PTGS2 (COX-2) -765G > C Promoter Variant Reduces Risk of Colorectal Adenoma among Nonusers of Nonsteroidal Anti-inflammatory Drugs

Two genome-wide interaction loci modify the association of nonsteroidal anti-inflammatory drugs with colorectal cancer

Regular, long-term aspirin use may act synergistically with genetic variants, particularly those in mechanistically relevant pathways, to confer a protective effect on colorectal cancer (CRC) risk. We leveraged pooled data from 52 clinical trial, cohort, and case-control studies that included 30,806 CRC cases and 41,861 controls of European ancestry to conduct a genome-wide interaction scan between regular aspirin/nonsteroidal anti-inflammatory drug (NSAID) use and imputed genetic variants. After adjusting for multiple comparisons, we identified statistically significant interactions between regular aspirin/NSAID use and variants in 6q24.1 (top hit rs72833769), which has evidence of influencing expression of TBC1D7 (a subunit of the TSC1-TSC2 complex, a key regulator of MTOR activity), and variants in 5p13.1 (top hit rs350047), which is associated with expression of PTGER4 (codes a cell surface receptor directly involved in the mode of action of aspirin). Genetic variants with functional impact may modulate the chemopreventive effect of regular aspirin use, and our study identifies putative previously unidentified targets for additional mechanistic interrogation.

Interactions of Colorectal Cancer, Dietary Fats, and Polymorphisms of Arachidonate Lipoxygenase and Cyclooxygenase Genes: A Literature Review

Objective

Genetics and dietary factors play important roles in the development of colorectal cancer (CRC). However, the underlying mechanisms of the interactions between CRC, gene polymorphisms, and dietary fat are unclear. This review study investigated the effects of polymorphisms of arachidonate lipoxygenase (ALOX) and cyclooxygenase (COX) genes in the association between CRC and dietary fat.

Methods

All the related papers published from 2000 to 2022 were collected from different databases such as PubMed, Science Direct, Scopus, and Cochran using related keywords such as colorectal cancer, ALOX, COX, polymorphism, and dietary fat. Non-English and unrelated documents were excluded.

Results

Some single-nucleotide polymorphisms (SNPs) in the ALOX and COX genes, such as rs2228065, rs6413416, and rs4986832 in the ALOX gene, and rs689465 in the COX gene may play significant roles in the association between the risk of CRC and dietary fats. SNPs of ALOX and COX genes may influence the effects of dietary fatty acids on the risk of CRC.

Conclusion

Some polymorphisms of the ALOX and COX genes may have important roles in the effects of dietary fat on the risk of CRC. If future studies confirm these results, dietary recommendations for preventing colorectal cancer may be personalized based on the genotype of the ALOX and COX genes.

Investigation on the mechanisms of guiqi huoxue capsule for treating cervical spondylosis based on network pharmacology and molecular docking

BACKGROUND

Guiqi huoxue capsule (GQHXC) is a patented Chinese medicine used for treating a liver and kidney deficiency and blood stasis syndrome due to qi deficiency. It is caused by cervical spondylosis (cervical spondylotic radiculopathy (CSR), mixed cervical spondylosis mainly composed of nerve root type). Its underlying mechanisms need, however, to be further clarified.

METHODS

In this study, collecting compounds, predicting therapeutic targets, constructing networks, and analyzing biological functions and pathways were based on network pharmacology analysis. In addition, molecular docking verification was engaged to assess the binding potential of selected target-compound pairs.

RESULTS

We established 5 networks: compound-putative target network of GQHXC, protein-protein interaction (PPI) network related to CSR, compound-CSR target network, potential therapeutic targets PPI network, and herb-compound-target-pathway network. Network analysis indicated that 7 targets (tumor necrosis factor [TNF], interleukin 6 [IL6], nitric oxide synthase 3 [NOS3], Interleukin-8 [CXCL8], prostaglandin-endoperoxide synthase 2 [PTGS2], vascular endothelial growth factor A [VEGFA], and AP-1 transcription factor subunit [JUN]) might be the therapeutic targets of GQHXC in CSR. Moreover, molecular docking verification showed that TNF, IL6, NOS3, CXCL8, PTGS2, VEGFA, and JUN had a good is interaction with the corresponding compounds. Furthermore, enrichment analysis indicated that GQHXC might exert a curative role in CSR by regulating some important pathways, such as TNF signaling pathway, NF-kappa B signaling pathway, AGE-RAGE signaling pathway in diabetic complications, and so on.

CONCLUSION

Our study preliminarily explained the underlying mechanisms of GQHXC for treating CSR, and molecular docking verification was adopted as an additional verification. These findings laid a valuable foundation for experimental research and further application of GQHXC in the clinical treatment of CSR.

Anastomotic leak in colorectal cancer patients: New insights and perspectives

Anastomotic leak (AL) remains a potentially life-threatening sequela of colorectal surgery impacting on mortality, short- and long-term morbidity, quality of life, local recurrence (LR) and disease-free survival. Despite technical improvements and the identification of several surgery- and patient-related factors associated to the risk of AL, its incidence has not significantly changed over time. In this context, the clarification of the mechanisms underlying anastomotic healing remains an important unmet need, crucial for improving patients' outcomes. This review concentrates on novel key findings in the etiopathogenesis of AL, how they can contribute in determining LR, and measures which may contribute to reducing its incidence. AL results from a complex, dynamic interplay of several factors and biological processes, including host genetics, gut microbiome, inflammation and the immune system. Many of these factors seem to act in concert to drive both AL and LR, even if the exact mechanisms remain to be elucidated. The next generation sequencing technology, including the microbial metagenomics, could lead to tailored bowel preparations targeting only those pathogens that can cause AL. Significant progress is being made in each of the reviewed areas, moving toward translational and targeted therapeutic strategies to prevent the difficult complication of AL.

Cyclooxygenase-2 Gene Polymorphisms -765G>C and -1195A>G and Mycosis Fungoides Risk

BACKGROUND

Cyclooxygenase-2 (COX-2) is an inducible modulator of inflammation that acts through increasing prostaglandin levels and has been described as a major mediator linking inflammation to cancer. Previous studies supported that COX-2-765G>C and -1195A>G polymorphisms were associated with increased risk of several solid tissue cancers as well as some hematological malignancies.

OBJECTIVE

The aim of the study was to elucidate the association between functional COX-2 genotypes (-765G>C and -1195A>G) polymorphisms and the risk of developing mycosis fungoides (MF).

METHODS

This was a hospital-based, case-control study of 70 MF patients and 100 MF-free controls. We genotyped COX-2 -1195A>G, -765G>C, and -8473T>C polymorphisms by using the PCR-restriction fragment length polymorphism method.

RESULTS

The AA genotype in the COX-2 -1195A>G gene polymorphism and the GC genotype in the COX-2 -765G>C gene were significantly more frequent among MF patients compared to controls (p< 0.001 and p = 0.002, respectively).

CONCLUSION

The -results indicate a possible role of COX-2 genes in the pathogenesis of MF. These novel findings may allow for notable future advances, as it will enable the identification of the -individuals most susceptible to MF.

Prostaglandin-endoperoxide synthase 2 (cyclooxygenase-2), a complex target for colorectal cancer prevention and therapy

A plentiful literature has linked colorectal cancer (CRC) to inflammation and prostaglandin-endoperoxide synthase (PTGS)2 expression. Accordingly, several nonsteroidal antiinflammatory drugs (NSAIDs) have been tested often successfully in CRC chemoprevention despite their different ability to specifically target PTGS2 and the low or null expression of PTGS2 in early colon adenomas. Some observational studies showed an increased survival for patients with CRC assuming NSAIDs after diagnosis, but no clinical trial has yet demonstrated the efficacy of NSAIDs against established CRC, where PTGS2 is expressed at high levels. The major limits for the application of NSAIDs, or specific PTGS2 inhibitors, as adjuvant drugs in CRC are (1) a frequent confusion about the physiological role of PTGS1 and PTGS2, reflecting in CRC pathology and therapy; (2) the presence of unavoidable side effects linked to the intrinsic function of these enzymes; (3) the need of established criteria and markers for patient selection; and (4) the evaluation of the immunomodulatory potential of PTGS2 inhibitors as possible adjuvants for immunotherapy. This review has been written to rediscover the multifaceted potential of PTGS2 targeting, hoping it could act as a starting point for a new and more aware application of NSAIDs against CRC.

The triune of intestinal microbiome, genetics and inflammatory status and its impact on the healing of lower gastrointestinal anastomoses

Gastrointestinal resections are a common operation and most involve an anastomosis to rejoin the ends of the remaining bowel to restore gastrointestinal (GIT) continuity. While most joins heal uneventfully, in up to 26% of patients healing fails and an anastomotic leak (AL) develops. Despite advances in surgical technology and techniques, the rate of anastomotic leaks has not decreased over the last few decades raising the possibility that perhaps we do not yet fully understand the phenomenon of AL and are thus ill-equipped to prevent it. As in all complex conditions, it is necessary to isolate each different aspect of disease for interrogation of its specific role, but, as we hope to demonstrate in this article, it is a dangerous oversimplification to consider any single aspect as the full answer to the problem. Instead, consideration of important individual observations in parallel could illuminate the way forward towards a possibly simple solution amidst the complexity. This article details three aspects that we believe intertwine, and therefore should be considered together in wound healing within the GIT during postsurgical recovery: the microbiome, the host genetic make-up and their relationship to the perioperative inflammatory status. Each of these, alone or in combination, has been linked with various states of health and disease, and in combining these three aspects in the case of postoperative recovery from bowel resection, we may be nearer an answer to preventing anastomotic leaks than might have been thought just a few years ago.

Interaction between polymorphisms in aspirin metabolic pathways, regular aspirin use and colorectal cancer risk: A case-control study in unselected white European populations

Regular aspirin use is associated with reduced risk of colorectal cancer (CRC). Variation in aspirin's chemoprevention efficacy has been attributed to the presence of single nucleotide polymorphisms (SNPs). We conducted a meta-analysis using two large population-based case-control datasets, the UK-Leeds Colorectal Cancer Study Group and the NIH-Colon Cancer Family Registry, having a combined total of 3325 cases and 2262 controls. The aim was to assess 42 candidate SNPs in 15 genes whose association with colorectal cancer risk was putatively modified by aspirin use, in the literature. Log odds ratios (ORs) and standard errors were estimated for each dataset separately using logistic regression adjusting for age, sex and study site, and dataset-specific results were combined using random effects meta-analysis. Meta-analysis showed association between SNPs rs6983267, rs11694911 and rs2302615 with CRC risk reduction (All P<0.05). Association for SNP rs6983267 in the CCAT2 gene only was noteworthy after multiple test correction (P = 0.001). Site-specific analysis showed association between SNPs rs1799853 and rs2302615 with reduced colon cancer risk only (P = 0.01 and P = 0.004, respectively), however neither reached significance threshold following multiple test correction. Meta-analysis of SNPs rs2070959 and rs1105879 in UGT1A6 gene showed interaction between aspirin use and CRC risk (Pinteraction = 0.01 and 0.02, respectively); stratification by aspirin use showed an association for decreased CRC risk for aspirin users having a wild-type genotype (rs2070959 OR = 0.77, 95% CI = 0.68-0.86; rs1105879 OR = 0.77 95% CI = 0.69-0.86) compared to variant allele cariers. The direction of the interaction however is in contrast to that published in studies on colorectal adenomas. Both SNPs showed potential site-specific interaction with aspirin use and colon cancer risk only (Pinteraction = 0.006 and 0.008, respectively), with the direction of association similar to that observed for CRC. Additionally, they showed interaction between any non-steroidal anti-inflammatory drugs (including aspirin) use and CRC risk (Pinteraction = 0.01 for both). All gene x environment (GxE) interactions however were not significant after multiple test correction. Candidate gene investigation indicated no evidence of GxE interaction between genetic variants in genes involved in aspirin pathways, regular aspirin use and colorectal cancer risk.

Cyclooxygenase-2 Is Essential for Colorectal Anastomotic Healing

OBJECTIVE

To study the effects of COX-2 on colonic surgical wound healing.

BACKGROUND

Cyclooxygenase-2 (COX-2) is a key enzyme in gastrointestinal homeostasis. COX-2 inhibitors have been associated with colonic anastomotic leakage.

METHODS

Wildtype, COX-2 knockout and COX-2 heterozygous mice were subjected to a model of colonic anastomotic leakage, and were treated with vehicle, diclofenac, or prostaglandin E2 (PGE2), the most important COX-2 product in the intestine. We assessed anastomotic leakage, mortality, angiogenesis, and inflammation. Furthermore, we investigated the association between anastomotic leakage and a human polymorphism of the COX-2 gene resulting in low COX-2 levels.

RESULTS

Diclofenac, a nonsteroidal anti-inflammatory drug inhibiting COX-2, increased anastomotic leakage compared to vehicle-treated mice (100% vs 25%, respectively). Similarly, 92% of COX-2-deficient mice developed anastomotic leakage (P = 0.003) compared to WT. PGE2 partly rescued this severe phenotype because only 46% of PGE2-administered COX-2 knockout mice developed anastomotic leakage (P = 0.02). This may be related to decreased neovascularization, because decreased CD31 staining, indicating less blood vessels, was observed in COX-2 mice (2 vessels/mm vs 6 vessels/mm in controls (P = 0.03)). This effect could partly be reversed by administration of PGE2 to COX-2 mice. No significant differences in inflammation were found. PTGS2-765G>C polymorphism in humans, associated with reduced COX-2 expression, was associated with higher anastomotic leakage rates.

CONCLUSIONS

COX-2-induced PGE2 production is essential for intestinal wound healing after colonic surgery, possibly via its effects on angiogenesis. These data emphasize that COX-2 inhibitors should be avoided after colonic surgery, and administration of PGE2 might be favorable for a selection of patients.

SP and KLF Transcription Factors in Digestive Physiology and Diseases

Specificity proteins (SPs) and Krüppel-like factors (KLFs) belong to the family of transcription factors that contain conserved zinc finger domains involved in binding to target DNA sequences. Many of these proteins are expressed in different tissues and have distinct tissue-specific activities and functions. Studies have shown that SPs and KLFs regulate not only physiological processes such as growth, development, differentiation, proliferation, and embryogenesis, but pathogenesis of many diseases, including cancer and inflammatory disorders. Consistently, these proteins have been shown to regulate normal functions and pathobiology in the digestive system. We review recent findings on the tissue- and organ-specific functions of SPs and KLFs in the digestive system including the oral cavity, esophagus, stomach, small and large intestines, pancreas, and liver. We provide a list of agents under development to target these proteins.

Biphasic responses of human vascular smooth muscle cells to magnesium ion

Magnesium-based alloys are promising in biodegradable cardiovascular stent applications. The degradation products of magnesium stents may have significant impacts on the surrounding vascular cells. However, knowledge on the interactions between magnesium ion and vascular cells at the molecular and cellular levels is still largely missing. Vascular smooth muscle cell (SMC) plays an important role in the pathogenesis of restenosis and wound healing after stent implantation. This study evaluated the short-term effects of extracellular magnesium ion (Mg(2+)) on the cellular behaviors of SMCs. Cellular responses to Mg(2+) were biphasic and in a concentration-dependent manner. Low concentrations (10 mM) of Mg(2+) increased cell viability, cell proliferation rate, cell adhesion, cell spreading, cell migration rate, and actin expression. In contrast, higher concentrations (40-60 mM) of Mg(2+) had deleterious effects on cells. Gene expression analysis revealed that Mg(2+) altered the expressions of genes mostly related to cell adhesion, cell injury, angiogenesis, inflammation, coagulation, and cell growth. Finding from this study provides some valuable information on SMC responses toward magnesium ions at the cellular and molecular levels, and guidance for future controlled release of magnesium from the stent material.

Cyclooxygenase-2 gene polymorphisms and the risk of colorectal cancer: A population-based study

The aim of the present study was to determine the association between polymorphisms in the cyclooxygenase-2 (COX-2) gene promoter region, rs20417 G/C and rs2745557 G/A, and the susceptibility to colorectal cancer (CRC) in a Han Chinese population in Shaanxi, China. Polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) were used to detect the polymorphisms of COX-2, rs20417 G/C and rs2745557 G/A, in 300 patients with CRC and 300 healthy individuals in the present case-control study. The results revealed that for the COX-2 rs20417 G/C polymorphism, the GC+CC allele frequency was 80% in CRC patients and 71% in healthy controls [odds ratio (OR)=1.63; 95% confidence interval (CI), 1.12-2.38; P=0.01]. For the COX-2 rs2745557 G/A polymorphism, the GA+AA allele frequency was 84% in CRC patients and 73% in healthy controls (OR=1.94; 95% CI, 1.30-2.90; P<0.01). In addition, among individuals with a smoking history, drinking history or family history of CRC, those who were COX-2 rs20417 (GC+CC) or COX-2 rs2745557 (GA+AA) carriers had a significantly increased risk of developing CRC compared with that of GG genotype carriers (P<0.05). Furthermore, the allelic frequencies of COX-2 rs20417 G/C and rs2745557 G/A in patients with lymph node metastasis in stage III/IV of CRC were significantly different from those of COX-2 rs20417 G/C and rs2745557 G/A in patients without lymph node metastasis in stage I/II (P<0.05). In conclusion, the results of the present study revealed that COX-2 rs20417 C allele carriers and rs2745557 A allele carriers have a significantly increased risk of CRC compared with GG genotype carriers; in addition, the frequencies of these alleles were demonstrated to be associated with lymph node metastasis and CRC progression.

The -765G>C polymorphism in the cyclooxygenase-2 gene and digestive system cancer: a meta-analysis

BACKGROUND

Published data regarding associations between the -765G>C polymorphism in cyclooxygenase-2 (COX-2) gene and digestive system cancer risk have been inconclusive. The aim of this study was to comprehensively evaluate the genetic risk of the -765G>C polymorphism in the COX-2 gene for digestive system cancer.

MATERIALS AND METHODS

A search was performed in Pubmed, Medline (Ovid), Embase, CNKI, Weipu, Wanfang and CBM databases, covering all studies until Feb 10, 2014. Statistical analysis was performed using Revman5.2.

RESULTS

A total of 10,814 cases and 16,174 controls in 38 case-control studies were included in this meta-analysis. The results indicated that C allele carriers (GC+CC) had a 20% increased risk of digestive system cancer when compared with the homozygote GG (odds ratio (OR)=1.20, 95% confidence interval (CI), 1.00-1.44 for GC+CC vs GG). In the subgroup analysis by ethnicity, significant elevated risks were associated with C allele carriers (GC+CC) in Asians (OR = 1.46, 95% CI=1.07-2.01, and p=0.02) and Africans (OR=2.12, 95% CI=1.57-2.87, and p< 0.00001), but not among Caucasians, Americans and mixed groups. For subgroup analysis by cancer type (GC+CC vs GG), significant associations were found between the -765G>C polymorphism and higher risk for gastric cancer (OR=1.64, 95% CI=1.03-2.61, and p=0.04), but not for colorectal cancer, oral cancer, esophageal cancer, and others. Regarding study design (GC+CC vs GG), no significant associations were found in then population-based case-control (PCC), hospital-based case-control (HCC) and family-based case-control (FCC) studies.

CONCLUSIONS

This meta-analysis suggested that the -765G>C polymorphism of the COX-2 gene is a potential risk factor for digestive system cancer in Asians and Africans and gastric cancer overall.

The prostaglandin synthase 2/cyclooxygenase 2 (PTGS2/ COX2) rs5277 polymorphism does not influence risk of colorectal cancer in an Iranian population

BACKGROUND

The prostaglandin-endoperoxide synthase 2 [PTGS2, commonly known as cyclooxygenase-2 (COX-2)] is an enzyme induced by proinflammatory stimuli that is often overexpressed in malignant tissue and involved in the synthesis of prostaglandins and thromboxanes, regulators of processes such as inflammation, cell proliferation, and angiogenesis, all relevant for cancer development. We investigated whether a functional genetic polymorphism, rs5277, in COX-2 may have a risk-modifying effect on sporadic colorectal cancer in an Iranian population.

MATERIALS AND METHODS

We conducted a case-control study on 167 patients with colorectal cancer and 197 cancer-free controls in Taleghani Hospital in Tehran, Iran, between 2007 and 2011. Peripheral blood samples of both groups were processed for DNA extraction and genotyping of the COX-2 gene polymorphism (rs5277) using PCR-RFLP. RFLP results were confirmed by direct sequencing. Logistic regression analysis was performed to calculate the adjusted odds ratio (OR) and 95% confidence interval (95% CI).

RESULTS

There was no significant difference in the distribution of COX-2 gene rs5277 polymorphism genotype and the allelic form, among CRC patients compared with the healthy control group (p: 0.867).

CONCLUSIONS

Our results suggest that rs5277 polymorphism in COX2 could not be a good prognostic indicator for patients with CRC.

Sp1 and the 'hallmarks of cancer'

For many years, transcription factor Sp1 was viewed as a basal transcription factor and relegated to a role in the regulation of so-called housekeeping genes. Identification of Sp1's role in recruiting the general transcription machinery in the absence of a TATA box increased its importance in gene regulation, particularly in light of recent estimates that the majority of mammalian genes lack a TATA box. In this review, we briefly consider the history of Sp1, the founding member of the Sp family of transcription factors. We review the evidence suggesting that Sp1 is highly regulated by post-translational modifications that positively and negatively affect the activity of Sp1 on a wide array of genes. Sp1 is over-expressed in many cancers and is associated with poor prognosis. Targeting Sp1 in cancer treatment has been suggested; however, our review of the literature on the role of Sp1 in the regulation of genes that contribute to the 'hallmarks of cancer' illustrates the extreme complexity of Sp1 functions. Sp1 both activates and suppresses the expression of a number of essential oncogenes and tumor suppressors, as well as genes involved in essential cellular functions, including proliferation, differentiation, the DNA damage response, apoptosis, senescence and angiogenesis. Sp1 is also implicated in inflammation and genomic instability, as well as epigenetic silencing. Given the apparently opposing effects of Sp1, a more complete understanding of the function of Sp1 in cancer is required to validate its potential as a therapeutic target.

Polymorphisms in arachidonic acid metabolism-related genes and the risk and prognosis of colorectal cancer

Cyclooxygenase-2 (COX-2), 12-lipoxygenase (12-LOX) and phospholipaseA2 (PLA2) played important roles in the modulation of apoptosis, angiogenesis, carcinogenesis and invasion of colorectal cancer (CRC). The polymorphisms in COX-2, 12-LOX and PLA2 may affect their roles. Therefore, we investigated if COX-2 -1195G > A, 12-LOX 261Arg > Gln and PLA2 c.349 + 191A > G polymorphisms were associated with risk and prognosis of CRC as well as possible interactions with the environmental factors on the risk of CRC in Northeast of China. A case-control study with 451 cases and 631 controls were carried out, a cohort with 386 patients were followed up. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Compared with the 261Arg/Arg genotype, 12-LOX 261Arg/Gln genotype and 261Arg/Gln + Gln/Gln genotypes reduced the risk of rectal cancer by 33% (adjusted OR = 0.67, 95% CI 0.47-0.97, p = 0.03) and 32% (adjusted OR = 0.68, 95% CI 0.49-0.96, p = 0.03), respectively. The adjusted HR for the association between 12-LOX 261Gln/Gln genotype and overall survival in patients with CRC was 1.68 (95% CI 1.06-2.68, p = 0.03). There was also evidence of an interaction between the PLA2 c.349 + 191 A > G genotypes and the overnight food consumption (adjusted ORi = 1.92, 95% CI 1.14-3.25, P(interaction) = 0.01). These observations indicate that 12-LOX 261Arg > Gln polymorphism may affect risk of rectal cancer, and it may be a potential predictive marker for prognosis of CRC.

COX-1 (PTGS1) and COX-2 (PTGS2) polymorphisms, NSAID interactions, and risk of colon and rectal cancers in two independent populations

PURPOSE

Nonsteroidal anti-inflammatory drugs (NSAIDs) target the prostaglandin H synthase enzymes, cyclooxygenase (COX)-1 and COX-2, and reduce colorectal cancer risk. Genetic variation in the genes encoding these enzymes may be associated with changes in colon and rectal cancer risk and in NSAID efficacy.

METHODS

We genotyped candidate polymorphisms and tag SNPs in PTGS1 (COX-1) and PTGS2 (COX-2) in a population-based case–control study (Diet, Activity and Lifestyle Study, DALS) of colon cancer (n = 1,470 cases/1,837 controls) and rectal cancer (n = 583/775), and independently among cases and controls from the Colon Cancer Family Registry (CCFR; colon n = 959/1,535, rectal n = 505/839).

RESULTS

In PTGS2, a functional polymorphism (-765G[C; rs20417) was associated with a twofold increased rectal cancer risk (p = 0.05) in the DALS. This association replicated with a significant nearly fivefold increased risk of rectal cancer in the CCFR study (ORCC vs. GG = 4.88; 95 % CI 1.54–15.45; ORGC vs. GG = 1.36; 95 %CI 0.95–1.94). Genotype–NSAID interactions were observed in the DALS for PTGS1 and rectal cancer risk and for PTGS2 and colon cancer risk, but were no longer significant after correcting for multiple comparisons and did not replicate in the CCFR. No significant associations between PTGS1 polymorphisms and colon or rectal cancer risk were observed.

Genetic variation in prostaglandin synthesis and related pathways, NSAID use and colorectal cancer risk in the Colon Cancer Family Registry

Although use of non-steroidal anti-inflammatory drugs (NSAIDs) generally decreases colorectal cancer (CRC) risk, inherited genetic variation in inflammatory pathways may alter their potential as preventive agents. We investigated whether variation in prostaglandin synthesis and related pathways influences CRC risk in the Colon Cancer Family Registry by examining associations between 192 single nucleotide polymorphisms (SNPs) and two variable nucleotide tandem repeats (VNTRs) within 17 candidate genes and CRC risk. We further assessed interactions between these polymorphisms and NSAID use on CRC risk. Using a case-unaffected-sibling-control design, this study included 1621 primary invasive CRC cases and 2592 sibling controls among Caucasian men and women aged 18-90. After adjustment for multiple comparisons, two intronic SNPs were associated with rectal cancer risk: rs11571364 in ALOX12 [OR(het/hzv) = 1.87, 95% confidence interval (CI) = 1.19-2.95, P = 0.03] and rs45525634 in PTGER2 (OR(het/hzv) = 0.49, 95% CI = 0.29-0.82, P = 0.03). Additionally, there was an interaction between NSAID use and the intronic SNP rs2920421 in ALOX12 on risk of CRC (P = 0.03); among those with heterozygous genotypes, risk was reduced for current NSAID users compared with never or former users (OR(het) = 0.60, 95% CI = 0.45-0.80), though not among those with homozygous wild-type or variant genotypes. The results of this study suggest that genetic variation in ALOX12 and PTGER2 may affect the risk of rectal cancer. In addition, this study suggests plausible interactions between NSAID use and variants in ALOX12 on CRC risk. These results may aid in the development of genetically targeted cancer prevention strategies with NSAIDs.

Lack of association between cyclooxygenase 2-765G/C gene polymorphism and breast cancer risk in Ahvaz, west-south Iran

Cyclooxygenases are key enzymes in conversion of arachidonic acid into prostaglandin H2. Cyclooxygenase-2 (COX-2) increases prostaglandins in neoplastic tissue. COX-2 has important roles in cell proliferation cancers, angiogenesis, and alzheimer. COX-2 is up-regulated in several types of cancer, and it is hypothesized that COX-2 expression may be genetically influenced. Our main objective was to evaluated the association of polymorphism COX-2 with risk of breast cancer in khouzestan province, and the second objective of the study was to evaluate the association with biochemistry parameters. This study consisting of 150 patients with breast cancer and 120 normal DNA was extracted from the white blood cells. Polymorphism cox2 gene was detected by polymerase chain reaction according to the standard methods. The profile lipids and estrogen were measured in two groups by standard methods. Chi square analysis showed that there was no association between breast cancer risk and COX-2 -765G>C genotype and alleles. Also, no association were observed between -765G>C polymorphism and biochemistry parameters. A multiple logistic regression model with cox2 genotypes and LDL and HDL as covariates revealed that there is no significant association between cox2 genotypes and risk of breast cancer, but higher values of LDL and HDL significantly increase risk of breast cancer.

COX-2-765G>C polymorphism increases the risk of cancer: a meta-analysis

Background

Chronic inflammation has been regarded as an important mechanism in carcinogenesis. Inflammation-associated genetic variants have been highly associated with cancer risk. Polymorphisms in the gene cyclooxygenase-2 (COX-2), a pro-inflammation factor, have been suggested to alter the risk of multiple tumors, but the findings of various studies are not consistent.

Methods

A literature search through February 2013 was performed using PubMed, EMBASE, and CNKI databases. We used odds ratios (ORs) with confidence intervals (CIs) of 95% to assess the strength of the association between the COX-2-765G>C polymorphism and cancer risk in a random-effect model. We also assessed heterogeneity and publication bias.

Results

In total, 65 articles with 29,487 cancer cases and 39,212 non-cancer controls were included in this meta-analysis. The pooled OR (95% CIs) in the co-dominant model (GC vs. GG) was 1.11 (1.02–1.22), and in the dominant model ((CC+GC) vs. GG), the pooled OR was 1.12 (1.02–1.23). In the subgroup analysis, stratified by cancer type and race, significant associations were found between the-765 C allele and higher risk for gastric cancer, leukemia, pancreatic cancer, and cancer in the Asian population.

Conclusion

In summary, the COX-2-765 C allele was related to increased cancer susceptibility, especially gastric cancer and cancer in the Asian population.

A meta-analysis of PTGS1 and PTGS2 polymorphisms and NSAID intake on the risk of developing cancer

Background

Several studies have investigated whether the polymorphisms in the prostaglandin endoperoxide synthase 1 (PTGS1) and PTGS2 genes and nonsteroidal anti-inflammatory drug (NSAID) use are associated with cancer risk; however, those studies have produced mixed results. Therefore, we performed a meta-analysis to evaluate the association between the PTGS1 and PTGS2 polymorphisms and the effect of NSAID use on the risk of developing cancer.

Methods

We conducted a comprehensive search in PubMed through March 2012. The odds ratios (ORs) with the corresponding 95% confidence intervals (CIs) were calculated using the fixed-effect model or the random-effect model.

Results

The database search generated 13 studies that met the inclusion criteria. For PTGS1 rs3842787, NSAID users homozygous for the major allele (CC) had a significantly decreased cancer risk compared with non-NSAID users (OR = 0.73, 95% CI = 0.59–0.89). For PTGS2 rs5275 and rs20417, there were no significant differences between the gene polymorphism and NSAID use on cancer risk among the 8 and 7 studies, respectively. However, in the stratified analysis by the type of cancer or ethnicity population, NSAID users homozygous for the major allele (TT) in rs5275 demonstrated significantly decreased cancer risk compared with non-NSAID users in cancer type not involving colorectal adenoma (OR = 0.70, 95% CI = 0.59–0.83) and among the USA population (OR = 0.67, 95% CI = 0.56–0.82). NSAID users homozygous for the major allele (GG) in rs20417 displayed a significantly decreased cancer risk than non-NSAID users among the US population (OR = 0.72, 95% CI = 0.58–0.88). For the PTGS2 rs689466 and rs2745557 SNPs, there were no significant differences.

Conclusion

This meta-analysis suggests that the associations between PTGS polymorphisms and NSAID use on cancer risk may differ with regard to the type of cancer and nationality.

Genetic variation in the lipoxygenase pathway and risk of colorectal neoplasia

Arachidonate lipoxygenase (ALOX) enzymes metabolize arachidonic acid to generate potent inflammatory mediators and play an important role in inflammation-associated diseases. We investigated associations between colorectal cancer risk and polymorphisms in ALOX5, FLAP, ALOX12, and ALOX15, and their interactions with nonsteroidal anti-inflammatory drug (NSAID) use. We genotyped fifty tagSNPs, one candidate SNP, and two functional promoter variable nucleotide tandem repeat (VNTR) polymorphisms in three US population-based case-control studies of colon cancer (1,424 cases/1,780 controls), rectal cancer (583 cases/775 controls), and colorectal adenomas (485 cases/578 controls). Individuals with variant genotypes of the ALOX5 VNTR had a decreased risk of rectal cancer, with the strongest association seen for individuals with one or more alleles of >5 repeats (wild type = 5, OR>5/≥5 = 0.42, 95% CI 0.20-0.92; P = 0.01). Four SNPs in FLAP (rs17239025), ALOX12 (rs2073438), and ALOX15 (rs4796535 and rs2619112) were associated with rectal cancer risk at P ≤ 0.05. One SNP in FLAP (rs12429692) was associated with adenoma risk. A false discovery rate (FDR) was applied to account for false positives due to multiple testing; the ALOX15 associations were noteworthy at 25% FDR. Colorectal neoplasia risk appeared to be modified by NSAID use in individuals with variant alleles in FLAP and ALOX15. One noteworthy interaction (25% FDR) was observed for rectal cancer. Genetic variability in ALOXs may affect risk of colorectal neoplasia, particularly for rectal cancer. Additionally, genetic variability in FLAP and ALOX15 may modify the protective effect of NSAID use against colorectal neoplasia.

IκBKβ and NFκB1, NSAID use and risk of colorectal cancer in the Colon Cancer Family Registry

The NFκB-signaling pathway regulates cell proliferation and inflammation. Activation of the pathway is implicated in the etiology of colorectal cancer (CRC). NSAIDs may reduce CRC risk partially through a nuclear factor-kappa B (NFκB)-dependent pathway. In this study, we investigated associations between 34 NFκB1 and 8 IκBKβ tagSNPs and CRC risk and examined interactions with non-steroidal anti-inflammatory drug (NSAID) use. Using conditional logistic regression, we investigated these associations among 1584 incident CRC cases and 2516 sibling controls from the Colon Cancer Family Registry. Three IκBKβ SNPs were associated with a statistically significant lower colorectal or colon cancer risk: rs9694958 (A>G intron 5) (colorectal: OR(hzv) = 0.26(0.07-0.99), P(trend) = 0.048, P(adj) = 0.25), rs10958713 (A>C intron 19) (colon: OR(hzv) = 0.62(0.42-0.92), P(trend) = 0.005, P(adj) = 0.03) and rs5029748 (C>A intron 2) (colon: OR(het) = 0.72(0.56-0.91), P(trend) = 0.01, P(adj) = 0.08). We replicated trends associated with NFκB1 and IκBKβ variants identified in a previous study (rs4648110 (T>A intron 22), rs13117745 (G>A intron 5) and rs3747811 (T>A intron 1)). IκBKβ's rs6474387 (C>T intron 20) and rs11986055 (A>C intron 2) showed substantially lower colon cancer risk among current NSAID users (P(interaction) = 0.01 and P(interaction) = 0.045, respectively), whereas NFκB1's rs230490 (G>A 5' (outside UTR)) and rs997476 (C>A 3' (outside UTR)) showed higher CRC risk among current NSAID users (P(interaction) = 0.01 and P(interaction) = 0.03, respectively). These findings suggest that variants in NFκB1 and IκBKβ are associated with CRC risk and NSAIDs may function partially through an NFκB-dependent pathway. The SNPs identified here should be considered for future functional studies and may be useful in designing a pharmacogenetic approach to preventive NSAID use.

The connection between lymphangiogenic signalling and prostaglandin biology: a missing link in the metastatic pathway

Substantial evidence supports important independent roles for lymphangiogenic growth factor signaling and prostaglandins in the metastatic spread of cancer. The significance of the lymphangiogenic growth factors, vascular endothelial growth factor (VEGF)-C and VEGF-D, is well established in animal models of metastasis, and a strong correlation exits between an increase in expression of VEGF-C and VEGF-D, and metastatic spread in various solid human cancers. Similarly, key enzymes that control the production of prostaglandins, cyclooxygenases (COX-1 and COX-2, prototypic targets of Non-steroidal anti-inflammatory drugs (NSAIDs)), are frequently over-expressed or de-regulated in the progression of cancer. Recent data have suggested an intersection of lymphangiogenic growth factor signaling and the prostaglandin pathways in the control of metastatic spread via the lymphatic vasculature. Furthermore, this correlates with current clinical data showing that some NSAIDs enhance the survival of cancer patients through reducing metastasis. Here, we discuss the potential biochemical and cellular basis for such anti-cancer effects of NSAIDs through the prostaglandin and VEGF signaling pathways.

PTGS1, PTGS2, ALOX5, ALOX12, ALOX15, and FLAP SNPs: interaction with fatty acids in colon cancer and rectal cancer

Dietary polyunsaturated fatty acids (PUFAs) can be converted to prostaglandins and leukotrienes. Oxygenation of omega-6 PUFAs generally results in the production of pro-inflammatory mediators, whereas oxygenated products of omega-3 (n-3) PUFAs generally have lower inflammatory activity. We hypothesize that elevated n-3 PUFA intakes from fish are associated with lower risk of colorectal cancer among those with genetic variants that result in higher levels of pro-inflammatory mediators. In population-based case-control studies of colon (case n = 1,574) and rectal cancer (case n = 791) and disease-free controls (n = 2,969), we investigated interactions between dietary fatty acid intake and 107 candidate polymorphisms and tagSNPs in PTGS1, PTGS2, ALOX12, ALOX5, ALOX15, and FLAP. The two studies used an identical genotyping protocol. We observed interactions and statistically significant increases in colon cancer risk for low docosahexaenoic acid intake among those with the PTGS1 rs10306110 (-1,053 A > G) variant genotypes (OR = 1.6, 95 % confidence interval = 1.1-2.3, adj. p = 0.06) and rectal cancer risk for low total fat intake among those with the variant PTGS1 rs10306122 (7,135 A > G) (OR(vs.wt) = 1.80, 1.02-2.99; adj. p = 0.08). The ALOX15 rs11568131 (10,339 C > T) wild type in combination with a high inflammation score (low EPA intake, high AA intake, no regular NSAID use, high BMI, smoking) was associated with increased colon cancer risk (OR = 2.28, 1.7-3.07). Rectal cancer risk was inversely associated with a low inflammation score among PTGS2 rs4648276 (3,934 T > C) variant allele carriers (OR = 0.49, 0.25-0.75). Overall, these data provide some modest evidence for interactions between dietary fat intake and genetic variation in genes involved in eicosanoid metabolism and colorectal cancer risk.

A study of prostaglandin pathway genes and interactions with current nonsteroidal anti-inflammatory drug use in colorectal adenoma

Colorectal cancer (CRC) is the second leading cause of cancer-related death and usually arises from colorectal polyps. Screening and removal of polyps reduce mortality from CRC. Colorectal polyps are known to aggregate in families; however the genetic determinants for risk of polyps are unknown. In addition, it has been shown that nonsteroidal anti-inflammatory drug (NSAID) use decreases the risk of CRC and the incidence and size of polyps. In this study, we used data from the Tennessee Colorectal Polyp Study and the Tennessee-Indiana Adenoma Recurrence Study to evaluate selected genes from the prostaglandin (PG) metabolism and signaling pathways for association with risk of polyps and for interactions with NSAIDs. Our design consisted of discovery and replication phases for a total of 2,551 Caucasian polyp cases and 3,285 Caucasian controls. We carried out multivariable logistic regression to test for association in both the discovery and replication phase and further examined the results with meta-analysis. We detected association signals in the genes PGE receptor 3 (PTGER3) and 15-hydroxyprostaglandin dehydrogenase (HPGD), both strong biologic candidates for influence on polyp risk. We did not observe the previously reported effects and effect modification in PG-endoperoxide synthase 2 (PTGS2), PGE receptor 2 (PTGER2), or PGE receptor 4 (PTGER4), although we did observe a single nucleotide polymorphism in PTGER2 associated with risk of multiple adenomas. We also observed effect modification of the HPGD signal by NSAID exposure.

The risk of coronary thrombosis with cyclo-oxygenase-2 inhibitors does not vary with polymorphisms in two regions of the cyclo-oxygenase-2 gene

AIMS

To investigate whether polymorphisms of the cyclo-oxygenase-2 (COX-2) gene modify the adverse cardiovascular effects of COX-2 inhibitors.

METHODS

A case control study was conducted in the Hunter Region of New South Wales, Australia. Cases (n= 460) were hospitalized with acute coronary syndrome (ACS). Controls (n= 640) were recruited from the electoral rolls. Structured interviews gathered information on variables including recent ingestion of non-steroidal anti-inflammatory drugs (NSAIDs). Targeted genotyping of rs 20417(G > C) and rs5275 (T > C) polymorphisms was performed by real-time polymerase chain reaction using allele-specific probes.

RESULTS

Ingestion of any NSAID in the week prior to interview was associated with an elevated risk for ACS: adjusted odds ratio 1.8 (1.2, 2.5). The rs 20417 and rs 5275 polymorphisms were not singly associated with risk for ACS: adjusted odds ratios 1.1 (0.80, 1.5) and 1.2 (0.88, 1.5), respectively. Individually, the polymorphisms did not modify the risk of ACS with the drugs. When analyses were conducted by haplotype, the adjusted odds ratio with celecoxib or rofecoxib in individuals who had one or two copies of the 'low risk' haplotype (no GT) was 1.2 (0.29, 5.0), compared with 2.1 (1.1, 4.0) with the 'high risk' haplotype (one or two copies of GT).

CONCLUSIONS

We found little evidence of a gene/drug interaction. We found a statistically non-significant trend toward a lower risk of coronary events with NSAIDs in the presence of the 'low risk' haplotype. Even if confirmed, the clinical utility of the finding would be limited as this haplotype is carried by a minority of the population.

Linkage disequilibrium and haplotype analysis of COX-2 and risk of colorectal adenoma development

Single nucleotide polymorphisms (SNPs) in the promoter and untranslated region of cyclooxygenase (COX)-2, an inducible enzyme responsible for the synthesis of prostaglandins, have been reported to modulate the risk for many human cancers. We performed comprehensive linkage disequilibrium (LD) and haplotype analyses of 13 single nucleotide polymorphisms of the COX-2 gene and examined its susceptibility to adenoma development in 72 African American cases and 142 controls. Results revealed significant variation in LD patterns with consequence for adenoma development. Two distinct haplotype blocks were identified; one block covered the coding regions of exon 1, introns and a section of the 3'-unstranslated region (3'-UTR), whereas the second block resided solely in the 3'-UTR region. A haplotype in block 1 increased the risk of adenoma development by threefold (odds ratio [OR]= 2.9, confidence interval [CI]= 1.8-3.7, P= 0.002). Regression analysis showed, increase in copies of minor alleles of 6,064(T>C) polymorphism associated with increased odds of adenoma development by 80% (OR = 1.80, CI = 1.09-3.21, P= 0.034), 10,848(G>A) by 84% (OR = 1.84, CI = 1.05-3.23, P= 0.034) and 10,935(A>G) by 32% (OR = 1.32, CI = 1.12-3.69, P= 0.036). These results support the hypothesis that COX-2 gene might play a role in the etiology of colon cancer and warrant further investigation in other cancers. Besides, these variations should be taken into account for disease-based association studies in which the COX-2 polymorphism is considered as a candidate gene. Clin Trans Sci 2012; Volume 5: 60-64.

PTGS2 (COX2) -765G>C gene polymorphism and risk of sporadic colorectal cancer in Iranian population

Colorectal cancer (CRC) is one of the leading cancers worldwide. Through genome wide association studies, several single nucleotide polymorphisms scattered in the genome emerged to be influential in the development of sporadic CRC in some populations. However, replicative studies failed to prove a particular SNP-CRC association in populations and ethnic groups. Cyclooxygenase-2 (PTGS2) is a crucial enzyme involved in the metabolism of prostaglandins. The aim of this replicative study is to investigate the possible association between PTGS2 -765G>C polymorphism and sporadic CRC risk in a subset of Iranian population. A total of 110 patients with sporadic CRC, and 120 controls were genotyped for PTGS2 -765G>C polymorphism by using polymerase chain reaction-based restriction fragment length polymorphism. There were no significant differences in the genotype and allele frequencies of PTGS2 -765G>C between two groups except in irregular aspirin or non-steroidal anti-inflammatory drugs (NSAID) consumers. Frequencies of genotypes and alleles were as follows: GG = 44.2, GC = 48.3, CC = 7.5%, in controls and GG = 34.55, GC = 60.9, CC = 4.55% in cases. Regarding the allele frequency, the following values were found: G = 65, C = 35% in cases and 68.3, 31.7% in the controls, respectively. In irregular aspirin or NSAID consumers combined GC+CC genotype was found to be a risk genotype (OR = 1.933, 95% CI: 1.067-3.501, P = 0.036). Overall, no significant relation was found between this polymorphism and sporadic CRC in Iranians. However, in irregular aspirin or NSAID consumers the combined GC+CC genotype proved to be a risk genotype.

Polymorphisms in cycloxygenase-2 gene and breast cancer prognosis: association between PTGS2 haplotypes and histopathological features

Cyclooxygenase-2 (COX-2) overexpression is associated with worse prognosis in breast cancer. COX-2 is encoded by a polymorphic gene, called PTGS2, and its expression may be genetically influenced. In this article, we investigate the association between PTGS2 haplotypes and histopathological parameters with prognostic value on the clinical outcome of breast cancer. The study involved 606 women under current treatment for non-metastatic breast cancer. Patients were genotyped for rs689465, rs689466, rs20417, and rs5275, and their haplotypes were inferred. The distribution of PTGS2 genotypes and haplotypes was evaluated according to histopathological categorical groups used for prognostic determination of low/intermediate versus high risk of tumor recurrence. Our results indicate positive associations between variant genotypes of rs689465 and estrogen receptor negativity (OR: 1.59, 95% CI: 1.04-2.44, P: 0.02) or HER2 positivity (OR: 1.79, 95% CI: 1.00-3.18, P: 0.03), and between variant genotypes of rs20417 and estrogen receptor negativity (OR: 1.75, 95% CI: 1.15-2.57, P: 0.005), progesterone receptor negativity (OR: 1.56, 95% CI: 1.09-2.22, P: 0.01) or HER2 positivity (OR: 1.80, 95% CI: 1.04-3.13, P: 0.02). In contrast, variant genotypes of rs689466 are negatively associated with estrogen receptor negativity (OR: 0.57, 95% CI: 0.33-0.98, P: 0.03). A total of eight haplotypes were inferred, and there was a significant difference in their distribution as a function of tumor size (P: 0.011), estrogen receptor status (P: 0.018), and HER2 status (P: 0.025). PTGS2 haplotype *7 (formed by rs689465G, rs689466A, rs20417C, and rs5275T) is positively associated with higher tumor size (OR: 3.72, 95% CI: 1.19-11.22, P: 0.006), estrogen receptor negativity (OR: 2.43, 95% CI: 0.97-5.98, P: 0.032), progesterone receptor negativity (OR: 2.58, 95% CI: 1.05-6.39, P: 0.02), and HER2 positivity (OR: 4.17, 95% CI: 1.19-14.44, P: 0.007). Our results suggest that PTGS2 haplotype *7 may contribute to higher growth of untreated breast cancer and that PTGS2 haplotypes need to be considered in the characterization of breast cancer prognosis.

Cyclooxygenase-2 (COX-2) polymorphisms and risk of inflammatory bowel disease in a Scottish and Danish case-control study

BACKGROUND

Inflammatory bowel diseases (IBDs) are a result of interactions between luminal pathogens and the intestinal immune response. Cyclooxygenase-2 (COX-2) plays a key role in the regulation of the inflammatory response upon stimulation by luminal pathogens via Toll-like receptors.

METHODS

Genotypes of the COX-2/PTGS2/PGHS2 A-1195G (rs689466), G-765C (rs20417), and T8473C (rs5275) polymorphisms were assessed in a Scottish and Danish case-control study including 732 Crohn's disease (CD) cases, 973 ulcerative colitis (UC) cases, and 1157 healthy controls using logistic regression.

RESULTS

Carriers of the COX-2 A-1195G variant allele had increased risk of UC (odds ratio [OR], 95% confidence interval [CI] = 1.25 [1.02-1.54], P = 0.03) and of both UC and IBD among never smokers (OR [95% CI] = 1.47 [1.11-1.96], P = 0.01 and OR [95% CI] = 1.37 [1.06-1.77], P = 0.02, respectively). Furthermore, this variant genotype was associated with increased risk of diagnosis of UC before age 40 years and with extensive UC (OR [95% CI] = 1.34 [1.11-1.62], P = 0.002 and OR [95% CI] = 1.32 [1.03-1.69], P = 0.03, respectively).

CONCLUSIONS

COX-2 A-1195G polymorphism was associated with the risk of UC, especially among never-smokers, suggesting that low activity of COX-2 may predispose to UC. Our results suggest that inclusion of smoking status may be essential for the evaluation of the role of genetic predisposition to IBD.

Non-steroidal anti-inflammatory drug use and colorectal polyps in the Prostate, Lung, Colorectal, And Ovarian Cancer Screening Trial

OBJECTIVES

Non-steroidal anti-inflammatory drugs (NSAIDs) have been documented in animal and human studies to reduce risk for colorectal cancer and adenomatous polyps, but risk modification for subgroups of the population and effects on hyperplastic polyps have been less studied.

METHODS

Data on recent use of two frequently ingested NSAIDs, aspirin and ibuprofen, were collected at baseline from participants aged 55-74 years in the 10 centers of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO). Participants randomized to the intervention arm of the trial received a flexible sigmoidoscopy during a baseline examination. Follow-up of detected polyps was accomplished outside the Trial setting and relevant records were sought and abstracted. Cases (n=4,017) included subjects with a biopsy-proven polyp in the left side of the colon (descending colon, sigmoid, and rectum) detected as a consequence of PLCO screening; controls (n=38,396) were subjects with no left-sided colon polyp.

RESULTS

Regular use of aspirin (≥ 4 times/month) in the past year was inversely associated with hyperplastic polyps (odds ratios (OR)=0.8, 95% confidence interval (CI)=0.7-0.9), adenomatous polyps (OR=0.8, 95% CI=0.8-0.9), and advanced adenomas (OR=0.8, 95% CI=0.7-0.9). As frequency of aspirin use increased, the prevalence of polyps decreased significantly for each histological classification (P for trend ≤ 0.0004). Similar patterns were found for adenomas and ibuprofen. Overall protection was consistent in both the descending colon or sigmoid and the rectum, but more evident in males. In males, the OR for heavy use of combined aspirin and ibuprofen (≥ 2 times/day) was 0.6 (95% CI=0.5-0.8), as opposed to 0.9 (95% CI=0.8-1.1) in females. The protective effects of NSAIDs for females were apparent only among those with body mass index (BMI) <25 (OR=0.8, 95% CI=0.7-1.0 for regular use of NSAIDs; P interaction=0.04). We also found a slightly stronger protection of NSAIDs in the 70-74 years age group compared with those aged 55-69 years.

CONCLUSIONS

This study of a large general risk population supports previous work that recent use of aspirin and ibuprofen is associated with a decreased risk of colorectal adenomas and demonstrates that this protective effect may be stronger in certain population subgroups and is also evident for aspirin and hyperplastic polyps.

Cyclooxygenase-2 gene and epithelial ovarian carcinoma risk

In this study, we aimed to investigate a possible association of the COX-2 polymorphisms (-765G→C and -1195A→G) and with the risk of developing epithelial ovarian carcinoma (EOC). COX-2 gene polymorphisms was investigated in 111 healthy women and 57 patients with EOC. Individuals who had -765 CG, -1195 AA genotype, and -765 C allele had increased risk for ovarian carcinoma (P < 0.01) and individuals with -765 GG, -1195 AG genotypes and -1195 G allele seem to be protected from ovarian carcinoma (P < 0.01). Haplotype analysis confirmed the association of COX-2 gene variants with ovarian carcinoma and revealed that the frequencies of -765C: -1195A haplotype frequencies was significantly higher in patients as compared with those of controls (P = 0.048). We state that there appears to be a modulating role for the COX-2 -1195A→G and -765G→C polymorphisms in the development of EOC. To the best of our knowledge, this is the first study to show such an association.

Polymorphisms in regulatory regions of cyclooxygenase-2 gene and breast cancer risk in Brazilians: a case-control study

Background

Cyclooxygenase-2 (COX-2) is up-regulated in several types of cancer, and it is hypothesized that COX-2 expression may be genetically influenced. Here, we evaluate the association between single-nucleotide polymorphisms (SNPs) in the COX-2 gene (PTGS2) and the occurrence of breast cancer among Brazilian women.

Methods

The study was conducted prospectively in two steps: First, we screened the promoter region and three fragments of the 3'-untranslated region of PTGS2 from 67 healthy Brazilians to identify SNPs and to select those with a minor allele frequency (MAF) of at least 0.10. The MAF of these selected SNPs was further characterized in 402 healthy volunteers to evaluate potential differences related to heterogeneous racial admixture and to estimate the existence of linkage disequilibrium among the SNPs. The second step was a case-control study with 318 patients and 273 controls designed to evaluate PTGS2 genotype- or haplotype-associated risk of breast cancer.

Results

The screening analysis indicated nine SNPs with the following MAFs: rs689465 (0.22), rs689466 (0.15), rs20415 (0.007), rs20417 (0.32), rs20419 (0.015), rs5270 (0.02), rs20424 (0.007), rs5275 (0.22) and rs4648298 (0.01). The SNPs rs689465, rs689466, rs20417 and rs5275 were further studied: Their genotypic distributions followed Hardy-Weinberg equilibrium and the MAFs were not affected by gender or skin color. Strong linkage disequilibrium was detected for rs689465, rs20417 and rs5275 in the three possible pairwise combinations. In the case-control study, there was a significant increase of rs5275TC heterozygotes in cases compared to controls (OR = 1.44, 95% CI = 1.01-2.06; P = 0.043), and the haplotype formed by rs689465G, rs689466A, rs20417G and rs5275C was only detected in cases. The apparent association with breast cancer was not confirmed for rs5275CC homozygotes or for the most frequent rs5275C-containing haplotypes.

Conclusions

Our results indicate no strong association between the four most frequent PTGS2 SNPs and the risk of breast cancer.

Use of aspirin and other nonsteroidal antiinflammatory medications in relation to prostate cancer risk

Recent interest has focused on the role that inflammation may play in the development of prostate cancer and whether use of aspirin or other nonsteroidal antiinflammatory drugs (NSAIDs) affects risk. In a population-based case-control study designed to investigate the relation between these medications and prostate cancer risk, detailed exposure data were analyzed from 1,001 cases diagnosed with prostate cancer between January 1, 2002, and December 31, 2005, and 942 age-matched controls from King County, Washington. A significant 21% reduction in the risk of prostate cancer was observed among current users of aspirin compared with nonusers (95% confidence interval (CI): 0.65, 0.96). Long-term use of aspirin (>5 years: odds ratio = 0.76, 95% CI: 0.61, 0.96) and daily use of low-dose aspirin (odds ratio = 0.71, 95% CI: 0.56, 0.90) were also associated with decreased risk. There was no evidence that the association with aspirin use varied by disease aggressiveness, but there was effect modification (P(interaction) = 0.02) with a genetic variant in prostaglandin-endoperoxide synthase 2 (PTGS2) (rs12042763). Prostate cancer risk was not related to use of either nonaspirin NSAIDs or acetaminophen. These results contribute further evidence that aspirin may have chemopreventive activity against prostate cancer and highlight the need for additional research.

The cyclooxygenase-2-765C promoter polymorphism protects against the development of chronic obstructive pulmonary disease

BACKGROUND

Susceptibility to Chronic Obstructive Pulmonary Disease (COPD) has a genetic component. We undertook a study to determine if a genetic variant of the gene encoding the cyclooxygenase-2 gene influences the likelihood of developing COPD.

METHODS

In a case control study the frequency of a single nucleotide polymorphism in the promoter region of the cyclooxygenase-2 gene (-765 G → C) was determined in 205 subjects with COPD, 171 chronic smokers with normal lung function (resistant smokers) and 95 healthy blood donors using the polymerase chain reaction and restriction enzyme fragment length polymorphism.

RESULTS

The frequency of the C allele of the -765 cyclooxygenase-2 polymorphism was higher in resistant smokers (24.6%) compared with subjects with COPD (14.4%, OR = 1.98, 95% CI = 1.28-3.06, p = 0.003) and blood donors (14.7%, OR = 1.97, 95% CI = 1.14-3.41, p = 0.03).

CONCLUSIONS

The -765C allele, which has been shown to be associated with decreased promoter activity of the cyclooxygenase-2 gene, is more common in resistant smokers. This raises the possibility that decreased activity of cyclooxygenase-2 may protect smokers against the development of COPD.

Cyclooxygenase-2 gene and lung carcinoma risk

In this study, we aimed to investigate a possible association of the COX-2 polymorphisms with the risk of developing lung carcinoma. COX-2 (-765G→C; -1195A→G) gene polymorphisms were performed by polymerase chain reaction (PCR) and restriction fragment length polymorphism in 118 healthy individuals and 231 patients with lung carcinoma. The present study was the first that addressed the role of the COX-2-765G→C and -1195A→G polymorphisms in lung carcinoma in Turkish population. In the present study, we found that the frequencies of GG, CC, and CG genotypes of COX-2-765G→C and AA, GG, and AG genotypes of -1195A→G in our control group were 0.22, 0.22, 0.55 and 0.59, 0.0, 0.40, respectively. These frequencies in patient group were 0.34, 0.07, 0.58 and 0.74, 0.04, 0.24, respectively. There were statistically significant differences in COX-2-765G→C (P=0.0002) and -1195A→G genotypes (P=0.007) between the controls and patients. We found that individuals carrying -765 GG genotype and -765 G allele of COX-2 or 1195 AA genotype of COX-2 and -765G: -1195A haplotype had an increased risk for the development of lung carcinoma. In contrast, individuals with -765 CC, -1195 AG genotypes and -1195 G allele of COX-2 seem to be protective from lung carcinoma. We suggest that the COX-2-765G→C and -1195A→G genotypes may be a risk factor for lung carcinoma.

Association of -765G>C polymorphism of the COX-2 gene with recurrent embryo implantation failure in Southern Chilean women

BACKGROUND

Embryo implantation failure is considered an important cause of infertility in women undergoing assisted reproductive protocols. Recent studies demonstrated that the cyclooxygenase-2 (COX-2) enzyme is implicated in biosynthesis of prostaglandins and play an important role in the molecular implantation mechanisms. According to this evidence, we evaluated the potential association between the -765G>C (rs20417) polymorphism at the COX-2 gene and the implantation failure susceptibility in a sample of Chilean women.

METHODS

A total of 186 unrelated women matched by age were included in the present study, 106 patients (aged 31.9±4.17 y) with no history of successful pregnancy and a diagnosis of infertility undergoing assisted reproductive protocols and 80 healthy controls (aged 31.4 ± 4.05 y). The COX-2 -765G>C gene polymorphism was analyzed by PCR-RFLP.

RESULTS

Genotype distribution and allelic frequencies for -765G>C polymorphism of COX-2 gene were significantly different between patients and controls (P=0.004 and P=0.002, respectively). The odds ratio for implantation failure associated to the -765C allelic variant was 2.14 (95% C.I., 1.35-3.39, P=0.00071).

CONCLUSION

Our data suggest, by the first time, that the COX-2 -765G>C polymorphism is associated with recurrent implantation failure in Chilean women and may constituted a novel molecular biomarker of reproductive failure.

Polymorphic human prostaglandin H synthase-2 proteins and their interactions with cyclooxygenase substrates and inhibitors

The cyclooxygenase (COX) activity of prostaglandin H synthase-2 (PGHS-2) is implicated in colorectal cancer and is targeted by nonsteroidal anti-inflammatory drugs (NSAIDs) and dietary n-3 fatty acids. We used purified, recombinant proteins to evaluate the functional impacts of the R228H, E488G, V511A and G587R PGHS-2 polymorphisms on COX activity, fatty acid selectivity and NSAID actions. Compared to wild-type PGHS-2, COX activity with arachidonate was ∼20% lower in 488G and ∼20% higher in 511A. All variants showed time-dependent inhibition by the COX-2-specific inhibitor (coxib) nimesulide, but 488G and 511A had 30-60% higher residual COX activity; 511A also showed up to 70% higher residual activity with other time-dependent inhibitors. In addition, 488G and 511A differed significantly from wild type in Vmax values with the two fatty acids: 488G showed ∼20% less and 511A showed ∼20% more discrimination against eicosapentaenoic acid. The Vmax value for eicosapentaenoate was not affected in 228H or 587R, nor were the Km values or the COX activation efficiency (with arachidonate) significantly altered in any variant. Thus, the E488G and V511A PGHS-2 polymorphisms may predict who will most likely benefit from interventions with some NSAIDs or n-3 fatty acids.

Genetic variation in prostaglandin E2 synthesis and signaling, prostaglandin dehydrogenase, and the risk of colorectal adenoma

BACKGROUND

Prostaglandins are important inflammatory mediators; prostaglandin E2 (PGE2) is the predominant prostaglandin in colorectal neoplasia and affects colorectal carcinogenesis. Prostaglandins are metabolites of omega-6 and omega-3 polyunsaturated fatty acids; their biosynthesis is the primary target of nonsteroidal anti-inflammatory drugs (NSAID), which reduce colorectal neoplasia risk.

METHODS

We investigated candidate and tagSNPs in PGE2 synthase (PGES), PGE2 receptors (EP2 and EP4), and prostaglandin dehydrogenase (PGDH) in a case-control study of adenomas (n = 483) versus polyp-free controls (n = 582) and examined interactions with NSAID use or fish intake, a source of omega-3 fatty acids.

RESULTS

A 30% adenoma risk reduction was observed for EP2 4950G>A (intron 1; OR(GA/AA vs. GG), 0.71; 95% confidence interval, 0.52-0.99). For the candidate polymorphism EP4 Val294Ile, increasing fish intake was associated with increased adenoma risk among those with variant genotypes, but not among those with the Val/Val genotype (P(interaction) = 0.02). An interaction with fish intake was also observed for PGES -664A>T (5' untranslated region; P(interaction) = 0.01). Decreased risk with increasing fish intake was only seen among those with the AT or TT genotypes (OR(>2 t/wk vs. <1 t/wk), 0.56; 95% confidence interval, 0.28-1.13). We also detected interactions between NSAIDs and EP2 9814C>A (intron 1) and PGDH 343C>A (intron 1). However, none of the observed associations was statistically significant after adjustment for multiple testing. We investigated potential gene-gene interactions using the Chatterjee 1 degree of freedom Tukey test and logic regression; neither method detected significant interactions.

CONCLUSIONS

These data provide little support for associations between adenoma risk and genetic variability related to PGE(2), yet suggest gene-environment interactions with anti-inflammatory exposures.