Multi-index comprehensive evaluation of the efficacy and response mechanism of immunotherapy in non-small cell lung cancer

OBJECTIVE

This research conducted multi-index comprehensive evaluations of the immunotherapeutic efficacy and response in non-small cell lung cancer (NSCLC).

METHODS

Forty-five patients with epidermal growth factor receptor (EGFR)/anaplastic lymphoma kinase (ALK) wild-type advanced NSCLC who received immunotherapy were included. Immunohistochemistry was adopted to detect the expression levels of programmed death ligand 1 (PD-L1) with X-ray cross-complementing protein 1 (XRCC1) and excision repair cross-complementing group 1 (ERCC1) proteins in tumor tissues. Flow cytometry was utilized to measure the levels of T-cell subsets in peripheral blood before and after treatment. PCR-RELP method was employed to evaluate XRCC1 and ERCC1 gene polymorphisms in peripheral blood. According to the treatment effect, patients evaluated as complete response (CR), partial response (PR), and stable disease (SD) were categorized into the immune response group, and patients evaluated as progressive disease (PD) were categorized into the immune unresponsive group. The correlation between PD-L1 protein expression, XRCC1 and ERCC1 protein expression, gene polymorphisms, T-cell subpopulation levels, and treatment efficacy was analyzed.

RESULTS

The therapeutic efficacy of patients with positive PD-L1 expression was better than that of patients with negative PD-L1 expression (P < 0.05). After treatment, peripheral blood CD3+ and CD4+ cell levels and Thl/Th2 cell levels were higher and CD8+ T cells were lower in the immune response group than in the immune unresponsive group (P < 0.05). Among the patients in the immune response group, peripheral blood CD3+ and CD4+ cell levels were higher and CD8+ T cells were lower in patients with positive PD-L1 expression than in patients with negative PD-L1 expression (P < 0.05). In the XRCC1 gene, the proportion of patients in the immune response group carrying the Arg/Trp + Trp/Trp genotype was higher than that of patients in the immune unresponsive group (P < 0.05). In the ERCC1 gene, the proportion of patients in the immune response group carrying the C/T + T/T genotype was higher than that of patients in the immune unresponsive group (P < 0.05). The positive expression rates of XRCC1 and ERCC1 in patients in the immune unresponsive group were higher than those in the immune response group (P < 0.05).

CONCLUSION

PD-L1 protein expression, XRCC1 and ERCC1 protein expression, and gene polymorphisms are associated with immunotherapy outcome in EGFR/ALK wild-type advanced NSCLC patients, and may be biological indicators for predicting immunotherapy outcome in EGFR/ALK wild-type advanced NSCLC patients.

PARP1 rs1136410 Val762Ala contributes to an increased risk of overall cancer in the East Asian population: a meta-analysis

Objectives

To investigate the association between poly(ADP-ribose) polymerase 1 (PARP1) rs1136410 Val762Ala and cancer risk in Asian populations, as published findings remain controversial.

Methods

The PubMed and EMBASE databases were searched, and references of identified studies and reviews were screened, to find relevant studies. Meta-analyses were performed to evaluate the association between PARP1 rs1136410 Val762Ala and cancer risk, reported as odds ratio (OR) and 95% confidence interval (CI).

Results

A total of 24 studies with 8 926 cases and 15 295 controls were included. Overall, a significant association was found between PARP1 rs1136410 Val762Ala and cancer risk in East Asians (homozygous: OR 1.19, 95% CI 1.06, 1.35; heterozygous: OR 1.10, 95% CI 1.04, 1.17; recessive: OR 1.13, 95% CI 1.02, 1.25; dominant: OR 1.13, 95% CI 1.06, 1.19; and allele comparison: OR 1.09, 95% CI 1.03, 1.15). Stratification analyses by race and cancer type revealed similar results for gastric cancer among the Chinese population.

Conclusion

The findings suggest that PARP1 rs1136410 Val762Ala may be significantly associated with an increased cancer risk in Asians, particularly the Chinese population.

Association of XRCC1, XRCC2 and XRCC3 Gene Polymorphism with Esophageal Cancer Risk

Aim

The X-ray repair cross-complementing (XRCC) gene polymorphisms influence esophageal carcinogenesis by altering the DNA repair capacity. The present study was designed to screen five single nucleotide polymorphisms (SNPs) of XRCC genes for their susceptibility to esophageal cancer (EC) risk. There is no previous report on these polymorphisms for EC from India, where EC frequency is high.

Methods

The present study included 497 subjects (213 EC patients and 284 healthy controls). The polymorphisms were screened using the PCR-RFLP method and allele and genotype distribution were compared using chi-square test. Association analysis was done by haplotype analysis and linkage disequilibrium (LD) analysis. Gene–gene interactions were identified using multifactor dimensionality reduction (MDR). The risk was calculated using binary logistic regression.

Results

For XRCC1 p.Arg399Gln, a decreased risk for EC was associated with the AA genotype [OR (95% CI): 0.53 (0.3–0.95), p=0.03] even after adjusting for various covariates [OR (95% CI): 0.49 (0.26–0.9), p=0.024] and with the recessive model [OR (95% CI): 0.49 (0.27–0.8), p=0.016]. The GA genotype of p.Arg280His was associated with an increased risk for EC [OR (95% CI): 1.7 (1.0–2.82), p= 0.045] after adjustments. The two XRCC1 polymorphisms, p.Arg399Gln and p.Arg194Trp were in slight LD among EC patients (D̍́=0.845, r²=0.042). XRCC2 and XRCC3 polymorphisms were not associated with EC risk.

Conclusion

XRCC1 p.Arg399Gln plays a protective role in the development of the EC. The study is the first report from India, providing baseline data about genetic polymorphisms in DNA repair genes XRCC1, XRCC2 and XRCC3 modulating overall EC risk.

Interaction among susceptibility genotypes of PARP1 SNPs in thyroid carcinoma

Polymorphisms in DNA repair genes may alter the repair mechanism which makes the person susceptible to DNA damage. Polymorphic variants in these DNA repair pathway genes such as Poly (ADP-ribose) polymerase- 1 (PARP1) have been associated with susceptibility of several types of cancer including thyroid. Many studies have been published on PARP1 gene polymorphisms and carcinogenesis with inconsistent results. The present study was designed to explore the link between the PARP1 polymorphisms and thyroid cancer risk. This case-control study was comprised of 456 thyroid cancer patients and 400 healthy controls. Three SNPs of PARP1 gene; rs1136410, rs1805414 and rs1805404 were analyzed using ARMS-PCR. The combined genotype and haplotype analysis were performed using haploview software 4.2. Major allele homozygote (CC) of rs1136410 and combined genotype (TT+TC) of rs180414 showed a significant association with thyroid cancer risk (OR = 1.30; 95% CI 0.99–1.77; P = 0.05) and (OR = 0.43; 95% CI = 0.27–0.67; P = 0.03). Histological subtype analysis showed the significant association of selected PARP1 SNPs with papillary, follicular and anaplastic subtypes in thyroid cancer patients. Haplotype analysis showed that TCT (p = 0.01), CTT (p = 0.02) and CTC (p = 0.03) were significantly higher in controls when compared to cases. However, TTC (p = 0.05) and TCC (p = 0.01) haplotype frequency was significantly higher in cases compared to controls. Global haplotype analysis showed that there was an overall significant difference between cases and controls (p = 0.001). Identification of these genetic risk markers may provide evidence for exploring insight into mechanisms of pathogenesis and subsequently aid in developing novel therapeutic strategies for thyroid cancer.

TGFβ C-509T, TGFβ T869C, XRCC1 Arg194Trp, IKBα C642T, IL4 C-590T Genetic polymorphisms combined with socio-economic, lifestyle, diet factors and gastric cancer risk: A case control study in South Indian population

BACKGROUND

Gastric cancer is worldwide the third major cause of cancer related death. Risk factors for gastric cancer includes Helicobacter pylori infection, gastric ulcer, less hygienic condition, use of tobacco, alcohol consumption, use of salted, smoked food, genetic alterations etc. In order to identify the risk factors associated with gastric cancer in South Indian population a case-control study involving 200 proven gastric cancer cases and 400 controls was conducted.

METHODS

A structured questionnaire was used to interview all the subjects who participated in our study. Genotyping assay was performed using Taqman allelic discrimination assay for 5 Single Nucleotide Polymorphisms (SNPs)-TGFβ C-509T, TGFβ T869C, XRCC1 Arg194Trp, IkBα C642T and IL4C-590T.

RESULTS

Odds Ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression. Statistical analysis on socio-economic factors, lifestyle factors had showed that subjects from low socio economic status, use of tobacco and consumption of non-vegetarian food had increased risk of developing gastric cancer. Multi-factorial analysis for the SNPs adjusting for the risk factors obtained in this study showed that TGFΒ C-509T TT genotypes had four fold increased risk of gastric cancer (OR = 4.11, CI = 1.02-16.56) and TGFβ T869C CC genotype had a decreased risk of gastric cancer (OR = 0.21, CI = 0.05-0.85).

CONCLUSION

Economic status, tobacco use and food habits play a significant role in gastric cancer development. TT genotype for TGFβ C-509T had an increased risk and CC genotype for TGFβ T869C had a decreased risk of gastric cancer in south Indian population after adjusting for socio-economic factors and lifestyle factors.

Variant Alleles in XRCC1 Arg194Trp and Arg399Gln Polymorphisms Increase Risk of Gastrointestinal Cancer in Sabah, North Borneo

BACKGROUND

The XRCC1 protein facilitates various DNA repair pathways; single-nucleotide polymorphisms (SNPs) in this gene are associated with a risk of gastrointestinal cancer (GIC) with inconsistent results, but no data have been previously reported for the Sabah, North Borneo, population. We accordingly investigated the XRCC1 Arg194Trp and Arg399Gln SNPs in terms of GIC risk in Sabah.

MATERIALS AND METHODS

We performed genotyping for both SNPs for 250 GIC patients and 572 healthy volunteers using a polymerase chain reaction- restriction fragment length polymorphism approach. We validated heterozygosity and homozygosity for both SNPs using direct sequencing.

RESULTS

The presence of a variant 194Trp allele in the Arg194Trp SNP was significantly associated with a higher risk of GIC, especially with gastric and colorectal cancers. We additionally found that the variant 399Gln allele in Arg399Gln SNP was associated with a greater risk of developing gastric cancer. Our combined analysis revealed that inheritance of variant alleles in both SNPs increased the GIC risk in Sabah population. Based on our etiological analysis, we found that subjects ≥50 years and males who carrying the variant 194Trp allele, and Bajau subjects carrying the 399Gln allele had a significantly increased risk of GIC.

CONCLUSIONS

Our findings suggest that inheritance of variant alleles in XRCC1 Arg194Trp and Arg399Gln SNPs may act as biomarkers for the early detection of GIC, especially for gastric and colorectal cancers in the Sabah population.

Interaction between Helicobacter pylori and host genetic variants in gastric carcinogenesis

Helicobacter pylori (H. pylori) is the definite carcinogen of gastric cancer. H. pylori infection induces chronic inflammation, causes DNA damage and aberrant methylation of genes and these pathways are involved in H. pylori-related gastric carcinogenesis. Polymorphisms of the genes involved in these pathways could alter susceptibility to gastric cancer. In this mini review, we focused on the role of polymorphisms in these genes on the susceptibility to gastric cancer, with a particular emphasis on their possible interactions with H. pylori infection. We found that many studies on this theme did not simultaneously report H. pylori infection and the interactions remained inconclusive.

Association of DNA repair and xenobiotic pathway gene polymorphisms with genetic susceptibility to gastric cancer patients in West Bengal, India

Gastric cancer is one of the most common malignancies in India. DNA repair gene or xenobiotic pathway gene polymorphisms have recently been shown to affect individual susceptibility to gastric cancer. Here, the possible interaction between common polymorphisms in X-ray repair cross complementing group I (XRCC1) gene and glutathione S-transferase (GST) genes (GSTM1, GSTT1 and GSTP1), smoking and alcohol consumption and overall survival in gastric cancer patients were evaluated. In this population-based case control study, 70 gastric cancer patients and 82 healthy controls were enrolled. The epidemiological data were collected by a standard questionnaire, and blood samples were collected from each individual. XRCC1 Arg194Trp, Arg280His and Arg399Gln polymorphisms were determined by polymerase chain reaction and direct DNA sequencing. GSTM1 and GSTT1 null polymorphisms and GSTP1 Ile105Val polymorphism were identified by multiplex polymerase chain reaction and restriction fragment length polymorphism (RFLP), respectively. The risk of gastric cancer was significantly elevated in individuals with XRCC1 Arg/Gln +Gln/Gln (p = 0.031; odds ratio = 2.32; 95 % confidence interval (CI) 1.07-5.06) and GSTP1 Val/Val genotype (p = 0.009; odds ratio = 8.64; 95 % CI 1.84-40.55). An elevated risk for GC was observed in smokers and alcohol consumers carrying GSTP1 Ile/Val +Val/Val genotype (p = 0.041; odds ratio = 3.71; 95 % CI 0.98-14.12; p = 0.002; odds ratio = 12.31; 95 % CI 1.71-88.59). These findings suggest that XRCC1 rs25487 and GSTP1 rs1695 can be considered as a risk factor associated with gastric cancer and might be used as a molecular marker for evaluating the susceptibility of the disease.

Polymorphisms of PRLHR and HSPA12A and risk of gastric and colorectal cancer in the Chinese Han population

Background

Gastric and colorectal cancers have a major impact on public health, and are the most common malignant tumors in China. The aim of this research was to study whether polymorphisms of CHCHD3P1-HSP90AB7P, GRID1, HSPA12A, PRLHR, SBF2, POLD3 and C11orf93-C11orf92 genes are associated with the risk of gastric and colorectal cancers in the Chinese Han population.

Methods

We genotyped seven single nucleotide polymorphisms (SNPs) from seven genes. We selected 588 patients with gastric cancer and 449 with colorectal cancer, along with 703 healthy controls. All these SNPs were evaluated using the χ2 test and genetic model analysis.

Results

The genotype “A/T” of rs12413624 in PRLHR gene was associated with a decreased risk of colorectal cancer in allele model analysis [odds ratio (OR) = 0.81; 95 % confidence interval (CI) = 0.68–0.97; p = 0.018] and log-additive model analysis (OR = 0.81; 95 % CI = 0.66–0.98; p = 0.032). The genotype “A/G” of rs1665650 in HSPA12A gene was associated with a decreased risk of gastric cancer in overdominant model analysis (OR = 0.77; 95 % CI = 0.60–0.99; p = 0.038).

Conclusions

Our results provide evidence that variants of PRLHR gene are a protective factor in colorectal cancer and variants of HSPA12A gene are a protective factor in gastric cancer in the Chinese Han population.

The role of base excision repair in the development of primary open angle glaucoma in the Polish population

Glaucoma is a leading cause of irreversible blindness in developing countries. Previous data have shown that progressive loss of human TM cells may be connected with chronic exposure to oxidative stress. This hypothesis may suggest a role of the base excision repair (BER) pathway of oxidative DNA damage in primary open angle glaucoma (POAG) patients. The aim of our study was to evaluate an association of BER gene polymorphism with a risk of POAG. Moreover, an association of clinical parameters was examined including cup disk ratio (c/d), rim area (RA) and retinal nerve fiber layer (RNFL) with glaucoma progression according to BER gene polymorphisms. Our research included 412 patients with POAG and 454 healthy controls. Gene polymorphisms were analyzed by PCR-RFLP. Heidelberg Retinal Tomography (HRT) clinical parameters were also analyzed. The 399 Arg/Gln genotype of the XRCC1 gene (OR 1.38; 95% CI 1.02-1.89 p = 0.03) was associated with an increased risk of POAG occurrence. It was indicated that the 399 Gln/Gln XRCC1 genotype might increase the risk of POAG progression according to the c/d ratio (OR 1.67; 95% CI 1.07-2.61 P = 0.02) clinical parameter. Moreover, the association of VF factor with 148 Asp/Glu of APE1 genotype distribution and POAG progression (OR 2.25; 95% CI 1.30-3.89) was also found. Additionally, the analysis of the 324 Gln/His MUTYH polymorphism gene distribution in the patient group according to RNFL factor showed that it might decrease the progression of POAG (OR 0.47; 95% CI 0.30-0.82 P = 0.005). We suggest that the 399 Arg/Gln polymorphism of the XRCC1 gene may serve as a predictive risk factor of POAG.

Association between the XRCC1 Arg194Trp polymorphism and risk of cancer: evidence from 201 case-control studies

The Arg194Trp polymorphism in the X-ray cross-complementing group 1 (XRCC1) had been implicated in cancer susceptibility. The previous published data on the association between XRCC1 Arg194Trp polymorphism and cancer risk remained controversial. Hence, we performed a meta-analysis to investigate the association between cancer susceptibility and XRCC1 Arg194Trp (59,227 cases and 81,587 controls from 201 studies) polymorphism in different inheritance models. We used odds ratios with 95 % confidence intervals to assess the strength of the association. Overall, significantly increased cancer risk was found (recessive model: (odds ration [OR] = 1.18, 95% confidence interval [CI] = 1.09-1.27; homozygous model: OR = 1.21, 95% CI = 1.10-1.33; additive model: OR = 1.05, 95% CI = 1.01-1.09) when all eligible studies were pooled into the meta-analysis. In further stratified and sensitivity analyses, significantly increased glioma risk was found among Asians, significantly decreased lung cancer risk was found among Caucasians, and significant increased breast cancer risk was found among hospital-based studies. In summary, this meta-analysis suggests that Arg194Trp polymorphism may be associated with increased breast cancer risk, Arg194Trp polymorphism is associated with increased glioma risk among Asians, and Arg194Trp polymorphism is associated with decreased lung cancer risk among Caucasians. In addition, our work also points out the importance of new studies for Arg194Trp association in some cancer types, such as gastric, pancreatic, prostate, and nasopharyngeal cancers, where at least some of the covariates responsible for heterogeneity could be controlled, to obtain a more conclusive understanding about the function of the XRCC1 Arg194Trp polymorphism in cancer development (I (2) > 75%).

PARP-1 Val762Ala polymorphism and risk of cancer: a meta-analysis based on 39 case-control studies

Background

Poly(ADP-ribose) polymerase-1 (PARP-1) is a nuclear chromatin-associated enzyme involved in several important cellular processes, particularly in the DNA repair system. PARP-1 rs1136410: C>T is among the most studied polymorphisms and likely involved in human carcinogenesis. However, results from previous studies are inconclusive. Thus, a meta-analysis was conducted to derive a more precise estimation of the effects of this enzyme.

Methodology and Principal Findings

A comprehensive search was conducted in the PubMed and EMBASE databases until December 9, 2013. A total of 39 studies with 16,783 cancer cases and 23,063 control subjects were included in the meta-analysis on the basis of the inclusion and exclusion criteria. No significant association between the PARP-1 Val762Ala polymorphism and cancer risk was found when all of the studies were pooled into the analysis (VA + AA vs. VV: OR = 1.03, 95% CI = 0.95–1.11). The subgroup analysis of cancer types revealed that the –762Ala allele was associated with increased risk of gastric, cervical, and lung cancers and a decreased risk of glioma. In addition, a significantly increased risk of cancer associated with the polymorphism was observed in Asian descendents (VA + AA vs. VV: OR = 1.17, 95% CI = 1.09–1.25; AA vs. VV: OR = 1.28, 95% CI = 1.08–1.51; VA vs. VV: OR = 1.12, 95% CI = 1.04–1.20; AA vs. VA + VV: OR = 1.09, 95% CI = 1.03–1.39). These results also indicated that a joint effect between PARP-1 Val762Ala and XRCC1 Arg399Gln could be involved in the risk of cancer development (OR = 3.53, 95% CI = 1.30–9.59).

Conclusion

The present meta-analysis provides evidence that the PARP-1 Val762Ala may be involved in cancer development at least in some ethnic groups (Asian) or some specific cancer types (gastric, cervical, and lung cancers, and glioma).

Association of XRCC1 gene polymorphisms with susceptibility to gastric cancer in Chinese Han population

OBJECTIVES

Gastric cancer is one of the most frequently causing cancer-related deaths worldwide. The X-ray repair complementing group 1 gene (XRCC1) is an important candidate gene for influencing gastric cancer risk. This study aimed to evaluate the associations between XRCC1 genetic variants and gastric cancer susceptibility in Chinese Han population.

METHODS

Four hundred twenty-four gastric cancer patients and 430 cancer-free controls were enrolled. Two genetic variants (c.1254C>T and c.1779C>G) of XRCC1 gene were genotyped by created restriction site-polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism methods, respectively.

KEY FINDINGS

Results from this study indicated that the allele and genotype frequencies of these two genetic variants were statistically different between gastric cancer patients and cancer-free controls. The association analyses suggested that these two genetic variants were statistically associated with the increased risk of gastric cancer (for c.1254C>T, T versus C: odds ratio (OR) = 1.44, 95% confidence interval (CI) 1.17-1.77; for c.1779C>G, G versus C: OR = 1.51, 95% CI 1.22-1.86). The allele-T of c.1254C>T and allele-G c.1779C>G genetic variants may contribute to the susceptibility to gastric cancer in Chinese Han population.

CONCLUSION

Our data suggest that these two genetic variants might be used as molecular markers for evaluating the susceptibility to gastric cancer.

Association between the PARP1 Val762Ala polymorphism and cancer risk: evidence from 43 studies

BACKGROUND

Poly (ADP-ribose) polymerase-1 (PARP-1) plays critical roles in the detection and repair of damaged DNA, as well as cell proliferation and death. Numerous studies have examined the associations between PARP1 Val762Ala (rs1136410 T>C) polymorphism and cancer susceptibility; nevertheless, the findings from different research groups remain controversial.

METHODS

We searched literatures from MEDLINE, EMBASE and CBM pertaining to such associations, and then calculated pooled odds ratio (OR) and 95% confidence interval (CI) by using random-effects model. The false-positive report probability (FPRP) analysis was used to confirm the validity of significant findings. Moreover, potential effects of rs1136410 variants on PARP1 mRNA expression were analyzed for three ethnicities by combining data from HapMap (genotype) and SNPexp (mRNA expression).

RESULTS

The final meta-analysis incorporated 43 studies, consisting of 17,351 cases and 22,401 controls. Overall, our results did not suggest significant associations between Ala variant (Ala/Ala or Ala/Val genotype) and cancer risk. However, further stratification analysis showed significantly increased risk for gastric cancer (Ala/Ala vs. Val/Val: OR = 1.56, 95% CI = 1.01-2.42, Ala/Val vs. Val/Val: OR = 1.34, 95% CI = 1.14-1.58, dominant model: OR = 1.41, 95% CI = 1.21-1.65 and Ala vs. Val: OR = 1.29, 95% CI = 1.07-1.55). On the contrary, decreased risk for brain tumor (Ala/Val vs. Val/Val: OR = 0.77, 95% CI = 0.68-0.87, dominant model: OR = 0.77, 95% CI = 0.68-0.87 and Ala vs. Val: OR = 0.82, 95% CI = 0.74-0.91). Additionally, we found that the Ala carriers had a significantly increased risk in all models for Asians. Our mRNA expression data provided further biological evidence to consolidate this finding.

CONCLUSIONS

Despite some limitations, this meta-analysis found evidence for an association between the PAPR1 Val762Ala and cancer susceptibility within gastric cancer, brain tumor and Asian subgroups.

Two DNA repair gene polymorphisms on the risk of gastrointestinal cancers: a meta-analysis

PARP-1 and MGMT play an important role in the DNA repair system and therefore have been implicated in human carcinogenesis. However, the association between the most studied PARP-1 rs1136410: T > C and MGMT rs12917: C > T polymorphism and risk of gastrointestinal (GI) cancers was reported with inconclusive results. Accordingly, a meta-analysis of 23 published case-control studies was conducted to assess the strength of association using crude odds ratios (ORs) with 95% confidence intervals (CIs). Overall, the C allele of PARP-1 rs1136410: T > C polymorphism was significantly associated with increased susceptibility of GI cancers (homozygote comparison: OR = 1.43, 95% CI 1.14-1.81; heterozygote comparison: OR = 1.18, 95% CI 1.07-1.29; dominant model: OR = 1.23, 95% CI 1.12-1.35; recessive model: OR = 1.30, 95% CI 1.04-1.62; allelic comparison: OR = 1.19, 95% CI 1.07-1.32). In the subgroup analysis, still obvious associations were found in the Asian population, gastric cancer, and high-quality studies. For MGMT rs12917: C > T polymorphism, no obvious associations were found for all genetic models overall. However, in the subgroup analysis, we found that the T allele was significantly associated with reduced colorectal cancer risk for heterozygote (OR = 0.83, 95% CI 0.70-0.97) and dominant model (OR = 0.84, 95% CI 0.72-0.98). In conclusion, this meta-analysis suggests that the PARP-1 rs1136410: T > C polymorphism is a susceptibility factor for GI cancers, but the variant allele of MGMT rs12917: C > T polymorphism appears to be a protective factor for colorectal cancer. Large-scale and well-designed case-control studies are necessary to validate the risk identified in the present meta-analysis.

Comprehensive study on associations between nine SNPs and glioma risk

AIM

Glioma cancer is the most common type of adult brain tumor. Recent genome-wide association studies (GWAS) have identified various new susceptibility regions and here we conducted an extensive analysis of associations between 12 single nucleotide polymorphisms (SNPs) and glioma risk.

METHODS

A total of 197 glioma cases and 197 health controls were selected, and 9 SNPs in 8 genes were analyzed using the Sequenom MassARRAY platform and Sequenom Assay Design 3.1 software.

RESULTS

We found the MAF among selected controls were consistent with the MAF from the NCBI SNP database. Among 9 SNPs in 8 genes, we identified four significant SNP genotypes associated with the risk of glioma, C/C genotype at rs730437 and T/T genotype at rs1468727 in ERGF were protective against glioma, whereas the T/T genotype at rs1799782 in XRCC1 and C/C genotype at rs861539 in XRCC3 conferred elevated risk.

CONCLUSION

Our comprehensive analysis of nine SNPs in eight genes suggests that the rs730437 and rs1468727 in ERGF, rs1799782 in XRCC1 gene, and rs861539 in XRCC3 gene are associated with glioma risk. These findings indicate that genetic variants of various genes play a complex role in the development of glioma.