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

Hypoxia, NSAIDs, and autism: A biocultural analysis of stressors in gametogenesis

Cultural and generational trends have increasingly favored "anti-inflammatory" action, innovating a new class of analgesic, non-steroidal anti-inflammatory drugs (NSAIDs) in the 20th century. The modern human body has been molded over evolutionary time and while acknowledging inflammation can be pathologically entwined, it also serves an important role in healthy folliculogenesis and ovulation, shaping cues that drive needed vascular change. This review argues that because of anti-inflammatory action, the cultural invention of NSAIDs represents a particular stressor on female reproductive-age bodies, interacting with natural, underlying variation and placing limits on healthy growth and development in the follicles, creating potential autism risk through hypoxia and mutagenic or epigenetic effects. Since testes are analogs to ovaries, the biological grounding extends naturally to spermatogenesis. This review suggests the introduction of over-the-counter NSAIDs in the 1980s failed to recognize the unique functioning of reproductive-age bodies, challenging the cyclical inflammation needed for healthy gamete development. NSAIDs are framed as one (notable) stressor in an anti-inflammatory era focused on taming the risks of inflammation in modern human life.

Connection of COX-2 variants to ankylosing spondylitis susceptibility

This study aimed to explore the associations of COX-2 polymorphisms rs5275, rs20417, and rs2745557 with the susceptibility to ankylosing spondylitis among Chinese Han people. Polymerase chain reaction-restriction fragment length polymorphism (PCR/RFLP) was adopted for genotyping COX-2 polymorphisms rs5275, rs20417, and rs2745557 among 109 AS patients and 122 healthy controls. Genotype distribution in the control group was examined for these three polymorphisms to test whether it conformed to Hardy-Weinberg equilibrium (HWE) expectation. A χ2 -test was employed to compare genotype and allele frequencies between the two groups. Besides this, logistic regression analyses were also performed to adjust age and gender. A p less than .05 represented a significant level. Genotype distribution of our studied polymorphisms showed fine conformity to HWE in the controls. An increasing effect on AS risk was detected for the polymorphism rs5275 under GG versus AA contrast (crude: OR, 3.040; 95% CI, 1.015-9.104), and the adjustment for age and gender did not change such a relationship (adjusted OR, 3.307; 95% CI, 1.065-10.268). After adjusting age and gender, both polymorphisms of rs20417 and rs2745557 demonstrated a negative relationship with the disease susceptibility. The GC genotype and C allele of rs20417 reduced the disease risk to 0.248 (adjusted: 95% CI, 0.089-0.692) and 0.269 (95% CI, 0.098-0.733), respectively, while the AA genotype and A allele of the latter to 0.413 (adjusted: 95% CI, 0.191-0.893) and 0.676 (adjusted: 95% CI, 0.466-0.981), respectively. Among Chinese Han people, COX-2 polymorphism rs5275 may contribute to increased risk of developing AS, while the polymorphisms rs20417 and rs2745557 may offer protection against disease incidence.

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.

Strain-specific behavior of Mycobacterium tuberculosis in A549 lung cancer cell line

BACKGROUND

A growing body of evidence has shown the association between tuberculosis (TB) infection and lung cancer. However, the possible effect of strain-specific behavior of Mycobacterium tuberculosis (M.tb) population, the etiological agent of TB infection in this association has been neglected. In this context, this study was conducted to investigate this association with consideration of the genetic background of strains in the M.tb population.

RESULTS

We employed the elastic net penalized logistic regression model, as a statistical-learning algorithm for gene selection, to evaluate this association in 129 genes involved in TLRs and NF-κB signaling pathways in response to two different M.tb sub-lineage strains (L3-CAS1and L 4.5). Of the 129 genes, 21 were found to be associated with the two studied M.tb sub-lineages. In addition, MAPK8IP3 gene was identified as a novel gene, which has not been reported in previous lung cancer studies and may have the potential to be recognized as a novel biomarker in lung cancer investigation.

CONCLUSIONS

This preliminary study provides new insights into the mechanistic association between TB infection and lung cancer. Further mechanistic investigations of this association with a large number of M.tb strains, encompassing the other main M.tb lineages and using the whole transcriptome of the host cell are inevitable.

Roles of Cyclooxygenase-2 gene -765G > C (rs20417) and -1195G > A (rs689466) polymorphisms in gastric cancer: A systematic review and meta-analysis

BACKGROUND

The roles of cyclooxygenase-2 (COX2) -765G > C (rs20417) and -1195G > A (rs689466) polymorphisms in gastric cancer were intensively analyzed, but the results of these studies were inconsistent. We conducted a meta-analysis and trial sequential analysis to elucidate the associations between these two COX2 polymorphisms and gastric cancer risk.

METHODS

Eligible studies were searched in PubMed, Embase, Cochrane library databases, China National Knowledge Infrastructure, Vip, and Wanfang databases. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the genetic correlation between COX2 polymorphisms and gastric cancer susceptibility in five genetic models. Trial sequential analysis (TSA) was conducted to estimate whether the evidence of the results is sufficient. Furthermore, their interactions with Helicobacter pylori (H. pylori) or smoking in gastric cancer were also assessed using a case-only method.

RESULTS

The COX2 gene -765G > C polymorphism showed no significant association with gastric cancer susceptibility under all the five genetic models (take the allelic model for example: OR = 1.41, 95% CI: 0.95-2.09) in total analysis, and the stratification analysis by ethnicity indicated a similar association in Caucasian group under four genetic models (allelic model, dominant model, homozygous model, and heterozygous model). But in the subgroup of the Asian population, the -765G > C polymorphism was significantly associated with gastric cancer risk under the same contrast. The COX2 -1195G > A polymorphism showed significant correlation with gastric cancer susceptibility in total analysis, and stratification analysis by ethnicity also revealed a similar association in both Asian and Caucasian groups under the same contrast. Moreover, TSA confirmed such associations. Both H. pylori infection and cigarette smoking interacted with -765 C allele in gastric cancer (OR = 3.79, 95% CI: 1.15-12.43 and OR = 2.48, 95% CI: 1.38-4.48, respectively), but not in -1195 A allele (OR = 1.96, 95% CI: 0.62-6.21, and OR = 1.24, 95% CI: 0.93-1.64, respectively).

CONCLUSIONS

COX2 -765G > C polymorphism may serve as a genetic biomarker of gastric cancer in Asians, but not in Caucasians. COX2 -1195G > A polymorphism may serve as a genetic biomarker of gastric cancer in both Asians and Caucasians. The -765G > C, rather than -1195G > A polymorphism interacted with H. pylori infection or cigarette smoking to increase gastric cancer risk.

Association between cyclooxygenase-2 (COX-2) 8473 T > C polymorphism and cancer risk: a meta-analysis and trial sequential analysis

Background

Numerous studies have investigated the relationship between COX-2 8473 T > C polymorphism and cancer susceptibility, however, the results remain controversial. Therefore, we carried out the present meta-analysis to obtain a more accurate assessment of this potential association.

Methods

In this meta-analysis, 79 case-control studies were included with a total of 38,634 cases and 55,206 controls. We searched all relevant articles published in PubMed, EMBASE, OVID, Web of Science, CNKI and Wanfang Data, till September 29, 2017. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the strength of the association. We performed subgroup analysis according to ethnicity, source of controls, genotyping method and cancer type. Moreover, Trial sequential analysis (TSA) was implemented to decrease the risk of type I error and estimate whether the current evidence of the results was sufficient and conclusive.

Results

Overall, our results indicated that 8473 T > C polymorphism was not associated with cancer susceptibility. However, stratified analysis showed that the polymorphism was associated with a statistically significant decreased risk for nasopharyngeal cancer and bladder cancer, but an increased risk for esophageal cancer and skin cancer. Interestingly, TSA demonstrated that the evidence of the result was sufficient in this study.

Conclusion

No significant association between COX-2 8473 T > C polymorphism and cancer risk was detected.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4753-3) contains supplementary material, which is available to authorized users.

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.

Differential exposure and acute health impacts of inhaled solid-fuel emissions from rudimentary and advanced cookstoves in female CD-1 mice

BACKGROUND

There is an urgent need to provide access to cleaner end user energy technologies for the nearly 40% of the world's population who currently depend on rudimentary cooking and heating systems. Advanced cookstoves (CS) are designed to cut emissions and solid-fuel consumption, thus reducing adverse human health and environmental impacts.

STUDY PREMISE

We hypothesized that, compared to a traditional (Tier 0) three-stone (3-S) fire, acute inhalation of solid-fuel emissions from advanced natural-draft (ND; Tier 2) or forced-draft (FD; Tier 3) stoves would reduce exposure biomarkers and lessen pulmonary and innate immune system health effects in exposed mice.

RESULTS

Across two simulated cooking cycles (duration ~ 3h), emitted particulate mass concentrations were reduced 80% and 62% by FD and ND stoves, respectively, compared to the 3-S fire; with corresponding decreases in particles visible within murine alveolar macrophages. Emitted carbon monoxide was reduced ~ 90% and ~ 60%, respectively. Only 3-S-fire-exposed mice had increased carboxyhemoglobin levels. Emitted volatile organic compounds were FD ≪ 3-S-fire ≤ ND stove; increased expression of genes involved in xenobiotic metabolism (COX-2, NQO1, CYP1a1) was detected only in ND- and 3-S-fire-exposed mice. Diminished macrophage phagocytosis was observed in the ND group. Lung glutathione was significantly depleted across all CS groups, however the FD group had the most severe, ongoing oxidative stress.

CONCLUSIONS

These results are consistent with reports associating exposure to solid fuel stove emissions with modulation of the innate immune system and increased susceptibility to infection. Lower respiratory infections continue to be a leading cause of death in low-income economies. Notably, 3-S-fire-exposed mice were the only group to develop acute lung injury, possibly because they inhaled the highest concentrations of hazardous air toxicants (e.g., 1,3-butadiene, toluene, benzene, acrolein) in association with the greatest number of particles, and particles with the highest % organic carbon. However, no Tier 0-3 ranked CS group was without some untoward health effect indicating that access to still cleaner, ideally renewable, energy technologies for cooking and heating is warranted.