Relationship between the polymorphism of tumor necrosis factor-α-308 G>A and susceptibility to inflammatory bowel diseases and colorectal cancer: a meta-analysis. Eur J Hum Genet. 2011;19:432-437. [PMID: 21248737 DOI: 10.1038/ejhg.2010.159]

Inflammatory Bowel Disease: A Comprehensive Analysis of Molecular Bases, Predictive Biomarkers, Diagnostic Methods, and Therapeutic Options

In inflammatory bowel diseases (IBDs), such as Crohn's disease (CD) and ulcerative colitis (UC), the immune system relentlessly attacks intestinal cells, causing recurrent tissue damage over the lifetime of patients. The etiology of IBD is complex and multifactorial, involving environmental, microbiota, genetic, and immunological factors that alter the molecular basis of the organism. Among these, the microbiota and immune cells play pivotal roles; the microbiota generates antigens recognized by immune cells and antibodies, while autoantibodies target and attack the intestinal membrane, exacerbating inflammation and tissue damage. Given the altered molecular framework, the analysis of multiple molecular biomarkers in patients proves exceedingly valuable for diagnosing and prognosing IBD, including markers like C reactive protein and fecal calprotectin. Upon detection and classification of patients, specific treatments are administered, ranging from conventional drugs to new biological therapies, such as antibodies to neutralize inflammatory molecules like tumor necrosis factor (TNF) and integrin. This review delves into the molecular basis and targets, biomarkers, treatment options, monitoring techniques, and, ultimately, current challenges in IBD management.

Ahmed M, Amle D. Molecular Determination of Tumor Necrosis Factor-alpha, Interleukin-8, Interleukin-10, and C-X-C Chemokine Receptor-2 Genetic Variations and their Association with Disease Susceptibility and Mortality in COVID-19 Patients

Background

Altered cytokine levels have been associated with poor outcomes among COVID-19 patients. TNF-α, IL-8 and IL-10 are key cytokines in COVID-19 pathogenesis, and CXCR-2 is a major chemokine receptor involved in inflammatory response. Polymorphisms in the genes of these proteins are proposed to influence disease outcomes. In this study, we aimed to find out the association of genetic polymorphisms in TNF-α, IL-8, IL-10 and CXCR-2 genes with susceptibility to and mortality of COVID-19.

Methods

The present case-control study was conducted on 230 subjects, among whom 115 were clinically diagnosed and RT-PCR-confirmed COVID-19 patients and 115 healthy control subjects. The polymorphisms in TNFα -308 G>A (rs1800629), IL-8 -251T>A (rs4073), CXCR2 +785 C>T (rs2230054) genes were detected by ARMS -PCR assay whereas for IL-10 (-1082 G>A), rs1800896 G>A allele-specific PCR assay was used and their association with COVID-19 susceptibility and mortality was estimated by multivariate analysis. The results were analyzed for risk of infection and mortality through different inheritance models.

Results

Frequencies of TNF-α rs1800629 GA, AA, IL-8 rs4073 TA, AA, IL-10 (-1082 G>A), rs1800896 GA and GG, and CXCR2 rs2230054 CT genotypes were significantly higher in COVID-19 patients compared to the control group (p < 0.05). Furthermore, COVID-19 patients had a higher frequency of the polymorphic A allele of TNF-α, the A allele of IL-8, the G allele of IL-10, and the T allele of CXCR2. The risk of susceptibility to COVID-19 was significantly associated with TNF-α rs1800629 GA, GA+AA genotypes and the A allele, IL-8 rs4073 TA, AA genotypes and A allele, IL-10 rs1800872 GA and CC genotypes and C allele, and CXCR2 rs2230054 CT and CT+CC genotypes. TNF-α-GA and AA genotypes and A allele, IL-8 TA and AA genotypes and A allele and CXCR-2 CC and CT genotypes have significant associations with mortality risk in COVID-19 patients, while GA and GG genotypes of the IL-10 are shown to confer significant protection against mortality from COVID-19.

Conclusion

The findings of this study provide important insights into the COVID-19 disease and susceptibility risk. The polymorphisms in TNFα -308 G>A (rs1800629), IL-8 -251T>A (rs4073), IL-10 (-1082 G>A), rs1800896 and CXCR2 +785 C>T (rs2230054) are associated with the risk of susceptibility to COVID-19 and with mortality in COVID-19 patients. Further studies with larger sample sizes are necessary to confirm our findings.

Lower Abundance and Impaired Function of CD71+ Erythroid Cells in Inflammatory Bowel Disease Patients During Pregnancy

BACKGROUND AND AIMS

CD71+ erythroid cells are enriched during pregnancy with immuno suppressive properties. We investigated the frequency and functionality of CD71+ erythroid cells in peripheral blood, cord blood, and placenta of inflammatory bowel disease [IBD] patients versus healthy controls [HCs]. We aimed to determine their role in IBD pathogenesis during pregnancy.

METHODS

Peripheral blood was collected at preconception, the first, second and third trimesters, and postpartum. Cord blood and placental tissues were collected at the time of birth. Cells from different specimens were subjected to immune-phenotyping and functional assays. CD71+ erythroid cells were purified for quantitative polymerase chain reaction [qPCR] analysis. Using an allogeneic mouse model of pregnancy, the effects of CD71+ erythroid cells depletion on intestinal homeostasis and dysbiosis was studied.

RESULTS

IBD patients had lower CD71+ erythroid cells during pregnancy compared with HCs. Placenta and cord blood CD71+ erythroid cells from IBD patients exhibited impaired functionality and expressed lower inhibitory molecules including VISTA, TGF-β, and reactive oxygen species [ROS]. Lower CD71+ erythroid cells were correlated with reduced regulatory T cells and increased immune-activation in IBD patients. Depletion of CD71+ erythroid cells in an allogeneic pregnancy model resulted in upregulation of TLRs, IL-6, and CXCL-1, and enhanced production of TNF-α, in intestinal tissues. In contrast, TGF-β gene expression was reduced. Excessive inflammatory response in the gut [e.g. TNF-α] affects intestinal integrity and CD71+ erythroid cells impact on the gut's bacterial composition.

CONCLUSIONS

Reduced frequency and/or impaired functionality of CD71+ erythroid cells during pregnancy may predispose IBD patients to a more pro-inflammatory milieu in their gastrointestinal tract, characterised by lower Tregs, higher IL-6, and TNF-α, and dysbiosis.

Associations between single-nucleotide polymorphisms and inflammatory bowel disease-associated colorectal cancers in inflammatory bowel disease patients: a meta-analysis

PURPOSE

To assess the correlation between single-nucleotide polymorphisms (SNPs) and inflammatory bowel disease (IBD)-associated colorectal cancer (CRC) in IBD patients.

METHODS

A systematic search of PubMed, EmBase, and Cochrane databases was performed. Five genetic models (allelic, dominant, recessive, heterozygous and homozygous models) were used to analyze the associations, and trial sequential analysis was used to analyze the robustness of the results.

RESULTS

We collected and analyzed the results of seven trials including a total of 2287 patients in our meta-analysis. A total of 8 SNPs were tested in IBD patients. For rs1800629 of TNF-α, the allelic model showed that polymorphism at this locus significantly increased the risk of IBD-associated CRC in IBD patients (OR 4.45, 95% CI 3.18-6.21, P < 0.001). The results also showed a significant association between rs1800629 and an IBD-associated CRC population (heterozygous model: OR 4.335, 95% CI 2.329-8.069, P < 0.001; homozygous model: OR 11.5, 95% CI 2.498-52.592, P = 0.002; dominant model: OR 4.986, 95% CI 2.754-9.026, P < 0.001; recessive model: OR 7.208, 95% CI 1.588-32.72, P = 0.01). Other studies have found that mutation of rs1143627 of IL1B (allelic model: OR 2.97; 95% CI 1.74-5.05, P < 0.001) and rs1050152 of OCTN1 (allelic model: OR 1.637, 95% CI 1.078-2.485, P = 0.021) increased the proportion of IBD-associated CRC in the population. Moreover, there were significant associations between IBD-associated CRC and ITLN rs2274910, gene desert rs1551398 and rs4871611, FCGR2A rs1801274, and S100-Z rs7712957 in the allelic model.

CONCLUSION

Associations between SNPs and the proportion of IBD-associated CRC in IBD patients were examined, and further investigation of additional SNPs and their association with the risk of morbidity is needed.

Inflammatory Bowel Disease: Influence and Implications in Reproduction

The incidence and prevalence of inflammatory bowel disease (IBD) continues to rise with time, signifying its emergence as a global disease. Clinical onset of IBD, comprising Crohn's disease and ulcerative colitis, typically occurs before or at peak reproductive age. Although active disease in female patients is associated with reduced fertility and adverse obstetric outcomes in pregnancy, the molecular mechanisms underlying this altered reproductive course, and its impact on IBD transmission to offspring, remain poorly understood. Clinical and experimental studies have now begun to elucidate the hormonal, environmental, and microbial factors that modulate immune-reproductive cross talk in IBD and define their impact on maternal health, fetal development, and heritability of disease risk. Evolving insight into maternal-fetal imprinting in IBD has important implications for patient counseling and disease management during pregnancy and may help predict clinical outcomes for both mother and child.

Systematic meta-analyses and field synopsis of genetic and epigenetic studies in paediatric inflammatory bowel disease

We provide a comprehensive field synopsis of genetic and epigenetic associations for paediatric Inflammatory Bowel Disease (IBD). A systematic review was performed and included 84 genetic association studies reporting data for 183 polymorphisms in 71 genes. Meta-analyses were conducted for 20 SNPs in 10 genes of paediatric Crohn’s disease (CD) and for 8 SNPs in 5 genes of paediatric ulcerative colitis (UC). Five epigenetic studies were also included, but formal meta-analysis was not possible. Venice criteria and Bayesian false discovery probability test were applied to assess the credibility of associations. Nine SNPs in 4 genes were considered to have highly credible associations with paediatric CD, of which four variants (rs2066847, rs12521868, rs26313667, rs1800629) were not previously identified in paediatric GWAS. Differential DNA methylation in NOD2 and TNF-α, dysregulated expression in let-7 and miR-124 were associated with paediatric IBD, but not as yet replicated. Highly credible SNPs associated with paediatric IBD have also been implicated in adult IBD, with similar magnitudes of associations. Early onset and distinct phenotypic features of paediatric IBD might be due to distinct epigenetic changes, but these findings need to be replicated. Further progress identifying genetic and epigenetic susceptibility of paediatric IBD will require international collaboration, population diversity and harmonization of protocols.

TNF-α -308 G > A (rs1800629) Polymorphism is Associated with Celiac Disease: A Meta-analysis of 11 Case-Control Studies

Celiac disease (CD) remains one of the most significant autoimmune diseases worldwide. The pathogenesis of CD is not clearly understood and is probably attributed to genomic variations and host genetic make-up. Case-control and cohort studies of the association between the TNF-α -308 G > A (rs1800629) polymorphism and CD susceptibility have yielded inconsistent results. In this study, PubMed, EMBASE, and Google Scholar web-databases were searched for pertinent reports showing association of TNF-α -308 G > A gene with CD risk. A total of eleven reports involving 1774 controls and 1147 CD cases were included. Significant associations in four genetic models, viz. variant allele (A vs. G: p = 0.001; OR = 2.051, 95% CI = 1.452-2.895), variant homozygous (AA vs. GG: p = 0.001; OR = 6.626, 95% CI = 3.569-12.300), recessive (AA vs. GG + AG: p = 0.001; OR = 4.766, 95% CI = 3.177-7.152) and dominant (AA + AG vs. GG: p = 0.008; OR = 1.910, 95% CI = 1.181-3.088) were found in comparison with wild type homozygous GG genotype. However, heterozygous genetic model did not show any association. Sensitivity analysis revealed stable and statistically robust results. Our results suggest that TNF-α -308 G > A gene polymorphism significantly contributes to CD susceptibility.

Association of tumor necrosis factor-α and -β gene polymorphisms in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a complex, multifactorial, chronic inflammatory disorder of the gastrointestinal tract in which immune dysregulation caused by genetic and/or environmental factors plays an important role. The aim of this case–control study was to evaluate the association of tumor necrosis factor-alpha (TNF-α) (308) and -β (+252) polymorphisms with susceptibility of IBD. A total of 379 Saudi subjects including 179 IBD patients (ulcerative colitis (UC) =84 and Crohn’s disease (CD) =95) and 200 age- and sex-matched healthy controls were recruited. TNF-α and TNF-β genes were amplified using an amplification refractory mutation systems polymerase chain reaction methodology to detect TNF-α (−308) and -β (+252) polymorphisms. The frequency of the GA genotype of TNF-α (−308G/A) was higher, and the frequencies of the GG and AA genotypes were significantly lower in IBD patients compared with those in controls, indicating that genotype GA-positive individuals are susceptible to IBD and that the GG and AA genotypes exert a protective effect. The frequency of allele A of TNF-α (−308G/A) was significantly higher and that of allele G was lower in IBD patients compared with those in controls, indicating an association of allele A with IBD risk in Saudi patients. On stratification of IBD patients into UC and CD, an almost similar pattern was noticed in both the groups. The results of TNF-β (+252A/G) polymorphisms showed a significant increase in the frequency of the GG genotype in IBD patients, suggesting a positive association of GG genotype with IBD risk. On stratification of IBD patients into UC and CD, the genotype GG of TNF-β was associated with susceptibility risk to UC but not CD. The frequencies of alleles and genotypes of both TNF-α and-β polymorphisms are not affected by sex or type of IBD (familial or sporadic). TNF-α (−308G/A) and TNF-β (+252A/G) polymorphisms are associated with risk of developing IBD in Saudi population.

Association of inflammatory cytokine gene polymorphisms with inflammatory bowel disease in a Moroccan cohort

The purpose of this study was to investigate whether common variants in inflammatory and immune response genes influence inflammatory bowel disease (IBD) risk among Moroccan patients. Using a candidate gene approach, 10 single-nucleotide polymorphisms mapping on six genes (MIF_rs755622, TNFA_rs1800629, IL6_rs2069840, IL6R_rs2228145, IL6ST_rs2228044, IL17A (rs2275913, rs4711998, rs7747909, rs8193036, rs3819024)) were assessed in 510 subjects grouped in 199 IBD and 311 healthy controls. Genotyping was performed with the TaqMan allelic discrimination technology. The results were analyzed using PLINK software. The frequency of allele A for TNFA rs1800629 was significantly higher in ulcerative colitis (UC) patients compared with controls (30.16 vs 16.72%; P=0.0005; odds ratio (OR)=2.15; 95% confidence interval (CI)=1.39-3.32). Statistically significant association to UC was also found under dominant AA+AG vs GG (OR=1.85, 95% CI=1.07-3.21; P=0.02) and recessive models (OR=8.38; 95% CI=2.86-24.53; P=0.0001). In the same way, an association of TNFA rs1800629 variant was observed with IBD under recessive model AA vs AG+GG (OR=4.10; 95% CI=1.56-10.76; P=0.004). No evidence of significant associations was found for the remaining investigated polymorphisms. Our data suggest that TNFA gene promoter polymorphism participates in determining IBD susceptibility in Moroccan patients.

Variations in inflammatory genes as molecular markers for prediction of inflammatory bowel disease occurrence

OBJECTIVE

Research on inflammatory bowel disease (IBD) has highlighted genes involved in the regulation of inflammatory responses as contributors to disease pathogenesis. This study aimed to evaluate the associations between IBD and variations in NOD2, TLR4, TNF-α, IL-6, IL-1β and IL-1RN genes, and to use the genetic data obtained in predictive modeling.

METHODS

A total of 167 IBD patients and 101 healthy controls were genotyped by polymerase chain reaction-restriction fragment length polymorphism. Using the genotype data attained as the input to various classification algorithms, IBD prediction models were designed. The area under the receiver operating characteristic curve (AUROC) was used to measure their performance.

RESULTS

Significant associations were found between Crohn's disease (CD) and minor NOD2 variants, as well as TLR4 299Gly, TNF-α G-308A, IL-6 G-174C and IL-1RN VNTR A2 variants, while ulcerative colitis (UC) was associated only with IL-1RN VNTR A2 variants. CD and UC showed highly significant difference in the allelic distribution of TNF-α G-308A, where the A allele was found to be related to CD, and the G allele to UC. A combined effect of patients' gender and TLR4 variants was observed among CD patients. When all analyzed genotype and gender data were used, prediction performance achieved a maximum AUROC of 0.690 for CD and 0.601 for UC dataset.

CONCLUSION

Variations in the genes involved in immune regulation are genetic factors of importance in IBD susceptibility that could potentially be used as predictors of disease development.

Polymorphisms of tumor necrosis factor alpha in Middle Eastern population with colorectal cancer

Tumor necrosis factor-alpha (TNF-α) contributes in inflammation and has been implicated in the development of colorectal cancer (CRC). Single nucleotide polymorphisms (SNPs) in TNF-α promoter could affect the risk of CRC by regulating TNF-α production. This is the first study to investigate TNF-α SNPs in a Middle Eastern population. In this study, we examined three SNPs in TNF-α for association with CRC. One hundred CRC patients and 100 controls were genotyped for TNF-α -308, -238, and -857 using TaqMan allelic discrimination assay. The TNF-α -238 (G/A) genotype was significantly associated with high risk of CRC (p = 0.003552). The distribution of three genotypes of -238 G/A was significantly different between the controls and CRC patients even after Bonferroni’s correction. The AA genotype of -238 G/A SNP was observed at considerably higher proportion (13 %) in CRCs compared to controls (1 %). Additionally, similar to genotypes, the allelic frequencies of -238 G/A were significantly different between the CRC cases and controls (odds ratios (OR) = 7.647, χ² = 18.50, p = 0.00002). The genotype frequencies of -308 and -857 were not notably different between the cases and controls. TNF-α -238A may be useful as a screening marker to identify individuals prior to their acquiring CRC in the Saudi population although, further validations in larger cohorts are needed.

Molecular Alterations of Colorectal Cancer with Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an important etiologic factor in the development of colorectal cancer (CRC). The risk of CRC begins to increase 8 or 10 years after the diagnosis of IBD. This type of cancer is called colitis-associated CRC (CA-CRC). The molecular pathogenesis of inflammatory epithelium might play a critical role in the development of CA-CRC. Genetic alterations detected in CA-CRC such as genetic mutations, microsatellite instability, and DNA hypermethylation are also recognized in sporadic CRC; however, there are differences in the timing and frequency of molecular events between CA-CRC and sporadic CRC. Interaction between gene-environmental factors, including inflammation, lifestyle, psychological stress, and prior appendectomy, might be associated with the etiopathology of IBD. The mucosal inflammatory mediators, such as oxidant stress, free radicals, and chemokines, may cause the genetic alterations. Understanding the molecular mechanisms of CA-CRC might be important to develop clinical efficacies for patients with IBD. This review discusses the molecular characteristics of CA-CRC, especially ulcerative colitis-associated CRC, including clinical features, signaling pathways, and interactions between genetic alterations and environment involved in inflammatory carcinogenesis.

Association of genetic polymorphisms with osteosarcoma risk: a meta-analysis

Osteosarcoma (OS) is the most common pediatric and adult bone malignancy worldwide. Genetic polymorphisms may play critical roles in the development of OS. However, there present inconclusive results. The current study was to investigate the role of genetic polymorphisms in OS risk. Electronic databases were searched for relevant studies published between 2000 and 2014. The odds ratio (OR) with its 95% confidence interval (CI) were employed to estimate the associations. Total 7 studies containing 911 OS patients and 1145 matched controls were included. Our results found that CTLA-4 +49A/G G allele and TGF-β1 29T/C C allele were more frequent in OS patients than that in controls, indicating that these two alleles were significantly associated with increased the risk of OS (G vs. A: OR = 1.36, 95% CI = 1.13-1.64, P = 0.001; C vs. T: OR = 1.49, 95% CI = 1.17-1.90, P = 0.001) in a fixed-effect model. This significant relationship was also found under other three genetic models in both variants (P<0.05). While no association was found between TNF-α -308G/A or TNF-β +252A/G polymorphism and OS risk. In conclusion, our results demonstrated that CTLA-4 +49A/G and TGF-β1 29T/C variants were significantly associated with OS susceptibility. Although number of included studies is small, several polymorphisms appearing to significantly influence the OS risk should be focused. Moreover, further studies with gene-gene and gene-environmental interactions should be considered.

Sequence variants of peroxisome proliferator-activated receptor-gamma gene and the clinical courses of patients with end-stage renal disease

Background. PPAR-γ single nucleotide polymorphisms (SNPs) reportedly play an important role in determining metabolic risk among diverse population. Whether PPAR-γ SNPs affect the clinical courses in ESRD patients is unknown. Methods. From a multicenter cohort, we identified 698 patients with prevalent ESRD between 2002 and 2003, and other 782 healthy subjects as control. Two PPAR-γ SNPs, Pro12Ala (rs1801282) and C161T (rs3856806), were genotyped and their association with ESRD was examined. Both groups were prospectively followed until 2007, and the predictability of genotypes for the long-term survival of ESRD patients was analyzed. Results. After multivariable-adjusted regression, GG genotype of Pro12Ala was significantly more likely to associate with ESRD (P < 0.001) among patients with non-diabetes-related ESRD. Cox's proportional hazard regression showed that both Pro12Ala and C161T polymorphisms were significant predictors of mortality in ESRD patients with DM (Pro12Ala: GG versus other genotypes, hazard ratio [HR] <0.01; P < 0.001; for C161T, CC versus TT genotypes, HR 2.86; P < 0.001; CT versus TT genotypes, HR 1.93; P < 0.001). Conclusion. This is the first and largest study to evaluate PPAR-γ SNPs in ESRD patients. Further mechanistic study is needed to elucidate the role of PPAR-γ among ESRD patients.

Colorectal cancer severity and survival in correlation with tumour necrosis factor-alpha

Colorectal cancer (CRC) development is strongly associated with innate immune mechanisms and intestinal inflammation. The aim of the study was to investigate the pre-operative serum levels of TNF-α and its correlation with cancer progression and survival in CRC patients taking into account the genotype of -308G/A promoter polymorphism in TNF-α gene (rs1800629). TNF-α -308G/A genotypes of 119 CRC cases and 177 no CRC controls were determined by restriction fragment length polymorphism assay (RFLP-PCR). TNF-α serum levels were measured by enzyme-linked immunosorbent assay (ELISA). Although no significant differences in allele and genotype frequencies between CRC and controls were observed, it should be noted that the minor allele-A and its homozygous genotype were overrepresented among CRC. In addition, allele-A was more frequent in early CRC patients compared to advanced cases. TNF-α serum level was significantly higher in CRC patients than in controls (36.1 ± 8.4 pg/mL vs. 18.66 ± 11 pg/mL; p = 0.0000001). In the subgroup analysis by tumour-node-metastasis stages, the highest TNF-α level was found in stage IV (42.7 ± 12.5 pg/mL) and was significantly elevated compared to earlier stages of CRC and controls. The survival rate of CRC patients with low TNF-α serum level, estimated as median survival, was significantly higher than that of patients with high levels of TNF-α (38.4 vs. 7.761 months; log rank test p = 0.00015) In conclusion, we can affirm that TNF-α affects tumour development along with disease progression which has an impact on the survival of CRC.

Tumor necrosis factor-α 238 G/A polymorphism and risk of hepatocellular carcinoma: evidence from a meta-analysis

BACKGROUND

Tumor necrosis factor-α (TNF-α) plays a very important role in the development and progression of cancer. Many epidemiological studies have evaluated associations between the TNF-α 238 G/A polymorphism and hepatocellular carcinoma (HCC) risk, but the published data are inconclusive. Therefore, we performed the present meta-analysis.

METHODS

Electronic searches of several databases were conducted for all publications on the association between TNF-α 238 G/A polymorphism and HCC through July 2012. Asummary odds ratio (OR) with its 95% confidence interval (CI) were calculated to evaluate the strength of this association.

RESULTS

Eleven case-control studies with a total of 1,572 HCC cases and 1,875 controls were finally included in this meta-analysis. Overall, the TNF-α 238 G/A polymorphism was significantly associated with increased risk of hepatocellular carcinoma in three genetic comparison models (For A versus G: OR 1.32, 95%CI 1.04-1.69, P = 0.02, I2 = 40%; for AG versus GG: OR 1.32, 95%CI 1.02-1.71, P = 0.03, I2 = 40%; for AA/AG versus GG: OR 1.33, 95%CI 1.03-1.72, P = 0.03, I2 = 41%) when all studies were pooled. Subgroup analysis by ethnicity further showed that there was a significant association between the TNF-α 238 G/A polymorphism and risk of HCC in Asians under three genetic comparison models (For A versus G: OR 1.30, 95%CI 1.00-1.68, P = 0.05, I2 = 45% for AA/AG versus GG: OR 1.31, 95%CI 1.00-1.71, P = 0.05, I2 = 46%).

CONCLUSIONS

This meta-analysis provided convincing evidence that the TNF-α 238 G/A polymorphism is associated with increased susceptibility to HCC. However, more well-designed studies with large sample size are needed to validate this association in Caucasians.

Colorectal cancer in inflammatory bowel disease: The risk, pathogenesis, prevention and diagnosis

Patients with inflammatory bowel disease (IBD) are at increased risk for developing colorectal cancer (CRC), although the overall incidence of IBD-associated CRC has been diminishing in recent decades in western countries. As demonstrated in previous studies, the risk of CRC in IBD increases with longer duration, extent of colitis, a familial history of CRC, coexistent primary sclerosing cholangitis, and the degree of inflammation. The pathogenesis of CRC in IBD is poorly understood. Similar to sporadic CRC, IBD-associated CRC is a consequence of sequential episodes of genomic alteration. Multiple inter-related pathways, including immune response by mucosal inflammatory mediators, oxidative stress, and intestinal microbiota, are also involved the pathogenesis of IBD-associated CRC. Continuing colonic inflammation appears to be a factor in the development of CRC; therefore, anti-inflammatory agents such as 5-aminosalicylate compounds and immune modulators have been considered as potential chemopreventive agents. Colonoscopic surveillance is widely accepted as being effective in reducing the risk of IBD-associated CRC, although no clear evidence has confirmed that surveillance colonoscopy prolongs survival in patients with extensive colitis. The traditional recommendation has been quadrantic random biopsies throughout the entire colon; however, several guidelines now have endorsed chromoendoscopy with a target biopsy because of increasing diagnostic yields and reduced workloads for endoscopists and pathologists. New technologies such as narrow band imaging, confocal endomicroscopy, and autofluorescence imaging have not yet been confirmed as surveillance strategies in IBD.

Inflammatory bowel disease and mesenchymal stem cells

Inflammatory bowel disease (IBD) is a group of chronic non-specific inflammatory disease with unknown etiology; it is associated with genetic factors, immune factors, intestinal flora, infection, and other factors. In recent years, mesenchymal stem cells (MSCs) have attracted more and more attention in the treatment of IBD, and the therapeutic effects may be associated with their antiinflammatory and immunomodulatory effects as well as intestinal epithelium reconstruction. In this article, we will review the causes of IBD and possible mechanisms of MSCs in treating IBD.

Contribution of NKX2-3 polymorphisms to inflammatory bowel diseases: a meta-analysis of 35358 subjects

Polymorphisms in NKX2-3 gene have been inconsistently associated with Crohn's disease (CD) and ulcerative colitis (UC). To generate large-scale evidence on whether NKX2-3 polymorphisms are associated with CD or UC susceptibility we have conducted a meta-analysis of 17 studies involving 17329 patients and 18029 controls. A significantly increased CD or UC risk was observed in persons carrying a G allele at rs10883365 polymorphism (A/G) compared with those with a A allele. (OR = 1.226, 95%CI: 1.177–1.277 and OR = 1.274, 95%CI: 1.175–1.382 respectively). In the subgroup analysis, a significantly increased CD risk was found in both Europeans and Asians. For rs11190140 polymorphism (C/T) and CD risk, the risk estimate for the allele contrast was OR = 1.201 (1.136–1.269). This meta-analysis provided a robust result that persons with a G or T allele may have a moderately increased risk of CD, and suggested that rs10883365 polymorphism was also a candidate gene polymorphism for UC susceptibility.

TNF-alpha gene polymorphisms in Iranian Azari Turkish patients with inflammatory bowel diseases

CONTEXT

Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory diseases of the bowel (IBD) whose causes are not fully known. Emerging data indicate that alterations in cytokine synthesis may play a role in IBD pathogenesis.

AIMS

We aimed to determine the association between tumor necrosis factor-alfa (TNFα) promoter polymorphisms (at positions - 308 and - 1031) and susceptibility to IBD among Iranian Azari Turkish patients.

SETTINGS AND DESIGN

One hundred and one patients with IBD and 100 healthy subjects were analyzed.

MATERIALS AND METHODS

Both polymorphisms in the promoter region of the TNFα gene at positions -1031T/C and -308G/A were detected by polymerase chain reaction-restriction fragment length polymorphism assay. All statistical analyses were calculated with SPSS for Windows 16.0. The Fisher's exact test was used to test for departure from Hardy-Weinberg equilibrium of the genotype frequencies (P > 0.05).

RESULTS

The allele frequency of the TNFα-308G and -1031T were higher in IBD patients but did not reach statistical significance. However, the homozygous TT genotype for the SNP-1031 T > C was significantly higher in UC patients than in healthy controls (P = 0.01) and the heterozygous CT genotype for the SNP -1031 T > C was significantly lower in UC patients than in healthy controls (P = 0.03).

CONCLUSIONS

The TNFα-1031 T allele confers a significant risk for developing UC in Iranian Azeri Turkish patients. Also the frequency of TNFα-1031 C allele was considerably low among patients with UC and it may have protective role among them (OR = 0.43; P = 0.01).

TNF-α gene promoter polymorphisms and risk of venous thromboembolism in gastrointestinal cancer patients undergoing chemotherapy

BACKGROUND

TNF-α has been proposed as a predictive factor for venous thromboembolism (VTE). Genetic polymorphisms could regulate TNF-α production. However, the relationship between TNFA gene variants and VTE is not clarified. This study aims to investigate the predictive role of five different TNFA gene promoter SNPs, or their haplotype combination(s), for a first VTE episode in gastrointestinal cancer out-patients treated with chemotherapy.

PATIENTS AND METHODS

Serum TNF-α levels and TNFA -863C/A, -857C/T, -376G/A, -308G/A and -238G/A gene promoter polymorphisms were retrospectively evaluated in 314 subjects, including 157 controls and 157 Caucasian patients with histologically diagnosed GI cancers beginning chemotherapy delivery (5-fluorouracil either as monotherapy or in combination with platinum compounds or irinotecan).

RESULTS

Haplotype analysis showed that a five-loci haplotype (CTGGG haplotype) has higher frequency in GI cancer patients who developed VTE (n = 15) during chemotherapy [odds ratio = 2.7, 95% confidence interval (CI) 1.04-7.11, P = 0.04]. GI patients who remained VTE-free did not differ in CTGGG haplotype frequency from controls. No association was observed between serum TNF-α levels and TNFA haplotype, but both were independent predictors of VTE. Approximately 20% of GI cancer patients carrying the CTGGG haplotype developed VTE compared with 4% of the remaining 101 patients (hazard ratio = 5.6, 95% CI 1.8-17.6, P = 0.003).

CONCLUSION

These results suggest that TNFA might represent a candidate gene contributing to VTE pathogenesis in GI cancer patients and suggest that VTE risk during chemotherapy might be genetically identified. Validation studies are needed for translation into clinical practice.

The association between tumor necrosis factor alpha promoter polymorphisms and ankylosing spondylitis: a meta-analysis

BACKGROUND

Studies investigating the association between tumor necrosis factor (TNF)-alpha promoter polymorphisms and ankylosing spondylitis have reported conflicting results. We here performed a meta-analysis based on the evidence currently available from the literature to make a more precise estimation of this relationship.

METHODS

We performed a systematic search of the National Library of Medline and Embase databases before January 2013. This meta-analysis included 14 case-control studies, which included 1607 ankylosing spondylitis cases and 1910 controls.

RESULTS

The combined results based on all studies showed that ankylosing spondylitis cases had a significantly lower frequency of -308GA [OR (codominant model)=0.81, 95% CI=0.66, 0.99, P=0.04], -857CT [OR (codominant model)=0.55, 95% CI=0.32, 0.94, P=0.03], -863AA [OR (codominant model)=0.11, 95% CI=0.01, 0.94, P=0.04], -863CA [OR (codominant model)=0.32, 95% CI=0.18, 0.58, P<0.001], and -1031TC [OR (codominant model)=0.44, 95% CI=0.25, 0.77, P=0.004] genotype. However, ankylosing spondylitis cases had a significantly higher frequency of -238AA [OR (recessive model)=7.43, 95% CI=3.66, 15.05, P<0.001] and -850TT [OR (recessive model)=2.49, 95% CI=1.16, 5.34, P=0.02; OR (codominant model)=2.83, 95% CI=1.28, 6.25, P=0.01] genotype. In the subgroup analysis by race, we found that ankylosing spondylitis cases had a significantly higher frequency of -238AA [OR (recessive model)=7.43, 95% CI=3.66, 15.05, P<0.001] genotype in Caucasians and lower frequency of -857CT [OR (codominant model)=0.53, 95% CI=0.30, 0.94, P=0.03] in Asians.

CONCLUSIONS

Our meta-analysis suggests that TNF-alpha promoter polymorphisms at positions -238, -308, -850, -857, -863 and -1031 could have a small influence on ankylosing spondylitis susceptibility. But there is a lack of association of the TNF-alpha-376G/A and -646G/A polymorphisms with ankylosing spondylitis.

A systemic assessment of the association between tumor necrosis factor alpha 308 G/A polymorphism and risk of cervical cancer

Tumor necrosis factor alpha (TNF-α) is a multifunctional cytokine which plays an important role in the human immune response against various pathogens, and there may be a relationship between TNF-α 308 G/A polymorphism and cervical cancer risk. We performed a meta-analysis to get a systemic assessment of the association between TNF-α 308 G/A polymorphism and cervical cancer risk. Electronic searches of PubMed, Embase, and Web of Science were performed for all publications on the association between TNF-α 308 G/A polymorphism and cervical cancer risk through October 26, 2012. The pooled odds ratios (ORs) with their 95 % confidence interval (95 % CIs) were calculated to assess the association. Fifteen studies with a total of 3,743 cervical cancer cases and 4,096 controls were finally included into the meta-analysis. Overall, TNF-α 308 G/A polymorphism was significantly associated with increased risk of cervical cancer under three main genetic comparison models (A vs. G, OR 1.20, 95 % CI 1.02-1.42, P=0.03; AA vs. GG, OR 1.31, 95 % CI 1.00-1.72, P=0.048; AA vs. GG/GA, OR 1.30, 95 % CI 1.00-1.71, P=0.05). Subgroup analysis by ethnicity further showed that there was a significant association between TNF-α 308 G/A polymorphism and increased risk of cervical cancer in Asians (AA vs. GG, OR 1.83, 95 % CI 1.05-3.20, P=0.034; AA vs. GG/GA, OR 1.84, 95 % CI 1.05-3.22, P=0.032). The meta-analysis suggests that TNF-α 308 G/A polymorphism is associated with increased risk of cervical cancer, and TNF-α 308 G/A mutant allele A is a risk factor of cervical cancer.

MTHFR C677T polymorphism was an ethnicity-dependent risk factor for cervical cancer development: evidence based on a meta-analysis

INTRODUCTION

Many studies have studied the associations between 5, 10-methylene tetrahydrofolate reductase (MTHFR) polymorphisms and susceptibilities of cervical cancer and cervical intraepithelial neoplasia (CIN); however, the results were inconsistent. The aim of this study was to further assess the relationships by the method of meta-analysis.

MATERIALS AND METHODS

Two investigators independently searched the PubMed, Embase, Wang Fang (Chinese database) and CNKI (China National Knowledge Infrastructure), with latest update to July 1st, 2011. The pooled odds ratio (OR) and 95 % confidence interval (95 % CI) were used to assess the strength of the associations by using fixed- or random-effect model.

RESULTS

Ten case-control studies were included in this meta-analysis including a total of 1,803 cervical cancer or CIN cases and 2,363 controls. Pooled analyses showed that T allele of MTHFR C677T was significantly associated with increased CIN risk [OR (95 % CI): 1.28 (1.03-1.50) for CT vs. CC], especially for low-grade CIN risk. In addition, MTHFR C677T rather than A1298C polymorphism was associated with risk of cervical cancer. Stratifying analyses for ethnicity indicated that T allele of MTHFR C677T was associated with increased cervical cancer risk for Asian [OR (95 % CI): 1.56 (1.17-2.08) for TT vs. CC; 1.53 (1.19-1.96) for TT vs. C carriers] while decreased risk for Caucasian [OR (95 % CI): 0.63 (0.45-0.89) for TT vs. CC; 0.66 (0.56-0.79) for T carriers vs. CC].

CONCLUSION

This meta-analysis suggested that there was no association between MTHFR A1298C polymorphism and cervical cancer risk. However, MTHFR C677T was an ethnicity-dependent risk factor for cervical cancer occurrence. In addition, T allele of C677T was significantly associated with risk of low grade of CIN incidence. Because of modest limitations of our study, well-designed studies with large sample size were needed to confirm our findings in the future.

Overview of molecular pathways in inflammatory bowel disease associated with colorectal cancer development

Patients with long-standing inflammatory bowel disease (IBD) are at a higher risk of developing colorectal cancer (CRC). This risk increases with the longer duration of colitis, greater extent of inflammation, a family history of CRC, severity of bowel inflammation, and a coexistent primary sclerosing cholangitis. The cornerstone for comprehending the development of CRC in IBD and hence early detection is based on the understanding of the molecular pathways of IBD itself. At a molecular level, the pathogenesis of CRC is related to understanding the inflammatory changes and involves multiple inter-related pathways including (i) genetic alterations (e.g. chromosomal and microsatellite instability and hypermethylation), (ii) mucosal inflammatory mediators (e.g. COX-2, interleukin-6, interleukin-23, tumor necrosis factor-α, nuclear factor-κB, and chemokines), (iii) changes in the expression of receptors on the epithelial cells, and (iv) oxidant stress, mucosal breakdown, and intestinal microbiota. The aim of this review is to provide an evidence-based approach for the role of chronic inflammatory mechanisms and the molecular basis of these mechanisms in the development of CRC. Therefore, understanding the molecular basis of CRC is an important step for the identification of new biomarkers that can help in the early detection of CRC in these patients.

Opioid genetics: the key to personalized pain control?

There are now several strong opioids available to choose from for the relief of moderate to severe pain. On a population level, there is no difference in terms of analgesic efficacy or adverse reactions between these drugs; however, on an individual level there is marked variation in response to a given opioid. The genetic influences to this variation are complex, and although current research has shown some promising results, these have not been replicated across larger studies and as such the ultimate aim of personalized prescribing remains elusive. If personalized prescribing could be achieved this would have a major impact at an individual level to facilitate safe, effective and rapid symptom control. This review presents some of the recent positive advances in opioid pharmacogenetic studies, focusing on associations between candidate genes and the three main elements of opioid response: analgesic, upper gastrointestinal and central adverse reactions.

Polymorphisms of interleukin-1 and interleukin-6 genes on the risk of ischemic stroke in a meta-analysis

Many epidemiological studies have investigated the associations between polymorphisms of interleukin-1 (IL1) and interleukin-6 (IL6) genes and risk of ischemic stroke (IS), but no conclusions are available because of conflicting results. The aim of this study was to assess the relationships by meta-analysis. The databases of Pubmed, Embase and Wangfang, updated to August 1st, 2011, were retrieved. Odds ratio (OR) and corresponding 95% confidence interval (95% CI) as effect size were calculated by a fixed- or random-effect model. In total, three case-control studies for IL1α-889C/T, eight studies for IL1β-511C/T, eight studies for IL1-Ra and seven studies for IL6-147G/C were included in this meta-analysis. Combined analysis indicated that IL1β-511C/T polymorphism was not overall associated with risk of IS [OR (95% CI)=1.22 (0.85-1.87) for TT vs. CC]. However, when subgroup analyses for countries were conducted, the results indicated that T allele was associated with increased risk of IS for Polish and associated with a trend of increased risk of IS for Chinese although it did not reach statistical significance [TT vs. CC: OR (95% CI)=1.97 (1.22-3.17) for Polish and 1.40 (0.99-1.99) for Chinese]. In addition, overall and subgroup analyses indicated that IL1α-889C/T, IL1-Ra and IL6-147G/C polymorphisms were also not associated with risk of IS [OR (95% CI)=1.21 (0.86-1.70) for TT vs. CC of IL1α-889C/T, 1.22 (0.85-1.75) for RN2/RN2 vs. RN1/RN1 for IL1-Ra and 1.09 (0.84-1.40) for G carriers vs. C carriers for IL6-147G/C]. This study inferred that IL1β-511C/T polymorphism might be moderately associated with increased risk of IS, but no sufficient evidence was available to support any associations between IL1-Ra and IL6-147G/C polymorphisms and IS. We could not draw a conclusion between IL1α-889C/T polymorphism and risk of IS based on the limited data, and further large sample-sized studies were required.

Contribution of NAD(P)H quinone oxidoreductase 1 (NQO1) Pro187Ser polymorphism and risk of colorectal adenoma and colorectal cancer in Caucasians: a meta-analysis

BACKGROUND AND AIMS

The effects of polymorphism of NAD(P)H quinone oxidoreductase 1 (NQO1 Pro187Ser, rs1800566) on the risks of colorectal adenoma and cancer have been widely studied and results remain controversial. Therefore, the aim of this meta-analysis was to quantitatively assess the relationships.

METHODS

Databases of Medline, Embase and Wanfang were retrieved until May 15, 2011. Pooled odds ratio (OR) and 95% confidence interval (95% CI) as effect sizes were calculated by using fixed- or random-effect model. Cochrane Q-test was used to explore between-study heterogeneity; p <0.10 indicated statistical significance.

RESULTS

A total of 12 case-control studies with 11,700 individuals (including 5528 cases and 6172 controls) were included in this meta-analysis. Of these studies, four studies conducted in Caucasian populations were for colorectal adenoma, and eight studies were for colorectal cancer. NQO1 187Ser allele was significantly associated with increased risk of colorectal adenoma in co-dominant and dominant comparison models (OR = 1.07, 95% CI = 1.04-1.32 for ProSer vs. ProPro and OR = 1.19, 95% CI = 1.06-1.33 for Ser carries vs. ProPro), without between-study heterogeneity. Overall, NQO1 Pro187Ser was not associated with risk of colorectal cancer, without between-study heterogeneity. Subgroup analyses indicated that Ser allele was significantly associated with increased risk of colorectal cancer for Caucasians (OR = 1.14, 95% CI = 1.00-1.30 for ProSer vs. ProPro and OR = 1.16, 95% CI = 1.02-1.31 for Ser carries vs. ProPro).

CONCLUSIONS

This meta-analysis suggested that Ser allele of NQO1 Pro187Ser significantly contributed to the increased risks of colorectal adenoma and cancer in Caucasians.

Role of genetics in the diagnosis and prognosis of Crohn's disease

Considering the epidemiological, genetic and immunological data, we can conclude that the inflammatory bowel diseases are heterogeneous disorders of multifactorial etiology in which hereditability and environment interact to produce the disease. It is probable that patients have a genetic predisposition for the development of the disease coupled with disturbances in immunoregulation. Several genes have so far been related to the diagnosis of Crohn's disease. These genes are related to innate pattern recognition receptors, to epithelial barrier homeostasis and maintenance of epithelial barrier integrity, to autophagy and to lymphocyte differentiation. So far, the strongest and most replicated associations with Crohn's disease have been demonstrated with NOD2, IL23R and ATG16L1 genes. Many genes have so far been implicated in the prognosis of Crohn's disease and many attempts have been made for classification of genetic profiles in Crohn's disease. CARD15 seems to be not only a susceptibility gene, but also a disease-modifier gene for Crohn's disease. Enriching our understanding of Crohn's disease genetics is of value, but when combining genetic data with functional data the outcome could be of major importance to clinicians.

Genes associated with susceptibility to ulcerative colitis

Ulcerative colitis (UC) is a chronic intestinal inflammatory disease whose etiology is still unknown. It is widely believed that UC is a kind of non-specific inflammatory disease which is caused by environmental factors and autoimmune disorders in people who carry susceptibility genes. Epidemiologic data, such as familial aggregation, twin studies, and racial/ethnic differences in disease prevalence, indicate that there are genetic contributions to UC pathogenesis. In this article, we will review the recent progress in research of genes associated with susceptibility to UC.

Association between polymorphism of the tumor necrosis factor alpha-308 gene promoter and colon cancer in the Chinese population

Tumor necrosis factor (TNF) is a type of cytokine that inhibits tumorigenesis. Several studies have assessed the relationship between the polymorphism of TNF-alpha 308G/A and the susceptibility to colon cancer; however, the results have been controversial. A case-control study was carried out to investigate whether TNF-alpha 308G/A gene polymorphism was associated with the risk of colon cancer in a group of 180 cases and 180 controls from Heilongjiang, China. DNA was isolated from peripheral blood, and gene polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism. Results of our study showed that colon cancer cases had a significantly higher frequency of TNF-alpha 308AA genotype (odds ratio=9.42, 95% confidence interval=1.18, 75.15; p=0.03) than controls. When stratified by the tumor location, tumor size, growth pattern, differentiation, and stage of colon cancer, no statistically significant results was observed. The present study demonstrated that TNF-alpha 308AA genotype was associated with a higher risk of colon cancer in the Chinese population. Confirmation of these findings in other populations is required.