms associated with short telomere length were considered bad genotypes; telomere length was significantly decreased with increasing number of bad genotypes (p= 1.7 × 10(-5))., Conclusions: We have identified polymorphisms associated with telomere length in a Korean population.

Recent evidence from several relatively small nested case-control studies in prospective cohorts shows an association between longer telomere length measured phenotypically in peripheral white blood cell (WBC) DNA and increased lung cancer risk. We sought to further explore this relationship by examining a panel of seven telomere-length associated genetic variants in a large study of 5,457 never-smoking female Asian lung cancer cases and 4,493 never-smoking female Asian controls using data from a previously reported genome-wide association study. Using a group of 1,536 individuals with phenotypically measured telomere length in WBCs in the prospective Shanghai Women's Health study, we demonstrated the utility of a genetic risk score (GRS) of seven telomere-length associated variants to predict telomere length in an Asian population. We then found that GRSs used as instrumental variables to predict longer telomere length were associated with increased lung cancer risk (OR = 1.51 (95% CI = 1.34-1.69) for upper vs. lower quartile of the weighted GRS, p value = 4.54 × 10(-14) ) even after removing rs2736100 (p value = 4.81 × 10(-3) ), a SNP in the TERT locus robustly associated with lung cancer risk in prior association studies. Stratified analyses suggested the effect of the telomere-associated GRS is strongest among younger individuals. We found no difference in GRS effect between adenocarcinoma and squamous cell subtypes. Our results indicate that a genetic background that favors longer telomere length may increase lung cancer risk, which is consistent with earlier prospective studies relating longer telomere length with increased lung cancer risk., (Published 2014. This article is a US Government work and, as such, is in the public domain of the United States of America.)

Background: This study was conducted to identify genetic polymorphisms associated with the prognosis of patients with early stage NSCLC., Materials and Methods: We genotyped 1,969 potentially functional single nucleotide polymorphisms (SNPs) of 1,151 genes involved in carcinogenesis in 166 NSCLC patients who underwent curative surgery, using the Affymetrix custom-made GeneChip. A replication study was performed in an independent cohort of 626 patients., Results: Fifty six SNPs which were associated with both overall survival (OS) and disease-free survival (DFS) with log-rank P values < 0.05 in discovery set were selected for validation. Among those, five SNPs (RACK1 rs1279736C>A and rs3756585T>G, C3 rs2287845T>C, PCAF rs17006625A>G, and PCM1 rs17691523C>G) were found to be significantly associated with survival in the same direction as the discovery set. In combined analysis, the rs1279736C>A and rs3756585T>G were most significantly associated with OS and DFS in multivariate analysis (P for OS = 4 × 10⁻⁵ and 7 × 10⁻⁵, respectively; and P for DFS = 0.003, both; under codominant model). In vitro promoter assay and electrophoretic mobility shift assay revealed that the rs3756585 T-to-G change increased promoter activity and transcription factor binding of RACK1., Conclusions: We identified five SNPs, especially RACK1 rs3756585T>G, as markers for prognosis of patients with surgically resected NSCLC.

The Encyclopedia of DNA elements (ENCODE) project revealed that nearby or distantly located non-coding DNA regulates the expression of coding genes. RegulomeDB (http://regulome.stanford.edu) is a new database that can be used to predict whether a variant affects transcription factor binding and gene expression. We investigated the association between lung cancer risk and potentially functional polymorphisms of XRCC1 that were selected using RegulomeDB in a Korean population. A total of 185 polymorphisms of XRCC1 were evaluated using RegulomeDB. Strong evidence suggested that 10 polymorphisms, from among the 185, affected XRCC1 expression with scores of 1a-1f that were based on the RegulomeDB scoring system. The rs2854510 polymorphism was rare in Asians (minor allele frequency < 0.05). Eight polymorphisms were in strong linkage disequilibrium (LD). The rs2854509 polymorphism, which was one of the 8 polymorphisms in LD, and rs7248167, which was not in the LD block, were genotyped in 610 lung cancer patients and 607 age- and sex-matched controls. Additionally, four polymorphisms of XRCC1 (rs25487, rs25489, rs1799782, and rs3213245), which were investigated with regard to their association with lung cancer risk in previous studies, were also genotyped. Two polymorphisms (rs2854509 and rs7248167) that were predicted to affect XRCC1 expression based on their RegulomeDB scores were not associated with lung cancer risk (P = 0.31 and 0.93, respectively). When stratified according to age, gender, smoking status, and tumor histology, the two polymorphisms of XRCC1 were not associated with lung cancer risk. Among the four polymorphisms that were previously studied, only rs25489 of XRCC1 was significantly associated with lung cancer risk (dominant model, adjusted odds ratio = 0.61, 95% confidence interval = 0.46-0.83, P = 0.002). Although RegulomeDB is an attractive tool for predicting the regulatory potential of variants, the two polymorphisms that were selected using RegulomeDB were not associated with lung cancer risk., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Introduction: It has been estimated that the proportion of never-smokers among females with lung cancer is 53% worldwide and 75% in Korea. We conducted a two-stage study to identify genetic factors responsible for lung cancer susceptibility in female never-smokers., Materials and Methods: In a discovery set, 1969 potentially functional single nucleotide polymorphisms (SNPs) of 1151 genes, which were related to cancer development and progression, were evaluated using the Affymetrix custom-made GeneChip in 181 female never-smokers with lung cancer and 179 controls. A replication study was performed on an independent cohort of 596 cases and 1194 healthy controls., Results: Sixteen SNPs with p < 0.05 for genotype distribution in the discovery set were enrolled in the replication study. Among 16 SNPs, three SNPs (colony-stimulating factor 1 receptor [CSF1R] rs10079250A>G, tumor protein p63 [TP63] rs7631358G>A, and corepressor interacting with RBPJ 1 [CIR1] rs13009079T>C) were found to be significantly associated with lung cancer in the same direction as the discovery set. Homology-based model for CSF1R indicated that the rs10079250A>G leads to increased positive charge of CSF-binding region of CSF1R, thereby increasing the chance of binding between CSF and CSF1R. In addition, this SNP was found to increase the phosphorylation of a mitogen-activated protein kinase, JNK., Conclusions: Our results suggest that the three SNPs, particularly CSF1R rs10079250, may contribute to lung cancer susceptibility in never-smoking females.

Telomere shortening leads to genomic instability that drives oncogenesis through the activation of telomerase and the generation of other mutations necessary for tumor progression. This study was conducted to determine the impact of telomere shortening on the survival of patients with early stage non-small cell lung cancer (NSCLC). Relative telomere length in tumor tissues was measured by quantitative polymerase chain reaction in 164 patients with surgically resected NSCLC. The association between telomere length and overall survival (OS) and disease-free survival (DFS) was analyzed. When the patients were categorized into quartiles based on telomere length, those patients with the 1st quartile (shortest) of telomere length had a significantly worse OS and DFS compared to patients with the 2nd to the 4th quartiles of telomere length (adjusted hazard ratio for OS = 2.67, 95% confidence interval = 1.50-4.75, P = 0.001; and adjusted hazard ratio for DFS = 1.92, 95% confidence interval = 1.17-3.14, P = 0.01). An association between telomere length and survival outcome was more pronounced in squamous cell carcinomas than adenocarcinomas (P-value of test for homogeneity for OS and DFS = 0.05 and 0.02, respectively). Telomere length of tumor tissues is an independent prognostic factor in patients with surgically resected early stage NSCLC., (© 2012 Wiley Periodicals, Inc.)

Introduction: MicroRNAs (miRs) play important roles in the development and progression of human cancers. MiR-146a down-regulates epidermal growth factor receptor and the nuclear factor-κB regulatory kinase interleukin-1 receptor-associated kinase 1 genes that play important roles in lung carcinogenesis. This study was conducted to evaluate the association between rs2910164C>G, a functional polymorphism in the pre-miR-146a, and lung cancer risk., Material and Methods: The rs2910164C>G genotypes were determined in 1094 patients with lung cancer and 1100 healthy controls who were frequency matched for age and gender., Results: The rs2910164 CG or GG genotype was associated with a significantly decreased risk for lung cancer compared to that of the CC genotype (adjusted odds ratio=0.80, 95% confidence interval=0.66-0.96, P=0.02). When subjects were stratified according to smoking exposure (never, light and heavy smokers), the effect of the rs2910164C>G genotype on lung cancer risk was significant only in never smokers (adjusted odds ratio=0.66, 95% confidence interval=0.45-0.96, P=0.03, under a dominant model for the C allele) and decreased as smoking exposure level increased (Ptrend<0.001). In line with this result, the level of miR-146a expression in the tumor tissues was significantly higher in the GG genotype than in the CC or CG genotype only in never-smokers (P=0.02)., Conclusions: These findings suggest that the rs2910164C>G in pre-miR-146a may contribute to genetic susceptibility to lung cancer, and that miR-146a might be involved in lung cancer development., (© 2013 Elsevier B.V. All rights reserved.)

This study was conducted to analyze a comprehensive panel of single nucleotide polymorphisms (SNPs) in genes in DNA repair and apoptosis pathways and determine the relationship between polymorphisms and treatment outcomes of patients with non-small cell lung cancer (NSCLC) treated with first-line paclitaxel-cisplatin chemotherapy. Three hundred eighty two patients with NSCLC were enrolled. Seventy-four SNPs in 48 genes (42 SNPs in 27 DNA repair pathway genes and 32 SNPs in 21 apoptotic pathway genes) were genotyped and their associations with chemotherapy response and overall survival (OS) were analyzed. Among SNPs in DNA repair genes, BRCA1 rs799917 was significantly associated with both chemotherapy response and OS. XRCC1 rs25487 exhibited a significant association with chemotherapy response and ERCC2 rs1052555 with OS. Four SNPs in apoptotic genes (TNFRSF1B rs1061624, BCL2 rs2279115, BIRC5 rs9904341, and CASP8 rs3769818) were significantly associated with OS, but not with response to chemotherapy. When the six SNPs which were associated with OS in individual analysis were combined, OS decreased as the number of bad genotypes increased (P(trend) = 2 × 10(-6)). Patients with 3, and 4-6 bad genotypes had significantly worse OS compared with those carrying 0-2 bad genotypes (adjusted hazard ratio [aHR] = 1.54, 95% CI = 1.14-2.08, P = 0.005; aHR = 2.10, 95% CI = 1.55-2.85, P = 2 × 10(-6), respectively). In conclusion, these findings suggest that the six SNPs identified, particularly their combined genotypes, could be used as biomarkers predicting chemotherapy response and survival of NSCLC patients treated with first-line paclitaxel-cisplatin chemotherapy., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

The Rb tumor suppressor gene performs a critical role in controlling cell proliferation and tumorigenesis; it recruits HDAC1 protein into the E2F complexes to repress transcription. In this study, we demonstrate that SNIP1, RB and HDAC1 were significantly expressed in same lung cancer tissues in a tissue microarray (TMA) containing 300 non-small cell lung cancers (NSCLC). High expression level of SNIP1 in tumor patients was significantly correlated with poor prognosis in NSCLC (log-rank P for OS = 0.01, log-rank P for DFS = 0.001). Functionally, SNIP1 competes with HDAC1 for binding to RB and reduces HDAC activity in vitro. Knockdown of SNIP1 reduced colony formation ability of lung cancer cells. These findings may indicate the involvement of SNIP1 in progression of lung cancer by regulating the RB/HDAC1 interaction., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Purpose: This study was conducted to investigate the associations between single-nucleotide polymorphisms (SNP) in 19q13.3 and survival of patients with early-stage non-small cell lung cancer (NSCLC), and to define the causative functional SNP of the association., Experimental Design: A two-stage study design was used to evaluate five SNPs in relation to survival outcomes in 328 patients and then to validate the results in an independent patient population (n = 483). Luciferase assay and real-time PCR were conducted to examine functional relevance of a potentially functional SNP., Results: Of the five SNPs, three SNPs (rs105165C>T, rs967591G>A, and rs735482A>C) were significantly associated with survival outcomes in a stage I study. The rs967591A allele had significantly higher activity of the CD3EAP promoter compared with the rs967591G allele (P = 0.002), but the SNP did not have an effect on the activity of PPP1R13L promoter. The rs967591G>A was associated with the level of CD3EAP mRNA expression in lung tissues (P = 0.01). The rs967591G>A exhibited consistent associations in a stage II study. In combined analysis, the rs967591 AA genotype exhibited a worse overall survival (adjusted HR = 1.69; 95% confidence interval = 1.29-2.20; P = 0.0001)., Conclusion: The rs967591G>A affects CD3EAP expression and thus influences survival in early-stage NSCLC. The analysis of the rs967591G>A polymorphism can help identify patients at high risk of a poor disease outcome., (©2013 AACR.)

Introduction: Liver kinase 1 (LKB1) plays a critical barrier role in lung tumorigenesis by controlling initiation, differentiation and metastasis. We searched for genetic and epigenetic alterations of the LKB1 gene in Korean non-small cell lung cancers (NSCLCs) and correlated the results with clinicopathological features. We also investigated the relationship between genetic and epigenetic alterations of LKB1 and mutations in the TP53 gene and epidermal growth factor receptor (EGFR) pathway genes., Methods: A total of 159 NSCLCs were analyzed for loss of heterozygosity (LOH) at microsatellite loci D19S886, and D19S878. Mutations and methylation status of LKB1 were examined by direct sequencing and a methylation-specific polymerase chain reaction, respectively., Results: A somatic mutation was found in one of the 159 tumors. LOH and promoter methylation was detected in 19.5% (31/159) and 13.2% (21/159) of the tumors, respectively. Four of the 159 tumors had concomitant LOH and methylation of LKB1. In total, 30.2% of the 159 NSCLCs harbored LKB1 LOH or promoter methylation, which were correlated with down-regulation of gene expression. LKB1 LOH was more frequent in males, smokers, and tumors with a TP53 mutation than in females, never-smokers, and tumors without a TP53 mutation, respectively. However, no significant correlation between LKB1 alterations and mutations in EGFR pathway genes was found., Conclusion: These results suggest that the prevalence of LKB1 genetic and epigenetic alterations in NSCLCs vary depending on patient ethnicity. Our results show that LKB1 alterations often occur simultaneously with mutations in EGFR pathway genes., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Introduction: MicroRNAs (miRNAs) are an abundant class of small non-protein-coding RNAs that function as negative gene regulators. Recent evidence indicates that altered miRNA expression plays an important role in the initiation and progression of lung cancer. Single nucleotide polymorphisms (SNPs) in pre-miRNAs could alter miRNAs processing, or expression, and hence, could influence the prognosis of lung cancer. To test this hypothesis, we evaluated the effects of four SNPs in pre-miRNAs (pre-miR-146a rs2910164, pre-miR-149 rs2292832, pre-miR-196a rs11614913, and pre-miR-499 rs3746444) on the survival outcomes of patients with early-stage non-small-cell lung cancer (NSCLC)., Methods: Three hundred sixty-three patients with surgically resected NSCLC were enrolled. The four SNPs were genotyped using a polymerase chain reaction-restriction fragment length polymorphism assay. The genotype associations with overall survival (OS) and disease-free survival (DFS) were analyzed., Results: Of the four SNPs examined, the pre-miR-149 rs2292832T>C and pre-miR-196a rs11614913C>T were found to be significantly associated with OS and DFS. The rs2292832 TC or CC genotype exhibited a significantly better OS and DFS compared with the rs2292832 TT genotype (adjusted hazard ratio [aHR] for OS, 0.66; 95% confidence interval [CI], 0.47-0.92; p = 0.01 and aHR for DFS, 0.64; 95% CI, 0.48-0.87; p = 0.004). For the pre-miR-196a rs11614913C>T, patients with the CT or TT genotype had a significantly better OS and DFS than those with the CC genotype (aHR for OS, 0.70; 95% CI, 0.49-0.99; p = 0.05 and aHR for DFS, 0.66; 95% CI, 0.48-0.90; p = 0.01). When the two SNPs were combined, OS and DFS improved in a dose-dependent manner as the number of good genotypes increased (p = 0.002 and 0.0001, respectively)., Conclusions: These results suggest that miR-149 and miR-196a may be involved in the pathogenesis of NSCLC, and that rs2292832 and rs11614913 can be used as prognostic markers for patients with surgically resected early-stage NSCLC.

Lung cancer in never-smokers ranks as the seventh most common cause of cancer death worldwide, and the incidence of lung cancer in non-smoking Korean women appears to be steadily increasing. To identify the effect of genetic polymorphisms on lung cancer risk in non-smoking Korean women, we conducted a genome-wide association study of Korean female non-smokers with lung cancer. We analyzed 440,794 genotype data of 285 cases and 1,455 controls, and nineteen SNPs were associated with lung cancer development (P < 0.001). For external validation, nineteen SNPs were replicated in another sample set composed of 293 cases and 495 controls, and only rs10187911 on 2p16.3 was significantly associated with lung cancer development (dominant model, OR of TG or GG, 1.58, P = 0.025). We confirmed this SNP again in another replication set composed of 546 cases and 744 controls (recessive model, OR of GG, 1.32, P = 0.027). OR and P value in combined set were 1.37 and < 0.001 in additive model, 1.51 and < 0.001 in dominant model, and 1.54 and < 0.001 in recessive model. The effect of this SNP was found to be consistent only in adenocarcinoma patients (1.36 and < 0.001 in additive model, 1.49 and < 0.001 in dominant model, and 1.54 and < 0.001 in recessive model). Furthermore, after imputation with HapMap data, we found regional significance near rs10187911, and five SNPs showed P value less than that of rs10187911 (rs12478012, rs4377361, rs13005521, rs12475464, and rs7564130). Therefore, we concluded that a region on chromosome 2 is significantly associated with lung cancer risk in Korean non-smoking women.

A genome-wide association study has identified the 15q25 region as being associated with the risk of chronic obstructive pulmonary disease (COPD) in Caucasians. This study intended as a confirmatory assessment of this association in a Korean population. The rs6495309C > T polymorphism in the promoter of nicotinic acetylcholine receptor alpha subunit 3 (CHRNA3) gene was investigated in a case-control study that consisted of 406 patients with COPD and 394 healthy control subjects. The rs6495309 CT or TT genotype was associated with a significantly decreased risk of COPD when compared to the rs6495309 CC genotype (adjusted odds ratio = 0.69, 95% confidence interval = 0.50-0.95, P = 0.023). The effect of the rs6495309C > T on the risk of COPD was more evident in moderate to very severe COPD than in mild COPD under a dominant model for the variant T allele (P = 0.024 for homogeneity). The CHRNA3 rs6495309C > T polymorphism on chromosome 15q25 is associated with the risk of COPD in a Korean population.

To identify common genetic variants that contribute to lung cancer susceptibility, we conducted a multistage genome-wide association study of lung cancer in Asian women who never smoked. We scanned 5,510 never-smoking female lung cancer cases and 4,544 controls drawn from 14 studies from mainland China, South Korea, Japan, Singapore, Taiwan and Hong Kong. We genotyped the most promising variants (associated at P < 5 × 10(-6)) in an additional 1,099 cases and 2,913 controls. We identified three new susceptibility loci at 10q25.2 (rs7086803, P = 3.54 × 10(-18)), 6q22.2 (rs9387478, P = 4.14 × 10(-10)) and 6p21.32 (rs2395185, P = 9.51 × 10(-9)). We also confirmed associations reported for loci at 5p15.33 and 3q28 and a recently reported finding at 17q24.3. We observed no evidence of association for lung cancer at 15q25 in never-smoking women in Asia, providing strong evidence that this locus is not associated with lung cancer independent of smoking.

Background and Objective: Genome-wide association studies (GWAS) have identified the three chromosomal regions, 5p15, 6p21 and 15q25, as being associated with lung cancer risk in European populations. This study was performed to confirm these associations in Korean patients with lung cancer., Methods: The genotypes at rs2736100, rs402710, rs401681 and rs31489 at 5p15, rs9295740 at 6p22, which is in extensive linkage disequilibrium with the 6p21 region, as well as rs2036534 and rs6495309 at 15q25, were determined in 1094 patients with lung cancer and 1100 healthy control subjects, who were frequency matched for age and gender., Results: The single-nucleotide polymorphisms (SNP) at 5p15 (rs2736100, adjusted odds ratio [aOR] 1.32, 95% confidence interval [CI] 1.03-1.67, P = 0.025; rs402710, aOR 0.82, 95% CI 0.69-0.98, P = 0.025; rs401681, aOR 0.82, 95% CI 0.69-0.98, P = 0.026) and at 15q25 (rs2036534, aOR 0.75, 95% CI 0.61-0.93, P = 0.01; rs6495309, aOR 0.81, 95% CI 0.65-1.00, P = 0.052) were significantly associated with lung cancer risk. The magnitude of the effect was similar to that reported in previous studies, and the association was in the same direction. The effect of SNP in the 5p15 region on the risk of lung cancer was significant only for adenocarcinoma. The two SNP in the 15q25 region were significantly associated with lung cancer risk in ever-smokers and in patients with squamous-cell carcinoma. However, there was no association between the SNP at 6p22 and lung cancer risk., Conclusions: The association between SNP in the 5p15 and 15q25 regions and the risk of lung cancer was confirmed in a Korean population., (© 2012 The Authors. Respirology © 2012 Asian Pacific Society of Respirology.)

Telomerase play a key role in the maintenance of telomere length and chromosome integrity. We have evaluated the association between telomerase activity and the risk of lung cancer in peripheral blood. Telomerase activity in peripheral blood mononuclear cells was measured by a PCR-designed telomeric repeat amplification protocol in 63 lung cancer patients and 190 healthy controls that were matched for age, gender, and smoking status. Telomerase activity was significantly lower in the lung cancer patients than in controls (mean ± standard deviation; 1.32 ± 1.65 vs 2.60 ± 3.09, P < 1 × 10(-4)). When telomerase activity was categorized into quartiles based on telomerase activity in the controls, the risk of lung cancer increased as telomerase activity reduced (P(trend) = 1 × 10(-4)). Moreover, when the subjects were categorized based on the median value of telomerase activity, subjects with low telomerase activity were at a significantly increased risk of lung cancer compared to subjects with high telomerase activity (adjusted odds ratio = 3.05, 95% confidence interval = 1.60-5.82, P = 7 × 10(-4)). These findings suggest that telomerase activity may affect telomere maintenance, thereby contributing to susceptibility to lung cancer.

This study was conducted to identify genetic factors predisposing to TP53 mutations in patients with non-small cell lung cancer (NSCLC). A comprehensive panel of potentially functional single nucleotide polymorphisms (SNPs) in DNA repair genes was evaluated in relation to TP53 mutations. Thirty-seven SNPs in 28 DNA repair genes were genotyped by a sequenome mass spectrometry-based genotyping assay in 173 NSCLCs and the associations with TP53 mutations in the entire coding exons (exons 2-11), including splicing sites of the gene, were analyzed. Four SNPs (XPA rs1800975, OGG1 rs1052133, ADPRT rs1136410, and NBS1 rs1805794) were significantly associated with the prevalence of TP53 mutations in multivariate analysis for each SNP. When the 4 SNPs were combined, the prevalence of TP53 mutations was increased as the number of bad genotypes increased (P(trend)=0.001). Patients with 3 and 4 bad genotypes had a significantly higher frequency of TP53 mutations than those with 0-1 bad genotypes (adjusted odds ratio=5.18, 95% confidence interval=1.51-17.81, P=0.01 and adjusted odds ratio=18.26, 95% confidence interval=2.87-116.09, P=0.002, respectively). These findings suggest that the 4 SNPs may modulate the occurrence of TP53 mutations and contribute to lung carcinogenesis. However, larger studies are required to confirm our findings in other ethnic populations., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

This study was conducted to determine the impact of a functional tandem repeat minisatellite (MNS16A) polymorphism in the telomerase reverse transcriptase (TERT) gene on the risk of lung cancer, as well as on survival of patients with non-small-cell lung cancer (NSCLC). The effect of the MNS16A variable number of tandem repeat (VNTR) polymorphism on the risk of lung cancer was evaluated in a case-control study that consisted of 937 lung cancer patients and 943 healthy controls. The effect of the polymorphism on survival outcome was evaluated in 703 patients with surgically resected NSCLC. Compared with the VNTR-302 allele, the VNTR-243 allele was associated with a significantly increased risk of lung cancer (adjusted odds ratio, 1.55; 95% confidence interval [CI], 1.07-2.25; P = 0.02). In addition, the genotypes carrying at least one VNTR-243 allele were associated with a significantly increased risk of lung cancer compared with the genotypes with no VNTR-243 allele (adjusted odds ratio, 1.61; 95% CI, 1.09-2.38; P = 0.02). In contrast to the effect of the polymorphism on the risk of lung cancer, the genotypes carrying at least one VNTR-243 allele were associated with a significantly better overall survival in patients with surgically resected NSCLC (adjusted hazard ratio, 0.51; 95% CI, 0.28-0.93; P = 0.03). These findings suggest that the MNS16A VNTR polymorphism in the TERT gene has dual, conflicting roles in lung carcinogenesis. This polymorphism may increase the risk of lung cancer development, and may improve survival in lung cancer patients., (© 2010 Japanese Cancer Association.)

This study was conducted to analyze a comprehensive panel of single nucleotide polymorphisms (SNP) in DNA repair genes to determine the relationship between polymorphisms and the survival outcome of patients with early stage non-small-cell lung cancer (NSCLC). Three hundred and ten consecutive patients with surgically resected NSCLC were enrolled. Forty-eight SNP in 27 DNA repair genes were genotyped and their associations with overall survival (OS) and disease-free survival (DFS) were analyzed. Individually, six SNP exhibited significant associations with survival outcome. When the six SNP were combined, OS and DFS decreased as the number of bad genotypes increased (P(trend) <0.0001 for both). Patients with three, and four or five bad genotypes had a significantly worse OS and DFS compared with those carrying zero or one bad genotypes (adjusted hazard ratio [aHR] for OS=3.53, 95% confidence interval [CI]=1.25-9.97, P=0.02, and aHR for DFS=3.31, 95% CI=1.41-7.76, P=0.006; and aHR for OS=5.47, 95% CI=1.87-16.00, P=0.002, and aHR for DFS=4.42, 95% CI=1.82-10.74, P=0.001, respectively). These findings suggest that the six SNP identified can be used as prognostic markers for patients with surgically resected early stage NSCLC., (© 2010 Japanese Cancer Association.)

Based on the important role of microRNA (miRNA) biosynthesis genes in carcinogenesis, we hypothesized that polymorphisms in the miRNA biosynthesis genes may modulate susceptibility to lung cancer. To test this hypothesis, we conducted a two-stage study to evaluate the associations between single nucleotide polymorphisms (SNPs) in the miRNA biosynthesis genes and the risk of lung cancer. In stage 1 of the study, 24 SNPs in the 11 miRNA biosynthesis genes (DROSHA, DGCR8, RAN, XPO5, DICER, AGO1, AGO2, HIWI, GEMIN3, GEMIN4, and TRBP) were genotyped in 100 lung cancer patients and 100 healthy controls using a sequenome mass spectrometry-based genotyping assay. One promising SNP (AGO1 rs636832A > G) was selected for stage 2 of the study, and genotyped by a melting-curve analysis using fluorescence-labeled hybridization probes in an independent set of 552 cases and 552 controls. The AGO1 rs636832A > G exhibited highly consistent results between the two stages of the study. In combined analysis, the 636832A > G was associated with a significantly decreased risk of lung cancer in a dose-dependent manner (P(trend) = 6.0 × 10(-4)). Individuals with at least one rs636832G allele were at a significantly decreased risk of lung cancer compared with those with the AA genotype (adjusted odds ratio = 0.67, 95% confidence interval = 0.53-0.84, P = 4.0 × 10(-4)). This finding suggests that the AGO1 rs636832A > G might be a useful marker for determining the susceptibility to lung cancer and that the AGO1 gene might be involved in the development of lung cancer., (© 2010 Wiley-Liss, Inc.)

Purpose: This study was conducted to determine the association between single-nucleotide polymorphisms (SNPs) in apoptosis-related genes and survival outcomes of patients with early-stage non-small-cell lung cancer (NSCLC)., Methods: Three hundred ten consecutive patients with surgically resected NSCLC were enrolled. Twenty-five SNPs in 17 apoptosis-related genes were genotyped by a sequenome mass spectrometry-based genotyping assay. The genotype associations with overall survival (OS) and disease-free survival (DFS) were analyzed., Results: Three SNPs (TNFRSF10B rs1047266, TNFRSF1A rs4149570, and PPP1R13L rs1005165) were significantly associated with survival outcomes on multivariate analysis. When the three SNPs were combined, OS and DFS were decreased as the number of bad genotypes increased (P (trend) for OS and DFS = 7 × 10(-5) and 1 × 10(-4), respectively). Patients with one bad genotype, and patients with two or three bad genotypes had significantly worse OS and DFS compared with those with no bad genotypes [adjusted hazard ratio (aHR) for OS = 2.27, 95% confidence interval (CI) = 1.22-4.21, P = 0.01, aHR for DFS = 1.74, 95% CI = 1.08-2.81, P = 0.02; aHR for OS = 4.11, 95% CI = 2.03-8.29, P = 8 × 10(-5); and aHR for DFS = 2.89, 95% CI = 1.64-5.11, P = 3 × 10(-4), respectively]., Conclusion: Three SNPs in apoptosis-related genes were identified as possible prognostic markers of survival in patients with early-stage NSCLC. The SNPs, and particularly their combined genotypes, can be used to identify patients at high risk for poor disease outcome.

Although shortened telomeres have been found in many cancers, elongated telomere length has been observed as an early response after low-dose treatment with various chemical carcinogens in vitro and animal experiments, suggesting low-dose exposure to carcinogenic chemicals may function as a tumour promoter at the very early stage of carcinogenesis in humans. This cross-sectional study was performed to examine whether low-dose exposure to persistent organic pollutants (POPs), lipophilic xenobiotics that mainly bioaccumulate in adipose tissue, is associated with telomere length of peripheral blood leukocytes in apparently healthy persons. Telomere length was measured using quantitative polymerase chain reaction method in 84 apparently healthy Koreans. Among various POPs, serum concentrations of organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs) and polybrominated diphenylethers were measured. Most OC pesticides and PCBs were positively and significantly associated with telomere length with correlation coefficients from about +0.25 to +0.35. The strongest associations were observed with p,p'-dichlorodiphenyldichloroethylene, PCB99, PCB153, PCB180, PCB183 and PCB187. When we examined adjusted means of telomere length by quintiles of POPs, the steeper increases of telomere length tended to be observed within relatively lower ranges of POPs. Besides serum concentrations of POPs, none of the other variables studied, including age, were associated with telomere length in this study. We found that telomere length was increasing across low doses of exposure to POPs in which the majority of study subjects were found, suggesting that low-dose POPs may act as a tumour promoter in carcinogenesis in humans.

Introduction: Caspases (CASPs) are important regulators and executioners in apoptosis pathway and play a crucial role in the development and progression of cancer. On the basis of the interactions of CASPs in the apoptotic pathway, we evaluated the association between 11 polymorphisms of CASP3, 6, 7, 8, 9, and 10 genes and the risk of lung cancer., Methods: The genotypes were determined in 720 patients with lung cancer and 720 healthy controls frequency matched for age and gender., Results: In individual polymorphism analysis, the CASP7 rs2227310C>G and CASP9 rs4645981C>T were associated with 1.40-fold and 1.28-fold increased risk of lung cancer under recessive and dominant models for the variant allele of each polymorphism, respectively. In the case of the CASP3 77G>A, subjects with the GG genotype were at a 1.19-fold increased risk of lung cancer compared with those with at least one variant allele. When the three polymorphisms were combined, the risk of lung cancer increased in a dose-dependent manner as the number of risk genotypes increased (ptrend <0.001). Subjects with two and three risk genotypes carried a significantly increased risk of lung cancer compared with those with zero risk genotype (adjusted odds ratio = 1.56, 95% confidence interval = 1.14-2.13, p = 0.005 and adjusted odds ratio = 2.54, 95% confidence interval = 1.28-5.02, p = 0.008, respectively)., Conclusions: These results suggest that a combined analysis of these three CASP gene polymorphisms might better predict the risk of lung cancer than analysis of a single polymorphism.

Background: Although a few studies have been conducted to evaluate the association of polymorphisms in matrix metalloproteinase (MMP) genes with chronic obstructive pulmonary disease (COPD), the results have been inconsistent., Objectives: To investigate the association of 3 polymorphisms of MMP genes (MMP-1 -1607G-->GG, MMP-9 -1562C-->T and MMP-12 N357S), which have been reported to be associated with COPD-related phenotypes, with the risk of COPD in a Korean population., Methods: The genotypes of the 3 polymorphisms were determined in 301 patients with COPD and 333 healthy controls., Results: Of the 3 polymorphisms studied, only the distribution of the MMP-9 -1562C-->T genotypes was significantly different between the cases and controls (p = 0.01), with the frequency of the variant T allele being significantly lower in the cases than in the controls (10.4 vs. 15.7%; p = 0.006). Individuals with at least 1 variant T allele were at a significantly decreased risk of COPD when compared with those with homozygous wild-type alleles (adjusted odds ratio = 0.69; 95% CI = 0.45-0.98; p = 0.04)., Conclusions: These findings suggest that the MMP-9 -1562C-->T polymorphism could be used as a marker for determining the genetic susceptibility to COPD in a Korean population., (Copyright 2010 S. Karger AG, Basel.)

Purpose: This study was conducted to determine the impact of potentially functional polymorphisms in the CASPASE (CASP) genes on the survival of early-stage non-small-cell lung cancer (NSCLC) patients., Patients and Methods: Four hundred eleven consecutive patients with surgically resected NSCLC were enrolled. Nine potentially functional polymorphisms in the CASP3, CASP7, CASP8, CASP9, and CASP10 genes were investigated. The genotype and haplotype associations with overall survival (OS) and disease-free survival (DFS) were analyzed., Results: Patients with the rs2227310 GG genotype had a significantly decreased OS and DFS compared with patients with the CC + CG genotype (adjusted hazard ratio [aHR] for OS, 1.67; 95% CI, 1.19 to 2.35; P = .003; aHR for DFS, 1.62; 95% CI, 1.19 to 2.22; P = .002). The rs4645981C>T genotype also had a significant effect on OS and DFS (under a recessive model; aHR for OS, 2.00; 95% CI, 1.04 to 3.85; P = .04; aHR for DFS, 2.76; 95% CI, 1.58 to 4.80; P = .0003). When the rs2227310 and rs4645981 genotypes were combined, patients with one or two bad genotypes had worse OS and DFS compared with those who had zero bad genotypes (aHR for OS, 1.75; 95% CI, 1.25 to 2.45; P = .001; aHR for DFS, 1.66; 95% CI, 1.23 to 2.26; P = .001)., Conclusion: The CASP7 rs2227310 and CASP9 rs4645981 polymorphisms may affect survival in early-stage NSCLC. The analysis of these polymorphisms can help identify patients at high risk for a poor disease outcome.

This study was conducted to comprehensively evaluate the associations between polymorphisms in telomere maintenance genes (TERT, TRF1, TNKS1, TRF2, RAP1, and POT1) and lung cancer risk. We captured 35 polymorphisms in the genes and determined their frequencies in 27 healthy Koreans. Ten haplotype-tagging polymorphisms were examined in a case-control study that consisted of 720 lung cancer patients and 720 healthy controls. The TERT rs2735940 g.C > T and rs2736098 g.G > A, and TNKS1 rs6985140 g.A > G were significantly associated with the risk of lung cancer. In the haplotype analysis, the TERT rs2735940T/rs2736098A haplotype (ht4) was associated with a significantly increased risk of lung cancer compared with the rs2735940C/rs2736098G haplotype (adjusted odds ratio, 1.26; 95% confidence interval, 1.07-1.50; P = 0.008). When the TERT ht4 and TNKS1 rs6985140G as risk alleles, the risk of lung cancer increased in a dose-dependent manner as the number of risk alleles increased (P(trend) < 0.001). Subjects with two to four risk alleles were at a significantly increased risk of lung cancer (adjusted odds ratio, 1.67; 95% confidence interval, 1.23-2.27; P = 0.001) compared with subjects with zero risk allele. These findings suggest that genetic variants in the TERT and TNKS1 genes contribute to genetic susceptibility to lung cancer.

Telomeres play a key role in the maintenance of chromosome integrity and stability. There is growing evidence that short telomeres induce chromosome instability and thereby promote the development of cancer. We investigated the association of telomere length and the risk of lung cancer. Relative telomere length in peripheral blood lymphocytes was measured by quantitative polymerase chain reaction in 243 lung cancer patients and 243 healthy controls that were frequency-matched for age, sex and smoking status. Telomere length was significantly shorter in lung cancer patients than in controls (mean +/- standard deviation: 1.59 +/- 0.75 versus 2.16 +/- 1.10, P < 0.0001). When the subjects were categorized into quartiles based on telomere length, the risk of lung cancer was found to increase as telomere length shortened (P(trend) < 0.0001). In addition, when the median of telomere length was used as the cutoff between long and short telomeres, individuals with short telomeres were at a significantly higher risk of lung cancer than those with long telomeres (adjusted odds ratio = 3.15, 95% confidence interval = 2.12-4.67, P < 0.0001). When the cases were categorized by tumor histology, the effect of short telomere length on the risk of lung cancer was more pronounced in patients with small cell carcinoma than in those with squamous cell carcinoma and adenocarcinoma (P = 0.001, test for homogeneity). These findings suggest that shortening of the telomeres may be a risk factor for lung cancer, and therefore, the presence of shortened telomeres may be used as a marker for susceptibility to lung cancer.

The purpose of this study is to comprehensively evaluate potential functional polymorphisms in the P21 gene in relation to the risk of lung cancer. We first determined the frequencies of P21 polymorphisms in 27 healthy Koreans, and then examined three polymorphisms (-2266G > A, S31R, and IVS2 + 16G > C), based on their frequencies and haplotype-tagging status, in a case-control study. Individuals with at least one -2266A allele were at a significantly decreased risk of lung cancer compared with those harboring the -2266 GG genotype [adjusted odds ratio (OR) = 0.71, 95% confidence interval (CI) = 0.53-0.95, P = 0.02). The haplotypes (ht2-4) carrying 31R or IVS2 + 16C alleles were associated with a significantly decreased risk of lung cancer compared with the haplotype 31S/IVS2 + 16G, which carried wild-type alleles at both loci (adjusted OR = 0.65, 95% CI = 0.50-0.83, P = 0.007)]. When the -2266A allele and ht2-4 were considered to be protective alleles, the risk of lung cancer decreased in a dose-dependent manner as the number of protective alleles increased (P = 0.0002). These results suggest that a combined analysis of these three P21 polymorphisms might better predict the risk of lung cancer than the analysis of a single polymorphism.