Gastric cancer: epidemiologic aspects

Wnt10B is critical for the progression of gastric cancer

The family of Wnt proteins have been implicated in embryogenesis by regulation of cell fate and pattern formation, and also in human carcinogenesis. Wnt10B was previously shown to be involved in breast cancer development. The present study assessed the association of Wnt10B expression in human gastric cancer tissue specimens with clinicopathological data from these patients. Wnt10B expression in the regulation of gastric cancer cell proliferation and migration capacity in vitro was then investigated. The data revealed that Wnt10B mRNA and protein were upregulated in gastric cancer tissue samples and the upregulated Wnt10B mRNA was associated with gastric cancer metastasizing to lymph nodes. Knockdown of Wnt10B expression reduced gastric cancer cell proliferation and migration, as well as expression of a cell proliferation marker Ki67. Knockdown of Wnt10B expression inhibited tumor cell epithelial-mesenchymal transition by upregulation of E-cadherin and downregulation of N-cadherin. In addition, Wnt10B knockdown also suppressed tumor cell stemness by downregulation of octamer-binding transcription factor 4 and Nanog expression. The present data indicated that Wnt10B expression performs an important role in gastric cancer progression in vitro. Therefore, targeting of Wnt10B expression or activity may be investigated as a possible strategy for the control of gastric cancer.

Effectiveness of Citrus Fruits on Helicobacter pylori

It is known that Helicobacter pylori infection is associated with chronic gastritis, peptic ulcer, and gastric carcinoma. Due to the increased side effects of the treatment regimens and the development of antimicrobial resistance, a number of natural compounds have been tested as potential alternatives. In this review, we will examine the current knowledge on the effect of Citrus fruits and their derivatives against H. pylori, highlighting the remaining outstanding questions on the development of novel therapeutic strategies.

Effect of Endoscopic Gastroplication on the Genome-Wide Transcriptome in the Upper Gastrointestinal Tract

BACKGROUND

Bariatric surgery is an effective intervention strategy in obesity, resulting in sustained weight loss and a reduction of comorbidities. Gastroplication, using the articulating circular endoscopic stapler, was recently introduced as a transoral bariatric technique. This procedure reduces gastric volume and induced 34.9 % of excess weight loss in the first year (Paulus et al. Gastrointest Endosc. 81(2):312-20, 3). The aim of the present study was to gain insight in the long-term effects and underlying mechanisms of gastroplication by investigating differences in the genome-wide gastric and duodenal transcriptome before and 1 year after intervention.

METHODS

Ten morbidly obese patients (BMI 39.8 ± 0.9 kg/m2 (mean ± SEM)) underwent gastroplication. Previous to the procedure and after 1 year, blood samples were taken, and mucosal biopsies were collected from the fundus, antrum and duodenum. Gene expression was measured using microarray analysis. Plasma adiponectin, HbA1c, IL-1β, IL-6, IL-7, TNF-α, IFN-γ, MCP-1, IL-8, TGF-1 and CRP levels were determined.

RESULTS

Downregulation of inflammatory genes and gene sets was observed in the fundus and duodenum 1 year after surgery. Gene expression of ghrelin and its activating enzyme GOAT were downregulated in the upper gastrointestinal tract. Patients showed a reduction in plasma HbA1c levels (from 6.17 ± 0.51 to 5.32 ± 0.14 %, p = 0.004) and an increase of plasma adiponectin (from 16.87 ± 3.67 to 27.67 ± 5.92 μg/ml, p = 0.002).

CONCLUSIONS

Individuals undergoing gastroplication displayed a downregulation of inflammatory tone in the stomach and duodenum, which coincided with improved HbA1c and adiponectin levels. The reduction of inflammatory tone in the upper gastrointestinal tract may be a consequence of an improved metabolic health status or alternatively caused by the procedure itself.

A Review of the Antiviral Properties of Black Elder (Sambucus nigra L.) Products

Black elder (Sambucus nigra L.) has a long ethnobotanical history across many disparate cultures as a treatment for viral infection and is currently one of the most-used medicinal plants worldwide. Until recently, however, substantial scientific research concerning its antiviral properties has been lacking. Here, we evaluate the state of current scientific research concerning the use of elderberry extract and related products as antivirals, particularly in the treatment of influenza, as well as their safety and health impacts as dietary supplements. While the extent of black elder's antiviral effects are not well known, antiviral and antimicrobial properties have been demonstrated in these extracts, and the safety of black elder is reflected by the United States Food and Drug Administration approval as generally recognized as safe. A deficit of studies comparing these S. nigra products and standard antiviral medications makes informed and detailed recommendations for use of S. nigra extracts in medical applications currently impractical. Copyright © 2017 John Wiley & Sons, Ltd.

Association of Genetic Polymorphisms in the LncRNAs with Gastric Cancer Risk in a Chinese Population

Background: Genome-wide association studies have identified that polymorphisms in 8q24 confer susceptibility to gastric cancer. Polymorphisms in the lncRNA PRNCR1, PCAT1, and CCAT2 transcribed from the 8q24 locus have a potential risk for gastric cancer.

Methods: To evaluate whether there is such an association in Chinese population, a case-control study enrolled 494 patients and 494 healthy controls was carried out. Sequenom MassARRAY platform was used for genotyping.

Results: This study showed that rs16901946 G allele was associated with increased risk of gastric cancer (AG: adjusted OR = 1.33, 95% CI =1.02-1.73, p=0.033; GG: adjusted OR = 2.07; 95% CI = 1.11-3.86, p=0.023, AG/GG: adjusted OR = 1.39, 95% CI = 1.08-1.1.79, p=0.011; additive model: adjusted OR = 1.37; 95% CI = 1.10-1.70, p=0.004). Stratified analysis revealed that the increased risk was more evident in the cohort of younger subjects (adjusted OR = 1.84, 95% CI = 1.18-2.87, p=0.007), males (adjusted OR = 1.55, 95% CI = 1.15-2.08, p=0.004), positive Helicobacter pylori infection (adjusted OR = 1.44, 95% CI = 1.02-2.03, p=0.041), gastric cardia adenocarcinoma (adjusted OR = 1.61, 95% CI = 1.10-2.35, p=0.014), and tumor stage T1-T2 (adjusted OR = 1.58, 95% CI = 1.10-2.28, p=0.013).

Conclusions: Our study suggested that rs16901946 G allele carriers have an increased risk of gastric cancer, and the risk could be enhanced by the interactions between the polymorphism and age, sex, Helicobacter pylori infection.

Upregulation of T-cell Immunoglobulin and Mucin-Domain Containing-3 (Tim-3) in Monocytes/Macrophages Associates with Gastric Cancer Progression

T-cell immunoglobulin and mucin-domain containing-3 (Tim-3) is an important immune regulatory molecule in cancer immune system. However, expression and function of Tim-3 in monocytes/macrophages in cancer progression mainly remain unclear. In this study, we analyzed Tim-3 levels in peripheral blood mononuclear cells (PBMCs) from 62 gastric cancer patients and 45 healthy controls using flow cytometry and then associated Tim-3 levels with clinical pathological data from patients. We found Tim-3 level was significantly upregulated in monocytes from gastric cancer patients compared with those from healthy controls, and that upregulated Tim-3 levels associated with depth of tumor invasion and tumor lymph node metastasis and advanced clinical stages of gastric cancer patients. Furthermore, tumor-bearing mouse experiments revealed that Tim-3 level on monocytes/macrophages associated with xenograft formation and growth. In addition, culture of monocytes from healthy controls with gastric cancer cell-conditioned medium upregulated Tim-3 expression, but IL-10, TNF-α, IFN-γ, or GM-CSF treatment or T-bet, Eomes, and T-bet/Eomes double gene knockout did not affect Tim-3 levels in blood monocytes/macrophages from human or mouse, respectively. Gal-9/Tim-3 signal was able to significantly stimulate monocyte to secrete IL-6, IL-8, and IL-10, but not IL-1β, IL-12p70, or TNF-α in presence of LPS. In conclusion, our study demonstrated that Tim-3 expressed by monocyte/macrophages might be an important mechanism in gastric cancer progression.

Green tea polyphenols affect invasiveness of human gastric MKN-28 cells by inhibition of LPS or TNF-α induced Matrix Metalloproteinase-9/2

Several studies demonstrated a correlation between green tea consumption and a reduced cancer risk. Among different components, green tea polyphenols have been identified as molecules responsible for the beneficial effects showed by the green tea against oxidative stress and cell invasiveness. In this study, we investigated the effects of green tea polyphenol extracts (GTPs) in human gastric MKN-28 cell line. To this aim, we have first evaluated the effect of GTPs on oxidative stress induced cell injury. The pre-treatment with 10^-4 M catechin equivalents of GTPs exerts a protective effect on xanthine-xanthine oxidase induced cell cytotoxicity, thus confirming the anti-oxidant properties of GTPs. The effect of GTPs was also extended to the invasive ability of MKN-28 cells stimulated with TNF-α or LPS, as pro-inflammatory factors. Migration and matrigel invasion assays demonstrated that GTPs exposure (10^-6 M) prevents the increase in cell invasiveness induced by TNF-α or LPS. Finally, we have analyzed the effect of GTPs on the levels of Matrix Metalloproteinases (MMP)-9/2, whose expression is up-regulated by TNF-α or LPS. Our results indicated that the pre-treatment with GTPs was able to reduce MMP-9/2 expression at both protein and enzyme activity levels in the conditioned media of TNF-α or LPS stimulated MKN-28 cells. In conclusion, our results demonstrated that green tea polyphenol extract reduces the invasiveness of gastric MKN-28 cancer cells through the reduction of TNF-α or LPS induced MMP-9/2 up-regulation. Therefore, these data support the hypothesis that GTPs could exert a protective role against the metastatic process in gastric cancer.

Association between serum vitamin D levels and gastric cancer: A retrospective chart analysis

AIM

To determine whether there is an increased risk of gastric adenocarcinoma associated with vitamin D deficiency (VDd).

METHODS

A retrospective case control study was performed of all patients diagnosed with gastric adenocarcinoma between 2005 and 2015. After we excluded the patients without a documented vitamin D level, 49 patients were included in our study.

RESULTS

The average age of patients with gastric adenocarcinoma and documented vitamin D level was 64 years old (95%CI: 27-86) and average vitamin D level was 20.8 mg/dL (95%CI: 4-44). Compared to a matched control group, the prevalence of VDd/insufficiency in patients with gastric adenocarcinoma was significantly higher than normal vitamin D levels (83.7% vs 16.3%). Forty-one patients (83.7%) with adenocarcinoma showed VDd/insufficiency compared to 18 (37%) patients with normal vitamin D level without gastric cancer (OR: 8.8, 95%CI: 5-22, P value < 0.0001). The average age of males with gastric adenocarcinoma diagnosis was 60 years old vs 68 years old for females (P = 0.01). Stage II gastric adenocarcinoma was the most prevalent in our study (37%).

CONCLUSION

We reported a positive relationship between VDd and gastric adenocarcinoma, that is to say, patients with decreased VDd levels have an increased propensity for gastric adenocarcinoma.

Sinularin Induces Apoptosis through Mitochondria Dysfunction and Inactivation of the pI3K/Akt/mTOR Pathway in Gastric Carcinoma Cells

Sinularin is an active compound isolated from the cultured soft coral Sinularia flexibilis. In this study, we investigated the effects of sinularin on two human gastric cancer cell lines, AGS and NCI-N87. Our results demonstrated that sinularin suppressed the proliferation of gastric cancer cells in a dose-dependent manner and induced apoptosis. In addition, the loss of mitochondrial membrane potential, the release of cytochrome C, the activation of Bax, Bad and caspase-3/9, and the suppression of p-Bad, Bcl-xL and Bcl-2 were observed in the cells treated with sinularin. This finding suggests that sinularin-induced apoptosis is associated with mitochondria-mediated apoptosis and occurs through caspase-dependent pathways. Furthermore, sinularin inhibited the phosphoinositol 3-kinase/Akt/mechanistic target of the rapamycin signaling pathway. Taken together, our results show that sinularin-induced apoptosis is mediated by activation of the caspase cascade and mitochondrial dysfunction. Our findings suggest that sinularin merits further evaluation as a chemotherapeutic agent for human gastric cancer.

Detection of OSR2, VAV3, and PPFIA3 Methylation in the Serum of Patients with Gastric Cancer

Aim. This study was to evaluate the diagnostic value of OSR2, VAV3, and PPFIA3 hypermethylation in gastric cancer (GC) patients. Patients and Methods. By using methylation-specific polymerase chain reaction (MSP), we detected the methylation status in tissue and serum samples from 48 gastric cancer (GC) patients and 25 normal individuals. Results. We found that OSR2, VAV3, and PPFIA3 were methylated in 70.8% (34/48), 54.2% (26/48), and 60.4% (29/48) of GC tissue, respectively. On the contrary, those genes were barely methylated in their paired paracancerous histological normal tissues (PCHNTs) (all P values < 0.01). We next analyzed the methylated OSR2, VAV3, and PPFIA3 in serum DNA. Compared with 25 normal individuals, those three genes were significantly hypermethylated in GC patients serum samples (all P values < 0.01). Regarding their diagnostic value in serum samples, the combined sensitivity of at least one positive among the three markers in serum was 83.3%, with a specificity of 88%. Conclusion. Our test suggested that methylation of OSR2, VAV3, and PPFIA3 genes in serum sample may offer a good alternative in a simple, promising, and noninvasive detection of GC.

ALDH2 gene polymorphism in different types of cancers and its clinical significance

Aldehyde dehydrogenase 2 (ALDH2), an important mitochondrial enzyme governing ethanol metabolism, displays polymorphism in human. Recent evidence suggested that genetic polymorphism in ALDH2 gene may be significantly correlated with the susceptibility to cancer, such as colorectal cancer, esophageal cancer, and liver cancer. To investigate the correlation between ALDH2 mutant gene and the risk of a certain cancer, many studies have been done by testing the ALDH2 genotype in patients with cancers. Here, we summarized 84 ALDH2 gene single nucleotide polymorphism (SNP) sites in human cancer, which focus primarily on the rs671 SNP site. As a novel biological marker, ALDH2 displays a very attractive prospect in the screening, diagnosis and evaluation of the prognosis of many diseases. Moreover, much attention has been attracted to the studies of the biological functions and potential value of ALDH2 in the human cancer treatment. This review will provide an overview about the clinical prospects of ALDH2 based on the available information.

Identification of biomarkers for diagnosis of gastric cancer by bioinformatics

BACKGROUND

We aimed to discover potential gene biomarkers for gastric cancer (GC) diagnosis.

MATERIALS AND METHODS

Genechips of 10 GC tissues and 10 gastric mucosa (GM, para-carcinoma tissue, normal control) tissues were generated using an exon array of Affymetrix containing 30,000 genes. The differentially expressed genes (DEGs) between GC tissues and normal control were identified by the Limma package and analyzed by hierarchical clustering analysis. Gene ontology (GO) and pathway enrichment analyses were performed for investigating the functions of DEGs. Receiver operating characteristics (ROC) analysis was performed to measure the effects of biomarker candidates for diagnosis of GC.

RESULTS

Totals of 896 up-regulated and 60 down-regulated DEGs were identified to be differentially expressed between GC samples and normal control. Hierarchical clustering analysis showed that DEGs were highly differentially expressed and most DEGs were up-regulated. The most significantly enriched GO-BP term was revealed to be mitotic cell cycle and the most significantly enriched pathway was cell cycle. The intersection analysis showed that most significant DEGs were cyclin B1 (CCNB1) and cyclin B2 (CCNB2). The sensitivities and specificities of CCNB1 and CCNB2 were both high (p<0.0001). Areas under the ROC curve for CCNB1 and CCNB2 were both greater than 0.9 (p<0.0001).

CONCLUSIONS

CCNB1 and CCNB2, which were involved in cell cycle, played significant roles in the progression and development of GC and these genes may be potential biomarkers for diagnosis and prognosis of GC.

Filamin C, a dysregulated protein in cancer revealed by label-free quantitative proteomic analyses of human gastric cancer cells

Gastric cancer (GC) is the fourth and fifth most common cancer in men and women, respectively. We identified 2,750 proteins at false discovery rates of 1.3% (protein) and 0.03% (spectrum) by comparing the proteomic profiles of three GC and a normal gastric cell lines. Nine proteins were significantly dysregulated in all three GC cell lines, including filamin C, a muscle-specific filamin and a large actin-cross-linking protein. Downregulation of filamin C in GC cell lines and tissues were verified using quantitative PCR and immunohistochemistry. Data-mining using public microarray datasets shown that filamin C was significantly reduced in many human primary and metastasis cancers. Transient expression or silencing of filamin C affected the proliferation and colony formation of cancer cells. Silencing of endogenous filamin C enhanced cancer cell migration and invasion, whereas ectopic expression of filamin C had opposing effects. Silencing of filamin C increased the expression of matrix metallopeptidase 2 and improved the metastasis of prostate cancer in a zebrafish model. High filamin C associated with better prognosis of prostate cancer, leukemia and breast cancer patients. These findings establish a functional role of filamin C in human cancers and these data will be valuable for further study of its mechanisms.

MiR-101 inhibits cell growth and tumorigenesis of Helicobacter pylori related gastric cancer by repression of SOCS2

Several microRNAs (miRNA) have been implicated in H. pylori related gastric cancer (GC). However, the molecular mechanism of miRNAs in gastric cancer has not been fully understood. In this study, we reported that miR-101 is significantly down-regulated in H. pylori positive tissues and cells and in tumor tissues with important functional consequences. Ectopic expression of miR-101 dramatically suppressed cell proliferation and colony formation by inducing G1-phase cell-cycle arrest. We found that miR-101 strongly reduced the expression of SOCS2 oncogene in GC cells. Similar to the restoring miR-26 expression, SOCS2 down-regulation inhibited cell growth and cell-cycle progression, whereas SOCS2 over-expression rescued the suppressive effect of miR-101. Mechanistic investigations revealed that miR-101 suppressed the expression of c-myc, CDK2, CDK4, CDK6, CCND2, CCND3, and CCNE2, while promoted tumor suppressor p14, p16, p21 and p27 expression. In clinical specimens, SOCS2 was over-expressed in tumors and H. pylori positive tissues and its mRNA levels were inversely correlated with miR-101 expression. Taken together, our results indicated that miR-101 functions as a growth-suppressive miRNA in H. pylori related GC, and that its suppressive effects are mediated mainly by repressing SOCS2 expression.

Towards curative therapy in gastric cancer: Faraway, so close!

Although recent diagnostic and therapeutic advances have substantially improved the survival of patients with gastric cancer (GC), the overall prognosis is still poor. Surgery is the only curative treatment and should be performed in experienced centers. Due to high relapse following surgery, complementary and systemic treatment aimed at eradicating micrometastasis should be performed in most cases. Cytotoxic treatments are effective in downstaging locally advanced cancer, but different sensitivities and toxicities probably exist in different GC subtypes. Current treatment protocols are based primarily on clinical data and histological features, but molecular biomarkers that would allow for the prediction of treatment responses are urgently needed. Understanding how host factors are responsible for inter-individual variability of drug response or toxicity will also contribute to the development of more effective and less toxic treatments.

Evaluation of selected interleukins in patients with different gastric neoplasms: a preliminary report

Abnormal interactions between cytokines may be an overlooked mechanism linking the development of different types of gastric neoplasms. In this study a comprehensive analysis of the systemic levels of interleukins (IL-1,IL-6, IL-8,IL-10 and IL-12) was performed in 75 patients with different gastric neoplasms (cancer, gastrointestinal stromal tumors, neuroendocrine neoplasms, lymphomas) and 40 healthy volunteers. Patients with gastric cancer (GC) have significantly higher IL-6 levels, and lower IL-8 and IL-10 concentrations, in comparison to controls and patients with other gastric neoplasms. Analogous results were observed in terms of IL-6/IL-8 and IL-6/IL-10 ratios, whose values were also higher in GC patients. In GC patients no associations were detected between the systemic levels/values of interleukins (ratios) and TNM staging. IL-6, IL-10, IL-6/IL-8 and IL-6/IL-10 ratios appeared to hold diagnostic potential in confirming/excluding the presence of GC. Their sensitivity/specificity in GC detection/exclusion was approximately 54–72%. In conclusion, disturbed systemic biochemical balance in multiple interleukins exists at the earliest stages of and appears to be specific to GC. The interleukin ratios proposed here seem to be more promising indicators of GC in humans than direct systemic levels of interleukins, and probably possess the potential to be applied as a supporting factor for techniques routinely used.

Is there any relationship between food habits in the last two decades and gastric cancer in North-Western Iran?

PURPOSE

The aims of this case-control study were to assess the correlation between some food habits in the last two decades and gastric cancer in East Azerbaijan of Iran.

MATERIALS AND METHODS

In this hospital based case control study, 616 patients (212 gastric cancer patients, 404 cancer free patients) were recruited. Food habits of patients over the past two decades were assessed with a structured questionnaire. We used conditional logistic regression analysis for estimating crude and adjusted odds ratios (OR) and their respective 95% confidence intervals (95%CI).

RESULTS

In this study, over-eating, consumption of high fat milk and yogurt and especial types of cheese increased the risk of gastric cancer (All<0.05). Consumption of such especial cheeses such as Koze and Khiki increased the risk of gastric cancer by 12.6 fold (95% CI:1.99-79.36) and 7.36 fold (95% CI:1.33- 40.54), respectively. In addition, high fat food, moldy food, and pickled vegetables consumption as well as reuse of cooking oil for frying were significantly associated with gastric cancer risk. Furthermore, intake of Ghorme (deep fried meat) was positively correlated with gastric cancer risk (OR:1.31;95%CI: 0.91-1.87).

CONCLUSIONS

It can be confirmed that particular food habits which have been very common in East-Azerbaijan in the last two past decades increase risk of gastric cancer. According to our results and taking into account the long latency period of gastric cancer it can be concluded that nutrition education for a healthy diet should be performed from early childhood. However, further well designed cohort studies are needed to achieve more clear results.

Healthy lifestyle index and risk of gastric adenocarcinoma in the EPIC cohort study

Several modifiable lifestyle factors, including smoking, alcohol, certain dietary factors and weight are independently associated with gastric cancer (GC); however, their combined impact on GC risk is unknown. We constructed a healthy lifestyle index to investigate the joint influence of these behaviors on GC risk within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. The analysis included 461,550 participants (662 first incident GC cases) with a mean follow-up of 11.4 years. A healthy lifestyle index was constructed, assigning 1 point for each healthy behavior related to smoking status, alcohol consumption and diet quality (represented by the Mediterranean diet) for assessing overall GC and also body mass index for cardia GC and 0 points otherwise. Risk of GC was calculated using Cox proportional hazards regression models while adjusting for relevant confounders. The highest versus lowest score in the healthy lifestyle index was associated with a significant lower risk of GC, by 51% overall (HR 0.49 95% CI 0.35, 0.70), by 77% for cardia GC (HR 0.23 95% CI 0.08, 0.68) and by 47% for noncardia GC (HR 0.53 (95% CI 0.32, 0.87), p-trends<0.001. Population attributable risk calculations showed that 18.8% of all GC and 62.4% of cardia GC cases could have been prevented if participants in this population had followed the healthy lifestyle behaviors of this index. Adopting several healthy lifestyle behaviors including not smoking, limiting alcohol consumption, eating a healthy diet and maintaining a normal weight is associated with a large decreased risk of GC.

Association between polymorphisms in long non-coding RNA PRNCR1 in 8q24 and risk of gastric cancer

A long ncRNA (lncRNA) prostate cancer non-coding RNA 1 (PRNCR1) in the 8q24 has been reported to be upregulated in prostate cancer with a function of activating androgen receptor (AR). AR plays a key role in the gender disparity, cell migration, and invasion of gastric cancer (GC). We hypothesized that single nucleotide polymorphisms (SNPs) in the lncRNA PRNCR1 may be related to the risk of GC. We conducted a case-control study to investigate the association between SNPs in the lncRNA PRNCR1 and the risk of GC. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was used to determine the genotypes of 613 subjects including 219 cases with GC and 394 controls. We found that patients with the rs13252298AG genotype displayed a 1.50-fold increased risk of GC (AG vs. AA, 95 % confidence interval (CI) = 1.05-2.12, p = 0.02). Interestingly, the rs7007694CT and CC and the rs1456315GG genotypes displayed a decreased risk of GC (rs7007694CT vs. TT, odds ratio (OR) = 0.68, 95 % CI = 0.48-0.97, p = 0.03; rs7007694CC vs. TT, OR = 0.36, 95 % CI = 0.13-0.97, p = 0.04; rs1456315GG vs. AA, OR = 0.30, 95 % CI = 0.13-0.70, p = 0.004, respectively). Our results suggest that SNPs in the lncRNA PRNCR1 may be a biomarker for the etiology of GC.

Nucleotide variants of the cancer predisposing gene CDH1 and the risk of non-syndromic cleft lip with or without cleft palate

The CDH1 gene plays an important role during carcinogenesis and craniofacial morphogenesis. Germline mutations in this gene have been described in families presenting syndromic diffuse gastric cancer and orofacial clefts. The aim of this study was to evaluate the association between nucleotide variants of CDH1 and the risk of non-syndromic cleft lip with or without cleft palate (NSCL/P). Six single nucleotide polymorphisms (SNPs) of the CDH1 gene (rs16260, rs9929218, rs7186053, rs4783573, rs16958383, and rs1801552) were genotyped using the TaqMan SNP genotyping assays in 250 patients with NSCL/P and 540 controls from the Polish population. Comparison between patient and control groups showed that the CDH1 rs1801552 variant, under the assumption of recessive model, was associated with a two-fold decrease in the risk of NSCL/P (OR_{TT vs CT + CC} = 0.481, 95 % CI 0.281–0.824, p = 0.007). This association remained statistically significant even after the multiple testing correction. No significant associations with NSCL/P risk were found for the other five tested SNPs. We found a strong association between the cancer predisposing gene CDH1 and the risk of NSCL/P in the Polish population. This result, together with previous observations of co-occurrence of orofacial clefts and a variety of cancer types, suggests the need for replication studies testing rs1801552 in NSCL/P cohorts with a known cancer history.

Macronutrient intake and stomach cancer

PURPOSE

This study examines the association between intake of selected macronutrients and the risk of stomach cancer in a Northern American population.

METHODS

Mailed questionnaires were completed between 1994 and 1997 in eight Canadian provinces by 1,181 incident, histologically confirmed cases of stomach cancer and 5,039 population controls. Information on nutrient intake was obtained using a food frequency questionnaire. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were derived through unconditional logistic regression to adjust for potential confounders, including an estimate of total energy intake.

RESULTS

Intakes of total fat, saturated fat, and cholesterol were significantly associated with the risk of stomach cancer: The ORs for the highest versus the lowest quartile were 1.58 (95% CI 1.13-2.20), 1.86 (95% CI 1.37-2.52), and 1.75 (95% CI 1.36-2.25), respectively. Total fiber was inversely associated with stomach cancer (p = 0.03). The positive associations with intake of total fat and saturated fat were apparently stronger in women, overweight or obese subjects, and ever smokers. Saturated fat was specifically associated with increased risk of gastric cardia cancer, with an OR of 3.31 (95% CI 1.48-7.43).

CONCLUSIONS

A diet high in saturated fat appears to increase the risk of stomach cancer, particularly among obese subjects and for gastric cardia cancer.

Regular aspirin use and stomach cancer risk in China

OBJECTIVE

Epidemiological studies on aspirin and stomach cancer have been inconclusive. The purpose of our study was to investigate the association between aspirin and stomach cancer in China.

METHOD

A 1:2 matched case-control study was conducted in four large medical centers. A self-designed questionnaire was used to collect information. Unconditional logistic regression was used to compute crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs).

RESULT

Our study indicated that risk of stomach cancer was greatly reduced for regular aspirin user (OR = 0.62; 95% CI 0.42-0.80). Specifically, dosage and tablet-years of use were associated with lower risk (OR = 0.54; 95% CI 0.29-0.84 for ≥7 tabs/week; OR = 0.47; 95% CI 0.32-0.81 for ≥10 tablet years, respectively). Furthermore, the finding was strengthened by stratified studies of gender, smoking status, body mass index (BMI) and helicobacter pylori.

CONCLUSION

Our study confirmed that regular aspirin use is a protective factor to stomach cancer.

Tumor protein D52-like 2 accelerates gastric cancer cell proliferation in vitro

Tumor protein D52-like 2 (TPD52L2) has been commonly described as a protein involved in tumorigenesis, according to its name. However, its pathological function remains under investigation. In the present study, TPD52L2 was found to be widely expressed in several gastric cancer cell lines. An efficient knockdown of TPD52L2 by a specific short hairpin RNA (shRNA) loaded in lentivirus resulted in a remarkable reduction in cell proliferation in both MGC80-3 and SGC-7901 cell lines with high TPD52L2 expression, but a slight or little reduction in the proliferation of MKN-28 and AGS cells with low TPD52L2 expression. Further analysis by flow cytometry revealed that the cell cycle was primarily blocked in the G0/G1 phase, especially in the sub-G1 phase by TPD52L2 silencing, implying its possible roles in cell cycle control and apoptosis. Knockdown of TPD52L2 caused a cleavage of PARP in MGC80-3 cells. Their study suggests that TPD52L2 might promote gastric carcinogenesis, and could be a promising target with respect to developing new therapeutic strategies to treat gastric cancer.

Association of THBS1 rs1478605 T>C in 5'-untranslated regions with the development and progression of gastric cancer

Thrombospondin 1 (THBS1) plays an important role in angiogenesis and tumor progression. The aim of the present study was to investigate the effects of single-nucleotide polymorphisms (rs1478605 and rs3743125) in the untranslated regions of the THBS1 gene on the development and progression of gastric cancer. In the case-control study, 275 gastric cancer patients and 275 cancer-free controls were successfully genotyped using polymerase chain reaction-restriction fragment length polymorphism. The data demonstrated that THBS1 rs1478605 genotypic distributions significantly differed between the patient and control groups (P=0.005). Carriers of the CC genotype exhibited a decreased risk of developing gastric cancer compared to the carriers of the CT and TT genotypes [adjusted odd ratio (OR), 0.56; 95% confidence interval (CI), 0.39-0.79; P=0.001]. The CC genotype of rs1478605 was negatively associated with gastric cancer lymph node metastasis (OR, 0.41; 95% CI, 0.23-0.71; P=0.001) and was associated with a reduced risk of lymph node metastasis in male patients (OR, 0.27; 95% CI, 0.14-0.52; P<0.001). The THBS1 CT haplotype was associated with a reduced risk of developing gastric cancer (OR, 0.56; 95% CI, 0.33-0.93; P=0.02). By contrast, no association was observed between THBS1 rs3743125 and the development and progression of gastric cancer. These results suggest that THBS1 rs1478605 represents a potential molecular marker for gastric cancer.

At the crossroad between obesity and gastric cancer

Obesity has reached epidemic proportions worldwide with disproportionate prevalence in different communities and ethnic groups. Recently, the American Medical Association recognized obesity as a disease, which is a significant milestone that opens the possibilities of treating obesity under standardized health plans. Obesity is an inflammatory disease characterized by elevated levels of biomarkers associated with abnormal lipid profiles, glucose levels, and blood pressure that lead to the onset of metabolic syndrome. Interestingly, inflammatory biomarkers, in particular, have been implicated in the risk of developing several types of cancer. Likewise, obesity has been linked to esophageal, breast, gallbladder, kidney, pancreatic, and colorectal cancers. Thus, there exists a link between obesity status and tumor appearance, which may be associated to the differential levels and the circulating profiles of several inflammatory molecules. For example, mediators of the inflammatory responses in both obesity and gastric cancer risk are the same: pro-inflammatory molecules produced by the activated cells infiltrating the inflamed tissues. These molecules trigger pathways of activation shared by obesity and cancer. Therefore, understanding how these different pathways are modulated would help reduce the impact that both diseases, and their concomitant existence, have on society.

Let-7b inhibits cell proliferation, migration, and invasion through targeting Cthrc1 in gastric cancer

Dysregulation of specific microRNAs (miRNAs) is found to play a vital role in carcinogenesis and progression of gastric cancer (GC). In the present study, we investigated the expression profiles of miRNAs in gastric cancer. Let-7b was found downregulated remarkably in gastric cancer tissues and was correlated with Helicobacter pylori infection, tumor stage, and lymphatic metastasis. Ectopic expression of let-7b suppressed the growth, migration, invasion, and tumorigenicity of GC cells, whereas let-7b knockdown promoted these phenotypes. Bioinformatic analysis predicted collagen triple helix repeat containing 1 (Cthrc1) as a direct target of let-7b. Luciferase assay showed that let-7b repressed the activity of Cthrc1 through binding its 3'UTR. Western blotting also confirmed that the protein levels of Cthrc1 were decreased by let-7b. Cthrc1 was significantly upregulated and reversely correlated with let-7b levels in GC. Co-expression of let-7b and Cthrc1 without its 3'UTR could rescue cell growth, migration, and invasion inhibited by let-7b. These results suggest that let-7b may directly target Cthrc1 and function as a tumor suppressor gene in GC.

Genetic variation in C12orf51 is associated with prognosis of intestinal-type gastric cancer in a Chinese population

Recent genome-wide association study (GWAS) on esophageal squamous-cell carcinoma (ESCC) among Chinese population has identified two novel single nucleotide polymorphisms (SNPs) rs11066280 and rs2074356 on C12orf51 gene. We hypothesized that SNPs rs11066280 and rs2074356 could influence gastric cancer survival outcomes. We genotyped the SNPs rs11066280 and rs2074356 in 940 patients with surgically resected gastric cancer. Analyses of genotype association with survival outcomes were assessed by the Kaplan-Meier method, Cox proportional hazards models and the log-rank test. There was no significant association between rs11066280 and survival of gastric cancer. However, in the stratification analysis of histology, we found that the rs11066280 TA/AA genotypes were associated with a poor survival of intestinal-type gastric cancer (log-rank P=0.041, hazard ratio [HR]=1.40, 95% confidence interval [CI]=1.02-1.93), Moreover, this hazardous effect was more prominent among patients with tumor size>5cm, no distant metastasis, chemotherapy and drinking. No significant association was observed between rs2074356 and the survival of gastric cancer. C12orf5 rs11066280 could be useful marker of survival assessment and individualized clinical therapy for gastric cancer, particularly among the intestinal-type gastric cancer.

Helicobacter pylori: perspectives and time trends

The discovery of Helicobacter pylori three decades ago is a modern medical success story. It markedly changed our understanding of the pathophysiology of gastroduodenal diseases and led to an improvement in the treatment of diseases related to H. pylori infection. Many of these diseases (such as ulcer disease and mucosal associated lymphoid tissue lymphoma) have become curable, and others (gastric cancer) might be preventable with the application of H. pylori eradication therapy. Since its discovery, H. pylori has also been identified as a trigger for some extragastric diseases. Promising results in this exciting field might have a clinical effect in the near future. This Timeline gives an overview of the success of clinical research on H. pylori to date and highlights some future trends in this area.

Screening of susceptibility genes and multi-gene risk analysis in gastric cancer

The aim of the study was to explore the relations between the genetic polymorphism and the susceptibility to the gastric cancer in Chinese Han population, and to analyze the multi-genes risk in the development of gastric carcinoma. A case-control study of 1:1 matching was performed on 564 individuals with primary gastric carcinoma in Nanjing, China. The genotypes of CYP2E1, GSTMl, GSTTl, NAT2, ALDH2, MTHFR, XRCCl, IL-1β, VDR, and TNF were detected by molecular biological techniques (PCR-RFLP and AS-PCR). Sole gene and gene-gene interactions were analyzed using Logistic regression model. The effect of multi-genes on gastric carcinoma was analyzed using multi-gene risk analysis model, which focused on the effect of multi-gene interaction on the development of gastric carcinoma. The genotypes involved in the susceptibility of gastric carcinoma were CYP2E1(c1/c1), NAT2M1(T/T), NAT2M2(A/A), XRCC1194(T/T), NAT2 phenotype (slow acetylator), MTHFR1298(A/C), and VDR TaqI(T/T), respectively. Multi-gene risk analysis model was introduced to analyze the effect of these genes on the gastric carcinoma. The results showed that there was a strong relation between odds ratio (OR) value of polygene combination and the gene frequency. With the increase of susceptibility gene frequency, the risk distribution curve of gastric carcinoma would shift to a more dangerous phase and exhibit a quantitative relation. Our results demonstrated that the OR of each gene can be utilized as an index to assess the effect of multiple susceptible genes on the occurrence of gastric carcinoma.

Perspectives on new biomarkers in gastric cancer: Diagnostic and prognostic applications

Gastric cancer is considered one of the most deadly tumors worldwide. Even with the decline in its incidence, the mortality rate of this disease has remained high, mainly due to its late diagnosis and to the lack of precise prognostic markers. The main purpose of this review is to present genetic, epigenetic and proteomic molecular markers that may be used in a diagnostic and prognostic manner and to discuss the pros and cons of each type of marker for improving clinical practice. In this sense, we observed that the use of genetic markers, especially mutations and polymorphisms, should be carefully considered, as they are strongly affected by ethnicity. Proteomic-based markers show promise, but the higher costs of the associated techniques continue to make this approach expensive for routine use. Alternatively, epigenetic markers appear to be very promising, as they can be detected in bodily fluids as well as tissues. However, such markers must be used carefully because epigenetic changes may occur due to environmental factors and aging. Despite the advances in technology and its access, to date, there are few defined biomarkers of prognostic and diagnostic use for gastric tumors. Therefore, the use of a panel of several approaches (genetic, epigenetic and proteomic) should be considered the best alternative for clinical practice.

Infection and esophageal cancer

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on infection and cancer, and includes commentaries on the influence of bacterial infections on mucin expression and cancer risk; the role of esophageal bacterial biota in the incidence of esophageal disease; the association between human papilloma virus (HPV) and esophageal squamous cell carcinoma; the role of HPV in esophageal adenocarcinoma; the role of Helicobacter pylori in cardiac carcinoma; and the role of Epstein-Barr virus infection in esophageal cancer.

Elevated plasma visfatin levels correlate with poor prognosis of gastric cancer patients

Visfatin is a proinflammmatory cytokine with accumulating evidence for its rise in circulation of cancer patients. This study aimed to evaluate the relationship between preoperative plasma visfatin level and prognosis of gastric cancers. Preoperative plasma visfatin levels of 262 patients with gastric cancers and plasma visfatin levels of 262 healthy individuals were determined using enzyme-linked immunosorbent assay. Preoperative plasma visfatin level was substantially higher in patients than in healthy subjects. Plasma visfatin levels were associated with invasion depth, lymph node metastasis, distant metastasis, peritoneal dissemination, tumor size and tumor node metastasis stage. Multivariate analysis revealed that high plasma visfatin level was an independent factor for death. Receiver operating characteristic curve analysis showed that plasma visfatin level predicted death with high area under curve. Multivariate Cox regression analysis identified plasma visfatin level as an independent predictor of overall survival. Thus, our results suggest that high preoperative plasma visfatin level is associated with prognostic factors for gastric cancer as well as may play a role as prognostic biomarker in gastric cancer survival.

Clinical features of low-grade gastric intraepithelial neoplasia

AIM: To analyze the clinical features of low-grade gastric intraepithelial neoplasia (LGIN).

METHODS: A total of 866 patients pathologically diagnosed with LGIN by endoscopy and gastric biopsy between 2010 and 2013 were recruited. Endoscopic presentations, intestinal metaplasia and the relationship with Helicobacter pylori (H. pylori) infection were investigated.

RESULTS: Endoscopic presentations of LGIN were diverse and gastric mucosal erosion was most frequently seen. LGIN was most frequently detected in patients at the age between 39 to 49 years (42.73%) and in men. LGIN was mostly located in the gastric antrum. The rate of H. pylori infection was significantly higher in patients with LGIN at the antrum than at other sites (P < 0.05). The positive rate of intestinal metaplasia was significantly higher in patients at the age between 55-70 years than between 39-54 years (P < 0.01). The positive rate of intestinal metaplasia was significantly higher in patients with LGIN at the gastric angularis than at the gastric antrum, corpus or cardia (P < 0.01). ¹⁴C-UBT value positively correlated with the positive rate of intestinal metaplasia (r = 0.105, P = 0.002).

CONCLUSION: The incidence of LGIN correlates with age, gender, tumor location and Helicobacter pylori infection.

Body mass index and cancer incidence: the FINRISK study

The relation between body mass index (BMI) and risk of cancer incidence is controversial. Cancer incidence during 1972-2008 in relation to BMI was investigated in a prospective cohort of 54,725 Finns aged 24-74 years and free of cancer at enrollment. Over a mean follow-up of 20.6 years, 8,429 (15.4%) incident cancers were recorded, 4,208 (49.9%) from men. Both parametric and nonparametric approaches were used to evaluate the shape of the relationship between BMI and incidence of cancer. BMI had a linear positive association with incidence of cancers of the colon, liver, kidney, bladder and all sites combined in men, and of cancers of the stomach, colon, gallbladder and ovary in women, an inverse association with incidence of cancers of the lung in men and the lung and breast in women, a J-shaped association with incidence of all cancers combined in women. High BMI in women was associated with an increased overall cancer risk in never smokers but a reduced risk in smokers. Elevated BMI was associated with an increased risk of incidence of cancers of certain sites.

Clinicopathological features and trend changes of gastric carcinoma in Southern China

AIM: To investigate the clinicopathological features of gastric carcinoma in southern China and disease trends changes over the last 18 years.

METHODS: We designed a retrospective study in the Department of Gastrointestinal Surgery, the first affiliated hospital, Sun Yat-sen University. A total of 2100 adult patients with definitely diagnosed, histologically proven gastric carcinomas treated with radical gastrectomy from 1994 to 2013 were examined retrospectively. In all cases patient age, gender, tumor location, Borrmann type, histopathological type and grade, and pTNM stage were identified and recorded. The information was obtained from hospital records. The data were analyzed with Stata12.0 software.

RESULTS: In this study, the mean age of patients was 57 years with a range from 19-89 years. A higher incidence was found in patients over 60 years of age. In the study population, 67.38% of patients were male and 32.62% were female. Women had a higher disease incidence than men in patients less than 40 years of age (P < 0.001). No obvious change of patient age and gender was observed in the last 18 years. The rates of disease by location were the following: antrum (44.57%), followed by fundus/ body (24.95%) and cardia/gastroesophageal junction (23.00%). The mean tumor diameter was 5.57 cm, and advanced gross type Borrmann III was most common. Most patients were at advanced stages when first diagnosed, and patients with early stage disease were relatively rare. More early stage patients were detected in recent years, especially after 2000 (P < 0.001). Gastric carcinoma has different features in young and old patients. The young patients had the following features: more frequently female, tumors in the antrum, larger tumor size, poorly differentiated carcinoma, high rate of metastasis to other sites and advanced stages (P < 0.05).

CONCLUSION: In southern China, gastric carcinoma was more frequent in old men and young women. Young and old patients should be treated differently for having different features.

ALDH2 and ADH1 genetic polymorphisms may contribute to the risk of gastric cancer: a meta-analysis

AIM

We conducted a meta-analysis of case-control studies to determine whether ALDH2, ADH1 and ADH2 genetic polymorphisms contribute to the pathogenesis of gastric cancer.

METHODS

The PubMed, CISCOM, CINAHL, Web of Science, Google Scholar, EBSCO, Cochrane Library, and CBM databases were searched for relevant articles published before November 1st, 2013 without any language restrictions. Meta-analysis was conducted using the STATA 12.0 software. We calculated crude odds ratios (ORs) with their 95% confidence intervals (95%CI) to evaluate their relationships under five genetic models. Seven case-control studies with a total of 2,563 gastric cancer patients and 4,192 healthy controls met the inclusion criteria. Nine common polymorphisms were evaluated, including rs671, rs16941667 and rs886205 in the ALDH2 gene, rs1230025, rs13123099, rs698 and rs1693482 in the ADH1 gene, and rs1229984 and rs17033 in the ADH2 gene.

RESULTS

The results of our meta-analysis suggested that ALDH2 genetic polymorphisms might be strongly correlated with an increased risk of gastric cancer (allele model: OR = 1.21, 95%CI: 1.11 ∼ 1.32, P<0.001; dominant model: OR = 1.23, 95%CI: 1.09 ∼ 1.39, P = 0.001; respectively), especially for rs671 polymorphism. Furthermore, we observed significant associations between ADH1 genetic polymorphisms and an increased risk of gastric cancer (allele model: OR = 1.21, 95%CI: 1.08 ∼ 1.36, P = 0.001; dominant model: OR = 10.52, 95%CI: 3.04 ∼ 36.41, P<0.001; respectively), especially for rs1230025 polymorphism. Nevertheless, no positive relationships were found between ADH2 genetic polymorphisms and gastric cancer risk (all P>0.05).

CONCLUSION

The current meta-analysis suggests that ALDH2 and ADH1 genetic polymorphisms may play crucial roles in the pathogenesis of gastric cancer. However, ADH2 genetic polymorphisms may not be important dominants of susceptibility to gastric cancer.