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

Research Note: Xylooligosaccharide directly attenuates Salmonella Typhimurium colonization and its induction of impairments in intestinal barrier and growth performance of broilers

Xylooligosaccharide (XOS) is known as a prebiotic, however, it is unknown whether XOS can directly protect against bacterial infection. This study aimed to investigate the direct inhibitory effects of XOS on Salmonella Typhimurium colonization and the inductive impairments in gut health and growth performance in broilers. We first probed the inhibitory effects of XOS on S. Typhimurium adhesion and its induction of intestinal epithelial cell (IPEC-J2) injuries. Afterward, 168 one-day-old yellow-feathered broilers were randomly divided into 3 groups (7 replicates/group): negative control (NC, received a basal diet), positive control (PC, received a basal diet with S. Typhimurium challenge) and XOS group (PC birds + 1,500 mg/kg XOS). All birds except those in NC were orally challenged with S. Typhimurium from 8 to 10 d of age. Parameters were analyzed on d 11. The results showed that XOS inhibited S. Typhimurium adhesion and the inductive injuries of IPEC-J2 cells by lowering (P < 0.05) certain adhesion-related genes expression of this bacterium. It also alleviated S. Typhimurium-induced increase (P < 0.05) in the expression of certain inflammatory cytokines and tight junction (TJ) proteins of IPEC-J2 cells. Supplementing XOS to S. Typhimurium-challenged broilers attenuated the elevations (P < 0.05) in S. Typhimurium colonization of ileal mucosa and its translocation to the liver and spleen, as well as increased (P < 0.05) certain TJ proteins expression of ileum. Besides, XOS addition normalized S. Typhimurium-induced impairments (P < 0.05) in ileal morphology, final body weight and average daily gain in broilers. Collectively, supplemental XOS directly suppressed intestinal colonization of S. Typhimurium by diminishing its adhesiveness and subsequently mitigated destructions in intestinal barriers, thus contributing to weaken growth retardation in challenged broilers. Our findings provide a new insight into the mechanisms of XOS limiting Salmonella infection in chickens.

Association of Polymorphisms in Cytokine genes with susceptibility to Precancerous Lesions and Cervical Cancer: A systematic review with meta-analysis

Objectives: This study investigated the relationship between single-nucleotide polymorphisms (SNPs) in cytokine genes and the susceptibility to Squamous Intraepithelial Lesions (SIL), cervical cancer and HPV infection through a systematic review with meta-analysis. To verify the effect of SNPs, we also analyzed the transcription factor binding affinity using bioinformatics tools.Methods: Seven electronic databases (MEDLINE, Scielo, BIREME, PubMed, Scopus, Web of Science and Science Direct) were searched for case-control studies.Results: A total of 35 relevant case-control studies were meta-analyzed, including 7 cytokine genes and 15 SNPs. SNPs in IL-17A (rs2275913, rs3748067); IL-17 F (rs763780); IL-12A (rs568408); IL-12B (rs3212227); TNFA (rs1800629, rs361525); IL-1B (rs16944); IL-6 (rs1800795); IL-10 (rs1800896) genes were associated with increased risk for cervical cancer. No association was observed between meta-analyzed polymorphisms and SIL. Additional bioinformatics analysis suggested a possible transcriptional regulation pathway of the TNFA and IL-10 genes through the MZF1 (TNFA -308 G > A and IL-10 - 1082A>G) and ZNF263 (TNFA -238 G > A) transcription factors binding.Conclusion: Overall, 10 SNPs in cytokine genes were associated with increased risk for cervical cancer. Therefore, in our meta-analysis, these SNPs demonstrated to be potential biomarkers for predicting or identifying cases of high risk for SIL and cervical cancer.

Genetic susceptibility in cervical cancer: From bench to bedside

Cervical cancer (CC) is the third most common malignancy in women globally, and persistent infection with the oncogenic human papillomaviruses (HPV) is recognized as the major risk factor. The pathogenesis of CC relies on the interplay between the tumorigenic properties of the HPV and host factors. Host-related genetic factors, including the presence of susceptibility loci for cervix tumor is substantial importance. Preclinical and genome-wide association studies (GWAS) have reported the associations of genetic variations in several susceptibility loci for the development of cervical cancer. However, many of these reports are inconsistent. In this review, we discuss the findings to date of candidate gene association studies, and GWAS in cervical cancer. The associations between these genetic variations with response to chemotherapy are also discussed.

Tumor necrosis factor-α (TNF-α)-308G/A promoter polymorphism in colorectal cancer in ethnic Kashmiri population - A case control study in a detailed perspective

Background

Inflammation constitutes one of the important components of colorectal cancer (CRC) pathogenesis. Tumor necrosis factor-α (TNF-α), a cytokine and an important inflammatory mediator plays a pivotal role in the malignant cellular proliferation, angiogenesis, tissue invasion and metastasis in CRC. The studies on association of various polymorphisms in human TNF-α gene including TNF-α-308G/A single nucleotide polymorphism (SNP) are limited, mixed and inconclusive.

Materials and methods

The aim of this study was to analyze the association of TNF-α-308G/A promoter SNP with colorectal cancer (CRC) susceptibility and development risk and also to evaluate the modifying effects of possible TNF-α-308G/A genotypes on different risk factors of CRC in ethnic population of Kashmir, India through a case–control setup. The genotype frequencies of TNF-α-308G/A promoter SNP were compared between 142 CRC patients and 184 individually matched healthy controls by using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method. The associations between the TNF-α-308G/A SNP and CRC risk were examined through conditional logistic regression models adjusted for multiple possible confounding (third) variables. Further, the associations between this SNP and various clinico-pathological parameters, demographic variables and environmental factors within the case group subjects with regard to CRC risk were also evaluated.

Results

The association between the TNF-α-308G/A SNP and the modulation of risk of CRC was not found to be significant (p value = 0.156). The effect of less common TNF-α-308A allele on the risk of colorectal cancer was also not found to be significant (p value = 0.175). The variant genotype (AA) was nonexistent in the study population. Further, we found no significant effect modulation of CRC risk by wild and heterozygous TNF-α-308G/A SNP genotypes in presence of different possible risk factors (p > 0.05). We also found no significant association of TNF-α-308G/A SNP with the subsets of various characteristics of the case group subjects under study (p > 0.05).

Conclusions

This study indicates that there is no significant association between the TNF-α-308G/A promoter SNP and the risk of developing CRC in ethnic Kashmiri population. However, in order to substantiate our findings, this study needs to be replicated with bigger sample size and should involve other ethnically defined populations with high CRC risk.

Risk allelic load in Th2 and Th3 cytokines genes as biomarker of susceptibility to HPV-16 positive cervical cancer: a case control study

Background

Alterations in the host cellular immune response allow persistent infections with High-Risk Human Papillomavirus (HR-HPV) and development of premalignant cervical lesions and cervical cancer (CC). Variations of immunosuppressive cytokine levels in cervix are associated with the natural history of CC. To assess the potential role of genetic host immunity and cytokines serum levels in the risk of developing CC, we conducted a case–control study paired by age.

Methods

Peripheral blood samples from patients with CC (n = 200) and hospital controls (n = 200), were used to evaluate nine biallelic SNPs of six cytokine genes of the adaptive immune system by allelic discrimination and cytokines serum levels by ELISA.

Results

After analyzing the SNP association by multivariate logistic regression adjusted by age, CC history and smoking history, three Th2 cytokines (IL-4, IL-6 and IL-10) and one Th3 (TGFB1) cytokine were significantly associated with CC. Individuals with at least one copy of the following risk alleles: T of SNP (−590C > T IL-4), C of SNP (−573G > C IL-6), A of SNP (−592C > A IL-10), T of SNP (−819C > T IL-10) and T of SNP (−509C > T TGFB1), had an adjusted odds ratio (OR) of 2.08 (95 % CI 1.475–2.934, p = 0.0001), an OR of 1.70 (95 % CI 1.208–2.404, p = 0.002), an OR of 1.87 (95 % CI 1.332–2.630, p = 0.0001), an OR of 1.67 (95 % CI 1.192–2.353, p = 0.003) and an OR of 1.91 (95 % CI 1.354–2.701, p = 0.0001), respectively, for CC. The burden of carrying two or more of these risk alleles was found to have an additive effect on the risk of CC (p trend = 0.0001). Finally, the serum levels of Th2 and Th3 cytokines were higher in CC cases than the controls; whereas IFNG levels, a Th1 cytokine, were higher in controls than CC cases.

Conclusion

The significant associations of five SNPs with CC indicate that these polymorphisms are potential candidates for predicting the risk of development of CC, representing a risk allelic load for CC and can be used as a biomarker of susceptibility to this disease.

Association of single nucleotide polymorphisms in tumor necrosis factor-alpha with cervical cancer susceptibility

Tumor necrosis factor-alpha (TNF-α) polymorphisms have been reported to play an important role in the development of cervical cancer. But the results remain inconclusive. We performed this study to provide a comprehensive assessment of the association by means of a meta-analysis in which all published studies were included. The studies investigating the associations between cervical cancer risk and TNF-α polymorphisms were identified through PubMed, Embase, CNKI, and Chinese BioMedical Literature Database. OR and 95% CI (odds ratio and 95% confidence interval) were calculated using either the fixed or random effects model to assess the associations. We eventually included eighteen case-control studies of SNP -308 G>A and nine studies of SNP -238 G>A. Meta-analysis of the former polymorphism suggested significantly increased risk of cervical cancer associated with the A allele (OR 1.19, 95% CI 1.02-1.38). Subgroup analysis according to ethnicity showed similar results in Caucasians (A vs. G: OR 1.25, 95% CI 1.02-1.54; AA vs. GG: OR 1.47, 95% CI 1.04-2.08; AA vs. GA+GG: OR 1.47, 95% CI 1.04-2.08). For SNP -238 G>A, a protective association was observed in overall comparisons (A vs. G: OR 0.64, 95% CI 0.51-0.80; AA+GA vs. GG: OR 0.62, 95% CI 0.49-0.79) and subgroup analysis of Caucasians (A vs. G: OR 0.67, 95% CI 0.53-0.83; AA+GA vs. GG: OR 0.65, 95% CI 0.51-0.82). Our meta-analysis indicates that TNF-α polymorphisms may confer susceptibility to cervical cancer in an ethic-specific fashion.

TNF-α -308 G/A as a risk marker of cervical cancer progression in the Polish population

BACKGROUND AND OBJECTIVE

There are inconclusive data on the tumor necrosis factor-α (TNF-α) -308 G/A (rs1800629) polymorphism as a risk factor for cervical carcinogenesis.

METHODS

Using high-resolution melting curve analysis, we investigated the prevalence of the TNF-α -308 G/A transition (rs1800629) in patients with cervical cancer (n = 362) and control subjects (n = 399).

RESULTS

The p trend value calculated for the TNF-α -308 G/A transition was statistically significant (p trend = 0.026) for all patients. Logistic regression analysis with adjustment for age demonstrated that the A/A versus G/G genotype was significantly associated with cervical tumors. The adjusted odds ratio (OR) was 1.599 (95 % confidence interval [CI] 1.017-2.513; p = 0.042). Stratification of patients on the basis of the tumor stage revealed no contribution of the TNF-α -308 G/A transition to cervical cancer in stages I and II. However, we found a significant trend for the p value, as well as the contribution of TNF-α -308 G/A to cervical cancer, in stages III and IV. The p trend value was 0.003 in this group of patients. Moreover, logistic regression analysis with adjustment for age demonstrated that the adjusted OR for A/A versus G/G was 2.014 (95 % CI 1.122-3.613; p = 0.019) and the adjusted OR for A/A or A/G versus G/G was 1.583 (95 % CI 1.025-2.444; p = 0.038) for cervical cancer in stages III and IV.

CONCLUSION

Our results indicate that the TNF-α -308 G/A transition is a risk factor for cervical cancer, particularly in stages III and IV.

The association between tumor necrosis factor-α-308 G/A polymorphism and risk for vitiligo: a meta-analysis

BACKGROUND

The contribution of tumor necrosis factor-α (TNF-α)-308 G/A gene polymorphism (rs1800629) to risk for vitiligo is subject to controversy.

OBJECTIVES

The fundamental purpose of the present meta-analysis was to investigate large-scale evidence to determine the overall association between TNF-α-308 G/A polymorphism and susceptibility to vitiligo.

METHODS

A literature search of the PubMed, EMBASE, Web of Science, and China National Knowledge Infrastructure (CNKI) databases was conducted to identify all studies referring to an association between TNF-α-308 G/A polymorphism and vitiligo published to June 1, 2014. The principal outcome measure for evaluating the strength of the association was the crude odds ratio (OR) along with the corresponding 95% confidence interval (CI). Data were extracted, and statistical analyses were implemented using stata Version 12.0.

RESULTS

Data for a total of 1505 vitiligo cases and 2253 controls from five case-control studies concentrating on the association between TNF-α-308 G/A polymorphism and vitiligo were included in this meta-analysis. Combined analysis revealed there to be no association between this polymorphism and susceptibility to vitiligo in five genetic models under random-effects models. A subgroup analysis by clinical type also demonstrated the absence of any association between TNF-α-308 G/A polymorphism and generalized vitiligo. However, a significant association was detected in the miscellaneous subgroup under the dominant model (fixed-effects model: OR 5.69, 95% CI 4.70-6.88; P = 0.000) and overdominant model (random-effects model: OR 5.24, 95% CI 2.26-12.17; P = 0.000).

CONCLUSIONS

This meta-analysis indicates that TNF-α-308 G/A polymorphism is not a genetic risk factor for vitiligo.

Stratification analysis and case-control study of relationships between interleukin-6 gene polymorphisms and cervical cancer risk in a Chinese population

Interleukin-6 (IL-6), a central proinflammatory cytokine, maintains immune homeostasis and also plays important roles in cervical cancer. Therefore, we aimed to evaluate any associations of IL-6 gene polymorphisms at positions -174 and -572 with predisposition to cervical cancer in a Chinese population. The present hospital- based case-control study comprised 518 patients with cervical cancer and 518 healthy controls. Polymorphisms of the IL-6 gene were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Patients with cervical cancer had a significantly higher frequency of the IL-6 -174 CC genotype [odds ratio (OR) =1.52, 95% confidence interval (CI) = 1.06-2.19; p=0.02], IL-6 -572 CC genotype (OR =1.91, 95% CI = 1.16-3.13; p=0.01) and IL-6 -174 C allele (OR =1.21, 95% CI = 1.02-1.44; p=0.03) compared to healthy controls. When stratifying by the FIGO stage, patients with III-IV cervical cancer had a significantly higher frequency of IL-6 -174 CC genotype (OR =1.64, 95% CI =1.04-2.61; p=0.04). The CC genotypes of the IL-6 gene polymorphisms at positions -174 and -572 may confer a high risk of cervical cancer. Additional studies with detailed human papillomavirus (HPV) infection data are warranted to validate our findings.

Tumor necrosis factor, tumor necrosis factor inhibition, and cancer risk

OBJECTIVE

Tumor necrosis factor (TNF) is a highly pleiotropic cytokine with multiple activities other than its originally discovered role of tumor necrosis in rodents. TNF is now understood to play a contextual role in driving either tumor elimination or promotion. Using both animal and human data, this review examines the role of TNF in cancer development and the effect of TNF and TNF inhibitors (TNFis) on malignancy risk.

RESEARCH DESIGN

A literature review was performed using relevant search terms for TNF and malignancy.

RESULTS

Although administration of TNF can cause tumor regression in specific rodent tumor models, human expression polymorphisms suggest that TNF can be a tumor-promoting cytokine, whereas blocking the TNF pathway in a variety of tumor models inhibits tumor growth. In addition to direct effects of TNF on tumors, TNF can variously affect immunity and the tumor microenvironment. Whereas TNF can promote immune surveillance designed to eliminate tumors, it can also drive chronic inflammation, autoimmunity, angiogenesis, and other processes that promote tumor initiation, growth, and spread. Key players in TNF signaling that shape this response include NF-κB and JNK, and malignant-inflammatory cell interactions, each of which may have different responses to TNF signaling. Focusing on rheumatoid arthritis (RA) patients, where clinical experience is most extensive, a review of the clinical literature shows no increased risk of overall malignancy or solid tumors such as breast and lung cancers with exposure to TNFis. Lymphoma rates are not increased with use of TNFis. Conflicting data exist regarding the risks of melanoma and nonmelanoma skin cancer. Data regarding the risk of recurrent malignancy are limited.

CONCLUSIONS

Overall, the available data indicate that elevated TNF is a risk factor for cancer, whereas its inhibition in RA patients is not generally associated with an increased cancer risk. In particular, TNF inhibition is not associated with cancers linked to immune suppression. A better understanding of the tumor microenvironment, molecular events underlying specific tumors, and epidemiologic studies of malignancies within specific disease indications should enable more focused pharmacovigilance studies and a better understanding of the potential risks of TNFis.

The association between the polymorphisms of TNF-α and non-Hodgkin lymphoma: a meta-analysis

Many genetic variations in the promoter region of tumor necrosis factor alpha (TNF-α) may confer host susceptibility to cancer by influencing TNF-α expression. Nevertheless, the results remain inconclusive. The current meta-analysis was performed to investigate the association between three common TNF-α promoter polymorphisms and the risk of non-Hodgkin lymphoma (NHL). A literature search was conducted mainly from PubMed for all eligible studies. The pooled odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were used to assess the association of TNF-α polymorphisms with the risk of NHL. TNF-α -308 A allele showed a statistically significant increased risk for NHL under the homozygous (AA vs. GG, OR = 1.51, 95 % CI = 1.26-1.80) and recessive (OR = 1.47, 95 % CI = 1.23-1.75) models, respectively. The stratified analyses showed an increased risk of NHL with the presence of TNF-α -308 A allele among Africans and Caucasians, but a decreased risk among Asians. No association was observed between -238 G/A polymorphism and NHL risk either in the overall analysis or in the stratified analysis. Similarly, pooled analysis did not reveal an altered risk of NHL with -857 C/T polymorphism. Nonetheless, a statistically significant association was observed among Asians when stratified by ethnicity. Among the three genetic variations of interest, TNF-α -308 G/A polymorphism was significantly associated with the risk of NHL; neither -238 G/A nor -857 C/T polymorphism was shown to alter the overall NHL risk; however, stratified analysis by ethnicity observed a statistically significant association between -857 C/T polymorphism and the risk of NHL among Asians.

Lessons and implications from association studies and post-GWAS analyses of cervical cancer

Cervical cancer has a heritable genetic component. A large number of genetic associations with cervical cancer have been reported in hypothesis-driven candidate gene studies, but many of these results are either inconsistent or have failed to be independently replicated. Genome-wide association studies (GWAS) have identified additional susceptibility loci previously not implicated in cervical cancer development, highlighting the power of genome-wide unbiased association analyses. Post-GWAS analyses including pathway-based analysis and functional characterization of associated variants have provided new insights into the pathogenesis of cervical cancer. In this review we summarize findings from candidate gene association studies, GWAS, and post-GWAS analyses of cervical cancer. We also discuss gaps in our understanding, possible clinical implications of the findings, and lessons for studies of other complex diseases.

Dynamics of proinflammatory cytokine levels and their role in the development of local and systemic effects during progressing cervical cancer

In order to evaluate the role of cytokines in the development of polymodal local and distant effects in patients with stages I-IV cervical cancer, the following parameters were measured: serum concentrations of TNF-α, IFN-γ, IL-1β, IL-6, and IL-10; levels of malondialdehyde, activities of catalase, superoxide dismutase, glutathione reductase, and glutathione-S-reductase in the plasma, erythrocyte, and cervix uteri homogenate. The expression of p53, Bcl-2, VEGF, and Ki-67 in tumor tissue was evaluated. High levels of malondialdehyde in tumor tissue and erythrocyte were paralleled by low levels of superoxide dismutase and catalase and high activities of glutathiones. Medium correlations between Ki-67, Bcl-2, and p53 and the levels of IL-6, IL-10, and TNF-α at stages Ib-IIa were detected. The results indicated that the progress of cervical cancer was associated with the neoplasm integration in the host homeostasis by using the regional and systemic cytokine functions. These effects, amplifying the biological potential of the tumor, were the most significant at stages Ib-IIa.

Tumor Necrosis Factor Alpha (-238 / -308) and TNFRII-VNTR (-322) Polymorphisms as Genetic Biomarkers of Susceptibility to Develop Cervical Cancer Among Tunisians

Host genetic factors may confer susceptibility to Cervical Cancer. TNF-α as pro-inflammatory cytokine participates in the maintenance of immune homeostasis. Allelic variation of immuno-modulatory genes is associated with alteration in immune function. This study investigated the associations between TNF-α-308G>A, -238G>A, and TNFRII - VNTR-322 and cervical cancer in Tunisian women. Genotypes of those polymorphisms were detected in 130 cases and 260 controls. The variant heterozygote -308 G/A was associated with a 41% decreased risk of cervical cancer (GG vs A/A; p = 0.002; OR = 0.41; 95% CI =0.23-0.76). Furthermore, compared with dominant variant G/G, the (G/A+A/A) genotypes was significantly associated with a decreased risk of CC (GG vs G/A+A/A; p = 0.026; OR = 0.62; 95% CI = 0.40-0.97). The FIGO stratified analysis showed that the minor variant A/A and combined G/A+A/A of TNFα-238 G>A and TNFα-308 G>A increased the risk of the tumor evolution, respectively, (P = 0.011; OR = 2.98; 95% CI = 1.16-7.72) (P = 0.008; OR = 2.76; 95% CI = 1.20-6.41), (P = 0.000; OR = 16.33; 95% CI = (5.10-55.23) (P = 0.000; OR = 7.54; 95% CI = 2.68-22.29). There was statistically significant relationship between the incidence of the TNF-α mutations and the clinical progression of cancer according to the FIGO classification. In our study, the haploview analysis revealed no LD between rs1800629 and rs361525. TNF-α and TNFRII polymorphisms might be genetic risk factors for cervical cancer in Tunisian population.

Effect of cytotoxic T-lymphocyte antigen-4, TNF-alpha polymorphisms on osteosarcoma: evidences from a meta-analysis

OBJECTIVE

Previous studies have investigated the role of cytotoxic T-lymphocyte antigen-4 (CTLA-4) and tumor necrosis factor-alpha (TNF-α) in carcinogenesis of osteosarcoma, but their results were inconsistent. We aimed to clarify the associations between CTLA-4, TNF-α polymorphism and osteosarcoma risk by using meta-analysis.

METHODS

We searched relevant studies without language restriction in PubMed, EMbase, Cochrane Library, Google Scholar databases, Chinese National Knowledge Infrastructure (CNKI) and conference literature in humans published prior to March 2013. The strengths of the associations between genetic variants and osteosarcoma risk were estimated by odds ratio (OR) with 95% confidence interval (95% CI).

RESULTS

A total of seven studies with 1,198 osteosarcoma patients and 1,493 controls were selected. Four studies were eligible for CTLA-4 (1,003 osteosarcoma and 1,162 controls), and three studies for TNF-α (195 osteosarcoma and 331 controls). Pooled results showed that rs231775 polymorphism of CTLA-4 was associated with osteosarcoma risk (GG vs. AA: OR=1.63, 95% CI=1.24-2.13; GG + GA vs. AA: OR=1.56, 95% CI=1.21-2.01; AA + GA vs. GG: OR=0.83, 95% CI=0.71-0.97; G vs. A: OR=1.21, 95% CI=1.08-1.36). No significant heterogeneity was observed across the studies. No significant associations were found between rs5742909 polymorphism of CTLA-4 or rs1800629 polymorphism of TNF-α and osteosarcoma risk.

CONCLUSIONS

These results suggest that the rs231775 polymorphism of CTLA-4 may play an important role in carcinogenesis of osteosarcoma.

Tumor necrosis factor-a polymorphisms and colorectal cancer risk: a meta-analysis

BACKGROUND AND OBJECTIVES

Tumor necrosis factor-alpha (TNF-a) was related to inflammation and involved in the development of colorectal cancer. Polymorphisms located in TNF-a promoter region, such as 308G/A and 238G/A, could affect the risk of various types of cancer by regulating TNF-a production. In this study, a meta-analysis was performed to investigate the association between common polymorphisms of TNF-a promoter region and colorectal cancer susceptibility.

METHODS

Searching of several databases was performed for all publications on the association between TNF-a polymorphisms and colorectal cancer. Summary odds ratios (ORs) with their 95% confidence intervals (95% CIs) were calculated using random-effects models. Stratified analyses based on ethnicity and control population source were also conducted.

RESULTS

Overall, TNF-a 308A polymorphism showed a significant association with increased risk of colorectal cancer in worldwide populations under homozygote comparison [AA vs. GG, OR (95% CI) = 1.46 (1.07-1.97)] other than heterozygote comparison [AG vs. GG, OR (95% CI) = 1.05 (0.93-1.19)]. TNF-a 238A was not associated with colorectal cancer risk under homozygote or heterozygote comparisons. In stratified analysis, significant association was observed only in Western populations [AA vs. GG, OR (95% CI) = 1.39 (1.01-1.91)] other than in Eastern populations under homozygote comparison. No significant difference was observed between population-based subgroup and hospital-based subgroup.

CONCLUSIONS

TNF-a 308A was moderately associated with an increased risk of colorectal cancer in Western populations, and TNF-a 238A polymorphism was not significantly associated with colorectal cancer risk.

Associations between Fas/FasL polymorphisms and susceptibility to cervical cancer: a meta-analysis

Genetic polymorphisms in the Fas/Fas ligand (FasL) gene were proposed to be associated with susceptibility to cervical cancer, but previous studies reported controversial findings. We performed a meta-analysis to assess the associations between Fas/FasL polymorphisms and susceptibility to cervical cancer. We carried out a literature search in PubMed and Embase databases for studies on the associations between Fas/FasL polymorphisms and susceptibility to cervical cancer. The associations were assessed by odds ratio (OR) together with its 95% confidence intervals (CIs). Eleven individual studies with a total of 6,919 subjects were finally included into the meta-analysis. Overall, there was no association between Fas 1377G > A polymorphism and susceptibility to cervical cancer (A vs. G: OR = 0.99, 95% CI 0.88-1.12, P = 0.91; AA vs. GG: OR = 1.00, 95% CI 0.76-1.32, P = 0.99; AA/GA vs. GG: OR = 0.95, 95% CI 0.81-1.12, P = 0.54; AA vs.

GG/GA

OR = 1.11, 95% CI 0.85-1.43, P = 0.45). In addition, there was also no association between FasL 844 T > C polymorphism and susceptibility to cervical cancer (C vs. T: OR = 1.12, 95% CI 0.91-1.36, P = 0.28; CC vs. TT: OR = 1.17, 95% CI 0.90-1.51, P = 0.24; CC/TC vs. TT: OR = 1.13, 95% CI 0.92-1.39, P = 0.24; CC vs.

TT/TC

OR = 1.11, 95% CI 0.83-1.50, P = 0.47). In subgroup analysis by ethnicity, there were also no associations between Fas/FasL polymorphisms and susceptibility to cervical cancer in Asians and Africans. In conclusion, Fas 1377G > A polymorphism and FasL 844 T > C polymorphism are both not associated with susceptibility to cervical cancer.

CD95 rs1800682 polymorphism and cervical cancer risk: evidence from a meta-analysis

CD95 is the first death receptor identified and characterized in recent years, and it plays important roles in the molecular network regulating cell death and survival. CD95 rs1800682 polymorphism is a common genetic polymorphism identified in the CD95 gene. Many publications evaluated the association between CD95 rs1800682 polymorphism and cervical cancer risk, but the association remained inconclusive. To provide a more precise estimate on the association, a meta-analysis was carried out. The association between CD95 rs1800682 polymorphism and cervical cancer risk was assessed by calculating the pooled odds ratio (OR) with its 95% confidence intervals (95% CI). On the basis of our inclusion criteria, ten studies with a total of 5,481 individuals were included into the meta-analysis. There was obvious heterogeneity among the included studies. Meta-analysis of the ten studies suggested that there was no association between CD95 rs1800682 polymorphism and cervical cancer risk under all four genetic models (allele model: OR = 1.05, 95% CI 0.92-1.18, P = 0.478; homozygous model: OR = 1.08, 95% CI 0.83-1.41, P = 0.550; dominant model: OR = 1.12, 95% CI 0.88-1.42, P = 0.347; recessive model: OR = 1.00, 95% CI 0.76-1.31, P = 0.978). Subgroup analysis by ethnicity suggested that there was no association between CD95 rs1800682 polymorphism and cervical cancer risk in Asians, Caucasians, and Africans. Thus, the meta-analysis suggests that CD95 rs1800682 polymorphism is not associated with cervical cancer risk.

Association between FAS A670G polymorphism and susceptibility to cervical cancer: evidence from a meta-analysis

Previous studies published to evaluate the association between FAS A670G polymorphism and susceptibility to cervical cancer provided conflicting findings. A meta-analysis of published case-control studies was performed to get a comprehensive evidence for the possible association. We searched in PubMed and Wanfang databases for eligible studies published before February 10, 2013. The odds ratio (OR) with 95% confidence interval (95% CI) was used to evaluate the association. Ten studies with a total of 4,904 participants were finally included into the meta-analysis. Overall, there was no obvious association between FAS A670G polymorphism and susceptibility to cervical cancer under all four genetic models (G versus A: OR = 0.97, 95% CI 0.84-1.11, P = 0.64; GG versus AA: OR = 0.92, 95% CI 0.69-1.24, P = 0.60; GG/AG versus AA: OR = 0.99, 95% CI 0.77-1.26, P = 0.92; GG versus AA/AG: OR = 0.92; 95% CI 0.68-1.25, P = 0.59). Subgroup analyses by ethnicity further showed that there was no association between FAS A670G polymorphism and susceptibility to cervical cancer in both Caucasians and Asians. There was no risk of publication bias. In summary, the meta-analysis suggests that there is no association between FAS A670G polymorphism and susceptibility to cervical cancer in both Caucasians and Asians.

Tumor necrosis factor-α 238 G/A polymorphism and gastric cancer risk: a meta-analysis

Though many studies were performed to assess the association between tumor necrosis factor-α (TNF-α) 238 G/A polymorphism and gastric cancer risk, there were no conclusive findings. A meta-analysis of previous published studies was performed to get a comprehensive assessment of the association between TNF-α 238 G/A polymorphisms and gastric cancer. The pooled odds ratios (ORs) and 95% confidence intervals (95 % CIs) were calculated to assess the association. Fifteen studies with a total of 7,795 participants were finally included into this meta-analysis. Overall, there was an obvious association between TNF-α 238 G/A polymorphism and increased risk of gastric cancer (A vs. G: OR = 1.32, 95% CI 1.02-1.72, P = 0.036; GA vs. GG: OR = 1.32, 95% CI 1.01-1.72, P = 0.042; and AA/GA vs. GG: OR = 1.34, 95% CI 1.02-1.76, P = 0.036). Subgroup analysis by ethnicity showed the statistically significant association between TNF-α 238 G/A polymorphism and gastric cancer was limited to Asian populations (A vs. G: OR = 1.59, 95% CI 1.29-1.97, P < 0.001; GA vs. GG: OR = 1.63, 95% CI 1.29-2.04, P < 0.001; and AA/GA vs. GG: OR = 1.64, 95%CI 1.31-2.05, P < 0.001), and there was no obvious association in Caucasians. In conclusion, TNF-α 238 G/A polymorphism is significantly associated with increased risk of gastric cancer, especially in Asians.