Cyclooxygenase-2 169C>G and 8473T>C gene polymorphisms and prostaglandin E2 level in breast cancer: a case-control study

Prostaglandin Endoperoxide H Synthase-2 (PGHS-2) Variants and Risk of Obesity and Microvascular Dysfunction Among Tunisians: Relevance of rs5277 (306G/C) and rs5275 (8473T/C) Genetic Markers

The purpose of this study was to determine the impact of six PGHS-2 genetic variants on obesity development and microvascular dysfunction. The study included 305 Tunisian subjects (186 normal weights, 35 overweights and 84 obeses). PCR analyses were used for allelic discrimination between polymorphisms. Prostaglandin (PGE2, PGI2), leptin, and matrix metalloproteinase (MMP1, 2, 3, 9) levels were evaluated by ELISA. Fatty acid composition was performed by gas chromatography-mass spectrometry. Our results revealed that subjects carrying the PGHS-2 306CC (rs5277) and 8473CC (rs5275) genotypes present higher anthropometric values compared to wild-type genotypes (306GG, BMI (Kg/m²): 27.11 ± 0.58; WC (cm): 93.09 ± 1.58; 306CC, BMI: 33.83 ± 2.46; WC: 109.93 ± 5.41; 8473TT, BMI: 27.75 ± 0.68; WC: 93.96 ± 1.75; 8473CC, BMI: 33.72 ± 2.2; WC: 117.89 ± 2.94). A reduced microvascular reactivity and a higher PGE2 level were also found in individuals with the 306CC and 8473CC genotypes in comparison to 306GG and 8473TT carriers (306GG, Peak Ach-CVC (PU/mmHg): 0.46 ± 0.03; PGE2 (pg/ml): 7933.1 ± 702; 306CC, Peak Ach-CVC: 0.24 ± 0.01; PGE2: 13,380.3 ± 966.2; 8473TT, Peak Ach-CVC: 0.48 ± 0.05; PGE2: 7086.41 ± 700.31; 8473CC, Peak Ach-CVC: 0.23 ± 0.01; PGE2: 13,175.7 ± 1165.8). Fatty acid analysis showed a significant increase of palmitic acid (PA) (34.2 ± 2.09 vs. 16.82% ± 1.76, P < 0.001), stearic acid (SA) (25.76 ± 3.29 vs. 9.05% ± 2.53, P < 0.001), and linoleic acid (LA) (5.25 ± 1.18 vs. 0.5% ± 0.09, P < 0.001) levels in individuals carrying the PGHS-2 306CC genotype when compared to GG genotype individuals. Subjects with the 8473CC genotype showed also a significant increase of PA, SA ,and LA levels when compared to TT genotype carriers (PA: 38.02 ± 1.51 vs. 12.65% ± 1.54, P < 0.001; SA: 32.96 ± 1.87 vs. 1.38% ± 0.56, P < 0.001; LA: 26.84 ± 2.09 vs. 3.7% ± 1.54, P < 0.001). Logistic regression analysis revealed that PGHS-2 306CC and 8473CC variants are significantly associated with obesity status (OR 6.25, CI (1.8-21.6), P = 0.004; OR 3.01, CI (1.13-8.52), P = 0.03, respectively). Haplotypes containing the C₃₀₆:T₈₄₇₃ (OR 2.91; P = 0.01) and G_306:C₈₄₇₃ (OR 5.25; P = 0.002) combinations were associated with an enhanced risk for obesity development in the studied population. In conclusion, our results highlight that PGHS-2 306G/C and 8473T/C variants could be useful indicators of obesity development, inflammation, and microvascular dysfunction among Tunisians.

A Review of Cancer Genetics and Genomics Studies in Africa

Cancer is the second leading cause of death globally and is projected to overtake infectious disease as the leading cause of mortality in Africa within the next two decades. Cancer is a group of genomic diseases that presents with intra- and inter-population unique phenotypes, with Black populations having the burden of morbidity and mortality for most types. At large, the prevention and treatment of cancers have been propelled by the understanding of the genetic make-up of the disease of mostly non-African populations. By the same token, there is a wide knowledge gap in understanding the underlying genetic causes of, and genomic alterations associated with, cancer among black Africans. Accordingly, we performed a review of the literature to survey existing studies on cancer genetics/genomics and curated findings pertaining to publications across multiple cancer types conducted on African populations. We used PubMed MeSH terms to retrieve the relevant publications from 1990 to December 2019. The metadata of these publications were extracted using R text mining packages: RISmed and Pubmed.mineR. The data showed that only 0.329% of cancer publications globally were on Africa, and only 0.016% were on cancer genetics/genomics from Africa. Although the most prevalent cancers in Africa are cancers of the breast, cervix, uterus, and prostate, publications representing breast, colorectal, liver, and blood cancers were the most frequent in our review. The most frequently reported cancer genes were BRCA1, BRCA2, and TP53. Next, the genes reported in the reviewed publications’ abstracts were extracted and annotated into three gene ontology classes. Genes in the cellular component class were mostly associated with cell part and organelle part, while those in biological process and molecular function classes were mainly associated with cell process, biological regulation, and binding, and catalytic activity, respectively. Overall, this review highlights the paucity of research on cancer genomics on African populations, identified gaps, and discussed the need for concerted efforts to encourage more research on cancer genomics in Africa.

Association of the cyclooxygenase-2 1759A allele with migraine in Chinese Han individuals

Cyclooxygenase-2 (COX-2) is known to be involved in the pathogenesis of migraine, and some polymorphisms are known to affect the expression of COX-2. This retrospective case-control study aimed to explore the associations between the -765 G>C (rs20417), -1759 G>A (rs3218625), and -8473 C>T (rs5275) COX-2 polymorphisms and migraine in Chinese Han individuals. One hundred and ten unrelated Han Chinese patients with migraine and 108 healthy controls were recruited between 03/2014 and 08/2016 at the First Affiliated Hospital of Nanjing Medical University and the First People's Hospital of Lianyungang City. The genotypes of all polymorphisms in controls followed the Hardy-Weinberg equilibrium (P = 0.215, P = 0.884, and P = 0.689). There were differences in the genotype and allele distributions of the COX-2-1759G>A (Gly587Arg) polymorphism between the migraine and control groups (P = 0.038 and P = 0.040, respectively). Compared with the COX-2-1759AG genotype, GG genotype carriers had an increased risk of migraine (odds ratio (OR) = 8.720, 95% confidence interval (CI): 1.072-70.960, P = 0.038). The frequency of the COX-2-1759A allele in patients with migraine was significantly lower than the controls (OR = 0.119, 95%CI: 0.015-0.957, P = 0.040). Adjusted age and sex, a statistical difference was found in the dominant model of COX-2-1759 G>A (OR = 0.118, 95% CI 0.014 to 0.962, P = 0.046). No significant difference was detected regarding the -765G>C and -8473T>C polymorphisms between the two groups. The COX-2 1759A allele might be involved in the development of migraine in Chinese Han individuals, but this will have to be confirmed in large-scale studies.

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.

Cyclooxygenase-2 (COX-2) gene polymorphism in patients with differentiated thyroid carcinomas in the Turkish population

Background/aim: The most common thyroid malignancies are papillary and follicular thyroid carcinomas. They account for approximately 85%-90% of all thyroid cancers. Recent studies have reported the relevance of cyclooxygenase-2 (COX-2) gene polymorphism in human carcinogenesis. The aim of this study was to investigate the relationship between thyroid carcinoma and COX-2 gene polymorphism in the Turkish population.Materials and methods: We included a total of 96 differentiated thyroid cancer patients (mean age: 46.9 ± 10.3 years; 14 males, 82 females) and 83 healthy control subjects (mean age: 46.0 ± 10.6 years; 39 males, 44 females). The frequency of -765G>C, -8473T>C, and 1195A>G gene polymorphisms in the COX-2 promoter region was investigated in thyroid cancer patients and the control group using the high-resolution melting method. Results: COX-2-765G>C and COX-2-1195A>G gene polymorphisms were similar between thyroid cancer patients and the control group. There was a statistically significant difference between COX-2-8473T>C gene polymorphism in the thyroid cancer group and the control group (P = 0.012).Conclusion: The single nucleotide gene polymorphism COX-2-8473T>C might contribute to genetic susceptibility to differentiated thyroid cancer in the Turkish population.

The effects of EPA and DHA enriched fish oil on nutritional and immunological markers of treatment naïve breast cancer patients: a randomized double-blind controlled trial

BACKGROUND

We evaluated the effects of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids enriched fish oil (FO) on nutritional and immunological parameters of treatment naïve breast cancer patients.

METHODS

In a randomized double blind controlled trial, the FO group (FG) patients were supplemented with 2 g/ day of FO concentrate containing 1.8 g of n-3 fatty acids during 30 days. The placebo group (PG) received 2 g/ day of mineral oil. At baseline and after the intervention, plasma levels of n-3 fatty acids, dietary intake, weight, body composition, biochemical and immunological markers were assessed.

RESULTS

At the end of the intervention period, no between group differences were observed regarding anthropometric parameters. There was a significant increase in the plasma phospholipid EPA (p = 0.004), DHA (p = 0.007) of the FG patients. In FG patients the percentages of peripheral blood CD4+ T lymphocytes and serum high sensitivity C-reactive protein (hsCRP) levels were maintained while in PG patients there was a significant increase in hsCRP (p = 0.024). We also observed a significant reduction in the percentage of CD4+ T lymphocytes in the peripheral blood (p = 0.042) of PG patients. No changes in serum proinflammatory cytokine and prostaglandin E2 levels were observed.

CONCLUSIONS

Supplementation of newly diagnosed breast cancer patients with EPA and DHA led to a significant change in the composition of plasma fatty acids, maintained the level of CD4+ T cells and serum levels of hsCRP, suggestive of a beneficial effect on the immune system and less active inflammatory response.

TRIAL REGISTRATION

Brazilian Clinical Trials Registry (REBEC): RBR-2b2hqh. Registered 29 April 2013, retrospectively registered.

Potential biomarker panels in overall breast cancer management: advancements by multilevel diagnostics

Breast cancer (BC) prevalence has reached an epidemic scale with half a million deaths annually. Current deficits in BC management include predictive and preventive approaches, optimized screening programs, individualized patient profiling, highly sensitive detection technologies for more precise diagnostics and therapy monitoring, individualized prediction and effective treatment of BC metastatic disease. To advance BC management, paradigm shift from delayed to predictive, preventive and personalized medical services is essential. Corresponding step forwards requires innovative multilevel diagnostics procuring specific panels of validated biomarkers. Here, we discuss current instrumental advancements including genomics, proteomics, epigenetics, miRNA, metabolomics, circulating tumor cells and cancer stem cells with a focus on biomarker discovery and multilevel diagnostic panels. A list of the recommended biomarker candidates is provided.

Breast Cancer Genetic and Molecular Subtype Impacts Response to Omega-3 Fatty Acid Ethyl Esters

Epidemiological studies have correlated frequent omega-3 (n-3) fatty acid consumption with a lower risk for breast cancer; however, recent prospective studies have been less conclusive. Efforts in the preventive setting have focused on the use of n-3 fatty acids, and the pharmaceutical ethyl esters (EE) of these natural compounds, for high-risk patient populations. Limited understanding of specific mechanisms by which these agents function has hampered identification of the cancer subtype(s) that would gain the greatest therapeutic benefit. In this study, we investigated the in vitro effects of n-3 EEs in four distinct breast cancer subtypes and explored how they affect not only breast cancer cell survival but also modulate the nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB) and peroxisome proliferator-activated receptor gamma signaling pathways. Similar to the high variance in response observed in human studies, we found that the effectiveness of n-3 EEs depends on the molecular characteristics of the MCF-7, CAMA-1, MDA-MB-231, and SKBR3 breast cancer cell lines and is closely associated with the suppression of NF-κB. These data strongly suggest that the use of n-3 fatty acids and their pharmaceutical ether esters in the prevention and therapeutic setting should be guided by specific tumor characteristics.

Five COX-2 gene polymorphisms and risk of breast cancer: an updated meta-analysis based on 19 case-control studies

The correlationship between COX-2 gene polymorphisms and breast cancer has been wildly studied, but the results remain controversial. Hence, the present meta-analysis aimed to investigate the association between COX-2 SNPs (rs5275, rs20417, rs689466, rs5277, rs2206593) and risk of breast cancer. Data were collected from PubMed, Embase and China National Knowledge Infrastructure. Summary odds ratio (OR) with 95 % confidence interval (CI) was applied to assess the relationship. Heterogeneity test, sensitivity analysis and publication bias test were also performed. There were 17 articles that contained 19 studies in this research. Fourteen case-control studies with 15,007 breast cancer cases and 20,005 controls were concerning rs5275 polymorphism, and 8 case-control studies with 10,216 cases and 12,839 controls were about rs20417 polymorphism. Other three polymorphisms (rs689466, rs2206593, rs5277) were studied in 5, 3 and 3 studies, respectively. COX-2-rs20417 CC genotype was significantly associated with increased risk of breast cancer when comparing to G allele [ORs were 1.231 (1.050-1.444) for CC vs. GG, P = 0.01, 1.223 (1.045-1.432) for CC vs. G carrier, P = 0.01]. Furthermore, the results of the subgroup analysis by ethnicity suggested that C allele significantly contributed to the risk of breast cancer for Asians [1.459 (1.182-1.802) for GC vs. GG, 1.472 (1.201-1.805) for C carrier vs. GG]. However, no association was found for rs5275, rs689466, rs5277 and rs2206593 in all comparison modes. This meta-analysis indicated that the COX-2 rs20417 polymorphism contributed to genetic susceptibility of breast cancer. In contrast, COX-2 rs5275, rs689466, rs2206593 and rs5277 polymorphisms might be not associated with the risk of breast cancer.

Association of the three common SNPs of cyclooxygenase-2 gene (rs20417, rs689466, and rs5275) with the susceptibility of breast cancer: an updated meta-analysis involving 34,590 subjects

Several single nucleotide polymorphisms have been identified in cyclooxygenase-2 (COX-2) genes (e.g., −765 G>C (rs20417), −1195G>A (rs689466), and 8473 C>T (rs5275)). The association of these SNPs with the risk of different cancer types is still controversial. This study aims to evaluate the correlation between these SNPs and breast cancer risk in different ethnic groups. We have searched PubMed, Web of Knowledge, and Embase for relevant studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate the strength of the associations. A total of 13 studies (15,330 cases and 19,260 controls) were eligible for meta-analysis. This meta-analysis showed that COX-2 rs20417 polymorphism was correlated with an increased risk of breast cancer in Caucasians, while rs689466 was associated with a decreased risk of breast cancer in Caucasians. The rs5275 polymorphism had no association with breast cancer risk.