Association of a T29-->C polymorphism of the transforming growth factor-beta1 gene with genetic susceptibility to myocardial infarction in Japanese

Transforming Growth Factor- β 1 Gene Polymorphism (T29C) in Egyptian Patients with Hepatitis B Virus Infection: A Preliminary Study

The interindividual variations in the capacity of transforming growth factor-β1 (TGF-β1) production have been ascribed to genetic polymorphisms in TGF-β1 gene. As pathogenesis of HBV has a genetic background, this preliminary study was designed to assess the impact of TGF-β1 (T29C) on the susceptibility of Egyptians to HBV infection. Genotyping was performed using single stranded polymorphism-polymerase chain reaction (SSP-PCR) in 65 Egyptian hepatitis B patients and 50 healthy controls. TGF-β1 plasma levels were measured using Enzyme-linked immunosorbent assay (ELISA). The frequency of CC genotype was significantly higher (P < 0.05) in HBV patients compared to controls. On the contrary, TC genotype did not show significant difference in both groups. TT genotype was significantly higher (P < 0.01) in controls than HBV patients. Our current preliminary data revealed that the frequency of the genotypes in the controls were within Hardy-Weinberg equilibrium (HWE) while the patients group was out of HWE (P < 0.01). TGF-β1 was significantly (r = −0.684; P < 0.001) deceased in the sera of patients as compared to normal subjects. Depending on our preliminary work, CC genotype may act as a host genetic factor in the susceptibility to HBV infection in Egyptians. Taken together, the current data pointed to the importance of polymorphism of TGF-β1 gene (T29C) in HBV infection.

TheTGFB1 functional polymorphism rs1800469 and susceptibility to atrial fibrillation in two Chinese Han populations

Transforming growth factor-β1 (TGF-β1) is related to the degree of atrial fibrosis and plays critical roles in the induction and perpetuation of atrial fibrillation (AF). To investigate the association of the common promoter polymorphism rs1800469 in the TGF-β1 gene (TGFB1) with the risk of AF in Chinese Han population, we carried out a case-control study of two hospital-based independent populations: Southeast Chinese population (581 patients with AF and 723 controls), and Northeast Chinese population (308 AF patients and 292 controls). Two hundred and seventy-eight cases of AF were lone AF and 334 cases of AF were diagnosed as paroxysmal AF. In both populations, AF patients had larger left atrial diameters than the controls did. The rs1800469 genotypes in the TGFB1 gene were determined by polymerase chain reaction-restriction fragment length polymorphism. The genotype and allele frequencies of rs1800469 were not different between AF patients and controls of the Southeast Chinese population, Northeast Chinese population, and total Study Population. After adjustment for age, sex, hypertension and LAD, there was no association between the rs1800469 polymorphism and the risk of AF under the dominant, recessive and additive genetic models. Similar results were obtained from subanalysis of the lone and paroxymal AF subgroups. Our results do not support the role of the TGFB1 rs1800469 functional gene variant in the development of AF in the Chinese Han population.

The association between the C-509T and T869C polymorphisms of TGF-β1 gene and the risk of asthma: a meta-analysis

Asthma is a complex multigenic disease in which gene-environment interactions play a critical role in disease onset and progression. Transforming growth factor-β1 (TGF-β1) is one of several candidate locus for the pathogenesis of asthma, and is highly polymorphic. To derive a more precise estimation of the relationship between the T869C and C-509T polymorphisms of the TGF-β1 gene and asthma, a meta-analysis of 24 published case-control studies was conducted. 20 studies for C-509T polymorphism and 8 studies for T869C polymorphism were included. The pooled odds ratios were calculated respectively for allele contrasts, additive genetic model, dominant genetic model and recessive genetic model. Subgroup analyses were also performed by ethnicity, age, atopic status and asthma severity for two gene polymorphisms. In regard to T869C polymorphism, significant associations with asthma were observed in recessive (OR 1.23, 95%CI 1.00-1.51 and P=0.047), additive and allele models. In the subgroup analysis by age, significant risks were also found in the recessive model for adults (OR 1.31, 95%CI 1.02-1.69 and P=0.032), atopic asthma (OR 1.63, 95%CI 1.07-2.49 and P=0.023). With respect to C-509T polymorphism, significant associations with asthma were demonstrated in the overall analysis and subgroup analyses in the dominant model for Asian (OR 1.37, 95%CI 1.04-1.81 and P=0.025), Adults (OR 1.26, 95%CI 1.02-1.56 and P=0.035), Children (OR 1.19, 95%CI 1.01-1.40 and P=0.034). Potentially functional TGF-β1 C-509T and T869C polymorphisms may be risk factors for asthma susceptibility.

Strong impact of TGF-β1 gene polymorphisms on breast cancer risk in Indian women: a case-control and population-based study

Introduction

TGF-β1 is a multi-functional cytokine that plays an important role in breast carcinogenesis. Critical role of TGF-β1 signaling in breast cancer progression is well documented. Some TGF-β1 polymorphisms influence its expression; however, their impact on breast cancer risk is not clear.

Methods

We analyzed 1222 samples in a candidate gene-based genetic association study on two distantly located and ethnically divergent case-control groups of Indian women, followed by a population-based genetic epidemiology study analyzing these polymorphisms in other Indian populations. The c.29C>T (Pro10Leu, rs1982073 or rs1800470) and c.74G>C (Arg25Pro, rs1800471) polymorphisms in the TGF-β1 gene were analyzed using direct DNA sequencing, and peripheral level of TGF-β1 were measured by ELISA.

Results

c.29C>T substitution increased breast cancer risk, irrespective of ethnicity and menopausal status. On the other hand, c.74G>C substitution reduced breast cancer risk significantly in the north Indian group (p = 0.0005) and only in the pre-menopausal women. The protective effect of c.74G>C polymorphism may be ethnicity-specific, as no association was seen in south Indian group. The polymorphic status of c.29C>T was comparable among Indo-Europeans, Dravidians, and Tibeto-Burmans. Interestingly, we found that Tibeto-Burmans lack polymorphism at c.74G>C locus as true for the Chinese populations. However, the Brahmins of Nepal (Indo-Europeans) showed polymorphism in 2.08% of alleles. Mean TGF-β1 was significantly elevated in patients in comparison to controls (p<0.001).

Conclusion

c.29C>T and c.74G>C polymorphisms in the TGF-β1 gene significantly affect breast cancer risk, which correlates with elevated TGF-β1 level in the patients. The c.29C>T locus is polymorphic across ethnically different populations, but c.74G>C locus is monomorphic in Tibeto-Burmans and polymorphic in other Indian populations.

No association between TGFB1 polymorphisms and late radiotherapy toxicity: a meta-analysis

Background

Transforming growth factor-beta 1 (TGF-β1) protein may be multifunctional and related to the development of fibrosis, induction of apoptosis, extracellular signaling and inhibition of proliferation in response to radiation-induced DNA damage. Several studies have investigated associations between single nucleotide polymorphisms (SNPs) in the TGFB1 gene and risk of late radiation-induced injury of normal tissue, but the conclusions remain controversial.

Methods

We searched three electronic databases (i.e., MEDLINE, EMBASE and EBSCO) for eligible publications and performed a meta-analysis assessing the association of three commonly studied SNPs in TGFB1 (i.e., rs1800469, rs1800470 and rs1800471) with risk of late radiation-induced injury of normal tissue.

Results

We finally included 28 case-only studies from 16 publications on aforementioned SNPs in TGFB1. However, we did not find statistical evidence of any significant association with overall risk of late radiotherapy toxicity in the pooled analysis or in further stratified analysis by cancer type, endpoint, ethnicity and sample size.

Conclusions

This meta-analysis did not find statistical evidence for an association between SNPs in TGFB1 and risk of late radiation-induced injury of normal tissue, but this finding needs further confirmation by a single large study.

Genes involved in innate immunity associated with asbestos-related fibrotic changes

Objectives

To determine whether genetic polymorphisms in several candidate genes related to innate immunity and protease–antiprotease balance modify individual susceptibility to develop asbestos-related fibrotic pleuropulmonary changes.

Methods

Sixteen polymorphisms from nine genes (NLRP3, CARD8, TNF, TGFB1, GC, MMP1, MMP9, MMP12 and TIMP2) were genotyped from 951 Finnish asbestos-exposed workers. The genotype/haplotype data were compared to signs of fibrosis and pleural thickenings using linear and logistic regression analysis adjusted for potential confounders.

Results

A functional polymorphism (Q705K; rs35829419) in the NLRP3 gene was associated with interstitial lung fibrosis (p=0.013), and the TGFB1 rs2241718 SNP with visceral pleural fibrosis (VPF) (p=0.044). In stratified analysis, the carriage of at least one NLRP3 variant allele conferred a 2.5-fold increased risk for pathological interstitial lung fibrosis (OR 2.44, 95% CI 0.97 to 6.14). Conversely, the carriage of at least one TGFB1 rs2241718 variant allele protected against VPF (OR 0.62, 95% CI 0.39 to 0.98). The TIMP2 rs2277698 SNP and a haplotype consisting of the TGFB1 rs1800469 and rs1800470 SNPs were associated with the degree of pleural thickening calcification (p=0.037 and p=0.035), and the CARD8 rs2043211 SNP with the greatest thickness of pleural plaques (p=0.015).

Conclusions

Our results support the hypothesis that the NLRP3 inflammasome is important in the development of fibrotic lung disease by associating the NLRP3 rs35829419 variant allele with increased risk of asbestos-related interstitial lung fibrosis, and the TGFB1 rs2241718 variant allele with decreased risk of asbestos-related VPF. Polymorphisms in CARD8 and TIMP2 are proposed to modify the development and/or calcification of pleural thickenings.

Contribution of genetics and epigenetics to progression of kidney fibrosis

Chronic kidney disease (CKD) which can lead to end-stage renal failure remains a principal challenge in Nephrology. While mechanistic studies provided extensive insights into the common pathways of fibrogenesis which underlie the progression of CKD, these pre-clinical studies fail to fully explain the vastly different progression slopes of individual patients. Recent studies provide evidence that genetic polymorphisms and epigenetic variations determine the individual susceptibility of patients to develop chronic progressive kidney disease. Here, we review recent insights that were provided by genome-wide association studies (GWASs), gene-linkage studies and epigenome analysis. The progression of CKD towards end-stage renal failure remains a principal unsolved problem in Nephrology as effective therapies and predictive tests are still not available [ 1, 2]. Chronic progressive kidney disease is caused by a wide range of diseases, with diabetes mellitus, hypertension and primary glomerulopathies being the most common causes in the Western world [ 3]. Infections, physical obstruction, interstitial nephritides and genetic cystic kidney diseases are also common causes of end-stage renal disease (ESRD) [ 3]. Regardless of the primary underlying disease, chronically injured kidneys are histomorphologically characterized by tubulointerstitial fibrosis [ 1]. In fact, the extent of tubulointerstitial fibrosis is the best predictor for kidney survival, irrespective of the underlying disease. For this reason, fibrosis is considered the common pathway of chronic progressive kidney disease [ 1]. Fibrogenesis is a pathological scarring process which involves accumulation of activated fibroblasts, excessive deposition of extracellular matrix, failed regeneration of tubular epithelium, microvascular rarefaction and (mostly sterile) inflammation [ 4]. Fibrogenesis depends on a complex interaction of the involved cell types which is orchestrated by an extensive network of growth factors and signalling pathways (which are reviewed extensively elsewhere) [ 1]. In view of the detailed mechanistic knowledge of the pathways that orchestrate renal fibrogenesis, it is puzzling why progression rates of CKD differ dramatically among patients with identical underlying diseases [ 1, 2]. The fibrotic pathways are known, but the switches that control their intensities and which determine the speed at which fibrosis moves along the progression slope are not yet understood [ 1, 2]. The concept that genetic polymorphisms are the basis for individual progression rates of CKD is an obvious and attractive one. Distinct susceptibilities of different mouse and rat strains to experimental CKD are a strong testament of the impact of genetic variations on renal fibrogenesis. Identification of the underlying genetic polymorphisms and mechanistic proof of their involvement in the progression of CKD, however, is an ongoing challenge. There are two basic approaches: one strategy is to perform unbiased screening to identify genes which are associated with chronic progressive kidney disease and to then prove their mechanistic relevance in experimental studies ('genotype to phenotype approach'). The second strategy is to selectively analyse polymorphisms of genes which have been identified in mechanistic studies as drivers of renal fibrogenesis with regard to their association with CKD (phenotype to genotype approach). The puzzling observation, however, is that genetic analysis and mechanistic studies so far rarely complement each other. The current state of affairs is reviewed in more detail below.

Role of non-HLA gene polymorphisms in graft-versus-host disease

A large number of reports have associated various non-HLA gene polymorphisms with the risk and severity of graft-versus-host disease (GVHD). To date, candidate gene studies and genome-wide association studies have been performed to investigate such non-HLA gene polymorphisms in relation to GVHD. Candidate gene studies are hypothesis-driven and cost-effective, whereas genome-wide association studies have the potential to discover new gene polymorphisms, including possible biomarkers and therapeutic targets. Some gene polymorphisms have the potential to affect protein function or gene expression, or to encode minor histocompatibility antigens. Non-HLA genotyping for genes influencing GVHD prior to transplantation should provide useful information that will facilitate choosing the donor, type of graft, conditioning treatment, and GVHD prophylaxis. However, attention should be paid to the need for validation studies and ethical issues.

The L10P polymorphism and serum levels of transforming growth factor β1 in human breast cancer

The L10P single nucleotide polymorphism (SNP) is located in the signal sequence of the transforming growth factor β1 (TGFβ1) gene. The proline-encoding (Pro-) allele of this SNP has been associated with an increased breast cancer risk, which has been attributed to the elevated secretion of this TGFβ1 variant observed in vitro and in male subjects. Here we investigated the association of the L10P SNP with serum levels of TGFβ1 in female breast cancer patients and controls. We genotyped the L10P SNP in 276 breast cancer patients and 255 controls. Serum TGFβ1 concentrations were measured by enzyme-linked immunosorbent assay (ELISA) in a subset of the study population (n = 211). We found no evidence for an association of the L10P SNP with breast cancer risk (per-allele odds ratio: 0.91; 95% confidence interval: 0.71-1.16). However, patients with the Pro/Pro genotype exhibited a significantly younger age at breast cancer onset (55.2 ± 14.3 years) than Leu/Leu patients (60.6 ± 13.6 years; p = 0.04), which may reflect the ability of TGFβ to promote tumor progression. Mean TGFβ1 serum levels of Pro-allele carriers were 39.4 ± 7.4 ng/mL, whereas those of Leu/Leu subjects were 37.6 ± 6.0 ng/mL (p = 0.07). Thus, compared to a previous study of male subjects, we observed only a modest increase, if any, in TGFβ1 levels of female Pro-allele carriers.

TGF-β signalling and its role in cancer progression and metastasis

The transforming growth factor-β (TGF-β) system signals via protein kinase receptors and SMAD mediators to regulate a large number of biological processes. Alterations of the TGF-β signalling pathway are implicated in human cancer. Prior to tumour initiation and early during progression, TGF-β acts as a tumour suppressor; however, at later stages, it is often a tumour promoter. Knowledge about the mechanisms involved in TGF-β signal transduction has allowed a better understanding of cancer progression, invasion, metastasis and epithelial-to-mesenchymal transition. Furthermore, several molecular targets with great potential in therapeutic interventions have been identified. This review discusses the TGF-β signalling pathway, its involvement in cancer and current therapeutic approaches.

Association of rs1800471 polymorphism of TGFB1 gene with chronic kidney disease occurrence and progression and hypertension appearance

INTRODUCTION

Transforming growth factor β1 (TGF-β1) is a cytokine involved in the process of pathological tissue sclerosis, which is part of the pathophysiological mechanism of end stage renal disease development. The aim of the study was to evaluate the association of the single nucleotide polymorphism rs1800471 of the TGFB1 gene with chronic kidney disease (CKD) occurrence and progression as well as hypertension appearance.

MATERIAL AND METHODS

It was a case-control study where 109 patients with CKD and 111 very old people were enrolled. The association of the studied polymorphism with mentioned diseases was assessed in the whole study group as well as in the subgroups stratified according to the underlying etiology of CKD: nephropathy in type 1 diabetes (n = 13), chronic glomerulonephritis (n = 50) and chronic interstitial nephritis (n = 46).

RESULTS

No association of CKD progression with rs1800471 polymorphism was observed. The C allele was identified as the one associated with higher risk of the disease occurrence in the dominant model of inheritance (p = 0.035). The C allele in women, opposite to male gender, was associated with higher risk of CKD development (p = 0.038). GG genotype was associated with elevated risk of hypertension appearance (p = 0,0021).

CONCLUSIONS

Due to the lack of accordance with previously performed studies it is still impossible to state an unequivocal conclusion regarding the association between rs1800471 polymorphism of the TGFB1 gene and risk of CKD occurrence and progression as well as hypertension appearance. That is why it is necessary to perform further studies in this field.

Cytokine Polymorphisms, Their Influence and Levels in Brazilian Patients with Pulmonary Tuberculosis during Antituberculosis Treatment

Cytokines play an essential role during active tuberculosis disease and cytokine genes have been described in association with altered cytokine levels. Therefore, the aim of this study was to verify if IFNG, IL12B, TNF, IL17A, IL10, and TGFB1 gene polymorphisms influence the immune response of Brazilian patients with pulmonary tuberculosis (PTB) at different time points of antituberculosis treatment (T1, T2, and T3). Our results showed the following associations: IFNG +874 T allele and IFNG +2109 A allele with higher IFN-γ levels; IL12B +1188 C allele with higher IL-12 levels; TNF −308 A allele with higher TNF-α plasma levels in controls and mRNA levels in PTB patients at T1; IL17A A allele at rs7747909 with higher IL-17 levels; IL10 −819 T allele with higher IL-10 levels; and TGFB1 +29 CC genotype higher TGF-β plasma levels in PTB patients at T2. The present study suggests that IFNG +874T/A, IFNG +2109A/G, IL12B +1188A/C, IL10 −819C/T, and TGFB1 +21C/T are associated with differential cytokine levels in pulmonary tuberculosis patients and may play a role in the initiation and maintenance of acquired cellular immunity to tuberculosis and in the outcome of the active disease while on antituberculosis treatment.

Genetic variation in TGFB1 gene and risk of idiopathic recurrent pregnancy loss

Transforming growth factor β1 plays a significant role in pregnancy outcome. We investigated the association of TGFB1 exon 1 (rs1800471, rs1800470) and promoter region (rs1800469, rs1800468) polymorphisms with recurrent pregnancy loss (RPL) in 675 Tunisian women: 304 women with a history of three consecutive pregnancy losses of unknown etiology with the same partner and 371 age-matched multiparous control women. TGFB1 genotyping was done by TaqMan assays. Higher minor allele frequency for rs1800471 (P< 0.001), but not for rs1800470, rs1800469 or rs1800468 was found in RPL cases compared with controls. A significant difference in the distribution of rs1800471 genotypes was seen between the RPL cases and control women, irrespective of the genetic model used. Increased RPL risk was seen with rs1800471 allele C in the heterozygous state and to a greater degree in the homozygous state, thus establishing a dose-dependent effect. Haploview analysis revealed differential linkage disequilibrium between the TGFB1 single-nucleotide polymorphisms analyzed. TGFB1 haplotype analysis identified eight common haplotypes (rs1800471/rs1800470/rs1800469/rs1800468) with three (GTTG, Pc = 0.02; CCTG, Pc = 0.02 and CTCG, Pc = 0.02) positively associated with RPL and one (GCCG, Pc = 0.009) negatively associated with RPL. This study provides the first evidence that the TGFB1 genotype may influence RPL.

Genetic variation in transforming growth factor beta 1 and mammographic density in Singapore Chinese women

TGF-β plays a critical role in normal mammary development and morphogenesis. Decreased TGF-β signaling has been associated with increased mammographic density. Percent mammographic density (PMD) adjusted for age and body mass index (BMI) is a strong risk factor and predictor of breast cancer risk. PMD is highly heritable, but few genetic determinants have been identified. We investigated the association between genetic variation in TGFB1 and PMD using a cross-sectional study of 2,038 women who were members of the population-based Singapore Chinese Health Study cohort. We assessed PMD using a computer-assisted method. We used linear regression to examine the association between nine tagging single-nucleotide polymorphisms (SNP) of TGFB1 and PMD and their interaction with parity, adjusting for age, BMI, and dialect group. We calculated P values adjusted for correlated tests (P(ACT)) to account for multiple testing. The strongest association was observed for rs2241716. Adjusted PMD was higher by 1.5% per minor allele (P(ACT) = 0.04). When stratifying by parity, this association was limited to nulliparous women. For nulliparous women, adjusted PMD was higher by 8.6% per minor allele (P(ACT) = 0.003; P for interaction with parity = 0.002). Three additional TGFB1 tagging SNPs, which were in linkage disequilibrium with rs2241716, were statistically significantly associated with adjusted PMD (P(ACT) < 0.05) for nulliparous women. However, none of these three SNPs showed statistically significant association after adjusting for rs2241716. Our data support that TGFB1 genetic variation may be an important genetic determinant of mammographic density measure that predicts breast cancer risk, particularly in nulliparous women.

Transforming growth factor beta1 gene variation Leu10Pro affects secretion and function in hepatic cells

BACKGROUND

Our previous work revealed transforming growth factor beta1 (TGFβ1) gene polymorphisms are associated with susceptibility to hepatocellular carcinoma and liver cirrhosis. However, no further study of functional substitution in hepatic cells has yet been reported.

AIMS

This study was designed to uncover the functional mechanisms of TGFβ1 gene polymorphisms in the pathogenesis of liver diseases.

METHODS

Two recombinant TGFβ1 expression plasmids containing TGFβ1 codon 10 Leu/Pro variation were constructed with CMV promoter and transfected into human hepatoma cell lines (HepG2 and SMMU 7721), hepatic stellate cells (LX-2), and immortalized hepatocytes (L02). The secretion capacities of TGFβ1 protein in the transfected cells were determined by ELISA. Apoptosis, proliferative activity, and expression of CD 105, CD83, and CD80 were also measured by use of flow cytometry.

RESULTS

The ELISA results showed that cells transfected with CMV-Pro10 were more capable of TGFβ1 secretion than those transfected with CMV-Leu10. Functionally, CMV-Pro10 was more apoptosis-protective and induced more proliferation than CMV-Leu10 in transfected hepatic cells. Pro10 up-regulated expression of CD105 and down-regulated expression of CD83.

CONCLUSIONS

TGFβ1 gene Leu10Pro variation in signal peptide has significant effects on TGFβ1 secretion and functions in hepatic cells.

The haplotype of the TGFβ1 gene associated with cerebral infarction in Chinese

BACKGROUND

Transforming growth factor beta1 (TGFβ1) is a multifunctional cytokine involved in inflammation and pathogenesis of atherosclerosis. The aim of the present study was to investigate the relationship between human TGFβ1 gene +869T>C (rs1800470), -509C>T (rs1800469) single nucleotide polymorphisms (SNPs) and haplotypes and cerebral infarction (CI) in a Chinese population.

METHODS

The genetic association study was performed in 450 Chinese patients (306 male and 144 female) with CI and 450 control subjects (326 male and 124 female). TGFβ1 gene +869T>C and -509C>T polymorphisms were identified with amplification refractory mutation system polymerase chain reaction and DNA sequencing method.

RESULTS

The individual SNPs analysis showed the +869T and -509C in an additive model (+869T vs +869C; -509 C vs T), +869TT genotype in a recessive model (TT vs TC+CC) and 509CC genotype in a dominant model (CC+ CT vs TT) were identified to be related to CI (P<0.05). +869T>C and -509C>T SNPs were in strong linkage disequilibrium (d'=0.87, R2=0.75). Haplotype analysis showed that +869C/-509T haplotype was associated with a significant decreased risk of CI (OR= 0.86, 95%CI, 0.70-0.92; P=0.007). Furthermore,+869T/-509C haplotype was associated with a significant increased risk of CI (OR=1.31, 95%CI, 1.10-2.03; P=0.019).

CONCLUSIONS

The results of this study indicate that polymorphisms and the haplotypes in the TGFβ1 gene might be genetic markers for CI in the Chinese population.

TGF-β polymorphism and its expression correlated with CXCR4 expression in human breast cancer

The role of chemokines and the growth factors has been extensively analyzed both in cancer risk and tumor progression. The transforming growth factor beta (TGF-β) and chemokine (C-X-C motif) receptor 4 (CXCR4) genes are implicated in several diseases, including breast cancer. Genomic DNA was obtained from 21 samples of peripheral blood or from normal tissue, previously fixed in formalin and embedded in paraffin for TGF-β T869C polymorphism analyses. Total cellular RNA was extracted from the same 21 patients, but from fresh tissue (tumor and adjacent healthy from the same breast) for expression analysis by Real Time PCR. No significant differences were observed in genotype distribution according to clinicopathological characteristics. Transforming growth factor beta (TGF-β) mRNA expression was assessed according to T869C polymorphism and CC patients presented a higher TGF-β expression but not significant when compared to other genotypes (p = 0.064). A positive correlation was observed in relative mRNA expressions of CXCR4 and TGF-β (p = 0.020). It is known that overexpression of TGF-β by both tumor and stromal tissue can facilitate the development of metastases, mainly by TGF-β stimulated angiogenesis and increased tumor cell motility. Our findings suggested a role of these genes as progression markers for breast carcinoma.

Meta-analysis of the association between transforming growth factor-beta polymorphisms and complications of coronary heart disease

Objective

To investigate the association between common transforming growth factor beta (TGF-β) single nucleotide polymorphisms (SNP) and significant complications of coronary heart disease (CHD).

Method

We performed a meta-analysis of published case-control studies assessing the association of TGF-β SNPs with a range of CHD complications. A random effects model was used to calculate odds ratios and confidence intervals. Analyses were conducted for additive, dominant and recessive modes of inheritance.

Results

Six studies involving 5535 cases and 2970 controls examining the association of common SNPs in TGF-β1 with CHD were identified. Applying a dominant model of inheritance, three TGF-β1 SNPs were significantly associated with CHD complications: The T alleles of rs1800469 (OR = 1.125, 95% CI 1.016–1.247, p = 0.031) and rs1800470 (OR = 1.146, 95% CI 1.026–1.279, p = 0.021); and the C allele of rs1800471 (OR = 1.207, 95% CI 1.037–1.406, p = 0.021).

Conclusion

This meta-analysis suggests that common genetic polymorphisms in TGF-β1 are associated with complications of CHD.

TGFB1 genetic polymorphisms and coronary heart disease risk: a meta-analysis

BACKGROUND

Genetic variations in TGFB1 gene have been studied in relation to coronary heart disease (CHD) risk, but the results were inconsistent.

METHODS

We performed a systematic review of published studies on the potential role of TGFB1 genetic variation in CHD risk. Articles that reported the association of TGFB1 genetic variants with CHD as primary outcome were searched via Medline and HuGE Navigator through July 2011. The reference lists from included articles were also reviewed.

RESULTS

Data were available from 4 studies involving 1777 cases and 7172 controls for rs1800468, 7 studies involving 5935 cases and 10677 controls for rs1800469, 7 studies involving 6634 cases and 9620 controls for rs1982073, 5 studies involving 5452 cases and 9999 controls for rs1800471, and 4 studies involving 5143 cases and 4229 controls for rs1800472. The pooled odds ratios (ORs) for CHD among minor T allele carriers of rs1800469, minor C allele carriers of rs1982073, and minor C allele carriers of rs1800471 versus homozygous major allele carriers was 1.14 (95% confidence interval [CI]: 1.05-1.24), 1.18 (95% CI: 1.04-1.35), and 1.16 (95% CI: 1.02-1.32), respectively. No substantial heterogeneity for ORs was detected among the included Caucasian populations for all SNPs. However, for rs1800471, the statistical significance disappeared after adjusting for potential publication bias. No significant association was found between rs1800468 and rs1800472 variants and CHD risk.

CONCLUSION

Minor allele carriers of two genetic variants (rs1800469 and rs1982073) in TGFB1 have a 15% increased risk of CHD.

Gene variants in the angiogenesis pathway and prostate cancer

Although the causes of prostate cancer are still unknown, numerous studies support the role of genetic factors in the development and progression of this disease. Single nucleotide polymorphisms (SNPs) in key angiogenesis genes have been studied in prostate cancer. In this review, we provide an overview of the current knowledge of the role of genetic variants in the angiogenesis pathway in prostate cancer risk and progression. Of the 17 prostate cancer genome-wide association studies (GWAS) conducted to date, only one identified disease-associated SNPs in a region of an angiogenesis pathway gene. An association was observed between aggressive disease and three intergenic SNPs (rs11199874, rs10749408 and rs10788165) in a region on chromosome 10q26 that encompasses FGFR2. The majority (27/32, 84.4%) of primary candidate gene studies reviewed had a small (n < 800, 20/32, 62.5%) to medium sample size (n = 800-2000, 7/32, 21.9%), whereas only five (15.6%) had a large sample size (n ≥ 2000). Results from the large studies revealed associations with risk and aggressive disease for SNPs in NOS2A, NOS3 and MMP-2 and risk for HIF1-α. Meta-analyses have so far been conducted on FGFR2, TGF-β, TNF-α, HIF1-α and IL10 and the results reveal an association with risk for SNPs in FGFR2 and TGF-β and aggressive disease for SNPs in IL-10. Thus, existing evidence from GWAS and large candidate gene studies indicates that SNPs from a limited number of angiogenesis pathway genes are associated with prostate cancer risk and progression.

Interaction between smoking and functional polymorphism in the TGFB1 gene is associated with ischaemic heart disease and myocardial infarction in patients with rheumatoid arthritis: a cross-sectional study

INTRODUCTION

Transforming growth factor-beta1 (TGF-beta1) is a pleiotropic cytokine that plays important roles in immunity and inflammation. Some studies have suggested that polymorphism in the TGFB1 gene is associated with heart disease in the general population. The purpose of the present study was to determine whether common single-nucleotide polymorphisms (SNP) in the TGFB1 gene are associated with ischaemic heart disease (IHD) and/or myocardial infarction (MI) in patients with rheumatoid arthritis (RA), and to investigate the influence of smoking on any association.

METHODS

PCR-based assays were used to determine the genotypes of TGFB1 SNPs including TGFB1-509 C/T (rs1800469, in the promoter region), +868 T/C (rs1800470, in exon 1) and +913 G/C (rs1800471, in exon 1) in 414 subjects with established RA. Genotyping for the +868 SNP was also carried out on a second study population of RA patients (n = 259) with early disease. Serum levels of TGF-beta1 were measured using a commercial ELISA kit. Smoking history and IHD/MI status were obtained on each patient. Associations with IHD/MI were assessed using contingency tables and logistic regression analyses.

RESULTS

The heterozygous genotype of TGFB+868 was associated with an increased risk of IHD (OR 2.14, 95% CI 1.30 - 3.55) and MI (OR 2.42, 95% CI 1.30-4.50), compared to the homozygous genotypes combined. Smoking was an independent risk for IHD and MI, and evidence of interaction between smoking and TGFB+868 was found. Multivariate analyses indicated that the strongest associations with IHD and MI were due to the combined effect of the TGFB1+868 TC genotype and smoking (OR 2.75, 95% CI 1.59-4.75; and OR 2.58 95% CI 1.33-4.99, respectively), independent of other cardiovascular risk factors. The association of the +868 TC genotype and evidence of +868 TC-smoking interaction with IHD were replicated in a second population of RA patients with early disease. Serum TGF-beta1 levels were not associated with TGFB1 genetic variations, smoking or IHD/MI status.

CONCLUSIONS

Interaction between smoking and polymorphism in the TGFB1 gene may influence the risk of IHD and MI in patients with RA.

The CC genotype of transforming growth factor-β1 increases the risk of late-onset Alzheimer's disease and is associated with AD-related depression

Transforming growth factor-β1 (TGF-β1) is a neurotrophic factor that exerts neuroprotective effects against β-amyloid-induced neurodegeneration. Recently, a specific impairment of the TGF-β1 signaling pathway has been demonstrated in Alzheimer's disease (AD) brain. TGF-β1 is also involved in the pathogenesis of depressive disorders, which may occur in 30-40% of AD patients. The TGF-β1 gene contains single nucleotide polymorphisms (SNPs) at codon +10 (T/C) and +25 (G/C), which are known to influence the level of expression of TGF-β1. We investigated TGF-β1 +10 (T/C) and +25 (G/C) SNPs and allele frequencies in 131 sporadic AD patients and in 135 healthy age- and sex-matched controls. Genotypes of the TGF-β1 SNPs at codon +10 (T/C) and +25 (G/C) did not differ between AD patients and controls, whereas the allele frequencies of codon +10 polymorphism showed a significant difference (P = 0.0306). We also found a different distribution of the +10 (C/C) phenotype (continuity-corrected χ(2) test with one degree of freedom = 4.460, P = 0.0347) between late onset AD (LOAD) patients and controls (P = 0.0126), but not between early onset AD (EOAD) patients and controls. In addition, the presence of the C/C genotype increased the risk of LOAD regardless of the status of apolipoprotein E4 (odds ratio [OR] = 2.34; 95% CI = 1.19-4.59). Compared to patients bearing the T/T and C/T polymorphisms, LOAD TGF-β1 C/C carriers also showed > 5-fold risk to develop depressive symptoms independently of a history of depression (OR = 5.50; 95% CI = 1.33-22.69). An association was also found between the TGF-β1 C/C genotype and the severity of depressive symptoms (HAM-D(17) ≥ 14) (P < 0.05). These results suggest that the CC genotype of the TGF-β1 gene increases the risk to develop LOAD and is also associated with depressive symptoms in AD.

The T29C polymorphism of the transforming growth factor-β1 (TGF-β1) gene is associated with genetic susceptibility to acute coronary syndrome in Mexican patients

Inflammation plays an essential role in the development and progression of atherosclerotic lesions, and plaque disruption. The TGF-β1 plays an important role in the anti-inflammatory process. The aim of the present study was to evaluate the role of TGF-β1 gene polymorphisms as susceptibility markers for acute coronary syndrome (ACS). Two polymorphisms (TGF-β -509T>C and TGF-β T29C) of the TGF-β gene were analyzed by 5' exonuclease TaqMan genotyping assays in a group of 426 patients with coronary acute syndrome and 551 healthy unrelated controls. A significant difference was observed in the distribution of TGF-β T29C polymorphism between ACS patients and healthy controls (P<10(-3)). According to the co-dominant model, individuals with the TGF-β 29 TT genotype have a 2.5-fold increased risk of developing ACS (P<10(-3)). Multiple logistic analysis showed that the largest risk factor for developing ACS was given by smoking habit, diabetes, hypertension, dyslipidemia, and the TGF-β1 29 TT genotype. The analysis of linkage disequilibrium showed one haplotype (TT) with increased frequency and one haplotype (CC) with decreased frequency in ACS patients when compared to healthy controls. The results suggest that TGF-β1 T29C gene polymorphism could be involved in the risk of developing ACS in Mexican individuals.

TGF-beta 1 codon 10 polymorphism is associated with cerebral SVD

BACKGROUND

To clarify the role of inflammation in the pathogenesis of cerebral small vessel disease (SVD), we investigated whether the gene encoding transforming growth factor-beta 1(TGF-beta 1) is a risk factor for cerebral SVD as a whole, and for two different SVD subtypes.

METHODS

TGF-beta 1 codon10 (T+29C) genotype was determined in 441 Chinese patients (313 male and 128 female) with cerebral SVD and 450 control subjects (326 male and 124 female). Cerebral SVD patients were retrospectively classified into two groups based on neuroimaging findings: lacunar infarction group with 112 patients and ischaemic leukoaraiosis group with 329 patients.

RESULTS

Subjects carrying TT homozygote were susceptible to cerebral SVD [adjusted odds ratio (OR) =1.44, 95% confidence interval (CI), 1.05-1.98; P=0.026]. Further analysis of SVD subtypes revealed a moderate association with the ischaemic leukoaraiosis group [OR= 1.60, 95% CI, 1.14-2.25; P=0.007].

CONCLUSIONS

Codon 10 of TGF-beta 1 might be a risk factor for SVD, specifically in ischaemic leukoaraiosis phenotype.

Association of transforming growth factor-β1 gene polymorphisms with genetic susceptibility to acute myocardial infarction

INTRODUCTION

Transforming growth factor beta 1 (TGF-β1) gene plays an important role in acute myocardial infarction (AMI); however, little is known about the relation of variations within the gene and risk of cardiovascular diseases. In this study, the authors evaluated the influence of TGF-β1 polymorphisms on the onset and progression of AMI in Iranian patients comparing with healthy individuals.

METHODS

Genomic DNA and peripheral blood mononuclear cells of 900 enrolled patients with AMI and 900 control subjects were extracted. The -509 C/T, 868T/C, 913G/C and 11929C/T TGF-β1 polymorphisms were detected. The messenger RNA (mRNA) expression and serum levels of TGF-β1 were analyzed by real-time reverse-transcriptase polymerase chain reaction and ELISA, respectively.

RESULTS

The frequency of "T" allele in -509 C/T, "C" allele in 868T/C, "C" allele in 913G/C and "T" allele in 11929C/T polymorphisms were significantly higher in the patients than control subjects (P < 0.001). There were significant differences in circulating levels of TGF-β1 in the patients than in control subjects (P < 0.001). These concentrations are associated with its gene polymorphism. The mRNA expression levels of TGF-β1 were significantly higher in the patient serums compared with controls (P < 0.001).

CONCLUSIONS

Our results confirmed the association between the TGF-β1 polymorphisms and risk of AMI, which suggest that genetic polymorphisms in TGF-β1 might be helpful for determining susceptibility to AMI in Iranian patients. There are also significant relationship between serum TGF-β1 and occurrence of AMI. In addition, susceptibility to AMI might be related to TGF-β1 gene expression, which affects its serum levels.

Transforming growth factor β1 T868C gene polymorphism is associated with cerebral infarction in Japanese patients with type 2 diabetes

It is likely that the C allele of the polymorphism at position 29 of the translated sequence of transforming growth factor (TGF)-β1 gene, which codes a pleiotropic cytokine expressed in a variety of cells, is a susceptibility allele for cerebral infarction in Japanese type 2 diabetic patients.

Association of 29C>T polymorphism in the transforming growth factor-β1 gene with lean body mass in community-dwelling Japanese population

AIM

Sarcopenia is the significant degenerative loss of skeletal muscle mass and strength associated with aging, and it is one of the components of frailty. We previously reported an association between the 29C>T polymorphism in the transforming growth factor-β1 gene (rs1800470) and the prevalence of vertebral fractures in subjects with postmenopausal osteoporosis. The association was not attributable to bone mineral density, which suggests that polymorphism influences some aspects of bone quality that affects strength and/or frailty rather than bone strength itself. Thus, we examined the relationship between genetic polymorphism and lean body mass in a Japanese population.

METHODS

A total of 479 adults comprising 143 men and 336 women, age 23 to 85 years, participated in the present study. Fat-free mass was measured by dual energy X-ray absorptiometry, and the relative skeletal muscle index was calculated as the ratio of appendicular (sum of arms and legs) fat-free mass to the square of height.

RESULTS

Total, leg, and appendicular fat-free mass as well as the relative skeletal muscle index were significantly lower in male subjects with CT/TT genotypes compared to those with CC genotype. Female subjects did not show any genotype-dependent differences when analyzed as a group, but when those without menstruation (postmenopausal women) were analyzed, arm fat-free mass was significantly lower in the CT/TT genotypes than in the CC genotype.

CONCLUSIONS

T allele of the 29C>T polymorphism in the transforming growth factor-β1 gene might be a risk factor of sarcopenia in a Japanese population.

Genetic polymorphism at codon 10 of the transforming growth factor-β1 gene in patients with alcoholic liver cirrhosis

Background/Aims

Transforming growth factor beta1 (TGF-β1) is a key cytokine in the production of extracellular matrix. A genetic polymorphism at codon 10 of the TGF-β1 gene is associated with liver fibrosis. We investigated the effect of genetic polymorphisms at codon 10 on the development of alcoholic liver cirrhosis (ALC).

Methods

In total, 119 controls and 182 patients with ALC, were enrolled in the study. Clinical and laboratory data including total lifetime alcohol intake were collected at enrollment. The genotype at codon 10 was determined for each patient by single-strand conformation polymorphism.

Results

There were three types of genetic polymorphism at codon 10: homozygous proline (P/P), heterozygous proline/leucine (P/L), and homozygous leucine (L/L). Among the controls, the proportions of P/P, P/L, and L/L were 26.1%, 44.5%, and 29.4%, respectively in the ALC group, these proportions were 23.1%, 43.4%, and 33.5%, respectively. The genotype distribution did not differ between the controls and the ALC group. In the ALC group, age, total lifetime alcohol intake, and distribution of Child-Pugh class did not differ with the genotype. Of the male patients with ALC (n=164), the proportions of P/P, P/L, and L/L were 20.1%, 44.5%, and 35.4%, respectively the genotype distribution did not differ between the male controls and the male ALC patients.

Conclusions

The genotype at codon 10 in TGF-β1 does not appear to influence the development of ALC. Further study is needed to investigate other genetic factors that influence the development of ALC in patients with chronic alcohol intake.

Association of transforming growth factor-β1 gene C-509T and T869C polymorphisms with atherosclerotic cerebral infarction in the Chinese: a case-control study

Background

Transforming growth factor-β1 (TGF-β1) is a multifunctional cytokine involved in inflammation and pathogenesis of atherosclerosis. There is scant information on the relation between variations within the TGF-β1 gene polymorphisms and risks of ischemic cerebrovascular diseases. Therefore, this case-controlled study was carried out to investigate the possible association of the TGF-β1 gene C-509T and T869C polymorphisms, and their combined genotypes with the risk of atherosclerotic cerebral infarction (CI) in the Chinese population.

Results

We recruited 164 CI patients and 167 healthy control subjects who were frequency-matched for age and gender. The frequencies of the -509TT genotype and T allele gene were significantly higher in the CI group (P = 0.007, P = 0.006). The frequencies of +869CC genotype and C allele were higher in the CI group (P = 0.002, P = 0.004). In the CI group, the individuals with -509TT genotype had a significantly higher level of plasma triglyceride (TG) (P = 0.017). +869CC genotype correlated significantly with higher level of plasma low density lipoprotein cholesterol (LDL-c) in the CI group (P = 0.015). With haplotype analysis, the frequency of the -509T/+869C combined genotype was significantly higher in the CI group than in controls (P < 0.001).

Conclusions

Our study suggests that C-509T and T869C gene polymorphisms in TGF-β1 may be a critical risk factor of genetic susceptibility to CI in the Chinese population.

TGF-β1 869T/C polymorphism and ischemic stroke: sex difference in Chinese

BACKGROUND

Inflammation plays a pivotal role in the pathogenesis of atherosclerosis and of cerebrovascular complications. Transforming growth factor-β (TGF-β) is a pleiotropic cytokine with a central role in inflammation. To investigate whether polymorphisms of the TGF-β1 gene can modify the risk of ischemic stroke (IS) in Chinese population, we conduct this hospital-based, case-control study.

METHODS

Transforming growth factor-β1 genotype was determined in 450 Chinese patients (306 male and 144 female) with IS and 450 control subjects (326 male and 124 female).

RESULTS

Subjects carrying 869TT were susceptible to IS (odds ratio [OR] =1.58; P=0.003). Further analysis of IS data partitioned by gender revealed the female-specific association with 869T/C (OR=2.64; P=0.001).

CONCLUSIONS

Findings suggest that the TT genotype of 869T/C might be a risk factor of IS in Chinese, especially in females.

A putatively functional haplotype in the gene encoding transforming growth factor beta-1 as a potential biomarker for radiosensitivity

PURPOSE

To determine whether genetic variability in TGFB1 is related to circulating transforming growth factor-β1 (TGF-β1) plasma concentrations after radiotherapy and to radiosensitivity of lymphoid cells.

PATIENTS AND METHODS

Transforming growth factor-β1 plasma concentrations (n=79) were measured in patients 1 year after radiotherapy and chromosomal aberrations (n=71) ex vivo before therapy start. Furthermore, TGF-β1 secretion and apoptosis were measured in isolated peripheral blood mononuclear cells of 55 healthy volunteers. These phenotypes were analyzed in relation to five germline polymorphisms in the 5' region of the TGFB1 gene. Because of high linkage disequilibrium, these five polymorphisms reflect frequent genetic variation in this region. A presumed impact of TGF-β1 on DNA damage or repair was measured as micronucleus formation in 30 lymphoblastoid cell lines.

RESULTS

We identified a hypofunctional genetic haplotype termed H3 tagging the 5' region of the TGFB1 gene encoding TGF-β1. H3 was associated with lower TGF-β1 plasma concentrations in patients (p=0.01) and reduced TGF-β1 secretion in irradiated peripheral blood mononuclear cells (p=0.003). Furthermore, cells with H3 were less prone to induction of chromosomal aberrations (p=0.001) and apoptosis (p=0.003) by irradiation. The hypothesis that high TGF-β1 could sensitize cells to DNA damage was further supported by increased micronuclei formation in 30 lymphoblastoid cell lines when preincubated with TGF-β1 before irradiation (p=0.04).

CONCLUSIONS

On the basis of TGF-β1 plasma levels and radiation sensitivity of lymphoid cells, this study revealed a putatively hypofunctional TGFB1 haplotype. The significance of this haplotype and the suggested link between TGF-β1 function and DNA integrity should be further explored in other cell types, as well as other experimental and clinical conditions.

Influence of thyroid hormones and transforming growth factor-β1 on cystatin C concentrations

Serum cystatin C concentrations are reported to increase in the hyperthyroid state. Serum concentrations of cystatin C and transforming growth factor-β1 (TGF-β1) were measured in patients with thyroid dysfunction, and the effects of 3,5,3'-tri-iodothyronine (T(3)) and TGF-β1 on cystatin C production in human hepatoblastoma (Hep G2) cells were studied. Serum concentrations of cystatin C and TGF-β1 were significantly higher in patients with Graves' disease compared with control subjects. Significantly positive correlations were observed between thyroid hormones and cystatin C, thyroid hormones and TGF-β1, and TGF-β1 and cystatin C in patients with thyroid dysfunction. Serum concentrations of cystatin C and TGF-β1 decreased after treatment for hyperthyroidism. Cystatin C mRNA levels and cystatin C secretion were increased by T(3) and TGF-β1 in cultured Hep G2 cells. These results suggest that serum cystatin C concentrations increase in patients with hyperthyroidism. The mechanisms for this may involve elevation of serum TGF-β1 levels and the stimulatory effects of T(3) and TGF-β1 on cystatin C production.

A polymorphism in transforming growth factor-β1 is associated with carotid plaques and increased carotid intima-media thickness in older Chinese men: the Guangzhou Biobank Cohort Study-Cardiovascular Disease Subcohort

OBJECTIVE

Polymorphisms of the transforming growth factor-β1 (TGFB1) gene have not been associated with asymptomatic atherosclerosis previously. We investigated the relationship between a single nucleotide polymorphism (SNP) rs4803455 in TGFB1 and atherosclerosis identified by the presence of carotid plaque and increased intima-media thickness (IMT) in an older Chinese population.

METHODS

1996 subjects (992 (49.7%) men aged 50-85 years) from the Guangzhou Biobank Cohort Study-Cardiovascular Subcohort (GBCS-CVD) were genotyped. Carotid plaque and IMT were assessed by B-mode ultrasonography.

RESULTS

In male subjects, the C allele of TGFB1 rs4803455 was significantly associated with prevalence of carotid plaque (adjusted OR: 2.49, 95% CI: 1.16-5.36, P = 0.03). The C allele was related to increased number of common carotid artery (CCA) plaques (P=0.03) and larger carotid plaque area (P = 0.02) in men. The homozygous carriers of allele C in male subjects also had a higher risk of having carotid IMT ≥ 1 mm (adjusted OR: 1.75, 95% CI: 1.05-2.93, P = 0.03). These associations were independent of age, smoking, physical activity, body mass index, blood pressure, lipid profile, fasting glucose and high sensitivity C-reactive protein.

CONCLUSION

This is the first study to show that the C allele in TGFB1 was associated with increased risk of atherosclerosis in older Chinese men. Further investigations on the linkage between the TGFB1 gene and progression of atherosclerosis in asymptomatic populations are warranted.

Polymorphisms in promoter sequences of the p15 ( INK4B ) and PTEN genes of normal Japanese individuals

Gene promoter regions of p15(INK4B), a cyclin-dependent kinase inhibitor, and phosphatase and tensin homolog (PTEN), a dual-function protein and lipid phosphatase, interact with regulatory factors for gene transcription and methylation. Normal individuals exhibit sequence polymorphisms in these regulatory genes. We isolated genomic DNA from whole blood of healthy Japanese individuals and sequenced promoter regions of the p15 ( INK4B ) and PTEN genes. We also examined the influence of polymorphisms on promoter activity in several cell lines. We identified polymorphisms at positions -699, -394, and -242 and an insertion at position -320 in the p15 ( INK4B ) gene and a polymorphism at position -1142 in the PTEN gene. Reporter gene analysis revealed that these polymorphisms influenced transcriptional regulation in their cell lines. Our results indicate for the first time that promoter sequences of the p15 ( INK4B ) and PTEN genes differ among normal Japanese individuals and that promoter polymorphisms can influence gene transcription.

Polymorphisms in the genes encoding TGF-beta1, TNF-alpha, and IL-6 show association with type 1 diabetes mellitus in the Slovak population

Numerous cytokines have been shown to participate in the pathogenesis of type 1 diabetes (T1D). As gene polymorphisms can influence cytokine production or function, they may potentially contribute to genetic predisposition to the disease. The aim of this study was therefore to investigate the role of 22 single nucleotide polymorphisms (SNPs) in 13 cytokine and cytokine receptor genes in genetic susceptibility to T1D. Polymerase chain reaction with sequence-specific primers was used to genotype cytokine SNPs and HLA-DRB1 alleles in 151 diabetics and 140 healthy individuals of Slovak origin. Univariate analysis showed that transforming growth factor (TGF)-beta1 codon 10 TT homozygotes were significantly more susceptible to developing T1D than C allele carriers (P (c) = 0.0066, OR = 2.46). Furthermore, tumor necrosis factor (TNF)-alpha -308 A allele carriers were also significantly overrepresented among the diabetics (P (c) = 0.0031, OR = 2.62); however, the association of the -308 A allele with T1D might be due to its strong linkage disequilibrium with the susceptibility allele HLA-DRB1*0301. An association was also found with interleukin (IL)-6 -174 G/C and nt565 G/A SNPs; however, its significance was lost when statistical correction was applied. These data suggest that the TGF-beta1 codon 10 SNP is among numerous genetic variations with small individual effects on T1D development. Moreover, a possible role of TNF-alpha and IL-6 SNPs cannot be ruled out, although their association with T1D was due to strong LD with the HLA class II susceptibility allele or did not withstand statistical correction, respectively.