Genetic variants in T helper cell type 1, 2 and 3 pathways and gastric cancer risk in a Polish population

Population-enriched innate immune variants may identify candidate gene targets at the intersection of cancer and cardio-metabolic disease

Both cancer and cardio-metabolic disease disparities exist among specific populations in the US. For example, African Americans experience the highest rates of breast and prostate cancer mortality and the highest incidence of obesity. Native and Hispanic Americans experience the highest rates of liver cancer mortality. At the same time, Pacific Islanders have the highest death rate attributed to type 2 diabetes (T2D), and Asian Americans experience the highest incidence of non-alcoholic fatty liver disease (NAFLD) and cancers induced by infectious agents. Notably, the pathologic progression of both cancer and cardio-metabolic diseases involves innate immunity and mechanisms of inflammation. Innate immunity in individuals is established through genetic inheritance and external stimuli to respond to environmental threats and stresses such as pathogen exposure. Further, individual genomes contain characteristic genetic markers associated with one or more geographic ancestries (ethnic groups), including protective innate immune genetic programming optimized for survival in their corresponding ancestral environment(s). This perspective explores evidence related to our working hypothesis that genetic variations in innate immune genes, particularly those that are commonly found but unevenly distributed between populations, are associated with disparities between populations in both cancer and cardio-metabolic diseases. Identifying conventional and unconventional innate immune genes that fit this profile may provide critical insights into the underlying mechanisms that connect these two families of complex diseases and offer novel targets for precision-based treatment of cancer and/or cardio-metabolic disease.

Impact of the cytotoxic T-lymphocyte associated antigen-4 rs231775 A/G polymorphism on cancer risk

Background

Cytotoxic T-lymphocyte associated antigen-4 (CTLA-4) is an immunosuppressive checkpoint that is involved in the development and metastasis of cancers. Several studies revealed that CTLA-4 rs231775A/G polymorphism may be associated with the risk of cancer in some populations, but the conclusions of these studies are not consistent.

Methods

We conducted a pooled analysis with eligible studies to explore the association between the CTLA-4 rs231775 variant and cancer risk. Additionally, we used in silico tools to evaluated the expression of CTLA-4 on urinary system cancer. Moreover, we adopted the enzyme-linked immunosorbent assay (ELISA), and Gene Set Enrichment Analysis (GSEA) to investigate the effects of CTLA-4 on bladder cancer (BLCA).

Results

In total, 92 case-control studies involving 29,987 patients with cancer and 36,484 healthy individuals (controls) were included in the pooled analysis. In the stratified analysis based on cancer type, the rs231775 A/G polymorphism was associated with increased bladder cancer risk in the heterozygote contrast model (OR = 1.23, 95% CI = 1.01-1.51, P = 0.040). The race-stratified analysis revealed that East Asians with the GG genotype had a 12% lower risk of developing cancer than those with the GA + AA genotype (95% CI = 0.81-0.95, P = 0.001). The in silico analysis showed that CTLA-4 expression was augmented in patients with BLCA. The ELISA results revealed that CTLA-4 expression was reduced in patients with BLCA carrying the AA genotype. Several signaling pathways, including cytokine-cytokine receptor interactions and T-cell receptor signaling, were associated with CTLA-4 expression.

Conclusion

The CTLA-4 rs231775 A/G polymorphism is associated with cancer risk in East Asian population. This polymorphism is especially associated with BLCA.

Prognostic significance of the genetic variant of lymphotoxin alpha (p.Thr60Asn) in egyptian patients with advanced hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide in terms of mortality, and susceptibility is attributed to genetic, lifestyle, and environmental factors. Lymphotoxin alpha (LTA) has a crucial role in communicating the lymphocytes with stromal cells and provoking cytotoxic effects on the cancer cells. There are no reports on the contribution of the LTA (c.179 C>A; p.Thr60Asn; rs1041981) gene polymorphism to HCC susceptibility. The main aim of this study is to investigate the association of LTA (c.179 C>A; p.Thr60Asn; rs1041981) variant with the HCC risk in the Egyptian population.

METHODS

This case-control study included 317 participants (111 HCC patients, and 206 healthy controls). The LTA (c.179 C>A; p.Thr60Asn; rs1041981) polymorphism was assessed by tetra-primer amplification refractory mutation system polymerase chain reaction (T-ARMS-PCR) technique.

RESULTS

The frequencies of the dominant and recessive models (CA + AA; AA) of the LTA (c.179 C>A; p.Thr60Asn; rs1041981) variant were statistically significant among HCC patients in comparison to controls (p = 0.01; p = 0.007; respectively). The A-allele of LTA (c.179 C>A; p.Thr60Asn; rs1041981) variant was statistically significant in HCC patients in comparison to controls (p ˂ 0.001).

CONCLUSION

The LTA (c.179 C>A; p.Thr60Asn; rs1041981) polymorphism was independently associated with an increased risk for hepatocellular carcinoma in the Egyptian population.

Genetic Analysis Reveals Different Mechanisms of IL-5 Involved in the Development of CAD in a Chinese Han Population

Background

Coronary artery disease (CAD) is a complex disease and the leading cause of death worldwide. It is caused by genetic and environmental factors or their interactions. Candidate gene association studies are an important genetic strategy for the study of complex diseases, and multiple variants of inflammatory cytokines have been found to be associated with CAD using this method. Interleukin-5 (IL-5) is an important inflammatory immune response factor that plays a role in a various inflammatory disease. Clinical tests and animal experiments indicated that IL-5 is involved in CAD development, but the exact mechanisms are unclear. This study investigated the genetic relationship between the single nucleotide polymorphisms (SNPs) in IL5 and CAD.

Materials and Methods

Based on the Chinese Han population, we collected 1,824 patients with CAD and 1,920 control subjects and performed a two-stage case-control association analysis for three SNPs in IL5 (rs2057687, rs78546665, and rs2069812) using the high resolution melt (HRM) technology. Logistic regression analyses were applied to adjust for traditional risk factors for CAD and to perform haplotype and gene interaction analyses. Multiple linear regression analyses were used to study relationships between the selected SNPs and serum lipid levels.

Results

In this study, two-stage case-control association analysis revealed that the allele and genotype frequency distributions of the three IL5 SNPs were not statistically significant between the case and control groups. In addition, none of the IL5 haplotypes were associated with CAD. Further stratified analyses were conducted by sex, age, hypertension, and disease status, respectively, and the results revealed that the rs2057687 and rs2069812 of IL5 were associated with CAD in the male group (p adj = 0.025, OR, 0.77 (95% CI, 0.62-0.97); p adj = 0.016, OR, 0.82 (95% CI, 0.70-0.97), respectively); the rs2057687 and rs78546665 of IL5 were associated with late-onset CAD (p adj = 0.039, OR, 0.78 (95% CI, 0.62-0.99); p adj = 0.036, OR, 1.46 (95% CI, 1.02-1.53), respectively); the rs2069812 of IL5 was associated with CAD in the hypertension group (p adj = 0.036, OR, 0.84 (95% CI, 0.71-0.99)); and none of the SNPs in IL5 were associated with different CAD states (anatomical CAD and clinical CAD). In addition, the association between SNPs and the serum lipid levels indicated that rs78546665 was positively correlated with triglyceride levels (p = 0.012). Finally, SNP-SNP interaction analyses revealed that interactions of rs2057687 and rs2069812 were associated with CAD (p adj = 0.046, OR, 0.77 (95% CI, 0.13-4.68)).

Conclusion

This study suggested that the common variants of IL5 might play a role in CAD by affecting the risk factors for CAD and through SNP-SNP interactions, which provides a new target for specific treatment of CAD patients and a theoretical basis for personalized medicine.

Th2 Cytokines (Interleukin-5 and -9) Polymorphism Affects the Response to Anti-TNF Treatment in Polish Patients with Ankylosing Spondylitis

Ankylosing spondylitis (AS) is an inflammatory disease that belongs to the spondyloarthritis family. IL-5 and IL-9 belong to the group of Th2 cytokines of anti-inflammatory nature. Polymorphisms in their coding genes have been so far associated with various inflammatory diseases, but there are no reports regarding their involvement in AS pathogenesis to date. The purpose of the study was to investigate relationships between IL5 and IL9 genetic variants with AS susceptibility, clinical parameters as well as response to therapy with TNF inhibitors. In total 170 patients receiving anti-TNF therapy and 218 healthy controls were enrolled in the study. The genotyping of IL5 rs2069812 (A > G) and IL9 rs2069885 (G > A) single nucleotide polymorphisms was performed using the Real-Time PCR method based on LightSNiP kits assays. The present study demonstrated significant relationships between IL5 rs2069812 and IL9 rs2069885 polymorphisms and response to anti-TNF therapy. Presence of the IL5 rs2069812 A allele in patients positively correlated with better response to treatment (p = 0.022). With regard to IL9 rs2069885, patients carrying the A allele displayed better outcomes in anti-TNF therapy (p = 0.046). In addition, IL5 rs2069812 A and IL9 rs2069885 A alleles were associated with lower CRP and VAS values. The obtained results may indicate a significant role for IL-5 and IL-9 in the course of AS and response to anti-TNF therapy.

Comprehensive Analysis of 29,464 Cancer Cases and 35,858 Controls to Investigate the Effect of the Cytotoxic T-Lymphocyte Antigen 4 Gene rs231775 A/G Polymorphism on Cancer Risk

In our previous studies, we found that the rs231775 polymorphism of cytotoxic T-lymphocyte antigen 4 (CTLA-4) is associated with risks of different cancer types; however, the association remains controversial and ambiguous, so we conducted an in-depth meta-analysis to verify the association. A complete search of the PubMed, Google Scholar, Embase, Chinese databases, and Web of Science was conducted without regard to language limitations, covering all publications since November 20, 2021. The search criteria for cancer susceptibility associated with the polymorphism in the CTLA-4 gene rs231775 resulted in 87 case-control studies with 29,464 cases and 35,858 controls. The association strength was analyzed using odds ratios and 95% confidence intervals. Overall, we found that the CTLA-4 rs231775 polymorphism may reduce cancer risk. A stratified cancer type analysis showed that CTLA-4 rs231775 polymorphism was a risk factor for colorectal cancer and thyroid cancer; on the other hand, it was a protective factor for breast cancer, liver cancer, cervical cancer, bone cancer, head and neck, and pancreatic cancer. We also classified cancer into five systems and observed an increased association with digestive tract cancer, decreased associations with orthopedic tumors, tumors of the urinary system, and gynecological tumors. In the subgroup based on race, decreased relationships were observed in both Asians and Caucasians. The same decreased association was also shown in the analysis of the source of control analysis. Our present study indicates that the CTLA-4 rs231775 polymorphism contributes to cancer development and aggression.

The role of Serum Interleukin-4 and Interleukin-6 in Helicobacter pylori-infected patients

BACKGROUND

Helicobacter pylori (H. pylori) is a Gram-negative bacteria that colonizes the gastrointestinal mucosa and causes chronic inflammation.

AIMS

There are several studies related to cytokines concentrations in H. pylori infection, but there is no study that clarifies the role of IL-4 and IL-6 together in H. pylori infection.

SUBJECTS

and methods: A total of (65) individuals, (25) healthy controls and (40) patients with H. pylori infection which are submitted to the hepato-gastrointestinal unit of AL-Imamian Al-Kadhimiyain medical hospital city in Baghdad consulted and diagnosed by traditional ways. In addition, the diagnosis was confirmed by ELISA Helicobacter pylori IgG kit. IL-4 and IL-6 levels were also assessed by using ELISA kits, according to the manufactures procedures.

RESULTS

Significant increase of IL-4 and IL-6 concentration in seropositive patients compared with seronegative controls.

CONCLUSION

Our findings and previous researches indicate that the immune response of gastric mucosa to H. pylori varies among patients. It depends on the stage of infection, and increases the cytokines secretion in the chronic stage, which is expected because of increased immune cell infiltration at the site of infection.

Immune Checkpoint Molecules-Inherited Variations as Markers for Cancer Risk

In recent years, immunotherapy has been revolutionized by a new approach that works by blocking receptors called immune checkpoints (IC). These molecules play a key role in maintaining immune homeostasis, mainly by suppressing the immune response and by preventing its overactivation. Since inhibition of the immune response by IC can be used by cancer to avoid recognition and destruction by immune system, blocking them enhances the anti-tumor response. This therapeutic approach has brought spectacular clinical effects. The ICs present heterogeneous expression patterns on immune cells, which may affect the effectiveness of immunotherapy. The inherited genetic variants in regulatory regions of ICs genes can be considered as potential factors responsible for observed inter-individual differences in ICs expression levels on immune cells. Additionally, polymorphism located in exons may introduce changes to ICs amino acid sequences with potential impact on functional properties of these molecules. Since genetic variants may affect both expression and structure of ICs, they are considered as risk factors of cancer development. Inherited genetic markers such as SNPs may also be useful in stratification patients into groups which will benefit from particular immunotherapy. In this review, we have comprehensively summarized the current understanding of the relationship between inherited variations of CTLA-4, PDCD1, PD-L1, BTLA, TIM-3, and LAG-3 genes in order to select SNPs which can be used as predictive biomarkers in personalized evaluation of cancer risk development and outcomes as well as possible response to immunotherapy.

The effect of LTA gene polymorphisms on cancer risk: an updated systematic review and meta- analysis

Purpose: To provide a comprehensive account of the association of five Lymphotoxin-α (LTA) gene polymorphisms (rs1041981, rs2229094, rs2239704, rs746868, rs909253) with susceptibility to cancer.

Methods: A literature search for eligible candidate gene studies published before 28 February 2020 was conducted in the PubMed, Medline, Google Scholar and Web of Science. The following combinations of main keywords were used: (LTA OR Lymphotoxin alpha OR TNF-β OR tumor necrosis factor-beta) AND (polymorphism OR mutation OR variation OR SNP OR genotype) AND (cancer OR tumor OR neoplasm OR malignancy OR carcinoma OR adenocarcinoma). Potential sources of heterogeneity were sought out via subgroup and sensitivity analysis, and publication bias were estimated.

Results: Overall, a total of 24 articles with 24577 cases and 33351 controls for five polymorphisms of LTA gene were enrolled. We identified that rs2239704 was associated with a reduced risk of cancer. While for other polymorphisms, the results showed no significant association with cancer risk. In the stratified analysis of rs1041981, we found that Asians might have less susceptibility to cancer. At the same time, we found that rs2239704 was negatively correlated with non-Hodgkin lymphoma (NHL). While, for rs909253, an increased risk of cancer for Caucasians and HCC susceptibility were uncovered in the stratified analysis of by ethnicity and cancer type.

Conclusion:LTA rs2239704 polymorphism is inversely associated with the risk of cancer. LTA rs1041981 polymorphism is negatively associated with cancer risk in Asia. While, LTA rs909253 polymorphism is a risk factor for HCC in Caucasian population.

Contrasting serum biomarker profiles in two Colombian populations with different risks for progression of premalignant gastric lesions during chronic Helicobacter pylori infection

BACKGROUND

Colombians in coastal Tumaco have a lower incidence of Helicobacter pylori-associated gastric cancer compared to individuals from Tuquerres in the high Andes. This is despite nearly universal prevalence of H. pylori infection and chronic gastritis.

METHODS

H. pylori infection was confirmed by Steiner stain and serology using African and European-origin strains. Gastric histology and serum inflammatory biomarkers in dyspeptic Tumaco or Tuquerres patients were evaluated to predict progression of gastric lesions.

RESULTS

H. pylori infection was nearly universal by Steiner stain and serology. IgG response to European-origin H. pylori strains were greater than African-origin. High gastric cancer-risk Tuquerres patients, compared to low-risk Tumaco, had significant odds ratios for lesion progression associated with serum IL-5, trefoil factor 3 (TFF3), and low pepsinogen I/II ratio. Sensitivity and specificity for these parameters was 63.8% and 67.9%, respectively, with correctly classifying patients at 66.7%. Most odds ratios for 26 other biomarkers were significant for the town of residency, indicating an environmental impact on Tumaco patients associated with decreased lesion progression.

CONCLUSION

An IL-5 association with progression of gastric lesions is novel and could be evaluated in addition to TFF3 and pepsinogen I/II ratio as a non-invasive prognostic screen. Results suggest Tumaco patients were exposed to infectious diseases beyond H. pylori such as the documented high incidence of helminthiasis and toxoplasmosis.

IMPACT

Results support a prior recommendation to evaluate TFF3 and pepsinogen I/II together to predict aggressive gastric histology. Our data indicate IL-5 should be further evaluated as prognostic parameter.

TGFβ C-509T, TGFβ T869C, XRCC1 Arg194Trp, IKBα C642T, IL4 C-590T Genetic polymorphisms combined with socio-economic, lifestyle, diet factors and gastric cancer risk: A case control study in South Indian population

BACKGROUND

Gastric cancer is worldwide the third major cause of cancer related death. Risk factors for gastric cancer includes Helicobacter pylori infection, gastric ulcer, less hygienic condition, use of tobacco, alcohol consumption, use of salted, smoked food, genetic alterations etc. In order to identify the risk factors associated with gastric cancer in South Indian population a case-control study involving 200 proven gastric cancer cases and 400 controls was conducted.

METHODS

A structured questionnaire was used to interview all the subjects who participated in our study. Genotyping assay was performed using Taqman allelic discrimination assay for 5 Single Nucleotide Polymorphisms (SNPs)-TGFβ C-509T, TGFβ T869C, XRCC1 Arg194Trp, IkBα C642T and IL4C-590T.

RESULTS

Odds Ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression. Statistical analysis on socio-economic factors, lifestyle factors had showed that subjects from low socio economic status, use of tobacco and consumption of non-vegetarian food had increased risk of developing gastric cancer. Multi-factorial analysis for the SNPs adjusting for the risk factors obtained in this study showed that TGFΒ C-509T TT genotypes had four fold increased risk of gastric cancer (OR = 4.11, CI = 1.02-16.56) and TGFβ T869C CC genotype had a decreased risk of gastric cancer (OR = 0.21, CI = 0.05-0.85).

CONCLUSION

Economic status, tobacco use and food habits play a significant role in gastric cancer development. TT genotype for TGFβ C-509T had an increased risk and CC genotype for TGFβ T869C had a decreased risk of gastric cancer in south Indian population after adjusting for socio-economic factors and lifestyle factors.

Local Immune Response in Helicobacter pylori Infection

There have been few studies concerning the cytokine profiles in gastric mucosa of Helicobacter pylori-infected patients with normal mucosa, chronic gastritis, and gastric carcinoma (GAC).In the present study, we aimed to elucidate the genomic expression levels and immune pathological roles of cytokines-interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-4, IL-6, IL-10, transforming growth factor (TGF)-β, IL-17A, IL-32-in H pylori-infected patients with normal gastric mucosa (NGM; control), chronic active gastritis (CAG), and GAC. Genomic expression levels of these cytokines were assayed by real-time PCR analysis in gastric biopsy specimens obtained from 93 patients.We found that the genomic expression levels of IFN-γ, TNF-α, IL-6, IL-10, IL-17A mRNA were increased in the CAG group and those of TNF-α, IL-6, IL-10, IL-17A, TGF-β mRNA were increased in the GAC group with reference to H pylori-infected NGM group.This study is on the interest of cytokine profiles in gastric mucosa among individuals with normal, gastritis, or GAC. Our findings suggest that the immune response of gastric mucosa to infection of H pylori differs from patient to patient. For individual therapy, levels of genomic expression of IL-6 or other cytokines may be tracked in patients.

Current evidence on the cytotoxic T-lymphocyte antigen 4 + 49G > A polymorphism and digestive system cancer risks: a meta-analysis involving 11,923 subjects

Cytotoxic T-lymphocyte antigen (CTLA-4) plays an important role in downregulating T cell activation and proliferation. The CTLA-4 + 49G > A polymorphism is one of the most commonly studied polymorphisms in this gene due to its association with many cancer types, but the association between CTLA-4 + 49G > A polymorphism and digestive system cancer risks remain inconclusive. An updated meta-analysis based on 17 independent case-control studies consisting of 5176 cancer patients and 6747 controls was performed to address this association. Overall, there was no statistically increased risk of digestive system cancers in every genetic comparison. In subgroup analysis, this polymorphism was significantly linked to higher risks for pancreatic cancer (GG vs. AA, OR = 1.976, 95% CI = 1.496-2.611; GA vs. AA, OR = 1.433, 95% CI = 1.093-1.879; GG/GA vs. AA, OR = 1.668, 95% CI = 1.286-2.164; GG vs. GA/AA, OR = 1.502, 95% CI = 1.098-2.054; G vs. A, OR = 1.394, 95% CI = 1.098-1.770). We also observed increased susceptibility of hepatocellular cell carcinoma in homozygote comparison (OR = 1.433, 95% CI = 1.100-1.866) and dominant model (OR = 1.360, 95% CI = 1.059-1.746). According to the source of controls, significant effects were only observed in hospital-based studies (GA/AA vs. GG, OR = 1.257, 95% CI = 1.129-1.399). In the stratified analysis by ethnicity, no significantly increased risks were found in either Asian or Caucasian. Our findings suggest that the CTLA-4 + 49G > A polymorphism may be associated with the risk of pancreatic cancer and hepatocellular cell carcinoma.

Little association between the interleukin 10-3575T/A polymorphism and cancer risk: pooled analysis of 15608 cancer cases and 17539 controls

The aim of the present work was to evaluate the association between the interleukin 10 (IL-10) -3575T/A (rs1800890) polymorphism and cancer risk. We performed a met-analysis based on 15 studies, including 15608 cancer cases and 17539 controls. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association, and performed sensitivity analyses. In the stratified analyses by all included studies, no association between IL-10-3575T/A (rs1800890) polymorphism and cancer risk (OR=0.966, 95% CI=0.889-1.05, P=0.417 for A vs. T; OR=1.035, 95% CI=0.975-1.1, P=0.257 for AA vs. AT+TT; OR=1.008, 95% CI=0.964-1.054, P=0.723 for AA+AT vs. TT) was observed. In the stratified analyses by cancer type of lymphoma and non-lymphoma, no association between them was also detected (Lymphoma: OR=1.021, 95% CI=0.962-1.083, P=0.496 for A vs. T; OR=1.029, 95% CI=0.967-1.095, P=0.363 for AA vs. AT+TT; OR=1.017, 95% CI=0.952-1.086, P=0.626 for AA+AT vs. TT; Non-lymphoma: OR=0.966 95% CI=0.889-1.51, P=0.245 for A vs. T; OR=1.035, 95% CI=0.975-1.1, P=0.287 for AA vs. AT+TT; OR=1.017, 95% CI=0.948-1.091, P=0.967 for AA+AT vs. TT). The results were the same by sensitivity analyses. No publication bias was existed in the analysis. The interleukin 10-3575T/A polymorphism may have no association with cancer risk.

A meta-analysis of association between cytotoxic T lymphocyte associated antigen-4 polymorphisms and gastric cancer risk

AIM: To investigate the correlation between cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) gene polymorphisms and gastric cancer risk.

METHODS: Two reviewers independently searched PubMed, FMRS, CNKI, VIP and WanFang Data from January 1, 1990 to May 1, 2014 for case-control studies on the correlation between CTLA-4 gene polymorphisms and gastric cancer risk. According to inclusion and exclusion criteria, two reviewers independently screened the literature, extracted the data, and assessed the methodological quality. A meta-analysis was then performed using RevMan 5.2 software.

RESULTS: A total of 10 case-control studies concerning the CTLA-4 +49 A/G, CTLA-4 -1661A/G, CTLA-4 -1722T/C and CTLA-4 -318 T/C polymorphisms were included in the meta-analysis. The CTLA-4 +49 and CTLA-4 -318 alleles were not associated with genetic susceptibility to gastric cancer. The CTLA-4 -1661 A/G polymorphism was significantly associated with an increased gastric cancer risk (AG vs AA: OR = 2.04, 95%CI: 1.60-2.61, P < 0.00001; AG/GG vs AA: OR = 1.79, 95%CI: 1.43-2.25, P < 0.00001). The CTLA-4 -1722T/C polymorphism was also significantly associated with an increased gastric cancer risk (TT vs CC, OR = 1.66, 95%CI: 1.05-2.62, P = 0.03; TC vs CC, OR = 2.11, 95%CI: 1.05-4.24, P = 0.04; TT/TC vs CC, OR = 1.84, 95%CI: 1.20-2.82, P = 0.04).

CONCLUSION: The CTLA-4 +49 and CTLA-4 -318 alleles are not associated with genetic susceptibility to gastric cancer. The CTLA-4 -1661A/G and -1772T/C polymorphisms are associated with an increased risk of gastric cancer. CTLA-4 -1661 AG and GG allele carrying individuals may have increased incidence of gastric cancer. CTLA-4 -1772 allele carrying TT and TC may increase the incidence of gastric cancer in individuals.

A Polymorphism in the IL-5 Gene is Associated with Inhibitor Development in Severe Hemophilia A Patients

OBJECTIVE

A severe complication in the replacement therapy of hemophilia A (HA) patients is the development of alloantibodies (inhibitors) against factor VIII, which neutralizes the substituted factor. The primary genetic risk factors influencing the development of inhibitors are F8 gene mutations. Interleukins and cytokines that are involved in the regulation of B-lymphocyte development are other possible targets as genetic risk factors. This study assesses the possible involvement of 9 selected single nucleotide gene polymorphisms (SNPs) with interleukins (IL-4, IL-5, and IL-10), transforming growth factor beta 1 (TGF-β1), and interferon gamma (IFN-γ) in inhibitor development in severely affected HA patients carrying a null mutation in the F8 gene.

MATERIALS AND METHODS

A total of 173 HA patients were screened for intron 22 inversion and null mutations (nonsense and deletions). Genotyping of a total of 9 SNPs in genes IL-4, IL-5, IL-10, TGF-β1, and IFN-γ in 103 patients and 100 healthy individuals was carried out.

RESULTS

An association analysis between 42 inhibitor (+) and 61 inhibitor (-) patients showed a significant association with the T allele of rs2069812 in the IL-5 gene promoter and patients with inhibitors (p=0.0251). The TT genotype was also significantly associated with this group with a p-value of 0.0082, odds ratio of about 7, and confidence interval of over 90%, suggesting that it is the recessive susceptibility allele and that the C allele is the dominant protective allele.

CONCLUSION

The lack of other variants in the IL-5 gene of patients and controls suggests that rs2069812 may be a regulatory SNP and may have a role in B-lymphocyte development, constituting a genetic risk factor in antibody development.

Association of the interleukin 15 (IL-15) gene polymorphisms with the risk of developing ulcerative colitis in Mexican individuals

Interleukin 15 (IL-15) is a Th1-related cytokine that triggers inflammatory cell recruitment with implications for pathogenesis in ulcerative colitis. The IL-15 gene is located within a 35 kb region of the q28-31 locus of chromosome 4. In the present work, the role of IL-15 gene polymorphisms as susceptibility markers for UC was evaluated. Seven polymorphisms of IL-15 (rs3806798, rs10833, rs4956403, rs2254514, rs2857261, rs10519613, and rs1057972) were genotyped by 5' exonuclease TaqMan genotyping assays in a group of 199 Mexican patients with UC and 698 Mexican Mestizo healthy unrelated individuals. UC patients and healthy controls showed similar distribution of the rs3806798, rs10833, rs4956403, rs2857261, rs10519613, and rs1057972 polymorphisms. The rs2254514 polymorphism was significantly associated with decreased risk of UC as compared to controls under both dominant and additive models (OR 0.62, Pdom = 0.014 and OR 0.65, Padd = 0.02). The rs2254514 CC genotype was associated with young age at diagnosis <40 years (P = 0.03; OR 3.67). Five polymorphisms (rs1051613, rs2254514, rs2857261, rs1057972, and rs10833) were in strong linkage disequilibrium and were included in six haplotypes: H1 (ACAAC), H2 (CCGTC), H3 (CTAAT), H4 (CCAAT), H5 (CTAAC), and H6 (CCAAC). UC patients showed an increased frequency of the H6 haplotype (P = 0.005; OR 3.2) and a decreased frequency of the H5 haplotype (P = 0.031; OR 0.40). These results suggest that the IL-15 rs2254514 polymorphism might have an important role in the development of UC in the Mexican population. We were able to distinguish one risk and one protective uncommon haplotype for the development of UC.

Application of multi-SNP approaches Bayesian LASSO and AUC-RF to detect main effects of inflammatory-gene variants associated with bladder cancer risk

The relationship between inflammation and cancer is well established in several tumor types, including bladder cancer. We performed an association study between 886 inflammatory-gene variants and bladder cancer risk in 1,047 cases and 988 controls from the Spanish Bladder Cancer (SBC)/EPICURO Study. A preliminary exploration with the widely used univariate logistic regression approach did not identify any significant SNP after correcting for multiple testing. We further applied two more comprehensive methods to capture the complexity of bladder cancer genetic susceptibility: Bayesian Threshold LASSO (BTL), a regularized regression method, and AUC-Random Forest, a machine-learning algorithm. Both approaches explore the joint effect of markers. BTL analysis identified a signature of 37 SNPs in 34 genes showing an association with bladder cancer. AUC-RF detected an optimal predictive subset of 56 SNPs. 13 SNPs were identified by both methods in the total population. Using resources from the Texas Bladder Cancer study we were able to replicate 30% of the SNPs assessed. The associations between inflammatory SNPs and bladder cancer were reexamined among non-smokers to eliminate the effect of tobacco, one of the strongest and most prevalent environmental risk factor for this tumor. A 9 SNP-signature was detected by BTL. Here we report, for the first time, a set of SNP in inflammatory genes jointly associated with bladder cancer risk. These results highlight the importance of the complex structure of genetic susceptibility associated with cancer risk.

Four genetic polymorphisms of lymphotoxin-alpha gene and cancer risk: a systematic review and meta-analysis

Lymphotoxin-alpha (LTA) is a pro-inflammatory cytokine that plays an important role in the inflammatory and immunologic response. Numerous studies have shown LTA polymorphisms as risk factors for cancers, but the results remain inconclusive. The goal of the present meta-analyses is to establish the associations between cancers and four LTA variants (rs1041981, rs2239704, rs2229094 and rs746868). A total of 30 case-control studies involving 58,649 participants were included in the current meta-analyses. Our results showed significant associations with increased cancer risk for rs1041981 (odd ratio (OR) = 1.15, 99% confidential interval (CI) = 1.07-1.25, P < 0.0001, I² = 12.2%), rs2239704 (OR = 1.08, 99% CI = 1.01-1.16, P = 0.021, I² = 0.0%) and rs2229094 (OR = 1.28, 99% CI = 1.09-1.50, P = 0.003, I² = 0.0%). No evidence was found for the association between rs746868 and cancer risk (OR = 1.01, 99% CI = 0.93-1.10, P = 0.771, I² = 0.0%). Subgroup meta-analysis suggested that rs2239704 was likely to increase the risk of hematological malignancy (OR = 1.10, 99% CI = 1.01–1.20, P = 0.023, I² = 0.0%), and rs2229094 was specific for the increased risk of adenocarcinoma (OR = 1.33, 99% CI = 1.11-1.59, P = 0.002, I² = 0.0%). In conclusion, our meta-analyses suggested that the LTA rs1041981, rs2239704 and rs2229094 polymorphisms contributed to the increased risk of cancers. Future functional studies were needed to clarify the mechanistic roles of the three variants in the cancer risk.

Association between cytotoxic T lymphocyte antigen-4 +49A/G, -1722T/C, and -1661A/G polymorphisms and cancer risk: a meta-analysis

Cytotoxic T lymphocyte antigen-4 (CTLA-4), a key gene that contributes to the susceptibility and clinical course of cancer, is an important down-regulator of T cell activation and proliferation. The +49A/G polymorphism is commonly studied because of its association with cancer risks. However, other polymorphisms, such as -1722T/C and -1661A/G, have not been studied in detail. We performed a meta-analysis using 43 eligible case-control studies with a total of 19,089 patients and 21,388 controls to examine the association between CTLA-4 +49A/G, -1722T/C, and -1661A/G polymorphisms and cancer risk. We searched the PubMed and EMBASE databases for all articles published up to July 17, 2013. Individuals with the +49 A allele (AA/AG vs. GG, odds ratio (OR) = 1.21, 95% confidence interval (95% CI) = 1.16-1.27) and -1661 G allele (AG/GG vs. AA, OR = 1.52, 95% CI = 1.34-1.73) had increased cancer risk. However, no significant association between cancer risk and the -1722T/C polymorphism was found (CC/CT vs. TT, OR = 1.04, 95% CI = 0.92-1.16). In subgroup analysis for the +49A/G polymorphism, increased cancer risk remained in the subgroups of Asians (OR = 1.25, 95 % CI = 1.18-1.31), patients with breast cancer (OR = 1.28, 95% CI = 1.15-1.42), and patients with lung cancer (OR = 1.20, 95 % CI = 1.07-1.35). For the -1661A/G polymorphism, increased cancer risk remained in the subgroups of Asians (OR = 1.52, 95% CI = 1.34-1.73), patients with breast cancer (OR = 1.48, 95% CI = 1.07-2.03), and patients with oral cancer (OR = 3.16, 95% CI = 1.84-5.45). However, no significant increase in cancer risk was found in the subgroups for the -1722T/C polymorphism. In conclusion, the results suggest that +49A/G and -1661A/G polymorphisms in CTLA-4 are risk factors for cancers, whereas the -1722T/C polymorphism is not associated with an increased risk of cancer.

Positive association between lymphotoxin-alpha variation rs909253 and cancer risk: a meta-analysis based on 36 case-control studies

Lymphotoxin-alpha (LTA) polymorphism rs909253 has been reported to be a risk factor for cancers, but some results are inconsistent. To establish a more conclusive association, we performed a meta-analysis of this variant with cancers. A systematic search was performed for informative case-control studies of rs909253 with cancers among literature databases, including PubMed, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), and Wanfang Chinese Periodical Database. After a comprehensive filtration procedure, 36 publications involved with 35,677 participants were selected for the current meta-analysis. Stratified factors, such as cancer type, populations, and source of control, were used for a better interpretation of this variant. Minimal heterogeneity was shown in the current meta-analysis (I (2) = 0.0%, P = 0.48). Our results show a significant association of rs909253 and cancer risk (odds ratio (OR) = 1.12, P (z) < 0.001). In the subgroup analysis, significant association of rs909253 was found in adenocarcinoma (OR = 1.16, P (z) < 0.001) and hematological malignancy (OR = 1.10, P (z) < 0.001). Our meta-analyses established a significant association of rs909253 with cancer risk among multiple populations including North Americans, Asians, and Europeans.

Systemic cytokine levels and subsequent risk of gastric cancer in Chinese Women

Although control of the host cytokine network is known to influence gastric cancer susceptibility, the specific inflammatory responses in gastric carcinogenesis remain unclear. We prospectively examined the relationships between gastric cancer risk and plasma levels of interleukin (IL)-1β, IL-6, IL-8 and tumor necrosis factor (TNF)-α in a nested case control study within The Shanghai Women's Health Study. Two controls were matched to each case on the basis of age, menopausal status, and sample collection parameters. The associations between gastric cancer risk and tertiles of cytokine levels were estimated by odds ratios (OR) and 95% confidence intervals (CI) from conditional logistic regression, adjusting for education. During a median follow-up period of 4 years (range 0.1-8 years), 141 women developed gastric cancer and were matched to 282 cancer-free study participants. Elevated levels of plasma IL-6 were associated with an increased risk of gastric cancer (P(trend) = 0.04). Risk increased 70% (OR = 1.7; 95% CI 1.0, 3.0) for women in the highest tertile (>4 pg/mL) of IL-6 compared with those in the lowest tertile (<1.8 pg/mL). The association between gastric cancer risk and IL-6 was stronger after 4 years of follow-up (OR = 2.6 [95% CI 1.0, 6.7] for highest versus lowest tertile) compared with an OR of 1.4 (95% CI 0.7, 2.9) for those diagnosed within 1-4 years of follow-up. No associations were observed with the other pro-inflammatory cytokines examined, namely IL-1β, IL-8, and TNF-α. Systemic plasma IL-6 levels may inform long-term gastric cancer risk. This novel finding awaits confirmation in future studies with sequential plasma collection.

Polymorphisms in the cytotoxic T-lymphocyte antigen 4 gene and cancer risk: a meta-analysis

BACKGROUND

Polymorphisms in the cytotoxic T-lymphocyte antigen 4 (CTLA-4) gene have been implicated in susceptibility to cancer, but the many published studies have reported inconclusive results. The objective of the current study was to conduct a meta-analysis investigating the association between polymorphisms in the CTLA-4 gene and the risk of cancer.

METHODS

The PubMed and EMBASE databases were searched for all articles published up to September 19, 2010 that addressed cancer and polymorphisms, variants, or mutations of CTLA-4. A statistical analysis was performed using proprietary statistical software.

RESULTS

Three polymorphisms (+49 adenine/guanine [+49A/G], -318 cytosine/thymine [-318C/T], and the +6230G/A polymorphism [CT60]) in 48 case-control studies from 27 articles were analyzed. The results indicated that individuals who carried the +49 G allele (AG + GG) had a 16% decreased risk of cancer compared with homozygotes (+49AA; odds ratio [OR], 0.84; 95% confidence interval [CI], 0.74-0.95). However, there was no significant association between the risk of cancer and the -318C/T polymorphism or the CT60 polymorphism (-318C/T: OR, 1.23; 95% CI, 0.99-1.54 for TT + TC vs CC; CT60: OR, 1.02; 95% CI, 0.80-1.29 for AA + AG vs GG). In further stratified analyses for the +49A/G and -318C/T polymorphisms, the decreased risk of cancer remained in subgroups of Europeans, patients with breast cancer, and patients with lung cancer for the +49A/G polymorphism; whereas an increased risk of cancer was observed among Europeans for the -318C/T polymorphism.

CONCLUSIONS

Results from the current meta-analysis suggested that the +49A/G and -318C/T polymorphisms in CTLA-4 are risk factors for cancer. To further evaluate gene-gene and gene-environment interactions between CTLA-4 polymorphisms and the risk of cancer, more studies with larger groups of patients will be required.

Polymorphisms in chemokine and receptor genes and gastric cancer risk and survival in a high risk Polish population

OBJECTIVE

To examine if genetic variations in chemokine receptor and ligand genes are associated with gastric cancer risk and survival.

METHODS

The study included 298 cases and 417 controls from a population-based study of gastric cancer conducted in Warsaw, Poland in 1994-1996. We investigated seven single nucleotide polymorphisms in a chemokine ligand (CXCL12) and chemokine receptor (CCR2, CCR5, CX3CR1) genes and one frameshift deletion (CCR5) in blood leukocyte DNA in relation to gastric cancer risk and survival. Genotyping was conducted at the NCI Core Genotyping Facility. Odds ratios and 95% confidence intervals were computed using univariate and multivariate logistic regression models. Survival analysis was performed using Cox proportional hazards models.

RESULTS

Gastric cancer risk was not associated with single chemokine polymorphisms. A CCR5 haplotype that contained the common alleles of IVS1+151 G>T (rs2734648), IVS2+80 C>T (rs1800024) and minor allele of IVS1+246 A>G (rs1799987) was associated with a borderline significantly increased risk (OR = 1.5, 95% CI: 1.0?2.2). For gastric cancer cases, there was a greater risk of death for carriers of the minor alleles of CCR2 Ex2+241 G>A (rs1799864) (HR = 1.5, 95% CI: 1.1-2.1) and CCR5 IVS2+80 C>T (rs1800024) (HR = 1.5, 95% CI: 1.1-2.1). Carriers of the CCR5 minor allele of IVS1+151 G>T (rs2734648) had a decreased risk of death compared to homozygote carriers of the common allele (HR = 0.8, 95% CI: 0.6-1.0).

CONCLUSIONS

Our findings do not support an association between gastric cancer risk and single chemokine genetic variation. The observed associations between cancer risk and a CCR5 haplotype and between survival and polymorphisms in CCR2 and CCR5 need replication in future studies.

Evaluations of interferon-γ/interleukin-4 ratio and neutrophil/lymphocyte ratio as prognostic indicators in gastric cancer patients

BACKGROUND AND OBJECTIVES

Th2-dominant immunity and high neutrophil/lymphocyte ratios (NLRs) have been reported to reflect tumor progression, and so we examined whether the Th1/Th2 ratio and NLR can act as prognostic indicators or not.

METHODS

Peripheral blood samples were taken within 1 week before and 14 postoperative days after curative gastrectomy using 157 gastric cancer cases for the measurement of both ratios. The proportions of Th1 cells (interferon γ-producing CD4 T cells), Th2 cells (interleukin-4-producing CD4 T cells) were counted by two-color flow cytometry analysis.

RESULTS

There were significant differences in 5-year survival both between the high and low Th1/Th2 ratio groups, and between the high and low NLR groups. The pattern classifications before and after surgery in the Th1/Th2 ratio showed strongly significant differences in 5-year survival. NLR was especially influenced by tumor size, and there was a negative linear correlation between the two ratios before surgery.

CONCLUSIONS

The Th1/Th2 ratio may be a good prognostic indicator and may also be a promising marker for estimating the effectiveness of surgery. NLR may also be a good prognostic indicator and may be a valid marker of tumor recurrence, and it appeared that some interaction between lymphocytes and neutrophils had occurred.

Helicobacter pylori infection, host genetics and gastric cancer

Helicobacter pylori infects half the world's population and is responsible for a considerable global health burden, including peptic ulcer disease and gastric cancer. The infection causes a chronic gastritis, the severity and distribution of which determine the clinical outcome. Bacterial, environmental and host genetic factors combine to define the degree of gastric damage. Most patients have a limited mild pan-gastritis with no significant clinical consequences. Antral-predominant gastritis is associated with high gastric acid output and an increased risk of duodenal ulcers. Corpus-predominant gastritis is associated with a reduction in gastric acid, multifocal gastric atrophy and an increased risk of gastric cancer. Host genetic factors are particularly important in defining the severity and extent of Helicobacter-induced gastritis. The most relevant and consistent genetic factors uncovered thus far are in the interleukin-1 and tumor necrosis factor-A gene clusters. These cytokines appear to play a key role in the pathophysiology of gastric cancer and their roles have been confirmed in animal models that mimic human gastric neoplasia. More genetic factors have also been uncovered and, with advancing technology, there is every prospect of defining a full genetic risk profile in the next decade. This will aid in targeting the testing and treatment of Helicobacter pylori, which offers a true opportunity to prevent and defeat this global killer.