Association of TNF-α-308G/A, -238G/A, -863C/A, -1031T/C, -857C/T polymorphisms with periodontitis susceptibility: Evidence from a meta-analysis of 52 studies

The association between tumor necrosis factor-alpha (TNF-α-308G/A, -238G/A, -863C/A, -1031T/C, and -857C/T) polymorphism and either chronic (CP) or aggressive (AgP) periodontitis susceptibility was conflicting. This meta-analysis aimed to quantitatively estimate the association.A total of 52 studies involving 5519 patients and 7260 controls were identified through a search of multiple electronic databases. Odds ratios (ORs) and their 95% confidence intervals using allele, homozygous, heterozygous, dominant, and recessive genetic models were computed to assess the strength of the association.The TNF-α-308G/A polymorphism was significantly associated with decreased risks of CP (GG vs AA: OR = 0.353, P < .001; GG+GA vs AA: OR = 0.480, P < .001) and AgP (G vs A: OR = 0.651, P < .001; GG vs AA: OR = 0.306, P < .001; GG+GA vs AA: OR = 0.384, P < .001) in Asians. There were no associations between TNF-α-238G/A, -863C/A, -1031T/C, -857C/T polymorphism and susceptibility to AgP. No associations were also found between CP susceptibility and TNF-α-238G/A, -857C/T polymorphism.These findings supported that TNF-α-308G/A polymorphism might be the protective factors of CP and AgP in Asians, and TNF-α-238G/A, -863C/A, -1031T/C, -857C/T polymorphism is not linked to AgP susceptibility.

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.

Four tumor necrosis factor alpha genes polymorphisms and periodontitis risk in a Chinese population

BACKGROUND

Tumour necrosis factor-alpha (TNF-alpha) has been implicated in the pathogenesis of generalized aggressive periodontitis (AgP) and chronic periodontitis (CP). The objective of the present study was to evaluate the association of four TNF-alpha gene polymorphisms (-1031T/C, -857C/T, -308G/A and -238G/A) with susceptibility to AgP and CP in a Chinese population.

METHODS

A hospital-based case-control study was conducted in in patients with CP (n = 180), AgP (n = 180) and healthy controls (n = 180). Gene promoter polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Genotype and allele frequencies were analyzed using the chi-square test and logistic regression analysis.

RESULTS

TNF-alpha -1031CC genotype was significantly higher [odds ratio (OR) = 2.36, 95% confidence interval (CI) = 1.03, 5.43; P = 0.04] in patients with CP compared with healthy controls. TNF-alpha -308AA genotype was significantly higher (OR = 2.71, 95% CI = 1.09, 6.73; P = 0.03) in patients with AgP compared with healthy controls. No association was found of TNF-alpha -857C/T and -238G/A polymorphisms with susceptibility to AgP or CP.

CONCLUSIONS

Our data demonstrated that TNF-alpha -1031CC genotype was a risk factor for CP, and that TNF-alpha -308AA genotype was a risk factor for AgP. But there is a lack of association of TNF-alpha -857C/T and -238G/A polymorphisms with susceptibility to AgP or CP in a Chinese population.

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.