Polymorphisms in NFkB, PXR, LXR and risk of colorectal cancer in a prospective study of Danes

Short interfering RNA in colorectal cancer: is it wise to shoot the messenger?

Colorectal cancer (CRC) is the third most common cancer and the leading cause of gastrointestinal cancer death. 90% of people diagnosed with colorectal cancer are over the age of 50; nevertheless, the illness is more aggressive among those detected at a younger age. Chemotherapy-based treatment has several adverse effects on both normal and malignant cells. The primary signaling pathways implicated in the advancement of CRC include hedgehog (Hh), janus kinase and signal transducer and activator of transcription (JAK/STAT), Wingless-related integration site (Wnt)/β-catenin, transforming growth factor-β (TNF-β), epidermal growth factor receptor (EGFR)/Mitogen-activated protein kinases (MAPK), phosphoinositide 3-kinase (PI3K), nuclear factor kappa B (NF-κB), and Notch. Loss of heterozygosity in tumor suppressor genes like adenomatous polyposis coli, as well as mutation or deletion of genes like p53 and Kirsten rat sarcoma viral oncogene (KRAS), are all responsible for the occurrence of CRC. Novel therapeutic targets linked to these signal-transduction cascades have been identified as a consequence of advances in small interfering RNA (siRNA) treatments. This study focuses on many innovative siRNA therapies and methodologies for delivering siRNA therapeutics to the malignant site safely and effectively for the treatment of CRC. Treatment of CRC using siRNA-associated nanoparticles (NPs) may inhibit the activity of oncogenes and MDR-related genes by targeting a range of signaling mechanisms. This study summarizes several siRNAs targeting signaling molecules, as well as the therapeutic approaches that might be employed to treat CRC in the future.

The ATP-binding cassette proteins ABCB1 and ABCC1 as modulators of glucocorticoid action

Responses to hormones that act through nuclear receptors are controlled by modulating hormone concentrations not only in the circulation but also within target tissues. The role of enzymes that amplify or reduce local hormone concentrations is well established for glucocorticoid and other lipophilic hormones; moreover, transmembrane transporters have proven critical in determining tissue responses to thyroid hormones. However, there has been less consideration of the role of transmembrane transport for steroid hormones. ATP-binding cassette (ABC) proteins were first shown to influence the accumulation of glucocorticoids in cells almost three decades ago, but observations over the past 10 years suggest that differential transport propensities of both exogenous and endogenous glucocorticoids by ABCB1 and ABCC1 transporters provide a mechanism whereby different tissues are preferentially sensitive to different steroids. This Review summarizes this evidence and the new insights provided for the physiology and pharmacology of glucocorticoid action, including new approaches to glucocorticoid replacement.

NF-қB and COX-2 Relation Between Endometrial Cancer and the Clinicopathological Parameters

Objective: Our study examines nuclear factor kappa B (NF-қB) and cyclooxygenase-2 (COX-2) polymorphisms in the most common gynecological cancer type, endometrial cancer, and the relationship between disease parameters and these polymorphisms. Methods: In our patient group; while 109 endometrial cancer patients were examined and treated in the Department of Gynecology and Obstetrics, Istanbul Medical Faculty, and 106 healthy women without the disease were included in the control group. DNA of blood samples taken from all groups were isolated; COX-2 765C> G and COX-2 1195A> G polymorphisms were studied with NF-қB-94 ins / delATTG. Genotypes analyzed using the PCR-based restriction fragment length polymorphisms (RFLP) method were investigated in terms of the relationship between endometrial cancer susceptibility and endometrial cancer disease parameters. Results in SPSS 17 program; Student’s t-tests were analyzed using Anova, Fisher’s exact, and Chi-square tests. Results: NF-қB D + and DD genotype, COX-2 765 G + and GG genotype, and COX-2 1195 AA genotype were found to be significantly more common in the endometrial cancer group compared to the control group (p

Diet derived polycyclic aromatic hydrocarbons and its pathogenic roles in colorectal carcinogenesis

Polycyclic aromatic hydrocarbon (PAHs) are molecules that contaminate meat products during the high-temperature cooking of meat. This study reviewed the pathogenic roles of meat derived polycyclic aromatic hydrocarbons in the carcinogenesis of colorectal cancer (CRC). Ingested PAHs undergo xenobiotic metabolism resulting in the activation of genotoxic metabolites that can induce DNA damage in the colorectum. Genetic polymorphisms in PAH xenobiotic enzymes are linked to the risk of CRC and suggest a role for PAH-meat ingestion in carcinogenesis of colorectal malignancies. Furthermore, PAH specific DNA adducts have been identified in colorectal cancer tissue and linked to high meat intake. DNA adduct resolution is mediated by the nucleotide excision repair, and polymorphisms within genes of this repair pathway and high meat intake are associated with increased CRC risk. In the literature, there is evidence from metabolic enzyme gene variants, DNA repair genes, PAH metabolites, and epidemiological studies suggesting PAH involvement in CRC.

The significant role of a functional polymorphism in the NF-κB1 gene in breast cancer: evidence from an Iranian cohort

Aims: Breast cancer (BC) is one of the most common cancers among women. The influence of genetic variations on BC risk has been thus far assessed via genome-wide association studies. NF-κB has been recognized as a major player in BC progression. In this study, the association between rs28362491 and BC was evaluated in a population from northeastern Iran. Materials & methods: This study was conducted on 476 patients with BC and 524 healthy controls. The genotyping method used was an amplification-refractory mutation system. Results: The INS/DEL genotype conferred a statistically significant increased risk in patients in comparison with controls. Additionally, in the recessive model, INS/INS + INS/DEL versus DEL/DEL was statistically significant (OR = 0.34; 95% CI: 0.12-0.96; p = 0.042). Conclusion: This study found that rs28362491, as a susceptibility genetic factor, may affect BC risk in the Iranian population.

Contributions of NFKB1 -94insertion/deletion ATTG polymorphism to the susceptibility of gastrointestinal cancers: A meta-analysis

Nuclear factor-kappa B1 (NF-κB1), a pleiotropic transcription factor, functions as a critical contributor to tumorigenesis. Growing numbers of case-control studies were carried out to analyse the potential contribution of NF-κB1 gene variants to gastrointestinal cancer risk, yet remains conflicting conclusions. Therefore, we conducted this most up-to-date meta-analysis to evaluate the relationship between NF-κB1 gene insertion (I)/deletion (D) polymorphism, namely -94ins/delATTG or rs28362491, and the susceptibility to gastrointestinal cancers. We searched PubMed, EMBASE and MEDLINE databases updated in April 2021 for relevant studies. Meta-analysis was carried out by software Stata11.0. The quantification of the relationship was determined by computing the combined odds ratios (ORs) and their corresponding 95% confidence intervals (CIs). Sensitivity analysis, the funnel plot and Begg's rank correlation test were also applied. Our findings indicate that -94ins/delATTG polymorphism could not significantly impact the susceptibility to gastrointestinal cancers. Under any five genetic models, -94ins/delATTG polymorphism was not remarkedly linked to the risk of colorectal, gastric and oesophageal cancer, respectively. The significant role of -94ins/delATTG was only observed in some certain subgroups. Findings here suggest that NF-κB1 gene -94ins/delATTG polymorphism may not predispose to gastrointestinal cancer susceptibility.

Germline Genetic Variants of Viral Entry and Innate Immunity May Influence Susceptibility to SARS-CoV-2 Infection: Toward a Polygenic Risk Score for Risk Stratification

The ongoing COVID-19 pandemic caused by the novel coronavirus, SARS-CoV-2 has affected all aspects of human society with a special focus on healthcare. Although older patients with preexisting chronic illnesses are more prone to develop severe complications, younger, healthy individuals might also exhibit serious manifestations. Previous studies directed to detect genetic susceptibility factors for earlier epidemics have provided evidence of certain protective variations. Following SARS-CoV-2 exposure, viral entry into cells followed by recognition and response by the innate immunity are key determinants of COVID-19 development. In the present review our aim was to conduct a thorough review of the literature on the role of single nucleotide polymorphisms (SNPs) as key agents affecting the viral entry of SARS-CoV-2 and innate immunity. Several SNPs within the scope of our approach were found to alter susceptibility to various bacterial and viral infections. Additionally, a multitude of studies confirmed genetic associations between the analyzed genes and autoimmune diseases, underlining the versatile immune consequences of these variants. Based on confirmed associations it is highly plausible that the SNPs affecting viral entry and innate immunity might confer altered susceptibility to SARS-CoV-2 infection and its complex clinical consequences. Anticipating several COVID-19 genomic susceptibility loci based on the ongoing genome wide association studies, our review also proposes that a well-established polygenic risk score would be able to clinically leverage the acquired knowledge.

Role of Inflammation in the Development of Colorectal Cancer

Chronic inflammation can lead to the development of many diseases, including cancer. Inflammatory bowel disease (IBD) that includes both ulcerative colitis (UC) and Crohnmp's disease (CD) are risk factors for the development of colorectal cancer (CRC). Many cytokines produced primarily by the gut immune cells either during or in response to localized inflammation in the colon and rectum are known to stimulate the complex interactions between the different cell types in the gut environment resulting in acute inflammation. Subsequently, chronic inflammation, together with genetic and epigenetic changes, have been shown to lead to the development and progression of CRC. Various cell types present in the colon, such as enterocytes, Paneth cells, goblet cells, and macrophages, express receptors for inflammatory cytokines and respond to tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), IL-6, and other cytokines. Among the several cytokines produced, TNF-α and IL-1β are the key pro-inflammatory molecules that play critical roles in the development of CRC. The current review is intended to consolidate the published findings to focus on the role of pro-inflammatory cytokines, namely TNF-α and IL-1β, on inflammation (and the altered immune response) in the gut, to better understand the development of CRC in IBD, using various experimental model systems, preclinical and clinical studies. Moreover, this review also highlights the current therapeutic strategies available (monotherapy and combination therapy) to alleviate the symptoms or treat inflammation-associated CRC by using monoclonal antibodies or aptamers to block pro-inflammatory molecules, inhibitors of tyrosine kinases in the inflammatory signaling cascade, competitive inhibitors of pro-inflammatory molecules, and the nucleic acid drugs like small activating RNAs (saRNAs) or microRNA (miRNA) mimics to activate tumor suppressor or repress oncogene/pro-inflammatory cytokine gene expression.

Exploratory Genome-Wide Interaction Analysis of Nonsteroidal Anti-inflammatory Drugs and Predicted Gene Expression on Colorectal Cancer Risk

BACKGROUND

Regular use of nonsteroidal anti-inflammatory drugs (NSAID) is associated with lower risk of colorectal cancer. Genome-wide interaction analysis on single variants (G × E) has identified several SNPs that may interact with NSAIDs to confer colorectal cancer risk, but variations in gene expression levels may also modify the effect of NSAID use. Therefore, we tested interactions between NSAID use and predicted gene expression levels in relation to colorectal cancer risk.

METHODS

Genetically predicted gene expressions were tested for interaction with NSAID use on colorectal cancer risk among 19,258 colorectal cancer cases and 18,597 controls from 21 observational studies. A Mixed Score Test for Interactions (MiSTi) approach was used to jointly assess G × E effects which are modeled via fixed interaction effects of the weighted burden within each gene set (burden) and residual G × E effects (variance). A false discovery rate (FDR) at 0.2 was applied to correct for multiple testing.

RESULTS

Among the 4,840 genes tested, genetically predicted expression levels of four genes modified the effect of any NSAID use on colorectal cancer risk, including DPP10 (PG×E = 1.96 × 10-4), KRT16 (PG×E = 2.3 × 10-4), CD14 (PG×E = 9.38 × 10-4), and CYP27A1 (PG×E = 1.44 × 10-3). There was a significant interaction between expression level of RP11-89N17 and regular use of aspirin only on colorectal cancer risk (PG×E = 3.23 × 10-5). No interactions were observed between predicted gene expression and nonaspirin NSAID use at FDR < 0.2.

CONCLUSIONS

By incorporating functional information, we discovered several novel genes that interacted with NSAID use.

IMPACT

These findings provide preliminary support that could help understand the chemopreventive mechanisms of NSAIDs on colorectal cancer.

Nuclear factor NF-κB1 functional promoter polymorphism and its expression conferring the risk of Type 2 diabetes-associated dyslipidemia

Type 2 diabetes mellitus (T2DM) accompanied by hyperlipidemia confers higher risk for diabetes as well as cardiovascular diseases. NF-κB is actively involved in generating low-grade inflammation and oxidative stress triggering the development of diabetic complications. In this study, we have attempted to investigate the association between NF-κB1 functional promoter polymorphism-94 ATTG insertion/deletion (rs28362491) with inflammatory markers in developing diabetes-linked dyslipidemia. We performed a case-control study in a total of 401 individuals belonging to three categories such as Type 2 diabetes with dyslipidemia, Type 2 diabetes without dyslipidemia, and normal healthy controls. Experiments were carried out using genotyping, real-time PCR, and western blot. Pearson's correlation, analysis of variance, and logistic regression were utilized for statistical analysis. As per genetic association conducted in this study the SNP rs28362491 showed significant allelic and genotypic associations (Allelic: OR = 1.374, CI 0.9797-1.927, p = 0.003, and Genotypic in dominant model: OR = 1.77, CI 1.04-2.99, p = 0.002) with the risk of diabetes and associated dyslipidemia. The -94 ATTG insertion/insertion (ins/ins) genotype was associated with significantly increased level of serum TNF-α (p = 0.002), serum IL-6 (p = 0.067) in diabetes-induced dyslipidemia. Multiple linear regression analysis identifies independent correlation of Total cholesterol, HDL, LDL, TNF-α, and rs28362491 ATTG ins/ins with triglyceride in diabetic dyslipidemic condition. T2DM with dyslipidemia having ins/ins genotype showed significant increased expression of pro-inflammatory cytokines such as TNF-α, IL-6, and activation of NF-κB. Our study reports that individuals with ATTG insertion allele and ATTG ins/ins genotype at NF-κB1 promoter regulatory gene predicts the risk and severity of T2DM-linked dyslipidemia.

Inherited variant in NFκB-1 promoter is associated with increased risk of IBD in an Algerian population and modulates SOX9 binding

BACKGROUND

The link between inflammation and cancer development was intensively studied in the last decade. To date, few studies explored the association between inflammatory genes and colorectal cancer (CRC) development.

AIM

The present study aimed to evaluate the implication of three single nucleotide polymorphisms (SNPs), rs28362491 ins/del -94 ATTG in NFκB1, rs6920220 (G/A) in TNFAIP3, and rs419598 (C/T) in IL1RN, which play a role in inflammation regulation in CRC development.

METHODS AND RESULTS

A case-control study was conducted on an Algerian cohort of 358 subjects (147 healthy people, 89 individuals affected by inflammatory bowel disease [IBD], and 122 CRC patients enrolled at the University Hospital Center Ben Badis of Constantine). SNPs genotyping was performed by allelic discrimination TaqMan assay. The rs28362491 ins/del heterozygous genotype in NFκB1 conferred an increased risk of IBD compared with ins/ins homozygous genotype, with an increase of twofold (OR = 2.34 [1.29-4.21]; 95% CI, 1.29-4.21, P value = 0.004). No significant association was detected for the other two variants. Dual-Luciferase Reporter Assay System performed in LoVo cells showed a significantly higher activity of the construct with ins allele of rs28362491 compared with the one harboring the del allele. Computational analysis nominated SOX9 as putative transcription factor (TF) with higher probability to bind the NFκB1 promoter at the SNP site, and we demonstrated in the in vitro assay that its overexpression modulates NFκB1 promoter activity in allele-specific manner.

CONCLUSION

We speculate that SOX9 may modulate the NFκB1 activity by binding its promoter at the SNP site in allelic specific manner.

Intake of Red and Processed Meat, Use of Non-Steroid Anti-Inflammatory Drugs, Genetic Variants and Risk of Colorectal Cancer: A Prospective Study of the Danish "Diet, Cancer and Health" Cohort

Red and processed meat have been associated with increased risk of colorectal cancer (CRC), whereas long-term use of non-steroid anti-inflammatory drugs (NSAIDs) may reduce the risk. The aim was to investigate potential interactions between meat intake, NSAID use, and gene variants in fatty acid metabolism and NSAID pathways in relation to the risk of CRC. A nested case-cohort study of 1038 CRC cases and 1857 randomly selected participants from the Danish prospective “Diet, Cancer and Health” study encompassing 57,053 persons was performed using the Cox proportional hazard model. Gene variants in SLC25A20, PRKAB1, LPCAT1, PLA2G4A, ALOX5, PTGER3, TP53, CCAT2, TCF7L2, and BCL2 were investigated. CCAT2 rs6983267 was associated with the risk of CRC per se (p < 0.01). Statistically significant interactions were found between intake of red and processed meat and CCAT2 rs6983267, TP53 rs1042522, LPCAT1 rs7737692, SLC25A20 rs7623023 (p_interaction = 0.04, 0.04, 0.02, 0.03, respectively), and the use of NSAID and alcohol intake and TP53 rs1042522 (p_interaction = 0.04, 0.04, respectively) in relation to the risk of CRC. No other consistent associations or interactions were found. This study replicated an association of CCAT2 rs6983267 with CRC and an interaction between TP53 rs1042522 and NSAID in relation to CRC. Interactions between genetic variants in fatty acid metabolism and NSAID pathways and the intake of red and processed meat were found. Our results suggest that meat intake and NSAID use affect the same carcinogenic mechanisms. All new findings should be sought replicated in independent prospective studies. Future studies on the cancer-protective effects of aspirin/NSAID should include gene and meat assessments.

Meat and fiber intake and interaction with pattern recognition receptors (TLR1, TLR2, TLR4, and TLR10) in relation to colorectal cancer in a Danish prospective, case-cohort study

Background

Meat and dietary fiber are associated with increased and decreased risk of colorectal cancer (CRC), respectively. Toll-like receptors (TLRs) regulate the intestinal immune response in a complex interplay between the mucosal epithelium and the microbiota and may therefore be important modulators of diet-induced CRC together with other inflammatory mediators.

Objective

Our aim was to investigate the association between functional TLR polymorphisms and risk of CRC and the interaction with dietary factors. Additionally, interactions with previously studied polymorphisms in IL10, IL1B, PTGS2, and NFKB1 were assessed in order to examine possible biological pathways in meat-induced CRC.

Design

A nested case-cohort study of 897 CRC cases and 1689 randomly selected participants from the Danish prospective "Diet, Cancer and Health" study encompassing 57,053 persons was performed using Cox proportional hazard models and the likelihood ratio test.

Results

We found associations between polymorphisms in TLR2 (P = 0.018) and TLR4 (P = 0.044) and risk of CRC per se, interactions between intake of red and processed meat (10 g/d) and polymorphisms in TLR1 (P-interaction = 0.032) and TLR10 (P-interaction = 0.026 and 0.036), and intake of cereals (50 g/d) and TLR4 (P-interaction = 0.044) in relation to risk of CRC. Intake of red and processed meat also interacted with combinations of polymorphisms in TLR1 and TLR10 and polymorphisms in NFKB1, IL10, IL1B, and PTGS2 (P-interaction; TLR1/rs4833095 × PTGS2/rs20417 = 0.021, TLR10/rs11096955 × IL10/rs3024505 = 0.047, TLR10/rs11096955 × PTGS2/rs20417 = 0.017, TLR10/rs4129009 × NFKB1/rs28362491 = 0.027, TLR10/rs4129009 × IL1B/rs4848306 = 0.020, TLR10/rs4129009 × IL1B/rs1143623 = 0.021, TLR10/rs4129009 × PTGS2/rs20417 = 0.027), whereas intake of dietary fiber (10 g/d) interacted with combinations of polymorphisms in TLR4, IL10, and PTGS2 (P-interaction; TLR4/rs1554973 × IL10/rs3024505 = 0.0012, TLR4/rs1554973 × PTGS2/rs20417 = 0.0041, TLR4/rs1554973 × PTGS2/rs5275 = 0.0064).

Conclusions

Our study suggests that meat intake may activate TLRs at the epithelial surface, leading to CRC via inflammation by nuclear transcription factor-κB-initiated transcription of inflammatory genes, whereas intake of fiber may protect against CRC via TLR4-mediated secretion of interleukin-10 and cyclooxygenase-2. Our results should be replicated in other prospective cohorts with well-characterized participants. The trial was registered at www.clinicaltrials.gov as NCT03250637.

An updated meta-analysis of 37 case-control studies on the association between NFKB1 -94ins/del ATTG promoter polymorphism and cancer susceptibility

As a cell survival signal, nuclear factor-kappa B (NFKB) is associated with the pathogenesis of numerous malignancies. According to several studies, NFKB1 −94ins/del ATTG promoter polymorphism is associated with the risk of different malignancies, but the results were not consistent. Therefore, we performed an updated meta-analysis based on 37 case-control studies from 33 articles (16,271 cases and 22,781 controls) to clarify the relationship. The odds ratio (OR) and 95% confidence interval (CI) were used to determine the strength of the association. We found that the NFKB1 −94ins/del ATTG promoter polymorphism was significantly associated with increased susceptibility to cancer in the recessive (II vs. ID+DD, OR = 1.140, 95% CI = 1.029–1.263, p =0.012), homozygote (II vs. DD, OR = 1.259, 95% CI = 1.068–1.485, p =0.006), and allele (I vs. D, OR = 1.109, 95% CI = 1.025–1.199, p =0.010) genetic models. The subgroup analysis for ethnicity found that the NFKB1 −94ins/del ATTG promoter polymorphism was significantly associated with an increased susceptibility to cancer in Asians and with a decreased susceptibility in Caucasians. The stratified analyses revealed significant associations between the polymorphism and increased susceptibility to ovarian cancer, oral squamous cell carcinoma, and nasopharyngeal carcinoma.

Analysis of 12 variants in the development of gastric and colorectal cancers

AIM

To evaluate the relation between 12 polymorphisms and the development of gastric cancer (GC) and colorectal cancer (CRC).

METHODS

In this study, we included 125 individuals with GC diagnosis, 66 individuals with CRC diagnosis and 475 cancer-free individuals. All participants resided in the North region of Brazil and authorized the use of their samples. The 12 polymorphisms (in CASP8, CYP2E1, CYP19A1, IL1A, IL4, MDM2, NFKB1, PAR1, TP53, TYMS, UGT1A1 and XRCC1 genes) were genotyped in a single PCR for each individual, followed by fragment analysis. To avoid misinterpretation due to population substructure, we applied a previously developed set of 61 ancestry-informative markers that can also be genotyped by multiplex PCR. The statistical analyses were performed in Structure v.2.3.4, R environment and SPSS v.20.

RESULTS

After statistical analyses with the control of confounding factors, such as genetic ancestry, three markers (rs79071878 in IL4, rs3730485 in MDM2 and rs28362491 in NFKB1) were positively associated with the development of GC. One of these markers (rs28362491) and the marker in the UGT1A1 gene (rs8175347) were positively associated with the development of CRC. Therefore, we investigated whether the joint presence of the deleterious alleles of each marker could affect the development of cancer and we obtained positive results in all analyses. Carriers of the combination of alleles RP1 + DEL (rs79071878 and rs28361491, respectively) are at 10-times greater risk of developing GC than carriers of other combinations. Similarly, carriers of the combination of DEL + RARE (rs283628 and rs8175347) are at about 12-times greater risk of developing CRC than carriers of other combinations.

CONCLUSION

These findings are important for the comprehension of gastric and CRC development, particularly in highly admixed populations, such as the Brazilian population.

Infrequently expressed miRNAs in colorectal cancer tissue and tumor molecular phenotype

We have previously shown that commonly expressed miRNAs influenced tumor molecular phenotype in colorectal cancer. We hypothesize that infrequently expressed miRNAs, when showing higher levels of expression, help to define tumor molecular phenotype. In this study, we examine 304 miRNAs expressed in at least 30 individuals, but in <50% of the population and with a mean level of expression above 1.0 relative florescent unit. We examine associations in 1893 individuals who have the tumor molecular phenotype data as well as miRNA expression levels for both carcinoma and normal colorectal tissue. We compare miRNAs uniquely associated with tumor molecular phenotype to the RNAseq data to identify genes associated with these miRNAs. This information is used to further identify unique pathways associated with tumor molecular phenotypes of TP53-mutated, KRAS-mutated, CpG island methylator phenotype and microsatellite instability tumors. Thirty-seven miRNAs were uniquely associated with TP53-mutated tumors; 30 of these miRNAs had higher level of expression in TP53-mutated tumors, while seven had lower levels of expression. Of the 34 miRNAs associated with CpG island methylator phenotype-high tumors, 16 were more likely to have a CpG island methylator phenotype-high tumor and 19 were less likely to be CpG island methylator phenotype-high. For microsatellite instability, 13 of the 22 infrequently expressed miRNAs were significantly less likely to be expressed in microsatellite unstable tumors. KRAS-mutated tumors were not associated with any miRNAs after adjustment for multiple comparisons. Of the dysregulated miRNAs, 17 were more likely to be TP53-mutated tumors while simultaneously being less likely to be CpG island methylator phenotype-high and/or microsatellite instability tumors. Genes regulated by these miRNAs were involved in numerous functions and pathways that influence cancer risk and progression. In summary, some infrequently expressed miRNAs, when expressed at higher levels, appear to have significant biological meaning in terms of tumor molecular phenotype and gene expression profiles.

Exploratory plasma proteomic analysis in a randomized crossover trial of aspirin among healthy men and women

Long-term use of aspirin is associated with lower risk of colorectal cancer and other cancers; however, the mechanism of chemopreventive effect of aspirin is not fully understood. Animal studies suggest that COX-2, NFκB signaling and Wnt/β-catenin pathways may play a role, but no clinical trials have systematically evaluated the biological response to aspirin in healthy humans. Using a high-density antibody array, we assessed the difference in plasma protein levels after 60 days of regular dose aspirin (325 mg/day) compared to placebo in a randomized double-blinded crossover trial of 44 healthy non-smoking men and women, aged 21-45 years. The plasma proteome was analyzed on an antibody microarray with ~3,300 full-length antibodies, printed in triplicate. Moderated paired t-tests were performed on individual antibodies, and gene-set analyses were performed based on KEGG and GO pathways. Among the 3,000 antibodies analyzed, statistically significant differences in plasma protein levels were observed for nine antibodies after adjusting for false discoveries (FDR adjusted p-value<0.1). The most significant protein was succinate dehydrogenase subunit C (SDHC), a key enzyme complex of the mitochondrial tricarboxylic acid (TCA) cycle. The other statistically significant proteins (NR2F1, MSI1, MYH1, FOXO1, KHDRBS3, NFKBIE, LYZ and IKZF1) are involved in multiple pathways, including DNA base-pair repair, inflammation and oncogenic pathways. None of the 258 KEGG and 1,139 GO pathways was found to be statistically significant after FDR adjustment. This study suggests several chemopreventive mechanisms of aspirin in humans, which have previously been reported to play a role in anti- or pro-carcinogenesis in cell systems; however, larger, confirmatory studies are needed.

Aberrant methylation patterns in colorectal cancer: a meta-analysis

Colorectal cancer is among the leading causes of cancer death worldwide. Despite numerous molecular characterizations of the phenomenon, the exact dynamics of its onset and progression remain elusive. Colorectal cancer onset has been characterized by changes in DNA methylation profiles, that, owing to the stability of their patterns, are promising candidates to shed light on the molecular events laying at the base of this phenomenon.To exploit this stability and reinforce it, we conducted a meta-analysis on publicly available DNA methylation datasets generated on: normal colorectal, adenoma (ADE) and adenocarcinoma (CRC) samples using the Illumina 450k array, in the systems medicine frame, searching for tumor gene episignatures, to produce a carefully selected list of potential drivers, markers and targets of the disease. The analysis proceeds from a differential meta-analysis of the methylation profiles using an analytical pipeline recently developed by our group [1], through network reconstruction, topological and functional analyses, to finally highlight relevant epigenomic features. Our results show that genes already highlighted for their genetic or transcriptional alteration in colorectal cancer are also differentially methylated, reinforcing -regardless of the level of cellular control- their role in the complex of alterations involved in tumorigenesis.These findings were finally validated in an independent cohort from The Cancer Genome Atlas (TCGA).

NFKB1 -94insertion/deletion ATTG polymorphism and cancer risk: Evidence from 50 case-control studies

Nuclear factor-kappa B1 (NF-κB1) is a pleiotropic transcription factor and key contributor to tumorigenesis in many types of cancer. Numerous studies have addressed the association of a functional insertion (I)/deletion (D) polymorphism (-94ins/delATTG, rs28362491) in the promoter region of NFKB1 gene with the risk of various types of cancer; however, their conclusions have been inconsistent. We therefore conducted a meta-analysis to reevaluate this association. PubMed, EMBASE, China National Knowledge infrastructure (CNKI), and WANFANG databases were searched through July 2016 to retrieve relevant studies. After careful assessment, 50 case-control studies, comprising 18,299 cases and 23,484 controls were selected. Crude odds ratios (ORs) and 95% confidence intervals (CIs) were used to determine the strength of the association. The NFKB1 -94ins/delATTG polymorphism was associated with a decreased risk of overall cancer in the homozygote model (DD vs. II): OR = 0.75, 95% CI = 0.64-0.87); heterozygote model (ID vs. II): OR = 0.91, 95% CI = 0.83-0.99; recessive model (DD vs. ID/II): OR = 0.81, 95% CI = 0.71-0.91; dominant model (ID/DD vs. II): OR = 0.86, 95% CI = 0.78-0.95; and allele contrast model (D vs. I): OR = 0.88, 95% CI = 0.81-0.95). Subgroup and stratified analyses revealed decreased risks for lung cancer, nasopharyngeal carcinoma, prostate cancer, ovarian cancer, and oral squamous cell carcinoma, and this association held true also for Asians (especially Chinese subjects) in hospital-based studies, and in studies with quality scores less than nine. Well-designed, large-scale case-control studies are needed to confirm these results.

Genetic association between NFKB1 -94 ins/del ATTG Promoter Polymorphism and cancer risk: a meta-analysis of 42 case-control studies

Accumulating evidences have indicated that the functional -94 ins/del ATTG polymorphism in the promoter region of human nuclear factor-kappa B1 (NFKB1) gene may be associated with cancer risk. However, some studies yielded conflicting results. To clarify precise association, we performed a comprehensive meta-analysis of 42 case-control studies involving 43,000 subjects (18,222 cases and 24,778 controls). The overall results suggested that the -94 ins/del ATTG polymorphism had a decreased risk for cancer, reaching significant levels in five genetic models (dominant model: OR = 0.86, 95% CI = 0.79–0.95, P = 0.002; recessive model: OR = 0.84, 95% CI = 0.74–0.94, P = 0.003; homozygous model: OR = 0.77, 95% CI = 0.66–0.90, P = 0.001; heterozygous model: OR = 0.90, 95% CI = 0.83–0.98, P = 0.011; allelic model: OR = 0.89, 95% CI = 0.83–0.96, P = 0.002). Furthermore, the -94 ins/del ATTG polymorphism could confer a decreased or increased risk for cancer development among Asians and Caucasians, respectively. Additionally, the stratification analysis revealed a significant association between the variant and decreased risk of oral, ovarian, and nasopharyngeal cancer in Asians. After we adjusted p values using the Benjamini-Hochberg false discovery rate method to account for multiple comparisons, these associations remained.

Pregnane X Receptor and Cancer: Context-Specificity is Key

Pregnane X receptor (PXR) is an adopted orphan nuclear receptor that is activated by a wide-range of endobiotics and xenobiotics, including chemotherapy drugs. PXR plays a major role in the metabolism and clearance of xenobiotics and endobiotics in liver and intestine via induction of drug-metabolizing enzymes and drug-transporting proteins. However, PXR is expressed in several cancer tissues and the accumulating evidence strongly points to the differential role of PXR in cancer growth and progression as well as in chemotherapy outcome. In cancer cells, besides regulating the gene expression of enzymes and proteins involved in drug metabolism and transport, PXR also regulates other genes involved in proliferation, metastasis, apoptosis, anti-apoptosis, inflammation, and oxidative stress. In this review, we focus on the differential role of PXR in a variety of cancers, including prostate, breast, ovarian, endometrial, and colon. We also discuss the future directions to further understand the differential role of PXR in cancer, and conclude with the need to identify novel selective PXR modulators to target PXR in PXR-expressing cancers.

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.

Association and interaction of NFKB1 rs28362491 insertion/deletion ATTG polymorphism and PPP1R13L and CD3EAP related to lung cancer risk in a Chinese population

The nuclear factor of kappa light polypeptide gene enhancer in B cells 1 (NFKB1) gene encodes p105 and p50 kD which are both subunits of the transcription factor NF-kB, involved in a wide variety of diseases and pathological states associated with inflammation, immunity, and tumorigenesis. The NFKB1 rs28362491 polymorphism in the promoter region (-94 insertion/deletion ATTG) has been associated with risk of various cancers. Our study aims were to evaluate the associations of NFKB1 rs28362491 polymorphism and interactions of this single-nucleotide polymorphism (SNP) and PPP1R13L and CD3EAP and smoking duration in relation to lung cancer risk in a Chinese population. The study population consisted of 544 Chinese lung cancer cases and 550 cancer-free matched (age, sex, and ethnicity) controls. No associations were found between NFKB1 rs28362491 and lung cancer risk. CD3EAP rs967591 was associated with increased lung cancer risk in the dominant model [OR (95 % CI) = 1.38 (1.05-1.80), P = 0.018]. The common haplotype containing PPP1R13L rs1970764(G), CD3EAP rs967591(A), and CD3EAP rs735482(C) was associated with lung cancer [adjusted OR (95 % CI) = 1.29 (1.03-1.62), P = 0.028]. Multifactor dimensionality reduction (MDR) analysis revealed two-way and three-way interactions between CD3EAP rs735482 and smoking and between NFKB1 rs28362491, PPP1R13L rs1970764, and smoking. In conclusion, we were able to reproduce previously found associations between PPP1R13L and CD3EAP polymorphisms and lung cancer risk in an increased study group, and we found interactions between NFKB1 rs28362491-PPP1R13L rs1970764 and smoking duration and between CD3EAP rs735482 and smoking duration. These results suggest that these genes and smoking are part of the same biological pathway leading to smoking-induced lung cancer.

Novel understanding of ABC transporters ABCB1/MDR/P-glycoprotein, ABCC2/MRP2, and ABCG2/BCRP in colorectal pathophysiology

AIM: To evaluate ATP-binding cassette (ABC) transporters in colonic pathophysiology as they had recently been related to colorectal cancer (CRC) development.

METHODS: Literature search was conducted on PubMed using combinations of the following terms: ABC transporters, ATP binding cassette transporter proteins, inflammatory bowel disease, ulcerative, colitis, Crohns disease, colorectal cancer, colitis, intestinal inflammation, intestinal carcinogenesis, ABCB1/P-glycoprotein (P-gp/CD243/MDR1), ABCC2/multidrug resistance protein 2 (MRP2) and ABCG2/breast cancer resistance protein (BCRP), Abcb1/Mdr1a, abcc2/Mrp2, abcg2/Bcrp, knock-out mice, tight junction, membrane lipid function.

RESULTS: Recently, human studies reported that changes in the levels of ABC transporters were early events in the adenoma-carcinoma sequence leading to CRC. A link between ABCB1, high fat diet and gut microbes in relation to colitis was suggested by the animal studies. The finding that colitis was preceded by altered gut bacterial composition suggests that deletion of Abcb1 leads to fundamental changes of host-microbiota interaction. Also, high fat diet increases the frequency and severity of colitis in specific pathogen-free Abcb1 KO mice. The Abcb1 KO mice might thus serve as a model in which diet/environmental factors and microbes may be controlled and investigated in relation to intestinal inflammation. Potential molecular mechanisms include defective transport of inflammatory mediators and/or phospholipid translocation from one side to the other of the cell membrane lipid bilayer by ABC transporters affecting inflammatory response and/or function of tight junctions, phagocytosis and vesicle trafficking. Also, diet and microbes give rise to molecules which are potential substrates for the ABC transporters and which may additionally affect ABC transporter function through nuclear receptors and transcriptional regulation. Another critical role of ABCB1 was suggested by the finding that ABCB1 expression identifies a subpopulation of pro-inflammatory Th17 cells which were resistant to treatment with glucocorticoids. The evidence for the involvement of ABCC2 and ABCG2 in colonic pathophysiology was weak.

CONCLUSION: ABCB1, diet, and gut microbes mutually interact in colonic inflammation, a well-known risk factor for CRC. Further insight may be translated into preventive and treatment strategies.

Exome sequencing of a colorectal cancer family reveals shared mutation pattern and predisposition circuitry along tumor pathways

The molecular basis of cancer and cancer multiple phenotypes are not yet fully understood. Next Generation Sequencing promises new insight into the role of genetic interactions in shaping the complexity of cancer. Aiming to outline the differences in mutation patterns between familial colorectal cancer cases and controls we analyzed whole exomes of cancer tissues and control samples from an extended colorectal cancer pedigree, providing one of the first data sets of exome sequencing of cancer in an African population against a background of large effective size typically with excess of variants. Tumors showed hMSH2 loss of function SNV consistent with Lynch syndrome. Sets of genes harboring insertions-deletions in tumor tissues revealed, however, significant GO enrichment, a feature that was not seen in control samples, suggesting that ordered insertions-deletions are central to tumorigenesis in this type of cancer. Network analysis identified multiple hub genes of centrality. ELAVL1/HuR showed remarkable centrality, interacting specially with genes harboring non-synonymous SNVs thus reinforcing the proposition of targeted mutagenesis in cancer pathways. A likely explanation to such mutation pattern is DNA/RNA editing, suggested here by nucleotide transition-to-transversion ratio that significantly departed from expected values (p-value 5e-6). NFKB1 also showed significant centrality along with ELAVL1, raising the suspicion of viral etiology given the known interaction between oncogenic viruses and these proteins.

The unfolded protein response, inflammation, oscillators, and disease: a systems biology approach

Non-communicable diseases (NCDs) such as cardiovascular disease, cancers, diabetes and obesity are responsible for about two thirds of mortality worldwide, and all of these ailments share a common low-intensity systemic chronic inflammation, endoplasmic reticulum stress (ER stress), and the ensuing Unfolded Protein Response (UPR). These adaptive mechanisms are also responsible for significant metabolic changes that feedback with the central clock of the suprachiasmatic nucleus (SCN) of the hypothalamus, as well as with oscillators of peripheral tissues. In this review we attempt to use a systems biology approach to explore such interactions as a whole; to answer two fundamental questions: (1) how dependent are these adaptive responses and subsequent events leading to NCD with their state of synchrony with the SCN and peripheral oscillators? And, (2) How could modifiers of the activity of SCN for instance, food intake, exercise, and drugs, be potentially used to modulate systemic inflammation and ER stress to ameliorate or even prevent NCDs?

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 between genetic polymorphisms of inflammatory response genes and the risk of ovarian cancer

BACKGROUND/PURPOSE

Inflammation plays an important role in promoting ovarian tumorigenesis and cancer progression. However, the relationship between polymorphisms in inflammatory response genes and risk of ovarian cancer remains poorly understood. In this study, we investigated the association of PPARG Pro12Ala, IL6-174G/C, E-selectin S128R, NFKB1-94 ins/del, NFKBIA-826C/T, and ICAM-1 K469E polymorphisms with ovarian cancer risk in a Chinese population.

METHODS

Genotyping of the polymorphisms was performed on 687 cases and 687 controls employing the PCR-RFLP technique, and the logistic regression model was used to measure the risk association.

RESULTS

A significantly increased risk association was observed for the heterozygous genotypes of PPARG [odds ratio (OR) = 1.52, 95% confidence interval (CI) = 1.01-2.29] and E-selectin (OR = 1.77, 95% CI = 1.07-2.93) polymorphisms, as well as the homozygous ins/ins genotype of NFKB1 polymorphism (OR = 1.39, 95% CI = 1.00-1.92). By contrast, ICAM-1 KE genotype was associated with a decreased ovarian cancer risk (OR = 0.77, 95% CI = 0.60-0.98). In addition, the NFKB1 del/del + NFKBIA TT combination was also found to be associated with a decreased ovarian cancer risk, with OR = 0.12 (95% CI = 0.01-0.95). The associations of the NFKB1 and ICAM-1 polymorphisms replicated the findings of previous reports, assuring the reliability of the results obtained.

CONCLUSION

NFKB1 and ICAM-1 polymorphisms could serve as useful ovarian cancer risk prediction biomarkers for the Chinese population, while the utility of PPARG and E-selectin polymorphisms as biomarkers requires further confirmation in independent ovarian cancer cohorts.

No association between HMOX1 and risk of colorectal cancer and no interaction with diet and lifestyle factors in a prospective Danish case-cohort study

Red meat is a risk factor for colorectal cancer (CRC). We wanted to evaluate whether a functional polymorphism in the HMOX1 gene encoding heme oxygenase modifies risk of CRC or interacts with diet or lifestyle factors because this would identify heme or heme iron as a risk factor of CRC. The HMOX1 A-413T (rs2071746) was assessed in relation to risk of colorectal cancer (CRC) and interactions with diet (red meat, fish, fiber, cereals, fruit and vegetables) and lifestyle (use of non-steroidal anti-inflammatory drug and smoking status) were assessed in a case-cohort study of 928 CRC cases and a comparison group of 1726 randomly selected participants from a prospective study of 57,053 persons. No association between HMOX1 A-413T and CRC risk was found (TT vs. AA + TA; IRR = 1.15, 95% CI: 0.98-1.36, p = 0.10 for the adjusted estimate). No interactions were found between diet or lifestyle and HMOX1 A-413T. HMOX1 A-413T was not associated with CRC risk and no interactions with diet or lifestyle were identified in this large, prospective cohort with high meat intake. The results reproduced the previous findings from the same cohort and did not support a link between heme or heme iron and colorectal cancer. These results should be sought and replicated in other well-characterized cohorts with high meat intake.

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.

Role of genetic polymorphisms in NFKB-mediated inflammatory pathways in response to primary chemoradiation therapy for rectal cancer

PURPOSE

To investigate whether polymorphisms of genes related to inflammation are associated with pathologic response (primary endpoint) in patients with rectal cancer treated with primary chemoradiation therapy (PCRT).

METHODS AND MATERIALS

Genomic DNA of 159 patients with locally advanced rectal cancer treated with PCRT was genotyped for polymorphisms rs28362491 (NFKB1), rs1213266/rs5789 (PTGS1), rs5275 (PTGS2), and rs16944/rs1143627 (IL1B) using TaqMan single nucleotide polymorphism genotyping assays. The association between each genotype and pathologic response (poor response vs complete or partial response) was analyzed using logistic regression models.

RESULTS

The NFKB1 DEL/DEL genotype was associated with pathologic response (odds ratio [OR], 6.39; 95% confidence interval [CI], 0.78-52.65; P=.03) after PCRT. No statistically significant associations between other polymorphisms and response to PCRT were observed. Patients with the NFKB1 DEL/DEL genotype showed a trend for longer disease-free survival (log-rank test, P=.096) and overall survival (P=.049), which was not significant in a multivariate analysis that included pathologic response. Analysis for 6 polymorphisms showed that patients carrying the haplotype rs28362491-DEL/rs1143627-A/rs1213266-G/rs5789-C/rs5275-A/rs16944-G (13.7% of cases) had a higher response rate to PCRT (OR, 8.86; 95% CI, 1.21-64.98; P=.034) than the reference group (rs28362491-INS/rs1143627-A/rs1213266-G/rs5789-C/rs5275-A/rs16944-G). Clinically significant (grade ≥2) acute organ toxicity was also more frequent in patients with that same haplotype (OR, 4.12; 95% CI, 1.11-15.36; P=.037).

CONCLUSIONS

Our results suggest that genetic variation in NFKB-related inflammatory pathways might influence sensitivity to primary chemoradiation for rectal cancer. If confirmed, an inflammation-related radiogenetic profile might be used to select patients with rectal cancer for preoperative combined-modality treatment.

Intestinal PTGS2 mRNA levels, PTGS2 gene polymorphisms, and colorectal carcinogenesis

Background & Aims

Inflammation is a major risk factor for development of colorectal cancer (CRC). Prostaglandin synthase cyclooxygenase-2 (COX-2) encoded by the PTGS2 gene is the rate limiting enzyme in prostaglandin synthesis and therefore plays a distinct role as regulator of inflammation.

Methods

PTGS2 mRNA levels were determined in intestinal tissues from 85 intestinal adenoma cases, 115 CRC cases, and 17 healthy controls. The functional PTGS2 polymorphisms A-1195G (rs689466), G-765C (rs20417), T8473C (rs5275) were assessed in 200 CRC cases, 991 adenoma cases and 399 controls from the Norwegian KAM cohort.

Results

PTGS2 mRNA levels were higher in mild/moderate adenoma tissue compared to morphologically normal tissue from the same individual (P<0.0001) and (P<0.035) and compared to mucosa from healthy individuals (P<0.0039) and (P<0.0027), respectively. In CRC patients, PTGS2 mRNA levels were 8–9 times higher both in morphologically normal tissue and in cancer tissue, compared to healthy individuals (P<0.0001). PTGS2 A-1195G variant allele carriers were at reduced risk of CRC (odds ratio (OR) = 0.52, 95% confidence interval (95% CI): 0.28–0.99, P = 0.047). Homozygous carriers of the haplotype encompassing the A-1195G and G-765C wild type alleles and the T8473C variant allele (PTGS2 AGC) were at increased risk of CRC as compared to homozygous carriers of the PTGS2 AGT (A-1195G, G-765C, T8473C) haplotype (OR = 5.37, 95% CI: 1.40–20.5, P = 0.014). No association between the investigated polymorphisms and PTGS2 mRNA levels could be detected.

Conclusion

High intestinal PTGS2 mRNA level is an early event in colorectal cancer development as it occurs already in mild/moderate dysplasia. PTGS2 polymorphisms that have been associated with altered PTGS2 mRNA levels/COX-2 activity in some studies, although not the present study, were associated with colorectal cancer risk. Thus, both PTGS2 polymorphisms and PTGS2 mRNA levels may provide information regarding CRC risk.

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.

A review of the application of inflammatory biomarkers in epidemiologic cancer research

Inflammation is a facilitating process for multiple cancer types. It is believed to affect cancer development and progression through several etiologic pathways, including increased levels of DNA adduct formation, increased angiogenesis, and altered antiapoptotic signaling. This review highlights the application of inflammatory biomarkers in epidemiologic studies and discusses the various cellular mediators of inflammation characterizing the innate immune system response to infection and chronic insult from environmental factors. Included is a review of six classes of inflammation-related biomarkers: cytokines/chemokines, immune-related effectors, acute-phase proteins, reactive oxygen and nitrogen species, prostaglandins and cyclooxygenase-related factors, and mediators such as transcription factors and growth factors. For each of these biomarkers, we provide a brief overview of the etiologic role in the inflammation response and how they have been related to cancer etiology and progression within the literature. We provide a discussion of the common techniques available for quantification of each marker, including strengths, weaknesses, and potential pitfalls. Subsequently, we highlight a few under-studied measures to characterize the inflammatory response and their potential utility in epidemiologic studies of cancer. Finally, we suggest integrative methods for future studies to apply multifaceted approaches to examine the relationship between inflammatory markers and their roles in cancer development.

Association between the NFKB1-94ins/del ATTG polymorphism and cancer risk: an updated meta-analysis

To assess the effect of the NFKB1 -94ins/del polymorphism on cancer, we conducted a meta-analysis based on 25 studies including 8,750 cases and 9,170 controls. Overall, the -94ins/del polymorphism was associated with cancer risk in the pooled analysis and in Asian population, whereas no association was observed in Caucasian population. Stratified analysis by subtypes of cancer showed that the -94ins/del polymorphism was associated with oral squamous cell carcinoma and ovarian cancer risk, but had no association with colorectal cancer, bladder cancer, and renal cell cancer. Our meta-analysis suggests the NFKB1 -94ins/del polymorphism affects cancer susceptibility, and the association is ethnic-specific.

Association between NFKB1 -94ins/del ATTG Promoter Polymorphism and Cancer Susceptibility: An Updated Meta-Analysis

Nuclear factor-κB is associated with the pathogenesis of numerous malignancies, and the functional polymorphism −94ins/del ATTG (rs28362491) in the human NFKB1 gene is associated with cancer risk. Previous studies on the association between the −94ins/del ATTG polymorphism and cancer risk reported conflicting results. To clarify this relationship, we performed a meta-analysis of 21 case-control studies involving 6127 cases and 9238 controls. We used pooled odds ratios (ORs) with their 95% confidence intervals (95% CIs) to assess the association. We found that the NFKB1 promoter −94ins/del ATTG polymorphism was significantly associated with cancer risk in four genetic models (ins/ins versus del/del, OR = 1.47, 95% CI = 1.11–1.93; dominant model, OR = 1.26, 95% CI = 1.03–1.53; recessive model, OR = 1.26, 95% CI = 1.05–1.51; ins allele versus del allele, OR = 1.19, 95% CI = 1.05–1.35). Stratified analyses revealed a significant association between the polymorphism and ovarian, oral, and prostate cancers. Similar results were determined in an Asian population and not in a Caucasian population. Thus, our results suggested that the polymorphism can contribute to cancer risk. Moreover, the polymorphism can exert race- and cancer-specific effects on cancer risk. Further large-scale and functional studies are necessary to elucidate this possible effect.

Genetic polymorphism of NFKB1 and NFKBIA genes and liver cancer risk: a nested case-control study in Shanghai, China

OBJECTIVES

Genetic variations of nuclear factor-κB (NF-κB) signalling pathway were found to be associated with inflammatory diseases and several malignancies. However, little is known about NF-κB pathway gene polymorphisms and susceptibility of liver cancer. The aim of this study was to investigate whether genetic variants of NFKB1 and NFKBIA were associated with risk of liver cancer in a Chinese population.

DESIGN

The study was designed as a nested case-control study within two prospective cohorts (the Shanghai Women's Health Study, SWHS, 1996-2000 and the Shanghai Men's Health Study, SMHS, 2002-2006).

SETTINGS

This population-based study was conducted in urban Shanghai, China.

PARTICIPANTS

A total of 217 incident liver cancer cases diagnosed through 31 December 2009 and 427 healthy controls matched by sex, age at baseline (±2 years) and date (±30 days) of sample collection were included in the study.

PRIMARY AND SECONDARY OUTCOME MEASURES

Genetic polymorphisms of NFKB1 and NFKBIA were determined blindly by TaqMan single-nucleotide polymorphism (SNP) genotyping assay. OR and its 95% CIs were estimated by an unconditional logistic regression model to measure the association between selected SNPs and the risk of liver cancer.

RESULTS

After adjusted for potential confounding factors, rs28362491 ins/del or del/del genotypes were associated with higher risk of liver cancer with an adjusted OR 1.54 (95% CI 1.04 to 2.28). rs230496 AG and GG genotypes were also noted with higher risk of liver cancer with an adjusted OR 1.53 (95% CI 1.03 to 2.26). Haplotype analysis indicated that carriers of the NFKB1 GA and AA (rs230525-rs230530) haplotypes had higher risk of liver cancer under an additive model. No association was observed between NFKBIA variants and risk of live cancer.

CONCLUSIONS

Our results suggest that genetic variants of NFKB1 influence liver cancer susceptibility in Chinese population, although replication in other studies is needed.

NFKB1 -94 insertion/deletion polymorphism and cancer risk: a meta-analysis

Previous studies on the associations of the NFKB1 -94 insertion/deletion polymorphism with cancer risk have produced conflicting results. The purpose of this meta-analysis is to define the effect of the NFKB1 -94 insertion/deletion polymorphism on cancer risk. A search of the literature by PubMed was performed to identify studies based on the predetermined inclusion criteria. Twenty-three studies consisting of 6,494 cases and 9,884 controls were identified and analyzed. Overall, significant association was observed between the polymorphism and cancer risk under all genetic models. Subgroup analysis according to ethnicity and cancer type also detected significant association. The NFKB1 -94 insertion/deletion polymorphism was associated with cancer risk in Asian population (dominant model: OR=1.52, 95 % CI=1.17-1.98; recessive model: OR=1.50, 95 % CI=1.26-1.79; II vs. DD: OR=1.90, 95 % CI=1.37-2.65; ID vs. DD: OR=1.32, 95 % CI=1.05-1.66; I vs. D: OR=1.37, 95 % CI=1.17-1.60), but not in Caucasian population. In addition, significant associations in OC, HCC, and OSCC were observed, but significant associations were not found in BC and LC. The current meta-analysis suggested that NFKB1 -94 insertion/deletion polymorphism may influence cancer risk in Asian population.

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.

Functional promoter polymorphisms of NFKB1 influence susceptibility to the diffuse type of gastric cancer

In the present study, we report an association between gastric cancer and polymorphisms in NFKB1 (rs28362941 and rs78696119). We employed the PCR-SSCP method to detect gene polymorphisms in 479 gastric cancer cases and 880 controls. The rs28362941 del/del homozygote was significantly associated with gastric cancer development; in particular it was closely associated with diffuse type gastric cancer. The rs78696119 GG homozygote was also associated with the diffuse type of gastric cancer. In young subjects, both polymorphisms were significantly associated with the development of gastric cancer. In addition, both polymorphisms were related to tumor progression such as tumor invasion and lymph node metastasis. The inflammatory cell infiltration into non-cancerous gastric mucosa was greater in the subjects with the rs28362491 del/del or rs78696119 GG genotype when compared to those with the other genotypes. In conclusion, functional polymorphisms of NFKB1 are associated with an increased risk of gastric cancer; in particular they are closely associated with the development of diffuse type of gastric cancer via severe gastric inflammation. These polymorphisms also appear to be associated with gastric cancer progression.

Transcriptome analysis and SNP identification in SCC of horn in (Bos indicus) Indian cattle

Single Nucleotide Polymorphisms (SNPs) have become the marker of choice for genome wide association studies. In order to provide the best genome coverage for the analysis of disease, production and performance traits, a large number of relatively evenly distributed SNPs are needed. The main objective of present work was to identify large numbers of gene-associated SNPs using high-throughput sequencing in squamous cell carcinoma of horn. RNA-seq analysis was conducted on 2 tissues viz. Horn Cancer (HC) and Horn Normal (HN) in Kankrej breed of cattle. A total of 909,362 reads with average read length of 405 bp for HC and 583,491 reads with average read length of 411 bp for HN were obtained. We found 9532 and 7065 SNPs as well as 1771 and 1172 Indels in HC and HN, respectively, from which, 7889 SNPs and 1736 Indels were uniquely present in HC, 5886 SNPs and 1146 Indels were uniquely present in HN and reported first time in Bos indicus, whereas the rest are already reported in Bos taurus dbSNP database. The gene-associated SNPs and Indels were high in upregulated genes of HC as compared to HN. Analysis of differentially expressed genes was identified, these genes are involved in regulation of cell proliferation, apoptosis, gene transcription, cell survival and metabolism through various metabolic pathways. The result of transcriptome expression profiling was validated using Real Time quantitative PCR in nine randomly selected genes. We identified numbers aberrant signaling pathways responsible for carcinogenesis in HC which are also commonly altered in squamous cell carcinoma (SCC) of lung in human being. We conclude that a large number of altered genes and dysfunction of multiple pathways are involved in the development of Horn Cancer. The present findings contribute to theoretical information for further screening of genes and identification of markers for early diagnosis of HC as well as SNPs identified in this report provide a much needed resource for genetic studies in B. indicus and shall contribute to the development of a high density SNP array. Validation and testing of these SNPs using SNP arrays will form the material basis for gene associated SNPs in HC.

Low ABCB1 gene expression is an early event in colorectal carcinogenesis

The ABCB1/MDR1 gene product ABCB1/P-glycoprotein is implicated in the development of colorectal cancer (CRC). NFKB1 encodes transcription factors regulating expression of a number of genes including ABCB1. We have previously found association between the ABCB1 C-rs3789243-T polymorphism and CRC risk and interactions between the ABCB1 C-rs3789243-T and C3435T polymorphisms and meat intake in relation to CRC risk (Andersen, BMC Cancer, 2009, 9, 407). ABCB1 and NFKB1 mRNA levels were assessed in intestinal tissue from 122 CRC cases, 101 adenoma cases (12 with severe dysplasia, 89 with mild-moderate dysplasia) and from 18 healthy individuals, together with gene polymorphisms in ABCB1 and NFKB1. ABCB1 mRNA levels were highest in the healthy individuals and significantly lower in mild/moderate and severe dysplasia tissue (P<0.05 for both), morphologically normal tissues close to the tumour (P<0.05), morphologically normal tissue at a distance from the tumour (P<0.05) and CRC tissue (P<0.001). Furthermore, ABCB1 mRNA levels were lower in adenomas and carcinomas compared to morphologically normal tissue from the same individuals (P<0.01). The ABCB1 C-rs3789243-T and NFKB1 -94ins/del homozygous variant genotypes were associated with low ABCB1 mRNA levels in morphologically normal sigmoid tissue from adenoma cases (P<0.05 for both). NFKB1 mRNA levels were lower in both tumour and normal tissue from cancer patients (P<0.001) as compared to healthy individuals but we were unable to show association between NFKB1 -94ins/del genotype and NFKB1 mRNA levels. This study suggests that low ABCB1 mRNA levels are an early event in CRC development and that the two polymorphisms affect ABCB1 mRNA levels whereas low NFKB1 mRNA levels occur later in carcinogenesis. Low ABCB1 protein levels may promote colorectal carcinogenesis through increasing intracellular exposure to carcinogenic ABCB1 substrates.

Association of liver X receptors (LXRs) genetic variants to gallbladder cancer susceptibility

Liver X receptors (LXRs) α and β are ligand-activated transcription factors belonging to the family of nuclear receptors. LXRs play role in control of lipid homeostasis, glucose metabolism, inflammation, and proliferation. LXRs are expressed in gallbladder cholangiocytes and recent studies have shown that LXR-β (-/-) Mice exhibit an estrogen-dependent gallbladder carcinogenesis. However, there are no studies reported in humans. Therefore, using case-control design in the present study, we have evaluated the associations of LXR-α (rs7120118) and LXR-β (rs35463555 and rs2695121) genetic variants with gallbladder cancer (GBC) susceptibility in 400 cases and 200 controls. Genotypes were determined by TaqMan probes. Statistical analysis was done by SPSS and SNPstats. In silico analysis was performed using Bioinformatics tools (F-SNP, FAST-SNP). LXR-β genotypes (rs35463555) [GA + AA] and (rs2695121) [TC + CC] were associated with risk of GBC [OR = 1.46, p = 0.03; OR = 1.52, p = 0.01, respectively] as compared to healthy controls whereas LXR-α (rs7120118) was not associated with GBC risk. LXR-β haplotype [Ars35463555-Crs2695121] showed statistical significant association with GBC [OR = 5.0, p = 0.03]. On stratification based on gender, LXR-β [GA + AA] and [TC + CC] genotypes were found to be significantly associated in females GBC patients [OR = 1.5, p = 0.04; OR = 1.7, p = 0.005, respectively]. The LXR-β [TC + CC] associated with GBC patients with gallstones [OR; 1.8, p = 0.002]. The genetic risk by LXR-β was not modulated by tobacco consumption or age of onset. In silico analysis using FAST-SNP showed "Low-medium risk" by LXR-β (rs2695121) T > C variation. Our results suggest that LXR-β polymorphisms influence gallbladder cancer susceptibility through estrogen and gallstone-dependent pathways.

The functional -94 insertion/deletion ATTG polymorphism in the promoter region of NFKB1 gene increases the risk of sporadic colorectal cancer

OBJECTIVE

To investigate the allele and genotype frequencies of NFKB1 -94 ins/del ATTG (rs28720239) polymorphism and to evaluate the association between the polymorphism and colorectal cancer (CRC) risk in Malaysian population.

METHODS

Genomic DNA was extracted from the peripheral blood samples of 474 study subjects, which consisted of 237 histopathologically confirmed CRC patients and an equal number of cancer-free controls. The NFKB1 -94 ins/del ATTG (rs28720239) polymorphism was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and confirmed by DNA sequencing. The association between the polymorphic genotypes and CRC risk was evaluated by deriving odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression analysis.

RESULTS

The frequencies of wildtype (del/del), heterozygous (del/ins) and variant (ins/ins) genotypes in CRC patients were 31.7%, 53.6% and 14.8%, respectively, while those in cancer-free controls were 35.0%, 58.2% and 6.8%, respectively. The frequency of the variant genotype was significantly higher in cases compared to controls (P<0.01). Evaluation of the risk association of the polymorphic genotypes revealed that the variant genotype could contribute to a significantly increased risk of CRC (OR=2.42, 95% CI=1.24-4.73, P<0.01).

CONCLUSIONS

The variant allele of NFKB1 -94 ins/del ATTG (rs28362491) polymorphism is associated with higher risk of sporadic CRC in Malaysian population.

Redox regulation of T-cell function: from molecular mechanisms to significance in human health and disease

Reactive oxygen species (ROS) are thought to have effects on T-cell function and proliferation. Low concentrations of ROS in T cells are a prerequisite for cell survival, and increased ROS accumulation can lead to apoptosis/necrosis. The cellular redox state of a T cell can also affect T-cell receptor signaling, skewing the immune response. Various T-cell subsets have different redox statuses, and this differential ROS susceptibility could modulate the outcome of an immune response in various disease states. Recent advances in T-cell redox signaling reveal that ROS modulate signaling cascades such as the mitogen-activated protein kinase, phosphoinositide 3-kinase (PI3K)/AKT, and JAK/STAT pathways. Also, tumor microenvironments, chronic T-cell stimulation leading to replicative senescence, gender, and age affect T-cell susceptibility to ROS, thereby contributing to diverse immune outcomes. Antioxidants such as glutathione, thioredoxin, superoxide dismutase, and catalase balance cellular oxidative stress. T-cell redox states are also regulated by expression of various vitamins and dietary compounds. Changes in T-cell redox regulation may affect the pathogenesis of various human diseases. Many strategies to control oxidative stress have been employed for various diseases, including the use of active antioxidants from dietary products and pharmacologic or genetic engineering of antioxidant genes in T cells. Here, we discuss the existence of a complex web of molecules/factors that exogenously or endogenously affect oxidants, and we relate these molecules to potential therapeutics.