Detection and Clinical Significance of COX-2 Gene SNPs in Gastric Cancer. Cell Biochem Biophys. 2015;72:657-660. [PMID: 27352184 DOI: 10.1007/s12013-014-0465-8]

SLC39A10 promotes malignant phenotypes of gastric cancer cells by activating the CK2-mediated MAPK/ERK and PI3K/AKT pathways

Solute carrier family 39 member 10 (SLC39A10) belongs to a subfamily of zinc transporters and plays a key role in B-cell development. Previous studies have reported that its upregulation promotes breast cancer metastasis by enhancing the influx of zinc ions (Zn2+); however, its role in gastric cancer remains totally unclear. Here, we found that SLC39A10 expression was frequently increased in gastric adenocarcinomas and that SLC39A10 upregulation was strongly associated with poor patient outcomes; in addition, we identified SLC39A10 as a direct target of c-Myc. Functional studies showed that ectopic expression of SLC39A10 in gastric cancer cells dramatically enhanced the proliferation, colony formation, invasiveness abilities of these gastric cancer cells and tumorigenic potential in nude mice. Conversely, SLC39A10 knockdown inhibited gastric cancer cell proliferation and colony formation. Mechanistically, SLC39A10 exerted its carcinogenic effects by increasing Zn2+ availability and subsequently enhancing the enzyme activity of CK2 (casein kinase 2). As a result, the MAPK/ERK and PI3K/AKT pathways, two major downstream effectors of CK2, were activated, while c-Myc, a downstream target of these two pathways, formed a vicious feedback loop with SLC39A10 to drive the malignant progression of gastric cancer. Taken together, our data demonstrate that SLC39A10 is a functional oncogene in gastric cancer and suggest that targeting CK2 is an alternative therapeutic strategy for gastric cancer patients with high SLC39A10 expression.

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.

Genetic Variations in Prostaglandin E2 Pathway Identified as Susceptibility Biomarkers for Gastric Cancer in an Intermediate Risk European Country

The cyclooxygenase-2 (COX-2)/prostaglandin E₂ (PGE₂) pathway exerts deleterious pleiotropic effects in inflammation-induced gastric carcinogenesis. We aimed to assess the association of genetic variants in prostaglandin-endoperoxide synthase 2 (PTGS2), ATP binding cassette subfamily C member 4 (ABCC4), hydroxyprostaglandin dehydrogenase 15-(NAD) (HPGD), and solute carrier organic anion transporter family member 2A1 (SLCO2A1) PGE₂ pathway-related genes with gastric cancer (GC) risk in a European Caucasian population. A hospital-based case-control study gathering 260 GC cases and 476 cancer-free controls was implemented. Using a tagSNP approach, 51 single nucleotide polymorphisms (SNPs) were genotyped through MassARRAY^® iPLEX Gold Technology or allelic discrimination by real-time polymerase chain reaction (PCR). Homozygous carriers of the minor allele for both rs689466 and rs10935090 SNPs were associated with a 2.98 and 4.30-fold increased risk for GC, respectively (95% confidence interval (CI): 1.14–7.74, p = 0.027; 95% CI: 1.22–15.16, p = 0.026), with the latter also being associated with an anticipated diagnosis age. A multifactor dimensionality reduction analysis identified an overall three-factor best interactive model composed of age, rs689466, and rs1678374 that was associated with a 17.6-fold GC increased risk (95% CI: 11.67–26.48, p < 0.0001, (cross-validation) CV consistency of 8/10 and accuracy of 0.807). In this preliminary study, several tagSNPs in PGE₂ pathway-related genes were identified as risk biomarkers for GC development. This approach may help to identify higher-risk individuals and may contribute to the tailoring screening of GC in intermediate-risk European countries.

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.

Identification of a prognostic 5-Gene expression signature for gastric cancer

PURPOSE

Gastric cancer (GC) is a major tumor throughout the world with remaining high morbidity and mortality. The aim is to generate a gene model to assess the prognoses risk of patients with GC.

METHODS

Gene expression profiling of gastric cancer patients, GSE62254 (300 samples) and GSE26253 (432 samples), was downloaded from Gene Expression Omnibus (GEO) database. Univariate survival analysis and LASSO (Least Absolute Shrinkage and Selectionator operator) (1000 iterations) of differentially expressed genes in GSE62254 was assessed using survival and glmnet in R package, respectively. Kaplan-Meier analysis on the clustering algorithm from each regression model was performed to calculate the influence to the prognosis. Random samples in GSE26253 were analyzed in multivariate and univariate survival analysis for one thousand times to calculate statistical stability of each regression model.

RESULTS

A total of 854 Genes were identified differentially expressed in GSE62254, among which 367 Genes were found influencing the prognoses. Six gene clusters were selected with good stability. Hereinto, five or more genes in 11-Gene model, TRPC1, SGCE, TNFRSF11A, LRRN1, HLF, CYS1, PPP1R14A, NOV, NBEA, CES1 and RGN, was available to evaluate the prognostic risk of GC patients in GSE26253 (P = 0.00445). The validity and reliability was validated.

CONCLUSION

In conclusion, we successfully generated a stable 5-Gene model, which could be utilized to predict prognosis of GC patients and would contribute to postoperational treatment and follow-up strategies.

Association between COX-2 -1195G>A polymorphism and gastrointestinal cancer risk: A meta-analysis

AIM

To perform a meta-analysis to investigate the association between cyclooxygenase-2 (COX-2) -1195G>A gene polymorphism and gastrointestinal cancers.

METHODS

Publications related to the COX-2 -1195G>A gene polymorphism and gastrointestinal cancers published before July 2016 were retrieved from PubMed, EMBASE, Web of Science, China Biological Medicine Database, China National Knowledge Infrastructure, and CQVIP Database. Meta-analysis was performed using Stata11.0 software. The strength of the association was evaluated by calculating the combined odds ratios (ORs) and the corresponding 95%CIs. The retrieved publications were excluded or included one by one for sensitivity analysis. In addition, the funnel plot, Begg’s rank correlation test, and Egger’s linear regression method were applied to analyse whether the included publications had publication bias.

RESULTS

A total of 24 publications related to the COX-2 -1195G>A gene polymorphism were included, including 28 studies involving 11043 cases and 18008 controls. The meta-analysis results showed that the COX-2 -1195G>A gene polymorphism significantly correlated with an increased risk of gastrointestinal cancers, particularly gastric cancer (A vs G: OR = 1.35; AA/AG vs GG: OR = 1.54; AA vs GG/AG: OR = 1.43; AA vs GG: OR = 1.80; AG vs GG: OR = 1.35). Compared to the Caucasian population in America and Europe, the COX-2 -1195G>A gene polymorphism in the Asian population (A vs G: OR = 1.30; AA/AG vs GG: OR = 1.50; AA vs GG/AG: OR = 1.35; AA vs GG: OR = 1.71; AG vs GG: OR = 1.37) significantly increased gastrointestinal cancer risk. The sensitivity analysis (P < 0.05) and the false positive report probability (P < 0.2) confirmed the reliability of the results.

CONCLUSION

The results showed that the COX-2 -1195G>A gene polymorphism might be a potential risk factor for gastrointestinal cancers. Further validation by a large homogeneous study is warranted.