Glioma Susceptibility Research Articles

Genetic variants in MIR17HG affect the susceptibility and prognosis of glioma in a Chinese Han population

BackgroundlncRNA MIR17HG was upregulated in glioma, and participated in promoting proliferation, migration and invasion of glioma. However, the role of MIR17HG polymorphisms in the occurrence and prognosis of glioma is still unclear.MethodsIn the study, 592 glioma patients and 502 control subjects were recruited. Agena MassARRAY platform was used to detect the genotype of MIR17HG polymorphisms. Logistic regression analysis was used to evaluate the relationship between MIR17HG single nucleotide polymorphisms (SNPs) and glioma risk by odds ratio (OR) and 95% confidence intervals (CIs). Kaplan–Meier curves, Cox hazards models were performed for assessing the role of these SNPs in glioma prognosis by hazard ratios (HR) and 95% CIs.ResultsWe found that rs7318578 (OR = 2.25, p = 3.18 × 10− 5) was significantly associated with glioma susceptibility in the overall participants. In the subgroup with age < 40 years, rs17735387 (OR = 1.53, p = 9.05 × 10− 3) and rs7336610 (OR = 1.35, p = 0.016) were related to the higher glioma susceptibility. More importantly, rs17735387 (HR = 0.82, log-rank p = 0.026) were associated with the longer survival of glioma patients. The GA genotype of rs17735387 had a better overall survival (HR = 0.75, log-rank p = 0.013) and progression free survival (HR = 0.73, log-rank p = 0.032) in patients with I-II glioma. We also found that rs72640334 was related to the poor prognosis (HR = 1.49, Log-rank p = 0.035) in female patients. In the subgroup of patients with age ≥ 40 years, rs17735387 was associated with a better prognosis (HR = 0.036, Log-rank p = 0.002).ConclusionOur study firstly reported that MIR17HG rs7318578 was a risk factor for glioma susceptibility and rs17735387 was associated with the longer survival of glioma among Chinese Han population, which might help to enhance the understanding of MIR17HG gene in gliomagenesis. In subsequent studies, we will continue to collect samples and follow up to further validate our findings and further explore the function of these MIR17HG SNPs in glioma in a larger sample size.

The genetic polymorphisms of angiotensin converting enzyme insertion/deletion and glioma susceptibility: A meta-analysis.

Objective:The previous studies on angiotensin converting enzyme (ACE) insertion/deletion (I/D) genetic polymorphism and glioma risk were inconsistent. Therefore, we performed a meta-analysis to assess the association between ACE I/D polymorphisms and glioma risk.Methods and Results:In total, four populations (1110 cases and 1335 controls) on ACE I/D polymorphism were included. Overall, the meta-analysis demonstrated no significant association between ACE I/D polymorphism and glioma risk. In addition, the analysis of the association of ACE I/D polymorphism and clinical grade also showed no significant association.Conclusion:Our meta-analysis didn’t find a significant association between ACE I/D polymorphism glioma risk. However, further studies with larger sample size and more ethnic groups are required to confirm the results.

MiR-499 rs3746444 and miR-196a-2 rs11614913 Are Associated with the Risk of Glioma, but Not the Prognosis

Previous studies of correlations of microRNA (miR)-499 rs3746444 and miR-196a-2 rs11614913 polymorphisms with glioma risk have yielded inconsistent results. In this study, relationships between these two polymorphisms and glioma risk and survival were evaluated. In total, 605 patients and 1,300 controls were genotyped. rs3746444 increased glioma risk in five genetic models (GA versus AA, odds ratio [OR], 95% confidence interval [CI] = 1.31 [1.05–1.66], p = 0.02; GG versus AA, OR [95% CI] = 10.70 [6.13–18.69], p < 0.0001; GA + GG versus AA, OR [95% CI] = 1.82 [1.47–2.24], p < 0.0001; GG versus AA + GA, OR [95% CI] = 9.99 [5.74–17.40], p < 0.0001; G versus A, OR [95% CI] = 2.18 [1.82–2.60], p < 0.0001). rs11614913 decreased glioma risk in a recessive model (OR [95% CI] = 0.79 [0.64–0.97], p = 0.03). No relationships between either SNP and survival were found. rs3746444 in the miR-499 seed region could affect target recognition. Bioinformatics analyses indicated that miR-499 rs3746444 is involved in various biological processes and pathways, including “cell adhesion molecule binding,” “positive regulation of catabolic process,” “NF-kappa B pathway,” and “PI3K-Akt pathway,” by targeting mRNAs. Our results suggested that miR-499 rs3746444 and miR-196a-2 rs11614913 have crucial roles in glioma susceptibility.

Associations of lncRNA H19 Polymorphisms at MicroRNA Binding Sites with Glioma Susceptibility and Prognosis

Glioma is the most common tumor of the central nervous system; variation in susceptibility and prognosis worldwide suggests that there are molecular and genetic differences among individuals. The H19 gene plays a dual role in carcinogenesis. In this study, associations between H19 polymorphisms and susceptibility as well as prognosis in glioma were evaluated. In total, 605 patients with glioma and 1,300 cancer-free subjects were enrolled in the study. Individuals with the rs3741219 A>G allele were less likely to develop glioma (relative risk [RR] = 0.54, 95% confidence interval [95% CI] = 0.45–0.63, p < 0.001), whereas rs217727 G>A and rs2839698 G>A genotypes were not associated with glioma risk. The associations between H19 polymorphisms and prognosis were assessed, including overall survival and progression-free survival. Three focused H19 polymorphisms did not show a significant effect on survival. Further analysis based on false-positive report probability validated these significant results. In the haplotype analysis, individuals with the Grs217727Ars2839698Grs3741219 haplotype were less likely to develop glioma (odds ratio [OR] = 0.33, 95% CI = 0.23–0.46, p = 0.02). Overall, carriers of the rs3741219 AG or GG genotype of H19 have a decreased susceptibility to glioma, but polymorphisms in this gene are not related to prognosis.

A Weighted Genetic Risk Score of Adult Glioma Susceptibility Loci Associated with Pediatric Brain Tumor Risk

Genetic risk score (GRS) is used to demonstrate the genetic variants contributing to the polygenic architecture of complex diseases. By using a GRS, we have investigated the additive impact of the known adult glioma susceptibility loci on the pediatric brain tumor (PBT) risk and assessed the proportion of PBT heritability attributable to these susceptibility loci. A GRS was generated for PBTs based on the alleles and associated effect sizes derived from a previously published genome-wide association study on adult glioma. The GRS was calculated in CEFALO, a population-based case-control study of brain tumors in children and adolescents including saliva DNA of 245 cases and 489 controls. The unconditional logistic regression model was used to investigate the association between standardized GRS and risk of PBTs. To measure the variance explained by the effect of GRS, Nagelkerke pseudo-R2 was calculated. The GRS for adult brain tumors was associated with an increased risk of PBTs (OR 1.25 [95% CI 1.06–1.49], p = 0.009) and 0.3% of the variance in PBTs could be explained by the effect of GRS on the liability scale. This study provides evidence that heritable risks of PBTs are in-part attributable to some common genetic variants associated with adult glioma.

Genetic Predisposition to Glioma Mediated by a MAPKAP1 Enhancer Variant.

Mitogen-activated protein kinase-associated protein 1 (MAPKAP1) is a unique component of the mechanistic target of rapamycin (MTOR) pathway which plays a pivotal role in carcinogenesis. The role of enhancer variant in carcinogenesis receives increased attentions. However, the significance of enhancer variants of MAPKAP1 in glioma has not yet been investigated. The associations of enhancer variants of MAPKAP1 with glioma susceptibility were evaluated in a cohort of 400 glioma patients and 651 controls. The function of glioma susceptibility locus was examined by a set of biochemical assays. We found that an enhancer variant of MAPKAP1 rs473426 was associated with a significantly increased risk of glioma in a dominant manner (OR 1.53, 95% CI 1.13-2.06; P = 0.006). The association for rs1339499 located in the same enhancer approached the borderline of significance after multiple testing correction (OR 0.74, 95% CI 0.56-0.98; P = 0.037). Furthermore, cumulative associations of rs473426 and rs1339499 with glioma risk were observed (P = 0.011). Functional analyses showed that the risk allele rs473426 C downregulated the regulatory activity of enhancer by reducing the binding affinity of a transcriptional activator NFΙC, which resulted in lower gene expression both in vitro and in vivo. These results demonstrate for the first time that enhancer variant of MAPKAP1 confers susceptibility to glioma by downregulation of MAPKAP1 expression, and provide further evidence highlighting MAPKAP1 as a cancer suppressor in glioma carcinogenesis.

Impact of AKAP6 polymorphisms on Glioma susceptibility and prognosis

PurposeGlioma is the most common primary malignant brain tumor with high mortality and poor prognosis. Our aim was to clarify the correlation between Kinase-anchored protein 6 (AKAP6) gene polymorphisms and glioma susceptibility and prognosis in Chinese Han population.MethodsFive single-nucleotide polymorphisms (SNPs) of AKAP6 were genotyped by Agena MassARRAY in 575 glioma patients and 500 healthy controls. Logistic regression model was utilized to calculate odds ratios (OR) and 95% confidence intervals (CI). The associations between polymorphisms and survival were assessed using the log-rank test, Kaplan-Meier analysis and Cox regression model.ResultsWe found that rs2239647 polymorphism was strongly associated with an increased risk of glioma (OR = 1.90, p = 0.007) and a worse prognosis for glioma, especially in high-grade glioma (HR = 1.67, p = 0.034). Stratified analysis showed that rs2239647 increased the risk of glioma in female (OR = 1.62, p = 0.016). Whereas, rs4261436 (HR = 0.70, p = 0.045) and rs17522122 (HR = 0.75, p = 0.016) were associated with better prognosis of astrocytoma. In addition, we also found that surgical methods and chemotherapy are critical factors for the prognosis of glioma patients.ConclusionsThis study firstly provided evidence for the impact of AKAP6 polymorphisms on susceptibility and prognosis of glioma, suggesting AKAP6 variants might have potential roles in the etiology of glioma.

Replication of GWAS identifies RTEL1, CDKN2A/B, and PHLDB1 SNPs as risk factors in Portuguese gliomas patients.

Diffuse gliomas are the most common malignant primary brain tumors and remain incurable. A better knowledge of the tumor etiology is required. Specific single nucleotides polymorphisms (SNPs) rs4977756 (CDKN2A/B), rs6010620 (RTEL1), rs498872 (PHLDB1), rs2736100 (TERT), and rs4295627 (CCDC26) have been associated with glioma susceptibility and are potential risk biomarkers. This study aimed to analyze five SNPs associated with glioma susceptibility, in the Portuguese population. SNPs were genotyped using the Sequenom MassARRAY platform in 127 gliomas and 180 controls. Unconditional logistic regression models were used to calculate odds ratio (OR) and 95% confidence intervals. The false-positive report probability was also assessed. The associations between polymorphisms and survival were evaluated using the log-rank test. It was found that the AG and GG genotypes of the rs4977756 (CDKN2A/B) were associated with an increased risk of gliomas (OR 1.85 and OR 2.38) and glioblastomas (OR 2.77 and OR 3.94). The GA genotype of the rs6010620 (RTEL1) was associated with a decreased risk of glioblastomas (OR 0.45). We also observed that the GA genotype of the rs498872 (PHLDB1) was associated with an increased risk of gliomas (OR 2.92) and glioblastomas (OR 2.39). No significant risk associations were found for the rs2736100 (TERT) and rs4295627 (CCDC26). In addition, the genotype AA of the rs498872 (PHLDB1) was associated with poor overall survival of gliomas patients (AA vs. GA, p = 0.037). The rs6010620 (RTEL1), rs4977756 (CDKN2A/B), and rs498872 (PHLDB1) are associated with glioma risk in the Portuguese population and these data may contribute to understanding gliomas etiology.

Effects of the MAML2 genetic variants in glioma susceptibility and prognosis

Background: Abnormal expression of the mastermind-like transcriptional co-activator 2 (MAML2) gene is oncogenic in several human cancers, including glioma. However, the relevance of MAML2 variants with glioma remains unknown. We aimed to investigate the role of MAML2 polymorphisms in glioma risk and prognosis among the Chinese Han population. Methods: Seven MAML2 single-nucleotide polymorphisms (SNPs) were genotyped using Agena MassARRAY system among 575 patients with glioma and 500 age- and gender-matched healthy controls. Logistic regression was used to estimate the association between MAML2 polymorphisms and glioma risk by calculating odds ratios (ORs) and 95% confidence intervals (CI). Kaplan–Meier survival analysis and univariate, multivariate Cox proportional hazard regression analyses for hazard ratios (HRs) and 95% CIs were performed to evaluate the contribution of MAML2 polymorphisms to glioma prognosis. Results: MAML2 rs7938889 and rs485842 polymorphisms were associated with the reduced risk of glioma (OR = 0.69, P=0.023; and OR = 0.81, P=0.032, respectively). Rs7115578 polymorphism had a lower susceptibility to glioma in males (OR = 0.68, P=0.034), while rs4598633 variant with a higher risk in females (OR = 1.66, P=0.016). Additionally, rs7115578 AG genotype represented a poorer prognosis of glioma (HR = 1.24, P=0.033) and astrocytoma (log-rank P=0.037, HR = 1.31, P=0.036). Furthermore, rs11021499 polymorphism had lower overall survival (OS) and progression-free survival (PFS) in patients with low-grade glioma. Conclusion: We provided some novel data suggesting MAML2 polymorphisms might contribute to glioma risk and prognosis. Future studies are warranted to validate these findings and characterize mechanisms underlying these associations.

Association Between Genetic Polymorphisms In TYMS And Glioma Risk In Chinese Patients: A Case-Control Study.

BackgroundThymidylate synthase (TYMS) polymorphisms are reported to be related to susceptibility to some cancers. However, no study exists on TYMS polymorphisms and glioma risk. This study aimed to evaluate the relationship between two common TYMS gene variants (rs1059394 C>T, rs2847153 G>A) and glioma susceptibility.MethodsThis case-control study included 605 patients and 1300 cancer-free individuals. Genotyping was performed using Sequenom Mass-ARRAY. We determined odds ratios (ORs) and their 95% confidence intervals (CIs) to estimate the correlations.ResultsThe analysis revealed that rs1059394 TT and CT+TT genotype had significantly low glioma risk (TT to CC: OR = 0.71, 95% CI = 0.52–0.97, P = 0.03; CT+TT to CC: OR = 0.74, 95% CI = 0.55–0.99, P = 0.04). However, no significant difference was found between rs2847153 and glioma risk in any genetic model (P﹥0.05). In high-grade gliomas, the GA and GA+AA genotypes of rs2847153 made the majority of genotypes, compared with GG genotype (GA to GG: OR = 2.01, 95% CI = 1.39–2.91, P < 0.001; GA+AA to GG: OR = 1.78, 95% CI =1.25–2.54, P < 0.001). Moreover, online expression quantitative trait locus (eQTL) analysis indicated that these two polymorphisms may alter TYMS gene expression in transformed fibroblast cells.ConclusionOur study provides evidence of the effect of TYMS rs1059394 on the susceptibility of glioma. In high-grade gliomas, compared with GG genotype, the GA and GA+AA genotypes of rs2847153 comprise a larger proportion.

Impact of four lncRNA polymorphisms (rs2151280, rs7763881, rs1136410, and rs3787016) on glioma risk and prognosis: A case-control study.

Long noncoding RNA (lncRNA) polymorphisms are reportedly in connection with tumor susceptibility and prognosis. Glioma is one of the most aggressive and common cancers of the central nervous system. This study aimed to investigate the relationship between four lncRNA variants and glioma susceptibility and prognosis in a Chinese Han population. Sequenom Mass-ARRAY was used to genotype 605 patients with glioma and 1300 cancer-free individuals. Odds ratios or hazard ratios and related 95% confidence intervals were calculated to estimate the correlations. Logistic and Cox regression models, log-rank tests, and Kaplan-Meier curves were used for the statistical analysis. Six inheritance models showed that ANRIL rs2151280 variant genotype (A>G) was related to the susceptibility of glioma, while the other three lncRNAs showed no association. Patients treated with temozolomide or nimustine had better progression-free survival (PFS) and overall survival (OS) than those treated with platinum. Besides, patients aged older than 40 years showed a poorer OS. The Cox multivariate analysis revealed that the rs1136410 GG genotype (A>G) was beneficial for OS and PFS. The Kaplan-Meier analyses indicated that rs1136410 A>G and the rs7763881 A>C were associated with longer OS. ANRIL rs2151280 variant genotype might increase susceptibility of glioma. In addition, PARP1 rs1136410 variant genotype could be beneficial for the overall survival of patients with glioma. More research data are needed to further validate our results.

GOLGA7 rs11337, a Polymorphism at the MicroRNA Binding Site, Is Associated with Glioma Prognosis

MicroRNAs bind to the 3′ untranslated regions of mRNAs, affecting translation, tumorigenesis, and apoptosis. This study evaluated the role of TYMS (rs1059394, C > T, and rs2847153, G > A), RYR3 (rs1044129, G > A), KIAA0423 (rs1053667, T > C), and GOLGA7 (rs11337, G > T) polymorphisms for assessment of glioma risk and prognosis among the Chinese Han population. Five single-nucleotide polymorphisms were assessed in 605 glioma patients and 1,300 controls. We found a significant correlation between rs1059394 and glioma susceptibility in the homozygote and dominant genetic models (TT versus CC, odds ratio [OR] = 0.71, 95% confidence interval [CI] = 0.52–0.97, p = 0.03; CT+TT versus CC, OR = 0.74, 95% CI = 0.55–0.99, p = 0.04). The results of the Kaplan-Meier and log rank tests revealed that the rs11337 GG genotype correlated with better overall survival of glioma patients (p = 0.017) than the GT genotype. Multivariate Cox regression analysis results also showed that the rs11337 GT genotype correlated with worse overall survival (p = 0.017, hazard ratio [HR] = 1.25, 95% CI = 1.04–1.5) than the GG genotype. These results suggest that GOLGA7 (rs11337) polymorphism may play a role in the prognosis of glioma patients and that TYMS (rs1059394) is associated with glioma risk.

Two novel genetic variants in the STK38L and RAB27A genes are associated with glioma susceptibility.

Glioma is the most common malignant primary brain tumors with poor prognosis. Genome wide association studies (GWAS) of glioma in populations with Western European ancestry were completed in the US and UK. However, our previous results strongly suggest the genetic heterogeneity could be important in glioma risk. To systematically investigate glioma risk-associated variants in Chinese population, we performed a multistage GWAS of glioma in the Han Chinese population, with a total of 3,097 glioma cases and 4,362 controls. In addition to confirming two associations reported in other ancestry groups, this study identified one new risk-associated locus for glioma on chromosome 12p11.23 (rs10842893, pmeta = 2.33x10-12, STK38L) as well as a promising association at 15q15-21.1 (rs4774756, pmeta = 6.12x10-8, RAB27A) in 3,097 glioma cases and 4,362 controls. Our findings demonstrate two novel association between the glioma risk region marked by variant rs10842893 and rs4774756) and glioma risk. These findings may advance the understanding of genetic susceptibility to glioma.

Shuttling SLC2A4RG is regulated by 14-3-3θ to modulate cell survival via caspase-3 and caspase-6 in human glioma.

BackgroundGlioma is the most common and aggressive primary brain tumor with polygenic susceptibility. The cytoplasmic/nuclear shuttling protein, SLC2A4RG (SLC2A4 regulator), has been identified in the 20q13.33 region influencing glioma susceptibility by genome-wide association studies (GWAS) and fine mapping analyses.MethodsTo discover the expression of SLC2A4RG and its relationship with patient prognosis, tissue microarray containing glioma samples and normal brains was constructed followed by immunohistochemical staining. The role of SLC2A4RG on cell proliferation, cell cycle, and apoptosis was evaluated by gain- and loss-of-function assays in vivo, and subcutaneous and intracranial xenografts were performed to assess its functional effects. The mechanism underlying SLC2A4RG was further investigated via luciferase reporter analyses, ChIP, mass spectrometry, Co-IP, immunofluorescence, etc.FindingsThe potential tumor suppressor role of SLC2A4RG was further validated by in vitro and in vivo experiments that SLC2A4RG could attenuate cell proliferation via G2/M phase arrest and induce glioma cell apoptosis by direct transactivation of caspase-3 and caspase-6. Moreover, its function displaying showed to depend on the nuclear transportation of SLC2A4RG, however, bound with 14-3-3θ, it would be sequestered in the cytoplasm followed by reversal effect.InterpretationWe identify a new pro-oncogenic mechanism whereby 14-3-3θ negatively regulates the nuclear function of the tumor suppressor SLC2A4RG, with significant therapeutic implications for the intervention of human glioma.FundThis work was supported by the National Natural Science Foundation of China (81372706, 81572501, and 81372235).

Allergy may confer better survival on patients with gliomas

ObjectivesGlioma susceptibility is inversely related to a history of allergies and atopy. Lung allergies are associated with 30% lower glioma susceptibility, compared to no lung allergies. Asthma and eczema also reduce the chance of glioma. However, the effect of allergy on glioma survival is not well characterized. Because of the allergy-glioma inverse relationship we examined the association of allergy with glioma survival in The Cancer Genome Atlas (TCGA). Patients and methodsWe evaluated the association between allergy and overall survival in TCGA Glioma (LGG) dataset. In order to have a sample of sufficient size to analyze, we classified as allergic any patient who answered yes to any of the manifestations of allergy that were queried. ResultsWe analyzed data from 526 patients with glioma. History of allergy conferred a survival advantage on glioma patients, when stratified by tumor histologic grade (p = 0.049). Because allergy confers a favorable prognosis, we performed Cox regression. The effect of allergy on survival was significant (p = 0.025, HR 0.525, 95% CI 0.299–0.924), independent of the effect of chromosome 1p (p < 0.001, HR 93.4, 95% CI 16–546) and 19q (p = 0.801, HR 1.2, 95% CI 0.23–6.9) codeletion or TP53 mutation (p = 0.015, HR 2.7, 95% CI 1.2–5.9), unrelated to TERT expression (p = 0.365, HR 1.1, 95% CI 0.89–1.4) or ATRX mutation (p = 0.904, HR 1.04, 95% CI 0.51–2.14), independent of tumor grade (grade 2 versus grade 3, p = 0.004, HR 2.2, 95% CI 1.3–3.8), not independent of histology (oligodendroglioma and oligoastrocytoma, NOS versus astrocytoma, p = 0.08, HR 0.62, 95% CI 0.36–1.1). Diminished RNA expression of three loci, having reproducible genetic associations with allergic disease risk, are significantly associated with increased survival in glioma: FOSL2, APOBR, and NCF4. Diminished NCF4 copy number is significantly associated with reduced survival (D). ConclusionOur finding of the improved prognosis that allergy confers on glioma increases the potential importance of understanding the allergy-glioma inverse association. If the mechanism could be more clearly elucidated, new, more effective treatments and preventive measures may be developed. Further studies are warranted.

Impact of ANXA5 polymorphisms on glioma risk and patient prognosis.

Glioma, the most common primary malignant brain tumor, is highly malignant with a poor prognosis. We aimed to clarify the relevance of ANXA5 polymorphisms to glioma risk and prognosis among the Chinese Han population. Six single-nucleotide polymorphisms (SNPs) of ANXA5 were genotyped by Agena MassARRAY in 593 glioma patients and 589 healthy controls. Logistic regression model was used to calculate odds ratios (OR) and 95% confidence intervals (CI). The association between polymorphisms and survival were evaluated using the log-rank test, Kaplan-Meier analysis and Cox regression model. We found that rs117677079 polymorphism was strongly associated with an increased risk of glioma (OR 1.64, p = 0.003) and a worse prognosis for glioma, especially in high-grade glioma (HR 1.76, p = 0.005). Whereas, rs145619195 CT genotype might weaken the susceptibility (OR 0.63, p = 0.024) and prognosis (HR 0.20, p = 0.025) of glioma. Haplotype analysis showed that haplotype ″GACCG″ in the block (rs41278075, rs2306420, rs117677079, rs2306415 and rs1131239) significantly decreased the susceptibility of glioma (OR 0.61, p = 0.003). Furthermore, we also found that age, extent of resection and chemotherapy were key prognostic factors in glioma patients. This study firstly provided evidence for the impact of ANXA5 polymorphism on the susceptibility and prognosis of glioma, suggesting ANXA5 variants might have potential roles in the etiology of glioma.

Association analysis of RTEL1 variants with risk of adult gliomas in a Korean population.

Previous studies have identified multiple loci for inherited susceptibility to glioma development, including the regulator of telomere elongation helicase 1 (RTEL1). However, the association between RTEL1 variants and risk of glioma has not been well understood. Therefore, we sought to comprehensively examine the genetic interaction between RTEL1 variants and risk of glioma with respect to defined histological and molecular subtypes. We employed a case-control study involving 250 adult glioma patients with previous molecular alterations and 375 population–based controls within Korean populations. Statistical analyses on the association between RTEL1 single nucleotide polymorphisms (SNPs) and glioma risk were conducted using unconditional logistic regression. Additional conditional and stepwise analyses were performed on significant RTEL1 SNPs. We detected significant associations (Bonferroni P < .05) between six SNPs (rs6089953, rs3848669, rs6010620, rs3787089, rs6062302, and rs115303435) and risk of glioma in the Korean subjects. The two coding variants, rs6062302 (D664D) and rs115303435 (A1059T), were plausibly causal variants and were independent among the significantly associated RTEL1 variants. The glioma subgroup analyses showed that the causal variants (rs6062302 and rs115303435) may be associated with increased risk of glioma regardless of histological grades and molecular alterations. This study provides a deeper understanding of relationships between RTEL1 variants and risk of glioma. Further studies are required to ascertain the impact of those variants on glioma susceptibility.

PDCT-06. PHASE 1 STUDY OF ONC201 IN PEDIATRIC PATIENTS WITH H3 K27M-MUTANT HIGH GRADE GLIOMA OR NEWLY DIAGNOSED DIPG

The imipridone ONC201 is the first selective antagonist of DRD2 for clinical oncology. Several Phase 1, Phase 1/2 and Phase 2 studies in patients with advanced cancers have established the single agent recommended Phase 2 dose (RP2D) of 625mg ONC201 administered orally once a week in adults. ONC201 induces p53-independent apoptosis in newly diagnosed and recurrent high-grade glioma in vitro, ex vivo and in vivo. Furthermore, radiographic regressions in adult recurrent H3 K27M-mutant glioblastoma patients in response to single agent ONC201 have been reported. Based on this adult experience and complementary preclinical results demonstrating the increased susceptibility of H3 K27M-mutant gliomas to ONC201, we initiated the first Phase 1 pediatric clinical trial of ONC201 January 30, 2018. This trial will determine the safety and RP2D of ONC201 in pediatric post-radiation H3 K27M-mutant glioma patients as a single agent and in newly diagnosed diffuse intrinsic pontine glioma (DIPG) patients in combination with radiation ({type:clinical-trial,attrs:{text:NCT03416530,term_id:NCT03416530}}NCT03416530). Patients without known H3 K27M-mutation status by a CLIA-lab can enroll with commitment to post-term biopsy. This is a multicenter, open-label, 2 arm, dose-escalation and dose-expansion study. Ten children with H3 K27M-mutant gliomas ages 5–18 years have been treated post-radiation: 3 at dose level 1; 3 at dose level 2; 4 as part of the dose expansion cohort on dose level 2. Patients have received 2–12 doses (median= 5). The ONC201 has been tolerated very well. Grade III/IV events include: decreased neutrophil count grade III (n=1) spontaneously resolved without dose modification and elevated AST grade III (n=1) returned to grade II after holding 1 dose. Additional safety data as well as pharmacokinetics, pharmacodynamics, and progression-free survival results from this trial will be reported.

Shuttling SLC2A4RG is Regulated by 14-3-3θ¸ to Modulate Cell Survival Via Caspase-3 and Caspase-6 in Human Glioma

Glioma is the most common and aggressive primary brain tumor with polygenic susceptibility. The cytoplasmic/nuclear shuttling protein, SLC2A4RG (SLC2A4 regulator), has been identified in the 20q13.33 region influencing glioma susceptibility by genome-wide association studies (GWAS) and fine mapping analyses. In this study, we revealed that nuclear SLC2A4RG was significantly decreased in human glioma specimens and associated with patients' unfavorable prognosis. The potential tumor suppressor role of SLC2A4RG was further validated by in vitro and in vivo experiments that SLC2A4RG could attenuate cell proliferation via G2/M phase arrest and induce glioma cell apoptosis by direct transactivation of caspase-3 and caspase-6. Moreover, its function displaying showed to depend on the nuclear transportation of SLC2A4RG, however, bound with 14-3-3θ¸, it would be sequestered in the cytoplasm followed by reversal effect. We, therefore, identify a new pro-oncogenic mechanism whereby 14-3-3I¸ negatively regulates the nuclear function of the tumor suppressor SLC2A4RG, with significant therapeutic implications for the intervention of human glioma. Funding: This work was supported by the National Natural Science Foundation of China (81372706, 81572501, 81071739, 81372235, and 81201978). Declaration of Interest: No potential conflicts of interest were disclosed. Ethical Approval: The present study was approved by the Ethical Review Committee of SMMU.

An intronic genetic variation of MGMT affects enhancer activity and is associated with glioma susceptibility.

PurposeO6-methylguanine-DNA methyltransferase (MGMT) plays a crucial role in repairing damaged DNA caused by alkylating agents. A number of cancer susceptibility loci have been recognized as enhancer variants. This study aimed to explore the significance of enhancer variants of MGMT in glioma susceptibility.Patients and methodsA retrospective case-control study consisting of 150 glioma patients and 327 controls was conducted to test whether enhancer variants of MGMT are associated with glioma susceptibility. Genotypes were determined by Sequenom MassARRAY technology. Associations were estimated by logistic regression. Biochemical assays were used to examine the function of glioma susceptibility locus.ResultsWe found that the A allele of rs10764901, an intronic variant of MGMT, was associated with a significantly decreased risk of glioma. The rs10764901 AA genotype carriers had an OR of 0.49 (95% CI, 0.24–0.98; P=0.045) compared with the rs10764901 GG genotype. When the rs10764901 AG and AA genotypes were pooled for analysis, a significantly decreased risk of glioma was also found (OR, 0.63; 95% CI, 0.43–0.93; P=0.021). Functional analyses showed that the rs10764901 A allele drove a lower luciferase expression and had higher transcription factor binding affinity than the G allele.ConclusionAn enhancer variant of MGMT rs10764901 affects the regulatory activity of enhancer by altering the binding affinity of transcription factors and is associated with glioma susceptibility.