hOGG1, p53 genes, and smoking interactions are associated with the development of lung cancer

Association between p73 G4C14-to-A4T14 polymorphism and lung cancer risk: A systematic review and meta-analysis

OBJECTIVE

This study was conducted to evaluate the relationship between the p73 G4C14-to-A4T14 polymorphism (hereafter, G4C14-to-A4T14) and lung cancer risk.

METHODS

The studies on the relationship between G4C14-A4T14 and lung cancer risk published as of November 5, 2018, were comprehensively searched in PubMed, Embase, the Cochrane Library, the Chinese Wanfang database, China National Knowledge Infrastructure (CNKI), and China Biology Medicine (CBM). The last update was on May 24, 2019. Statistical analysis was performed using Stata 12.0.

RESULTS

The association between G4C14-A4T14 and lung cancer risk was analyzed in nine studies. The findings indicate no association between G4C14-to-A4T14 and lung cancer risk (allele model: OR = 0.90, 95% CI: 0.73-1.11, I²  = 86.0%, P = .330; dominant model: OR = 0.93, 95% CI: 0.74-1.17, I²  = 82.6%, P = .551; recessive model: OR = 0.75, 95% CI: 0.50-1.13, I²  = 75.2%, P = .165; homozygote model: OR = 0.74, 95% CI: 0.47-1.17, I²  = 79.6%, P = .199; heterozygote model: OR = 0.98, 95% CI: 0.80-1.21, I²  = 75.8%, P = .879). The heterogeneity between subgroups by cancer types and genotyping method was significantly reduced. After the deletion of suspected duplicates, no association was found between G4C14-to-A4T14 and lung cancer susceptibility.

CONCLUSION

Our meta-analysis confirms that G4C14-to-A4T14 is not significantly related to lung cancer risk.

Construction of a 26‑feature gene support vector machine classifier for smoking and non‑smoking lung adenocarcinoma sample classification

The present study aimed to identify the feature genes associated with smoking in lung adenocarcinoma (LAC) samples and explore the underlying mechanism. Three gene expression datasets of LAC samples were downloaded from the Gene Expression Omnibus database through pre-set criteria and the expression data were processed using meta-analysis. Differentially expressed genes (DEGs) between LAC samples of smokers and non-smokers were identified using limma package in R. The classification accuracy of selected DEGs were visualized using hierarchical clustering analysis in R language. A protein-protein interaction (PPI) network was constructed using gene interaction data from the Human Protein Reference Database for the DEGs. Betweenness centrality was calculated for each node in the network and genes with the greatest BC values were utilized for the construction of the support vector machine (SVM) classifier. The dataset GSE43458 was used as the training dataset for the construction and the other datasets (GSE12667 and GSE10072) were used as the validation datasets. The classification accuracy of the classifier was tested using sensitivity, specificity, positive predictive value, negative predictive value and area under curve parameters with the pROC package in R language. The feature genes in the SVM classifier were subjected to pathway enrichment analysis using Fisher's exact test. A total of 347 genes were identified to be differentially expressed between samples of smokers and non-smokers. The PPI network of DEGs were comprised of 202 nodes and 300 edges. An SVM classifier comprised of 26 feature genes was constructed to distinguish between different LAC samples, with prediction accuracies for the GSE43458, GSE12667 and GSE10072 datasets of 100, 100 and 94.83%, respectively. Furthermore, the 26 feature genes that were significantly enriched in 9 overrepresented biological pathways, including extracellular matrix-receptor interaction, proteoglycans in cancer, cell adhesion molecules, p53 signaling pathway, microRNAs in cancer and apoptosis, were identified to be smoking-related genes in LAC. In conclusion, an SVM classifier with a high prediction accuracy for smoking and non-smoking samples was obtained. The genes in the classifier may likely be the potential feature genes associated with the development of patients with LAC who smoke.

Association of p73 gene G4C14-A4T14 polymorphism and MDM2 gene SNP309 with non-small cell lung cancer risk in a Chinese population

The present study aimed to investigate the association of p73 G4C14-A4T14 polymorphism and murine double minute 2 (MDM2) 309 T/G single nucleotide polymorphisms (SNPs) with the risk of developing non-small cell lung cancer (NSCLC) in Sothern China. The p73 and MDM2 genotypes of peripheral blood DNA from 186 patients with NSCLC and 196 normal controls were detected by polymerase chain reaction (PCR) with confronting two-pair primers (CTPP) and high resolution melting (HRM), respectively. The results of genotyping were consistent with those of direct sequencing. The p73 AT/AT [odds ratio (OR)=0.46; 95% confidence interval (CI)=0.22-0.97] and MDM2 TT (OR=0.48; 95% CI=0.26-0.86) genotypes were associated with a decreased risk of developing NSCLC compared with that of the p73 GC/GC and MDM2 GG genotypes, respectively. In addition, the interaction between the p73 and MDM2 polymorphisms reduced the risk of developing NSCLC in multiple ways (OR=0.13; 95% CI=0.03-0.59) for subjects carrying both the p73 AT/AT and MDM2 TT genotypes. Therefore, the SNP in p73 G4C14-A4T14 and the MDM2 309 polymorphism may be markers of genetic susceptibility to NSCLC in a Chinese population, and there is a possible gene-gene interaction involved in the incidence of NSCLC.

Association of XRCC1 Arg399GIn and Tp53 Arg72Pro polymorphisms and increased risk of uterine leiomyoma - A case-control study

The aim of present study was to investigate the role of the X-ray repair cross-complementing protein1 (XRCC1) and Tumor protein p53 (Tp53) polymorphisms in Uterine Leiomyoma (UL) susceptibility in southeastern Iran. This case control study was performed on 139 women with UL and 149 age, BMI and ethnicity matched healthy women. All women were genotyped for the XRCC1 Arg399Gln, XRCC1 Arg194Trp and Tp53 Arg72Pro polymorphisms. The frequency of Tp53 72 Pro/Pro genotype was significantly higher in UL women compared to controls. The risk of UL was 1.5 fold higher in women with the Pro/Pro genotype (OR, 1.5 [95% CI, 1.1 to 2.1], p = 0.012). Moreover, the frequency of the Pro allele was significantly higher in the UL women. Although the frequency of XRCC1 Arg399Gln genotypes did not significantly differ between UL and control groups before adjusting for age, there was an association between the XRCC1 Arg/Gln genotype and UL after adjusting for age (OR, 1.8 [95% CI, 1.1 to 3]). No association was observed between the XRCC1 Arg194Trp polymorphism and UL. The Pro/Pro genotype of Tp53 Arg72Pro polymorphism was associated with UL susceptibility. In addition, the XRCC1 Arg/Gln genotype was associated with increased risk of UL after adjusting for age.

Association of methylation of the RAR-β gene with cigarette smoking in non-small cell lung cancer with Southern-Central Chinese population

Pathogenesis of lung cancer is a complicated biological process including multiple genetic and epigenetic changes. Since cigarette smoking is confirmed as the most main risk factor of non-small cell lung cancer (NSCLC), the aim of this study was to determine whether tobacco exposure plays a role in gene methylation. Methylation of the RAR-β gene were detected using methylation-specific polymerase chain reaction in DNA from 167 newly diagnosed cases with NSCLC and corresponding 105 controls. A significant statistical association was found in the detection rate of the promoter methylation of RAR-β gene between NSCLC and controls (x2=166.01; p<0.01), and hypermethylation of the RAR-β gene was significantly associated with smoking status (p=0.038, p<0.05). No relationship was found between RAR-β gene methylation and pathologic staging including clinical stage, cell type, gender and drinking (p>0.05), and the methylation of RAR-β gene rate of NSCLC was slightly higher in stages III+IV (80.0%) than in I+II (70.8%). Similar results were obtained for methylation of the RAR-β gene between squamous cell carcinoma (77.9%) and other cell type lung cancer (73.9%). These results showed that the frequency of methylation increased gradually with the development of clinical stage in smoking-associated lung cancer patients, and tobacco smoke may be play a potential role in RAR-β gene methylation in the early pathogenesis and process in lung cancer, particularly squamous cell carcinoma. Aberrant promoter methylation is considered to be a promising marker of previous carcinogen exposure and cancer risk.

Association of a p53 codon 72 gene polymorphism with environmental factors and risk of lung cancer: a case control study in Mizoram and Manipur, a high incidence region in North East India

BACKGROUND

A very high incidence of lung cancer is observed in Mizoram and Manipur, North East India. We conducted a population based case control study to establish associations of p53 codon 72 polymorphisms and interactions with environmental factors for this high incidence.

MATERIAL AND METHODS

A total of 272 lung cancer cases and 544 controls matched for age (±5 years), sex and ethnicity were collected and p53 codon 72 polymorphism genotypes were analyzed using a polymerase chain based restriction fragment length polymorphism assay. We used conditional multiple logistic regression analysis to calculate adjusted odds ratios and 95% confidence intervals after adjusting for confounding factors.

RESULTS

p53 Pro/Pro genotype was significantly associated with increased risk of lung cancer in the study population (adjusted OR=2.14, CI=1.35-3.38, p=0.001). Interactions of the p53 Pro/Pro genotype with exposure to wood smoke (adjusted OR=3.60, CI=1.85-6.98, p<0.001) and cooking oil fumes (adjusted OR=3.27, CI=1.55-6.87, p=0.002), betel quid chewing (adjusted OR=3.85, CI=1.96- 7.55, p<0.001), tobacco smoking (adjusted OR=4.42, CI=2.27-8.63, p<0.001) and alcohol consumption (adjusted OR=3.31, CI=1.10-10.03, p=0.034) were significant regarding the increased risk of lung cancer in the study population.

CONCLUSIONS

The present study provided preliminary evidence that a p53 codon 72 polymorphism may effect lung cancer risk in the study population, interacting synergistically with environmental factors.

Association between a p73 gene polymorphism and genetic susceptibility to non-small cell lung cancer in the South of China

BACKGROUND

This study aimed to identify any association between the p73 gene G4C14-to-A4T14 polymorphism and risk of non-small cell lung cancer (NSCLC) in the south of China.

MATERIALS AND METHODS

We genotyped the p73 gene polymorphism of peripheral blood DNA from 168 patients with NSCLC and 195 normal controls using HRM (high resolution melting) and PCR-CTPP (polymerase chain reaction with confronting two-pair primers).

RESULTS

The results of genotyping by HRM and PCR-CTPP were consistent with direct sequencing, the p73 genotype distribution in 168 lung cancer patients being as follows: GC/GC 101 cases (60.1%), GC/ AT 59 cases (35.1%), AT/AT 8 cases (4.8%). The carriers of AT/AT genotype had a significantly reduced risk of NSCLC (OR=0.370; 95%CI: 0.170-0.806; p=0.010) as compared with non-carriers. However, we found no relations between p73 genotypes and histological type (p=0.798, x2=0.452), tumor stage (p=0.806, x2=0.806), or lymph node metastasis (p=0.578, x2=1.098).

CONCLUSIONS

Our findings suggest that the p73 G4C14-to-A4T14 polymorphism may be a modifier of NSCLC susceptibility in the Chinese population.

hOGG1 C1245G gene polymorphism associated with prostate cancer: a meta-analysis

BACKGROUND

Prostate cancer (Pca) is one of the most frequently encountered multifactorial malignant diseases worldwide. The human oxoguanine glycosylase 1 (hOGG1) C1245G polymorphism (rs1052133) has been found to be associated with Pca. However, the conclusions have been controversial.

METHODS

Based on the PubMed, Embase, HuGENet and Chinese National Knowledge Infrastructure (CNKI) databases, this meta-analysis was conducted with 4 models. Eleven qualified studies were included.

RESULTS

Although no positive relation was discovered in the pooled analysis, significant associations between rs1052133 and Pca were found in the Asian population (recessive: odds ratio [OR] = 1.580, 95% confidence interval [95% CI], 1.189-2.098; GG vs. GC: OR = 1.504, 95% CI, 1.114-2.030; GG vs. CC: OR = 1.677, 95% CI, 1.201-2.342; allele analysis: OR = 1.249, 95% CI, 1.077-1.449), whites (dominant: OR = 2.138, 95% CI, 1.483-3.083; recessive: OR = 3.143, 95% CI, 1.171-8.437; GG vs. CC: OR = 3.992, 95% CI, 1.891-8.431; allele analysis: OR = 1.947, 95% CI, 1.467-2.586) and mixed populations (recessive: OR = 0.636, 95% CI, 0.484-0.834; GG vs. GC: OR = 0.654, 95% CI, 0.492-0.871; GG vs. CC: OR = 0.624, 95% CI, 0.473-0.823; allele analysis: OR = 0.857, 95% CI, 0.771-0.954). After excluding studies deviating from the Hardy-Weinberg equilibrium, a significant association was also found in the same ethnic groups. In addition, a new positive relation was identified in the "other country" subgroup (with China, South Korea and Australia included) (dominant: OR = 1.622, 95% CI, 1.163-2.261; recessive: OR = 1.773, 95% CI, 1.308-2.404; GG vs. GC: OR = 1.614, 95% CI, 1.169-2.230; GG vs. CC: OR = 2.108, 95% CI, 1.456-3.051; allele analysis: OR = 1.494, 95% CI, 1.235-1.808) and among the Chinese-Korean population.

CONCLUSIONS

In conclusion, we suggest that the hOGG1 C1245G polymorphism might be potentially associated with Pca risk in different ethnicities and countries, especially among Asians. Further studies are needed to confirm these relations.

OGG1 Mutations and Risk of Female Breast Cancer: Meta-Analysis and Experimental Data

In first part of this study association between OGG1 polymorphisms and breast cancer susceptibility was explored by meta-analysis. Second part of the study involved 925 subjects, used for mutational analysis of OGG1 gene using PCR-SSCP and sequencing. Fifteen mutations were observed, which included five intronic mutations, four splice site mutations, two 3'UTR mutations, three missense mutations, and a nonsense mutation. Significantly (p < 0.001) increased (~29 fold) breast cancer risk was associated with a splice site variant g.9800972T>G and 3'UTR variant g.9798848G>A. Among intronic mutations, highest (~15 fold) increase in breast cancer risk was associated with g.9793680G>A (p < 0.009). Similarly ~14-fold increased risk was associated with Val159Gly (p < 0.01), ~17-fold with Gly221Arg (p < 0.005), and ~18-fold with Ser326Cys (p < 0.004) in breast cancer patients compared with controls, whereas analysis of nonsense mutation showed that ~13-fold (p < 0.01) increased breast cancer risk was associated with Trp375STOP in patients compared to controls. In conclusion, a significant association was observed between OGG1 germ line mutations and breast cancer risk. These findings provide evidence that OGG1 may prove to be a good candidate of better diagnosis, treatment, and prevention of breast cancer.

A genome-wide gene-environment interaction analysis for tobacco smoke and lung cancer susceptibility

Tobacco smoke is the major environmental risk factor underlying lung carcinogenesis. However, approximately one-tenth smokers develop lung cancer in their lifetime indicating there is significant individual variation in susceptibility to lung cancer. And, the reasons for this are largely unknown. In particular, the genetic variants discovered in genome-wide association studies (GWAS) account for only a small fraction of the phenotypic variations for lung cancer, and gene-environment interactions are thought to explain the missing fraction of disease heritability. The ability to identify smokers at high risk of developing cancer has substantial preventive implications. Thus, we undertook a gene-smoking interaction analysis in a GWAS of lung cancer in Han Chinese population using a two-phase designed case-control study. In the discovery phase, we evaluated all pair-wise (591 370) gene-smoking interactions in 5408 subjects (2331 cases and 3077 controls) using a logistic regression model with covariate adjustment. In the replication phase, promising interactions were validated in an independent population of 3023 subjects (1534 cases and 1489 controls). We identified interactions between two single nucleotide polymorphisms and smoking. The interaction P values are 6.73 × 10(-) (6) and 3.84 × 10(-) (6) for rs1316298 and rs4589502, respectively, in the combined dataset from the two phases. An antagonistic interaction (rs1316298-smoking) and a synergetic interaction (rs4589502-smoking) were observed. The two interactions identified in our study may help explain some of the missing heritability in lung cancer susceptibility and present strong evidence for further study of these gene-smoking interactions, which are benefit to intensive screening and smoking cessation interventions.

Smoking and hOGG1 Ser326Cys polymorphism contribute to lung cancer risk: evidence from a meta-analysis

The human 8-oxoguanine DNA glycosylase (hOGG1) gene plays an important role in the repair of oxidatively damaged DNA base lesions and its functional single nucleotide polymorphisms (SNPs) may alter DNA repair capacity and thus contributes to cancer susceptibility. Numerous studies have investigated the association between hOGG1 Ser326Cys polymorphism and lung cancer susceptibility; however, the conclusions are still inconclusive. We searched eligible publications from MEDLINE, EMBASE, and CBM and performed a meta-analysis to assess the associations between hOGG1 Ser326Cys polymorphism and lung cancer risk. Pooled odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated to estimate risk associations, and false-positive report probability (FPRP) analysis was also carried out to evaluate significant findings. A total of 31 investigations with 10,220 cases and 12,284 controls were identified. When all studies were pooled, a significantly increased overall lung cancer risk was found (Cys/Cys vs. Ser/Ser: OR = 1.24, 95 % CI = 1.05-1.47, P = 0.013; recessive model: OR = 1.22, 95 % CI = 1.05-1.41, P = 0.008, and Cys vs. Ser: OR = 1.11, 95 % CI = 1.02-1.21, P = 0.022), and further stratification analysis showed that the association was stronger in Asians, never smokers, and more-cigarette takers. These results were confirmed by FPRP analysis. Despite some limitations, this meta-analysis provides solid evidence that hOGG1 Ser326Cys polymorphism may contribute to lung cancer risk, particularly for Asian populations, never smokers, and more-cigarette takers. Nevertheless, these findings warrant further validation in single large investigations.

The association between TP53 Arg72Pro polymorphism and lung cancer susceptibility: evidence from 30,038 subjects

BACKGROUND

The TP53 codon 72 polymorphism has been associated with the individual susceptibility to lung cancer. However, the association remains uncertain and varies with ethnicity, smoking status, cancer histology, and stage.

METHODS

We performed a meta-analysis to evaluate the relationship between TP53 Arg72Pro polymorphism and lung cancer susceptibility basing on 15,647 lung cancer patients and 14,391 controls from 36 published literatures. We also performed stratified analysis in populations of different ethnicities, smoking statuses, lung cancer stages, and histological types.

RESULTS

The analysis showed a significantly increased lung cancer susceptibility among Pro allele carriers (P < 0.001, odds ratio (OR) = 1.14, 95% confidence interval (CI) = 1.1-1.19), especially for smokers (P < 0.001, OR = 1.29, 95% CI = 1.12-1.47). Stratified analysis indicated that Pro72 elevates lung cancer susceptibility in Asians, while it has no effect on lung cancer risk of Caucasians. Moreover, Pro carriers present an increased risk of developing squamous cell carcinoma and adenocarcinoma, instead of large cell carcinoma and small cell carcinoma. Interestingly, patients with the Pro allele seemed to be diagnosed with lung cancer at the early stages (stage I-II, P = 0.008, OR = 1.2, 95% CI = 1.05-1.37).

CONCLUSIONS

Our results suggest that the Pro allele acts as a risk factor for development of lung cancer, especially for smokers and Asians.

Association between the NBS1 Glu185Gln polymorphism and lung cancer risk: a systemic review and meta-analysis

Nijmegen Breakage Syndrome protein 1 (NBS1) is one of the most important DNA repair proteins playing important roles in maintaining the genomic stability of NDA. Previous studies regarding the association between NBS1 8360G>C (Glu185Gln) polymorphism and lung cancer reported conflicting results. To derive a more precise estimation of this association, a systemic review and meta-analysis was performed. We performed a meta-analysis using eligible case-control studies to summarize the data on the association between the NBS1 Glu185Gln polymorphism and lung cancer risk. Odds ratios (ORs) with corresponding 95 % confidence intervals (95 %CIs) were pooled to assess the association between NBS1 Glu185Gln polymorphism and lung cancer risk. Six case-control studies with a total of 2,348 lung cancer cases and 2,401 controls without canner were included into the meta-analysis. Overall, there was an association between NBS1 Glu185Gln polymorphism and lung cancer risk under the dominant comparison model (fixed-effects OR GluGln/GlnGln vs. GluGlu = 1.21, 95 % CI 1.07-1.37, P = 0.002, I (2) = 8.1 %). Subgroup analysis by race suggested a significant association between NBS1 Glu185Gln polymorphism and lung cancer risk in Asians (fixed-effects OR GluGlnGlnGln vs. GluGlu = 1.22, 95 % CI 1.06-1.41, P = 0.005) but not in Caucasians (fixed-effects OR GluGlnGlnGln vs. GluGlu = 1.17, 95 % CI 0.91-1.50, P = 0.220). This meta-analysis supports that there is an association between NBS1 Glu185Gln polymorphism and lung cancer risk. More studies are needed to further verify this association.