Lack of association between a functional polymorphism (rs1800796) in the interleukin-6 gene promoter and lung cancer

Statistical meta-analysis to investigate the association between the Interleukin-6 (IL-6) gene polymorphisms and cancer risk

A good number of genome-wide association studies (GWAS), including meta-analyses, reported that single nucleotide polymorphisms (SNPs) of the IL-6 gene are significantly associated with various types of cancer risks, though some other studies reported insignificant association with cancers, in the literature. These contradictory results may be due to variations in sample sizes and/or deficiency of statistical modeling. Therefore, an attempt is made to provide a more comprehensive understanding of the association between the IL-6 gene SNPs (rs1800795, rs1800796, rs1800797) and different cancer risks, giving the weight on a large sample size, including different cancer types and appropriate statistical modeling with the meta-dataset. In order to attain a more reliable consensus decision about the association between the IL-6 gene polymorphisms and different cancer risks, in this study, we performed a multi-case statistical meta-analysis based on the collected information of 118 GWAS studies comprising of 50053 cases and 65204 control samples. Results from this Meta-analysis indicated a significant association (p-value < 0.05) of the IL-6 gene rs1800796 polymorphism with an overall increased cancer risk. The subgroup analysis data based on cancer types exhibited significant association (p-value < 0.05) of the rs1800795 polymorphism with an overall increased risk of cervical, liver and prostate cancers; the rs1800796 polymorphism with lung, prostate and stomach cancers; and the rs1800797 polymorphism with cervical cancer. The subgroup analysis of ethnicity data showed a significant association (p-value < 0.05) of an overall cancer risk with the rs1800795 polymorphism for the African and Asian populations, the rs1800796 polymorphism for the Asian only and the rs1800797 polymorphism in the African population. Comparative discussion showed that our multi-case meta-analyses received more support than any previously reported individual meta-analysis about the association between the IL-6 gene polymorphisms and cancer risks. Results from this study, more confidently showed that the IL-6 gene SNPs (rs1800795, rs1800796 and rs1800797) in humans are associated with increased cancer risks. Therefore, these three polymorphisms of the IL-6 gene have the potential to be evaluated as a population based rapid, low-cost PCR prognostic biomarkers for different types of cancers diagnosis and research.

Association of VEGFA, TIMP-3, and IL-6 gene polymorphisms with predisposition to optic neuritis and optic neuritis with multiple sclerosis

BACKGROUND

The etiology of the inflammatory ON is multifactorial. Much attention is paid to the inflammatory and immune processes that are likely to contribute to the demyelination and MS development. IL-6, VEGFA, and TIMP-3 genes are thought to be involved in the inflammatory processes and manifestation of CNS demyelination, so we aimed to determine the relationship between VEGFA rs1413711, TIMP-3 rs9621532, IL-6 rs1800796 gene polymorphisms and ON, and ON with MS.

MATERIALS AND METHODS

Patients with ON, ON with MS, and a random sample of healthy population were enrolled. The genotyping of VEGFA rs1413711, TIMP-3 rs9621532, and IL-6 rs1800796 polymorphisms was carried out using the real-time polymerase chain reaction method.

RESULTS

T/C and C/C genotypes of VEGFA rs1413711 were associated with about threefold increased odds of developing ON in the dominant and codominant models. Each allele C at VEGFA rs1413711 was associated with 1.7-fold increased odds of ON development. IL-6 rs1800796 allele C was more frequent in the ON with MS group compared to the control: 17.6% vs. 7.5%, respectively (p = .040). No statistically significant associations were found between TIMP-3 rs9621532 and the ON development.

CONCLUSION: VEGFA

rs1413711 is associated with the ON development.

Polymorphisms of the Highly Expressed IL-6 Gene in the Papillary Thyroid Cancer Susceptibility Among Chinese

BACKGROUND

Papillary thyroid cancer (PTC) is the cardinal histologic type of thyroid cancer, which is the most prevalent kind of endocrine malignancy. The expression of IL-6 is found higher in thyroid carcinoma (THCA) samples than paired normal tissues based on The Cancer Genome Atlas (TCGA) and Genotype-Tissue expression (GTEx) database. In this study, we aimed to investigate the association between interleukin-6 (IL-6) polymorphisms and the PTC risk.

METHODS

A case-control study was designed using the following data: 241 PTC patients and 463 healthy controls. Five single nucleotide polymorphisms (SNPs) in IL-6 were selected and genotyped using Agena MassARRAY technology.

RESULTS

Our results revealed that SNP rs1800796 was associated with an increased PTC risk in co-dominant model (p = 0.042) and dominant model (p = 0.027). Rs1524107 was also a risk factor for PTC susceptibility in co-dominant model (p = 0.003), dominant model (p = 0.002) and log-additive model (p = 0.044). Moreover, rs2066992 significantly increased the PTC risk in co-dominant model and dominant model (p = 0.011, p = 0.009, respectively). Additionally, rs2069837 variant elevated the PTC risk based on dominant model (p = 0.041). In silico analysis, GTEx results for rs1800796, rs1524107 and rs2066992 variants are known to be associated with IL-6 gene expression. Using HaploReg, we found rs1800796, rs1524107 and rs2066992 in LD with functional importance.

CONCLUSION

Our study indicates that IL-6 variants may be a risk factor involved in the pathogenesis and development of PTC.

Association study of genetic variations of inflammatory biomarkers with susceptibility and severity of obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) increases health risks of cardiovascular disease and stroke. Both genetic factors and environmental exposures contribute to the occurrence of OSA. The purpose of this study was to determine the role of four functional inflammatory single nucleotide polymorphisms (SNPs) (VWF rs1063856, IL-6 rs1800796, TNF rs1800629, and CRP rs2794521) in the susceptibility and severity of OSA.

METHODS

A case-control study of OSA among Chinese population was conducted. Genotyping was performed using ABI TaqMan SNP genotyping technique.

RESULTS

We found VWF rs1063856 (OR = 1.50, 95% CIs = 1.10-2.04; p = 0.010), IL-6 rs1800796 (OR = 1.32, 95% CIs = 1.11-1.56; p = 0.002), TNF rs1800629 (OR = 1.44, 95% CIs = 1.13-1.83; p = 0.003), and CRP rs2794521 (OR = 1.27, 95% CIs = 1.04-1.55; p = 0.021) were all significantly associated with increased susceptibility of OSA, while VWF rs1063856 (OR = 1.75, 95% CIs = 1.18-2.62; p = 0.006), IL-6 rs1800796 (OR = 1.39, 95% CIs = 1.10-1.76; p = 0.006) were associated with the severity of OSA.

CONCLUSIONS

Our study indicated that functional variants of inflammatory biomarkers could cause the occurrence of OSA and influence the severity of OSA. These findings further support that inflammatory cytokines were closely related to the occurrence and development of OSA.

Genetic Relationship Between IL-6 rs1800796 Polymorphism and Susceptibility to Periodontitis

BACKGROUND

There are accumulating reports for the potential role of Interleukin-6 (IL-6) rs1800796 polymorphism in the risk of periodontitis. However, distinct conclusions are observed. In this study, we have an interest in comprehensively analyzing the genetic relationship between IL-6 rs1800796 and the susceptibility to periodontitis.

METHODS

We retrieved the eligible case-control studies from on-line database and conducted a meta-analysis. P-value of association test, OR (odd ratios) and 95% CI (confidence interval) were calculated for the assessment of potential genetic association.

RESULTS

We enrolled a total of 20 case-control studies for pooling analysis. A positive association between periodontitis cases and controls was observed in the overall meta-analysis under all genetic models (all P < 0.05, OR > 1). Similar results were detected in the "population-based, PB" and "China" subgroups (all P < 0.05, OR > 1). In the "Asian" subgroup, there is an increased periodontitis risk under the allele, homozygote, heterozygote, dominant and carrier models (all P < 0.05, OR > 1). Nevertheless, negative results were found in the "Caucasian" subgroup under all models [all P > 0.05]. In addition, a positive association between IL-6 rs1800796 and the risk of chronic periodontitis was detected under the models of allele [G vs. C], GG vs. CC, GG vs. CC+ CG and carrier [G vs. C] (all P < 0.05, OR > 1).

CONCLUSION

IL-6 rs1800796 may serve as one genetic risk factor for periodontitis patients in the Asian population, especially the Chinese population. G/G genotype of IL-6 rs1800796 appears to be associated with an increased risk of chronic periodontitis.

Associations between polymorphisms of interleukin-6 and related cytokine genes and serum liver damage markers: a cross-sectional study in the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study

Cytokines, including interleukin-6 (IL-6), play an important role in the liver. The aim of this study was to investigate associations between common polymorphisms in potential functional promoters of cytokine genes and liver damage markers among enrollees of a large Japanese cohort study. Subjects included 3257 Japanese individuals (1608 men and 1649 women, aged 35-69 years). Six single nucleotide polymorphisms (SNPs) in the promoter regions of five cytokine genes, IL1B (T-31C), IL6 (C-634G), IL8 (T-251A), IL10 (T-819C), tumor necrosis factor-A (TNFA) (T-1031C), and TNFA (C-857T), were genotyped by polymerase chain reaction. Information regarding alcohol intake, smoking habits, height, and weight was collected by a self-administered questionnaire. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured during a routine health check-up. Of the six SNPs genotyped, an IL6 polymorphism (rs1800796, C-634G) was most strongly associated with a liver damage marker, AST. Mean serum AST was significantly different among the three genotypes (mean ± SD, 22.7 ± 7.3 IU/L for CC, 22.8 ± 7.7 IU/L for CG, and 24.3 ± 8.6 IU/L for GG, p=0.011 by analysis of variance). The differences remained significant after adjustment for potential confounders by general linear models. The variations in mean serum AST and ALT levels were marked especially among men. Thus, the functional polymorphism IL6 C-634G may affect serum AST and ALT levels, possibly through different IL-6 production.

Association between Catechol-O-methyltransferase rs4680 (G>A) polymorphism and lung cancer risk

Background

The association between the Val158Met polymorphism in the catechol-O-methyltransferase (COMT) gene and lung cancer risk remains controversial and inconclusive. Therefore, the meta-analysis was performed to provide a quality reevaluation of the association between the COMT Val158Met polymorphism and the risk of lung cancer.

Methods

Two major public databases (Pubmed and Embase) and several Chinese databases were searched for eligible studies. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated to estimate the strength of the association.

Results

Five publications, including six individual studies with a total of 4,043 subjects (1,796 cases and 2,247 controls) regarding the association of COMT Val158Met polymorphism with lung cancer susceptibility were included in this meta-analysis. Overall, pooled analysis indicated that there was no significant association between COMT Val158Met polymorphism and lung cancer susceptibility under all genetic models. Likewise, no association was observed in the stratified analysis by ethnicity and control source, either. However, Val158Met polymorphism was shown to increase lung cancer risk among women (AG vs. GG, OR = 1.190, 95% CI = 1.001–1.422, p = 0.049).

Conclusion

These findings suggested that the COMT l58Val/Met polymorphism confer genetic susceptibility to lung cancer among women. However, no evidence was found for the association with lung cancer risk in ethnicity and smoking status.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_192