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This case-control study aimed to investigate the association between PHLDB1 rs498872 polymorphism and the risk of glioma in a Chinese Han population. A total of 210 patients and 235 controls were enrolled in this study. The CT genotype and TT genotype were significantly associated with the risk of glioma (OR=1.48, 95%CI 1.00-2.19, P=0.05 and OR=2.40, 95%CI 1.06-4.10, P=0.03), respectively. In addition, T allele of PHLDB1 rs498872 polymorphism was significantly associated with an increased risk of glioma (OR=1.58, 95%CI 1.08-2.29, P=0.02). We also found that PHLDB1 rs498872 polymorphism was not associated with histology and tumor grade of glioma. In conclusion, this study found that PHLDB1 rs498872 polymorphism was significantly associated with glioma risk in Chinese Han population.

We conducted a study in a Chinese Han population to investigate the role of XRCC1 gene polymorphisms (Arg399Gln and Arg194Trp) with a risk of susceptibility to gliomas. Samples from 115 patients with gliomas and 228 control subjects were consecutively collected between March 2012 and December 2014. Genotype analysis of XRCC1 Arg399Gln and Arg194Trp was performed using polymerase chain reaction-restriction fragment length polymorphism assay. All the analyses were performed using the SPSS 17.0 software package. We observed that the XRCC1 Arg399Gln and Arg194Trp genotype frequencies conformed to the Hardy-Weinberg equilibrium. We observed that the Trp/Trp genotype of XRCC1 Arg194Trp was associated with an increased risk of glioma when compared to the wild-type genotype (odds ratio (OR) = 2.14, 95% confidence interval (CI) = 1.14-3.86, P = 0.03). In the dominant model, we found that the Arg/Trp + Trp/Trp genotype of XRCC1 Arg194Trp could significantly elevate the susceptibility of developing glioma (OR = 1.79, 95%CI = 1.07-0.94). However, we observed that the XRCC1 Arg399Gln genetic polymorphism did not influence the risk of glioma. In summary, we suggest that the XRCC1 Arg194Trp genetic polymorphism could be a predictive biomarker for the susceptibility to glioma in a Chinese population., Competing Interests: The authors declare no conflict of interest.

In this study, we assessed the association between the EFEMP1 rs3791679 polymorphism and glioma risk in a Chinese Han population. A total of 94 glioma patients and 206 healthy controls who conformed to the inclusion and exclusion criteria were recruited from Baogang Hospital between March 2012 and October 2014. The EFEMP1 rs3791679 gene polymorphism was assessed using a polymerase chain reaction-restriction fragment length polymorphism assay and the results were statistically analyzed using SPSS Statistics 17.0. The results of unconditional logistic regression analysis revealed that the GG genotype of EFEMP1 rs3791679 was positively correlated with increased susceptibility to glioma (adjusted OR = 2.09, 95%CI = 1.21-7.81). Moreover, the GG genotype of EFEMP1 rs3791679 was correlated with higher risk of glioma compared to the AA+GA genotype (OR = 2.60, 95%CI = 1.08-6.28) in the regressive model. In conclusion, we report that the EFEMP1 rs3791679 polymorphism influences glioma susceptibility in the Chinese Han population., Competing Interests: The authors declare no conflict of interest.

So far, epidemiological studies have been performed to investigate the association of CDKN2A/B rs4977756 polymorphism and glioma risk. However, the results from different studies remain inconsistent. To clarify these conflicts and to quantitatively evaluate the effect of rs4977756 polymorphism on glioma risk, a meta-analysis was conducted using relevant published clinical studies about rs4977756 polymorphisms and glioma risk. Relevant studies concerning the association between rs4977756 polymorphism and risk of glioma were included in this meta-analysis. Odds ratio (OR) and 95 % confidence interval (CI) were calculated under fixed or random effects models when appropriate. Subgroup analyses were performed by race. This meta-analysis included 13 studies with a total of 8129 cases and 15,858 controls. The pooled results showed that there was an obvious association of CDKN2A/B rs4977756 polymorphism with risk of glioma in all four comparison models (dominant model/AG + GG vs. AA: OR = 1.36, 95 %CI = 1.20-1.54, p < 0.01; heterozygote comparison/AG vs. AA: OR = 1.31, 95 %CI = 1.12-1.53, p < 0.01; homozygote comparison/GG versus AA: OR = 1.49, 95 %CI = 1.36-1.64, p < 0.01; additive model/G vs. A: OR = 1.23, 95 %CI = 1.18-1.28, p < 0.01, respectively). For the subgroup analyses of ethnicities, similar results were observed in Caucasians. However, the association was not found between rs4977756 polymorphism and the risk of glioma in all models for the Asian studies. The CDKN2A/B rs4977756 polymorphism is obvious increase the risk of glioma in Caucasians. Future studies are needed to confirm the results in other ethnic populations.

The susceptibility to glioma is not well understood. It has been suggested that the X-ray cross complementing group 3 (XRCC3) gene influences the capacity to repair DNA damage, leading to increased glioma susceptibility. In this study, we evaluated the relationship between XRCC3 mutations and glioma risk. Genotypes were assessed in 389 Chinese glioma patients and 358 healthy controls. XRCC3 Thr241Met (rs861539) and 2 additional polymorphisms, rs3212112 (c.774+19T>G) and rs1799796 (c.562-14A>G), were directly sequenced. The frequency of the rs861539 T allele was significantly lower in the glioma group than in healthy controls [11.1 vs 17.7%, odds ratio = 0.62 (0.48-0.80), P < 0.001]; the frequencies of the CT or CT+TT genotypes differed between groups (18.5 vs 31%, 20.3 vs 33.2%, respectively). The frequency of the rs3212112 G allele was significantly higher in the glioma group than in healthy controls [15.8 vs 5.3%, odds ratio = 2.94 (2.07-4.17), P < 0.001]. The frequencies of the GT or TG+GG genotypes differed between groups (25.4 vs 7.8%, 28.5 vs 9.2%, respectively). This study demonstrates that the rs861539 and rs3212112 polymorphisms in the XRCC3 gene may influence the risk of glioma development in Chinese populations.

Numerous studies have investigated the risk of cancer associated with the polymorphism of epidermal growth factor (EGF) 61A>G, but results have been inconsistent. We performed this meta-analysis to drive a more precise estimation of the association between this polymorphism and risk of glioma. A comprehensive search was conducted to identify all case-control studies on the EGF +61A>G polymorphism and glioma risk. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to assess the strength of the association. Statistical analysis was performed with the software program Stata (version 12.0). A total of ten eligible studies, including 1,888 cases and 2,836 controls were included in this work. Overall, there was a significant association between EGF +61A>G polymorphism and glioma risk in the allele model (OR = 1.419, 95% CI = 1.144-1.759, P = 0.001). In the subgroup analysis by ethnicity, significant associations were also found in Asian populations under all different genetic models (homozygote model: OR = 1.727, 95% CI = 1.310-2.275, P = 0.000; heterozygote model: OR = 1.202, 95% CI = 1.023-1.413, P = 0.025; dominant model: OR = 1.279, 95% CI = 1.096-1.491, P = 0.002; recessive model: OR = 1.590, 95% CI = 1.221-2.070, P = 0.001; and A-allele versus G-allele OR = 1.600, 95% CI = 1.145-2.236, P = 0.006). However, no significant associations were found among Caucasians in all comparison models. In conclusion, the results suggest that there is a significant association between EGF +61A>G polymorphism and glioma risk among Asians.

Methylenetetrahydrofolate reductase (MTHFR) gene plays key roles not only in folate metabolism but also in carcinogenesis. The single nucleotide polymorphism MTHFR C677T has been indicated in the development of various tumors. The effect of the MTHFR C677T polymorphism on brain tumors remains poorly understood. We performed the present meta-analysis and aimed to provide a better understanding of the pathogenesis of brain tumors. A literature search of the PubMed, Embase, Web of Science, and Wanfang databases was carried out for potential relevant publications. We calculated the pooled odds ratio (OR) with corresponding 95% confidence interval (95% CI) to assess the association of MTHFR C677T with the susceptibility to brain tumors. We also performed stratified analysis and sensitivity analysis to further estimate the genetic association. All statistical analyses were conducted by the use of STATA 11.0 (STATA Corporation, College Station, TX, USA). Eight case-control studies involving a total of 3,059 cases and 3,324 controls were retrieved according to the inclusion criteria. The overall ORs suggested that the MTHFR C677T variant can exert a risk effect on brain tumor development under the following contrast models (OR(TC vs. CC) = 1.14, 95% CI 1.02-1.27, P OR = 0.018; OR(TT + TC vs. CC)= 1.23, 95% CI 1.01-1.51, P(OR) = 0.043). No significant correlation was identified among the Caucasians, but not among the Asians. In addition, the TC genotype carriers were more susceptible to meningioma when compared with the CC genotype carriers (OR(TC vs. CC) = 1.38, 95% CI 1.15-1.65, P(OR) < 0.001). The MTHFR C677T polymorphism seemed to exert no effect on glioma risk. The current meta-analysis firstly provides evidence that the MTHFR C677T polymorphism may modify the risk for brain tumors, particularly meningioma. The role of the MTHFR C677T variant in brain tumor pathogenesis across diverse ethnicities needs further elucidation by more future studies with large sample size.

Common variants of multiple genes play a role in glioma onset. However, research related to astrocytoma, the most common primary brain neoplasm, is rare. In this study, we chose 21 tagging SNPs (tSNPs), previously reported to be associated with glioma risk in a Chinese case-control study from Xi'an, China, and identified their contributions to astrocytoma susceptibility. We found an association with astrocytoma susceptibility for two tSNPs (rs6010620 and rs2853676) in two different genes: regulator of telomere elongation helicase 1 (RTEL1) and telomerase reverse transcriptase (TERT), respectively. We confirmed our results using recessive, dominant, and additive models. In the recessive model, we found two tSNPs (rs2297440 and rs6010620) associated with increased astrocytoma risk. In the dominant model, we found that rs2853676 was associated with increased astrocytoma risk. In the additive model, all three tSNPs (rs2297440, rs2853676, and rs6010620) were associated with increased astrocytoma risk. Our results demonstrate, for the first time, the potential roles of RTEL1 and TERT in astrocytoma development.

Glioblastoma multiform (GBM; World Health Organization (WHO) grade IV) and anaplastic astrocytomas (AA; WHO grade III) are highly aggressive and lethal astrocytic brain tumors. To detect cancer-specific somatic mutations in two hot-spot regions of PIK3CA gene, the helical and kinase domains (encoded by exons 9 and 20, respectively) in GBM and AA, the authors examined the respective sequences 31 paraffin-embedded samples (23 GBM and 8 AA). The samples were obtained from a group of Iranian patients affected with high-grade glioblastoma (HGG). The overall prevalence of PIK3CA mutations was 23% (7/31) for both tumor types (22% in GBM, and 25% in AA). Five mutations were detected in exon 20, p.Arg992Gln (c.2976G→A), p.Met1005Val (c.3014A→G), p.Ile1019→Val (c.3056A→G), p.Ser1008Cys (c.3024C→G), and p.Asn1044Asp (c.3130A→G), and one mutation in exon 9, p.Glu545Ala (c.1634A→C). Additionally exons 4-8 of P53 gene in four unrelated young patients, who showed no mutations in PIK3CA exons 9 and 20, were analyzed. Three mutations were identified: p.Pro72Ala (c.214C→G), g.11608G→T (homozygote splice mutation), and p.Thr170Thr (c.510G→A silent mutation). In conclusion, mutation detection in PIK3CA in patients with a high degree of malignancy and early age at diagnosis should be included in molecular diagnostic protocols, also with regard to possible upcoming therapies.