Prospective study of interaction between alcohol, NSAID use and polymorphisms in genes involved in the inflammatory response in relation to risk of colorectal cancer

The Association Between IL-8 Gene Polymorphisms and the Risk of Several Types of Cancer, Especially in Gastric Cancer

BACKGROUND

Changes in functional genetic polymorphisms may increase or decrease the risk of cancer in patients. Nowadays, the association between polymorphisms in the interleukin-8 (IL-8) gene and the susceptibility of cancer risk have been investigated in many studies, however, above relationships remain unclear.

AIM

The current study aims to comprehensively evaluate the association between IL-8 gene six polymorphisms and the whole cancer risk, especially -251 polymorphism and gastric cancer.

METHODS AND RESULTS

Six polymorphisms (-251, -353, +678, +1633, +2767, +781) were collected. The expression of serum IL-8 was calculated by ELISA assay. First, 104 case-control studies were conducted. Second, this research has made significant discoveries regarding the -251, -353 and +781 polymorphisms and the potential associations with cancer risk. Finally, the serum IL-8 levels in gastric cancer patients with AA/TT genotypes were significantly higher than those with the same genotypes of healthy controls and TT genotypes in gastric cancer patients.

CONCLUSION

Overall, the investigation has revealed that IL-8 gene polymorphisms significantly influence vulnerability to cancer development, especially for gastric cancer.

A Meta-Analysis of Association Between Interleukin Polymorphisms (rs4073, rs1800925, rs1179251, rs1179246, rs2227485, rs17855750, and rs153109) and Colorectal Cancer Risk

Interleukins (ILs) play a significant role in triggering the inflammatory response in blood vessels and immune cells. A systematic review and meta-analysis were conducted to investigate the relationship between IL-8 (rs4073), IL-13 (rs1800925), IL-22 (rs1179251, rs1179246, and rs2227485), and IL-27 (rs17855750 and rs153109) polymorphisms and the risk of developing colorectal cancer (CRC). Four databases were searched up until October 13, 2023, without any restrictions, to find relevant studies. The association was evaluated using crude odds ratios (ORs) and 95% confidence intervals in five genetic models. A total of twenty-three articles were entered into the meta-analysis. The pooled ORs (p-values) for the IL-8 (rs4073) polymorphism were 0.98 (0.63), 0.93 (0.44), 0.89 (0.13), 0.94 (0.38), and 0.99 (0.90) for studies following HWE without heterogeneity, and for all studies with high heterogeneity were 1.03 (0.69), 1.30 (0.07), 1.04 (0.71), 1.12 (0.20), and 1.23 (0.06). For the IL-13 (rs1800925) polymorphism, the pooled ORs were 1.44 (0.06), 2.58 (0.0004), 1.72 (0.16), 1.82 (0.09), and 2.37 (0.001) in AHHDR models, respectively. The pooled ORs of IL-22 (rs1179251) polymorphism for AHHDR models were 0.97 (0.92), 0.92 (0.90), 0.98 (p = 0.95), 1.08 (0.87), and 0.96 (0.82), respectively. The pooled ORs of IL-22 (rs1179246) polymorphism for AHHDR models were 0.98 (0.67), 0.97 (0.80), 0.92 (0.36), 0.93 (0.42), and 1.02 (0.84), respectively. The pooled ORs of IL-22 (rs2227485) polymorphism for AHHDR models were 1.47 (0.02), 2.03 (0.02), 1.28 (0.29), 1.52 (0.06), and 1.70 (0.04), respectively. The pooled ORs of IL-27 (rs17855750) polymorphism for AHHDR models were 0.53 (0.46), 0.19 (0.28), 1.10 (0.60), 0.55 (0.58), and 0.27 (p = 0.05), respectively. The pooled ORs of IL-27 (rs153109) polymorphism for AHHDR models were 1.28 (0.007), 1.45 (0.002), 1.40 (0.0002), 1.41 (< 0.0001), and 1.20 (0.09), respectively. The results reported that just the TT genotype of IL-13 (rs1800925), the T allele and TT genotype of IL-22 (rs2227485), and the G allele and GG, AG and GG + AG genotypes of IL-27 (rs153109) polymorphisms had an elevated risk in CRC patients.

Identification and analysis of the molecular targets of statins in colorectal cancer

Colorectal cancer (CRC) is the third most common cancer in the world. According to several types of research, statins may impact the development and treatment of CRC. This work aimed to use bioinformatics to discover the relationship between statin targets and differentially expressed genes (DEGs) in CRC patients and determine the possible molecular effect of statins on CRC suppression. We used CRC datasets from the GEO database to select CRC-related DEGs. DGIdb and STITCH databases were used to identify gene targets of subtypes of statin. Further, we identified the statin target of CRC DEGs hub genes by using a Venn diagram of CRC DEGs and statin targets. Funrich and enrichr databases were carried out for the KEGG pathway and gene ontology (GO) enrichment analysis, respectively. GSE74604 and GSE10950 were used to identify CRC DEGs. After analyzing datasets,1370 genes were identified as CRC DEGs, and 345 targets were found for statins. We found that 35 genes are CRC DEGs statin targets. We found that statin targets in CRC were enriched in the receptor and metallopeptidase activity for molecular function, cytoplasm and plasma membrane for cellular component, signal transduction, and cell communication for biological process genes were substantially enriched based on FunRich enrichment. Analysis of the KEGG pathways revealed that the overexpressed DEGs were enriched in the IL-17, PPAR, and Toll-like receptor signaling pathways. Finally, CCNB1, DNMT1, AURKB, RAC1, PPARGC1A, CDKN1A, CAV1, IL1B, and HSPD1 were identified as hub CRC DEGs statin targets. The genetic and molecular aspects of our findings reveal that statins might have a therapeutic effect on CRC.

The Significant Impacts of Interleukin-8 Genotypes on the Risk of Colorectal Cancer in Taiwan

Interleukin-8 (IL-8), a pro-inflammatory cytokine, is upregulated in CRC and plays an important role in its development and progression. Genetic variants in the IL-8 gene may impact the risk of CRC by modulating IL-8 levels. Our primary objective was to investigate the role of IL-8 genotypes in the development of CRC. To accomplish this, we employed the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to analyze the genotypes of IL-8 rs4017, rs2227306, rs2227543, and rs1126647 in 362 CRC patients and 362 controls. Additionally, we evaluated the interactions between these genotypes and factors such as age, gender, smoking, alcohol consumption, and body mass index (BMI) status in relation to the risk of CRC. Furthermore, we utilized quantitative reverse transcription-PCR to measure the serum IL-8. The results demonstrated a significant difference in the distribution of rs4017 genotypes between the control and case groups (p for trend = 0.0059). Logistic regression analysis revealed that individuals with variant AA genotype had a 1.92-fold higher CRC risk (95% confidence interval [CI] = 1.28-2.89, p = 0.0023). Moreover, carriers of the IL-8 rs4017 AT + AA genotypes exhibited a significant association with CRC risk (odds ratio [OR] = 1.39, 95% CI = 1.02-1.91, p = 0.0460). Additionally, individuals with IL-8 rs4017 AA genotype displayed significantly elevated serum IL-8 compared to those with TT genotype at a 1.73-fold level (p < 0.0001), indicating a correlation between genotype and phenotype. In conclusion, the genotypes of IL-8 rs4017, along with their associated expression levels, can potentially serve as predictive markers for the risk of CRC.

The Effect of IL-6 174G > C Gene Polymorphism on Gastrointestinal Cancer: a Systematic Review and Meta-analysis

IL-6 gene polymorphisms can play a role in the development or control of cancer by affecting cytokines. Gastrointestinal cancer is one of the most common types of cancer worldwide. The aim of this study was to investigate the effect of polymorphism of the IL-6 174G > C gene on gastrointestinal cancers based on a systematic review and meta-analysis, including gastric, colorectal, and esophageal cancer. In this study, a systematic and meta-analytical review of the study data on the effect of polymorphism of IL-6 174G > C gene on gastrointestinal cancer (gastric, colorectal, and esophageal cancer) in Scopus, EMBASE, Web of Science, PubMed, and Science Direct Databases was extracted without any time limit until April 2020. In order to perform the analysis of eligible studies, the model of random effects was used and the heterogeneity of studies was investigated with I2 index. Data analysis was performed with Comprehensive Meta-Analysis software (Version 2). The total number of surveyed studies in patients with colorectal cancer was 22 studies. Based on the results of meta-analysis, the odds ratio of GG genotype in patients with colorectal cancer was 0.88. The odds ratio of GC genotype obtained in patients with colorectal cancer was 0.88 and the odds ratio of CC genotype in patients with colorectal cancer was 0.92. The total number of surveyed studies in patients with gastric cancer was 12. Based on the meta-analysis results, the odds ratio of GG genotype in patients with gastric cancer was 0.74, the odds ratio of GC genotype in patients with gastric cancer was 1.27, and the odds ratio of CC genotype in patients with gastric cancer was 0.78. The total number of surveyed studies in esophageal cancer patients was 3 studies. Based on the results of meta-analysis, the odds ratio of GG genotype in patients with esophageal cancer was 0.57, the odds ratio of GC genotype in patients with esophageal cancer was 0.44, and the odds ratio of chance of CC genotype in patients with esophageal cancer was 0.99. In general, different genotypes of polymorphism of the IL-6 174G > C gene reduce the risk of gastric, colorectal, and esophageal cancer. However, the GC genotype of this gene was associated with a 27% increased risk of gastric cancer.

A double-edged sword: DLG5 in diseases

Discs large homolog 5 (DLG5), a key member of the membrane-associated guanylate kinase (MAGUKs) family, is a scaffold molecule for signal transduction complexes and is responsible for assembling receptors and adapters. This scaffold protein stabilizes adhesion and tight bonding complexes in many organs and tissues, and is involved of maintaining epithelial polarity. Although DLG5 plays a role in normal development in mice, it has also been linked to the onset and development of several diseases, particularly Crohn's disease and various malignancies. DLG5 has been shown to impact the progression of cancer through direct or indirect interactions with H-catenin, E-cadherin, Vimentin, p53, P21, Cyclin D1, TGF-β1, AKT, Hippo, and classic G protein signaling pathways. DLG5 and DLG5 variants has been found to have a dual role in human diseases. Although it is overexpressed in pancreatic adenocarcinoma, its expression is reduced in lung, liver, breast, prostate, and bladder cancers. However, two independent studies on glioblastoma (GBM) have shown the opposite effects of DLG5. Our study evaluates the existing literature on the role of DLG5 and DLG5 variants in disease processes, and summarizes the available data on the role of DLG5 in disease based on cell experiments, clinical samples, and animal models, while highlighting its future potential in disease treatment.

Association of Interleukin-10 Polymorphisms with Susceptibility to Colorectal Cancer and Gastric Cancer: an Updated Meta-analysis Based on 106 Studies

BACKGROUND

The purpose of this study was to explore the association of IL-10 polymorphisms with susceptibility to colorectal cancer (CRC) and gastric cancer (GC).

METHODS

PubMed, Scopus, Embase, SciELO, medRxiv, China Biology Medicine Disc, DeepDyve, CNKI, and Web of Science were used to identify all relevant articles published up to 20th June 2021, without any restrictions on ethnicity. Summary odds ratios (ORs) with 95% confidence intervals (CIs) were used to determine the strength of the associations.

RESULTS

A total of 106 case-control studies were included. For CRC, 15 studies with 2772 cases and 3719 controls on -1082A/G, 11 studies with 3259 cases and 4992 controls on -592C/A, and 3 studies with 477 cases and 544 controls on -819 T/C were selected. For GC, 31 studies with 6229 cases and 8666 controls on -1082A/G, 27 studies with 5457 cases and 8381 controls on -592C/A, and 19 studies with 3556 cases and 6218 controls on -819 T/C were included. Pooled data showed a significant association between IL-10-819 T/C polymorphism and CRC susceptibility in overall population, but not for IL-10-1082A/G and -592C/A polymorphisms. However, IL-10-592C/A polymorphism was associated with CRC risk in Asians. A significant association of IL-10-1082A/G polymorphism with the GC risk was found. In the ethnicity subgroup analysis, a significant association was found between IL-10-1082A/G polymorphism and GC risk among Asians. The IL-10-819 T/C was not associated with GC risk in overall population and by ethnicity.

CONCLUSIONS

Our pooled data show a significant association of IL-10-819 T/C and IL-10-1082A/G polymorphisms with CRC and GC in overall population, respectively. However, other factors may influence these associations, and large-scale studies with adequate methodological quality are necessary to confirm the impact on CRC and GC risk.

Peroxisome Proliferator-Activated Receptor Gamma Pro12Ala/C161T Genotypes and Risky Haplotype Altering Risk of Breast Cancer: A Turkish Case-Control Study

Breast cancer (BC) has a high incidence rate among women worldwide, and the mechanisms and etiology of this disease are not yet fully understood. The peroxisome proliferator-activated receptor gamma (PPARgamma), a nuclear hormone receptor that plays important roles in energy metabolism and cellular differentiation, is also suggested to be effective in cancer development. However, the results of studies investigating the cancer association with PPARgamma are inconsistent, creating a need for further investigation of the effects of this transcription factor on BC risk. We have examined the Pro12Ala-(rs1801282) and C161T-(rs3856806) polymorphisms of the PPARgamma gene in Turkish patients with BC in this case-control study. A total of 95 women diagnosed with BC as cases and 119 controls were genotyped for PPARgamma polymorphisms by polymerase chain reaction and restriction fragment length polymorphism techniques. The ProPro genotype and T161 allele were associated with an increased risk of BC comparing with the Ala12 allele and CC161 genotype, respectively (p < 0.001). The multivariate regression analysis confirmed that the ProPro genotype (p < 0.011), T161 allele (p < 0.001), smoking (p = 0.019), and advanced age (> 60 years) (p = 0.007) are risk factors for breast cancer. We also found that the PPARgamma Pro12Ala and C161T polymorphisms were in linkage disequilibrium (D':0.511, r²:0.099). It was determined that carrying ProPro-T161 risky PPARgamma haplotype was associated with a higher risk of BC compared to protective Ala12-CC161 haplotype (p < 0.01, OR:7.797, 95% CI:3.521-17.263). We concluded that PPARgamma Pro12Ala and C161T polymorphisms are associated with increased BC risk, and ProPro-T161 risky haplotype, which is in linkage disequilibrium, increases this effect.

Diet and PPARG2 Pro12Ala Polymorphism Interactions in Relation to Cancer Risk: A Systematic Review

Peroxisome proliferator-activated receptor-γ2 gene Pro12Ala allele polymorphism (PPARG2 Pro12Ala; rs1801282) has been linked to both cancer risk and dietary factors. We conducted the first systematic literature review of studies published before December 2020 using the PubMed database to summarize the current evidence on whether dietary factors for cancer may differ by individuals carrying C (common) and/or G (minor) alleles of the PPARG2 Pro12Ala allele polymorphism. The inclusion criteria were observational studies that investigated the association between food or nutrient consumption and risk of incident cancer stratified by PPARG2 Pro12Ala allele polymorphism. From 3815 identified abstracts, nine articles (18,268 participants and 4780 cancer cases) covering three cancer sites (i.e., colon/rectum, prostate, and breast) were included. CG/GG allele carriers were more impacted by dietary factors than CC allele carriers. High levels of protective factors (e.g., carotenoids and prudent dietary patterns) were associated with a lower cancer risk, and high levels of risk factors (e.g., alcohol and refined grains) were associated with a higher cancer risk. In contrast, both CG/GG and CC allele carriers were similarly impacted by dietary fats, well-known PPAR-γ agonists. These findings highlight the complex relation between PPARG2 Pro12Ala allele polymorphism, dietary factors, and cancer risk, which warrant further investigation.

Cumulative Evidence for Association Between IL-8 -251T>A and IL-18 -607C>A Polymorphisms and Colorectal Cancer Susceptibility: a Systematic Review and Meta-analysis

PURPOSE

The correlation of IL-8 and IL-18 gene polymorphisms with colorectal cancer (CRC) was investigated by previous studies, though the results remained conflicting. Thus, the meta-analysis was performed to investigate the association of IL-8 -251T>A and IL-18 -607C>A polymorphisms with CRC risk.

METHODS

A comprehensive search of the PubMed, Web of Science, CNKI, SciELO, and Wanfang databases was performed up to February 20, 2020. The strength of the associations was calculated with odds ratios (ORs) and their corresponding 95% of confidence intervals (CIs).

RESULTS

A total of 16 case-control studies including 13 studies with 3908 cases and 5005 controls on IL-8 -251T>A polymorphism and three studies with 396 cases and 560 controls on IL-18 -607C>A polymorphism were selected. Pooled data revealed that the IL-8 -251T>A and IL-18 -607C>A polymorphisms were not significantly associated with an increased risk of CRC in global population. When stratified by ethnicity, source of controls, sample size, and Hardy-Weinberg equilibrium (HWE), there were still no significant association between IL-8 -251T>A polymorphism and risk of CRC.

CONCLUSIONS

Our results revealed that the IL-8 -251T>A and IL-18 -607C>A polymorphisms were not associated with an increased susceptibility to CRC. We strongly call for further studies with larger sample sizes and different ethnicities to confirm our findings.

Association of IL-6 −174 G>C Polymorphism with Susceptibility to Colorectal Cancer and Gastric Cancer: a Systematic Review and Meta-Analysis

Background: The −174G>C (rs1800795) polymorphism at interleukin 6 (IL-6) gene has been reported to be related with the occurrence of colorectal (CRC) and gastric (GC) cancers. However, the results had been conflicting and controversial. In order to give a comprehensive and precise result, we summarized available data to analyze the association of this polymorphism with CRC and GC risk. Methods: A comprehensive literature search on PubMed, Elsevier Science Direct, and CNKI database was performed to identify all eligible studies up to May 15, 2019. The strength of association was assessed by odds ratios (ORs) with 95% confidence intervals (CI). Results: A total of 29 case-control studies including 16 studies with 7,560 cases and 9,574 controls on CRC and 13 studies with 1,445 cases and 2,918 controls on GC were selected. Overall, pooled data showed that the IL-6 −174G>C polymorphism was not significantly associated with increased risk of CRC and GC in overall. When stratified by ethnicity, we found a statistically significant association between the IL-6 −174 G>C polymorphism and CRC risk in Asians (CC vs. GG: OR = 1.860, 95% CI 1.061–3.258, p = 0.030; and CC vs. CG+GG: OR = 1.941, 95% CI 1.131–3.331, p = 0.016). Conclusion: The meta-analysis suggests that IL-6 −174G>C polymorphism was not significantly associated with the increased risk of CRC and GC in overall population. However, the results showed that IL-6 −174G>C polymorphism may be associated with risk of GC in Asians. Further studies including a larger sample size will be necessary to clarify these results.

No Interaction between Polymorphisms Related to Vitamin A Metabolism and Vitamin A Intake in Relation to Colorectal Cancer in a Prospective Danish Cohort

Although vitamin A is essential for gut immune cell trafficking (paramount for the intestinal immune system), epidemiological studies on the role of vitamin A in colorectal cancer (CRC) aetiology are conflicting. By using functional polymorphisms, gene–environment (GxE) interaction analyses may identify the biological effects (or “mechanism of action”) of environmental factors on CRC aetiology. Potential interactions between dietary or supplemental vitamin A intake and genetic variation in the vitamin A metabolic pathway genes related to risk of CRC were studied. We used a nested case-cohort design within the Danish “Diet, Cancer and Health” cohort, with prospectively collected lifestyle information from 57,053 participants, and the Cox proportional hazard models and likelihood ratio test. No statistically significant associations between the selected polymorphisms and CRC, and no statistically significant interactions between vitamin A intake and the polymorphisms were found. In conclusion, no support of an involvement of vitamin A in CRC aetiology was found.

PPARG rs3856806 C>T Polymorphism Increased the Risk of Colorectal Cancer: A Case-Control Study in Eastern Chinese Han Population

Purpose: Functional variants in the peroxisome proliferator-activated receptor gamma (PPARG) and PPARG co-activator 1 (PPARGC1) family (e.g., PPARGC1A and PPARGC1B) genes were predicted to confer susceptibility to colorectal cancer (CRC). The aim of the present study was to explore the relationship between PPARG, PPARGC1A, PPARGC1B polymorphism and the risk of CRC.

Patients and methods: We conducted a case-control study with 1,003 CRC cases and 1,303 controls. We selected the PPARG rs3856806 C>T, PPARGC1A rs2970847 C>T, rs8192678 C>T, rs3736265 G>A and PPARGC1B rs7732671 G>C and rs17572019 G>A SNPs to assess the relationship between PPARG, PPARGC1A, PPARGC1B their variants and risk of CRC.

Results: We found that the PPARG rs3856806 C>T polymorphism increased the risk of CRC (TT vs. CC: adjusted OR, 1.59, 95% CI 1.08–2.35, P = 0.020; TT/CT vs. CC: adjusted OR, 1.26; 95% CI 1.06–1.49; P = 0.009 and TT vs. CC/CT: adjusted OR, 1.54; 95% CI 1.05–2.26; P = 0.028), even after a Bonferroni correction test. The stratified analysis revealed that the PPARG rs3856806 C>T polymorphism also increased the risk of CRC, especially in male, ≥61 years old, never smoking, never drinking, BMI ≥ 24 kg/m², colon cancer and rectum cancer subgroups.

Conclusion: Our findings highlight that the PPARG rs3856806 C>T polymorphism may increase the risk of CRC. In the future larger sample size case-control studies with a detailed functional assessment are needed to further determine the relationship of the PPARG rs3856806 C>T polymorphism with CRC risk.

ASSOCIATION OF PROMOTER REGION POLYMORPHISMS OF INTERLEUKIN-10 GENE WITH SUSCEPTIBILITY TO COLORECTAL CANCER: A SYSTEMATIC REVIEW AND META-ANALYSIS

BACKGROUND

Several epidemiological studies have investigated the association of promoter region polymorphisms of Interleukin-10 (IL-10) gene with colorectal cancer (CRC), while the conclusion is still conflicting and inconclusive.

OBJECTIVE

We conducted this meta-analysis to evaluate the association of promoter region polymorphisms of IL-10 with CRC.

METHODS

Eligible articles were identified by a search of several bibliographic databases for the period up to March 15, 2018. The strength of the association was measured by odd ratios with 95% confidence intervals.

RESULTS

A total of 28 case-control studies with 5,647 CRC cases and 6,908 controls were selected, including 14 studies for IL-10 -1082A>G (rs1800896) polymorphism (2,702 cases and 3,649 controls), eleven studies for -592C>A (rs1800872) polymorphism (3,259 cases and 4,992 controls), and three studies for -819T>C (rs1800871) polymorphism (477 cases and 544 controls). By pooling all eligible studies, we found that the IL-10 -1082A>G and -592C>A polymorphisms were not associated with increased CRC risk in overall population. However, there was significant associations between the IL-10 -819T>C polymorphism and CRC susceptibility under the allele model (A vs G: OR=1.278, 95% CI 1.043-1.566, P=0.018) and the recessive model (AA vs AG+GG: OR=1.709, 95% CI 1.026-2.845, P=0.039).

CONCLUSION

In this meta-analysis we found that IL-10 -819T>C polymorphism was associated with significantly increased risk of CRC; while the IL-10 -1082A>G and -592C>A polymorphisms were not associated with CRC risk. The IL-10 -819T>C polymorphism may be important as suspected predictive factor of CRC occurrence.

Relationship of PPARG, PPARGC1A, and PPARGC1B polymorphisms with susceptibility to hepatocellular carcinoma in an eastern Chinese Han population

Background

PPARG, PPARGC1A, and PPARGC1B polymorphisms may be implicated in the development of cancer.

Participants and methods

In this study, we selected PPARG rs1801282 C>G and rs3856806 C>T, PPARGC1A rs2970847 C>T, and PPARGC1B rs7732671 G>C and rs17572019 G>A single-nucleotide polymorphisms to explore the relationship between these polymorphisms and hepatocellular carcinoma (HCC) risk. A total of 584 HCC patients and 923 controls were enrolled.

Results

We found that PPARG rs1801282 C>G polymorphism was correlated with a decreased susceptibility of HCC (CG vs CC, adjusted OR 0.47, 95% CI 0.27-0.82, P=0.007; CG/GG vs CC, adjusted OR 0.52, 95% CI 0.31-0.88, P=0.015). However, PPARG rs3856806 C>T polymorphism was a risk factor for HCC (TT vs CC, adjusted OR 2.33, 95% CI 1.25-4.36, P=0.008; TT vs CT/CC, adjusted OR 2.26, 95% CI 1.22-4.17, P=0.010). In a subgroup analysis by chronic hepatitis B virus (HBV)-infection status, age, sex, alcohol use, and smoking status, a significant association between PPARG rs1801282 C>G polymorphism and a decreased risk of HCC in male, ≥53 years, never-smoking, never-drinking, and nonchronic HBV-infection-status subgroups was found. However, we found PPARG rs3856806 C>T polymorphism increased the risk of HCC in never-smoking, never-drinking, and nonchronic HBV-infection-status subgroups. Haplotype-comparison analysis indicated that C_rs1801282T_rs3856806C_rs2970847G_rs7732671G_rs17572019, C_rs1801282T_rs3856806T_rs2970847G_rs7732671G_rs17572019, and C_rs1801282C_rs3856806C_rs2970847C_rs7732671A_rs17572019 haplotypes increased the risk of HCC. PPARG C_rs1801282T_rs3856806 and G_rs1801282C_rs3856806 haplotypes also influenced the risk of HCC.

Conclusion

In conclusion, our findings suggest PPARG polymorphisms may influence the susceptibility of HCC. The PPARG, PPARGC1A, and PPARGC1B haplotypes might be associated with HCC risk.

Associations of interleukin-6 gene polymorphisms with cancer risk: Evidence based on 49,408 cancer cases and 61,790 controls

Many molecular epidemiologic studies have shown that interleukin-6 (IL-6) polymorphisms are significantly associated with susceptibility for various cancers. However, the conclusions of these studies are inconsistent. The purpose of the present study was to explore the association between three common IL-6 loci (rs1800795, rs1800796, and rs1800797) and the risk for various cancers. We systematically searched the PubMed, Web of Science, Wanfang and China national knowledge infrastructure (CNKI) databases for relevant publications and obtained 108 eligible studies, involving 49,408 cancer patients and 61,790 cancer-free controls. Odds ratio (OR), 95% confidence interval (CI), and false positive reporting probability (FPRP) were used to evaluate cancer risk. All statistical analyses were performed using the R software meta package. We observed a non-significant association between rs1800795 and overall cancer risk, while rs1800797 was found to have a false positive association with overall risk of cancer. Subgroup analyses of rs1800797 also suggested non-significant association and rs1800795 played a protective role in liver cancer. Rs1800796 was found to be associated with overall cancer risk, particularly in Asian patients and those with prostate cancer. These findings provide evidence that IL-6 polymorphisms may affect cancer risk.

Association between interleukin-10 -592 A/C polymorphism and gastrointestinal tract cancer risk: A meta-analysis

BACKGROUND

Recent evidence suggests that -592 A/C polymorphism in the interleukin-10 (IL-10) gene may influence risk of gastrointestinal tract cancer; however, individual studies have provided conflicting and inconclusive results. Therefore, this meta-analysis was conducted to assess the association between IL-10 -592 A/C polymorphism and gastrointestinal tract cancer susceptibility.

METHODS

EMBASE, PubMed, Web of Science, and China National Knowledge Infrastructure databases were searched for case-control studies published before 1 May 2017. A total of 36 studies involving 8069 cases and 13,089 controls were included in the present meta-analysis according to the inclusion criteria. The random- or fixed-effect model was utilized to calculate pooled odds ratio (OR) with 95% confidence interval (CI), and to survey the association.

RESULTS

By and large IL-10 -592 A/C (rs1800872) polymorphism was not associated with gastrointestinal cancer risk in five genetic models (A vs. C: OR 1.00; 95% CI 0.93, 1.08; P_OR = 0.960; AA vs. CC: OR 0.98; 95% CI 0.85, 1.14; P_OR = 0.835; CA vs. CC: OR 1.01; 95% CI 0.94, 1.08; P_OR = 0.776; AA+CA vs. CC: OR 1.03; 95% CI 0.94, 1.12; P_OR = 0.592; AA vs. CA+CC: OR 0.98; 95% CI 0.87, 1.10; P_OR = 0.666). Similar results were also achieved after stratification by the Hardy-Weinberg equilibrium, ethnicity, source of controls, and cancer type.

CONCLUSION

The results of this meta-analysis indicated that there is no association between the IL-10 -592 A/C promoter polymorphism and gastrointestinal tract cancer susceptibility.

Genetic variation in PPARGC1A may affect the role of diet-associated inflammation in colorectal carcinogenesis

The role of inflammation in colorectal carcinogenesis may differ according to individuals’ genetic variations. Therefore, we investigated whether genetic susceptibility alters the association between inflammatory potential of diet and the risk of colorectal cancer within the Korean population. We genotyped four polymorphisms in four genes (IL1B, TNF, PPARG, and PPARGC1A) and calculated the dietary inflammatory index (DII) in a case-control study with 701 colorectal cancer patients and 1,402 controls. Among the investigated polymorphisms, heterozygous carriers of rs3774921 in PPARGC1A showed a higher risk of colorectal cancer (OR [95% CI] = 1.26 [1.02–1.55] for TC vs. TT). When the data were stratified by rs3774921 genetic variant, the association of a pro-inflammatory diet with colorectal cancer risk was more prominent among homozygous variant allele carriers (OR [95% CI] = 5.15 [2.35–11.29] for high vs. low DII) (P for interaction = 0.009). When stratified by anatomic site, this association was much stronger for rectal cancer patients (OR [95% CI] = 8.06 [2.67–24.16] for high vs. low DII) (P for interaction = 0.006). Additionally, this interaction was stronger among those older than 50 years and not exercising regularly. Conversely, no association or interaction was found for the other investigated polymorphisms. In conclusion, the results of this study suggest that a pro-inflammatory diet may have a differential effect on colorectal cancer risk based on PPARGC1A genetic variation. This interaction may differ by anatomic location and other risk factors.

Genetic polymorphisms associated with psoriasis and development of psoriatic arthritis in patients with psoriasis

Background

Psoriasis (PsO) is a chronic inflammatory disease with predominantly cutaneous manifestations. Approximately one third of patients with PsO develop psoriatic arthritis (PsA), whereas the remaining proportion of patients has isolated cutaneous psoriasis (PsC). These two phenotypes share common immunology, but with different heredity that might in part be explained by genetic variables.

Methods

Using a candidate gene approach, we studied 53 single nucleotide polymorphisms (SNPs) in 37 genes that regulate inflammation. In total, we assessed 480 patients with PsO from DERMBIO, of whom 151 had PsC for 10 years or more (PsC10), 459 patients with PsA from DANBIO, and 795 healthy controls. Using logistic regression analysis, crude and adjusted for age and gender, we assessed associations between genetic variants and PsO, PsC10, and PsA, as well as associations between genetic variants and development of PsA in PsO.

Results

Eleven polymorphisms in 10 genes were nominally associated with PsO and/or PsC and/or PsA (P < 0.05). After correction for multiple testing with a false discovery rate of 5%, two SNPs remained significant: TNF (rs361525) was associated with PsO, PsC10, and PsA; and IL12B (rs6887695) was associated with PsO.

Conclusion

Among a cohort of Danish patients with moderate-to-severe psoriasis, two SNPs in the IL12B and TNF genes were associated with susceptibility of psoriasis. None of the SNPs were specifically associated with isolated cutaneous psoriasis or psoriatic arthritis.

Effects of interactions between common genetic variants and alcohol consumption on colorectal cancer risk

BACKGROUND

Genome-wide association studies (GWAS) have identified approximately 40 common genetic loci associated with colorectal cancer risk. To investigate possible gene-environment interactions (GEIs) between GWAS-identified single-nucleotide polymorphisms (SNPs) and alcohol consumption with respect to colorectal cancer, a hospital-based case-control study was conducted.

RESULTS

Higher levels of alcohol consumption as calculated based on a standardized definition of a drink (1 drink=12.5g of ethanol) were associated with increased risk of colorectal cancer (OR=2.47, 95% CI=1.62-3.76 for heavy drinkers [>50g/day] compared to never drinkers; ptrend<0.01). SNP rs6687758 near the DUSP10 gene at 1q41 had a statistically significant interaction with alcohol consumption in analyses of standardized drinks (p=4.6×10-3), although this did not surpass the corrected threshold for multiple testing. When stratified by alcohol consumption levels, in an additive model the risk of colorectal cancer associated with the G allele of rs6687758 tended to increase among individuals in the heavier alcohol consumption strata. A statistically significant association between rs6687758 and colorectal cancer risk was observed among moderate alcohol drinkers who consumed between >12.5 and ≤50g of alcohol per day (OR=1.46, 95% CI=1.01-2.11).

METHODS

A total of 2,109 subjects (703 colorectal cancer patients and 1,406 healthy controls) were recruited from the Korean National Cancer Center. For genotyping, 30 GWAS-identified SNPs were selected. A logistic regression model was used to evaluate associations of SNPs and alcohol consumption with colorectal cancer risk. We also tested GEIs between SNPs and alcohol consumption using a logistic model with multiplicative interaction terms.

CONCLUSIONS

Our results suggest that SNP rs6687758 at 1q41 may interact with alcohol consumption in the etiology of colorectal cancer.

Genetic polymorphisms of IL-6 promoter in cancer susceptibility and prognosis: a meta-analysis

IL-6 is critical for tumorigenesis. However, previous studies on the association of IL-6 promoter polymorphisms with predisposition to different cancer types are somewhat contradictory. Therefore, we performed this meta-analysis regarding the relationship between IL-6 promoter single nucleotide polymorphisms and cancer susceptibility and prognosis. Up to April 2017, 97 original publications were identified covering three IL-6 promoter SNPs. Our results showed statistically significant association between IL-6 promoter and cancer risk and prognosis. Subgroup analysis indicated that rs1800795 was significantly associated with increased risk of cervical cancer, colorectal cancer, breast cancer, prostate cancer, lung cancer, glioma, non-Hodgkin’s lymphoma and Hodgkin’s lymphoma but not gastric cancer and multiple myeloma. Furthermore, rs1800796 was significantly associated with increased risk of lung cancer, prostate cancer and colorectal cancer but not gastric cancer. Additionally, rs1800797 was significantly association with breast cancer, non-Hodgkin’s lymphoma, B-cell lymphoma and diffuse large B-cell lymphoma but not gastric cancer. Simultaneously, rs1800795 and rs1800796 were associated with a significantly higher risk of cancer in Asia and Caucasian, rs1800797 was associated with a significantly risk of cancer in Caucasian but not in Asia. Furthermore, IL-6 promoter polymorphisms were significantly associated with the prognosis of cancer. Considering these promising results, IL-6 promoter including rs1800795, rs1800796 and rs1800797 may be a tumor marker for cancer therapy.

PPARG c.1347C>T polymorphism is associated with cancer susceptibility: from a case-control study to a meta-analysis

Recently, several studies suggested that PPARG c.1347C>T polymorphism was correlated with cancer risk. However, past results remained controversial. In this study, we performed a case-control study on the relationship of PPARG c.1347C>T polymorphism with risk of non-small cell lung cancer (NSCLC) and subsequently carried out a meta-analysis to further assess the association between PPARG c.1347C>T and overall cancer. In our case-control study, after adjusting by age, sex, body mass index (BMI), smoking and drinking, a tendency to increased NSCLC risk was noted (CT/TT vs. CC: adjusted OR, 1.21; 95% CI, 0.97–1.51; P = 0.097). In the meta-analysis, we found a significant association between PPARG c.1347C>T polymorphism and overall cancer risk (T vs. C: OR, 1.13; 95% CI, 1.03–1.23; P = 0.006; TT vs. CC: OR, 1.29; 95% CI, 1.07–1.56; P = 0.008, CT/TT vs. CC: OR, 1.11; 95% CI, 1.02–1.21; P = 0.014 and TT vs. CT/CC: OR, 1.26; 95% CI, 1.04–1.52; P = 0.016). In a subgroup analysis by ethnicity, evidence of significant association between PPARG c.1347C>T polymorphism and cancer risk was found among Asians and mixed populations. In a subgroup analysis by cancer type, PPARG c.1347C>T polymorphism was associated with risk of esophageal cancer and glioblastoma. In addition, in a subgroup analysis by origin of cancer cell, evidence of significant association between PPARG c.1347C>T polymorphism and cancer risk was also found among epithelial tumor. In conclusion, the findings indicate PPARG c.1347C>T polymorphism may increase the susceptibility of cancer.

A novel variant on chromosome 6p21.1 is associated with the risk of developing colorectal cancer: a two-stage case-control study in Han Chinese

BACKGROUND

Genes in inflammatory pathways play a pivotal role in the development of colorectal cancer. We conducted a two-stage case-control study and aimed at screening the colorectal cancer-associated genetic variations in inflammatory genes.

METHODS

Twenty-three candidate variants were genotyped in 952 primary colorectal cancer cases and 875 cancer-free controls from eastern China. Promising single nucleotide polymorphisms were further genotyped in 518 cases and 554 controls from middle China. Expression quantitative trait loci and differential gene expression analyses were performed for the associated gene.

RESULTS

rs2282151 presented consistently significant associations with the risk of colorectal cancer in both stages (odds ratio (95 % confidence interval) = 1.30 (1.16-1.46), risk allele = C, P _combined = 8.9E-6). Gene expression quantitative trait loci analyzes uncovered consistent cis-regulatory signals which showed that the C allele of rs2282151 was associated with increased expression level of heat shock protein 90 alpha family class B member 1 (HSP90AB1). Then we found that the mRNA expression levels of HSP90AB1 were significantly higher in tumor tissues than normal tissues (fold-change = 1.83) in 28 pairs of colorectal tissue samples. The expression difference was consistent with data from online datasets. Additionally, we observed notable peaks of H3K27ac and H3K4me3 near the first intron of HSP90AB1 using ChIP-seq data from multiple cell lines (including HCT116).

CONCLUSIONS

Our findings indicate that the C allele of the novel colorectal cancer-associated variant rs2282151 is associated with increased expression levels of HSP90AB1, which is expressed higher in colorectal tumor tissues than in normal tissues.

The association of three promoter polymorphisms in interleukin-10 gene with the risk for colorectal cancer and hepatocellular carcinoma: A meta-analysis

Mounting evidence supports a potent inhibitory role of interleukin-10 (IL-10) in tumor carcinogenesis, angiogenesis and metastasis. This meta-analysis was designed to examine the association of three promoter polymorphisms (−592C > A, −819C > T and −1082G > A) in IL-10 gene with the risk for colorectal cancer and hepatocellular carcinoma. Qualification assessment and data collection were completed by two authors independently. The random-effects model using the DerSimonian and Laird method was fitted by the STATA software. Twenty-five articles involving 5933 cases and 9724 controls were meta-analyzed. Overall comparisons of the mutant alleles (−592A, −819T and −1082A) of three promoter polymorphisms with alternative wild alleles failed to reveal any statistical significance for both colorectal cancer and hepatocellular carcinoma (P > 0.05), and the likelihood of heterogeneity was low (I² < 50%). For −592C > A polymorphism, a significant risk for colorectal cancer was identified when analysis was restricted to East Asians (odds ratio or OR = 1.41, 95% confidence interval or CI: 1.18–1.68, P < 0.001) and retrospective studies (OR = 1.23, 95% CI: 1.09–1.39, P = 0.001). As weighed by the Egger’s test and the fill-and-trim method, there was a low probability of publication bias for all studied polymorphisms. Our findings collectively suggest that the −592C > A polymorphism in IL-10 gene might be a susceptibility locus for colorectal cancer in East Asians.

Polymorphisms in ATP-binding cassette transporter genes and interaction with diet and life style factors in relation to colorectal cancer in a Danish prospective case-cohort study

BACKGROUND AND AIMS

The ATP-binding cassette (ABC) transporter family transports various molecules across the enterocytes in the gut protecting the intestine against potentially harmful substances. Moreover, ABC transporters are involved in mucosal immune defence through interaction with cytokines. The study aimed to assess whether polymorphisms in ABCB1, ABCC2 and ABCG2 were associated with risk of colorectal cancer (CRC) and to investigate gene-environment (dietary factors, smoking and use of non-steroidal anti-inflammatory drugs) and gene-gene interactions between previously studied polymorphisms in IL1B and IL10 and ABC transporter genes in relation to CRC risk.

MATERIALS AND METHODS

We used a Danish prospective case-cohort study of 1010 CRC cases and 1829 randomly selected participants from the Danish Diet, Cancer and Health cohort. Incidence rate ratios were calculated based on Cox' proportional hazards model.

RESULTS

None of the polymorphisms were associated with CRC, but ABCB1 and ABCG2 haplotypes were associated with risk of CRC. ABCB1/rs1045642 interacted with intake of cereals and fiber (p-Value for interaction (P(int)) = 0.001 and 0.01, respectively). In a three-way analysis, both ABCB1/rs1045642 and ABCG2/rs2231137 in combination with IL10/rs3024505 interacted with fiber intake in relation to risk of CRC (P(int) = 0.0007 and 0.009).

CONCLUSIONS

Our results suggest that the ABC transporters P-glycoprotein/multidrug resistance 1 and BRCP, in cooperation with IL-10, are involved in the biological mechanism underlying the protective effect of fiber intake in relation to CRC. These results should be replicated in other cohorts to rule out chance findings.

Genetic variants in IL-6/JAK/STAT3 pathway and the risk of CRC

Interleukin (IL)-6 and the downstream Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway have previously been reported to be important in the development of colorectal cancer (CRC), and several studies have shown the relationship between the polymorphisms of related genes in this pathway with the risk of CRC. However, the findings of these related studies are inconsistent. Moreover, there has no systematic review and meta-analysis to evaluate the relationship between genetic variants in IL-6/JAK/STAT3 pathway and CRC susceptibility. Hence, we conducted a meta-analysis to explore the relationship between polymorphisms in IL-6/JAK/STAT3 pathway genes and CRC risk. Eighteen eligible studies with a total of 13,795 CRC cases and 18,043 controls were identified by searching PubMed, Web of Science, Embase, and the Cochrane Library databases for the period up to September 15, 2015. Odds ratios (ORs) and their 95 % confidence intervals (CIs) were used to calculate the strength of the association. Our results indicated that IL-6 genetic variants in allele additive model (OR = 1.05, 95 % CI = 1.00, 1.09) and JAK2 genetic variants (OR = 1.40, 95 % CI = 1.15, 1.65) in genotype recessive model were significantly associated with CRC risk. Moreover, the pooled data revealed that IL-6 rs1800795 polymorphism significantly increased the risk of CRC in allele additive model in Europe (OR = 1.07, 95 % CI = 1.01, 1.14). In conclusion, the present findings indicate that IL-6 and JAK2 genetic variants are associated with the increased risk of CRC while STAT3 genetic variants not. We need more well-designed clinical studies covering more countries and population to definitively establish the association between genetic variants in IL-6/JAK/STAT3 pathway and CRC susceptibility.

Circulating interleukin-6 and cancer: A meta-analysis using Mendelian randomization

Interleukin-6 (IL-6) plays a contributory role in the progression and severity of many forms of cancer; it however remains unclear whether the relevance between circulating IL-6 and cancer is causal. We therefore meta-analyzed published articles in this regard using IL-6 gene -174G/C variant as an instrument. Seventy-eight and six articles were eligible for the association of -174G/C variant with cancer and circulating IL-6, respectively. Overall analyses failed to identify any significance between -174G/C and cancer risk. In Asians, carriers of the -174CC genotype had an 1.95-fold increased cancer risk compared with the -174GG genotype carriers (P = 0.009). By cancer type, significance was only attained for liver cancer with the -174C allele conferring a reduced risk under allelic (odds ratio or OR = 0.74; P = 0.001), homozygous genotypic (OR = 0.59; P = 0.029) and dominant (OR = 0.67; P = 0.004) models. Carriers of the -174CC genotype (weighted mean difference or WMD = −4.23 pg/mL; P < 0.001) and -174C allele (WMD = −3.43 pg/mL; P < 0.001) had circulating IL-6 reduced significantly compared with the non-carriers. In further Mendelian randomization analysis, a reduction of 1 pg/mL in circulating IL-6 was significantly associated with an 12% reduced risk of liver cancer. Long-term genetically-reduced circulating IL-6 might be causally associated with a lower risk of liver cancer.

Effect of Proliferator-Activated Receptor-γ Pro12Ala Polymorphism on Colorectal Cancer Risk: A Meta-Analysis

Background

The association between peroxisome proliferators-activated receptor γ (PPARγ) Pro12Ala polymorphism and colorectal cancer (CRC) risk is still controversial. A meta-analysis was performed.

Material/Methods

We conducted a literature search using PubMed, EMBASE, and Cochran databases. The pooled odds ratio (OR) with 95% confidence intervals (CIs) were calculated. Fixed-effects and random-effects models were used. Dominant model, recessive model, and additive model were used in this meta-analysis.

Results

Fifteen studies including 13575 cases and 17085 controls were included in our meta-analysis. Result of this meta-analysis found that PPARγ Pro12Ala polymorphism was significantly associated with a reduced risk of CRC (OR=0.90; 95% CI 0.83–0.98; P=0.01). No significant association was found between PPARγ Pro12Ala polymorphism and CRC risk in Asians (OR=0.80; 95% CI 0.60–1.09; P=0.15). However, PPARγ Pro12Ala polymorphism was significantly associated with a reduced risk of CRC in Caucasians (OR=0.91; 95% CI 0.83–0.99; P=0.03). When stratified analysis was performed by CRC site, no positive association was found between PPARγ Pro12Ala polymorphism and rectal cancer (OR=0.95; 95% CI 0.74–1.22; P=0.71). However, a reduced risk of colon cancer was observed (OR=0.85; 95% CI 0.76–0.94; P=0.002).

Conclusions

In summary, this study suggests that PPARγ Pro12Ala polymorphism was a protective factor of CRC.

Polymorphisms in NFKB1 and TLR4 and interaction with dietary and life style factors in relation to colorectal cancer in a Danish prospective case-cohort study

Maintenance of a balance between commensal bacteria and the mucosal immune system is crucial and intestinal dysbiosis may be a key event in the pathogenesis of colorectal cancer (CRC). The toll-like receptor 4 (TLR4) is an important pattern-recognition receptor that regulates inflammation and barrier function in the gut by a mechanism that involves activation of the nuclear factor-κB (NF-κB) transcription factor. Dietary and life style factors may impact these functions. We therefore used a Danish prospective case-cohort study of 1010 CRC cases and 1829 randomly selected participants from the Danish Diet, Cancer and Health cohort to investigate three polymorphisms in NFKB1 and TLR4 and their possible interactions with diet and life style factors in relation to risk of CRC. Homozygous carriage of the variant allele of the TLR4/rs5030728 polymorphism was associated with increased risk of CRC (incidence rate ratio (IRR) = 1.30; 95% confidence interval (CI): 1.05-1.60; P = 0.02 (gene-dose model); IRR = 1.24; 95%CI: 1.01-1.51; P = 0.04 (recessive model)). Del-carriers of the NFKB1/rs28362491 polymorphism had a 17% (95%CI: 1.03-1.34; P = 0.02) increased risk of CRC compared to homozygous carriers of the ins-allele. However, none of these risk estimates withstood adjustment for multiple comparisons. We found no strong gene-environment interactions between the examined polymorphism and diet and life style factors in relation to CRC risk.

Association of Nonsteroidal Anti-Inflammatory Drugs with Colorectal Cancer by Subgroups in the VITamins and Lifestyle (VITAL) Study

BACKGROUND

There is substantial evidence that use of NSAIDs reduces the risk of colorectal cancer, but no subgroup has been identified for which the chemoprevention effect outweighs the risk of side effects.

METHODS

We tested the interaction between NSAID use and multiple risk factors on colorectal cancer risk in the VITAL cohort. A total of 73,458 individuals ages 50 to 76 years completed a questionnaire between 2000 and 2002, and 674 incidental colorectal cancer cases were identified through 2010.

RESULTS

In stratified analysis, high use of any type of NSAIDs (4+ days/week for 4+ years) was statistically significantly associated with a lower risk of colorectal cancer across all subgroups stratified by sex, body mass index, physical activity, smoking, alcohol intake, screening, and dietary factors. There was a suggestion of stronger associations among men, obese individuals, and heavier drinkers; however, none of these tests for interaction reached statistical significance. The associations were almost identical for subjects with higher overall colorectal cancer risk scores [HR, 0.62; 95% confidence interval (CI), 0.49-0.79] and those with lower risk scores (HR, 0.61; 95% CI, 0.42-0.88). Differential effects by cancer subsites and stages were tested. NSAID use was associated with a greater risk reduction of proximal colon cancer versus distal (P for difference = 0.06) and distant stage versus local (P for difference = 0.04).

CONCLUSION

The association between high use of NSAIDs and colorectal cancer risk does not differ significantly among subgroups.

IMPACT

Our results suggest that NSAIDs have a generally beneficial role in colorectal cancer prevention, largely unmodified by other exposures.

Gene-diet interactions and their impact on colorectal cancer risk

A number of studies have evaluated the role of gene-diet interaction in the etiology of colorectal cancer (CRC). Historically, these studies focused on established dietary risk factors and genes involved in their metabolism. However, results from these candidate gene studies were inconsistent, possibly due to multiple testing and publication bias. In recent years, genome-wide association studies have identified a number of CRC susceptibility loci, and subsequent meta-analyses have observed limited evidence that diet may modify the risk associated with these susceptibility loci. Statistical techniques have been recently developed to evaluate the presence of interaction across the entire genome; results from these genome-wide studies have demonstrated limited evidence of interaction and have failed to replicate results from candidate gene studies and those using established susceptibility loci. However, larger sample sizes are likely needed to elucidate modest or weak interaction in genome-wide studies of gene-diet interaction.

Interactions between meat intake and genetic variation in relation to colorectal cancer

Meat intake is associated with the risk of colorectal cancer. The objective of this systematic review was to evaluate interactions between meat intake and genetic variation in order to identify biological pathways involved in meat carcinogenesis. We performed a literature search of PubMed and Embase using “interaction”, “meat”, “polymorphisms”, and “colorectal cancer”, and data on meat–gene interactions were extracted. The studies were divided according to whether information on meat intake was collected prospectively or retrospectively. In prospective studies, interactions between meat intake and polymorphisms in PTGS2 (encoding COX-2), ABCB1, IL10, NFKB1, MSH3, XPC (P_int = 0.006, 0.01, 0.04, 0.03, 0.002, 0.01, respectively), but not IL1B, HMOX1, ABCC2, ABCG2, NR1I2 (encoding PXR), NR1H2 (encoding LXR), NAT1, NAT2, MSH6, or MLH1 in relation to CRC were found. Interaction between a polymorphism in XPC and meat was found in one prospective and one case–control study; however, the directions of the risk estimates were opposite. Thus, none of the findings were replicated. The results from this systematic review suggest that genetic variation in the inflammatory response and DNA repair pathway is involved in meat-related colorectal carcinogenesis, whereas no support for the involvement of heme and iron from meat or cooking mutagens was found. Further studies assessing interactions between meat intake and genetic variation in relation to CRC in large well-characterised prospective cohorts with relevant meat exposure are warranted.

Systematic review: interactions between aspirin, and other nonsteroidal anti-inflammatory drugs, and polymorphisms in relation to colorectal cancer

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) include aspirin (acetylsalicylic acid, ASA). Long-term use of NSAIDs has been associated with lowered risk of colorectal cancer (CRC), but the use is hampered by adverse effects. Also, the anti-carcinogenic effects of NSAIDs are incompletely understood. Understanding biological effects of NSAIDs may help developing new preventive medical strategies.

AIM

To identify gene-environment interactions between genetic variation and NSAID use in relation to risk of CRC.

METHODS

We performed a PubMed literature search and all studies reporting original data on interactions between NSAIDs and polymorphisms in relation to CRC were evaluated.

RESULTS

We found indications that aspirin interacted with rs6983267 close to MYC (encoding a transcription factor involved in cell cycle progression, apoptosis and cellular transformation) and NSAIDs interacted with rs3024505 and rs1800872 in or close to IL10 (encoding IL-10) in preventing CRC. Homozygous carriers of the variant allele of rs6983267 (ca. 25% of the population) halved their risk for CRC by aspirin use compared to homozygous wildtype carriers who did not benefit from aspirin intake. No interaction between use of NSAIDs and PTGS-2 (encoding COX-2) in relation to CRC risk was detected. Other findings of interactions between genes in inflammatory and oncogenic pathways and NSAIDs were considered suggestive.

CONCLUSIONS

Knowledge of underlying biological effects of NSAIDs in relation to CRC is scarce and the basis for stratifying the patients for preventive treatment is not yet available. Further studies assessing interactions between long-term NSAID exposure and genetic variation in relation to CRC are warranted in large well-characterised prospective cohorts.

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.

NOD2 polymorphisms associated with cancer risk: a meta-analysis

BACKGROUND

Emerging evidence indicated that common polymorphisms of NOD2 might impact individual susceptibility to cancer. However, the results from published studies were inconclusive. The aim of this meta-analysis was to elucidate whether NOD2 polymorphisms were associated with cancer risk.

METHODS

A systematically literature search was performed by using electronic databases including PubMed and Web of Science. ORs and their 95% CI were used to assess the strength of association between NOD2 gene polymorphisms and cancer risks.

RESULTS

Thirty case-control studies were included in this meta-analysis. The pooled analysis indicated that NOD2 rs2066842 C/T polymorphism was not significantly associated with cancer risk; for NOD2 rs2066844 C/T polymorphism, (TT+CT) genotype was associated with increased cancer risk compared with wild-type CC genotype (OR = 1.32, 95% CI = 1.01-1.72, P = 0.041); for NOD2 rs2066845 C/G polymorphism, individuals with (CC+CG) genotype were significantly associated with increased cancer risk compared with GG genotype (OR = 1.32, 95% CI = 1.01-1.72, P = 0.040); for NOD2 rs2066847 (3020insC) polymorphism, carriers of (insC/insC+insC/-) genotype were significantly associated with increased cancer risk compared with -/- carriers (OR = 1.23, 95% CI = 1.10-1.38, P<0.001). In the subgroup analysis of cancer type, (insC/insC+insC/-) genotype was significantly associated with increased risk of colorectal cancer, gastric cancer and MALT lymphoma, breast cancer, lung cancer, laryngeal cancer but not with urogenital cancer, pancreatic cancer, melanoma or non-Hodgkin lymphoma.

CONCLUSION

NOD2 rs2066844 C/T, rs2066845 C/G and rs2066847 (3020insC) polymorphisms might be associated with increased cancer risk. No significant association was observed between NOD2 rs2066842 C/T polymorphism and cancer risk. Further large-scale and well-designed studies are still needed to confirm the results of our meta-analysis.

Association between six genetic polymorphisms and colorectal cancer: a meta-analysis

OBJECTIVE

The aim of this study was to determine whether six genetic polymorphisms confer susceptibility to colorectal cancer (CRC).

METHODS

A systematic search for candidate genes of CRC was performed among several online databases, including PubMed, Embase, Web of Science, the Cochrane Library, CNKI, and Wanfang online libraries. After a comprehensive filtering procedure, we harvested five genes, including MGMT (rs12917 and rs2308321), ADH1B (rs1229984), SOD2 (rs4880), XPC (rs2228001), and PPARG (rs1801282). Using the REVMAN and Stata software, six meta-analyses were conducted for associations between CRC and the just-mentioned genetic variants.

RESULTS

A total of 34 comparative studies among 17,289 cases and 54,927 controls were involved in our meta-analyses. Significant association was found between ADH1B rs1229984 polymorphism and CRC (p=0.03, odds ratio [OR]=1.18, 95% confidence interval [CI]=1.01-1.36). We also found significant association between PPARG rs1801282 polymorphism and CRC (p=0.004, OR=1.498, 95% CI=1.139-1.970), and this significant association is specific in Caucasians (p=0.004, OR=1.603, 95% CI=1.165-2.205).

CONCLUSIONS

The current meta-analysis has established that ADH1B (rs1229984) and PPARG (rs1801282) are two risk variants of CRC.

The interleukin 10 -819C/T polymorphism and cancer risk: a HuGE review and meta-analysis of 73 studies including 15,942 cases and 22,336 controls

The aim of the present work was to perform a meta-analysis to evaluate the association between the interleukin 10 (IL-10) -819C/T (rs1800871) polymorphism and cancer risk. A total of 73 studies, including 15,942 cancer cases and 22,336 controls, were identified in this meta-analysis. The odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using the random-effects model. Overall, no significant association was identified between the IL-10 -819C/T polymorphism and cancer risk. In the subgroup analyses, the T allele and TT genotype were associated with a moderately reduced cancer risk in the Asian population (T allele vs. C allele: OR=0.93, 95%CI: 0.87, 0.99; TT vs. CC: OR=0.86, 95%CI: 0.76, 0.98; TT vs. CT/CC: OR=0.90, 95%CI: 0.82, 0.98). Individuals who were homozygous for the T allele (TT) were found to be associated with significantly reduced gastric cancer risk in the Asian population. The heterozygous variant (CT) and the dominant model (TT/CT vs. CC) were associated with an increased risk for cervical and ovarian cancer. However, the IL-10 -819C/T polymorphism was not significantly associated with breast cancer, colorectal cancer, lung cancer, hepatocellular carcinoma, prostate cancer, lymphoma, or melanoma. The depressed cancer risk of the TT genotype occurred in the studies of hospital-based case-control studies and the studies recruited less than 500 subjects, but no statistically significant results were found in the stratified analyses using genotyping method. The results suggest that the IL-10 -819TT genotype may be a protective factor for cancer in Asians, especially gastric cancer. In contrast, the CT genotype and the dominant model could be risk factors for cervical and ovarian cancer. The importance of stratifying by ethnicity, cancer type, study design, and sample size needs to be standardized in future studies, together with considering the association between the IL-10 -819C/T polymorphism and cancer risk. Furthermore, the linkage of -819C/T with other polymorphisms of the IL-10 gene may help explain the variability in findings.

Interactions between diet, lifestyle and IL10, IL1B, and PTGS2/COX-2 gene polymorphisms in relation to risk of colorectal cancer in a prospective Danish case-cohort study

Background & Aims

Diet contributes to colorectal cancer development and may be potentially modified. We wanted to identify the biological mechanisms underlying colorectal carcinogenesis by assessment of diet-gene interactions.

Methods

The polymorphisms IL10 C-592A (rs1800872), C-rs3024505-T, IL1b C-3737T (rs4848306), G-1464C (rs1143623), T-31C (rs1143627) and PTGS2 (encoding COX-2) A-1195G (rs689466), G-765C (rs20417), and T8473C (rs5275) were assessed in relation to risk of colorectal cancer (CRC) and interaction with diet (red meat, fish, fibre, cereals, fruit and vegetables) and lifestyle (non-steroid-anti-inflammatory drug use and smoking status) was assessed in a nested case-cohort study of nine hundred and seventy CRC cases and 1789 randomly selected participants from a prospective study of 57,053 persons.

Results

IL1b C-3737T, G-1464C and PTGS2 T8473C variant genotypes were associated with risk of CRC compared to the homozygous wildtype genotype (IRR=0.81, 95%CI: 0.68-0.97, p=0.02, and IRR=1.22, 95%CI: 1.04-1.44, p=0.02, IRR=0.75, 95%CI: 0.57-0.99, p=0.04, respectively). Interactions were found between diet and IL10 rs3024505 (P-value for interaction (P_int); meat=0.04, fish=0.007, fibre=0.0008, vegetables=0.0005), C-592A (P_int; fibre=0.025), IL1b C-3737T (P_int; vegetables=0.030, NSAID use=0.040) and PTGS2 genotypes G-765C (P_int; meat=0.006, fibre=0.0003, fruit 0.004), and T8473C (P_int; meat 0.049, fruit=0.03) and A-1195G (P_int; meat 0.038, fibre 0.040, fruit=0.059, vegetables=0.025, and current smoking=0.046).

Conclusions

Genetically determined low COX-2 and high IL-1β activity were associated with increased risk of CRC in this northern Caucasian cohort. Furthermore, interactions were found between IL10, IL1b, and PTGS2 and diet and lifestyle factors in relation to CRC. The present study demonstrates that gene-environment interactions may identify genes and environmental factors involved in colorectal carcinogenesis.

Innate immunity gene polymorphisms and the risk of colorectal neoplasia

Inherited variation in genes that regulate innate immunity and inflammation may contribute to colorectal neoplasia risk. To evaluate this association, we conducted a nested case-control study of 451 colorectal cancer cases, 694 colorectal advanced adenoma cases and 696 controls of European descent within the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. A total of 935 tag single-nucleotide polymorphisms (SNPs) in 98 genes were evaluated. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association with colorectal neoplasia. Sixteen SNPs were associated with colorectal neoplasia risk at P < 0.01, but after adjustment for multiple testing, only rs2838732 (ITGB2) remained suggestively associated with colorectal neoplasia (OR(per T allele) = 0.68, 95% CI: 0.57-0.83, P = 7.7 × 10(-5), adjusted P = 0.07). ITGB2 codes for the CD18 protein in the integrin beta chain family. The ITGB2 association was stronger for colorectal cancer (OR(per T allele) = 0.41, 95% CI: 0.30-0.55, P = 2.4 × 10(-) (9)) than for adenoma (OR(per T allele) = 0.84, 95%CI: 0.69-1.03, P = 0.08), but it did not replicate in the validation study. The ITGB2 rs2838732 association was significantly modified by smoking status (P value for interaction = 0.003). Among never and former smokers, it was inversely associated with colorectal neoplasia (OR(per T allele) = 0.5, 95% CI: 0.37-0.69 and OR(per T allele) = 0.72, 95% CI: 0.54-0.95, respectively), but no association was seen among current smokers. Other notable findings were observed for SNPs in BPI/LBP and MYD88. Although the results need to be replicated, our findings suggest that genetic variation in inflammation-related genes may be related to the risk of colorectal neoplasia.

Current evidences on IL1B polymorphisms and lung cancer susceptibility: a meta-analysis

Interleukin 1, beta (IL1B) plays a key role in mediating acute and chronic inflammation, which is further correlated with lung carcinogenesis. Several polymorphisms on IL1B gene have been identified, and a series of epidemiological studies have examined the association between IL1B polymorphisms and lung cancer risk. However, these findings are inconclusive. To derive a precise estimation of the relationship, a meta-analysis was performed. We summarized 12 eligible publications on three commonly studied IL1B polymorphisms (i.e., -31 T/C, -511 T/C, and +3954 C/T) by searching electronic databases. Combined odds ratio (OR) with 95% confidence interval (CI) was calculated to assess the strength of association between them. Heterogeneity and publication bias were also assessed. We observed a significant association between IL1B polymorphisms and lung cancer. For -31T/C, the overall OR (95% CI) of TT/TC versus CC was 1.23 (1.06-1.43). For +3954 C/T, the overall OR (95% CI) of CC versus TT and CC versus CT/TT were 0.92 (0.86-0.99) and 0.92 (0.86-0.99), respectively. In conclusion, this meta-analysis suggests that the IL1B -31 T/C and +3954 C/T polymorphisms are associated with lung cancer risk. However, larger number of samples and studies with homogeneous lung cancer patients are needed to confirm these findings.

Lack of association between interleukin-8-251 T>A polymorphism and colorectal cancer risk: a meta-analysis based on 3,019 cases and 3,984 controls

PURPOSE

The results of recent published studies focusing on IL-8 polymorphism in colorectal cancer susceptibility have often been inconsistent. We therefore carried out a meta-analysis based on independent studies to assess the association.

METHODS

Nine case-control studies with 7,003 individuals (3,019 cases and 3,984 controls) were included in this meta-analysis through searching the databases of PubMed, Excerpta Medica Database (EMBASE), and Chinese Biomedical Literature Database (CBM; Chinese) (up to Aug 1st, 2012). The odds ratio (OR) and 95% confidence interval (95%CI) were used to assess the strength of the association. Meta-analysis was conducted in a fixed/random effect model.

RESULTS

No obvious associations were found for all genetic models when all studies were pooled into the meta-analysis (for A vs. T: OR = 1.084, 95% CI = 0.971- 1.209, P = 0.019; for TA vs. TT: OR = 1.18, 95% CI = 0.943-1.475, P = 0.001; for AA vs. TT: OR = 1.155, 95% CI = 0.916-1.456, P = 0.014; for AA+TA vs. TT: OR = 1.170, 95% CI =0.953-1.437, P = 0.001; for AA vs. TT+TA: OR = 1.044, 95% CI = 0.886-1.230, P = 0.097). In the subgroup analyses by ethnicity (Caucasian) and source of controls (population based), also no significant associations were found for all genetic models.

CONCLUSIONS

Result suggests that the IL-8-251T>A polymorphism is not associated with colorectal cancer risk. Because of the limitations of this meta-analysis, this finding demands further investigation.

Systematic review: diet-gene interactions and the risk of colorectal cancer

BACKGROUND

Diet contributes significantly to colorectal cancer (CRC) aetiology and may be potentially modifiable.

AIM

To review diet-gene interactions, aiming to further the understanding of the underlying biological pathways in CRC development.

METHODS

The PubMed and Medline were systematically searched for prospective studies in relation to diet, colorectal cancer and genetics.

RESULTS

In a meta-analysis, no interaction between NAT1 phenotypes and meat intake in relation to risk of CRC was found (P-value for interaction 0.95). We found a trend towards interaction between NAT2 phenotypes and meat intake in relation to risk of CRC. High meat intake was not associated with risk of CRC among carriers of the slow NAT2 phenotype, whereas NAT2 fast acetylators with high meat intake were at increased risk of CRC (OR = 1.25; 95% confidence interval (CI): 0.92-2.01) compared with slow acetylators with low meat intake (reference), P-value for interaction = 0.07. Low meat intake in the studied populations may influence the result. Interactions between meat, cruciferous vegetables, fibres, calcium, vitamins, and alcohol and ABCB1, NFKB1, GSTM1, GSTT1, CCND1, VDR, MGTM, IL10 and PPARG are suggested.

CONCLUSIONS

A number of interactions between genetic variation and diet are suggested, but the findings need replication in independent, prospective, and well-characterised cohorts before conclusions regarding the underlying biological mechanisms can be reached. When the above criteria are met, studies on diet-gene interactions may contribute valuable insight into the biological mechanisms underlying the role of various dietary items in colorectal carcinogenesis.

Meta-analysis of epidemiological studies of association of two polymorphisms in the interleukin-10 gene promoter and colorectal cancer risk

In order to make a comprehensive assessment of the potential association between two genetic variants in the IL-10 gene promoter, -1082 A>G (rs1800896) and -592 C>A (rs1800872), and colorectal cancer (CRC) risk, we conduced a meta-analysis of seven epidemiological studies, which included 1469 colorectal cancer cases and 2566 controls. Neither of the two polymorphisms had any association with increased CRC risk in overall population [for rs1800896: odds ratio (OR) = 0.90, 95% confidence interval (95%CI) = 0.76-1.06 in the dominant model and for rs1800872: OR = 1.06, 95%CI = 0.91-1.23 in the dominant model]. In subgroup analysis of the rs1800896 polymorphism, the results did not change when the analyses were restricted to individual studies, or those fulfilling Hardy-Weinberg equilibrium, or according to the source of controls. For rs1800872, however, when stratifying by the source of controls, the A allele had a significant increased risk of CRC among studies with population-based controls in the codominant model (AC vs CC: OR = 1.30, 95%CI = 1.04-1.63) and dominant model (AA/AC vs CC: OR = 1.25, 95% CI = 1.01-1.55). Based on this meta-analysis, we conclude that the IL-10 rs1800872 polymorphism could be a risk factor for CRC development among European populations. However, we found no association between the IL-10 rs1800896 polymorphism and CRC risk. Further studies, either with larger sample size or involving other SNPs and haplotypes of the IL-10 gene, are necessary to clarify the contribution of IL-10 genetic variations in colorectal carcinogenesis.

Single nucleotide polymorphisms in IL1B and the risk of acute coronary syndrome: a Danish case-cohort study

Background

Interleukin-1B (IL-1B) is a key pro-inflammatory cytokine that has been associated with the development of atherosclerosis and myocardial infarction. However, the prospective associations between functional single nucleotide polymorphisms (SNPs) in IL1B and incident acute coronary syndrome (ACS) have not been thoroughly investigated. The aims of this study were to examine the associations between individual SNPs in and SNP haplotypes of the promoter region of IL1B and incident ACS in a prospective study. Furthermore, we wanted to explore potential interactions with other risk factors for ACS on an additive scale.

Methodology/Principal Findings

The present study was based on the Danish prospective study Diet, Cancer and Health comprising more than 57 000 participants aged 50–64 at baseline. During a median follow-up of 7.2 years we identified 989 cases of incident ACS (755 men and 234 women). All cases were validated by review of medical records, and information on covariates was collected by study technicians. The study was conducted according to a case-cohort study design including ACS cases and a sex-stratified sub cohort of 1663 participants drawn randomly from the entire cohort. Weighted Cox proportional hazard models with age as time axis were used in the statistical analyses. Individual IL1B SNPs, SNP haplotypes, or haplotype combinations were not significantly associated with incident ACS, and, likewise, we found no evidence of interaction on an additive scale between IL1B haplotypes and risk factors, respectively.

Conclusions/Significance

Genetic variation in the promoter region of IL1B may not be associated with incident ACS in men or women above the age of 50 years.

Interaction between interleukin-10 (IL-10) polymorphisms and dietary fibre in relation to risk of colorectal cancer in a Danish case-cohort study

Background

More than 50% of the colorectal cancer (CRC) etiology has been attributed to diet. Established or suspected dietary factors modifying risk of CRC are red meat, cereals, fish, and fibre. Diet and lifestyle may be linked to cancer through inflammation. Interleukin-10 (IL-10) is an anti-inflammatory cytokine. We wanted to test if dietary factors and IL10 polymorphisms interact in relation to colorectal carcinogenesis.

Methods

The functional IL10 polymorphism C-592A (rs1800872) and the marker rs3024505 were assessed in relation to diet and lifestyle in a nested case-cohort study of 378 CRC cases and 775 randomly selected participants from a prospective study of 57,053 persons. Genotyping data on the IL10 polymorphism C-592A, smoking and non-steroidal anti-inflammatory drugs (NSAID) was retrieved from Vogel et al. (Mutat Res, 2007; 624:88). Incidence rate ratios (IRR) and 95% Confidence Interval (95% CI) were calculated.

Results

No associations were found between the IL10 rs3024505 polymorphism and risk of CRC. There was interaction between rs3024505 and dietary fibre (P-value for interaction = 0.01). IL10 rs3024505 homozygous wildtype carriers were at 27% reduced risk of CRC per 10 g fibre per day (95% CI: 0.60-0.88) whereas variant carriers had no risk reduction by fibre intake. Also, interaction between IL10 C-592A and intake of fibre was found (P-value for interaction = 0.02). Among those eating <17.0 grams of fibre per day, carriers of an C-592A variant allele had a statistically significantly higher risk of colorectal cancer compared to homozygous wildtypes. No significant differences in colorectal cancer risk were observed between the reference group (CC and <17.0 g/day) and carriers of one C-592A variant allele eating 17.0 or more grams of dietary fibre per day. This suggests that the increased risk due to carrying the variant allele can be overcome by higher fibre intake. No interactions between IL10 polymorphisms and dietary meat, cereal, or fish intake, or between IL10 rs3024505 and smoking or NSAID use were found.

Conclusions

In this northern Caucasian cohort we found interaction between IL10 and dietary fibre in CRC carcinogenesis. High intake of fibre seems to protect against CRC among individuals with IL10 related genetic susceptibility to CRC. This finding should be evaluated in other prospective and population-based cohorts with different ethnic groups.

A functional polymorphism in the promoter region of the IL1B gene is associated with risk of multiple myeloma

The cytokine interleukin-1β (IL1B) is important for anti-tumour immune response. Genetic variation may modify the expression of IL1B and thereby influence the risk of disease. We investigated genetic variations with functional importance in the IL1B and NFKB1 genes in 348 population-based samples of multiple myeloma (MM) and a random sample of 1700 individuals. Carriers of the variant T-allele IL1B C-3737T and carriers of the TGT haplotype were at lower risk of MM [relative risk (RR) 0·58 (95% confidence interval (CI) = 0·41-0·84) and RR 0·59 (95%CI 0·40-0·85), respectively]. No association with risk of MM was found for the NFKB1- 94 ins/del polymorphism.

PPARgamma-PGC-1alpha activity is determinant of alcohol related breast cancer

Alcohol is a risk factor for postmenopausal breast cancer. One of several proposed mechanisms is that alcohol-related breast cancer is caused by increased sex hormone levels. PPARγ inhibits aromatase transcription in breast adipocytes. We reproduced previously found allele-specific effects of the wildtype Pro-allele of PPARG Pro(12)Ala in alcohol related breast cancer. In transiently transfected cells, transcriptional activation by PPARγ and the PPARγ-PGC-1α complex was inhibited by ethanol. PPARγ 12Ala-mediated transcription activation was not enhanced by PGC-1α, resulting in allele-specific transcription activation by the PPARγ 12Pro-PGC-1α complex. Our results suggest that PPARγ and PGC-1α activity is an important determinant of alcohol related breast cancer.