RORA gene rs12912233 and rs880626 polymorphisms and their interaction with SCN1A rs3812718 in the risk of epilepsy: a case-control study in Malaysia.

RAR-related orphan receptors A (RORA) and B (RORB) and voltage-gated sodium channel type 1 (SCN1A) genes play critical roles in the regulation of the circadian clock. Evidence has shown an association of RORA and RORB polymorphisms with susceptibility to autism and depression. Hence, we tested the association of RORA rs12912233, rs16943429, rs880626, rs2290430, and rs12900948; RORB rs1157358, rs7022435, rs3750420, and rs3903529; and SCN1A rs3812718 with epilepsy risk in the Malaysians. DNA was genotyped in 1789 subjects (39% epilepsy patients) by using MassARRAY (Sequenom). Significant association was obtained for rs12912233 in Malaysian Chinese (p=0.003). Interaction between rs12912233-rs880626 and rs3812718 was associated with the epilepsy risk in the subjects overall (p=0.001). Results show that RORA rs12912233 alone might be a possible risk variant for epilepsy in Malaysian Chinese, but that, together with RORA rs880626 and SCN1A rs3812718, this polymorphism may have a synergistic effect in the epilepsy risk in Malaysians.

Case-control association study of polymorphisms in the voltage-gated sodium channel genes SCN1A, SCN2A, SCN3A, SCN1B, and SCN2B and epilepsy.

High-frequency action potentials are mediated by voltage-gated sodium channels, composed of one large α subunit and two small ß subunits, encoded mainly by SCN1A, SCN2A, SCN3A, SCN1B, and SCN2B genes in the brain. These play a key role in epilepsy, with the most commonly mutated gene in epilepsy being SCN1A. We examined whether polymorphisms in the above genes affect epilepsy risk in 1,529 epilepsy patients and 1,935 controls from four ethnicities or locations: Malay, Indian, and Chinese, all from Malaysia, and Chinese from Hong Kong. Of patients, 19 % were idiopathic, 42 % symptomatic, and 40 % cryptogenic. We genotyped 43 polymorphisms: 27 in Hong Kong, 28 in Malaysia, and 12 in both locations. The strongest association with epilepsy was rs3812718, or SCN1A IVS5N+5G>A: odds ratio (OR) = 0.85 for allele G (p = 0.0009) and 0.73 for genotype GG versus AA (p = 0.003). The OR was between 0.76 and 0.87 for all ethnicities. Meta-analysis confirmed the association (OR = 0.81 and p = 0.002 for G, and OR = 0.67 and p = 0.007 for GG versus AA), which appeared particularly strong for Indians and for febrile seizures. Allele G affects splicing and speeds recovery from inactivation. Since SCN1A is preferentially expressed in inhibitory neurons, G may decrease epilepsy risk. SCN1A rs10188577 displayed OR = 1.20 for allele C (p = 0.003); SCN2A rs12467383 had OR = 1.16 for allele A (p = 0.01), and displayed linkage disequilibrium with rs2082366 (r (2) = 0.67), whose genotypes tended toward association with SCN2A brain expression (p = 0.10). SCN1A rs2298771 was associated in Indians (OR = 0.56, p = 0.005) and SCN2B rs602594 with idiopathic epilepsy (OR = 0.62, p = 0.002). Therefore, sodium channel polymorphisms are associated with epilepsy.

Polymorphisms in methylenetetrahydrofolate reductase gene and risk of non-Hodgkin lymphoma in a multi-ethnic population.

An imbalance in folate metabolism can adversely affect DNA synthesis and methylation systems which can lead to susceptibility to non-Hodgkin lymphoma (NHL). Whether single nucleotide polymorphisms (SNPs) and their haplotypes in the methylenetetrahydrofolate reductase (MTHFR) are associated with NHL, remain inconclusive. We investigated the association between MTHFR C677T and A1298C SNPs and NHL risk in a population which is made up of Malay, Chinese and Indian ethnic subgroups. A total of 372 NHL patients and 722 controls were genotyped using the Sequenom MassARRAY platform. Our results of the pooled subjects failed to demonstrate significant association between the MTHFR C677T and A1298C SNPs with NHL and its subtypes. The results were in agreement with the previous meta-analyses. In the Indian ethnic subgroup however, single locus analysis of MTHFR A1298C appears to confer risk to NHL (Odds ratio (OR) 1.91, 95% confidence interval (95% CI) 1.22-3.00, P=0.006). The risk is almost doubled in homozygous carrier of MTHFR 1298CC (OR 4.03, 95% CI 1.56-10.43, P=0.004). Haplotype analysis revealed higher frequency of CC in the Indian NHL patients compared with controls (OR 1.86, 95% CI 1.18-2.93, P=0.007). There is lack of evidence to suggest an association between MTHFR C677T and A1298C with the risk of NHL in the Malays and Chinese. In the Indians however, the MTHFR A1298C confers risk to NHL. This study suggests ethnicity modifies the relationship between polymorphisms in the folate-metabolizing gene and NHL.

Lack of association between synapsin II (SYN2) gene polymorphism and susceptibility epilepsy: a case-control study and meta-analysis.

OBJECTIVE: The SYN2 rs3773364 A>G polymorphism has been proposed to be involved in susceptibility to epilepsy, but research results have been inconclusive. The aim of this study was to investigate the association between the SYN2 rs3773364 A>G polymorphism and susceptibility against epilepsy in a case-control study and a meta-analysis. METHODS: The SYN2 rs3773364 A>G polymorphism was successfully genotyped in 1182 samples (618 epilepsy patients) of Chinese, Indian, and Malay ethnicities. Meta-analysis of the related studies, including this case-control study, was performed under alternative genetic models. RESULTS: Data from the case-control study indicated no allelic and genotypic association of this locus with susceptibility to epilepsy in the tri-ethnic Malaysian population. Similar finding was obtained by stratified analysis by epilepsy syndrome for idiopathic epilepsy. These results were verified by meta-analysis of the related pooled data. CONCLUSIONS: Our study indicated that SYN2 rs3773364 A>G polymorphism is not a risk factor for susceptibility to epilepsy.

Association of 8q24.21 loci with the risk of colorectal cancer: a systematic review and meta-analysis.

BACKGROUND AND AIM: Recent genome-wide association studies of colorectal cancer (CRC) have identified rs6983267 and trs10505477 polymorphisms as key loci in the 8q24 region to be associated with CRC. In the present study, we performed a meta-analysis to determine whether these loci are risk factors for susceptibility to CRC. METHODS: We meta-analyzed the 22 included studies (47 003 cases and 45 754 controls) that evaluated the association of rs6983267 and trs10505477 with CRC under alternative genetic models. RESULTS: A meta-analysis of the pooled data showed allelic and genotypic association of the rs6983267 polymorphism with CRC risk in Asians, Europeans, and European-Americans. A subanalysis of the US studies showed negative results in the studies with non-identified ethnicity of the patients. A meta-analysis of included studies of rs10505477 polymorphisms identified allelic and genotypic associations with CRC risk in the US patients. A further meta-analysis of the US studies demonstrated positive results in the studies with non-identified ethnicity of the samples. CONCLUSION: Our data suggested that the rs6983267 G > T polymorphism is a risk factor for CRC in Asians, Europeans, and Americans with European ancestry.

Association between ABCB1 polymorphism and response to sodium valproate treatment in Malaysian epilepsy patients.

Over-expression of P-glycoprotein, encoded by the ABCB1 gene, is proposed to be involved in resistance to antiepileptic drugs in about 30% of patients with epilepsy. Here, we investigated the possible association between ABCB1 polymorphisms and sodium valproate (VPA) treatment in Malaysian epilepsy patients. Genotypes were assessed in 249 drug-resistant and 256 drug-responsive Malaysian patients for C1236T, G2677T/A, and C 5T polymorphisms in the ABCB1 gene. No genotypes, alleles, or haplotypes were associated with the response to VPA in either the overall group or Chinese, Indian, and Malay subgroups. Our data suggest that C1236T, G2677T/A, and C3435T polymorphisms in the ABCB1 gene do not contribute to the response to VPA in patients with epilepsy.

MIR196A2 rs11614913 contributes to susceptibility to colorectal cancer in Iranian population: A multi-center case-control study and meta-analysis.

Maturation of MIR196A2 as a gene regulator with a high potential for targeted cancer therapy can be modulated by the rs11614913 polymorphism. Several studies evaluating the association between this variant and pathogenesis of colorectal cancer (CRC) found significant results in various ethnic groups. This study aimed at investigating this relationship in a large sample size of Iranians as well as in a systematic review and meta-analysis of the pooled data of the current study with previous reports from Iran and other populations. After extraction of genomic DNA from the formalin-fixed paraffin-embedded tissues and whole blood of 2150 subjects (42% CRC patients), the rs11614913 was genotyped in both cases and controls. Furthermore, we conducted a meta-analysis of the present case-control study together with a previous report from Iranian population. The results of case-control study identified significant association between the rs11614913 and susceptibility to CRC [TT vs. CC: 1.58 (1.26-1.98), p < 0.01; TT vs. CT: 3.94 (3.07-5.05), p < 0.01; TT vs. CC + CT: 0.70 (0.59-0.83), p < 0.01; and CT + TT vs. CC: 1.43 (1.21-1.70), p < 0.01]. After correction of the meta-analysis results by using Bonferroni protocol, no significant association was observed in overall and in Asians [T vs. C: 1.19 (1.00-1.43), p = 0.05 and 1.14 (0.83-1.56), p = 0.43, respectively], whereas association was significant in Caucasians [T vs. C: 1.14 (1.04-1.25), p = 0.004] influenced by the data from Iran [T vs. C: 1.15 (1.03-1.29), p = 0.02 and TT vs. CC + CT: 0.73 (0.60-0.87), p = 0.003]. In conclusion, MIR196A2 rs11614913 might play a potential role in the pathogenesis of CRC in Iranian population.

MTRR rs1801394 and its interaction with MTHFR rs1801133 in colorectal cancer: a case-control study and meta-analysis.

AIM: This study aims to evaluate the association between the MTRR rs1801394 alone or in interaction with the MTHFR rs1801133 and susceptibility to colorectal cancer (CRC) and its characteristics in Iranian population. Additionally, both a systematic review and meta-analysis were performed to derive a more precise assessment of this association. MATERIALS & METHODS: Genomic DNA of 2332 subjects was genotyped for rs1801394. These data were pooled with 17 eligible studies for meta-analysis. RESULTS: No significant association was found between the rs1801394 or rs1801394-rs1801133 and CRC risk. Meta-analysis results also demonstrated no significant relationship between the rs1801394 and CRC risk. CONCLUSION: Results of this study showed that the rs1801394 alone or together with the rs1801133 is not a risk factor for CRC in Iranian population.

Lack of association of CASC8 rs1447295 with colorectal cancer in Iranian population: A multicenter case-control study.

Several studies reported the potential role of the rs1447295 polymorphism in susceptibility to cancer. This variant located in the cancer susceptibility candidate 8 (CASC8) is a long noncoding RNA (lnRNA) gene and does not code protein. LnRNA transcripts play a potential regulatory role in the expression of key genes involved in multiple cellular pathways, including cell cycle, pluripotency, and immune response. The aim of this study is to evaluate this association with colorectal cancer (CRC) in a large case-control study of the Iranian population. After extraction of genomic DNA by the standard protocols, the rs1447295 was genotyped in 2416 subjects (46% patients). Results of this case-control demonstrated no significant association between the rs1447295 polymorphism and risk of CRC or its characteristics under allele or alternative genotype models. In conclusion, it is unlikely that the rs1447295 polymorphism is a risk variant for the development of CRC in Iranian population.

Mechanism of action of novel piperazine containing a toxicant against human liver cancer cells.

The purpose of this study was to assess the cytotoxic potential of a novel piperazine derivative (PCC) against human liver cancer cells. SNU-475 and 423 human liver cancer cell lines were used to determine the IC50 of PCC using the standard MTT assay. PCC displayed a strong suppressive effect on liver cancer cells with an IC50 value of 6.98 ± 0.11 µM and 7.76 ± 0.45 µM against SNU-475 and SNU-423 respectively after 24 h of treatment. Significant dipping in the mitochondrial membrane potential and elevation in the released of cytochrome c from the mitochondria indicated the induction of the intrinsic apoptosis pathway by PCC. Activation of this pathway was further evidenced by significant activation of caspase 3/7 and 9. PCC was also shown to activate the extrinsic pathways of apoptosis via activation of caspase-8 which is linked to the suppression of NF-κB translocation to the nucleus. Cell cycle arrest in the G1 phase was confirmed by flow cytometry and up-regulation of glutathione reductase expression was quantified by qPCR. Results of this study suggest that PCC is a potent anti-cancer agent inducing both intrinsic and extrinsic pathways of apoptosis in liver cancer cell lines.

35Year Research History of Cytotoxicity and Cancer: a Quantitative and Qualitative Analysis.

Cancer is the leading cause of morbidity and mortality worldwide, characterized by irregular cell growth. Cytotoxicity or killing tumor cells that divide rapidly is the basic function of chemotherapeutic drugs. However, these agents can damage normal dividing cells, leading to adverse effects in the body. In view of great advances in cancer therapy, which are increasingly reported each year, we quantitatively and qualitatively evaluated the papers published between 1981 and December 2015, with a closer look at the highly cited papers (HCPs), for a better understanding of literature related to cytotoxicity in cancer therapy. Online documents in the Web of Science (WOS) database were analyzed based on the publication year, the number of times they were cited, research area, source, language, document type, countries, organizationenhanced and funding agencies. A total of 3,473 publications relevant to the target key words were found in the WOS database over 35 years and 86% of them (n=2,993) were published between 20002015. These papers had been cited 54,330 times without self citation from 1981 to 2015. Of the 3,473 publications, 17 (3,557citations) were the most frequently cited ones between 2005 and 2015. The topmost HCP was about generating a comprehensive preclinical database (CCLE) with 825 (23.2%) citations. One third of the remaining HCPs had focused on drug discovery through improving conventional therapeutic agents such as metformin and ginseng. Another 33% of the HCPs concerned engineered nanoparticles (NPs) such as polyamidoamine (PAMAM) dendritic polymers, PTX/SPIOloaded PLGAs and cell derived NPs to increase drug effectiveness and decrease drug toxicity in cancer therapy. The remaining HCPs reported novel factors such as miR205, Nrf2 and p27 suggesting their interference with development of cancer in targeted cancer therapy. In conclusion, analysis of 35year publications and HCPs on cytotoxicity in cancer in the present report provides opportunities for a better understanding the extent of topics published and may help future research in this area.

Novel piperazine core compound induces death in human liver cancer cells: possible pharmacological properties.

The current study evaluates the cytotoxic mechanism of a novel piperazine derivate designated as PCC against human liver cancer cells. In this context, human liver cancer cell lines, SNU-475 and 243, human monocyte/macrophage cell line, CRL-9855, and human B lymphocyte cell line, CCL-156, were used to determine the IC50 of PCC using the standard MTT assay. PCC displayed a strong suppressive effect on SNU-475 and SNU-423 cells with an IC50 value of 6.98 ± 0.11 µg/ml and 7.76 ± 0.45 µg/ml respectively, after 24 h of treatment. Significant dipping in the mitochondrial membrane potential and elevation in the released of cytochrome c from the mitochondria indicated the induction of the intrinsic apoptosis pathway by PCC. Activation of this pathway was further evidenced by significant activation of caspase 3/7 and 9. PCC was also shown to activate the extrinsic pathways of apoptosis via activation of caspase-8 which is linked to the suppression of NF-ƙB translocation to the nucleus. Cell cycle arrest in the G1 phase was confirmed by flow cytometry and up-regulation of glutathione reductase expression was quantified by qPCR. This study suggests that PCC is a simultaneous inducer of intrinsic and extrinsic pathways of apoptosis in liver cancer cell lines.

MTHFR rs1801133 polymorphism and susceptibility to colorectal cancer in Iranian population: evidence of a case-control study and meta-analysis.

Several studies have investigated whether MTHFR rs1801133 polymorphism contributes to risk of colorectal cancer (CRC), however the results are inconclusive. AIM: The purpose of this study was to investigate this hypothesis in a case-control study and meta-analysis in Iranian population. MATERIALS & METHODS: This polymorphism was genotyped in the 2421 subjects (46% CRC patients) from Tehran. Meta-analysis was performed for determining the risk effect size of this polymorphism on CRC. RESULTS: Both case-control study and meta-analysis showed no association between rs1801133 and CRC risk or its features. CONCLUSION: This study failed to identify an association between the rs1801133 and susceptibility to CRC in Iranian population.

Association of BDNF Polymorphisms with the Risk of Epilepsy: a Multicenter Study.

Epilepsy is a common neurological disease characterized by recurrent unprovoked seizures. Evidence suggested that abnormal activity of brain-derived neurotrophic factor (BDNF) contributes to the pathogenesis of epilepsy. Some previous studies identified association between genetic variants of BDNF and risk of epilepsy. In this study, this association has been examined in the Hong Kong and Malaysian epilepsy cohorts. Genomic DNA of 6047 subjects (1640 patients with epilepsy and 4407 healthy individuals) was genotyped for rs6265, rs11030104, rs7103411, and rs7127507 polymorphisms by using Sequenom MassArray and Illumina HumanHap 610-Quad or 550-Duo BeadChip arrays techniques. Results showed significant association between rs6265 T, rs7103411 C, and rs7127507 T and cryptgenic epilepsy risk (p = 0.00003, p = 0.0002, and p = 0.002, respectively) or between rs6265 and rs7103411 and symptomatic epilepsy risk in Malaysian Indians (TT vs. CC, p = 0.004 and T vs. C, p = 0.0002, respectively) as well as between rs6265 T and risk of cryptogenic epilepsy in Malaysian Chinese (p = 0.005). The Trs6265-Crs7103411-Trs7127507 was significantly associated with cryptogenic epilepsy in Malaysian Indians (p = 0.00005). In conclusion, our results suggest that BDNF polymorphisms might contribute to the risk of epilepsy in Malaysian Indians and Chinese.

Contribution of GABRG2 Polymorphisms to Risk of Epilepsy and Febrile Seizure: a Multicenter Cohort Study and Meta-analysis.

Gamma-aminobutyric acid receptor (GABA-A) is the most common receptor of fast synaptic inhibition in the human brain. Gamma protein encoded by the GABRG2 gene is one of the subunits of the GABA-A receptor, which plays an essential role in the function of this receptor. Several studies have identified various febrile seizure (FS) and epilepsy risk variants of GABRG2 gene in different populations, but some others did not support these results. The aim of this case-control study is to investigate whether GABRG2 polymorphisms contribute to susceptibility for FS and epilepsy in pooled data of three cohorts, from Malaysia (composed of Malay, Chinese, and Indian), Hong Kong, and Korea. Furthermore, the pooled dataset of these cohorts with previous reports were meta-analyzed for determining the risk effect size of the rs211037 polymorphism on FS and symptomatic epilepsy (SE). The rs211037, rs210987, rs440218, rs2422106, rs211014, and rs401750 polymorphisms were genotyped in the 6442 subjects (1729 epilepsy and 4713 controls). Results of the case-control study showed associations between rs211037 and the risk of SE in the pooled data from all cohorts (T vs. C, p = 3 × 10(-5), and TT vs. CC, p = 2 × 10(-5)) and the risk of partial seizure in the combined data of Malaysia and Hong Kong (both T vs. C and TT vs. CC, p = 2 × 10(-6)). The rs211037-rs210987 and rs2422106-rs211014-rs401750 haplotypes were also associated with susceptibility to SE in Chinese. Meta-analysis of all Asians identified association between rs211037 and FS and SE (T vs. C, p = 4 × 10(-4), and p = 4 × 10(-3), respectively). In conclusion, rs211037 alone may be a risk factor for FS, partial seizure, and SE, and in linkage disequilibrium with rs210987 can contribute to FS and SE in Asians, particularly in Chinese.

Evaluation of association studies and meta-analyses of MTHFR gene polymorphisms in colorectal cancer.

There is a discrepancy between the results of 89 original studies and 15 meta-analyses investigating the association of MTHFR rs1801133 and rs1801131 polymorphisms with colorectal cancer (CRC) risk. We examined this hypothesis through meta-analyses of both loci and their diplotypes as well as evaluation of previous meta-analyses. The present meta-analysis showed that rs1801133 and rs1801131 might be CRC susceptibility variants in Americans and Australians and rs1801133 in Brazilians and Japanese. A strong linkage disequilibrium was observed between both loci and their diplotypes were associated with CRC risk. Evaluation of 15 meta-analyses showed a high discrepancy among their findings, mainly caused by population stratification of original studies and data analysis strategies in meta-analysis. Population stratification was more dominant in the studies from Australia, America and Brazil leading to false positive or negative results. In conclusion, these loci alone might modify the development of CRC in some ethnicities.

KCNJ11: Genetic Polymorphisms and Risk of Diabetes Mellitus.

Diabetes mellitus (DM) is a major worldwide health problem and its prevalence has been rapidly increasing in the last century. It is caused by defects in insulin secretion or insulin action or both, leading to hyperglycemia. Of the various types of DM, type 2 occurs most frequently. Multiple genes and their interactions are involved in the insulin secretion pathway. Insulin secretion is mediated through the ATP-sensitive potassium (KATP) channel in pancreatic beta cells. This channel is a heteromeric protein, composed of four inward-rectifier potassium ion channel (Kir6.2) tetramers, which form the pore of the KATP channel, as well as sulfonylurea receptor 1 subunits surrounding the pore. Kir6.2 is encoded by the potassium inwardly rectifying channel, subfamily J, member 11 (KCNJ11) gene, a member of the potassium channel genes. Numerous studies have reported the involvement of single nucleotide polymorphisms of the KCNJ11 gene and their interactions in the susceptibility to DM. This review discusses the current evidence for the contribution of common KCNJ11 genetic variants to the development of DM. Future studies should concentrate on understanding the exact role played by these risk variants in the development of DM.

Mechanism of Action of the Novel Nickel(II) Complex in Simultaneous Reactivation of the Apoptotic Signaling Networks Against Human Colon Cancer Cells.

The aim of this study was to evaluate the cytotoxic potential of a novel nickel(II) complex (NTC) against WiDr and HT-29 human colon cancer cells by determining the IC50 using the standard MTT assay. The NTC displayed a strong suppressive effect on colon cancer cells with an IC50 value of 6.07 ± 0.22 µM and 6.26 ± 0.13 µM against WiDr and HT-29 respectively, after 24 h of treatment. Substantial reduction in the mitochondrial membrane potential and increase in the release of cytochrome c from the mitochondria directed the induction of the intrinsic apoptosis pathway by the NTC. Activation of this pathway was further evidenced by significant activation of caspase 3/7 and 9. The NTC was also shown to activate the extrinsic pathway of apoptosis via activation of caspase-8 which is linked to the suppression of NF-κB translocation to the nucleus. Cell cycle arrest in the G1 phase was confirmed by flow cytometry and up-regulation of glutathione reductase expression was quantified by qPCR. Results of the current work indicates that NTC possess a potent cancer cell abolishing activity by simultaneous induction of intrinsic and extrinsic pathways of apoptosis in colon cancer cell lines.