-509C>T polymorphism in the TGF-beta1 gene promoter, impact on the hepatocellular carcinoma risk in Chinese patients with chronic hepatitis B virus infection

Correlation of IL-10 and IL18 with the development of liver cirrhosis associated with hepatitis B virus infection: A systematic review

BACKGROUND

Patients who have been infected with the Hepatitis B virus (HBV) are susceptible to developing liver cirrhosis (LC) and hepatocellular carcinoma (HCC). The objective of this systematic review was to comprehensively scrutinize the existing evidence concerning the association between host genetic polymorphisms and HBV-associated LC.

METHODS

We searched databases of PubMed, Scopus, and Web of Science for relevant articles published from building databases to 25 October 2023.

RESULT

We detected 104 relevant articles, relating to 84 individuals genes. Nine genes had the strong evidence of correlation, including IL-10, IL-18, IL-1B, TGF- β, TLR3, STAT4, IL-1RN, Tim3, and IFN receptors. A positive correlation was found for 33 genes but this data had not yet been replicated, 11 genes had limited or mixed evidence of a correlation, and 34 genes indicated no correlation. IL-10 and IL-18 had the most evidence of correlation. There was a notable amount of diversity in both the design and method of studies and data quality.

CONCLUSION

IL-10 and IL-18 had the most evidence of correlation. There was a notable amount of diversity in both the design and method of studies and data quality. It is of necessary to take into account the fundamental mechanism behind these associations and discern those that are confounded by the coexistence of other LC/HCC risk factors and response to therapy. These results are expected to guide future studies on the genetic susceptibility of HBV-related LC/HCC.

Genotypic and allelic distribution of IFN-γ +874T/A and TGF-β1 -509C/T single-nucleotide polymorphisms in human immunodeficiency virus-infected Thais

Advances in antiretroviral therapy (ART) have led to a decrease of acquired immunodeficiency syndrome (AIDS)-related mortality, and an increase of non-AIDS illnesses in people living with HIV (PLWH). Risks for HIV-related chronic inflammation leading to non-AIDS illnesses in PLWH have been increasingly clarified including immunogenetic factors. This study aimed to examine distribution of genotypic and allelic frequencies of the well-characterized interferon-γ (IFN-γ) +874T/A and transforming growth factor-β1 (TGF-β1) -509C/T single nucleotide polymorphisms (SNPs) in Thai PLWH. The cross-sectional study was conducted in 191 Thai HIV patients. Most patients were under ART (74.3%) and maintained a relatively high median of CD4⁺  cell count (364.5 [5-1601] cells/μl). The frequencies of IFN-γ +874T/A  SNP genotypes were 9.0% AA, 38.3% AT, and 52.7% TT and those of the SNP alleles were 28.1% A and 71.9% T. The rates of TGF-β1-509C/T SNP genotypes were 15.7% CC, 44.0% CT, and 40.3% TT and those of the SNP alleles were 37.7% C and 62.3% T. The more frequent TT genotypes and T allele of the IFN-γ +874T/A SNP, and relatively more prevalent TT and CT genotypes and T allele of TGF-β1 -509C/T SNP were potentially associated with disease progression to non-AIDS complication in Thai PLWH and required further investigation. This study provides the immunogenetic data potentially supporting mechanisms for chronic immune activation in PLWH under long-term suppressive ART.

Association of Transforming Growth Factor β1 Gene Polymorphisms and Inflammatory Factor Levels with Susceptibility to Sepsis

Objective: To study the association of transforming growth factor β1 (TGF-β1) gene single nucleotide polymorphisms (SNPs) and plasma TGF-β1 levels with susceptibility to sepsis. Methods: The genotypes of the TGF-β1 gene rs1800469, rs1800468, rs1800470, and rs1800471 loci in 285 sepsis patients (119 patients with severe sepsis and 166 patients with mild sepsis) and 285 healthy individuals (control group) were analyzed through Sanger sequencing. Enzyme-linked immunosorbent assay was used to detect the levels of plasma inflammatory factors. Results: The TGF-β1 gene SNP rs1800469 C allele was 0.56 times lower than the T allele in terms of risk of susceptibility to sepsis (95% confidence interval [CI]: 0.43-0.72, p < 0.01). Carriers of the A allele at the rs1800468 locus of the TGF-β1 were 2.82 times more susceptible to sepsis than those with the G allele (95% CI: 1.62-4.91, p < 0.01). The T allele at the rs1800470 locus of TGF-β1 produced a lower risk of sepsis than those with the C allele (odds ratio [OR] = 0.74, 95% CI: 0.57-0.94, p = 0.02). The risk of susceptibility to sepsis in the TGF-β1 rs1800471 locus G allele was 3.54 times higher than that of C allele (95% CI: 2.14-5.86, p < 0.01). The TGF-β1 gene rs1800469 T > C and rs1800470 C > T were associated with mild sepsis, whereas rs1800468 G > A and rs1800471 C > G were associated with severe sepsis (p < 0.01). The TGF-β1 gene rs1800469 T > C and rs1800470 C > T were associated with lower plasma TGF-β1 levels, whereas rs1800468 G > A and rs1800471 C > G were associated with higher TGF-β1 levels (p < 0.05). Conclusion: The alleles T > C of rs1800469 and C > T of rs1800470 of the TGF-β1 gene were associated with lower plasma TGF-β1 levels and a reduced risk of sepsis susceptibility, whereas the alleles rs1800468 G > A and rs1800471 C > G were associated with higher TGF-β1 levels and risk of susceptibility to sepsis.

New Gene Variants Associated with the Risk of Chronic HBV Infection

Some patients with chronic hepatitis B virus (HBV) infection failed to clear HBV, even persistently continue to produce antibodies to HBV. Here we performed a two stage genome wide association study in a cohort of Chinese patients designed to discover single nucleotide variants that associate with HBV infection and clearance of HBV. The first stage involved genome wide exome sequencing of 101 cases (HBsAg plus anti-HBs positive) compared with 102 control patients (anti-HBs positive, HBsAg negative). Over 80% of individual sequences displayed 20 × sequence coverage. Adapters, uncertain bases > 10% or low-quality base calls (> 50%) were filtered and compared to the human reference genome hg19. In the second stage, 579 chronic HBV infected cases and 439 HBV clearance controls were sequenced with selected genes from the first stage. Although there were no significant associated gene variants in the first stage, two significant gene associations were discovered when the two stages were assessed in a combined analysis. One association showed rs506121-"T" allele [within the dedicator of cytokinesis 8 (DOCK8) gene] was higher in chronic HBV infection group than that in clearance group (P = 0.002, OR = 0.77, 95% CI [0.65, 0.91]). The second association involved rs2071676-A allele within the Carbonic anhydrase (CA9) gene that was significantly elevated in chronic HBV infection group compared to the clearance group (P = 0.0003, OR = 1.35, 95% CI [1.15, 1.58]). Upon replication these gene associations would suggest the influence of DOCK8 and CA9 as potential risk genetic factors in the persistence of HBV infection.

A comprehensive evaluation of single nucleotide polymorphisms associated with hepatocellular carcinoma risk in Asian populations: A systematic review and network meta-analysis

BACKGROUND

Single nucleotide polymorphisms (SNPs) have been inconsistently associated with hepatocellular carcinoma (HCC) risk. This meta-analysis aimed to synthesize relevant data on SNPs associated with HCC in the Asian population.

METHODS

Databases were searched to identify association studies of SNPs and HCC in Asians published through January 2019. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated based on 41 studies (13,167 patients with HCC and 15,886 noncancer controls). Network meta-analysis and Thakkinstian's algorithm were used to select the most appropriate genetic model, along with false positive report probability (FPRP) for noteworthy associations.

RESULTS

Eleven SNPs meeting the inclusion criteria were tested for association with HCC, including CCND1 rs9344, PTGS2 rs689466, IL18 rs187238 and rs1946518, KIF1B rs17401966, MDM2 rs2279744, MIR146A rs2910164, MIR149 rs2292832, MIR196A2 rs11614913, MIR499A rs3746444, and TGFB1 rs1800469. A significant increase for HCC risk was observed for MDM2 rs2279744, and the dominant (pooled OR = 1.59, 95% CI: 1.26-2.00) and codominant (pooled OR = 1.37, 95% CI: 1.18-1.60) models were determined to be the most appropriate models. MIR499A rs3746444 also showed a significant association with HCC risk under the allele contrast model (pooled OR = 1.36, 95% CI: 1.05-1.77). Only the significance of MDM2 rs2279744 was noteworthy (FPRP < 0.2).

CONCLUSIONS

MDM2 rs2279744 is associated with HCC susceptibility in Asians, and the dominant and codominant models are likely the most appropriate models to estimate HCC risk.

Association between host TNF-α, TGF-β1, p53 polymorphisms, HBV X gene mutation, HBV viral load and the progression of HBV-associated chronic liver disease in Indonesian patients

In developing countries, including Indonesia, there is a high mortality rate associated with the progression of hepatitis B virus (HBV)-associated chronic liver disease (CLD). The pathogenesis of HBV infection is influenced by viral and host factors. To determine potential associations between these factors, host single nucleotide polymorphisms (SNPs) on TNF-α, TGF-β1 and p53, HBV X gene mutation and HBV viral load were investigated in patients with HBV-associated CLD in Surabaya, Indonesia. Sera were collected from 87 CLD patients with HBV infection. TNF-α, TGF-β1 and p53 SNPs were genotyped by PCR restriction fragment length polymorphism. The HBV X gene was sequenced and compared with reference strains to determine mutations and the viral load was measured using reverse transcription-quantitative PCR. In Indonesian patients, no association between TNF-α, TGF-β1 and p53 SNPs and CLD or X gene mutation were identified. A total of 23% (20/87) of samples had HBV X gene mutations, including ten substitution types, one deletion and one insertion. Multinomial regression analysis revealed that the K130M/V131I mutations were correlated with CLD progression (OR, 7.629; 95% CI, 1.578-36.884). Significant differences in viral load were found in HBV-infected patients who had X gene mutations, such as R87W/G, I127L/T/N/S and K130M/V131I mutations (P<0.05). The presence of K130M and V131I mutations may be predictive for the progression of HBV-associated CLD in Indonesia.

TGF-β1 rs1800469 gene polymorphism in the development of cirrhosis & hepatocellular carcinoma in Pakistani HCV patients

Hepatocellular carcinoma (HCC) has been increasing among Pakistani males. Aim: The main objective of this study was to evaluate the role of TGF-β-1 gene polymorphism as a risk factor in chronic hepatitis C virus (HCV) infected HCC patients in Pakistan. Patients & methods: A total of 286 subjects were recruited into three different groups (Group I: 96 healthy controls, Group II: 96 HCV, Group III: 94 HCC). Results: A significant increase in genotype and allele frequencies of TGF-β-1 gene was observed in HCC, HCV with OR = 1.9; 95% CI: 1.275–2.871; p > 0.05, OR = 1.6; 95% CI: 1.12–2.51; p > 0.05 and OR = 1.7; 95% CI: 1.036–1.923; p > 0.05. Conclusion: A higher frequency of the TT genotype and T allele of the TGF-β-1 gene is observed in Pakistani HCV and HCC patients.

Transforming growth factor-β1 gene promoter -509C/T polymorphism in association with expression affects colorectal cancer development and depends on gender

It is widely known that sporadic colorectal cancer (CRC) is age-related diseases with higher incidence rate among men. Transforming growth factor-β1 (TGF-β1) is a major immune regulatory cytokine with a great impact and dual role in gastrointestinal carcinogenesis. In this context, the aim of the study was to explore the role of circulating TGF-β1 and the -509C/T functional promoter polymorphism (rs1800469) within the TGF-β1 gene (TGFB1) in the susceptibility, progression, and prognosis of CRC among Bulgarian male and female patients. Patients with sporadic CRC and healthy controls were genotyped by polymerase-chain reaction–restriction fragment length polymorphism. Serum TGF-β1 levels before and after curative surgery were determined by ELISA. Total RNA was extracted from paired tumor, normal mucosa and distant metastasis samples and was used for quantitative detection of TGFB1 mRNA by TaqMan qPCR.We observed that TGF-β1 serum levels depend on the -509C/T genotype in combination with gender. TGF-β1 serum levels in CRC patients were decreased compared to controls, but statistical significance was reached only for men. In the stratified analysis by gender and genotype, a significant association was found for the CC genotype. Overall, our results indicate that the -509C allele increased the cancer risk, particularly for advanced stages (OR = 1.477; p = 0.029). The results from the relative mRNA quantification showed a significant upregulation of TGFB1 in distant metastases compared to primary tumor tissues and higher TGFB1 mRNA levels in men (RQ = 4.959; p = 0.022). In conclusion, we present data that diminished circulating TGF-β1 due to the CC genotype could be a possible risk factor for tumor susceptibility and progression. This association is more pronounced in males than in females. Colorectal cancer tissue expression of TGFB1 gene mRNA correlates with tumor progression and metastasis.

Enhanced circulating transforming growth factor beta 1 is causally associated with an increased risk of hepatocellular carcinoma: a mendelian randomization meta-analysis

The aim of this study was to test the causal association between circulating transforming growth factor beta 1 (protein: TGF-β1 and coding gene: TGFB1) and hepatocellular carcinoma by choosing TGFB1 gene C-509T polymorphism as an instrument in a Mendelian randomization (MR) meta-analysis. Ten English articles were identified for analysis. Two authors independently assessed each article and abstracted relevant data. Odds ratio (OR) and weighted mean difference (WMD) with 95% confidence interval (CI) were synthesized under a random-effects model. Overall, the association of C-509T polymorphism with hepatocellular carcinoma was negative, but its association with circulating TGF-β1 was statistically significant, with a higher concentration observed in carriers of the -509TT genotype (WMD, 95% CI, P: 1.72, 0.67–2.78, 0.001) and -509TT/-509TC genotypes (WMD, 95% CI, P: 0.98, 0.43–1.53, < 0.001). In subgroup analysis, C-509T polymorphism was significantly associated with hepatocellular carcinoma in population-based studies under homozygous-genotype (OR, 95% CI, P: 1.74, 1.08–2.80, 0.023) and dominant (OR, 95% CI, P: 1.48, 1.01–2.17, 0.047) models. Further MR analysis indicated that per unit increase in circulating TGF-β1 was significantly associated with a 38% (95% CI: 1.03–4.65) and 49% (95% CI: 1.01–6.06) increased risk of hepatocellular carcinoma under homozygous-genotype and dominant models, respectively. Conclusively, based on a MR meta-analysis, our findings suggest that enhanced circulating TGF-β1 is causally associated with an increased risk of hepatocellular carcinoma.

Association between TGFβ1 polymorphisms and chronic hepatitis B infection in an Iranian population

INTRODUCTION:

Transforming growth factor-beta 1 (TGFβ1) is a potent suppressive cytokine that contributes to chronic hepatitis B (CHB) infection. Disparities in TGFβ1 production among individuals have been attributed to TGFβ1 genetic polymorphisms. We examined whether three putative polymorphisms in TGFβ1[-509 C/T (rs1800469), +869 C/T (rs1800470), and +11929 C/T (rs1800472)]are associated with CHB infection in a South-Eastern Iranian population.

METHODS:

In total, 341 subjects were recruited, including 178 patients with CHB and 163 healthy individuals as controls. Genotyping of the three TGFβ1 SNPs was performed by tetra amplification refractory mutation system-PCR.

RESULTS:

TheTGFβ1 +869 TT vs.CC genotype in codominant (OR=0.445, p=0.012) and TT vs. TC+CC in the recessive (OR=0.439, p=0.003) model as well as the variant allele T vs. C(OR=0.714, p=0.038) were associated with lower CHB infection risk. However, the +11929 C/T polymorphism was associated with increased CHB risk, and the CT vs. CC genotype (OR=2.77, P=0.001) and T variant allele (OR=2.53, P=0.002) were risk factors for CHB. Furthermore, TTT (+869/-509/+11929) and CCC haplotypes were risk and protective factors for CHB, respectively. We found no significant association between viral DNA load and TGFβ1 genotype or hepatic enzyme levels (p >0.05).

CONCLUSIONS:

Results indicated that the TGFβ1+869TT genotype and T allele were protective factors, whereas the +11929 CT genotype and T allele were risk factors for CHB infection.

The Synergistic Effect of TNFα -308 G/A and TGFβ1 -509 C/T Polymorphisms on Hepatic Fibrosis Progression in Hepatitis C Virus Genotype 4 Patients

Tumor necrosis factor-alpha (TNFα) and transforming growth factor-beta (TGFβ1) cytokines are highly implicated in liver fibrosis. Polymorphisms in these cytokines affect their expression, secretion, and activity. This study aimed to evaluate the influence of TNFα -308 G/A and TGFβ1 -509 C/T polymorphism on hepatic fibrosis progression in Egyptian patients with hepatitis C virus (HCV) genotype 4. Genotyping of TNFα -308 G/A and TGFβ1 -509 C/T was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis in 122 subjects (50 healthy controls and 72 HCV patients). Also, serum TNFα and TGFβ1 levels were detected by enzyme-linked immunosorbent assay (ELISA). The genotyping results of early (F0-F1, n = 36) and late (F2-F4, n = 36) HCV fibrosis patients showed that late fibrosis patients had higher TNFα -308 AA genotype and TGFβ1 -509 TT genotype than early fibrosis patients (p = 0.016, 0.028, respectively). Moreover, the TNFα and TGFβ1 serum levels were significantly higher in HCV patients with TNFα A containing genotypes (GA+AA) (p = 0.004) and patients with TGFβ1 T containing genotypes (CT+TT) (p = 0.001), respectively. The combined unfavorable TNFα (GA/AA) and TGFβ1 (CT/TT) genotypes were highly associated with abnormal liver function parameters and were significantly higher in high activity (A2-A3) and late fibrosis (F2-F4) HCV patients (p = 0.023, 0.029). The multivariate analysis results confirmed that the combined TNFα-308 (AA) and TGFβ1 -509 (TT) unfavorable genotypes increased the risk of hepatic fibrosis progression by 6.4-fold than combined favorable genotypes (odds ratio: 6.417, 95% confidence interval [1.490-27.641], p = 0.013). In conclusion, both TNFα -308 G/A and TGFβ1 -509 C/T polymorphisms synergistically influence the hepatic fibrosis progression and can be used as potential biomarkers to predict hepatic disease progression in chronic hepatitis C patients.

Association between TGF-β1 rs1800469 polymorphism and susceptibility to hepatocellular carcinoma in Chinese Guangxi populations: A meta-analysis

AIM

To systematically evaluate the association between the transforming growth factor-β1 (TGF-β1) rs1800469 (C-509T) polymorphism and susceptibility to hepatocellular carcinoma in Chinese Guangxi populations.

METHODS

An electronic search of PubMed, EMBASE, CNKI, Weipu, and Wanfang database for relevant articles was conducted. The difference of TGF-β1 rs1800469 (C-509T) genotypes (T vs C, TT vs CC, TC vs CC, TT+TC vs CC, and TT vs TC+CC) between cases and controls was analyzed through meta-analysis.

RESULTS

A total of six studies involving 2202 cases and 2382 controls were finally included. There was evidence of association between TGF-β1 rs1800469 (C-509T) polymorphism and the risk of hepatocellular carcinoma in Guangxi populations (TC vs CC: OR = 1.18; 95%CI: 1.03-1.36, P = 0.02).

CONCLUSION

Our meta-analysis suggested that the TGF-β1 rs1800469 (C-509T) polymorphism is more likely to be associated with hepatocellular carcinoma risk in Guangxi populations, and TGF-β1 rs1800469 (C-509T) TC genotype increases the susceptibility to hepatocellular carcinoma in Guangxi populations.

Hepatitis-related hepatocellular carcinoma: Insights into cytokine gene polymorphisms

Hepatocellular carcinoma (HCC) is a primary liver cancer, which is one of the most prevalent cancers among humans. Many factors are involved in the liver carcinogenesis as lifestyle and environmental factors. Hepatitis virus infections are now recognized as the chief etiology of HCC; however, the precise mechanism is still enigmatic till now. The inflammation triggered by the cytokine-mediated immune response, was reported to be the closest factor of HCC development. Cytokines are immunoregulatory proteins produced by immune cells, functioning as orchestrators of the immune response. Genes of cytokines and their receptors are known to be polymorphic, which give rise to variations in their genes. These variations have a great impact on the expression levels of the secreted cytokines. Therefore, cytokine gene polymorphisms are involved in the molecular mechanisms of several diseases. This piece of work aims to shed much light on the role of cytokine gene polymorphisms as genetic host factor in hepatitis related HCC.

Hepatocarcinogenesis associated with hepatitis B, delta and C viruses

Globally, over half a billion people are persistently infected with hepatitis B (HBV) and/or hepatitis C viruses. Chronic HBV and HCV infection frequently lead to fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Co-infections with hepatitis delta virus (HDV), a subviral satellite requiring HBV for its propagation, accelerates the progression of liver disease toward HCC. The mechanisms by which these viruses cause malignant transformation, culminating in HCC, remain incompletely understood, partially due to the lack of adequate experimental models for dissecting these complex disease processes in vivo.

Host nucleotide polymorphism in hepatitis B virus-associated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is etiologically linked with hepatitis B virus (HBV) and is the leading cause of death amongst 80% of HBV patients. Among HBV affected patients, genetic factors are also involved in modifying the risk factors of HCC. However, the genetic factors that regulate progression to HCC still remain to be determined. In this review, we discuss several single nucleotide polymorphisms (SNPs) which were reportedly associated with increased or reduced risk of HCC occurrence in patients with chronic HBV infection such as cyclooxygenase (COX)-2 expression specifically at COX-2 -1195G/A in Chinese, Turkish and Egyptian populations, tumor necrosis factor α and the three most commonly studied SNPs: PAT-/+, Lys939Gln (A33512C, rs2228001) and Ala499Val (C21151T, rs2228000). In genome-wide association studies, strong associations have also been found at loci 1p36.22, 11q22.3, 6p21 (rs1419881, rs3997872, rs7453920 and rs7768538), 8p12 (rs2275959 and rs37821974) and 22q11.21. The genes implicated in these studies include HLA-DQB2, HLA-DQA1, TCF19, HLA-C, UBE2L3, LTL, FDX1, MICA, UBE4B and PG. The SNPs found to be associated with the above-mentioned genes still require validation in association studies in order to be considered good prognostic candidates for HCC. Screening of these polymorphisms is very beneficial in clinical experiments to stratify the higher or lower risk for HCC and may help in designing effective and efficient HCC surveillance programs for chronic HBV-infected patients if further genetic vulnerabilities are detected.

Anti-HBV Drugs: Progress, Unmet Needs, and New Hope

Approximately 240 million people worldwide are chronically infected with hepatitis B virus (HBV), which represents a significant challenge to public health. The current goal in treating chronic HBV infection is to block progression of HBV-related liver injury and inflammation to end-stage liver diseases, including cirrhosis and hepatocellular carcinoma, because we are unable to eliminate chronic HBV infection. Available therapies for chronic HBV infection mainly include nucleos/tide analogues (NAs), non-NAs, and immunomodulatory agents. However, none of them is able to clear chronic HBV infection. Thus, a new generation of anti-HBV drugs is urgently needed. Progress has been made in the development and testing of new therapeutics against chronic HBV infection. This review aims to summarize the state of the art in new HBV drug research and development and to forecast research and development trends and directions in the near future.

Th1/Th2 cytokines and their genotypes as predictors of hepatitis B virus related hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the predominant type of primary liver cancer, is one of the most serious life-threatening malignancies, worldwide. In majority of the cases, HCC develops after prolonged and persistent chronic liver disease. hepatitis B virus (HBV) or HCV infection is prominent etiological factors, attributing to this condition. It has been well documented that HBV, being the inducer of chronic inflammation, is the main causative agent in causing HCC, particularly in Asian countries. The HBV infection leads to a wide range of clinical symptoms from carrier state to malignancy. Cytokines being immune-modulatory molecules, are the key mediators in the defense mechanism against viral infection. In this regard, this review will detail the substantial role of key Th1: interleukin 1 (IL-1), IL-2, IL-12, tumor necrosis factor-α, interferon-γ; Th2: IL-4, IL-10 and non Th1/Th2: IL-6, transforming growth factor-β1 cytokines genotypes in analyzing the variability in the clinical manifestations in an HBV-afflicted individual, which might finally, culminates into HCC. Since cytokine production is regulated genetically, the cytokine promoter region single-nucleotide polymorphisms induced changes, greatly affects the cytokine production, thus resulting into differential outcome of immune balance.

TGFβ-1 and TGFBR2 polymorphisms, cooking oil fume exposure and risk of lung adenocarcinoma in Chinese nonsmoking females: a case control study

Background

Transforming growth factor-β (TGF-β) plays an important role in regulating cellular functions, and many studies have demonstrated important roles for TGF-β in various cancers. Single nucleotide polymorphisms (SNPs) of TGF-β may influence lung carcinogenesis. The aim of this study was to test whether TGF-β1 C509T and TGF-β receptor II (TGFBR2) G-875A polymorphisms were associated with lung adenocarcinoma in nonsmoking females.

Methods

A hospital-based case–control study was performed in Chinese nonsmoking females. Genotyping was performed using TaqMan SNP genotyping assay, and demographic data and environmental exposure were collected by trained interviewers after informed consents were obtained.

Results

A total of 272 (95.4%) cases and 313 (99.4%) controls were successfully genotyped, and the results showed that the polymorphic allele frequencies of C509T and G875A were similar among lung adenocarcinoma patients and controls (P=0.589 and 0.643, respectively). However, when the data were stratified for cooking oil fume exposure, the TT genotype of the TGFB1 C509T polymorphism showed a significantly decreased risk for lung adenocarcinoma compared with the CC genotype (adjusted OR=0.362, 95% CI=0.149–0.878, P=0.025).

Conclusions

TGF-β1 gene C509T polymorphism might be associated with decreased risk of lung adenocarcinoma in Chinese females exposed to cooking oil fumes, but no association was observed TGFBR2 gene G875A polymorphism.

Immunomodulatory effects of transforming growth factor-β in the liver

Members of the transforming growth factor-β (TGF-β) family are potent regulatory cytokines that affect multiple cell types of the immune system mediating pro-inflammatory or anti-inflammatory responses. In the liver, TGF-β is produced by a multitude of non-parenchymal liver cells including hepatic stellate cells (HSCs), liver sinusoidal endothelial cells (LSECs), Kupffer cells (KCs), and dendritic cells (DCs) as well as natural killer (NK) T cells among other hepatic lymphocytes. The effect of TGF-β on other cells is highly versatile. In concert with other soluble factors, it controls the maturation, differentiation and activity of various T cell subsets that either prevent or actuate infections, graft-versus-host reactions, immune diseases, and cancer formation. During the last decades, it became evident that some TGFB1 polymorphisms are associated with the pathogenesis of hepatic disease and that plasma TGF-β is a suitable biomarker to detect liver lesions. Moreover, since TGF-β has capacity to influence the quantity and quality of T cell subsets as well as their activity, it is obvious that a well-balanced TGF-β activity is essential for liver homeostasis. In the present review, we highlight some pivotal functions of TGF-β in hepatic immunobiology. We discuss its regulatory function on adaptive immunity, the impact on differentiation of various T cell subsets, its crosstalk with Toll like receptor signaling, and its contribution to functional impairment of the liver.

TGF-β1 genotype in pediatric migraine patients

There is no information about the role of transforming growth factor-beta 1 (TGF-β1) in the pathogenesis of pediatric migraine. This study included 100 consecutive children and adolescents in whom migraine was diagnosed and 88 healthy children and adolescents. The isolated genomic DNA was used as a template for TGFβ-1 (-800G/A, -509C/T, 869T/C [codon 10] and 915G/C [codon 25]) genotyping. The allelic frequency of 509C/T was significantly different between control and migraine without aura patients (P = .04). Codon 10 C/T genotypic and C10 C allelic frequency of TGF-β1 polymorphisms were significantly higher in migraine and migraine without aura patients versus healthy controls (P = .00; P = .00). To our knowledge, this is the first report dealing with the relationship between TGF-β1 genotype and migraine in the pediatric age group. Further studies related to this subject are needed, along with a search for new therapeutic agents with anti-inflammatory properties.

Effect of IL-12B, IL-2, TGF-β1, and IL-4 polymorphism and expression on hepatitis B progression

The hepatitis B virus (HBV) infection-induced chronic inflammation is considered to be the major etiological factor for HBV-related disease chronicity. Cytokines act as the key coordinators of the inflammatory responses involved in HBV disease pathogenesis. The present study assessed association among IL-12B(+1188), IL-2(-330), TGF-β1(-509), and IL-4(-590) genotypes; mRNA; and protein levels with HBV-hepatocellular carcinoma (HCC) risk in India. For this, 403 subjects (153 controls, 67 inactive HBV-carriers, 62 chronic-active HBV patients, 62 HBV-cirrhotics, and 59 HBV-HCC ssubjects) were enrolled in the study. The genotyping was carried by polymerase chain reaction (PCR)-restriction fragment length polymorphism (IL-12+1188A/C, IL-2-330T/G, and TGF-β1-509C/T), and allele specific (AS)-polymerase chain reaction (IL-4-590C/T). Enzyme-linked immunosorbent assay and reverse transcriptase-polymerase chain reaction methods were used for assessing protein and the mRNA expression, respectively, of the mentioned cytokines. The study revealed that the IL-12B(+1188) CC genotype shared a significant positive association with hepatitis, among controls. While, in the case of IL-2(-330), both the TG and GG genotypes were not significantly associated with HCC risk. The TGF-β1(-509) TT genotype acted as a potential protective factor for cirrhosis and the HCC risk, among carriers. On the contrary, the IL-4(-590) CT genotype was found to be a vital protective factor for the development of hepatitis, among carriers. Besides, IL-12B, TGF-β1, and IL-2 seem to be majorly involved in the development of HCC, while, IL-4 might be responsible for the progression of the HBV disease till cirrhosis development. These initial findings are indicative of the vital role of genotypes and/or levels of IL-12B, IL-2, IL-4, and TGF-β1 in HBV disease chronicity in Indian population.

Important roles played by TGF-β in hepatitis B infection

Hepatitis B virus (HBV) which includes, fulminant, acute, chronic, asymptomatic, and occult HBV infection is the most prevalent virus that leads to human liver diseases. Chronic, asymptomatic, and occult infection can induce further sever diseases such as hepatocellular carcinoma (HCC) and cirrhosis of the liver. The underlying mechanisms that allow progression of the prolonged forms of the infection and subsequent HCC or cirrhosis of the liver are yet to be clarified. However, many researchers have suggested that immunological and genetic parameters may play important roles in the etiology of hepatitis B. Transforming growth factor beta (TGF-β) is an important cytokine with dual regulatory functions in the immune system and in the responses against viral infections. However, the pathways and mechanisms controlling these are not fully understood. The crucial roles of TGF-β in the development of Th17 and T regulatory lymphocytes, the main cell types involved in autoimmunity and destructive immune related diseases, have been documented and this provides insights into TGF-β function during hepatitis infection and subsequent HCC and cirrhosis of the liver. Recent findings also confirm that TGF-β directly alters hepatocyte function during hepatitis B, hence, the aim of this review is to address the current data regarding the association and status of TGF-β with hepatitis B infection and its related disorders including HCC and cirrhosis of the liver.

Transforming growth factor beta-1 C-509T polymorphism and cancer risk: a meta-analysis of 55 case-control studies

AIM

To investigate the association of transforming growth factor-beta 1 (TGF-β1) C-509T polymorphism and susceptibility to cancer by means of meta-analysis.

METHODS

An extensive search was performed to identify eligible case-control studies investigating such a link. The strength of the association between TGF-β1 C-509T polymorphism and cancer risk was assessed by pooled odds ratios (ORs) and 95%confidence intervals (95%CIs) in fixed or random effects models.

RESULTS

55 published case-control studies with a total number of 21,639 cases and 28,460 controls were included. Overall, there was no association between TGF-β1 C-509T and cancer risk in all genetic comparison models (TT vs. CC: OR=1.01, 95%CI=0.89-1.15; T vs. C: OR=1.01, 95%CI=0.94-1.07). However, a stratified analysis by cancer type indicated -509 T allele was significantly associated with decreased risk of colorectal cancer (CRC) (TT vs. CT/CC: OR=0.85, 95%CI=0.76-0.95), especially for Caucasians (TT vs. CT/CC: OR=0.83, 95%CI=0.71-0.98) and for population-based studies (TT vs. CT/CC: OR=0.78, 95%CI=0.68- 0.89).

CONCLUSION

This meta-analysis suggested that TGF-β1 C-509T polymorphism might contribute to a decreased risk on colorectal cancer susceptibility, especially for Caucasians.

TGF-β1 -509C/T (or +869T/C) polymorphism might be not associated with hepatocellular carcinoma risk

Many studies have reported the role of transforming growth factor-β1 (TGF-β1) -509C/T or +869T/C polymorphism with hepatocellular carcinoma (HCC) risk. However, these studies have yielded conflicting results. Hence, we performed this meta-analysis to investigate the association between TGF-β1 -509C/T or +869T/C polymorphism and HCC. A total of 11 studies including 2,577 HCC cases and 4,107 controls were included in the meta-analysis. Overall, TGF-β1 -509C/T (or +869T/C) polymorphism was not associated with HCC risk (homogeneous co-dominant model: OR = 1.29, 95 % CI = 0.88-1.89; heterogeneous co-dominant model: OR = 1.15, 95 % CI = 0.91-1.45; dominant model: OR = 1.14, 95 % CI = 0.87-1.48; recessive model: OR = 1.15, 95 % CI = 0.89-1.49). In the subgroup analysis, TGF-β1 -509C/T (or +869T/C) polymorphism was significantly associated with HCC risk in Caucasians under the recessive model (OR = 1.65, 95 % CI = 1.07-2.55) but not in other genetic models. In addition, we did not observe significant association in Asians under all genetic models. In conclusion, our meta-analysis indicates that TGF-β1 -509C/T (or +869T/C) polymorphism was not associated with risk of HCC, although a marginal association was found for Caucasians. However, a study with the larger sample size is needed to further evaluate gene-environment interaction on the association.

Pathogenic mechanisms in HBV- and HCV-associated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a highly lethal cancer, with increasing worldwide incidence, that is mainly associated with chronic hepatitis B virus (HBV) and/or hepatitis C virus (HCV) infections. There are few effective treatments partly because the cell- and molecular-based mechanisms that contribute to the pathogenesis of this tumour type are poorly understood. This Review outlines pathogenic mechanisms that seem to be common to both viruses and which suggest innovative approaches to the prevention and treatment of HCC.

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.

An updated meta-analysis on the association of TGF-β1 gene promoter -509C/T polymorphism with colorectal cancer risk

AIM

Published data on the association between transforming growth factor-β1 (TGF-β1) gene promoter-509C/T polymorphism and colorectal cancer (CRC) risk are inconsistent and inconclusive. To derive a more precise estimation of this association, a meta-analysis was carried out.

METHODS

Meta-analysis was performed to evaluate reported studies of the relationship between TGF-β1 gene promoter-509C/T polymorphism and colorectal cancer risk using fixed-effects model and random-effects model.

RESULTS

We observed an increased colorectal cancer risk among subjects carrying TGF-β1 gene promoter-509CC+CT genotype (odds ratio (OR)=1.18%, 95% confidence interval (95% CI): 1.06-1.32) using 4440/6785 cases/controls in total population. We observed an increased risk of the TGF-β1 gene promoter -509CC, CT and CC+CT polymorphisms for colorectal cancer in population-based study (OR=1.36, 95% CI: 1.19-1.56, OR=1.18, 95% CI: 1.03-1.34 and OR=1.26, 95% CI: 1.12-1.43, respectively) in stratified analysis. We observed an increased colorectal risk among CC and CC+CT carriers in European and American population (OR=1.22, 95% CI: 1.04-1.43 and OR=1.18, 95% CI: 1.02-1.38, respectively). We also observed an increased risk of colon cancer among subjects carrying CC+CT genotype (OR=1.31, 95% CI: 1.05-1.63).

CONCLUSIONS

The present meta-analysis results suggest that TGF-β1 gene promoter -509C allele variant is a possible risk factor for developing colorectal cancer. Recommendations for further studies include pooling of individual data to verify results from the study and to facilitate evaluation of multigenic effects and detailed analysis of effect modification by environmental and lifestyle factors.

Correlation between TGF-β1-509 C>T polymorphism and risk of digestive tract cancer in a meta-analysis for 21,196 participants

The association between transforming growth factor β1 (TGF-β1)-509 C>T and risk of digestive tract cancer (DTC) remained uncertain as previous studies reported conflicting results. The aim of this study was to assess the association by using a meta-analysis. The databases of MEDLINE, EMBASE and WANGFANG (Chinese database) were retrieved, and latest update was on 2nd February, 2012. Pooled odds ratio and 95% confidence interval (OR and 95% CI) were calculated by using a fixed- or random-effect model. Ultimately, twenty nine case-control studies with 8664 cases and 12,532 controls were included in this meta-analysis. Overall, there was no association between TGF-β1-509 C>T and risk of DTC in all genetic comparison models (OR and 95% CI: 0.96 and 0.81-1.15 for TT vs. CC, 0.98 and 0.91-1.05 for T carriers vs. C carriers). When subgroup analyses were conducted according to ethnicity, types of cancer and sample size, T allele was significantly associated with decreased risk of DTC for Caucasians and for large sample-sized studies, and was associated with decreased risk of colorectal cancer (OR and 95% CI for TT vs. CC: 0.82 and 0.70-0.97 for Caucasians, 0.80 and 0.68-0.98 for large sample-sized studies, 0.78 and 0.62-0.97 for colorectal cancer). This study indicated that TGF-β1-509 C>T polymorphism was probably associated with risk of DTC, especially for Caucasians. Because of modest limitation, our findings should be confirmed by future studies.

Influence of transforming growth factor-β1 and tumor necrosis factor-α genes polymorphisms on the development of cirrhosis and hepatocellular carcinoma in chronic hepatitis C patients

BACKGROUND

Host genetic factors may affect clinical outcomes of hepatitis C virus (HCV) infection; however, the possible mechanisms remain largely unknown. This study aimed to evaluate transforming growth factor-β1 (TGF-β1)-509 and tumor necrosis factor-α (TNF-α)-308 genes polymorphisms as a risk factors for cirrhosis and hepatocellular carcinoma (HCC) in chronic hepatitis C patients.

MATERIALS AND METHODS

Two hundred and eighty HCV patients (152 patients with cirrhosis, 128 patients with HCC) and 160 controls were enrolled in the study. Polymorphisms of TGF-β1-509 and TNF-α-308 gene were determined using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). Serum TGF-β1 and TNF-α were determined using ELISA.

RESULTS

TGF-β1-509 TT, TNF-α-308 AA and GA genotypes frequencies were significantly increased in cirrhotic and HCC groups. Serum TGF-β1 and TNF-α level were significantly increased in TGF-β1-509 TT and TNF-α-308 AA genotypes respectively.

CONCLUSION

TGF-β1-509 and TNF-α-308 genes polymorphisms are associated with risk of liver cirrhosis and HCC in patients with chronic HCV infection.

MAGE-4 gene m-RNA and TGF in blood as potential biochemical markers for HCC in HCV-infected patients

Progression from chronic hepatitis C virus infection to cirrhosis then to hepatocellular carcinoma usually results in some protein changes in peripheral blood. We evaluated MAGE-4 mRNA, TGFβ1 and AFP in peripheral blood as potential biochemical markers for diagnosis and prognosis of some complications of HCV infection. MAGE-4 mRNA in blood by reverse transcription polymerase chain reaction, serum TGF-Β1 and AFP by ELISA was assayed in seventy-five individuals who were classified into five groups: group I (control) comprised fifteen apparently healthy volunteers, group II involved fifteen HCV-infected patients without cirrhosis, group III involved fifteen HCV fifteen HCV-infected patients with cirrhosis, group IV included fifteen HCV-infected patients with cirrhosis and early stage HCC, and group V included fifteen HCV cirrhotic patients and late-stage HCC. We found that the frequency of positivity of MAGE-4 among the late hepatoma group was 40 %, while in the early hepatoma group the positivity was 6.7 %. The results for TGF-Β1 revealed a significant increase in serum TGF-Β1 in groups IV and V as compared to control, II, III groups. The obtained results of AFP showed a significant positive increase in serum AFP in groups IV and V when compared to groups II and III. Detection of MAGE-4 transcripts in blood, especially with follow-up survey, may help to predict the prognosis and monitoring of the response to the therapy, and serum TGF-Β1 level in HCC patients is directly correlated with metastasis and recurrence of tumors and increases gradually with the progression of HCC.

Association between transforming growth factor-β1 polymorphisms and hepatocellular cancer risk: A meta-analysis

AIM

  The association between transforming growth factor-β1 (TGF-β1) gene polymorphisms and hepatocellular cancer (HCC) risk has been widely reported, but results were somewhat controversial. To derive a more precise estimation of the relationship between TGF-β1 polymorphisms and HCC risk, we conducted a meta-analysis of all available studies relating the C-509T and/or T869C polymorphisms of the TGF-β1 gene to the risk of developing HCC.

METHODS

  Two investigators independently searched the MEDLINE, PubMed, Web of Science, Embase, CNKI (China National Knowledge Infrastructure) and CBM (Chinese Biomedical Literature database) for the period up to August 2011.

RESULT

  A total of nine case-control articles were identified. Five studies with 1825 cases and 2869 controls for C-509T polymorphism, and six studies with 536 cases and 1496 controls for T869C polymorphism were included. In the overall analysis, no significant association between the polymorphisms and risk of HCC was observed. Stratified analysis showed that significant association between C-509T polymorphism and HCC was present only in controls with liver disease (T vs. C: odds ratio [OR] = 0.769, 95% confidence interval [CI] = 0.661-0.895; TT vs. CC: OR = 0.570, 95% CI = 0.412-0.788; TT/TC vs. CC: OR = 0.668, 95% CI = 0.523-0.854; TT vs.

TC/CC

OR = 0.717, 95% CI = 0.550-0.934), but not in healthy controls. With respect to T869C polymorphism, only a decreased risk was found in recessive models in controls with liver disease.

CONCLUSIONS

  This meta-analysis supports that the TGF-β1 C-509T polymorphism may act in a protecting role in HCC susceptibility in populations with related liver disease.

TNF-α -863 polymorphisms and the risk of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common type of highly malignant tumor. Guangxi is an area of China characterized by a high incidence of HCC. Previous epidemiological studies have found that chronic infection with hepatitis B virus (HBV) is one of the major etiological risk factors for HCC in China. With the increased understanding of the host immune response against HBV and the pathogenesis of the virus, at present, greater attention is being given to the immune response of cytokine genes, as polymorphisms may have a major impact on the course and outcome of HBV infection. In the present study, we genotyped tumor necrosis factor-α (TNF-α) rs1800629 (-308G/A), rs1800630 (-863C/A); interleukin-1B rs1143627 (-31T/C); and transforming growth factor β1 (TGF-β1) rs1800469 (-509C/T) in a hospital-based study of 772 HCC cases and 852 cancer-free controls. The distribution of the frequency of TNF-α rs1800630 sites of CC, CA, AA were 65.67, 27.46 and 6.87% in the case group, respectively, as compared with 67.02, 29.58 and 3.40% in the controls, all with a statistical significance (P<0.05). The logistic regression analysis revealed that the variant rs1800630 AA genotypes were associated with a significantly increasing risk of HCC (OR=2.058, 95% CI 1.289-3.287), compared with the wild-type rs1800630 CC. Further stratified analyses showed that after stratification for history of alcohol drinking, in a subgroup of individuals without a history of drinking, the HCC risk in the group with the TNF-α rs1800630 A allele was 1.839 times higher than that in the group with TNF-α rs1800630 C (P<0.010). These findings suggest that TNF-α rs1800630 may contribute to the risk of HCC, however, these data require further validation.

Relationship between a TGF-β1 gene polymorphism and HBV infection and familial clustering of hepatocellular carcinoma

AIM: To investigate the relationship between a single nucleotide polymorphism (SNP) of the TGF-β1 gene (rs1800469) and HBV infection and familial clustering of hepatocellular carcinoma in Guangxi, China.

METHODS: Blood samples collected from 114 family members (FHCC) whose families have had two or even more hepatocellular carcinoma patients and 114 healthy controls (FNC) who come from the families without any cancer. SNP genotyping was performed in these subjects using DNA sequencing and polymerase chain reaction-restriction fragment length polymorphism.

RESULTS: There were no statistical differences between the FHCC group and FNC group in the frequencies of the alleles (T, C) and genotypes (CC, TC, TT) at the rs1800469 locus, and in the distribution of the alleles (T, C) and frequencies of genotypes (TC, TT) between subjects who were infected by chronic hepatitis B (HBsAg positive) and those who were not infected (HBsAg negative) (all P > 0.05). However, there was a statistical difference in the frequency of genotype CC between the HBsAg-positive and -negative groups (P < 0.05).

CONCLUSION: The alleles (T, C) and genotypes (CC, TC, TT) at the rs1800469 locus in the TGF-β1 gene are not associated with familial clustering of hepatocellular carcinoma in families in Guangxi Province. The genotype CC at the rs1800469 locus might increase the risk for HBV infection.

Polymorphisms in the potential functional regions of the TGF-β 1 and TGF-β receptor genes and disease susceptibility in HBV-related hepatocellular carcinoma patients

Hepatocellular carcinoma (HCC) is a disease of multiple etiologies caused by the accumulation of genetic and epigenetic defects. Current evidence indicates that the transforming growth factor beta (TGF-β) signaling pathway has a significant impact on different cellular process. Members of the TGF-β superfamily (TGF-β1, the type I TGF-β receptor [TβRI], type II TGF-β receptor [TβRII], and type III TGF-β receptor]) play an important role in tumorigenesis. Numerous studies show that genetic polymorphisms in TGF-β superfamily genes are associated with HCC in East Asian populations. We studied 16 single nucleotide polymorphisms (SNPs) in four genes (TGF-β1, TβRI, TβRII, and TβRIII) to examine their associations with hepatocarcinogenesis. A total of 1228 Chinese Han participants were enrolled in the study (881 control participants who were negative for all hepatitis B virus [HBV] serum markers and 347 case participants with HBV-related HCC). Genotyping was conducted using the TaqMan method. The results showed that the frequency of the rs1805110 T allele was significantly higher in the case group than in the control group (P = 0.034). After stratification, the results for rs1805110 remained significant in male participants (P = 0.005), but there was no statistical difference in females. In males, the frequency of the C-C-G-C-A haplotype resulting from SNPs rs1805110, rs2810904, rs1805112, rs284878, and rs1804506 in TβRIII was significantly lower in the case group than in the control group (P = 0.001), whereas the reverse was true for the T-C-G-C-A haplotype (P = 0.036). We conclude that the rs1805110T allele is associated with susceptibility to HBV-related HCC in males.

An insertion/deletion polymorphism in the 3' untranslated region of type I collagen a2 (COL1A2) is associated with susceptibility for hepatocellular carcinoma in a Chinese population

Hepatocellular carcinoma (HCC) is one of the most common and severe diseases in the world. Besides the influence of environmental factors, such as viral infection, an increasing number of novel genetic components identified by genome-wide association studies have been associated with predisposition to HCC. Thus, studies focusing on functional variants in these findings are indispensable. In the present study, based on in-silico analysis, we carried out a case-control study in a Chinese population (207 cases and 245 controls) to investigate the association between HCC susceptibility with a 7 base pair (bp) insertion/deletion polymorphism (rs3917) in the 3'UTR of COL1A2. Our results showed that the ins/del + del/del genotype had an odds ratio of 1.76 (95% C.I.=1.03-3.01; P=0.028) for developing HCC compared to the ins/ins genotype. Carriers for the "del" allele of rs3917 were associated with a 1.73-fold increased risk for HCC (95% C.I.=1.06-2.84; P(trend)=0.02). Computational modeling suggests that this polymorphism is located in the hsa-let-7 g potential target sequence in the COL1A2 3' untranslated region. Our data suggest that most likely, common genetic changes in COL1A2 may influence HCC risk, at least in part by let-7 g-mediated regulation, which is possibly involved in the pathogenesis of HCC. The replication of our studies in other populations will further strengthen our understanding of this association.

Association between the TGFB1 -509C/T and TGFBR2 -875A/G polymorphisms and gastric cancer: a case-control study

The transforming growth factor-β (TGFβ) pathway plays an important role in various types of human cancer. However, the role of TGFB1 -509C/T and TGFBR2 -875A/G polymorphisms in gastric cancer is controversial. We aimed to investigate the associations between these polymorphisms and gastric cancer susceptibility, clinicopathological parameters and survival. A case-control study was conducted in 1,010 gastric cancer patients and 1,500 healthy controls. Genotypes were determined by PCR-restriction fragment length polymorphism and DNA sequencing. Compared with the TT genotype, the TGFB1 -509 C allele (CT/CC) was significantly associated with a reduced risk of gastric cancer (OR, 0.71; 95% CI, 0.58-0.87; p=0.001) and certain subtypes of gastric cancer including intestinal type (OR, 0.70; 95% CI, 0.57-0.87; p=0.001), poorly differentiated (OR, 0.67; 95% CI, 0.54-0.85; p=0.001) and stage TNM III+IV (OR, 0.73; 95% CI, 0.58-0.92; p=0.008). Compared with the TGFBR2 -875 GG genotype, carriers of the A allele (AA/AG) had a significantly decreased gastric cancer risk (OR, 0.58; 95% CI, 0.62-0.91; P<0.001). A combination of the TGFB1 -509 C and TGFBR2 -875 A alleles was associated with a further decreased risk of gastric cancer (OR, 0.42; 95% CI, 0.32-0.57, p<0.001). No significant correlation was observed between polymorphisms and survival of gastric cancer patients. Our results suggest that both the TGFB1 -509 and TGFBR2 -875 polymorphisms contribute to a decreased gastric cancer risk. The TGFB1 -509 polymorphism affects certain subtypes of gastric cancer according to clinicopathological parameters. A combination of the TGFB1 -509 C and TGFBR2 -875 A alleles conferred a further decreased gastric cancer risk. These findings provide clues to the biological mechanisms that underline tumor heterogeneity.

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.

Genetic variations and haplotypes in TIM-3 gene and the risk of gastric cancer

PURPOSE

T cell immunoglobulin and mucin domain-containing molecule 3 (TIM-3) could weaken the Th1-mediated anti-tumor responses and accelerate the tumor cell proliferation by inhabiting the production of IL-2 or IFN-γ. This study was to assess the association between TIM-3 genetic variations and the development of gastric cancer.

PATIENTS AND METHODS

Five polymorphisms located in the promoter or encoding region of TIM-3 gene were genotyped in 212 gastric cancer patients and 252 controls who matched with the patients on the frequency of age, gender, smoking, and drinking. Logistic regression was used to determine whether the inherited variations within TIM-3 gene were associated with gastric cancer risk. Linkage disequilibrium and Haplotype analyses were performed by using SHEsis program.

RESULTS

By the individual genotype analysis, three polymorphisms (-574G/T, -882C/T, and -1516G/T) within TIM-3 gene were significantly associated with gastric cancer in the study population [ORs (95% CIs): 2.74 (1.21-6.20), 3.19 (1.29-7.91), and 2.03 (1.15-3.59); respectively]. Among the gastric cancer patients, the relationship between the -1516 polymorphic genotype and the distant metastasis of tumor was found (OR = 2.21, 95% CI = 1.05-4.63). Under the analysis of haplotypes, an even stronger association with haplotype TTGCT was observed in gastric cancer risk (OR = 5.57, 95% CI: 1.04-29.80, P = 0.024).

CONCLUSION

These results indicated that the three genetic variations within the TIM-3 gene promoter may be associated with the increased susceptibility to gastric cancer, especially among the haplotypes with the risk.

Genetic variations at loci involved in the immune response are risk factors for hepatocellular carcinoma

Primary liver cancer is the third most common cause of cancer-related death worldwide, with a rising incidence in Western countries. Little is known about the genetic etiology of this disease. To identify genetic factors associated with hepatocellular carcinoma (HCC) and liver cirrhosis (LC), we conducted a comprehensive, genome-wide variation analysis in a population of unrelated Asian individuals. Copy number variation (CNV) and single nucleotide polymorphisms (SNPs) were assayed in peripheral blood with the high-density Affymetrix SNP6.0 microarray platform. We used a two-stage discovery and replication design to control for overfitting and to validate observed results. We identified a strong association with CNV at the T-cell receptor gamma and alpha loci (P < 1 × 10(-15)) in HCC cases when contrasted with controls. This variation appears to be somatic in origin, reflecting differences between T-cell receptor processing in lymphocytes from individuals with liver disease and healthy individuals that is not attributable to chronic hepatitis virus infection. Analysis of constitutional variation identified three susceptibility loci including the class II MHC complex, whose protein products present antigen to T-cell receptors and mediate immune surveillance. Statistical analysis of biologic networks identified variation in the "antigen presentation and processing" pathway as being highly significantly associated with HCC (P = 1 × 10(-11)). SNP analysis identified two variants whose allele frequencies differ significantly between HCC and LC. One of these (P = 1.74 × 10(-12)) lies in the PTEN homolog TPTE2.

CONCLUSION

Combined analysis of CNV, individual SNPs, and pathways suggest that HCC susceptibility is mediated by germline factors affecting the immune response and differences in T-cell receptor processing.

-509C>T polymorphism in the TGF-β1 gene promoter is not associated with susceptibility to and progression of colorectal cancer in Chinese

AIM

Colorectal cancer is common, accounting for nearly 10% of all cancers. Transforming growth factor-β1 (TGF-β1) is a pleiotropic cytokine that has been implicated in the pathogenesis of colorectal neoplasia. The most studied -509C>T polymorphism of TGF-β1 gene has been associated with various kinds of cancer. This study investigated the association between this genetic variant and the risk and/or progression of colorectal cancer.

METHOD

A case-control study was carried out of 150 colorectal cancer cases and 503 healthy controls. DNA was extracted from blood cell nuclear materials, and -509C>T polymorphism in the TGF-β1 gene promoter was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Colorectal cancer tissues (n = 70) were obtained from the studied cases for measurement of TGF-β1 mRNA expression levels. We also assessed the plasma TGF-β1 levels of cases (n = 88) and healthy subjects (n = 120).

RESULTS

The TGF-β1 producer genotype, -509TT, was not associated with an increased risk of colorectal cancer compared with other genotypes. Colorectal cancer patients especially those with a more aggressive disease behaviour were more frequently associated with C allele.

CONCLUSION

The results suggest that TGF-β1 -509C>T polymorphism is not associated with either an increased risk or progression of colorectal cancer.

Viral hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cause of cancer death worldwide. Despite recent advances in the diagnosis and treatment of HCC, its prognosis remains dismal. Infection with hepatitis B virus (HBV) and hepatitis C virus (HCV) are the major risk factors for HCC. Although both are hepatotropic viral infections, there are important differences between the oncogenic mechanisms of these two viruses. In addition to the oncogenic potential of its viral proteins, HBV, as a DNA virus, can integrate into host DNA and directly transform hepatocytes. In contrast, HCV, an RNA virus, is unable to integrate into the host genome, and viral protein expression has a more critical function in hepatocarcinogenesis. Both HBV and HCV proteins have been implicated in disrupting cellular signal transduction pathways that lead to unchecked cell growth. Most HCC develops in the cirrhotic liver, but the linkage between cirrhosis and HCC is likely multifactorial. In this review, we summarize current knowledge regarding the pathogenetic mechanisms of viral HCC.

Association of a variant in MIR 196A2 with susceptibility to hepatocellular carcinoma in male Chinese patients with chronic hepatitis B virus infection

MicroRNAs (miRNAs) are small noncoding RNAs with regulatory functions as tumor suppressors and oncogenes. Recent studies have implicated that the rs11614913 SNP in MIR196A2 was associated with susceptibility of lung cancer, congenital heart disease, breast cancer and shortened survival time of nonsmall cell lung cancer. To assess whether this polymorphism is associated with susceptibility to and clinicopathologic characteristics of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), a total of 560 patients with chronic HBV infection and 391 healthy volunteers were enrolled, and MIR196A2 polymorphism was genotyped by polymerase chain reaction-ligation detection reaction (PCR-LDR). In our study group, there was no significant association between MIR196A2 polymorphism and the risk of HBV-related HCC in all subjects, however, the risk of HCC was significantly higher with MIR196A2 rs11614913 CC genotype or C allele compared with those with the TT genotype or T allele in male patients. Furthermore, in a subsequent analysis of the association between this polymorphism and clinicopathologic characteristics, there was still no significant difference in both the distribution of genotype or allelic frequency. However, we observed that the T allele was significantly more frequent in male HCC patients with lymphatic metastasis. Our results suggested that MIR196A2 polymorphism was associated with susceptibility to HBV-related HCC in a male Chinese population.

+49G > A polymorphism in the cytotoxic T-lymphocyte antigen-4 gene increases susceptibility to hepatitis B-related hepatocellular carcinoma in a male Chinese population

Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is an important regulator and functions negatively in immune response. Its nonsynonymous polymorphism +49G > A (dbSNP: rs231775) has been linked to an elevated risk of T-cell-mediated autoimmune diseases, infectious diseases, and even carcinomas. Here, we examined the genotypes at rs231775 of 1003 subjects in a Han Chinese population to detect the association between this single-nucleotide polymorphism (SNP) and hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) susceptibility, including 375 HBV-related HCC patients, 209 non-HCC patients with HBV infection, and 419 healthy controls. Our results indicated a weak trend for the relationship between rs231775 and HBV-related HCC susceptibility, although the statistical level was not significant. However, a significant difference was identified in males between HBV-related HCC patients and healthy controls. The data revealed that the frequency of the A/A genotype was higher in patients compared with healthy controls (odds ratio [OR] = 1.79, 95% confidence interval [95% CI] 1.05-3.08). The G allele appeared to have a protective effect in developing HBV-related HCC. Subjects with the A allele had higher HCC susceptibility than those with the G allele (OR = 1.31, 95% CI 1.03-1.66). These results suggested that the A/A genotype and A allele of rs231775 increased the risk of developing HBV-related HCC in a male Chinese population.