Predictive value of ABCB1 polymorphisms G2677T/A, C3435T, and their haplotype in small cell lung cancer patients treated with chemotherapy

Purpose

Multiple drug resistance limits the efficacy of numerous cytotoxic drugs used in the treatment of small cell lung cancer (SCLC). The drug efflux protein ATP-binding cassette transporter B1 (ABCB1) has an important role in this process, and its gene variability may affect chemotherapy outcomes.

Patients and methods

This study aimed to evaluate the associations between ABCB1 polymorphisms G2677T/A, C3435T, and their haplotype with progression-free survival (PFS) and overall survival (OS) in 177 SCLC patients treated with cisplatin–etoposide or cyclophosphamide–epirubicin–vincristine chemotherapy. To determine the ABCB1 genotype, allelic specific TaqMan^? probes were used in a RT-PCR .

Results

Patients carrying the G2677T/A TT?+?TA?+?AA genotypes (24?%) or the C3435T CT?+?TT genotypes (72?%) or the 2677T/A-3435T haplotype (40?%) had a longer PFS (Cox regression, P?=?0.052, 0.037 and 0.037, respectively); these associations persisted also in multivariate analyses (Cox regression, P?=?0.028, 0.037 and 0.030, respectively). Moreover, patients with the C3435T CT?+?TT genotypes had a longer OS both in univariate and multivariate analysis (Cox regression, P?=?0.022 and 0.028, respectively). A trend toward longer OS was noted for the 2677T/A-3435T haplotype (Cox regression, P?=?0.051), but its independent value was not confirmed (Cox regression, P?=?0.071).

Conclusions

Our study reported a possible predictive value of ABCB1 polymorphisms G2677T/A, C3435T, and their haplotype for longer PFS and OS in Caucasian SCLC patients treated with chemotherapy. However, to be implemented into routine clinical practice, ABCB1 polymorphisms require further validation.     

Impact of ABCB1 Gene (C3435T/A2677G) Polymorphic Sequence Variations on the Outcome of Patients with Chronic Myeloid Leukemia and Acute Lymphoblastic Leukemia in Kashmiri Population: A Case–Control Study

Inherited polymorphic sequence variations in drug transport genes like ABCB1 impact a portion of patients with hematologic malignancies that show intrinsic or acquire resistance to treatment. Keeping in view inter-individual sensitivities for such drugs, we through this case–control study tested whether ABCB1 C3435T and G2677T polymorphisms have any influence on the risk and treatment response in patients with chronic myeloid leukemia (CML) and B-acute lymphoblastic leukemia (B-ALL). Genotyping for ABCB1 polymorphisms was performed by polymerase chain reaction-restriction fragment length polymorphism in 100 CML and 80 B-ALL patients along with 100 age and gender matched healthy controls. ABCB1 C3435T and G2677T polymorphism showed no association with CML. Genotype distribution revealed significant higher frequency of TT genotype for both SNPs in B-ALL cases and associated with increased B-ALL risk (OR 2.5, p = 0.04 for 3435TT; OR 2.4, p = 0.04 for 2677TT). There was no significant difference in genotype frequency of 3435C > T and 2677G > T among resistant and responsive groups for the two leukemia types. Kaplan–Meier survival plots revealed significantly lower event free survival in CML and B-ALL patients that were carriers of 3435TT genotype (p < 0.05). Multivariate analysis considered 3435TT genotype as independent risk factor for imatinib resistance in CML cases (HR 6.24, p = 0.002) and increased relapse risk in B-ALL patients (HR 4.51, p = 0.03). The current study provides preliminary evidence of a significant association between variant TT genotype and increased B-ALL risk. Also, results suggest that ABCB1 3435TT genotype increases imatinib resistance in CML and influence therapeutic outcome in B-ALL.     

Multidrug resistance gene (MDR1) polymorphisms are associated with major molecular responses to standard-dose imatinib in chronic myeloid leukemia

Despite the excellent efficacy of imatinib in chronic myeloid leukemia (CML), the response in patients is heterogeneous, which may in part be caused by pharmacogenetic variability. Imatinib has been reported to be a substrate of the P-glycoprotein pump. In the current study, we focused on the ABCB1 (MDR1) genotype. We analyzed the 3 most relevant single nucleotide polymorphisms of MDR1 in 90 CML patients treated with imatinib. Among the patients homozygous for allele 1236T, 85% achieved a major molecular response versus 47.7% for the other genotypes (P = .003). For the 2677G>T/A polymorphism, the presence of G allele was associated with worse response (77.8%, TT/TA; vs 47.1%, GG/GA/GT; P = .018). Patients with 1236TT genotype had higher imatinib concentrations. One of the haplotypes (1236C-2677G-3435C) was statistically linked to less frequent major molecular response (70% vs 44.6%; P = .021). Hence, we demonstrated the usefulness of these single nucleotide polymorphisms in the identification of CML who may or may not respond optimally to imatinib.     

Relationship between ABCB1 polymorphisms and serum methadone concentration in patients undergoing methadone maintenance therapy (MMT)

ABSTRACT

Background: Methadone is a substrate of the permeability glycoprotein (P-gp) efflux transporter, which is encoded by the ABCB1 (MDR1) gene. Large interindividual variability in serum methadone levels for therapeutic response has been reported. Genetic variations in ABCB1 gene may be responsible for the variability in observed methadone concentrations. Objective: This study investigated the associations of ABCB1 polymorphisms and serum methadone concentration over the 24-hour dosing interval in opioid-dependent patients on methadone maintenance therapy (MMT). Methods: One hundred and forty-eight male opioid-dependent patients receiving MMT were recruited. Genomic deoxyribonucleic acid (DNA) was extracted from whole blood and genotyped for ABCB1 polymorphisms [i.e. 1236C>T (dbSNP rs1128503), 2677G>T/A (dbSNP rs2032582), and 3435C>T (dbSNP rs1045642)] using the allelic discrimination real-time polymerase chain reaction (PCR). Blood samples were collected at 0, 0.5, 1, 2, 4, 8, 12, and 24 hours after the dose. Serum methadone concentrations were measured using the Methadone ELISA Kit. Results: Our results revealed an association of CGC/TTT diplotype (1236C>T, 2677G>T/A, and 3435C>T) with dose-adjusted serum methadone concentration over the 24-hour dosing interval. Patients with CGC/TTT diplotype had 32.9% higher dose-adjusted serum methadone concentration over the 24-hour dosing interval when compared with those without the diplotype [mean (SD) = 8.12 (0.84) and 6.11 (0.41) ng ml^?1 mg^?1, respectively; p = 0.033]. Conclusion: There was an association between the CGC/TTT diplotype of ABCB1 polymorphisms and serum methadone concentration over the 24-hour dosing interval among patients on MMT. Genotyping of ABCB1 among opioid-dependent patients on MMT may help individualize and optimize methadone substitution treatment.     

CYP2C19*2/ABCB1-C3435T polymorphism and risk of cardiovascular events in coronary artery disease patients on clopidogrel: Is clinical testing helpful?

BackgroundStudies evaluating CYP2C19*2 and ABCB1-C3435T polymorphisms have shown conflicting results. We performed this meta-analysis to evaluate role of clinical testing for these polymorphisms in CAD patients on clopidogrel.Methods19,601 patients from 14 trials were analyzed. The endpoints were major adverse cardiovascular events (MACE), cardiovascular (CV) death, stent thrombosis (ST), myocardial infarction (MI), stroke and major bleeding. Combined relative risks (RR) with 95% confidence intervals (CI) were computed for each outcome by using standard methods of meta-analysis and test parameters were computed.ResultsCYP2C19*2 polymorphism was associated with higher risk of MACE [RR: 1.28, CI: 1.06–1.54; p = 0.009], CV death [RR: 3.21, CI: 1.65–6.23; p = 0.001], MI [RR: 1.36, CI: 1.12–1.65; p = 0.002], ST [RR: 2.41, CI: 1.69–3.41; p < 0.001]. No difference was seen in major bleeding events [RR: 1.02, CI: 0.86–1.20; p = 0.83]. Subgroup analysis showed similar results for elective PCI [RR: 1.34, CI: 1.01–1.76; p = 0.03], and PCI with DES [RR: 1.53, CI: 1.029–1.269; p = 0.03]. CYP2C19*2 polymorphism has very low sensitivity (28–58%), specificity (71–73%), positive predictive value (3–10%) but good negative predictive value (92–99%). ABCB1-C3435T polymorphism analysis revealed similar MACE [RR: 1.13, CI: 0.99–1.29; p = 0.06], ST [RR: 0.88, CI: 0.52–1.47; p = 0.63] and major bleeding [RR: 1.04, CI: 0.87–1.25; p = 0.62] in both groups.ConclusionIn CAD patients on clopidogrel therapy, CYP2C19*2 polymorphism is associated with significantly increased adverse cardiovascular events. However, due to the low positive predictive value, routine genetic testing cannot be recommended at present.     

IL6, IL10 and TGFB1 gene polymorphisms in coeliac disease: differences between DQ2 positive and negative patients

Predisposition to coeliac disease (CD) might be partially due to an individual pattern of hyper-inflammatory biased immune response. One of these patterns of intense response may be linked to the haplotype carrying HLA-DQ2 alleles and TNF −308A allele. However, 10 % of CD patients do not express the DQ2 heterodimer and these do not usually carry the TNF −308A allele. A similar response might be achieved by genes codifying other cytokines.ObjectivesTo study biallelic polymorphisms in genes codifying for TNFα, IL10, IL6 and TGFβ1 in DQ2 negative CD patients and to compare the results with DQ2 positive patients and healthy controls, in order to establish whether any of these polymorphisms have a role in CD susceptibility.MethodsTNF −308 (G > A), IL-6 −174 (G > C) and TGFB1 codon 10 (+ 869, T > C) and codon 25 (+ 915, G > C) polymorphisms and IL-10 haplotype of polymorphisms in positions −1082 (G > A), −819 (C > T) and −592 (C > A) were typed by a SSP-PCR technique.ResultsThe distribution of allele frequencies for TNF −308 is different between DQ2 positive CD patients and controls and the same occurs for haplotype frequencies of the IL10 promoter (−1082, −819, −592): The frequencies of the TNF −308A allele (p = 0.027), TNF −308A carriers (p = 0.031) and of IL10GCC haplotype are increased (p = 0.013) in DQ2 positive CD patients. However, the IL6 −174 allele G is more frequent in DQ2 negative patients than in healthy controls (p = 0.018), DQ2 negative controls (p = 0,018), and DQ2 positive patients (p = 0.008).ConclusionsDQ2 negative CD patients show an increased frequency of genotypes associated to IL6 high production. These were mainly allele G homozygous for the IL6 gene (−174) polymorphism. The IL6 −174GG genotype (homozygous) may be an additional risk marker for CD in DQ2 negative patients, representing an alternative susceptibility factor for CD when TNF −308A is negative.     

ABCB1 genetic variation and P-glycoprotein expression/activity in a cohort of Brazilian acute myeloid leukemia patients

Purpose

Polymorphisms in the ABCB1 gene may influence P-glycoprotein (Pgp) expression and/or activity. Because the population in Brazil is markedly heterogeneous, we analyzed the relationship between ABCB1 polymorphisms and Pgp expression/activity in Brazilian acute myeloid leukemia (AML) patients.

Methods

Acute myeloid leukemia samples from 109 patients were studied. ABCB1 gene variants rs1128503 (C1236T) and rs1045643 (C3435T) were analyzed by PCR-RFLP assay. Pgp expression and Pgp activity were analyzed by flow cytometry.

Results

There was a similar distribution of Pgp expression and activity on polymorphisms C1236T, C1236C, and T1236T for exon 12, and C3435T, C3435C, and T3435T for exon 26. An exception was observed in the lowest ratio of mean fluorescence intensity (MFI) median for Pgp expression in the TT genotype for both studied exons, and its correspondence to a low MFI median for Pgp activity. Pgp expression did not show impact on the response to remission induction therapy, but the MFI median of Pgp expression in the remission failure group was higher than that of the complete remission (CR) group of patients (p?=?0.04). Overall survival (OS) was significantly influenced by CR (p?=?0.0001). Better 5-year OS and 5-year event-free survival rates (p?=?0.04 and p?=?0.007, respectively) were achieved in patients presenting the genetic variant CC in exon 12 followed by those presenting the variant CT in exon 26 (p?=?0.001).

Conclusions

Polymorphisms in the ABCB1 gene and the levels of Pgp expression could be useful to identify prognostic in AML patients.     

Polymorphisms of LTA, LGALS2, and PSMA6 genes and coronary atherosclerosis: a pathological study of 1503 consecutive autopsy cases

ObjectiveRecent genome-wide association studies have identified polymorphisms of lymphotoxin-α (LTA), galectin-2 (LGALS2), and proteasome subunit a type 6 (PSMA6) genes as genetic risk factors for myocardial infarction (MI). However, their effects on coronary atherosclerosis, an intermediate phenotype of MI, remain largely unknown.MethodsWe investigated the correlation between polymorphisms of the LTA, LGALS2, and PSMA6 genes and the severity of pathological coronary stenosis index (CSI) and MI in 1503 consecutive autopsy cases of Japanese elderly patients.ResultsThe polymorphisms LTA rs1041981 and LGALS2 rs7291467 were associated with CSI with odds ratios of 1.54 (95% CI, 1.17–2.01; AA + CA over CC) and 1.62 (95% CI, 1.11–2.37; TT over CC + CT), respectively. PSMA6 rs1048990 was not associated with CSI. None of the SNPs was associated with MI in our sample.ConclusionOur findings indicate that the LTA and LGALS2 polymorphisms affect the subclinical phenotype of the coronary artery, which predisposes to the incidence of MI.     

IL1B genetic variation and plasma C-reactive protein level among young adults: the CARDIA study

ObjectiveInterleukin-1B (IL1B) modulates C-reactive protein (CRP) expression. However, whether IL1B genetic variation is associated with CRP level is unknown. Further, obesity, a state of low-grade inflammation that influences cellular IL-1 functions may modify this association.Methods and resultsStudy participants (N = 3289), 48% blacks and 52% whites, had CRP level measurements at year 7 and year 15 examinations as part of the CARDIA study. Ten tag single nucleotide polymorphisms (SNPs) that characterize common IL1B gene variation were genotyped. In SNP analysis, no significant associations with either level or change in time CRP were observed after multiple testing adjustments. However, global ILIB gene variation was associated with year 7 to year 15 change in CRP (global nominal p = 0.004, multiple testing corrected p = 0.048) among obese blacks. Compared to the commonest haplotype, a common haplotype that includes the SNP rs1143642 was associated with greater increases in CRP from year 7 to year 15 among obese blacks and whites while another common haplotype that includes the SNP rs3917356 was associated with decreased change in CRP from year 7 to year 15 among obese blacks. The rare alleles of ILIB SNPs, SNP 7114 (rs1143642) and SNP 3298 (rs3917356), were associated with greater increases and decreases in CRP from year 7 to year 15 among blacks, respectively, compared to their common variants.ConclusionIL1B genetic variation may have a role in CRP level regulation and this association may be modified by obesity.     

Association of ALOX5AP haplotypes with susceptibility to coronary artery disease in a Chinese Han population

BackgroundThe 5-lipoxygenase activating protein (FLAP), encoded by the activating 5-lipoxygenase (ALOX5AP) gene, is a crucial mediator of the biosynthesis of leukotrienes, which have been implicated in atherosclerosis. This study investigates whether ALOX5AP polymorphisms are associated with coronary artery disease (CAD) in a Chinese Han population.MethodsThe promoter, exons, splice site region and 3′-untranslated region of the ALOX5AP gene were sequenced in 48 subjects. Three polymorphic sites (? 1340T/G, + 8733T/C, + 20616G/C) found through sequencing were evaluated in 656 patients with angiographically proven CAD and 678 controls with normal coronary angiograms using a polymerase chain reaction and restriction fragment length polymorphism assay. Allelic, genotypic linkage disequilibrium and haplotypic association testing were performed using SHEsis and LDA software. Binary logistic regression was used to control for the presence of vascular risk factors.ResultsSeven single nucleotide polymorphisms (SNPs) were found through screening. No significant differences in allele carriers and genotype frequencies of the ALOX5AP polymorphisms were observed between the two groups. However, when the results of the three SNPs were combined, there was a significant association between two of the haplotypes and the risk of CAD. The haplotype GCG had a significantly greater frequency in patients than in controls (P < 0.001, OR = 1.728, 95%CI = 1.375–2.171), and the frequency of haplotype TCG was higher in controls (P < 0.001, OR = 0.623, 95%CI = 0.519–0.748).ConclusionThe data indicate that ALOX5AP gene variation is a genetic factor associated with interindividual differences in CAD risk.     

FADS gene polymorphisms in Koreans: association with ω6 polyunsaturated fatty acids in serum phospholipids, lipid peroxides, and coronary artery disease

ObjectiveWe investigated the association of polymorphisms in FADS genes with polyunsaturated fatty acids (PUFAs) in serum phospholipids, lipid peroxides, and coronary artery disease (CAD) in Koreans.MethodsIn this case–control study, CAD patients (n = 756, 40–79 years) and healthy controls (n = 890) were genotyped for rs174537 near FADS1 (FEN1 rs174537G > T), FADS2 (rs174575, rs2727270), and FADS3 (rs1000778). We calculated the odds ratios (ORs) for CAD risk and measured serum PUFA composition and lipid peroxide.ResultsAmong four SNPs, only rs174537G > T differed in allele frequencies between controls and CAD patients after adjustment for age, BMI, cigarette smoking, alcohol consumption, hypertension, diabetes mellitus, and hyperlipidemia (P = 0.017). The minor T allele was associated with a lower risk of CAD [OR 0.75 (95%CI 0.61–0.92), P = 0.006] after adjustment. rs174537T carriers had a significantly higher proportion of linoleic acid (LA, 18:2ω6), lower arachidonic acid (AA, 20:4ω6), and lower ratios of AA/dihomo-γ-linolenic acid (DGLA, 20:3ω6) and AA/LA than G/G subjects in both control and CAD groups. In the control group, 174537T carriers had significantly lower levels of total- and LDL-cholesterol, malondialdehyde, and ox-LDL. In CAD patients, rs174537T carriers showed a larger LDL particle size than G/G subjects. The proportion of AA in serum phospholipids positively correlated with LDL-cholesterol, ox-LDL, and malondialdehyde in controls and with 8-epi-prostaglandin F_2α in both control and CAD groups.ConclusionThe rs174537T is associated with a lower proportion of AA in serum phospholipids and reduced CAD risk, in association with reduced total- and LDL-cholesterol and lipid peroxides.     

ABCB1 gene polymorphisms and haplotype analysis in colorectal cancer

Purpose  The aim of this study was to determine the significance of three most common single-nucleotide polymorphisms (SNPs) of ABCB1 gene in the development of colorectal cancer and to estimate the influence of these SNPs to surviving patients' treatment combination adjuvant therapy 5-fluorouracil/leucovorin. Haplotype structure of ABCB1 was analysed, and degree of linkage disequilibrium (LD) between SNPs of ABCB1 was estimated. Materials and methods  Tumour specimens of 95 patients with colorectal cancer and blood samples of 95 healthy cases were studied. Genotyping of ABCB1 gene was performed by automated sequencing or polymerase chain reaction-restriction fragment length polymorphism method. Comparison of frequencies of alleles/genotypes/haplotypes between the studied group (colorectal cancer samples) and the control group (blood samples) were analysed. These results were correlated with the surviving patients after treatment of adjuvant chemotherapy. Results  Significant differences in ABCB1 _1236C>T (p = 0.00043) and ABCB1 _2677G>T/A (p = 0.04) genotype distribution and T₁₂₃₆ allele distribution (CT₁₂₃₆ or TT₁₂₃₆ vs CC₁₂₃₆; p = 0.0499, OR = 0.55, Fi–Yule coefficient = 0.14) were found. A strong LD between ABCB1 _1236C>T and ABCB1 _2677G>T/A SNPs (D′ = 0.621, r ² = 0.318) was detected. All SNPs were located in one haplotype block. There were significant differences in haplotype distributions between colorectal cancer patients and healthy population (p = 0.03). Significant differences in survival probability of colorectal cancer patients' treatment chemotherapy according to allele of ABCB1 _3435C>T was observed. Survival probability of patients with wild-type C₃₄₃₅ allele were higher than among patients without this allele (p = 0.04572). Conclusions  These results suggested that three studied SNPs of ABCB1 were located in one haplotype block. Differences in ABCB1 _1236C>T and ABCB1 _2677G>T/A genotypes and T₁₂₃₆ allele distribution between investigated populations indicate significant impact of these SNPs on risk of development of colorectal cancer. Polymorphism ABCB1 _3435C>T may be a prediction marker of cancer chemotherapy effectiveness. Differences in haplotype distributions between colorectal cancer patients and healthy population suggested that other potential SNPs, especially in regulatory region of ABCB1 gene, may influence P-glycoprotein expression and function.     

Gene-nutrient interactions and gender may modulate the association between ApoA1 and ApoB gene polymorphisms and metabolic syndrome risk

ObjectiveDyslipidemia is a key feature of the metabolic syndrome (MetS), which is determined by both genetic and dietary factors.MethodsWe determined the relationships between ApoA1 and ApoB polymorphisms and MetS risk, and whether dietary fat modulates this in the LIPGENE-SU.VI.MAX study of MetS cases and matched controls (n = 1754).ResultsApoB rs512535 and ApoA1 rs670 major G allele homozygotes had increased MetS risk (OR 1.65 [CI 1.24, 2.20], P = 0.0006; OR 1.42 [CI 1.08, 1.87], P = 0.013), which may be, partly, explained by their increased abdominal obesity and impaired insulin sensitivity (P < 0.05) but not dyslipidemia. Interestingly these associations derived primarily from the male GG homozygotes (ApoB rs512535 OR 1.92 [CI 1.31, 2.81], P = 0.0008; ApoA1 rs670 OR 1.50 [CI 1.05, 2.12], P = 0.024). MetS risk was exacerbated among the habitual high-fat consumers (>35% energy) (ApoB rs512535 OR 2.00 [CI 1.14, 3.51], P = 0.015; OR 1.58 [CI 1.11, 2.25], P = 0.012 for ApoA1 rs670). In addition a high monounsaturated fat (MUFA) intake (>14% energy) increased MetS risk (OR 1.89 [CI 1.08, 3.30], P = 0.026 and OR 1.57 [CI 1.10, 2.40], P = 0.014 for ApoB rs512535 and ApoA1 rs670, respectively). MetS risk was abolished among the habitual low-fat consumers (<35% energy). Saturated and polyunsaturated fat intake did not modulate MetS risk.ConclusionApoB rs512535 and ApoA1 rs670 may influence MetS risk. Apparent modulation of these associations by gender and dietary fat composition suggests novel gene-gender-diet interactions.     

Akt2 Gene common allelic variants in insulin resistance and the metabolic syndrome

Background and aimSeveral lines of evidence indicate that glucose homeostasis may be under the control of Akt2 and it can therefore be seen as a candidate gene for human insulin resistance (IR) and related phenotypes. The aim of our study was the identification of Akt2 common allelic variants that might modulate susceptibility to IR and related metabolic abnormalities.Methods and resultsThe Akt2 gene (exons, 5′ and 3′ regulatory regions) was re-sequenced in samples of 50 blood donors from the Gargano region. Two single nucleotide polymorphisms (SNPs) in 5′ (rs11669332 and rs969531) and two in 3′ (rs2304186 and C1658T) regulatory regions were exploited in an association study using 661 healthy unrelated Caucasian individuals from the same region.Individuals being homozygous for the T allele of rs11669332 (an Akt2 promoter) showed lower systolic blood pressure (p = 0.04), total/HDL cholesterol ratio (p = 0.02) and the metabolic syndrome score (p = 0.04), while carriers of the A allele of rs969531 (in 5′-UTR) showed higher systolic blood pressure (p = 0.027). The association between phenotypic traits and possible haplotypes was tested as well. However, no haplotype affecting the risk of metabolic abnormalities was found.ConclusionsTwo variants in 5′ regulatory region of Akt2 gene are associated and may modulate susceptibility to IR and related metabolic abnormalities.     

Variants within the nitric oxide synthase 1 gene are associated with stroke susceptibility

ObjectiveAnimal studies have allowed important insights into the role of the nitric oxide synthase (NOS) enzymes in atherosclerosis and hypertension, as well as in stroke. In this study we tested the hypothesis that the NOS1 and NOS3 genes, respectively encoding neuronal NOS (nNOS) and endothelial NOS (eNOS), influence stroke susceptibility and outcome after a stroke event.MethodsWe conducted a case–control association study in 551 ischemic stroke patients and 530 controls to assess the role of NOS1 and NOS3 variants in stroke susceptibility. The same genes were tested for association with stroke outcome in a subset of 431 patients.ResultsFour NOS1 single nucleotide polymorphisms (SNPs) (rs2293050, rs2139733, rs7308402 and rs1483757) and four haplotypes were significantly associated with stroke susceptibility after adjusting for demographic, clinical and life-style risk factors, and correcting for multiple testing using the false discovery rate (FDR) method (SNPs: 0.004 < _uncorrected P < 0.007 and 0.036 < FDR q < 0.048; haplotypes: 0.001 < _uncorrected P < 0.010 and 0.018 < FDR q < 0.032). NOS1 variants were not associated with stroke outcome. We did not find any evidence for a role of the NOS3 gene in stroke susceptibility or outcome.ConclusionOur results highlight NOS1 as a susceptibility factor for stroke, but do not corroborate previous NOS3 association findings with stroke risk. nNOS is known to play a major role in atherosclerosis development and in blood flow regulation, and it is plausible that its influence in stroke may be mediated through these two main clinical risk factors.     

Thioredoxin interacting protein genetic variation is associated with diabetes and hypertension in the Brazilian general population

ObjectiveTo investigate the relationship between TXNIP polymorphisms, diabetes and hypertension phenotypes in the Brazilian general population.MethodsFive hundred seventy-six individuals randomly selected from the general urban population according to the MONICA-WHO project guidelines were phenotyped for cardiovascular risk factors. A second, independent, sample composed of 487 family-trios from a different site was also selected. Nine TXNIP polymorphisms were studied. The potential association between TXNIP variability and glucose-phenotypes in children was also explored. TXNIP expression was quantified by real-time PCR in 53 samples from human smooth muscle cells primary culture.ResultsTXNIP rs7211 and rs7212 polymorphisms were significantly associated with glucose and blood pressure related phenotypes. In multivariate logistic regression models the studied markers remained associated with diabetes even after adjustment for covariates. TXNIP rs7211 T/rs7212 G haplotype (present in approximately 17% of individuals) was significantly associated to diabetes in both samples. In children, the TXNIP rs7211 T/rs7212 G haplotype was associated with fasting insulin concentrations. Finally, cells harboring TXNIP rs7212 G allele presented higher TXNIP expression levels compared with carriers of TXNIP rs7212 CC genotype (p = 0.02).ConclusionCarriers of TXNIP genetic variants presented higher TXNIP expression, early signs of glucose homeostasis derangement and increased susceptibility to chronic metabolic conditions such as diabetes and hypertension. Our data suggest that genetic variation in the TXNIP gene may act as a “common ground” modulator of both traits: diabetes and hypertension.     

The differences in the involvements of loci of promoter region and Ile50Val in interleukin-4 receptor α chain gene between atopic dermatitis and Japanese cedar pollinosis

BackgroundAtopic dermatitis (AD) and Japanese cedar pollinosis (JCP) are common chronically allergic diseases associated with the activation of T-helper 2 cells. Recent studies have shown that polymorphisms in the genes for IL-4 receptor α chain (IL4RA) may contribute to susceptibility of AD and JCP, although the differences in the involvements of loci of IL4RA gene between AD and JCP are unclear. In this study, we investigated the role of polymorphisms in IL-4RA gene in conferring susceptibility to the development of AD and/or JCP using a family analysis and an association analysis in a Japanese population.MethodsFive polymorphisms in the IL-4RA gene, C-3223 T, T-1914C, T-890C, Ile50Val and Glu375Ala, have been genotyped using PCR-based methods in 75 trios families, including 15 AD families, 30 JCP families, and 30 families with combination of AD and JCP in the family analysis. Forty-five AD, 60 JCP and 125 control children constituted the association study.ResultsThe transmission disequilibrium test showed that the allele of Ile50 was significantly transmitted to children with JCP alone (p < 0.05). Haplotype analysis showed that the -3223 T/Ile50 haplotype was preferentially transmitted to both AD (p < 0.01) and JCP children (p < 0.01), while that the C-3223/Ile50 haplotype was preferentially transmitted to only JCP children (p < 0.01). The association study showed that -3223 T and haplotype of -3223 T/Ile50 were associated with aD children, but not with JCP. Ile50 was associated with both AD and JCP.ConclusionsOur data suggest that -3223 T and the -3223 T/Ile50 haplotype were risk factors for AD. Ile50 allele seems to be involved in both JCP and AD. Interactions of the IL-4RA loci may play a role both conferring susceptibility and modulating severity of AD.     

Proinflammatory HLA-DRB1*01-haplotype predisposes to ST-elevation myocardial infarction

BackgroundMajor histocompatibility complex (MHC) gene region harbours haplotypes that associate with coronary artery disease (CAD). Their role in ST-elevation infarction (STEMI) or on the inflammatory level is not known.MethodsFour candidate MHC markers were analyzed by real-time quantitative PCR and constructed into haplotypes from patients with STEMI (n = 162), matched controls with no CAD (n = 319) and general population sample (n = 149). High sensitivity C-reactive protein (hsCRP) was assessed in a follow-up visit from patients (n = 86) and at inclusion from other study subjects.ResultsThe haplotype with one copy of HLA-DRB1*01, C4A, C4B but no HLA-B*35 doubled the risk of STEMI (OR = 2.15, 95%CI = 1.11–4.15, p = 0.020 for patients vs. controls, and OR = 2.26, 95%CI = 0.97–5.24, p = 0.052 for patients vs. population sample). The association between patients and controls persisted in multivariate analyses. The frequency of the haplotype was 5.86% (n = 19/324) in patients, 2.82% (n = 18/638) in controls and 2.68% (n = 8/298) in population sample. None of the individual MHC markers alone showed significant association with STEMI.In multivariate analyses, the haplotype carriers had higher hsCRP levels in patients (median 3.37 mg/L in carriers vs. 1.14 mg/L in non-carriers, p = 0.019) and in controls (median 2.90 mg/L vs. 1.21 mg/L, p = 0.009, respectively).ConclusionThe MHC haplotype associates with STEMI and elevated baseline hsCRP levels. The results are in concordance with previous data on non-STEMI patients, implying that a HLA-DRB1*01 – related haplotype increases the risk of CAD, possibly though increased inflammation.     

Polymorphisms of POR, SULT2A1 and HSD11B1 in children with premature adrenarche

Premature adrenarche (PA) refers to an earlier than normal increase in adrenocortical androgen production. The pathogenesis of PA remains largely unknown. We hypothesized that common polymorphisms at P450 oxidoreductase (POR), steroid sulfotransferase (SULT2A1), or 11β-hydroxysteroid dehydrogenase type 1 (HSD11B1) genes could contribute to the polygenic pathogenesis of PA. We performed a case–control study on the polymorphisms rs1057868 at POR, rs182420 at SULT2A1, and rs12086634 at HSD11B1. The study cohort comprised 73 prepubertal children with PA (defined by clinical signs) and 97 age- and gender-matched healthy controls from a Finnish Caucasian population. Genotype distributions and clinical and metabolic phenotypes were determined. The genotype distributions of the polymorphisms were similar between the study groups. No variant was associated with alterations in serum adrenal steroid concentrations. The minor C variant at SULT2A1 was associated with higher serum sex hormone binding globulin (SHBG) concentrations (T/T, n = 64 vs T/C&;C/C, n = 33; mean 94 vs 116 nmol/L; P = .001) and a trend for lower dehydroepiandrosterone sulfate/dehydroepiandrosterone ratios in the controls (P = .06), and with higher plasma total cholesterol concentrations in the PA subjects (T/T, n = 42 vs T/C&;C/C, n = 31; 4.0 vs 4.6 mmol/L; P < .001). The minor G variant at HSD11B1 was associated with lower plasma triglyceride concentration in the controls (T/T, n = 65 vs T/G&;G/G, n = 32; 0.61 vs 0.49 mmol/L; P = .013). Common polymorphisms at POR, SULT2A1 or HSD11B1 were not associated with PA in a Finnish Caucasian population.