Positive association between Interleukin-8 -251A > T polymorphism and susceptibility to gastric carcinogenesis: a meta-analysis

Expression of immune regulatory factors, chemokines and growth factors in differentiated gastric cancer cells treated with an anticancer bioactive peptide combined with oxaliplatin

Gastric cancer is one of the most common malignant tumors of the digestive system. An anticancer bioactive peptide (ACBP) was previously shown to have an important role in inhibiting the differentiation of the MKN-45, N87 and GES-1 cell lines. However, to date, research on the effects of inflammatory factors in MKN-45, N87 and GES-1 cell lines after treatment with ACBP combined with oxaliplatin (OXA) has not been performed. To investigate the expression of immune regulatory factors, tumor growth factors and chemotactic factors in differentiated gastric cancer cells treated with ACBP combined with OXA, the expression of cytokines, including interleukin (IL)-1β, IL-1 receptor antagonist, IL-2, IL-4, IL-6-10, IL-12, IL-13, IL-15, IL-17, Eotaxin, basic fibroblast growth factor (bFGF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon (IFN)-γ, monocyte chemoattractant protein (MCP)-1, IFN-γ-induced protein-10, macrophage inflammatory protein (MIP)-1α, platelet-derived growth factor (PDGF)-BB, MIP-1β, regulated upon activation, normal T cell expressed and presumably secreted, TNF-α and VEGF, was assessed with cell experiments using the Bio-Plex ProT Human Cytokine 27-plex Assay. The results indicated that immune regulatory factor, tumor growth factor and chemotactic factor expression levels were different after treatment with ACBP alone or ACBP combined with OXA. IFN-γ, IL-1β, IL-17, IL-9, IL-10, IL-15, bFGF, GM-CSF and PDGF-BB expression was decreased in MKN-45 and N87 cells after ACBP treatment (P<0.01) and ACBP+OXA treatment (P<0.01) compared with the control cells, which indicated that ACBP inhibited tumor growth by regulating these cytokines, and the combination treatment inhibited tumor growth by regulating these cytokines. MIP-1β, MCP-1 and IL-13 expression was decreased in MKN-45 and N87 cells after the combination treatment compared with ACBP treatment alone, which indicated that ACBP combined with OXA was able to inhibit tumor growth by regulating these cytokines, while the mechanism of action of the ACBP and OXA is actually different, e.g. for OXA, this would be to cause DNA damage response. Therefore, the ACBP and OXA combination treatment may be closely associated with tumor progression and metastasis with immunological competence by MCP-1, MIP-1β and IL-13 expression.

Immune response to Helicobacter pylori infection and gastric cancer development

Gastric adenocarcinoma is a global health concern, and Helicobacter pylori (H. pylori) infection is the main risk factor for its occurrence. Of note, the immune response against the pathogen seems to be a determining factor for gastric oncogenesis, and increasing evidence have emphasized several host and bacterium factors that probably influence in this setting. The development of an inflammatory process against H. pylori involves a wide range of mechanisms such as the activation of pattern recognition receptors and intracellular pathways resulting in the production of proinflammatory cytokines by gastric epithelial cells. This process culminates in the establishment of distinct immune response profiles that result from the cytokine-induced differentiation of T naïve cells into specific T helper cells. Cytokines released from each type of T helper cell orchestrate the immune system and interfere in the development of gastric cancer in idiosyncratic ways. Moreover, variants in genes such as single nucleotide polymorphisms have been associated with variable predispositions for the occurrence of gastric malignancy because they influence both the intensity of gene expression and the affinity of the resultant molecule with its receptor. In addition, various repercussions related to some H. pylori virulence factors seem to substantially influence the host immune response against the infection, and many of them have been associated with gastric tumorigenesis.

Contribution of Genetic Polymorphisms of Inflammation Response Genes on Sporadic Colorectal Cancer Predisposition Risk in Malaysian Patients - A Case Control Study

AIM:

To investigate the frequencies and association of polymorphic genotypes of IL-8 -251 T>A, TNF-α -308 G>A, ICAM-1 K469E, ICAM-1 R241G, IL-6 -174 G>C, and PPAR-γ 34 C>G in modulating susceptibility risk in Malaysian colorectal cancer (CRC) patients.

Methods:

In this case-control study, peripheral blood samples of 560 study subjects (280 CRC patients and 280 controls) were collected, DNA extracted and genotyped using PCR-RFLP and Allele Specific PCR. The association between polymorphic genotype and CRC susceptibility risk was determined using Logistic Regression analysis deriving Odds ratio (OR) and 95% CI.

Results:

On comparing the frequencies of genotypes of all single nucleotide polymorphisms ( SNPs ) in patients and controls, the homozygous variant genotypes IL-8 -251 AA and TNF-α -308 AA and variant A alleles were significantly higher in CRC patients. Investigation on the association of the variant alleles and genotypes singly, with susceptibility risk showed the homozygous variant A alleles and genotypes IL-8 -251 AA and TNF-α -308 AA to be at higher risk for CRC predisposition. Analysis based on age, gender and smoking habits showed that the polymorphisms IL8 -251 T>A and TNF – α 308 G>A contribute to a significantly higher risk among male and female who are more than 50 years and for smokers in this population.

Conclusion:

We observed an association between variant allele and genotypes of IL-8-251 T>A and TNF-α-308 G>A polymorphisms and CRC susceptibility risk in Malaysian patients. These two SNPs in inflammatory response genes which undoubtedly contribute to individual risks to CRC susceptibility may be considered as potential genetic predisposition factors for CRC in Malaysian population.

Expression Rate and PAX5 Gene Methylation in the Blood of People Suffering from Gastric Cancer

BACKGROUND:

Gastric cancer is one of the most important health issues in the world. Considering the lack of plenty of pre-awarenesses, the survival of gastric cancer is still quite disappointing. Methylation of PAX5 gene promoter is observed in most cancer cells of a human. A study has shown that PAX5 is a new tumoral suppressor in gastric cancer and methylation of the PAX5 promoter is associated with the survival rate of gastric cancer.

AIM:

The present research seeks to study the expression rate and methylation of the PAX5 gene in the blood of patients who have gastric cancer to be used as a biomarker in this type of cancer.

MATERIAL AND METHODS:

Real-time PCR technique was used to assess expression of PAX5 gene, while the methylation status of PAX5 gene promoter in the blood samples of people who have gastric cancer versus blood samples obtained from normal Iranian population was studied using MS PCR technique.

RESULTS:

The final results pointed to the fact that expression of PAX5 in blood samples obtained from those who have gastric cancer is much less than what is observed in normal blood samples. A significant correlation was also observed between expression of this gene and age and promoter methylation rate. The results of methylation also indicated that 28% of PAX5 gene promoters among patients were methylated, while all normal samples were non-methylated.

CONCLUSION:

Studying the decrease observed in PAX5 gene expression and the rise in promoter methylation can be utilised as a biomarker to enhance pre-awareness of gastric cancer.

Association of IL-8 gene promoter -251 A/T and IL-18 gene promoter -137 G/C polymorphisms with head and neck cancer risk: a comprehensive meta-analysis

Purpose

No consensus exists on the impact of polymorphisms in cytokines (such as interleukin IL-8 and IL-18) on cancer risk; moreover, there is very little evidence regarding head and neck cancer (HNC).

Methods

Thus, a meta-analysis including 22 studies with 4731 cases and 8736 controls was conducted to evaluate this association. The summary odds ratio (OR) and corresponding 95% confidence intervals (CIs) for C-X-C motif chemokine ligand 8 (CXCL8, which encodes IL-8) and IL-18 polymorphisms and HNC risk were estimated.

Results

The results showed a significantly increased risk of HNC susceptibility for IL18 −137 G/C in five genetic models, but, interestingly, no significant association was found for the CXCL8 −251 A/T polymorphism. When stratified by cancer type, an increased risk of nasopharyngeal cancer was found for both −137 G/C and −251A/T. When the studies were stratified by ethnicity and genotyping method, there were significant associations between Asian populations and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) studies for −137 G/C, and African populations for −251 A/T in some genetic models. A positive association was also found between the population-based groups in some models for −137 G/C; conversely, significantly decreased risk was found among the −251 A/T hospital-based group. Meta-regression was also conducted. The publication year, control source, and cancer type contributed to CXCL8 −251 A/T heterogeneity; however, no factors were found that contributed to IL-18 −137 G/C heterogeneity. Marginal significance was found in the recessive model for IL-18 −137 G/C by Egger’s test, whereas no publication bias was detected for CXCL8 −251 A/T.

Conclusions

The results indicate that the IL-18 −137 G/C polymorphism is associated with HNC risk, especially nasopharyngeal cancer, in Asian populations and, when using PCR-RFLP, CXCL8 −251 A/T polymorphisms play a complex role in HNC development.

Comprehensive analysis of interleukin-8 gene polymorphisms and periodontitis susceptibility

Background

Associations between interleukin-8 (IL-8) gene polymorphisms and periodontitis susceptibility have been investigated in many published studies, but the conclusions are still inconsistent. Therefore, we performed this systematic review and meta-analysis to review which polymorphisms have been researched and to obtain a precise result of the same polymorphism from different studies.

Results

Finally 10 publications involving 1938 patients and 1569 controls were yielded, including 12 polymorphisms. Six studies investigated rs4073 polymorphism; two focused on rs2227306 and rs2227307; two referred to rs2227532 and T-738A; one detected rs2230054, rs1126579 and rs1126580; one inspected A2767T, T₁1722T₂ and C1633T, and one for rs2234671 polymorphism. Of them, IL-8 C1633T and rs1126580 polymorphisms showed positive association while the other ten polymorphisms revealed negative results.

Materials and methods

A comprehensive literature search from PubMed, Web of Science, and Chinese National Knowledge Infrastructure was conducted for all potentially relevant studies published before January 2, 2017. Two authors selected the studies and extracted data. The pooled analysis was conducted using the RevMan 5.1 software if a polymorphism was reported by two or more studies.

Conclusions

Based on current evidence, the IL-8 rs4073, A2767T, T₁1722T₂, rs2234671, rs2230054, rs1126579, rs2227306, rs2227307, rs2227532, and T-738A polymorphisms were not associated with periodontitis susceptibility; the IL-8 C1633T and rs1126580 polymorphisms were associated with increased risk of periodontitis.

Interleukin-6 Genetic Variation and Susceptibility to Gastric Cancer in an Iranian Population

Background:

Despite recent decrease in the incidence of gastric cancer, it is still a common type of cancer in the north of Iran. Many evaluations have shown that polymorphisms of cytokine genes like that for interleukin 6 (IL-6), which play important roles in regulation of the immune response, can increase the risk of gastric cancer. This study examined the role of the IL-6-174 gene polymorphism in susceptibility in an Iranian population.

Method:

Genomic DNA was extracted from peripheral whole blood of 100 patients and 361 healthy controls. Genotyping was accomplished by the sequence-specific primer-polymerase chain reaction (SSP-PCR) method and statistical analyses were carried out using Fisher’s exact test. Frequencies of the IL-6-174 G/C genotypes were determined under co-dominant, dominant, and recessive genetic models.

Results:

An association between the polymorphism of IL-6 -174 G/C and susceptibility to gastric cancer was observed. The frequency of G allele was higher in patients (78%) than in controls (70.5 %) (OR=1.48, 95% CI=1.01-2.20, P=0.04).

Conclusions:

The high G allele and G/G genotype frequency in patients compared to control subjects suggests that the IL-6 -174 G/C polymorphism may influence the susceptibility to gastric cancer. In addition, the demographic information showed that most of the subjects were male (69.0%) that gastric cancer is related to environmental factors.

Predicting the functional consequences of non-synonymous single nucleotide polymorphisms in IL8 gene

Here we report an in-silico approach for identification, characterization and validation of deleterious non-synonymous SNPs (nsSNPs) in the interleukin-8 gene using three steps. In first step, sequence homology-based genetic analysis of a set of 50 coding SNPs associated with 41 rsIDs using SIFT (Sorting Intolerant from Tolerant) and PROVEAN (Protein Variation Effect Analyzer) identified 23 nsSNPs to be putatively damaging/deleterious in at least one of the two tools used. Subsequently, structure-homology based PolyPhen-2 (Polymorphism Phenotyping) analysis predicted 9 of 23 nsSNPs (K4T, E31A, E31K, S41Y, I55N, P59L, P59S, L70P and V88D) to be damaging. According to the conditional hypothesis for the study, only nsSNPs that score damaging/deleterious prediction in both sequence and structural homology-based approach will be considered as 'high-confidence' nsSNPs. In step 2, based on conservation of amino acid residues, stability analysis, structural superimposition, RSMD and docking analysis, the possible structural-functional relationship was ascertained for high-confidence nsSNPs. Finally, in a separate analysis (step 3), the IL-8 deregulation has also appeared to be an important prognostic marker for detection of patients with gastric and lung cancer. This study, for the first time, provided in-depth insights on the effects of amino acid substitutions on IL-8 protein structure, function and disease association.

Interaction between Helicobacter pylori and host genetic variants in gastric carcinogenesis

Helicobacter pylori (H. pylori) is the definite carcinogen of gastric cancer. H. pylori infection induces chronic inflammation, causes DNA damage and aberrant methylation of genes and these pathways are involved in H. pylori-related gastric carcinogenesis. Polymorphisms of the genes involved in these pathways could alter susceptibility to gastric cancer. In this mini review, we focused on the role of polymorphisms in these genes on the susceptibility to gastric cancer, with a particular emphasis on their possible interactions with H. pylori infection. We found that many studies on this theme did not simultaneously report H. pylori infection and the interactions remained inconclusive.

Association between Interleukin-8-251A/T polymorphism and gastric cancer susceptibility: a meta-analysis based on 5286 cases and 8000 controls

OBJECTIVES

Published data on the association between Interleukin-8-251A/T polymorphism and gastric cancer (GC) risk are inconclusive. Thus, we conducted a meta-analysis to evaluate the relationship between cyclin D1 G870A polymorphism and GC risk.

METHODS

We searched PubMed, EMBASE, Web of science and the Cochrane Library up to July 12, 2015 for relevant studies. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate the strength of associations.

RESULTS

Twenty-six studies published from 2004 to 2015, with a total of 5286 cases and 8000 controls, were included in this meta-analysis. The pooled results showed that there was significant association between Interleukin-8-251A/T polymorphism and GC risk in any genetic model. In the subgroup analysis by ethnicity, the effects remained in Asians. However, no genetic models reached statistical association in Europeans. The subgroup analysis stratified by Source of controls showed an increased breast cancer risk in hospital-based (HB) studies in any genetic model except recessive model. However, there was no association in any genetic model in population based (PB) studies. When stratifying by Genotyping method, we found statistical association in Non-RFLP (restriction fragment length polymorphism) in any genetic model except heterozygote comparison, the effect was remain in PCR-RFLP in dominant model and heterozygote comparison.

CONCLUSIONS

This meta-analysis suggests that Interleukin-8-251A/T polymorphism is a risk factor for susceptibility to GC in overall population, especially in Asians, in hospital populations and in Non-RFLP. While, there was no association in Europeans and in general population. Further large scale multicenter epidemiological studies are warranted to confirm this finding.

Genetics and gastric cancer susceptibility

Gastric cancer has high morbidity and mortality in China. It is ranked first in malignant tumors of the digestive system. Its etiology and pathogenesis are still unclear, but they may be associated with a variety of factors. Genetic susceptibility genes have become a research hotspot in China. Elucidating the genetic mechanisms of gastric cancer can facilitate achieving individualized prevention and developing more effective methods to reduce clinical adverse consequences, which has important clinical significance. Genetic susceptibility results from the influence of genetic factors or specific genetic defects that endow an individual's offspring with certain physiological and metabolic features that are prone to certain diseases. Currently, studies on the genetic susceptibility genes of gastric cancer have become a hotspot. The purpose is to screen for the etiology of gastric cancer, search for gene therapy methods, and ultimately provide a scientific basis for the prevention and control of gastric cancer. This article reviews the current progress of studies on genetic susceptibility genes for gastric cancer.

Interleukin-8 -251A/T gene polymorphism and lung cancer susceptibility: a meta-analysis

Many studies have examined the association between the interleukin-8 -251T/A (rs4073) gene polymorphism and lung cancer risk in various populations, but the results have been inconsistent. In this meta-analysis, PubMed was searched for case-control studies published through 01 December 2013. The data were extracted, and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. We assessed six published studies on the association between the interleukin-8 -251T/A polymorphism and lung cancer risk. The included studies yielded a total of 3265 lung cancer cases and 3607 controls. For the homozygous A/A and A allele carriers (T/A + A/A), the pooled ORs for all studies combining 3265 cases and 3607 controls were 1.03 (95% CI = 0.92-1.14; P = 0.235 for heterogeneity) and 1.07 (95% CI = 0.96-1.19; P = 0.245 for heterogeneity) when compared with the homozygous wild-type genotype (T/T). When the analysis was stratified by ethnicity, significant risks were found among Asians for both the A allele carriers and the homozygous A/A individuals. However, no significant associations were found in non-Asian populations using any of the genetic models. This meta-analysis suggests that the interleukin-8 -251A allele confer an increased risk for the development of lung cancer among Asians.

Human viruses and cancer

The first human tumor virus was discovered in the middle of the last century by Anthony Epstein, Bert Achong and Yvonne Barr in African pediatric patients with Burkitt's lymphoma. To date, seven viruses -EBV, KSHV, high-risk HPV, MCPV, HBV, HCV and HTLV1- have been consistently linked to different types of human cancer, and infections are estimated to account for up to 20% of all cancer cases worldwide. Viral oncogenic mechanisms generally include: generation of genomic instability, increase in the rate of cell proliferation, resistance to apoptosis, alterations in DNA repair mechanisms and cell polarity changes, which often coexist with evasion mechanisms of the antiviral immune response. Viral agents also indirectly contribute to the development of cancer mainly through immunosuppression or chronic inflammation, but also through chronic antigenic stimulation. There is also evidence that viruses can modulate the malignant properties of an established tumor. In the present work, causation criteria for viruses and cancer will be described, as well as the viral agents that comply with these criteria in human tumors, their epidemiological and biological characteristics, the molecular mechanisms by which they induce cellular transformation and their associated cancers.

Association between interleukin-8 -251A/T polymorphism and risk of lung cancer: a meta-analysis

This study is to evaluate the association between IL-8 -251A/T polymorphism and lung cancer risk in diverse populations. We performed a meta-analysis of six case-control studies that included 3,265 lung-cancer cases and 3,607 case-free controls. Overall, results showed that the IL-8 -251A/T polymorphism was not associated with a significantly increased risk of lung cancer in all genetic models. However, stratified by ethnicity, a significantly increased risk was found among Asians. In conclusion, IL-8 -251A/T polymorphism is associated with lung cancer susceptibility in Asians and the -251 A allele may increase risk of lung cancer in Asians.

E-selectin S128R polymorphism is associated with cancer risk: a meta-analysis

BACKGROUND

Genetic factors have been shown to play an important role in the development of cancers. However, individual studies may fail to completely demonstrate complicated genetic relationships because of small sample size. Therefore, we performed a meta-analysis to evaluate the association of E-selectin Ser128Arg (S128R) with cancer risk.

MATERIALS AND METHODS

A literature search in PubMed, Embase, Web of Science, Science Direct, SpringerLink, EBSCO, Wanfang, and Chinese National Knowledge Infrastructure databases was carried out to identify studies of the association between E-selectin S128R polymorphism and cancer risk. The odds ratio (OR) with 95% confidence intervals (95%CIs) were used to assess the strength of association.

RESULTS

A total of eight studies involving 1,675 cancer cases and 2,285 controls were included in the meta-analysis. In overall populations, S128R polymorphism seemed to be associated with cancer risk (Arg allele vs Ser allele: OR=1.65, 95%CI =1.33-2.04, p<0.01; Arg/Arg+Arg/Ser vs Ser/Ser: OR=1.87, 95%CI =1.48-2.36, p<0.01; Arg/Ser vs Ser/Ser: OR=1.80, 95%CI =1.51-2.14, p<0.01). Similarly, subgroup analysis by ethnicity and source of control also revealed that this polymorphism was related to cancer risk.

CONCLUSIONS

Our meta-analysis revealed that there was association between the E-selectin S128R polymorphism and the risk of cancer. Further large and well-designed studies are needed to confirm this association.

Role of gene polymorphisms in gastric cancer and its precursor lesions: Current knowledge and perspectives in Latin American countries

Latin America shows one of the highest incidence rates of gastric cancer in the world, with variations in mortality rates among nations or even within countries belonging to this region. Gastric cancer is the result of a multifactorial complex process, for which a multistep model of carcinogenesis is currently accepted. Additionally to the infection with Helicobacter pylori, that plays a major role, environmental factors as well as genetic susceptibility factors are significant players at different stages in the gastric cancer process. The differences in population origin, demographic structure, socio-economic development, and the impact of globalization lifestyles experienced in Latin America in the last decades, all together offer opportunities for studying in this context the influence of genetic polymorphisms in the susceptibility to gastric cancer. The aim of this article is to discuss current trends on gastric cancer in Latin American countries and to review the available published information about studies of association of gene polymorphisms involved in gastric cancer susceptibility from this region of the world. A total of 40 genes or genomic regions and 69 genetic variants, 58% representing markers involved in inflammatory response, have been used in a number of studies in which predominates a low number of individuals (cases and controls) included. Polymorphisms of IL-1B (-511 C/T, 14 studies; -31 T/C, 10 studies) and IL-1RN (variable number of tandem repeats, 17 studies) are the most represented ones in the reviewed studies. Other genetic variants recently evaluated in large meta-analyses and associated with gastric cancer risk were also analyzed in a few studies [e.g., prostate stem cell antigen (PSCA), CDH1, Survivin]. Further and better analysis centered in gene polymorphisms linked to other covariates, epidemiological studies and the information provided by meta-analyses and genome-wide association studies should help to improve our understanding of gastric cancer etiology in order to develop appropriate health programs in Latin America.

The polymorphism interleukin-8 -251A/T is associated with a significantly increased risk of cancers from a meta-analysis

Emerging evidences show that interleukin-8 (IL-8) has important regulatory functions in tumorigenesis. IL-8 -251A/T is a single nucleotide polymorphism in the promoter region of the IL-8 gene and affects IL-8 production. Analysis of previous studies on the association of -251A/T polymorphism with different cancer types remained to be illustrated. To further assess the effect of -251A/T polymorphism on cancer risks, we performed this meta-analysis, up to November 2013, of 12,917 cases with different cancer types and 17,689 controls from 47 published case-control designed studies. Statistical analyses were performed using STATA 11.0 software. Crude odds ratios (ORs) with 95 % confidence intervals (CIs) were used to assess the strength of associations. ORs with 95 % CIs for IL-8 -251A/T polymorphism and cancer were estimated using fixed- and random-effects models when appropriate. Significantly increased risks were found in overall under the models of A allele vs. T allele, AA vs. TT, and AA vs. AT/TT. Significantly elevated risks were observed in breast cancer under the models of A allele vs. T allele, AT vs. TT, AA/AT vs. TT, and AA vs. AT/TT, and in nasopharyngeal carcinoma under the models of AT vs. TT, AA/AT vs. TT, and AA vs. AT/TT. We found that significantly elevated risks were observed in the Asian population and hospital-based studies in all comparison models. Thus, this meta-analysis indicates that IL-8 -251A/T polymorphism is associated with a significantly increased risk of cancers and may provide evidence-based medical certificate to study the cancer susceptibility.