Polymorphisms in apoptosis and cell cycle control genes and risk of brain tumors in adults

Global fungal-host interactome mapping identifies host targets of candidalysin

Candidalysin, a cytolytic peptide toxin secreted by the human fungal pathogen Candida albicans, is critical for fungal pathogenesis. Yet, its intracellular targets have not been extensively mapped. Here, we performed a high-throughput enhanced yeast two-hybrid (HT-eY2H) screen to map the interactome of all eight Ece1 peptides with their direct human protein targets and identified a list of potential interacting proteins, some of which were shared between the peptides. CCNH, a regulatory subunit of the CDK-activating kinase (CAK) complex involved in DNA damage repair, was identified as one of the host targets of candidalysin. Mechanistic studies revealed that candidalysin triggers a significantly increased double-strand DNA breaks (DSBs), as evidenced by the formation of γ-H2AX foci and colocalization of CCNH and γ-H2AX. Importantly, candidalysin binds directly to CCNH to activate CAK to inhibit DNA damage repair pathway. Loss of CCNH alleviates DSBs formation under candidalysin treatment. Depletion of candidalysin-encoding gene fails to induce DSBs and stimulates CCNH upregulation in a murine model of oropharyngeal candidiasis. Collectively, our study reveals that a secreted fungal toxin acts to hijack the canonical DNA damage repair pathway by targeting CCNH and to promote fungal infection.

Polymorphism at codon 31 of CDKN1A (p21) as a predictive factor for bevacizumab therapy in glioblastoma multiforme

Glioblastoma (GBM), a prevalent and malignant brain tumor, poses a challenge in surgical resection due to its invasive nature within the brain parenchyma. CDKN1A (p21, Waf-1), a cyclin-dependent kinase inhibitor, plays a pivotal role in regulating cell growth arrest, terminal differentiation, and apoptosis. The existence of natural variants of CDKN1A has been associated with specific cancer types. In this retrospective study, our objective was to identify polymorphic variants of CDKN1A, specifically c.93C > A (codon 31 Ser31Arg), and investigate its potential impact within the scope of bevacizumab therapy for glioblastoma multiforme. This study involved a cohort of 139 unrelated adult Chinese GBM patients in Taiwan. Genomic DNA extracted from tumor samples was utilized for genotyping using the polymerase chain reaction (PCR) restriction fragment length polymorphism method (PCR-RFLP analysis). Through unconditional logistic regression analysis, odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were calculated. Our findings unveiled that among these GBM patients, the distribution of codon 31 polymorphisms was as follows: 23.02% were Serine homozygotes (Ser/Ser), 27.34% were Arginine homozygotes (Arg/Arg), and 49.64% were Serine/Arginine heterozygotes (Ser/Arg). While CDKN1A c.93C > A polymorphisms did not exhibit a direct association with overall survival in GBM patients, noteworthy survival benefits emerged among individuals with Arg/Arg and Arg/Ser genotypes who received combined concurrent chemoradiotherapy (CCRT) and bevacizumab treatment compared to those who underwent CCRT alone. Our findings indicate a significant involvement of the CDKN1A c.93C > A polymorphism in the development and onset of GBM, offering potential implications for the early prognostication of bevacizumab therapy outcomes.

Caspase 8 Expression Patterns in Meningiomas: A Tissue Microarray Digital Image Analysis

Background: Caspases (cysteine-aspartic proteases) represent a family of enzymes that critically influence cell homeostasis by being involved in inflammation and apoptosis mechanisms. Meningiomas demonstrate the most common intracranial primary central nervous system tumors in adults worldwide.

Aim: Our purpose was to explore the role of caspase 8 expression in meningiomas’ pathological features.

Materials and methods: A total of 50 meningioma cases were included in the study, comprising a broad spectrum of histopathological sub-types. An immunohistochemistry assay was applied on tissue microarray cores followed by digital image analysis.

Results: Overexpression of caspase 8 protein was observed in 21/50 (42%) cases, whereas the rest of them (29/50, 58%) demonstrated moderate to low levels of the molecule. Caspase 8 overall expression was statistically significantly correlated to grade of the examined tumors and to mitotic index (p=0.001,p=0.002, respectively).

Conclusions: Caspase 8 aberrant expression is observed in meningiomas associated with their differentiation grade and mitotic activity. Targeted therapeutic strategies focused on enhancing caspase 8 expression and also inducing the overall apoptotic activity should be a very promising approach in rationally handling sub-groups of meningioma patients.

The role of aquaporin 4 in brain tumors: implications for pathophysiology, diagnosis and therapy

Primary brain tumors are a heterogeneous group of tumors that arise from cells intrinsic to the central nervous system (CNS). Aquaporin-4 (AQP4) has been implicated in the pathogenesis of brain tumors. Previous reports have documented a relationship between AQP4 and several molecular pathways associated with the etiology of brain tumors, such as apoptosis, invasion and cell migration. AQP4 affects apoptosis via cytochrome C, Bad and Bcl-2, as well as invasion and migration via IDO1/TDO-Kyn-AhR axis, lncRNA LINC00461, miR-216a, miRNA-320a and MMPs. In addition, inhibition of AQP4 mitigates the progression of brain tumors. This review summarizes current knowledge and evidence regarding the relationship between AQP4 and brain tumors, and the mechanisms involved.

Association between tobacco substance usage and a missense mutation in the tumor suppressor gene P53 in the Saudi Arabian population

The tumor suppressor gene TP53 and its downstream genes P21 and MDM2 play crucial roles in combating DNA damage at the G1/S cell cycle checkpoint. Polymorphisms in these genes can lead to the development of various diseases. This study was conducted to examine a potential association between tobacco substance usage (TSU) and single-nucleotide polymorphism (SNP) at the exon regions of the P53, P21, and MDM2 genes by comparing populations of smokers and non-smokers from Saudi Arabia. P53 rs1042522 (C/G), P21 rs1801270 (A/C), and MDM2 rs769412 (A/G) were investigated by genotyping 568 blood specimens: 283 from male/female smokers and 285 from male/female non-smokers. The results obtained from the smokers and their control non-smokers were compared according to age, sex, duration of smoking, and type of TSU. Heterozygous CG, homozygous GG, and CG+GG genotypes, as well as the G allele of rs1042522 were significantly associated with TSU in Saudi smokers compared with non-smokers. The C allele frequency of rs1801270 was also associated with TSU in smokers (OR = 1.33, p = 0.049) in comparison with non-smokers, in younger smokers (≤29 years) (OR = 1.556, p = 0.03280) in comparison with non-smokers of the same age, in smokers who had smoked cigarettes for seven years or less (OR = 1.596, p = 0.00882), and in smokers who had consumed shisha (OR = 1.608, p = 0.04104) in comparison with the controls. However, the genotypic and allelic frequencies for rs769412 did not show significant associations with TSU in Saudis. The selected SNP of P53 was strongly associated with TSU and may be linked to TSU-induced diseases in the Saudi Arabian population.

Gene Expression, Network Analysis, and Drug Discovery of Neurofibromatosis Type 2-Associated Vestibular Schwannomas Based on Bioinformatics Analysis

Neurofibromatosis Type 2- (NF2-) associated vestibular schwannomas (VSs) are histologically benign tumors. This study aimed to determine disease-related genes, pathways, and potential therapeutic drugs associated with NF2-VSs using the bioinformatics method. Microarray data of GSE108524 were downloaded from the Gene Expression Omnibus (GEO) database, and differentially expressed genes (DEGs) were screened using GEO2R. The functional enrichment and pathway enrichment of DEGs were performed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes Genomes (KEGG). Furthermore, the STRING and Cytoscape were used to analyze the protein-protein interaction (PPI) network of all differentially expressed genes and identify hub genes. Finally, the enriched gene sets belonging to the identified pathways were queried against the Drug-Gene Interaction database to find drug candidates for topical use in NF2-associated VSs. A total of 542 DEGs were identified, including 13 upregulated and 329 downregulated genes, which were mainly enriched in terms of focal adhesion, PI3K-Akt signaling pathway, ECM-receptor interaction, Toll-like receptor signaling pathway, Rap1 signaling pathway, and regulation of actin cytoskeleton. 28 hub genes were identified based on the subset of PPI network, and 31 drugs were selected based on the Drug-Gene Interaction database. Drug discovery using bioinformatics methods facilitates the identification of existing or potential therapeutic drugs to improve NF2 treatment.

Both p53 codon 72 Arg/Arg and pro/Arg genotypes in glioblastoma multiforme are associated with a better prognosis in bevacizumab treatment

BACKGROUND

It has previously been shown that bevacizumab, when added to chemotherapy, improved overall survival in several cancers. In glioblastoma multiforme (GBM), bevacizumab increased progression-free survival and it is widely used for tumor recurrence, though it has failed to improve overall survival (OS) in controlled trials. However, an effective biomarker for predicting the prognosis of bevacizumab treatment has yet to be identified. This study, therefore, aimed to retrospectively analyze the polymorphisms of p53 codon 72 and the clinical characteristics of GBM specimens from Taiwanese patients.

METHODS

The polymorphisms of p53 codon 72 in 99 patients with GBM treated at Taichung Veterans General Hospital in Taiwan from 2007 to 2017 were analyzed using direct DNA sequencing and PCR-RFLP analysis.

RESULTS

We found that among these GBM patients, the distribution of codon 72 polymorphisms was 28.3% for proline homozygotes (Pro/Pro), 38.4% for arginine homozygotes (Arg/Arg), and 33.3% for proline/arginine heterozygotes (Pro/Arg). Although the polymorphisms of p53 codon 72 were not directly associated with the overall survival of GBM, both the Arg/Arg and Arg/Pro genotypes were associated with significant benefits in terms of overall survival in patients treated with CCRT plus bevacizumab compared to patients treated with CCRT alone.

CONCLUSIONS

This pilot study suggests that both the Arg/Arg and Arg/Pro genotypes of p53 codon 72 polymorphism may have value as independent prognostic or predictive parameters for bevacizumab treatment response and failure. Relatedly, the results of the study further demonstrate the utility of stratifying GBM patients according to bevacizumab sensitivity.

CHEK2 Mutation in Patient with Multiple Endocrine Glands Tumors. Case Report

BACKGROUND

Many studies show the occurrence of several multiple endocrine neoplasia syndromes caused by different mutations, for example, in MEN1 and RET genes. Nevertheless, there are less common mutations causing multiple endocrine glands tumors. Examples of such mutations are CHEK2 gene mutations, causing breast, kidney, gastric, colorectal, prostate, lung, ovarian, and thyroid cancers.

CASE DESCRIPTION

In 2005, a 30-year-old woman was admitted to the hospital due to uncontrolled hypertension and obesity. Performed tests have shown ACTH (adrenocorticotropic hormone)-independent micronodular adrenal hyperplasia (AIMAH) as a cause. In 2010, the further diagnostic analysis revealed Cushing's disease caused by ACTH-secreting pituitary microadenoma. Additionally, in 2011, the patient underwent the strumectomy of multinodular struma. Papillary thyroid carcinoma was found in the excised tissue. In 2018, transvaginal ultrasonography revealed a tumor of the right ovary. After a performed hysterectomy with bilateral salpingo-oophorectomy, the histopathology result has shown female adnexal tumors of probable Wolffian origin (FATWO) located in the broad ligament of the uterus. Due to the history of multiglandular diseases, the patient was referred to genetic testing. We found a positive pathogenic mutation in CHEK2-suppressor gene involved in DNA repair, cell cycle arrest, and apoptosis in response to DNA damage.

CONCLUSION

CHEK2 variants may predispose to a range of endocrine glands tumors, including those identified in our patient. Multiple endocrine glands tumors, as in the presented patient, are a serious problem of public health, due to numerous hospitalizations and necessary repeated surgical treatments. Moreover, the association between CHEK2 and ovarian cancer can be a serious problem with reproductive health.

Identification of co‑expression modules and hub genes of retinoblastoma via co‑expression analysis and protein‑protein interaction networks

Retinoblastoma is a common intraocular malignant tumor in children. However, the molecular and genetic mechanisms of retinoblastoma remain unclear. The gene expression dataset GSE110811 was retrieved from Gene Expression Omnibus. After preprocessing, coexpression modules were constructed by weighted gene coexpression network analysis (WGCNA), and modules associated with clinical traits were identified. In addition, functional enrichment analysis was performed for genes in the indicated modules, and protein-protein interaction (PPI) networks and subnetworks were constructed based on these genes. Eight coexpression modules were constructed through WGCNA. Of these, the yellow module had the highest association with severity and age (r=0.82 and P=3e-07; r=0.72 and P=3e-05). The turquoise module had the highest association with months (r=−0.63 and P=5e-04). The genes in the two modules participate in multiple pathways of retinoblastoma, and by combining the PPI network and subnetworks; 10 hub genes were identified in the two modules. The present study identified coexpression modules and hub genes associated with clinical traits of retinoblastoma, providing novel insight into retinoblastoma progression.

Cellular Environment Remodels the Genomic Fabrics of Functional Pathways in Astrocytes

We profiled the transcriptomes of primary mouse cortical astrocytes cultured alone or co-cultured with immortalized precursor oligodendrocytes (Oli-neu cells). Filters between the cell types prevented formation of hetero-cellular gap junction channels but allowed for free exchange of the two culture media. We previously reported that major functional pathways in the Oli-neu cells are remodeled by the proximity of non-touching astrocytes and that astrocytes and oligodendrocytes form a panglial transcriptomic syncytium in the brain. Here, we present evidence that the astrocyte transcriptome likewise changes significantly in the proximity of non-touching Oli-neu cells. Our results indicate that the cellular environment strongly modulates the transcriptome of each cell type and that integration in a heterocellular tissue changes not only the expression profile but also the expression control and networking of the genes in each cell phenotype. The significant decrease of the overall transcription control suggests that in the co-culture astrocytes are closer to their normal conditions from the brain. The Oli-neu secretome regulates astrocyte genes known to modulate neuronal synaptic transmission and remodels calcium, chemokine, NOD-like receptor, PI3K-Akt, and thyroid hormone signaling, as well as actin-cytoskeleton, autophagy, cell cycle, and circadian rhythm pathways. Moreover, the co-culture significantly changes the gene hierarchy in the astrocytes.

The Apoptosis Pathway and CASP8 Variants Conferring Risk for Acute and Overuse Musculoskeletal Injuries

Rotator cuff tendinopathy (RCT), anterior cruciate ligament (ACL) ruptures, and carpal tunnel syndrome (CTS), are examples of chronic (RCT and CTS) and acute (ACL ruptures) musculoskeletal soft tissue injuries. These injuries are multifactorial in nature, with several identified intrinsic and extrinsic risk factors. Previous studies have implicated specific sequence variants within genes encoding structural and regulatory components of the extracellular matrix of tendons and/ligaments to predispose individuals to these injuries. An example, includes the association of sequence variants within the apoptotic regulatory gene, caspase-8 (CASP8) with other musculoskeletal injury phenotypes, such as Achilles tendinopathy. The primary aim of this study was, therefore, to investigate previously implicated DNA sequence variants within CASP8: rs3834129 (ins/del) and rs1045485 (G/C), and the rs13113 (T/A) identified using a whole exome sequencing approach, with risk of musculoskeletal injury phenotypes (RCT, ACL ruptures, and CTS) in three independent studies. In addition, the aim was to implicate a CASP8 genomic interval in the modulation of risk of RCT, ACL ruptures, or CTS. It was found that the AA genotype of CASP8 rs13113 (T/A) was independently associated with increased risk for CTS. In addition, it was found that the del-C haplotype (rs3834129-rs1045485) was significantly associated with non-contact ACL ruptures, which is in alignment with previous research findings. Collectively, the results of this study implicate the apoptosis pathway as biologically significant in the underlying pathogenesis of musculoskeletal injury phenotypes. These findings should be repeated in larger sample cohorts and across different populations. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:680-688, 2020.

The predictive capability of immunohistochemistry and DNA sequencing for determining TP53 functional mutation status: a comparative study of 41 glioblastoma patients

Tumor protein 53 (p53) regulates fundamental pathways of cellular growth and differentiation. Aberrant p53 expression in glioblastoma multiforme, a terminal brain cancer, has been associated with worse patient outcomes and decreased chemosensitivity. Therefore, correctly identifying p53 status in glioblastoma is of great clinical significance. p53 immunohistochemistry is used to detect pathological presence of the TP53 gene product. Here, we examined the relationship between p53 immunoreactivity and TP53 mutation status by DNA Sanger sequencing in adult glioblastoma. Of 41 histologically confirmed samples, 27 (66%) were immunopositive for a p53 mutation via immunohistochemistry. Utilizing gene sequencing, we identified only eight samples (20%) with TP53 functional mutations and one sample with a silent mutation. Therefore, a ≥10% p53 immunohistochemistry threshold for predicting TP53 functional mutation status in glioma is insufficient. Implementing this ≥10% threshold, we demonstrated a remarkably low positive-predictive value (30%). Furthermore, the sensitivity and specificity with ≥10% p53 immunohistochemistry to predict TP53 functional mutation status were 100% and 42%, respectively. Our data suggests that unless reliable sequencing methodology is available for confirming TP53 status, raising the immunoreactivity threshold would increase positive and negative predictive values as well as the specificity without changing the sensitivity of the immunohistochemistry assay.

CCDN1 rs603965 polymorphism may serve as a genetic biomarker of brain tumor: A meta-analysis of 5,769 subjects

Introduction

Some studies already tried to assess the associations between cyclin D1 (CCND1) polymorphisms and brain tumor. However, the results of these studies were not consistent. Thus, we performed the present meta‐analysis to explore the relationship between CCND1 polymorphisms and brain tumor in a larger pooled population.

Methods

PubMed, Web of Science, Embase, and CNKI were searched for related articles. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the potential associations.

Results

Totally nine studies with 5,769 subjects were analyzed. A significant association with brain tumor susceptibility was observed for the rs603965 polymorphism in GG versus GA + AA (dominant comparison, p = 0.003, OR = 0.72, 95% CI 0.57–0.89, I² = 64%), AA versus GG + GA (recessive comparison, p = 0.004, OR = 1.46, 95% CI 1.13–1.88, I² = 67%), and G versus A (allele comparison, p = 0.0004, OR = 0.77, 95% CI 0.66–0.89, I² = 66%) in overall population. Further subgroup analyses by ethnicity yielded similar positive results in both Asians and Caucasians. Moreover, in stratified analyses by type of disease, we noticed that the rs603965 polymorphism was significantly associated with the susceptibility to glioma, but such positive results were not detected in pituitary adenoma or meningioma. Additionally, a significant association with tumor grade was also observed for the rs603965 polymorphism in G versus A (allele comparison, p = 0.02, OR = 0.74, 95% CI 0.59–0.95, I² = 26%).

Conclusions

Our findings suggested that CCND1 rs603965 polymorphism may serve as a potential genetic biomarker of brain tumor, especially for glioma.

CASP8, XRCC1, WRN, NF2, and BRIP1 Polymorphisms Analysis Shows Their Genetic Susceptibility for Meningioma Risk and the Association with Tumor-Related Phenotype in a Chinese Population

OBJECTIVE

To investigate 10 candidate single nucleotide polymorphisms (SNPs) in 5 genes (CASP8, XRCC1, WRN, NF2, and BRIP1) to confirm the association between the 5 genes and the meningioma risk in a Chinese population.

METHODS

We examined 10 candidate SNPs in 5 genes (CASP8, XRCC1, WRN, NF2, and BRIP1) to confirm the association between the 5 genes and the meningioma risk and tumor-related phenotype in 433 individuals, including 215 patients with meningioma and 218 controls.

RESULTS

The polymorphisms rs4968451T>G in BRIP1 were significantly associated with the risk of meningioma (TT vs. TG vs. GG additive, P = 0.005; TT+TG vs. GG dominant, P = 0.015; TT/GT+GG recessive, P = 0.034). The significant association was found only in females for BRIP1 rs4968451T>G (TT+TG vs. GG dominant, P = 0.001; TT/GT+GG recessive, P = 0.044). We observed no significant association between genotypes and the meningioma risk for the other 9 SNPs. Through genotype-phenotype analysis, the genotype of BRIP1 rs4968451T>G was also strongly associated with tumor-related phenotypes, including the tumor grade and tumor subtypes. BRIP1 rs4968451T>G was associated with markedly grade I meningioma risk (TT+TG vs. GG dominant, P = 0.008; TT/GT+GG recessive, P = 0.020). In addition, BRIP1 rs4968451T>G was associated with markedly meningothelial and transitional meningioma risk. Furthermore, the genotype of CAPS8, XRCC1, and NF2 was associated with different subtype of meningioma risk.

CONCLUSIONS

This study indicated a role for BRIP1 gene variations in meningioma and may be informative for future genetic or biological studies of meningioma. These findings will assist in further understanding the genetic cause for meningiomas and guide more effective biological interventions to facilitate meningiomas.

A Case-Control Study of the Genetic Variability in Reactive Oxygen Species-Metabolizing Enzymes in Melanoma Risk

Recent studies have shown that ultraviolet (UV)-induced chemiexcitation of melanin fragments leads to DNA damage; and chemiexcitation of melanin fragments requires reactive oxygen species (ROS), as ROS excite an electron in the melanin fragments. In addition, ROS also cause DNA damages on their own. We hypothesized that ROS producing and metabolizing enzymes were major contributors in UV-driven melanomas. In this case-control study of 349 participants, we genotyped 23 prioritized single nucleotide polymorphisms (SNPs) in nicotinamide adenine dinucleotide phosphate (NADPH) oxidases 1 and 4 (NOX1 and NOX4, respectively), CYBA, RAC1, superoxide dismutases (SOD1, SOD2, and SOD3) and catalase (CAT), and analyzed their associated melanoma risk. Five SNPs, namely rs1049255 (CYBA), rs4673 (CYBA), rs10951982 (RAC1), rs8031 (SOD2), and rs2536512 (SOD3), exhibited significant genotypic frequency differences between melanoma cases and healthy controls. In simple logistic regression, RAC1 rs10951982 (odds ratio (OR) 8.98, 95% confidence interval (CI): 5.08 to 16.44; p < 0.001) reached universal significance (p = 0.002) and the minor alleles were associated with increased risk of melanoma. In contrast, minor alleles in SOD2 rs8031 (OR 0.16, 95% CI: 0.06 to 0.39; p < 0.001) and SOD3 rs2536512 (OR 0.08, 95% CI: 0.01 to 0.31; p = 0.001) were associated with reduced risk of melanoma. In multivariate logistic regression, RAC1 rs10951982 (OR 6.15, 95% CI: 2.98 to 13.41; p < 0.001) remained significantly associated with increased risk of melanoma. Our results highlighted the importance of RAC1, SOD2, and SOD3 variants in the risk of melanoma.

Blood-tissue analysis of TP53 polymorphisms and survival of patients with glioma

BACKGROUND

The role of single nucleotide polymorphisms (SNPs) in TP53 in the pathogenesis of glioma is still debated. The aim of our study was to investigate the role of several TP53 SNPs in the risk of glioma and their possible role as prognostic biomarkers of overall and progression-free survival.

METHODS

We examined 12 SNPs in TP53 from peripheral blood and neoplastic tissue of patients with a diagnosis of glioma who underwent surgery from 2012 to 2015. Direct genomic sequencing of TP53 was performed to detect the presence of polymorphisms. We compared data with a matched cancer-free control group and the NCBI SNPs database. Overall and progression-free survival were analyzed in patients with glioblastoma subjected to gross total resection and concomitant radio-chemotherapy.

RESULTS

No association was observed with glioma susceptibility and overall survival. Two new SNPs were detected: c.97-46 G>A (intron 3) and c.783-31 A>G (intron 7). The number of SNPs observed was higher (21.4%) in blood than in tumoral samples. We observed a significant reduction in progression-free survival in patients with at least one exonic SNP.

CONCLUSIONS

We can hypothesize an involvement of TP53 SNPs in response mechanisms to adjuvant treatment that may affect progression-free survival. Moreover, our blood-tissue combined study revealed a significant difference in SNPs between blood and tumoral samples, probably due to glioma heterogeneity and genomic instability.

Lineage divergence of activity-driven transcription and evolution of cognitive ability

Excitation-transcription coupling shapes network formation during brain development and controls neuronal survival, synaptic function and cognitive skills in the adult. New studies have uncovered differences in the transcriptional responses to synaptic activity between humans and mice. These differences are caused both by the emergence of lineage-specific activity-regulated genes and by the acquisition of signal-responsive DNA elements in gene regulatory regions that determine whether a gene can be transcriptionally induced by synaptic activity or alter the extent of its inducibility. Such evolutionary divergence may have contributed to lineage-related advancements in cognitive abilities.

Single nucleotide polymorphisms rs701848 and rs2735343 in PTEN increases cancer risks in an Asian population

We performed this meta-analysis to analyze the cancer risk to individuals carrying the rs701848 and rs2735343 single nucleotide polymorphisms (SNPs) in the phosphatase and tensin homolog (PTEN) gene. We searched the PubMed, EMBASE, Cochrane library and the national knowledge infrastructure of China (CNKI) databases and identified 18 eligible case-control studies with 5458 cases and 6003 controls for rs701848 as well as 5490 cases and 6209 controls for rs2735343. Our analyses demonstrated that cancer risk was associated with rs701848 in the recessive model (CC vs. CT+TT, OR=1.169, 95% CI: 1.061-1.288) and with rs2735343 in the dominant model (GC+CC vs. GG, OR=0.758, 95% CI: 0.590-0.972). Subgroup analysis showed that in Asian subjects, carrying the C allele of rs701848 or GG genotype of rs2735343 was associated with increased cancer risk. Moreover, Asian subjects carrying the TC/CC genotype or C allele of rs701848 were associated with increased risk of esophageal squamous cell cancer. This meta-analysis indicates that the PTEN rs701848 (CC) and rs2735343 (GG) polymorphisms are associated with increased cancer risk in Asian subjects.

High expression of anti-apoptotic genes in grade I and II meningiomas

ABSTRACT One of the different genetic mechanisms involved in the carcinogenesis of meningiomas is influenced by interactions between proteins that induce and inhibit apoptosis. Objective To evaluate the expression of c-FLIP, XIAP, Bcl-2, caspase 3, 8 and 9, cytochrome c, APAF 1 and Smac/DIABLO genes related to apoptosis pathways. Methods The gene expression was evaluated in 30 meningiomas (WHO grades I and II) and in 10 normal samples (from arachnoid tissue) through PCR-RT. Results The results showed higher expression of anti-apoptotic genes in meningiomas when compared to the control group, which had a low expression of pro-apoptotic genes. Conclusion There is a possible block in the activation of caspases through the intrinsic apoptosis pathway in meningiomas. c-FLIP modulates caspase 8 and, by inhibiting its activation due to the lack of connection with the receiver, there is a block to the FAS activation of apoptosis by its extrinsic pathway.

Genetic variants and increased risk of meningioma: an updated meta-analysis

PURPOSE

Various genetic variants have been reported to be linked to an increased risk of meningioma. However, no confirmed conclusion has been obtained. The purpose of the study was to investigate potential meningioma-associated gene polymorphisms, based on published evidence.

MATERIALS AND METHODS

An updated meta-analysis was performed in September 2016. After electronic database searching and study screening, we selected eligible case-control studies and extracted data for meta-analysis, using Mantel-Haenszel statistics. P-values, pooled odds ratios (ORs), and 95% confidence intervals were calculated.

RESULTS

We finally selected eight genes with ten polymorphisms: MLLT10 rs12770228, CASP8 rs1045485, XRCC1 rs1799782, rs25487, MTHFR rs1801133, rs1801131, MTRR rs1801394, MTR rs1805087, GSTM1 null/present, and GSTT1 null/present. Results of meta-analyses showed that there was increased meningioma risk in case groups under all models of MLLT10 rs12770228 (all OR >1, P<0.001), compared with control groups. Similar results were observed under the allele, homozygote, dominant, and recessive models of MTRR rs1801394 (all OR >1, P<0.05), and the heterozygote and dominant models of MTHFR rs1801131 in the Caucasian population (all OR >1, P<0.05). However, no significantly increased meningioma risks were observed for CASP8 rs1045485, XRCC1 rs25487, rs1799782, MTHFR rs1801133, MTR rs1805087, or GSTM1/GSTT1 null mutations.

CONCLUSION

Our updated meta-analysis provided statistical evidence for the role of MLLT10 rs12770228, MTRR rs1801394, and MTHFR rs1801131 in increased susceptibility to meningioma.

Genetic variants in CHEK1 gene are associated with the prognosis of thoracic esophageal squamous cell carcinoma patients treated with radical resection

CHEK1 gene is known to play an important role in tumor progression by cell cycle control. However, the association between CHEK1 and the prognosis of esophageal squamous cell carcinoma (ESCC) is unclear. In this study, we explored the association between genetic variants in CHEK1 gene and prognosis of ESCC patients treated with radical resection. A total of 131 thoracic ESCC patients who underwent radical resection were included in this retrospective study and genotyped using the MassArray method. According to the univariate Cox hazard analysis, the GT/TT genotype of CHEK1 rs555752 was shown to be strongly related to a decreased overall survival (OS) (HR=2.560, 95% CI: 1.415-4.631, P=0.002) and disease-free survival (DFS) (HR=2.160, 95% CI: 1.258-3.710, P=0.005). Furthermore, according to the multivariate Cox hazard analysis and multiple testing, patients with the GT/TT genotype of CHEK1 rs555752 had a notably decreased OS (HR=2.735, 95% CI: 1.468-5.096, P=0.002, Pc=0.006) and DFS (HR=2.282, 95% CI: 1.292-4.023, P=0.004, Pc=0.012). In conclusion, genetic variants of the CHEK1 gene are significantly related to OS and DFS of ESCC patients, and may therefore be predictors of the prognosis of thoracic ESCC after surgery.

Common genetic variations in cell cycle and DNA repair pathways associated with pediatric brain tumor susceptibility

Knowledge on the role of genetic polymorphisms in the etiology of pediatric brain tumors (PBTs) is limited. Therefore, we investigated the association between single nucleotide polymorphisms (SNPs), identified by candidate gene-association studies on adult brain tumors, and PBT risk.The study is based on the largest series of PBT cases to date. Saliva DNA from 245 cases and 489 controls, aged 7-19 years at diagnosis/reference date, was genotyped for 68 SNPs. Data were analyzed using unconditional logistic regression.The results showed EGFRrs730437 and EGFRrs11506105 may decrease susceptibility to PBTs, whereas ERCC1rs3212986 may increase risk of these tumors. Moreover, stratified analyses indicated CHAF1Ars243341, CHAF1Ars2992, and XRCC1rs25487 were associated with a decreased risk of astrocytoma subtype. Furthermore, an increased risk of non-astrocytoma subtype associated with EGFRrs9642393, EME1rs12450550, ATMrs170548, and GLTSCRrs1035938 as well as a decreased risk of this subtype associated with XRCC4rs7721416 and XRCC4rs2662242 were detected.This study indicates SNPs in EGFR, ERCC1, CHAF1A, XRCC1, EME1, ATM, GLTSCR1, and XRCC4 may be associated with the risk of PBTs. Therefore, cell cycle and DNA repair pathways variations associated with susceptibility to adult brain tumors also seem to be associated with PBT risk, suggesting pediatric and adult brain tumors might share similar etiological pathways.

Correlations of PTEN genetic polymorphisms with the risk of depression and depressive symptoms in a Chinese population

OBJECTIVE

This study aimed to investigate the correlations of three common single nucleotide polymorphisms (SNPs) in the PTEN gene (rs701848 T>C, rs2735343 G>C and rs112025902 A>T) with the risk of depression and depressive symptoms in a Chinese population.

METHODS

From July 2011 to June 2013, a total of 384 patients with depression and 400 healthy individuals were included in this study. These SNPs in the PTEN gene were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and direct sequencing. The Hamilton Depression Rating Scale (HAMD) was used to evaluate the severity of depression.

RESULTS

The C allele of rs701848, the C allele of rs2735343 and the T allele of rs112025902 were associated with an increased risk of depression (odds ratio [OR]=3.814, 95% CI: 3.093-4.703, P<0.001; OR=2.642, 95% CI: 2.152-3.242, P<0.001; OR=2.882, 95% CI: 2.347-3.539, P<0.001; respectively). Depression patients carrying C allele (TC+CC) of rs701848 and carrying T allele (AT+TT) of rs112025902 had higher HAMD total scores and HAMD anxiety factor scores than those carrying TT genotype of rs701848 and carrying AA genotype of rs112025902 (all P<0.05). Furthermore, depression patients carrying C allele (GC+CC) of rs2735343 had lower HAMD total scores and HAMD factors associated with depression scores than those carrying GG genotype (both P<0.05). Logistic regression analysis revealed that rs701848, rs2735343 and rs112025902 polymorphisms in the PTEN gene may be independent risk factors of depression (relative risk [RR]=1.807, 95% CI=1.023-3.193, P=0.042; RR=1.759, 95% CI=1.033-2.995, P=0.038; RR=1.646, 95% CI=1.018-2.663, P=0.042; respectively).

CONCLUSION

Our findings provide evidence that rs701848, rs2735343 and rs112025902 polymorphisms in the PTEN gene may be correlated with the risk of depression and depressive symptoms in the Chinese population.

A Functional Polymorphism (rs937283) in the MDM2 Promoter Region is Associated with Poor Prognosis of Retinoblastoma in Chinese Han Population

The effect of single nucleotide polymorphisms (SNPs) at MDM2 has been investigated in several cancer types. Three MDM2 SNPs(rs937283, rs2270744 and rs769412) have previously been suggested to be positively correlated with cancer. In this study, we aimed to explore the association of rs937283, rs2270744 and rs769412 polymorphisms with retinoblastoma (RB) risk, clinicopathological characteristics, and prognosis. Compared with wild-type genotype AA at rs937283, individuals carrying AG and GG genotype had a significantly increased risk for developing RB (OR = 1.86, 95% CI 1.13–3.08; OR = 2.48, 95% CI 1.10–5.62, respectively). RB patients with allele G at rs937283 were more susceptible to invasion and high tumor aggression (OR = 2.42, 95% CI 1.43–4.11; OR = 2.15, 95% CI 1.27–3.64, respectively). Kaplan-Meier curves and log-rank results revealed that RB patients harboring genotype GG and G allele at rs937283 had worse survival (P < 0.02 and P < 0.01, respectively). In addition, the A to G substitution at rs937283 significantly enhanced the transcription activity of the MDM2 gene in vitro. In vivo, we found that MDM2 mRNA and protein were overexpressed in individuals who carried the G allele at rs937283. This study suggested that the MDM2 rs937283 polymorphism is a novel functional SNP both in vitro and in vivo as well as a biomarker for poor prognosis in RB.

Association Between Polymorphism rs678653 in Human Cyclin D1 Gene (CCND1) and Susceptibility to Cancer: A Meta-Analysis

Background

To assess the association between polymorphism rs678653 in human Cyclin D1 gene (CCND1) and the risk of cancer.

Material/Methods

Multiple biomedical databases were systematically searched. Pooled odds ratios (OR) and 95% confidence intervals (95% CIs) were calculated in the appropriate model.

Results

In total, 17 case-control studies from 14 articles were included. When combing all available data, no significant association of rs678653 with cancer risk was observed under different genetic models. Stratification by ethnicity also indicated that rs678653 was not correlated with cancer risk in Taiwanese or Indian populations. When stratified by cancer type, no significant association was found between polymorphism rs678653 and digestive tract cancer, head and neck cancer, and gynecological cancer risk.

Conclusions

Our comprehensive meta-analysis suggests that the polymorphism rs678653 in CCND1 has no association with cancer risk in different population and disease contexts, indicating that CCND1 rs678653 does not serve a significant biological function in predicting cancer risk.

Association Between ESR1 PvuII, XbaI, and P325P Polymorphisms and Breast Cancer Susceptibility: A Meta-Analysis

Background

Breast cancer is one of the leading causes of cancer-related deaths for women. Numerous studies have shown that single-nucleotide polymorphisms (SNPs) on the ESR1 gene are associated to this disease. However, data and conclusions are inconsistent and controversial.

Material/Methods

To investigate the association between PvuII (rs2234693), XbaI (rs9340799) and P325P (rs1801132) polymorphisms of ESR1 gene with the risk of breast cancer under different population categorizations, we searched multiple databases for data collection, and performed the meta-analysis on a total of 25 case-control studies. Three different comparison models – dominant model, recessive model, and homozygote comparison model – were applied to evaluate the association.

Results

Our results indicated that people with TT+TC or TT genotype were at a greater risk of developing breast cancer than those with CC genotype in the PvuII polymorphism. While for XbaI and P325P polymorphisms, no significance was found using any of the 3 models. Furthermore, the data were also stratified into different subgroups according to the ethnicity (white or Asian) and source of controls (hospital-based or population-based), and separate analyses were conducted to assess the association. The ethnicity subgroup assessment showed that the higher risk of breast cancer for TT genotype of PvuII polymorphism than CC genotype only occurred in Asian people, but not in white populations. For the source-stratified subgroup analysis, significant association suggested that people with TT + TC genotype were at a greater risk of developing breast cancer than those with CC genotype in the hospital-based subgroup.

Conclusions

Thus, this meta-analysis clarified the inconsistent conclusions from previous studies, conducted analyses for the entire population as well as for different subgroups using diverse population categorization strategies, and has the potential to help provide a personalized risk estimate for breast cancer susceptibility.

Survival and low-grade glioma: the emergence of genetic information

Significant gaps exist in our understanding of the causes and clinical management of glioma. One of the biggest gaps is how best to manage low-grade (World Health Organization [WHO] Grade II) glioma. Low-grade glioma (LGG) is a uniformly fatal disease of young adults (mean age 41 years), with survival averaging approximately 7 years. Although LGG patients have better survival than patients with high-grade (WHO Grade III or IV) glioma, all LGGs eventually progress to high-grade glioma and death. Data from the Surveillance, Epidemiology and End Results (SEER) program of the National Cancer Institute suggest that for the majority of LGG patients, overall survival has not significantly improved over the past 3 decades, highlighting the need for intensified study of this tumor. Recently published research suggests that historically used clinical variables are not sufficient (and are likely inferior) prognostic and predictive indicators relative to information provided by recently discovered tumor markers (e.g., 1p/19q deletion and IDH1 or IDH2 mutation status), tumor expression profiles (e.g., the proneural profile) and/or constitutive genotype (e.g., rs55705857 on 8q24.21). Discovery of such tumor and constitutive variation may identify variables needed to improve randomization in clinical trials as well as identify patients more sensitive to current treatments and targets for improved treatment in the future. This article reports on survival trends for patients diagnosed with LGG within the United States from 1973 through 2011 and reviews the emerging role of tumor and constitutive genetics in refining risk stratification, defining targeted therapy, and improving survival for this group of relatively young patients.

MDM2 (RS769412) G>A Polymorphism in Cigarette Smokers: a Clue for the Susceptibility to Smoking and Lung Cancer Risk

Cigarette smoke contains oxidants and free radicals which are carcinogens that can induce mutations in humans. Single nucleotide polymorphisms (SNPs) are the most frequent genetic alterations found in the human genome. In the present study, we have examined the ability of the murine double minute 2 (Mdm2) (rs769412) A>G polymorphism in cigarette smokers to predict risk of cancers. Our results showed that of smokers, 87% were found with AA genotype, 10% with heterozygous AG genotype, and 3% with GG genotype. The heterozygous AG genotype was observed in a lower percentage of smokers (10%) as compared to non-smokers (18%), whereas, homozygous AA genotype was observed in lower percentage of non-smokers (81%) as compared to the smokers (87%). The results from present study support the association with an allele and AG genotype in non-smokers. However, further studies are required to establish the role of Mdm2 (rs769412) C>T in cigarettes smokers and diseases.

The CCND1 G870A gene polymorphism and brain tumor risk: a meta-analysis

BACKGROUND

In recent years, numerous studies have been performed to investigate the CCND1 G870A gene polymorphism impact on brain tumors susceptibility. Unfortunately, the results of previous studies were inconsistent. Therefore, we performed a meta-analysis to derive a more precise estimation of any association.

MATERIALS AND METHODS

We conducted a search in PubMed, Embase and CNKI covering all published papers up to November, 2013. Odds ratios (ORs) and their 95% confidence intervals (95%CIs) were applied to assess associations.

RESULTS

A total of 6 publications including 9 case-control studies met the inclusion criteria. The pooled ORs for the total included studies showed significant association among comparison A vs G (OR= 1.246, 95%CI= 1.092-1.423, p= 0.001), homozygote comparison AA vs GG (OR= 1.566, 95%CI= 1.194-2.054, p= 0.001), heterozygote comparison AG vs GG (OR= 1.290, 95%CI= 0.934-1.782, p= 0.122), dominant model AA/GA vs GG (OR= 1.381, 95%CI= 1.048-1.821, p= 0.022) and recessive model AA vs GA/GG (OR= 1.323, 95%CI= 1.057- 1.657, p= 0.015) especially in glioma.

CONCLUSIONS

CCND1 G870A polymorphism may increase brain tumor risk, especially for gliomas. However, more primary large scale and well-designed studies are still required to evaluate the interaction of CCND1 G870A polymorphism with brain tumor risk.

P14ARF deficiency and its correlation with overexpression of p53/MDM2 in sporadic vestibular schwannomas

Recent studies have shed considerable light into schwannomas. To date, only merlin has been identified as a hallmark or pathogenesis of both sporadic and NF2-related schwannomas. Here, we show, by immunoblot and immunohistochemical analyses of 58 sporadic vestibular schwannomas, that upregulation of p53 was observed in 90 % of tumors examined. No p53 mutations were found in 12 % tumors analyzed. Expression of p14ARF was negative in 95 % of tumors, while overexpression of MDM2 was found in all specimens. Aberrant DNA hypermethylation of the p14ARF promoter was observed in three of seven tumors examined (43 %), associated with remarkably decreased mRNA levels. The very high degree of concordance in the aberrations of the p14ARF/MDM2/p53 pathway in this tumor may be considered to be a new player in the pathogenesis of sporadic vestibular schwannomas. Moreover, expression of p21 (waf1) was negative in all tumors, suggesting that the aberration of this pathway is associated with greater attenuation of p21-mediated signals that are critical for growth inhibition. These data are in agreement with the model in RT-4 rat schwannoma cells: i.e., overexpression of ARF was associated with accumulation of p21 expression both at protein and mRNA levels. ShRNA knock-down of p53 expression attenuated p21-mediated increase in cellular arrest in the G1-phase, suggesting that p14ARF regulates p21 protein levels through a p53-dependent pathway. Thus, this study reveals a high degree of concordance in the aberrations of the p14ARF/MDM2/p53 pathway with the development of sporadic vestibular schwannomas.

Association between the G870A polymorphism of Cyclin D1 gene and glioma risk

Previous studies have shown the association of the Cyclin D1 (CCND1) G870A polymorphism with glioma risk, but the findings are inconsistent and inconclusive. To shed some light on the findings across individual studies and acquire a quantitative assessment of this association, we conducted a meta-analysis of all published case-control studies thus far. Four independent studies with a total of 690 cases and 1,014 controls were identified after a systematic search of the PubMed, Embase, Web of Science, and Wanfang databases. The strength of the association between the CCND1 G870A polymorphism and glioma risk was estimated by the pooled odds ratios (ORs) with 95 % confidence intervals (95 %CIs). Subgroup analysis by ethnicity was also performed. Overall, a statistically significant association was found between the CCND1 G870A polymorphism and glioma risk in three genetic models (ORA vs. G = 1.178, 95 %CI 1.025-1.354, P OR = 0.021; ORAA vs. GG = 1.328, 95 %CI 1.007-1.750, P OR = 0.045; ORAA + AG vs. GG = 1.253, 95 %CI 1.006-1.516, P OR = 0.044). In subgroup analysis, the pooled ORs suggested that the CCND1 G870A polymorphism was associated with an increased risk of glioma in Caucasians under the heterozygote and dominant genetic models (ORAG vs. GG = 1.329, 95 %CI 1.001-1.766, P OR = 0.049; ORAA + AG vs. GG = 1.332, 95 %CI 1.019-1.740, P OR = 0.036). The meta-analysis suggests that the CCND1 G870A polymorphism is a risk factor for the development of glioma.

Cyclin D1 gene G870A variants and primary brain tumors

Alterations of cyclin D1, one of the main regulators of the cell cycle, are known to be involved in various cancers. The CCDN1 G870A polymorphism causes production of a truncated variant with a shorter half-life and thus thought to impact the regulatory effect of CCDN1. The aim of the present study was to contribute to existing results to help to determine the prognostic value of this specific gene variant and evaluate the role of CCDN1 G870A polymorphism in brain cancer susceptibility. A Turkish study group including 99 patients with primary brain tumors and 155 healthy controls were examined. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism analysis. The CCDN1 genotype frequencies in meningioma, glioma and control cases were not significantly different (p>0.05). No significant association was detected according to clinical parameters or tumor characteristics; however, a higher frequency of AG genotype was recorded within patients with astrocytic or oligoastrocytic tumors. A significant association between AG genotype and gliobilastoma multiforme (GBM) was recorded within the patients with glial tumors (p value=0.048 OR: 1.87 CI% 1.010-3.463). According to tumor characteristics, no statistically significant difference was detected within astrocytic, oligoasltrocytic tumors and oligodentrioglias. However, patients with astrocytic astrocytic or oligoastrocytic tumors showed a higher frequency of AG genotype (50%) when compared to those with oligodendrioglial tumors (27.3%). Our results indicate a possible relation between GBM formation and CCDN1 genotype.

Association of methionine synthase rs1801394 and methionine synthase reductase rs1805087 polymorphisms with meningioma in adults: A meta-analysis

Several epidemiological studies suggested that methionine synthase (MTRR) rs1801394 and methionine synthase reductase (MTR) rs1805087 polymorphisms may be involved in the risk of meningioma in adults; however, the results from different case-control studies have been inconsistent. Therefore, we performed a meta-analysis to investigate the association of MTRR and MTR polymorphisms with meningioma. PubMed, Web of Knowledge, China National Knowledge Infrastructure and Wanfang databases were searched up to October 30, 2013 and 3 publications, involving 7 case-control studies, were finally included. Following data extraction, a meta-analysis was conducted using Stata 12.0 software. The pooled results based on the fixed effects model demonstrated that the MTRR rs1801394 polymorphism was associated with an increased risk of meningioma [odds ratio (OR)=1.18, 95% confidence interval (CI): 1.05–1.32 for G vs. A; OR=1.41, 95% CI: 1.12–1.77 for GG vs. AA; OR=1.08, 95% CI: 0.94–1.33 for AG vs. AA; OR=1.19, 95% CI: 1.01–1.40 for (AG+GG) vs. AA; and OR=1.32, 95% CI: 1.07–1.63 for GG vs. (AG+AA)]; however, an association between the MTR rs1805087 polymorphism and the risk of meningioma was not identified [OR=0.99, 95% CI: 0.88–1.12 for G vs. A; OR=1.09, 95% CI: 0.80–1.48 for GG vs. AA; OR=0.95, 95% CI: 0.82–1.11 for AG vs. AA; OR=0.97, 95% CI: 0.84–1.13 for (AG+GG) vs. AA; and OR=1.09, 95% CI: 0.80–1.48 for GG vs. (AG+AA)]. Therefore, the currently available evidence suggests that the MTRR rs1801394 polymorphism may increase the risk of meningioma, whereas the MTRR rs1801394 polymorphism is not associated with meningioma.

Genetic association of CHEK2, GSTP1, and ERCC1 with glioblastoma in the Han Chinese population

Glioblastoma (GBM), a deadly brain tumor, is the most malignant glioma. It mainly occurs in adults and occurs significantly more in males than in females. We genotyped 19 tag single nucleotide polymorphisms (tSNPs) from 13 genes in a case-control study of the Han Chinese population to identify genetic factors contributing to the risk of GBM. These tSNPs were genotyped by Sequenom MassARRAY RS1000. Statistical analysis was performed using χ(2) test and SNPStats, a website software. Using χ(2) test, we found that the distribution of two tSNPs (rs2267130 in checkpoint kinase 2 (CHEK2), p = 0.040; rs1695 in GSTP1, p = 0.023) allelic frequencies had significant difference between cases and controls. When we analyzed all of the tSNPs using the SNPStats software, we found that rs1695 in GSTP1 decreased the risk of GBM in log-additive model (OR = 0.56, 95% CI, 0.34-0.94, p = 0.022). Besides, we found that there is an interaction between rs3212986 in excision repair cross-complementing group 1 (ERCC1) and gender under codominant and recessive models. The gene polymorphisms in CHEK2, GSTP1, and ERCC1 may be involved in GBM in the Han Chinese population. Since our sample size is small, further investigation needs to be performed.

Association between XRCC3 Thr241Met polymorphism and risk of brain tumors: a meta-analysis

X-ray repair cross-complementing group 3 (XRCC3) plays an important role in the process of homologous recombination repair for DNA double-strand breaks which further maintains the stability of the genome. XRCC3 Thr241Met polymorphism has been indicated in the development of cancers, but the association of the XRCC3 Thr241Met polymorphism with risk of brain tumors is still unclear owing to the conflicting findings from previous studies. We performed a meta-analysis to provide a better understanding on the association between the XRCC3 Thr241Met polymorphism and risk of brain tumors. The pooled odds ratio (OR) with corresponding 95 % confidence interval (95 % CI) was used to assess the association. Thirteen case-control studies involving a total of 4,984 cases and 7,472 controls were included. Overall, there was no statistically significant association between the XRCC3 Thr241Met polymorphism and risk of brain tumors under all contrast models. Subgroup analysis by race suggested that the XRCC3 Thr241Met polymorphism was associated with increased risk of brain tumors in Asians under all four contrast models (Met vs. Thr: OR = 1.22, 95 % CI 1.09-1.36, P < 0.01; MetMet vs. ThrThr: OR = 1.89, 95 % CI 1.38-2.57, P < 0.01; MetMet vs. ThrThr/ThrMet: OR = 1.78, 95 % CI 1.31-2.40, P < 0.01; and MetMet vs. ThrThr/ThrMet: OR = 1.19, 95 % CI 1.04-1.36, P = 0.01). However, there was no significant association between the XRCC3 Thr241Met polymorphism and risk of brain tumors in Caucasians. Therefore, the XRCC3 Thr241Met polymorphism is associated with increased risk of brain tumors, especially in Asians.

RTEL1 and TERT polymorphisms are associated with astrocytoma risk in the Chinese Han population

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.

Low penetrance susceptibility to glioma is caused by the TP53 variant rs78378222

Background:

Most of the heritable risk of glioma is presently unaccounted for by mutations in known genes. In addition to rare inactivating germline mutations in TP53 causing glioma in the context of the Li-Fraumeni syndrome, polymorphic variation in TP53 may also contribute to the risk of developing glioma.

Methods:

To comprehensively evaluate the impact of variation in TP53 on risk, we analysed 23 tagSNPs and imputed 2377 unobserved genotypes in four series totaling 4147 glioma cases and 7435 controls.

Results:

The strongest validated association signal was shown by the imputed single-nucleotide polymorphism (SNP) rs78378222 (P=6.86 × 10⁻²⁴, minor allele frequency ∼0.013). Confirmatory genotyping confirmed the high quality of the imputation. The association between rs78378222 and risk was seen for both glioblastoma multiforme (GBM) and non-GBM tumours. We comprehensively examined the relationship between rs78378222 and overall survival in two of the case series totaling 1699 individuals. Despite employing statistical tests sensitive to the detection of differences in early survival, no association was shown.

Conclusion:

Our data provided strong validation of rs78378222 as a risk factor for glioma but do not support the tenet that the polymorphism being a clinically useful prognostic marker. Acquired TP53 inactivation is a common feature of glioma. As rs78378222 changes the polyadenylation signal of TP53 leading to impaired 3′-end processing of TP53 mRNA, the SNP has strong plausibility for being directly functional contributing to the aetiological basis of glioma.

Analysis of 60 reported glioma risk SNPs replicates published GWAS findings but fails to replicate associations from published candidate-gene studies

Genomewide association studies (GWAS) and candidate-gene studies have implicated single-nucleotide polymorphisms (SNPs) in at least 45 different genes as putative glioma risk factors. Attempts to validate these associations have yielded variable results and few genetic risk factors have been consistently replicated. We conducted a case-control study of Caucasian glioma cases and controls from the University of California San Francisco (810 cases, 512 controls) and the Mayo Clinic (852 cases, 789 controls) in an attempt to replicate previously reported genetic risk factors for glioma. Sixty SNPs selected from the literature (eight from GWAS and 52 from candidate-gene studies) were successfully genotyped on an Illumina custom genotyping panel. Eight SNPs in/near seven different genes (TERT, EGFR, CCDC26, CDKN2A, PHLDB1, RTEL1, TP53) were significantly associated with glioma risk in the combined dataset (P < 0.05), with all associations in the same direction as in previous reports. Several SNP associations showed considerable differences across histologic subtype. All eight successfully replicated associations were first identified by GWAS, although none of the putative risk SNPs from candidate-gene studies was associated in the full case-control sample (all P values > 0.05). Although several confirmed associations are located near genes long known to be involved in gliomagenesis (e.g., EGFR, CDKN2A, TP53), these associations were first discovered by the GWAS approach and are in noncoding regions. These results highlight that the deficiencies of the candidate-gene approach lay in selecting both appropriate genes and relevant SNPs within these genes.

Association of p53 Arg72Pro and MDM2 SNP309 polymorphisms with glioma

Epidemiological studies of the association of variants p53 Arg72Pro and MDM2 single-nucleotide polymorphism 309 (SNP309) with glioma risk have produced inconsistent results. The aim of the current study was to evaluate the association of these 2 variants with glioma susceptibility using a meta-analysis approach. For p53 Arg72Pro, 10 case-control studies including 2587 glioma patients and 4061 unrelated controls were identified. The pooled odds ratios (ORs) for Arg/Pro heterozygotes and Pro/Pro homozygotes were 1.08 [95% confidence interval (95%CI) = 0.85-1.37] and 1.08 (95%CI = 0.85-1.36), respectively, when compared to Arg/Arg carriers. Under the dominant effect model, Pro allele carriers also showed no significantly elevated glioma risk (pooled OR = 1.11, 95%CI = 0.90-1.38), and similar results were found under the recessive-effect model (pooled OR = 1.17, 95%CI = 0.85-1.61). For variant MDM2 SNP309, 3 case-control studies including 606 cases and 309 controls were identified. A marginal association with glioma risk was found for heterozygous G/T carriers (pooled OR = 1.95, 95%CI = 1.00- 3.81), whereas homozygous G/G carriers showed an increased but not significantly elevated risk of glioma (pooled OR = 2.14, 95%CI = 0.71-6.45) compared with that of T/T homozygotes. We also found no significant association between the MDM2 SNP309 polymorphism and glioma risk (pooled OR = 1.86, 95%CI = 0.94-3.67 and pooled OR = 1.25, 95%CI = 0.62-2.56, respectively) under the dominant and recessive models. Taken together, the current data suggested that the 2 polymorphisms may not contribute to glioma susceptibility.

The association of osteopontin and LMX1A expression with World Health Organization grade in meningiomas and gliomas

AIMS

Osteopontin (OPN) and LIM homeobox transcription factor 1, alpha (LMX1A) are important factors related to tumour progression, invasion and metastasis in human cancers. The aim of this study was to test the hypothesis that expression of OPN and of LMX1A correlate with the World Health Organization (WHO) grading system of primary brain tumours.

METHODS AND RESULTS

Immunohistochemical analyses of OPN and LMX1A expression were performed in 139 cases of brain tumour, including 65 meningiomas, 71 gliomas, and three central neurocytomas. More than 90% of WHO grade I meningiomas showed negative or weak staining for OPN and LMX1A. However, among all WHO grade II and III meningiomas, 100% and 66.7% showed moderate or strong staining for OPN and LMX1A, respectively. Similarly, higher percentages of WHO grade I and II gliomas than of WHO grade III and IV gliomas showed negative or weak staining for OPN. A higher intensity of immunoreactivity for LMX1A correlated with more advanced grade in WHO grade I-III gliomas, but not in WHO grade IV tumours.

CONCLUSIONS

Higher immunostaining intensity for OPN and LMX1A correlated with WHO grades for meningiomas and some gliomas. Contrary to our expectations, LMX1A staining in WHO grade IV gliomas was shown to be weaker than in WHO grade III tumours.

Selected polymorphisms of GSTP1 and TERT were associated with glioma risk in Han Chinese

BACKGROUND

Current evidence suggests that a majority of the inherited risks play a major role in glioma susceptibility, and glioma is due to the co-inheritance of multiple low-risk variants. These variants can be identified through association studies including such as genome-wide association studies (GWAS), which has led the glioma epidemiology researchers to focus on identifying potential disease-causing factors.

METHODS

We evaluated and validated 10 tag single nucleotide polymorphisms (tSNPs) in seven genes associated with glioma susceptibility in a Han Chinese population, including 301 glioma cases and 302 controls, using a multiplexed single nucleotide polymorphism (SNP) MassEXTEND assay. We ascertained the genotypic frequencies for each tSNP in control subjects were within Hardy-Weinberg equilibrium (HWE) using an exact test, and then compared the genotype and allele frequencies of glioma patients and control subjects using the χ2 test. We then applied three genetic models (dominant, recessive, and additive) using PLINK software to assess the association of each tSNP with glioma risk.

RESULTS

We identified two tSNPs to be associated with glioma susceptibility (rs1695, GSTP1, P = 0.019; rs2853676, TERT, P = 0.039), which we confirmed using dominant and additive model analyses. The genotype &ldquo;GA&rdquo; for rs1695 was recognized to be a protective genotype for glioma (OR, 0.67; 95% CI, 0.47-0.96; P = 0.027), while the genotype &ldquo;AG&rdquo; for rs2853676 was shown to be a risk genotype for glioma (OR, 1.50; 95% CI, 1.05-2.15; P = 0.025).

CONCLUSION

Our results, and those from previous studies, suggest potential genetic contributes for GSTP1 and TERT in glioma development.

Association between p21 Ser31Arg polymorphism and cancer risk: a meta-analysis

P21 (CDKN1A), a key cell cycle regulatory protein that governs cell cycle progression from G1 to S phase, can regulate cell proliferation, growth arrest, and apoptosis. The Ser31Arg polymorphism is located in the highly conserved region of p21 and may encode functionally distinct proteins. Although many epidemiological studies have been conducted to evaluate the association between the p21 Ser31Arg polymorphism and cancer risk, the findings remain conflicting. This meta-analysis with 33 077 cases and 45 013 controls from 44 published case-control studies showed that the variant homozygous 31Arg/Arg genotype was associated with an increased risk of numerous types of cancers in a random-effect model (homozygote comparison: OR = 1.17, 95% CI = 0.99 to 1.37, P = 0.0002 for the heterogeneity test; recessive model comparison: OR = 1.16, 95% CI = 1.01 to 1.33, P = 0.0001 for the heterogeneity test). Stratified analysis revealed that increased cancer risk associated with the 31Arg/Arg genotype remained significant in subgroups of colorectal cancer, estrogen-related cancer, Caucasians, population-based studies, studies with matching information or a larger sample size. Heterogeneity analysis showed that tumor type contributed to substantial between-study heterogeneity (recessive model comparison: Χ(2) = 21.83, df = 7, P = 0.003). The results from this large-sample sized meta-analysis suggest that the p21 31Arg/Arg genotype may serve as a potential marker for increased cancer risk.

Association of CASP3 polymorphism with hematologic toxicity in patients with advanced non-small-cell lung carcinoma treated with platinum-based chemotherapy

Apoptosis is a distinct mode of cell death that is responsible for the deletion of cells in tumors and in normal tissues. We pursued a pathway-based approach to investigate the association of potentially functional genetic polymorphisms of the corresponding genes with the outcomes of platinum-based chemotherapy in advanced non-small-cell lung cancer (NSCLC). A MALDI-TOF mass spectrometer was used for genotyping 10 polymorphisms of eight apoptosis-related genes, including BCL2 rs1801018, rs1564483, rs2279115, BAX rs4645878, caspase (CASP3) rs6948, CASP8 rs3834129, CASP10 rs13006529, rs3900115, tumor necrosis factor α (TNFα) rs1800629, and macrophage migration inhibitory factor (MIF) rs755622. The associations between these single nucleotide polymorphisms and the outcomes of 445 advanced NSCLC patients treated with platinum-based chemotherapy were evaluated. The CASP3 rs6948 polymorphism was most significantly associated with hematologic toxicity in a dose-dependent manner. The incidence of severe hematologic toxicity was significantly lower in C allele carriers (P = 0.005; odds ratio = 0.524; 95% confidence interval = 0.333-0.824) and still significant after a Bonferroni correction. The function of this single nucleotide polymorphism in gene expression was also investigated. Quantitative PCR showed that individuals with the C allele had lower levels of CASP3 transcripts in peripheral blood lymphocytes. Luciferase reporter assays showed that the minor C allele significantly decreased the reporter gene expression level. In addition, the TNFα rs1800629 mutant allele significantly elevated gastrointestinal toxicity (P = 0.020; odds ratio = 3.020; 95% confidence interval = 1.188-7.676), when compared to the wild-type homozygote. No other association was found. In conclusion, for the first time, our study suggests that CASP3 rs6948 might influence CASP3 expression and be associated with severe hematologic toxicity risk.

Genetic variant in CASP3 affects promoter activity and risk of esophageal squamous cell carcinoma

Caspase-3 (CASP3) is the main executioner of apoptosis, mediating both extrinsic and intrinsic cell death signaling pathways, and is involved in tumor behaviors. In this study, we investigated the association of two regulatory variants in CASP3 and the risk of esophageal squamous cell carcinoma (ESCC) in 1026 cases and 1270 healthy controls. Odds ratios (OR) and 95% confidence intervals (CI) were computed by logistic regression. The function of the CASP3 829 A>C polymorphism was examined by luciferase reporter assay and real-time PCR. A significant increased risk of ESCC was found for the CASP3 829 AC and CC genotypes with OR (95% CI), 1.53 (1.26-1.89) and 1.42 (1.11-1.82), respectively. When stratified by age and gender, the risk of ESCC was more significant in younger (≤57 years) and male individuals. No significantly changed risk of ESCC was related to 20541 C>T variant. Luciferase reporter assay showed 829 A>C variant dramatically reduced the transcriptional activity of luciferase reporter gene by over 95% in both KYSE30 and KYSE450 esophageal cancer cells. Remarkably, the transcriptional activity of the 829C-containing construct was much lower than the activity of the pGL3-basic construct, with over 85% reduction in both cell lines. Real-time PCR analyses showed that 829 AA genotype carriers had significantly higher RNA levels (0.015 ± 0.00216, n = 24) than the 829 AC genotype carriers (0.00969 ± 0.00136, n = 36), and 829 CC genotype carriers (0.00663 ± 0.00097, n = 20). These findings suggest that CASP3 829 A>C polymorphism may highly affect the function of caspase-3 and play an important role in the development of ESCC in Chinese populations.