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PubMed2006

ABCB1 polymorphisms influence the response to antiepileptic drugs in Japanese epilepsy patients.

OBJECTIVES: The efflux transporter P-glycoprotein encoded by the ATP-binding cassette (ABC)B1 gene may play a role in drug-resistant epilepsy by limiting gastrointestinal absorption and brain access of antiepileptic drugs (AEDs). Our objective was to investigate the effect of ABCB1 polymorphisms on AED responsiveness and on the pharmacokinetics of carbamazepine (CBZ) in epileptic patients with the indication for CBZ therapy. METHODS: The ABCB1 T-129C, C1236T, G2677T/A and C3435T polymorphisms were genotyped in 210 Japanese epileptics who had been prescribed AEDs, including CBZ, for longer than 2 years. Haplotype and diplotype frequencies were estimated by expectation-maximization algorithm. Drug resistance was determined by the presence of seizures. Association of the polymorphisms with the risk of drug resistance was estimated by logistic regression analysis and the odds ratios (ORs) were adjusted for the clinical factors affecting the outcome of AED therapy. CBZ concentrations to the dose (C/D) ratios were compared among the ABCB1 polymorphisms. RESULTS: Drug-resistant patients were more likely to have the T allele (OR [95% confidence interval (CI)], 2.02 [1.14-3.58]) and the TT genotype at C3435T (OR [95% CI], 3.64 [1.16-11.39]), and the TT genotype at G2677T/A (OR vs the GG genotype [95% CI], 3.43 [1.01-11.72]). The frequency of the T-T-T haplotype at C1236T, G2677T/A and C3435T was significantly higher (OR [95% CI], 1.84 [1.03-3.30]), and the CC-GG-CC diplotype was lower (OR [95% CI], 0.09 [0.01-0.85]) in the drug-resistant patients than in the drug-responsive patients. None of the ABCB1 polymorphisms were observed to influence the C/D ratios of CBZ. CONCLUSION: We demonstrated that ABCB1 polymorphisms may influence the AED responsiveness without significant changes in the plasma concentrations of CBZ. Our findings were the inverse of previous results in European epileptics, thus the influence of ABCB1 polymorphisms on the AED responsiveness and/or the P-glycoprotein activity may vary among races.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2006

Arylamine N-acetyltransferase gene polymorphisms: markers for atopic asthma, serum IgE and blood eosinophil counts.

INTRODUCTION: Polymorphisms in N-acetyltransferase 2 (NAT2), present on chromosome 8p22, are responsible for the N-acetylation variants, which segregate human populations into rapid, intermediate and slow acetylators and influence the susceptibility towards atopic disorders. We have undertaken a study of the North Indian population to screen for various NAT2 polymorphisms and to investigate their association with atopic asthma and related phenotypes. METHODS: First, to establish linkage of the 8p22 region with asthma, 158 families were recruited from North India. Next, a total of 219 unrelated atopic asthmatics and 210 unrelated healthy controls were recruited for case-control disease association studies. RESULTS: A suggestive linkage was observed with microsatellite marker D8S549, 2.6 MB upstream of NAT2. By sequencing the DNA of 40 individuals, the T111C, G191A, A434C and C759T single nucleotide polymorphisms (SNPs) in NAT2 were found to be nonpolymorphic in our population and a pattern of strong linkage disequilibrium was observed among the T341C, C481T and A803G polymorphisms. Thus, a total of 429 individuals were genotyped for the C481T and unlinked C282T polymorphisms. The C481T polymorphism was found to be significantly associated with asthma in our case-control studies at the genotype level (Armitage p = 0.00027). C481T also showed a marginal association with serum total IgE (TsIgE) (p = 0.022). Furthermore, percent blood eosinophil counts were found to be significantly higher in patients carrying the 481T allele (p = 0.0037). Significant association was also detected with respect to the C282T polymorphism and TsIgE (p = 0.008). Moreover, C_T was found to be an important risk (p = 0.001), while C_C was a major protective haplotype (p = 0.0005). The associations remained significant after Bonferroni correction for multiple testing. CONCLUSION: In summary, the genetic variants of the NAT2 gene do not seem to affect asthma alone, but act as modulators of asthma-related traits, such as serum IgE and blood eosinophil counts, and therefore could serve as genetic markers.

Adolescent↗

PubMed2005

Peroxisome proliferator-activated receptor alpha L162V polymorphism in nonalcoholic steatohepatitis and genotype 1 hepatitis C virus-related liver steatosis.

BACKGROUND: Peroxisome proliferator-activated receptor alpha (PPARalpha) plays important roles in lipid metabolism. A recently discovered L162V polymorphism of the PPARalpha gene is associated with enhanced transcriptional activity. In this study, the frequency of L162V was investigated in nonalcoholic steatohepatitis (NASH) and genotype 1 hepatitis C virus (HCV)-related liver steatosis. METHODS: Seventy-two NASH and 141 HCV-infected patients (54 with steatosis, 87 without steatosis) and 119 healthy controls were included. L162V polymorphism of the PPARalpha gene was analyzed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). RESULTS: PCR and RFLP analysis of the related gene segment was successful in 93%, 96%, and 100% of NASH and HCV-infected patients and controls, respectively. The frequency of the L162V polymorphism was similar in the NASH and HCV-infected patients and controls (5.9%, 3.6%, and 2.5%, respectively). No difference in the frequency of this polymorphism was observed in HCV-infected patients with or without significant liver steatosis. L162V was not associated with obesity, type 2 diabetes mellitus, hypercholesterolemia, or hypertriglyceridemia. CONCLUSIONS: Neither NASH nor genotype 1 HCV-related liver steatosis seems to be associated with the PPARalpha L162V polymorphism. This polymorphism may have no association with the presence of type 2 diabetes mellitus, obesity, or various blood lipid alterations in NASH and HCV-infected patients.

Adult↗

PubMed2006

Phase I and Phase II enzyme polymorphisms and childhood cancer.

Childhood cancers continue to be challenging clinical entities whose etiology, demographic characteristics, clinical progression, treatment efficacy, and outcomes remain incompletely understood. Research suggests that multiple environmental and genetic factors may play crucial roles in the pathophysiology of many of these malignancies. Recent attention has been directed to the role of carcinogen metabolizing enzymes in the etiology and progression of cancer in both adults and children due to their multitude of polymorphic variants and their intimate interaction with environmental factors. In particular, xenobiotic metabolizing enzymes (XME), which are intimately involved in the activation and deactivation of many environmental carcinogens, have become an area of significant interest. Traditionally, these enzymes have been classified into either phase I or phase II enzymes depending on their substrates, activity, and occasionally based on their sequence in the metabolic pathways, and have been demonstrated to have numerous polymorphic variants. Phase I enzymes predominantly consist of cytochrome enzymes responsible for mixed function oxidase activity, whereas phase II enzymes are frequently conjugation reactions necessary for drug metabolism or the further metabolism of phase I enzyme products. Current research has discovered numerous interactions between polymorphisms in these enzymes and changes in cancer susceptibility, treatment efficacy, and clinical outcomes in childhood cancer. Furthermore, studies of polymorphisms in these enzymes have demonstrated to have synergistic/antagonistic interactions with other XME polymorphisms and demonstrate variable influences on disease pathophysiology depending on the patient's ethnic background and environmental milieu. Continuing research on the role of polymorphisms in phase I and phase II enzymes will likely further elucidate the intimate role of these polymorphisms with environmental factors in the etiology of childhood cancer.

Adolescent↗

PubMed1997

No independent associations of LMP2 and LMP7 polymorphisms with susceptibility to develop IDDM.

Results from a recent study suggested that polymorphisms within the HLA class II genes LMP2 and LMP7 were associated with the susceptibility for developing IDDM, and that this association could not be explained by linkage disequilibrium to HLA-DR or -DQ genes. We typed 285 IDDM patients and 337 HLA-DRB1-DQA1-DQB1 genotypically matched control subjects from an ethnically homogeneous population for both the G/T polymorphism in intron 6 of the LMP7 gene and the Arg-His polymorphism in the LMP2 gene. In addition, we typed IDDM families in which at least one parent was homozygous for a DRB1-DQA1-DQB1 haplotype and performed a transmission/disequilibrium test of these LMP polymorphisms. Our data suggest that none of these LMP2 or LMP7 polymorphisms are independently associated with IDDM susceptibility, in contrast to what has been previously reported by others. Further, our results suggest that one partial explanation for the previously reported independent association between IDDM and these LMP polymorphisms may have been that patients and control subjects were not matched for DRB1*04 subtypes. Our results emphasize the need for a complete matching for DRB1, DQA1, and DQB1 alleles between patients and control subjects when attempting to detect independent effects of other polymorphisms in the HLA complex on IDDM susceptibility or protection.

Cysteine Endopeptidases↗

PubMed1997

Polymorphism of the beta3-adrenergic receptor gene affects basal metabolic rate in obese Finns.

Low basal metabolic rate (BMR) is a risk factor for weight gain and obesity. The polymorphism at codon 64 of the beta3-adrenergic receptor gene has been suggested to be associated with BMR. We investigated the frequency of the Trp64Arg of the beta3-adrenergic receptor gene and the effects of this polymorphism on BMR in obese Finns. Altogether, 170 obese subjects (29 men, 141 women, BMI 34.7 +/- 3.8 kg/m2, mean +/- SD) participated in the study. The frequency of the Trp64Arg polymorphism was 19%. None of the obese subjects were homozygous for the Arg-encoding allele. The frequency of the Trp64Arg polymorphism in obese Finns did not differ from nonobese and normoglycemic control subjects. BMR adjusted for lean body mass and age was lower in subjects with the Trp64Arg polymorphism (n = 20) than in normal homozygotes Trp64Trp (n = 99) (1,569 +/- 73 vs. 1,635 +/- 142 kcal/day, P = 0.004). For the female group (n = 98), the respective values were 1,501 +/- 66 kcal/day vs. 1,568 +/- 127 kcal/day (P = 0.004). There were no significant differences in weight, BMI, waist-to-hip ratio, lean body mass, percentage of fat, and respiratory quotient between the groups with or without the Trp64Arg polymorphism. Neither serum glucose nor insulin levels differed between the two groups. We conclude that the Trp64Arg polymorphism of the beta3-adrenergic receptor gene affects basal metabolic rate in obese Finns but does not have significant effect on glucose metabolism.

Adult↗

PubMed2000

Promoter polymorphism T(-107)C of the paraoxonase PON1 gene is a risk factor for coronary heart disease in type 2 diabetic patients.

The serum enzyme paraoxonase (PON) protects LDLs from oxidative stress. We recently identified promoter polymorphisms of the PON gene that strongly affect gene expression and serum levels of the enzyme. The present study tested the hypothesis that promoter polymorphism T(-107)C could be a risk factor for vascular disease in type 2 diabetic patients by virtue of its ability to modulate serum concentrations of the antioxidant enzyme. The low-expressor genotype (TT) was associated with significantly lower serum PON concentrations, and it was over-represented in type 2 diabetic patients with coronary heart disease (CHD) (TT vs. TC+CC: odds ratio [OR] 1.64 [95% CI 1.03-2.61], P < 0.05). The association of the low-expressor genotype with an increased risk of disease was independent of other risk factors, including the coding region Q191R polymorphism (OR 2.12 [95% CI 1.19-3.70], P = 0.01). However, an interaction of the promoter polymorphism with the Q191R polymorphism, which was previously identified as an independent risk factor, was observed. The low-expressor promoter allele (-107T) associated with the high-risk 191R allele showed a lower-than-expected level of risk (OR 2.21 vs. the expected 4.76). The data are consistent with the hypothesis that low expression of the antioxidant enzyme PON increases the risk of CHD. Moreover, the promoter polymorphism appears to have a modulating effect on risk that is associated with the coding region polymorphism Q191R. This study indicates a strong genetic component to the antioxidant capacity of HDLs.

Aryldialkylphosphatase↗

PubMed2005

Prognostic effect of insertion/deletion polymorphism of the ace gene on renal and cardiovascular clinical outcomes in Chinese patients with type 2 diabetes.

OBJECTIVE: The insertion/deletion (I/D) polymorphism of the ACE gene has been reported to be associated with diabetic microvascular or macrovascular complications. The aim of the present study was to investigate the prognostic effect of I/D polymorphism on renal and cardiovascular clinical outcomes in Chinese patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: A consecutive cohort of 1,281 Chinese patients with type 2 diabetes were followed for 41.3 +/- 21.6 months. Renal end points were defined as renal death and events (need for dialysis, plasma creatinine >/=500 micromol/l, or doubling of plasma creatinine of baseline value >/=150 micromol/l). Cardiovascular end points were defined as cardiovascular death and events, which included ischemic heart disease, heart failure, cerebrovascular accident, and revascularization requiring hospital admission. The I/D polymorphism of the ACE gene was examined by PCR followed by agarose gel electrophoresis. RESULTS: The frequencies of ACE gene I/D polymorphisms were in Hardy-Weinberg equilibrium. Patients who developed a renal end point (n = 98) had higher frequencies of DD genotype (19.4 vs. 10.8%, P = 0.018) and D allele (41.3 vs. 31.8%, P = 0.006) compared with subjects who did not (n = 1,183). The cumulative rates of renal end points were 10.0, 19.2, and 24.4% in the II (n = 595), DI (n = 539), and DD genotype carriers (n = 147), respectively (log rank P = 0.004). In multiple Cox regression analysis, the occurrence of renal end points remained significantly influenced by I/D polymorphism with a dominant deleterious effect of the DD genotype (DD versus II, adjusted hazard ratio 2.80 [95% CI 1.49-5.29]). There was no prognostic effect of I/D polymorphism on cardiovascular end points. CONCLUSIONS: The DD genotype of the ACE I/D polymorphism was an independent risk factor for renal but not cardiovascular end points in Chinese patients with type 2 diabetes.

Aged↗

PubMed2006

Functional polymorphisms of UCP2 and UCP3 are associated with a reduced prevalence of diabetic neuropathy in patients with type 1 diabetes.

OBJECTIVE: We studied the association between polymorphisms in the UCP genes and diabetes complications in patients with type 1 diabetes. RESEARCH DESIGN AND METHODS: We analyzed 227 patients with type 1 diabetes using PCR and subsequent cleavage by restriction endonucleases for the promoter variants A-3826G in the UCP1 gene, G-866A in the UCP2 gene, and C-55T in the UCP3 gene. RESULTS: No effect of the A-3826G polymorphism in the UCP1 gene on diabetes complications was found. Patients who were heterozygous or homozygous for the G-866A polymorphism in the UCP2 gene or the C-55T polymorphism in the UCP3 gene had a significantly reduced prevalence of diabetic neuropathy (UCP2: odds ratio 0.44 [95% CI 0.24-0.79], P = 0.007; UCP3: 0.48 [0.25-0.92], P = 0.031), whereas there was no association with other diabetes complications. This effect was stronger when G-866A and C-55T occurred in a cosegregatory manner (UCP2 and UCP3: 0.28 [0.12-0.65], P = 0.002). Furthermore, a multiple logistic regression model showed an age- and diabetes duration-independent effect of the cosegregated polymorphisms on the prevalence of diabetic neuropathy (P = 0.013). CONCLUSIONS: Our data indicate that both the G-866A polymorphism in the UCP2 gene and the C-55T polymorphism in the UCP3 gene are associated with a reduced risk of diabetic neuropathy in type 1 diabetes. Thus, the results presented here support the hypothesis that higher expression of uncoupling protein might prevent mitochondria-mediated neuronal injury and, ultimately, diabetic neuropathy.

Adult↗

PubMed1995

Relationship of restriction fragment length polymorphisms (RFLP) at the bovine calpastatin locus to calpastatin activity and meat tenderness.

Restriction fragment length polymorphisms (RFLP) have been identified at the bovine calpastatin locus. The objective of the present study was to determine whether these polymorphisms are related to variations in calpastatin activity or beef tenderness in unrelated animals of mixed breeding. A sample of 83 crossbred steers from sires representing eight different breeds was examined to determine this relationship. A 2.2-kb cDNA coding for domains 2 through 4 plus a 3' untranslated region of bovine skeletal muscle calpastatin was used as a probe for calpastatin RFLP. Polymorphisms were found using the restriction enzymes BamHI and EcoRI. Polymorphic restriction fragments for BamHI were 9.0 and 5.0 kb and for EcoRI were 6.0 and 4.0 kb. Allelic frequencies for BamHI restriction fragments were .53 for the 9.0-kb allele and .47 for the 5.0-kb allele. Allelic frequencies for EcoRI restriction fragments were .43 for the 6.0-kb allele and >57 for the 4.0-kb allele. No polymorphisms were identified using the restriction enzymes BglII, DraI, or PstI. No associations between EcoRI and BamHI RFLP and 24-h calpastatin activity of Warner-Bratzler shear force at 14 d postmortem were detected. Therefore, the polymorphic EcoRI and BamHI restriction sites within the bovine calpastatin locus do not detect DNA sequence differences responsible for variation in calpastatin activity or tenderness of aged beef. Therefore, these polymorphisms cannot be used to predict tenderness of aged beef from unrelated animals of mixed breeding. These results do not exclude the possibility that other DNA sequences in or near the bovine calpastatin gene are responsible for variation in calpastatin activity or meat tenderness. The lack of a relationship between these calpastatin RFLP and meat tenderness must be distinguished from the well-documented relationship between calpastatin activity and meat tenderness. Therefore, further development of calpastatin-based methods for predicting beef tenderness in unrelated animals of mixed breeding should focus on basic factors influencing calpastatin activity at the molecular and cellular level.

Alleles↗

PubMedDate not supplied

A polymorphism in the BCL-6 gene is associated with follicle center lymphoma.

Follicle center lymphoma (FCL) accounts for approximately 40% of all non-Hodgkin's lymphomas (NHL). The genetic-environmental interactions involved in the etiology and pathogenesis of this disease are unknown. In our previous study a single nucleotide polymorphism (SNP) (397C) in the regulatory untranslated first intron region of the BCL-6 gene was found in four of the eight FCL patients but in none of the 10 healthy controls. To further evaluate the potential association between the 397C allele of the BCL-6 gene and FCL, we performed a case-control study. Genomic DNA was isolated from 85 FCL patients, from 98 control cases without a previous history of malignancy, treated at Stanford University Medical Center for non-malignant disorders and from 90 samples from the DNA Polymorphism Discovery Resource. The 397G and the 397C polymorphic alleles were identified by a PCR-RFLP method. To evaluate the possible effect of this polymorphism on gene expression, BCL-6 mRNA levels in nine FCL tumors with the 397G-G genotype and in nine FCL tumors with the 397G-C genotype were measured by quantitative real-time RT-PCR. The 397C polymorphic allele was found in 32 FCL cases (37.6%), in 20 controls (20.4%) and in 17 (18.9%) samples from the DNA Polymorphism Discovery Resource. The prevalence of the 397G-C and 397C-C genotypes was significantly higher in FCL cases than in control group (p = 0.01). No difference in BCL-6 gene expression was observed between FCL cases with 397G-G and 397G-C genotypes. The present study demonstrates a possible association between the 397C allele of the BCL-6 proto-oncogene and FCL. The similar levels of BCL-6 mRNA expression in 397G-G and in 397G-C FCL cases suggests that any possible oncogenic effect of the polymorphic allele would not simply be related to a direct effect on BCL-6 gene expression and suggests the existence of other FCL susceptibility genes that are in linkage disequilibrium with the 397C allele of the BCL-6 gene.

DNA-Binding Proteins↗

PubMed2005

Polymorphism of matrix metalloproteinase-3 promoter gene as a risk factor for coronary artery lesions in Kawasaki disease.

Kawasaki disease (KD) is a major cause of acquired coronary artery diseases in childhood. The serum levels of matrix metalloproteinase (MMP)-3 and MMP-9 in KD have been reported to be significantly higher than other diseases. Several studies have demonstrated that MMP-3 5A/6A polymorphism and MMP-9 C-1562T polymorphism modify each transcriptional activity in allele specific manner. We hypothesized that these polymorphisms may play a role as a risk factor for development of coronary artery lesions (CAL) in KD. Eighty-three patients, diagnosed with KD in Cheju National University Hospital from January 2000 to February 2004, were divided into two groups according to the presence of CAL. Genotyping of MMP-3 and MMP-9 gene polymorphisms were determined by restriction fragment length polymorphism. With regard to MMP-3 gene polymorphism, the KD with CAL group had a higher frequency of 6A/6A genotype than control group (p=0.0127) and the KD without CAL group (p=0.0036). However, no significant differences in the allele and genotype distributions of the MMP-9 polymorphism were observed. These findings suggest that MMP-3 6A/6A genotype may be an independent risk factor for CAL formation in KD.

Adolescent↗

PubMed2005

Cytokine production by whole blood cells: relationship to interleukin gene polymorphism and bone mass.

The aims of this study were to investigate the relationships between the production of interleukin-1 (IL-1), and IL-6 system by whole blood cells, and bone mineral density (BMD), and polymorphisms in IL-1 system and IL-6 gene in postmenopausal Korean women. The production of IL-1alpha, IL-1beta, IL-1 receptor antagonist (IL-1ra), IL-6, and soluble IL-6 receptor (sIL-6r) by lipopolysaccharide-stimulated whole blood cells was measured by ELISA in 110 subjects. Serum osteocalcin, C-telopeptide of type I collagen, and BMD at lumbar spine and proximal femur were measured. IL-1alphaC(-889)T polymorphism, IL-1beta C(-511)T polymorphism, 86-base pair variable number tandem repeat polymorphism in the IL-1ra gene, and IL-6 C(-634)G polymorphism were analyzed. The production of IL-1beta correlated positively with BMD at femoral neck, whereas the production of other ILs did not correlate with BMD at the skeletal sites examined. No significant differences in the production of ILs were observed among normal, osteopenic and osteoporotic postmenopausal women, and among the different IL system polymorphisms groups studied. No correlation between bone turnover markers and the production of ILs was noted. In conclusion IL-1beta may regulate bone metabolism at femoral neck, and the IL system polymorphism do not affect the production of ILs by whole blood cells.

Aged↗

PubMed1994

Nucleolar size polymorphisms in commercial layer chickens; determination of incidence, inheritance, and nucleolar sizes.

In the chicken, one chromosome pair encodes the ribosomal (r)RNA genes and two nucleoli are formed in interphase cells. The nucleolus is the site of rRNA synthesis and ribosome biogenesis. Nucleolar size polymorphisms have been detected in research strains of chickens and found to represent heterozygosity for rRNA gene copy number. The objectives of the present study were to determine whether nucleolar size polymorphisms exist in commercial chicken flocks and whether such polymorphisms are under genetic control. The occurrence of nucleolar size polymorphisms was studied in three lines of commercial layer chickens (designated A, B, and C). Nucleolar size polymorphisms were found in all three lines. However, the lines differed in the proportion of individuals exhibiting the polymorphic phenotype of two unequal-sized nucleoli (2P). The 2P phenotype, determined in successive years, was found in 10 to 14% of Line A birds, 18 to 23% of Line B birds, and 41 to 63% of Line C birds. The inheritance pattern of the nucleolar size polymorphism and nucleoli sizes were studied in Line C birds. The 2P phenotype was found to be inherited in Mendelian fashion. The large nucleolus was 1.7x and 1.6x that of the smaller nucleolus in 2P males and females, respectively, and was larger than the nucleoli of 2E birds (2E = nonpolymorphic phenotype of two equal-sized nucleoli). Total nucleolar size was greater in cells of 2P birds than in cells of 2E birds. These data suggest that the genetic basis for the large nucleolus in Line C 2P cells is a "larger than normal" rDNA cluster.

Animals↗

PubMed2006

Association of H pylori cagA and vacA genotypes and IL-8 gene polymorphisms with clinical outcome of infection in Iranian patients with gastrointestinal diseases.

AIM: To find out if a functional promoter polymorphism in the IL-8 gene along with cagA status and polymorphisms in vacA gene influence the type of diseases in Iranian patients infected by H pylori. METHODS: IL-8 -251 A/T polymorphism was genotyped by oligonucleotide allele specific PCR (ASO-PCR) in a sample of 233 patients with H pylori infection undergoing upper gastrointestinal endoscopy. The presence of cagA gene and polymorphisms in vacA gene was also determined by PCR. Association of these genetic polymorphisms with the development of gastritis, peptic ulcers as well as gastric cancer was tested. RESULTS: When the patients with different clinical manifestations were compared according to the presence of cagA gene or various vacA genotypes, only the vacA genotypes were significantly different among gastritis, peptic ulcer and gastric cancer patients (chi 2 = 17.8; P = 0.001). Furthermore, there was a significant difference in the frequency of IL-8 -251 A/T genotypes between patients with gastric cancer and benign diseases (chi 2 = 10.47; P = 0.005). CONCLUSION: The IL-8 -251 A/T polymorphism and the polymorphisms in H pylori vacA gene are involved in limiting the infection outcome to gastritis and peptic ulcer or in favoring cancer onset in Iranian patients.

Adult↗

PubMed2005

Gene polymorphisms of epidermal growth factor receptor and its downstream effector, interleukin-8, predict oxaliplatin efficacy in patients with advanced colorectal cancer.

BACKGROUND: Researchers have recently reported an association between the epidermal growth factor receptor (EGFR) pathway and platinum-chemotherapy sensitivity in cancer patients. The (CA)(n) repeat polymorphism in intron 1 of the EGFR gene has been identified and found to alter EGFR expression in vitro as well as in vivo. A higher number of these CA repeats is associated with lower EGFR levels, whereas a low number of repeats is associated with higher EGFR levels. A second key polymorphism within the EGFR pathway (HER1 R497K) is a single nucleotide change (G-A) in codon 497 of the EGFR gene, which leads to an arginine-lysine substitution in the extracellular domain of subdomain IV. Furthermore, interleukin-8 (IL-8), recently identified as an EGFR downstream effector, plays a vital role in tumor angiogenesis and progression. Three other polymorphisms, each related to the IL-8 gene, have also been identified as playing a pivotal role in the EGFR pathway: T-251A in the promoter region of the IL-8 gene, G+2607C in exon 2 of the IL-8 receptor CXCR1 gene, and C+785T in exon 11 of the IL-8 receptor CXCR2 gene. PATIENTS AND METHODS: In this study, we employed a 5'-end 33P-gATP-labeled polymerase chain reaction (PCR) protocol as well as the PCR-restriction fragment length polymorphism method in order to determine the genotypes for the previously mentioned polymorphisms in 105 patients with metastatic colorectal cancer. Tests were conducted to establish whether these polymorphisms could predict clinical outcome to 5-flourouracil/oxaliplatin chemotherapy. RESULTS: Among all patients assessed, those possessing < 20 EGFR CA repeats were more likely to show disease progression than were patients with >or= 20 CA repeats (P = 0.019; log-rank test). Also, patients with the CXCR1 GC genotype were found to have an increased relative risk of time to tumor progression that was 1.55 (95% CI, 0.8-3.0) times that of patients with the homozygous GG genotype (P = 0.17; log-rank test). CONCLUSION: Overall, our data suggest that gene polymorphisms active in the EGFR pathway may be associated with the sensitivity of colorectal cancer patients to platinum-based chemotherapy.

Adult↗

PubMed2002

Interleukin-1 gene polymorphism disease activity and bone mineral metabolism in rheumatoid arthritis.

OBJECTIVE: To determine whether interleukin-1 alpha and 1 beta gene polymorphism is associated with rheumatoid arthritis disease activity and bone mineral metabolism, and whether there is any relationship between IL-1 beta and rheumatoid arthritis (RA) motif gene. METHODS: IL-1 gene polymorphisms were analyzed in 65 RA patients who met American College of Radiology (ACR) criteria and 60 controls. From genomic DNA, 2 polymorphisms in each gene for IL1 alpha-889 and IL-1 beta + 3953 were typed by PCR-RFLP and HLA-DRB1 allele typing was also undertaken by PCR-SSOP. Some clinical and laboratory parameters were collected. The allelic frequencies and carriage rates were compared between RA patients and controls and between patients with active and quiescent disease. Comparison was also made between IL-1 polymorphism and parameters of bone mineral metabolism and between patients with the HLA-DRB1 RA motif plus IL-1 beta 2 and patients without the two alleles. Fisher test and the analysis of variance was used to analyze the data. RESULTS: There was no significant difference in the frequency and carriage rate of IL-1 alpha polymorphisms between RA patients and the controls. The beta 2/2 genotype of IL-1 beta was more common in female RA patients compared with controls (P = 0.001). A lower carriage rate of IL-1 beta 2 occurred in male RA patients (P = 0.001). A higher carriage rate of IL-1 alpha 2 is associated with a higher ESR (P = 0.008), HAQ score (P = 0.03), and vit-D3 (P < 0.001), but conversely a lower SJC (p = 0.002), a lower RF (P = 0.002) and a lower BMD at the lumbar spine (P = 0.001). A higher frequency of IL-1 alpha 1 is associated with a lower CRP value (P = 0.009). An increased IL-1 beta 2 carriage is associated with active rheumatoid disease as indicated by a higher CRP (P < 0.001), ESR (P < 0.001) and pain score (P = 0.001) and a higher BMD at the lumbar spine (P = 0.007), lower vit-D3 and. Udpd/Crea level The presence of the HLA DRB1 RA motif and IL-1 beta allele 2 at same time did not contribute to disease activity. CONCLUSION: Polymorphisms of the IL-beta gene may affect the RA occurrence. Carriage of IL-1 beta 2 polymorphisms is associated with more active disease in RA and the presence of both the IL-1 alpha 2 and the IL-1 beta 1 allele in RA influences bone resorption.

Alleles↗

PubMed2001

Technical note: linkage disequilibrium and disease-associated CTLA4 gene polymorphisms.

CTLA4 and CD28 are important regulators of T lymphocyte activation. Gene region 2q33 carrying genes for both CTLA4 and CD28 has been shown to be linked to many autoimmune diseases. Disease associations with particular CTLA4 gene polymorphisms have been reported. Recently, first lines of evidence emerged for functional effects of CTLA4 gene polymorphisms. Two independent studies reported a reduced inhibitory function of CTLA4 in individuals with certain CTLA4 genotypes: those with a high number of microsatellite repeats in one study and those with allele +49*G in exon 1 in the other one. We analyzed the strength of linkage disequilibrium between the three known CTLA4 polymorphisms among 577 independent chromosomes. Our results show that the polymorphisms previously suggested to be the functional risk factors nearly always occur together in a very frequent haplotype. Due to this strong linkage disequilibrium, we conclude that the previous reports studying merely a single polymorphism could not distinguish which variation actually caused the functional difference. Hence, either mutagenesis approaches or studies with data on all linked polymorphisms are still needed to determine the genuine functional risk polymorphism in this gene region.

Abatacept↗