Cyclooxygenase-2 gene and lung carcinoma risk

Sex-dependent interaction of PTGS2 with miR-146a as risk factor for melanoma and the impact of sex hormones in gene expression in skin cells

Gender disparity in melanoma is a complex issue where sex hormones could be engaged. Differences in genetic variations are important in understanding the mechanisms of sex disparity in melanoma. Post-transcriptional regulation of prostaglandin-endoperoxide synthase (PTGS2) mRNA occurs through a complex interplay of specific trans-acting RNA-binding proteins and microRNAs. MiR-146a is a key player in melanoma, modulating immune responses and tumor microenvironment (TME). Polymorphisms in PTGS2 gene rs20415GC have been associated with an increased risk of melanoma. Epistasis between polymorphisms rs20415GC was investigated by genotyping 453 melanoma patients and 382 control individuals. The effects of testosterone and 17β-estradiol were analyzed in keratinocytes and two melanoma cell lines. The rs2910164GG showed a higher risk in the presence of the genotype rs20417CC in the male population. Testosterone and 17β-estradiol act differently on PTGS2 and miR-146a expression, depending on the cell type. Testosterone augments PTGS2 gene expression in keratinocytes and miR-146a in melanoma cells. While 17β-estradiol only increases miR-146a expression in HaCaT cells. The present study indicates a sex-specific relation between miR-146a and PTGS2 polymorphisms with melanoma cancer risk. Testosterone and 17β-estradiol act differently on the expression of PTGS2 and miR-146a depending on the skin cell type.

The Association Between Cyclooxygenase-2 -1195G/A (rs689466) Gene Polymorphism and the Clinicopathology of Lung Cancer in the Japanese Population: A Case-Controlled Study

The single nucleotide polymorphisms of COX-2 gene, also known as PTGS2, which encodes a pro-inflammatory factor cyclooxygenase-2, alter the risk of developing multiple tumors, but these findings are not consistent for lung cancer. We previously reported that the homozygous COX-2 –1195A genotype is associated with an increased risk for chronic obstructive pulmonary disease (COPD) in Japanese individuals. COPD is a significant risk factor for lung cancer due to genetic susceptibility to cigarette smoke. In this study, we investigated the association between COX-2 –1195G/A polymorphism and lung cancer susceptibility in the Japanese population. We evaluated the genotype distribution of COX-2 –1195G/A using a polymerase chain reaction-restriction fragment length polymorphism assay for 330 newly diagnosed patients with lung cancer and 162 healthy controls. Our results show that no relationship exists between the COX-2 –1195G/A polymorphism and the risk of developing lung cancer. However, compared to the control group, the homozygous COX-2 –1195A genotype increased the risk for lung squamous cell carcinoma (odds ratio = 2.902; 95% confidence interval, 1.171–7.195; p = 0.021), whereas no association is observed with the risk for adenocarcinoma. In addition, Kaplan-Meier analysis shows that the genotype distribution of homozygous COX-2 –1195A does not correlate with the overall survival of patients with lung squamous cell carcinoma. Thus, we conclude that the homozygous COX-2 –1195A genotype confers an increased risk for lung squamous cell carcinoma in Japanese individuals and could be used as a predictive factor for early detection of lung squamous cell carcinoma.

Genetic variant in the 3'-untranslated region of the COX2 gene is associated with type 2 diabetes: A hospital-based case-control study

Type 2 diabetes (T2DM) is caused by the decreased β-cell mass and insulin deficiency, and disease is characterized by hypoglycemia. The insulin resistance also plays an important role in T2DM pathogenesis. Insulin resistance is the reduced biological response to insulin at the normal concentration in the circulation and develops with the influence of environmental factors with genetic abnormalities. In recent years, it has been reported that inflammatory pathway causes activation of the insulin resistance. Chronic inflammation inhibits the insulin sensitivity through activation of signaling pathways which are directly associated with the key components of insulin signaling pathway. Cyclooxygenase (COX) enzymes are key enzymes that catalysis prostaglandin synthesis from arachidonic acid. COX2 is an inducible COX isoform and that plays an important role in inflammatory process by leading the synthesis of pro- and anti- inflammatory prostaglandins. In our study, we aimed to investigate the relationship between variants of COX-2 gene which is one of the key components of the inflammatory pathway, and T2DM risks. In this study, we evaluated rs5275 and rs689466 variants located on the COX-2 gene by PCR-RFLP in 100 T2DM patients and 100 control subjects. The interaction among COX2 variants and T2DM was analyzed using appropriate methods. The both variants were in Hardy-Weinberg equilibrium in patients and controls (p > 0.05). A significant association was observed for genotype distribution of COX2 rs5275 site between control and T2DM cases (p = 0.042). In a dominant model, the cases who had at least one copy of allele C, were at increased risk of T2DM (p = 0.016). We found no significant association for the COX2 rs689466 domain by evaluating homozygous, heterozygous, dominant, and recessive models (p > 0.05). According to our data, the rs5275 variant of the COX2 in the 3'-UTR may contribute to the etiology or modulate the risk of T2DM, whereas the rs689466 variant of the COX2 gene is not associated with T2DM risk.

POLYMORPHISM OF THE COX-2 GENE AND SUSCEPTIBILITY TO COLON AND RECTAL CANCER

Background:

The colorectal neoplasm is the fourth most common malignancy among males and the third among females. In the Western world is estimated that 5% of the population will develop it, making this disease a major public health problem.

Aim:

To analyze the prevalence of the polymorphism -765G / C region of the COX-2 gene in colorectal cancer patients compared to a control group, analyzing the possible association between this polymorphism and susceptibility to colorectal cancer.

Method:

This is a case-control study with 85 participants. Were selected 25 with colorectal cancer (case group) and 60 participants without colorectal neoplasia (control group). The molecular genetic analysis was perform to identify the polymorphism -765G / C COX2 gene with standard literature technique. In addition, patient’s clinical and pathological data were analyzed.

Results:

There was a light increase in prevalence between men in the case group, although this difference was not statistically significant. The results showed a high prevalence of GC and CC genotype in individuals with colorectal cancer, demonstrating an association between the presence of the polymorphism in the COX2 gene and susceptibility to colorectal cancer in this pattern (p=0.02). Similarly, there was also difference in allele frequencies in the groups. When patients with cancer were separated by tumor location, there was a higher prevalence of polymorphism in the left colon (p=0.02).

Conclusion:

The polymorphism in the COX2 gene is associated with increased susceptibility to colorectal cancer, specially rectosigmoid tumors.

COX-2 rs5275 and rs689466 polymorphism and risk of lung cancer: A PRISMA-compliant meta-analysis

BACKGROUND

Cyclooxygenase-2 (COX-2) is an inducible enzyme that mediates the synthesis of prostaglandin, which plays an important role in the inflammation response. The overexpression of COX-2 in lung cancer has been found in several studies, suggesting that COX-2 contributes to carcinogenesis. There are many previous case-control studies focused on the association between COX-2 polymorphism and lung cancer risk, however, the conclusion remained controversial.

OBJECTIVES

We performed this meta-analysis to evaluate the association between COX-2 rs5275 and rs689466 polymorphism and susceptibility to lung cancer.

METHODS

A systematic literature research was conducted on PubMed, Embase, Cochrane Library, OVID, Web of Science, and Google Scholar up to November 30, 2017. The quality of studies was assessed by Newcastle-Ottawa scale. We combined odds ratios (ORs) and 95% confidence intervals (CIs) in 5 different genetic models for evaluation under a fixed-effect model or random-effect model. Subgroup analysis was performed according to source of control, ethnicity, pathological types, and smoking status. Sensitivity analysis and publication bias were also conducted.

RESULTS

Eventually, 14 eligible studies were included in our meta-analysis. We found rs5275 gene polymorphism decreased the risk of lung cancer under heterozygote model (OR: 0.91, 95% CI: 0.84-0.98, P = .02). COX-2 rs689466 gene polymorphism was also related to a significantly reduced risk under allele (OR: 0.88, 95% CI: 0.82-0.95, P = .001), homozygote (OR: 0.81, 95% CI: 0.68-0.95, P = .01), heterozygote (OR: 0.81, 95% CI: 0.72-0.91, P < .001), and dominant model (OR: 0.81, 95% CI: 0.72-0.91, P < .001), except for recessive model. Subgroup analysis suggested a similar association in Asians, but not in Caucasians. Polymorphism of rs5275 was strongly associated with a reduced risk of lung adenocarcinoma according to stratified analysis by pathological types. Egger test identified no significant publication bias.

CONCLUSIONS

Our meta-analysis demonstrated that COX-2 rs5275 and rs689466 polymorphism significantly decrease the risk of lung cancer in Asians but not in Caucasians, indicating COX-2 could serve as a potential diagnostic marker for lung cancer.

Functional analysis of polymorphisms in the COX-2 gene and risk of lung cancer

The enzyme cyclooxygenase 2 (COX-2) is known to be involved in tumorigenesis and metastasis in certain types of cancer. Nevertheless, the prognostic value of COX-2 overexpression and its polymorphisms in patients with non-small cell lung cancer (NSCLC) have yet to be fully elucidated. The aim of the present study was to investigate the association between the three most commonly studied COX-2 gene polymorphisms (-1195 G/A, -765 G/C and 8473 T/C) with COX-2 expression and lung cancer risk in a Brazilian cohort. In the present hospital based, case-control retrospective study, 104 patients with NSCLC and 202 cancer free control subjects were genotyped for -1195 G/A, -765 G/C and 8473 T/C polymorphisms using allelic discrimination with a reverse transcription quantitative polymerase chain reaction method. COX-2 mRNA expression was analyzed in surgically resected tumors from 34 patients with NSCLC. The results revealed that COX-2 expression levels were higher in tumor tissue compared with normal lung tissue. However, this overexpression of COX-2 was not associated with the patient outcome, and furthermore, none of the analyzed polymorphisms were associated with the risk of developing lung cancer, COX-2 overexpression, or the overall survival of the patients with NSCLC. Taken together, the findings described in the present study do not support a major role for COX-2 polymorphisms and COX-2 overexpression in lung carcinogenesis within the Brazilian population.

Association Between COX-2 Polymorphisms and Lung Cancer Risk

BACKGROUND Multiple relevant risk factors for lung cancer have been reported in different populations, but results of previous studies were not consistent. Therefore, a meta-analysis is necessary to summarize these outcomes and reach a relatively comprehensive conclusion. MATERIAL AND METHODS STATA 12.0 software was used for all statistical of the relationship between COX-2 polymorphisms and lung cancer risk. Inter-study heterogeneity was examined with the Q statistic (significance level at P<0.1). The publication bias among studies in the meta-analysis was analyzed with Begg's funnel plot and Egger's test. Hardy-Weinberg equilibrium was tested in all controls of the studies. RESULTS COX-2 rs20417 polymorphism had a significant association with reduced risk of lung cancer under homozygous and recessive models, and similar results were observed in white and population-based subgroups under 2 and 3 contrasts, respectively. Additionally, rs2066826 polymorphism manifested a strong correlation with increased risk of lung cancer under 5 genetic models. CONCLUSIONS In COX-2 gene, rs20417 may have a certain relationship with reduced risk of lung cancer, while rs2066826 may increase the risk of lung cancer.

The VEGFR2, COX-2 and MMP-2 polymorphisms are associated with clinical outcome of patients with inoperable non-small cell lung cancer

Certain common inherited variations in genes involved in tumor angiogenesis, progression and metastasis may contribute to cancer therapy outcome and prognosis by altering the gene expression and protein activity. In this report, we examined the effect of functional polymorphisms in MMP-1, MMP-2, MMP-3, VEGF, VEGFR2, FGFR4 and COX-2 genes on overall (OS) and progression-free survival (PFS) of 350 Caucasian patients with inoperable non-small cell lung cancer (NSCLC). The results of multivariate analysis indicated that VEGFR2 -906C and COX-2 -1195G alleles were strongly associated with poor OS and PFS (p = 0.002 and 0.015, respectively, for OS; p = 0.009 and 0.015, respectively, for PFS), while MMP-2 -1306 T allele carriers had significantly reduced PFS (p = 0.010). Moreover, an increased risk of death and progression was significantly associated with the number of adverse alleles for VEGFR2/COX-2 (p = 0.0005 for OS and 0.0006 for PFS in >1 adverse allele carriers) and VEGFR2/COX-2/MMP-2 combinations (p = 0.0003 for OS and 0.0001 for PFS in patients with >2 adverse alleles). Finally, VEGFR2 TC/CC, COX-2 AG/GG and MMP-2 CT/TT genotypes as well as "at risk" allele combinations were identified as independent predictors of unfavorable OS and PFS in the group. In conclusion, the data suggest that selected VEGFR2, COX-2 and MMP-2 polymorphisms may be potential prognostic markers in unresectable NSCLC treated with radiotherapy with or without chemotherapy, although further validation studies are warranted to confirm our observations.

Meta-analysis of the association between COX-2 polymorphisms and risk of colorectal cancer based on case-control studies

OBJECTIVE

Cyclooxygenase-2 (COX-2) is an inducible enzyme converting arachidonic acid to prostaglandins and playing important roles in inflammatory diseases as well as tumor development. Previous studies investigating the association between COX-2 polymorphisms and colorectal cancer (CRC) risk reported conflicting results. We performed a meta-analysis of all available studies to explore this association.

METHODS

All studies published up to October 2013 on the association between COX-2 polymorphisms and CRC risk were identified by searching electronic databases PubMed, EMBASE, and Cochrane library. The association between COX-2 polymorphisms and CRC risk was assessed by odds ratios (ORs) together with their 95% confidence intervals (CIs).

RESULTS

Ten studies with 6,774 cases and 9,772 controls were included for -1195A>G polymorphism, 13 studies including 6,807 cases and 10,052 controls were available for -765G>C polymorphism, and 8 studies containing 5,121 cases and 7,487 controls were included for 8473T>C polymorphism. With respect to -765G>C polymorphism, we did not find a significant association with CRC risk when all eligible studies were pooled into the meta-analysis. However, in subgroup analyses by ethnicity and cancer location, with a Bonferroni corrected alpha of 0.05/2, statistical significant increased CRC risk was found in the Asian populations (dominant model CC+CG vs. GG: OR = 1.399, 95%CI: 1.113-1.760, P = 0.004) and rectum cancer patients (CC vs. GG: OR = 2.270, 95%CI: 1.295-3.980, P = 0.004; Recessive model CC vs. CG+GG: OR = 2.269, 95%CI: 1.297-3.970, P = 0.004). In subgroup analysis according to source of control, no significant association was detected. With respect to -1195A>G and 8473T>C polymorphisms, no significant association with CRC risk was demonstrated in the overall and subgroup analyses.

CONCLUSIONS

The present meta-analysis suggests that the COX-2 -765G>C polymorphism may be a risk factor for CRC in Asians and rectum cancer patients. Further large and well-designed studies are needed to confirm this association.

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.

The association between COX-2 polymorphisms and hematologic toxicity in patients with advanced non-small-cell lung cancer treated with platinum-based chemotherapy

Background and Objective

Overexpression of COX-2 is proved to contribute to tumor promotion and carcinogenesis through stimulating cell proliferation, inhibiting apoptosis and enhancing the invasiveness of cancer cells. Apoptosis-related molecules are potential predictive markers for survival and toxicity in platinum treatment. This study aimed at investigating the association between COX-2 polymorphisms and the occurrence of grade 3 or 4 toxicity in advanced non–small cell lung cancer patients treated with platinum-based chemotherapy.

Materials and Methods

Two hundred and twelve patients with inoperable stage IIIB-IV NSCLC received first-line chemotherapy between 2007 and 2009 were recruited in this study. Four functional COX-2 polymorphisms were genotyped by PCR-based restriction fragment length polymorphism (RFLP) methods.

Results

The incidence of grade 3 or 4 hematologic toxicity was significantly higher in G allele carriers of the COX-2 rs689466 (−1195G/A) polymorphism compared with wild-type homozygotes AA (P value = 0.008; odds ratio, 2.47; 95% confidence internal, 1.26–4.84) and the significance still existed after the Bonferroni correction. Statistically significant difference was also found in grade 3 or 4 leukopenia (P value = 0.010; OR = 2.82; 95%CI = 1.28–6.20). No other significant association was observed between genotype and toxicity in the study. The haplotype analysis showed that the haplotype AGG was associated with a reduced risk of grade 3 or 4 hematologic and leukopenia toxicity (P value = 0.009; OR = 0.59; 95%CI = 0.39–0.88 and P value = 0.025; OR = 0.61; 95%CI = 0.39–0.94, respectively) while the haplotype GGG was associated with an increased risk of grade 3 or 4 hematologic and leukopenia toxicity (P value = 0.009; OR = 1.71; 95%CI = 1.14–2.56 and P value = 0.025; OR = 1.65; 95%CI  = 1.06–2.57, respectively).

Conclusion

This investigation for the first time suggested that polymorphism in COX-2 rs689466 may be a potent bio-marker in predicting severe hematologic toxicity in NSCLC patients after platinum-based chemotherapy.

Role of cyclooxygenase-2 gene polymorphisms in pancreatic carcinogenesis

AIM: To evaluate the clinical significance of -765G/C and -1195G/A cyclooxygenase-2 (COX-2) gene polymorphisms in patients with pancreatic cancer (PC).

METHODS: The study included 201 patients: 85 with PC and 116 healthy controls. -765G/C and -1195G/A COX-2 gene polymorphisms were studied in DNA isolated from blood samples. The associations of the analyzed genotypes and clinical data at diagnosis were evaluated.

RESULTS: We found an increased frequency of the homozygous -1195AA COX-2 genotype in patients with PC (53.7%) compared with the control group (21%) (P < 0.01). In contrast, the distribution of genotype and allele frequencies of the -765G/C COX-2 polymorphism in the PC patients were not different from those in control groups. A correlation between presence of homozygous -1195AA COX-2 genotype and tumor size > 3 cm was observed (P < 0.05). Analyzed polymorphisms were unrelated to the patients’ sex and age, nor to the presence of regional or distant metastases.

CONCLUSION: These preliminary results indicate that the -1195G/A COX-2 polymorphism may play an important role in PC prognosis and carcinogenesis.

Cyclooxygenase-2 polymorphisms and the risk of gastric cancer in various degrees of relationship in the Chinese Han population

A number of studies have shown that cyclooxygenase-2 (COX-2) gene polymorphisms were associated with gastric cancer. However, the results from different research groups have not been consistent. The present study aimed to investigate the association between polymorphisms of the cyclooxygenase-2 promoter region (-1195G>A, -765G>C) and gastric cancer patients with various degrees of relationship in the Chinese Han population. COX-2-1195G>A and COX-2-765G>C polymorphisms in 296 gastric cancer patients and 319 control family members were genotyped using polymerase chain reaction-restriction fragment length polymorphism. An increased risk of gastric cancer was observed in subjects with the COX-2-1195AA genotype (OR=2.03; 95% CI, 1.27-3.22), and the association strength decreased as the degree of relationship decreased. Stratification analysis revealed that the OR value of COX-2-1195AA genotype and A carriers exhibited synergy with Helicobacter pylori (H. pylori) infection (AA genotype: OR=2.96; 95% CI, 1.57-5.58; A carriers: OR=2.04; 95% CI, 1.18-3.52). No significant difference was found in each genotype of COX-2-765G>C between gastric cancer patients and control family members, as well as gastric cancer patients with various degrees of relationship. Our study demonstrated that the polymorphism of COX-2-1195AA genotype may be a risk factor for gastric cancer patients with various degrees of relationship among the Chinese Han population. H. pylori infection therefore may enhance the risk of gastric cancer in individuals with the COX-2-1195 AA genotype.

Functional polymorphism of cyclooxygenase-2 gene (G-765C) in chronic obstructive pulmonary disease patients

Cyclooxygenase two (COX-2) is an important enzyme metabolizing arachidonic acid. In contrast to constitutive cyclooxygenase one (COX-1), COX-2 is induced by proinflammatory factors. Polymorphism -765 G/C in COX-2-encoding gene promoter is associated with development of Alzheimer's disease, depression, carcinoma of the pancreas in smokers, breast cancer and rheumatoid arthritis. It is interesting whether the -765 G/C polymorphism in COX-2-encoding gene promoter can be associated with COPD, a disease which is inflammatory in character. It is highly probable as the breast and pancreas cancers, whose associations with the analyzed polymorphism have been studied, are smoking-dependent tumors. Additionally, tobacco smoke has been demonstrated to induce COX-2 in the lungs. The study group consisted of 122 COPD patients (48 females, 74 males). The control group consisted of 149 healthy nonsmoking subjects (83 females, 66 males). Polymerase chain reaction/restriction fragment length polymorphism was used for genotyping. A statistically significant difference in genotype distribution was observed as a result of the comparison between healthy subjects and patients with COPD. The distribution of alleles in both groups conformed with Hardy-Weinberg equilibrium. In the group of COPD patients, GG allele was found in 79 subjects, GC in 36, and CC in 7 subjects (F = 0.094, P = 0.296927); in the control group, 73 subjects had GG allele, 68--GC and 8--CC (F = 0.12728, P = 0.120265). The allele frequency revealed differences between those groups, attaining the level of statistical significance (χ(2) = 29.043, df = 2, P = 0.0000. The carriers of -765 G allele are at 1.53-fold higher risk of developing COPD. The presence of GG genotype does not increase significantly the risk of the disease. It is also noteworthy that the carriers of CC or GC genotypes are at significantly lower risk of developing COPD than the group of subjects with GG genotype.