• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.299-304
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• 2014

Cholangiocarcinoma (CCA), a malignancy of biliary duct with a very poor prognosis, is the leading cause of cancer death in countries of the Mekong subregion. Liver fluke infection is the main etiological factor, but genetic variation has been recognized as also important in conferring susceptibility to CCA risk. Nuclear factor (erythroid derived 2)-like 2 (NRF2) is a key transcription factor in detoxification and antioxidant defense. Emerging evidence has demonstrated that genetic polymorphisms in the NRF2 gene may be associated with cancer development. The objectives of this study were to investigate the association of NRF2 genetic polymorphism with CCA risk and to evaluate the influence of the NRF2 genotype on survival time of affected patients. Single nucleotide polymorphisms (SNPs) of the NRF2 gene, including rs6726395: A/G, rs2886161: C/T, rs1806649: C/T, and rs10183914: C/T, were analyzed using TaqMan$^{(R)}$ SNP genotyping assays. Among 158 healthy northeastern Thai subjects, the allele frequencies were 41, 62, 94, and 92%, respectively. The correlation of NRF2 SNPs and CCA risk was analyzed in the 158 healthy subjects and 198 CCA patients, using unconditional logistic regression. The results showed that whereas the NRF2 SNPs were not associated with CCA risk (p>0.05), Kaplan-Meier analysis of 88 intrahepatic CCA patients showed median survival time with rs6726395 genotypes of GG and AA/AG to be $344{\pm}138$ (95%CI: 73-615) days and $172{\pm}37$ (95%CI: 100-244) days, respectively, (p<0.006). On multivariate Cox proportional hazard analysis, the GG genotype of rs6726395 was found to be associated with longer survival with a hazard ratio of 0.54 (95%CI: 0.31-0.94). In addition, non-papillary adenocarcinoma was associated with poor survival with a hazard ratio of 2.09 (95%CI: 1.16-3.75). The results suggest that the NRF2 rs6726395 polymorphism can be a potential prognostic biomarker for CCA patients.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1599-1603
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• 2012

Objectives: Since methylenetetrahydrofolate reductase (MTHFR) maintains the balance of circulating folate and methionine and blocks the formation of homocysteine, its regulation in relation to different cancers has extensively been studied in different populations. However, information on Pakistani breast cancer patients is lacking. The MTHFR gene has two most common mutations that are single nucleotide additions which result in change of amino acids C677T to Ala222val and A1298C to Glu429Ala. Methodology: 110 sporadic breast patients with no prior family history of cancer or any other type of genetic disorders along with 110 normal individuals were screened for mutations in exons 1 to exon 9 using single strand conformational polymorphism, RFLP and sequencing analyzer. Results: The p values for the 677CC, 677CT, and 677TT genotypes were 0.223, 0.006, and 0.077, respectively. Those for the 1298AA, 1298AC, and 1298CC genotypes were 0.555, 0.009, and 0.003, respectively. Conclusions: We found an overall a significant, weak inverse association between breast cancer risk and the 677TT genotype and an inverse association with the 1298C variant. These results for MTHFR polymorphism might be population specific in sporadic breast cancer affected patients but many other factors need to be excluded before making final conclusions including folate intake, population and disease heterogeneity.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.5069-5073
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• 2015

The single nucleotide polymorphism (SNP) rs1053004 in Signal transducer and activator of transcription 3 (STAT3) was recently reported to be associated with chronic hepatitis B (CHB)-related hepatocellular carcinoma (HCC) in a Chinese cohort. This study was aimed at investigating whether the SNP might also contribute to HCC susceptibility in the Thai population. Study subjects were enrolled and divided into 3 groups including CHB-related HCC (n=211), CHB without HCC (n=233) and healthy controls (n=206). The SNP was genotyped using allelic discrimination assays based on TaqMan real-time PCR. Data analysis revealed that the distribution of different genotypes was in Hardy-Weinberg equilibrium (P>0.05). The frequencies of allele T (major allele) in HCC patients, CHB patients and healthy controls were 51.4%, 58.6% and 61.4%, respectively, whereas the frequencies of C allele (minor allele) were 48.6%, 41.4% and 38.6%. The C allele frequency was higher in HCC when compared with CHB patients (odds ratio (OR)=1.34, 95% confidence interval (CI)=1.02-1.74, P=0.032). The genotype of SNP rs1053004 (CC versus TT+TC) was significantly associated with an increased risk when compared with CHB patients (OR=1.83, 95% CI=1.13-2.99, P=0.015). In addition, we observed a similar trend of association when comparing HCC patients with healthy controls (OR=1.77, 95% CI=1.07-2.93, P=0.025) and all controls (OR=1.81, 95% CI=1.19-2.74, P=0.005). These findings suggest that the SNP rs1053004 in STAT3 might contribute to HCC susceptibility and could be used as a genetic marker for HCC in the Thai population.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5311-5316
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• 2013

A functional polymorphism in the NQO1 gene, featuring a 609C>T substitution,leading to proline to serine amino-acid and enzyme activity changes, has been implicated in cancer risk. However, individually published investigations showed inconclusive results, especially for leukemia. In this study, we therefore performed a meta-analysis of 21 publications with a total of 3,634 cases and 4,827controls, mainly for leukemia. We summarized the data on the association between the NQO1 609C>T polymorphism and risk of leukemia and performed subgroup analyses by ethnicity and leukemia type. We found that the variant TT homozygous genotype o was associated with a modestly increased risk of leukemia (TT versus CT/CC: OR=1.23, 95%CI=1.00-1.51, heterogeneity=0.76; $I^2$=0%). Following further stratified analyses, increased risk was only observed in subgroups of Caucasians. This meta-analysis suggests that the NQO1 609T allele is a high-penetrance risk factor for leukemia in Caucasians. The effect on leukemia may be modified by ethnicity and leukemia type, and the small sample sizes of the subgroup analyses suggest that further larger studies are needed.

• The Journal of Korean Medicine
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• v.26 no.1 s.61
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• pp.59-70
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• 2005

Objective: Tumor necrosis factor-a $(TNF-{\alpha})$, a potent immuno-modulator and pro-inflammatory cytokine, has been implicated in many pathological processes. In this study, the author examined whether promoter region polymorphism in the $TNF-{\alpha}$a gene at position-308 affect the odds of cerebral infarction (CI) and whether genetic risk is enhanced by sasang constitutional classification. Methods: 212 CI patients and 610 healthy controls were genotyped and determined according to sasang constitutional classification. The amplified genotypes were analyzed on $8\%$ polyacrylamide gel. The alleles were visualized by ethidium bromide staining. Primers for $TNF-{\alpha}$ were designed to incorporate a polymorphic site at a position -308 bp of the $TNF-{\alpha}$ gene into an NcoI restriction site. Restriction digests generated products of 87 and 20 bp for G allele and 107 bp for A allele. Results : A significant decrease was found for the $TNF-{\alpha}$ A allele in CI patients compared with controls (P=0.033, odds ratio, O.R.: 0.622). However, there was no significant association between $TNF-{\alpha}$ polymorphism and sasang constitution in CI patients. Conclusion: My finding suggests that $TNF-{\alpha}$promoter region polymorphism is responsible for susceptibility to CI in Koreans.

• Genomics & Informatics
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• v.8 no.4
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• pp.194-200
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• 2010

The PIK3CA gene, oncogenic gene located on human chromosome 3q26.3, is an important regulator of cell proliferation, death, motility and invasion. To evaluate the role of PIK3CA gene in the risk of Korean lung cancer, genotypes of the PIK3CA polymorphisms (rs11709323, rs2699895, rs3729679, rs17849074 and rs1356413) were determined in 423 lung cancer patients and 443 normal controls. Statistical analyses revealed that the genotypes and haplotypes in the PIK3CA gene were not significantly associated with the risk of lung cancer in the Korean population, suggesting that these PIK3CA polymorphisms do not contribute to the genetic susceptibility to lung cancer in the Korean population.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.16
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• pp.6715-6720
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• 2014

The purpose of this study was to evaluate associations of the CYP1A1 gene variant rs4646903 polymorphism with the risk of developing esophageal cancer (EC). A case-control study was carried out in Pashtun population of Khyber Pakhtunkhwa province of Pakistan in which 140 hospital based EC cases and 196 population based healthy controls exposed to similar environmental conditions were included. A specific method based on the real time polymerase chain reaction (RT-PCR) was used to detect genotypes in case and control groups and results were then analyzed with SPSS version 20. In our population, individuals with CC and TC genotypes of the CYP1A1 rs4646903 polymorphism had significantly higher risk of EC (adjusted odds (OR): 15.709, 95%CI: 6.065-40.686, OR: 3.256 95%CI: 1.902-5.574 respectively). The 'C' allele was strongly associated with the disease (p< 0.0001). Adjusted OR was higher (1.5 times in C/C) in case of variant alleles that show the contribution of environmental and nutritional factors towards the development of EC. Our findings suggest that presence of the 'C' allele of rs4646903 (T>C) may be one of the risk alleles for EC susceptibility in Pashtun population.

• The Journal of the Korea Contents Association
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• v.17 no.10
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• pp.289-299
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• 2017

To verify the association between susceptibility to chronic myeloid leukemia (CML) and GSTM1, GSTT1 gene polymorphisms in Asian populations, 9 papers published until July 2017 were cited in a meta-analysis. The null present types of the GSTM1, GSTT1 gene were analyzed individually. The significant association was found between CML and GST polymorphism (GSTM1; OR=1.306, 95% CI=1.091-1.563, p=0.004, GSTT1; OR=1.987, 95% CI=1.438-2.746, p=0.000). In addition, there was association between CML and the null type of the combination GSTM1-GSTT1 polymorphisms (OR=4.191, 95% CI=2.833-6.201, p=0.000). Thus, genetic polymorphisms of the GSTM1, GSTT1 and combination GSTM1-GSTT1 polymorphism in Asian populations may be risk factors for CML.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.287-290
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• 2014

Objective: Genetic variation is considered to strongly impact on detoxification of carcinogens and therefore is related to cancer risk. However, findings for the null genotypes of GSTT1 and GSTM1 have not always been consistent. Therefore the present meta-analysis was conducted. Methods: We accessed the reported study at different research areas and used various databases, including PubMed and Wanfang Med Onlion from 1990 to May 1st 2013. We calculated the odds ratio (OR), 95% confidence interval (CI) and P value for oral cancer by using Review Manager 5.1 and STATE 12. Results: We found that there was no increased oral cancer risk among subjects carrying GSTM1 and GSTT1 null genotype (OR=1.35, 95%CI=0.68-2.68, P=0.39) and (OR=1.41, 95%CI=0.72-2.77, P=0.31) in the Chinese population. In contrast, in studies in India a significant correlation between GSTM1 null genotype and oral cancer was observed (OR=1.59, 95%CI=1.20-2.11, P=0.001), but not in GSTT1 (OR=1.21, 95% CI=0.84-1.74, P=0.31). Conclusion: We discovered that GSTM1 deletion polymorphism had a significant effect on the susceptibility of oral cancer in the Indian population.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.3
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• pp.504-511
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• 2010

Diabetes is a disease that contains a high concentration of glucose in blood and due to defects in either insulin secretion or insulin action. Although the distinctive causes and factors of diabetes have not been clarified, the genetic factors are suggested as a main susceptibility until now. SNP (Single Nucleotide Polymorphism), as the most common genetic variation, has an influence on personal susceptibility for diseases. A nonsynonymous SNP, which changes the amino acid of the protein and its function, is especially important. Therefore, this study hypothesized that there are associations between specific SNPs of the targeted genes. Transcription factor 7-like 2 (TCF7L2) and fat mass and obesity associated (FTO) genes were selected as target genes from the results of genome-wide association and other related research studies. Second, four nonsynonymous SNPs (three in TCF7L2 and one in FTO gene) were selected as target SNPs by using public database of NCBI (National Center for Biotechnology Information). The recruited personnel was classified into three subgroups of diabetes, impaired fasting glucose (IFG) and normal groups. The individual genotypes of each group were analyzed by resequencing. None of genetic variations at four targeted SNP sites was revealed in all samples of this study. However, this study found two new SNPs that were not reported in TCF7L2 gene. One is synonymous SNP, which is heterozygous of C/T and no amino acid change of asparagine/asparagines, was located at c1641 and found in one normal person. Another is nonsynonymous SNP, which is heterozygous of G/A, was located at c1501 and found in two samples. This new discovered nonsynonymous SNP induce the amino acid change from alanine to threonine. Moreover, this new nonsynonymous SNP was found among two persons, one of whom was a diabetes patient and the other one was a person at boundary between IFG and normal, suggesting that this variant might be associated with IFG or diabetes. Even if there is a limitation of sample number for statistical power, this study has an importance due to the discovery of new SNPs. In the future study, a large sample number of diabetes cohort will be needed to investigate the frequency and association with new discovered SNP.