Gastric cancer: epidemiologic aspects

A Bifidobacterium animalis subsp. lactis strain that can suppress Helicobacter pylori: isolation, in vitro and in vivo validation

The administration of probiotics is an effective approach for treatment of Helicobacter pylori, which is associated with human gastrointestinal diseases and cancers. To explore more effective probiotics for H. pylori infection elimination, bacteria from infant feces were screened in this study. We successfully isolated the Bifidobacterium animalis subsp. lactis strains and evaluated its efficacy to inhibit H. pylori growth in vitro and in vivo. The results showed that a B. animalis strain (named BB18) sustained a high survival rate after incubation in gastric juice. The rapid urease test suggested that B. animalis BB18 reduced pathogen loads in H. pylori-infected Mongolian gerbils. Alleviation of H. pylori infection-induced gastric mucosa damage and decreased levels inflammatory cytokines were observed after the B. animalis BB18 administration. These findings demonstrated that B. animalis BB18 can inhibit H. pylori infection both in vitro and in vivo, suggesting its potential application for the prevention and eradication therapy of H. pylori infection.

Lifestyle habits and gastric cancer in an East Asian population: a Mendelian randomization study

Background

Epidemiological evidence suggests an association between lifestyle habits (smoking, alcohol consumption, tea, coffee intake, etc.) and gastric cancer (GC). However, the causal relationship remains uncertain. Therefore, the purpose of this study was to ascertain whether there is a causal connection between them.

Methods

Two-sample Mendelian randomization (MR) analysis was performed using the publicly available Genome Wide Association Study summary datasets using six methods: inverse variance weighting (IVW), weighted median, MR using a Robust Adjusted Profile Score (MR.Raps), MR using a Robust Adjusted Profile Score (MR-PRESSO), Radial regression of MR, and Causal Analysis Using Summary Effect Estimates (CAUSE). A sensitivity analysis was conducted to assess the robustness of the results.

Results

In an East Asian population, we found that increased tea intake reduced the risk of GC [odds ratio (OR)= 0.90, 95% confidence interval (CI)= 0.82-0.99, P = 0.037] while there was a positive association between smoking and GC (OR = 1.58, 95% CI = 1.04-2.39, P = 0.032). No causal relationship between alcohol and coffee intake and GC. Sensitivity analyses demonstrated the robustness of these causal associations.

Conclusions

Our study suggests that tea intake may reduce the risk of GC, for which smoking is a potential risk factor. Nevertheless, a larger and more diverse sample size is needed for further validation.

Toxic mechanisms of cadmium and exposure as a risk factor for oral and gastrointestinal carcinomas

Incidence and mortality rates of gastrointestinal (GI) and oral cancers are among the highest in the world, compared to other cancers. GI cancers include esophageal, gastric, colon, rectal, liver, and pancreatic cancers, with colorectal cancer being the most common. Oral cancer, which is included in the head and neck cancers category, is one of the most important causes of death in India. Cadmium (Cd) is a toxic element affecting humans and the environment, which has both natural and anthropogenic sources. Generally, water, soil, air, and food supplies are reported as some sources of Cd. It accumulates in organs, particularly in the kidneys and liver. Exposure to cadmium is associated with different types of health risks such as kidney dysfunction, cardiovascular disease, reproductive dysfunction, diabetes, cerebral infarction, and neurotoxic effects (Parkinson's disease (PD) and Alzheimer's disease (AD)). Exposure to Cd is also associated with various cancers, including lung, kidney, liver, stomach, hematopoietic system, gynecologic and breast cancer. In the present study, we have provided and summarized the association of Cd exposure with oral and GI cancers.

Comprehensive Analysis of Stromal and Serum Markers in Gastric Cancer

A comprehensive analysis of the cell phenotype of the inflammatory infiltrate of the tumor stroma represents a promising area of molecular oncology. The study of not only soluble forms of various immunoregulatory molecules, but also their membrane-bound forms is also considered highly relevant. We performed a comprehensive analysis of tissue and circulating forms of the PD-1 and PD-L1 proteins, as well as macrophage and B-cell markers in the tumor stroma of gastric cancer, to assess their clinical and prognostic significance. The tumor and blood plasma samples from 63 gastric cancer patients were studied using ELISA and immunohistochemistry. Malignant gastric tumors were shown to be strongly infiltrated by B-cells, and their number was comparable to that of macrophages. For PU.1 expression, an association with tumor size was observed; i.e., larger tumors were characterized by fewer PU.1+ infiltrating cells (p = 0.005). No clinical significance was found for CD20 and CD163, but their numbers were higher at earlier stages of the disease and in the absence of metastases. It was also demonstrated that the PD-L1 content in tumor cells was not associated with the clinical and morphological characteristics of GC. At the same time, PD-L1 expression in tumor stromal cells was associated with the presence of distant metastases. The analysis of the prognostic significance of all the markers studied demonstrated that CD163 was statistically significantly associated with a poor prognosis for the disease (p = 0.019). In addition, PD-L1 expression in tumor cells tended to indicate a favorable prognosis (p = 0.122). The results obtained in this work indicate that the study of soluble and tissue markers of tumor stroma is promising in prognosticating the course of GC. The search for combinations of markers seems to be highly promising, with their comprehensive analysis capable of helping personalize advanced antitumor therapy.

A prognostic signature of pyroptosis-related lncRNAs verified in gastric cancer samples to predict the immunotherapy and chemotherapy drug sensitivity

Background: Pyroptosis is a recently identified mode of programmed inflammatory cell death that has remarkable implications for cancer development. lncRNAs can be involved in cellular regulation through various pathways and play a critical role in gastric cancer (GC). However, pyroptosis -related lncRNAs (PRlncRNAs) have been rarely studied in GC.

Methods: Pyroptosis-related gene were abstracted from the literature and GSEA Molecular Signatures data resource. PRlncRNAs were obtained using co-expression analysis. LASSO Cox regression assessment was employed to build a risk model. Kaplan-Meier (KM), univariate along with multivariate Cox regression analysis were adopted to verify the predictive efficiency of the risk model in terms of prognosis. qRT-PCR was adopted to validate the expression of PRlncRNAs in GC tissues. In addition, immune cell infiltration assessment and ESTIMATE score evaluation were adopted for assessing the relationship of the risk model with the tumor immune microenvironment (TME). Finally, immune checkpoint gene association analysis and chemotherapy drug sensitivity analysis were implemented to assess the worthiness of our risk model in immunotherapy and chemotherapy of GC.

Results: We identified 3 key PRlncRNAs (PVT1, CYMP-AS1 and AC017076.1) and testified the difference of their expression levels in GC tumor tissues and neighboring non-malignant tissues (p < 0.05). PRlncRNAs risk model was able to successfully estimate the prognosis of GC patients, and lower rate of survival was seen in the high-GC risk group relative to the low-GC risk group (p < 0.001). Other digestive system tumors such as pancreatic cancer further validated our risk model. There was a dramatic difference in TMB level between high-GC and low-GC risk groups (p < 0.001). Immune cell infiltration analysis and ESTIMATE score evaluation demonstrated that the risk model can be adopted as an indicator of TME status. Besides, the expressions of immunodetection site genes in different risk groups were remarkably different (CTLA-4 (r = −0.14, p = 0.010), VISTA (r = 0.15, p = 0.005), and B7-H3 (r = 0.14, p = 0.009)). PRlncRNAs risk model was able to effectively establish a connection with the sensitivity of chemotherapeutic agents.

Conclusion: The 3 PRlncRNAs identified in this study could be utilized to predict disease outcome in GC patients. It may also be a potential therapeutic target in GC therapy, including immunotherapy and chemotherapy.

Ursolic acid silences CYP19A1/aromatase to suppress gastric cancer growth

INTRODUCTION

Gastric cancer (GCa) is a malignancy with few effective treatments. Ursolic acid (UA), a bioactive triterpenoid enriched in Hedyotis diffusa Willd, known to suppress GCa without identified target. CYP19A1 (cytochrome P450 family 19A1; also known as aromatase, Ar) was correlated to GCa prognosis. Relatedly, Ar silencers, which halt the expression of Ar exhibited anti-GCa effects in experimental models, are currently being investigated.

METHOD

The docking simulation score of UA was compared with Ar inhibitors, e.g., letrozole, exemestane, in Ar protein crystallization. Hedyotis diffusa Willd ethanol extract, UA, or 5-fluracil were applied onto AGS, SC-M1, MKN45 GCa cells for cancer inhibition tests. Immunoblot for measuring gene expressions upon drug treatments, or gene knockdown/overexpression. Treatments were also applied in a MKN45 implantation tumor model. A web-based GCa cohort for Ar expression association with prognosis was performed.

RESULT

The ethanol extracts of Hedyotis diffusa Willd, enrich with UA, exhibited cytotoxic activity against GCa cells. Molecular docking simulations with the 3D Ar structure revealed an excellent fitting score for UA. UA increase cytotoxic, and suppressed colony, in addition to its Ar silencing capacity. Moreover, UA synergistically facilitated 5-FU, (a standard GCa treatment) regimen in vitro. Consistent with those results, adding estradiol did not reverse the cancer-suppressing effects of UA, which confirmed UA acts as an Ar silencer. Furthermore, UA exhibited tumor-suppressing index (TSI) score of 90% over a 6-week treatment term when used for single dosing in xenograft tumor model. In the clinical setting, Ar expression was found to be higher in GCa tumors than normal parental tissue from the TCGA (The Cancer Genome Atlas) cohort, while high Ar expression associated with poor prognosis. Together, the results indicate UA could be used to treat GCa by silencing Ar expression in GCa. Hedyotis diffusa Willd ethanol extract could be an functional food supplements.

Inverse Association between Dietary Iron Intake and Gastric Cancer: A Pooled Analysis of Case-Control Studies of the Stop Consortium

Background: Inconsistent findings have been reported regarding the relationship between dietary iron intake and the risk of gastric cancer (GC). Methods: We pooled data from 11 case-control studies from the Stomach Cancer Pooling (StoP) Project. Total dietary iron intake was derived from food frequency questionnaires combined with national nutritional tables. We derived the odds ratios (ORs) and 95% confidence intervals (CIs) for quartiles of dietary iron through multivariable unconditional logistic regression models. Secondary analyses stratified by sex, smoking status, caloric intake, anatomical subsite and histological type were performed. Results: Among 4658 cases and 12247 controls, dietary iron intake was inversely associated with GC (per quartile OR 0.88; 95% CI: 0.83-0.93). Results were similar between cardia (OR = 0.85, 95% CI = 0.77-0.94) and non-cardia GC (OR = 0.87, 95% CI = 0.81-0.94), and for diffuse (OR = 0.79, 95% CI = 0.69-0.89) and intestinal type (OR = 0.88, 95% CI = 0.79-0.98). Iron intake exerted an independent effect from that of smoking and salt intake. Additional adjustment by meat and fruit/vegetable intake did not alter the results. Conclusions: Dietary iron is inversely related to GC, with no difference by subsite or histological type. While the results should be interpreted with caution, they provide evidence against a direct effect of iron in gastric carcinogenesis.

Pan-Cancer Single-Cell Analysis Reveals the Core Factors and Pathway in Specific Cancer Stem Cells of Upper Gastrointestinal Cancer

Upper gastrointestinal cancer (UGIC) is an aggressive carcinoma with increasing incidence and poor outcomes worldwide. Here, we collected 39,057 cells, and they were annotated into nine cell types. By clustering cancer stem cells (CSCs), we discovered the ubiquitous existence of sub-cluster CSCs in all UGICs, which is named upper gastrointestinal cancer stem cells (UGCSCs). The identification of UGCSC function is coincident with the carcinogen of UGICs. We compared the UGCSC expression profile with 215,291 single cells from six other cancers and discovered that UGCSCs are specific tumor stem cells in UGIC. Exploration of the expression network indicated that inflammatory genes (CXCL8, CXCL3, PIGR, and RNASE1) and Wnt pathway genes (GAST, REG1A, TFF3, and ZG16B) are upregulated in tumor stem cells of UGICs. These results suggest a new mechanism for carcinogenesis in UGIC: mucosa damage and repair caused by poor eating habits lead to chronic inflammation, and the persistent chronic inflammation triggers the Wnt pathway; ultimately, this process induces UGICs. These findings establish the core signal pathway that connects poor eating habits and UGIC. Our system provides deeper insights into UGIC carcinogens and a platform to promote gastrointestinal cancer diagnosis and therapy.

Transcriptome sequencing and flavonoid metabolism analysis in the leaves of three different cultivars of Acer truncatum

Young and mature leaves of three Acer truncatum varieties with different leaf colors were examined. Transcriptome sequencing and flavonoid metabolism were used to analyze the differential gene expression associated with different leaf colors and growth stages and the relationships between gene expression and flavonoid and anthocyanin contents to improve ornamental value and develop flavonoid-rich A. truncatum. Kyoto Encyclopedia of Genes and Genomes database annotation of differentially expressed genes indicated that the following genes were related to flavonoid synthesis: phenylpropanoid biosynthesis genes (PAL, C4H, 4CL and CHS), flavonoid biosynthesis genes (E2.1.1.104, CHI, FLS, F3'5'H and ANR), anthocyanin biosynthesis genes (ANS, DFR, HCT, BZ1, GT1, and UGT79B1), isoflavonoid biosynthesis genes (HIDH and CYP81E17), and their transcriptional regulator (MYB). A total of 234 types of flavonoids were detected. The types and contents of anthocyanins in the red-leaf varieties 'Hong Jingling' and 'Caidie Fanfei' were significantly higher than those in the green leaf cultivar 'Lv Baoshi', especially morning glory 3-O-glucoside, delphinidin 3-O-glucoside, and pelargonium-3-O-glucoside, which were not detected in 'Lv Baoshi'. Combined omics analysis showed that downregulated expression of C4H, CHS and F3'5'H and upregulated expression of FLS reduced the supply of raw materials for anthocyanin synthesis, and downstream ANR upregulation converted anthocyanins to procyanidins, increasing the total flavonoid content. F3'5'H expression was downregulated in the leaves of each variety with development, resulting in the accumulation of catechins and the gradual greening of the leaves. F3'5'H was significantly depleted in the young leaves of 'Hong Jingling' and 'Caidie Fanfei' compared with the young leaves of 'Lv Baoshi', while ANS and BZ1 were enriched significantly. It is concluded that F3'5'H, BZ1, and ANS are the key genes needed for breeding red A. truncatum and that ANR is the key gene needed for breeding varieties with a high flavonoids contens. These results may facilitate genetic modification or selection for further improvement of the ornamental qualities and flavonoid content of A. truncatum.

Application of Circulating Tumor Cells and Circulating Free DNA from Peripheral Blood in the Prognosis of Advanced Gastric Cancer

Objective

To explore the application value of circulating tumor cells (CTCs) and circulating free DNA (cfDNA) from peripheral blood in the prognosis of advanced gastric cancer (AGC). Here, we measured CTCs and cfDNA quantity for predicting the outcome of patients. Patients and Methods. Forty-five patients with advanced gastric cancer who underwent neoadjuvant chemotherapy and surgical treatment were enrolled in this study. All patients received neoadjuvant chemotherapy with paclitaxel + S-1 + oxaliplatin (PSOX) regimen, and CTCs and cfDNA of the peripheral blood were detected before and after neoadjuvant therapy. Relationships between the number/type of CTC or cfDNA and the efficacy of neoadjuvant chemotherapy were analyzed.

Results

Among 45 patients, 43 (95.6%) were positive, and the positive rate of mesenchymal CTC was increased with the increase in the T stage. The proportion of mesenchymal CTC was positively correlated with the N stage (P < 0.05), and the larger N stage will have the higher proportion of mesenchymal CTC. Patients with a small number of mesenchymal CTC before neoadjuvant chemotherapy were more likely to achieve partial response (PR) with neoadjuvant therapy. Patients with positive CA-199 were more likely to achieve PR with neoadjuvant therapy (P < 0.05). Patients in the PR group were more likely to have decreased/unchanged cfDNA concentration after neoadjuvant therapy (P=0.119). After neoadjuvant therapy (before surgery), the cfDNA concentration was higher and the efficacy of neoadjuvant therapy (SD or PD) was lower (P=0.045).

Conclusions

Peripheral blood CTC, especially interstitial CTC and cfDNA, has a certain value in predicting the efficacy and prognosis of neoadjuvant chemotherapy in advanced gastric cancer.

Next-Generation Sequencing Analysis of Gastric Cancer Identifies the Leukemia Inhibitory Factor Receptor as a Driving Factor in Gastric Cancer Progression and as a Predictor of Poor Prognosis

Gastric cancer (GC) is the third cause of cancer-related mortality worldwide. Nevertheless, because GC screening programs are not cost-effective, most patients receive diagnosis in the advanced stages, when surgical options are limited. Peritoneal dissemination occurs in approximately one-third of patients with GC at the diagnosis and is a strong predictor of poor outcome. Despite the clinical relevance, biological and molecular mechanisms underlying the development of peritoneal metastasis in GC remain poorly defined. Here, we report results of a high-throughput sequencing of transcriptome expression in paired samples of non-neoplastic and neoplastic gastric samples from 31 patients with GC with or without peritoneal carcinomatosis. The RNA-seq analysis led to the discovery of a group of highly upregulated or downregulated genes, including the leukemia inhibitory factor receptor (LIFR) and one cut domain family member 2 (ONECUT2) that were differentially modulated in patients with peritoneal disease in comparison with patients without peritoneal involvement. Both LIFR and ONECUT2 predicted survival at univariate statistical analysis. LIFR and its major ligand LIF belong to the interleukin-6 (IL-6) cytokine family and have a central role in immune system regulation, carcinogenesis, and dissemination in several human cancers. To confirm the mechanistic role of the LIF/LIFR pathway in promoting GC progression, GC cell lines were challenged in vitro with LIF and a LIFR inhibitor. Among several GC cell lines, MKN45 cells displayed the higher expression of the receptor, and their exposure to LIF promotes a concentration-dependent proliferation and epithelial-mesenchymal transition (EMT), as shown by modulation of relative expression of E-cadherin/vimentin along with JAK and STAT3 phosphorylation and acquisition of a migratory phenotype. Furthermore, exposure to LIF promoted the adhesion of MKN45 cells to the peritoneum in an ex vivo assay. These effects were reversed by the pharmacological blockade of LIFR signaling. Together, these data suggest that LIFR might have a major role in promoting disease progression and peritoneal dissemination in patients with GC and that development of LIF/LIFR inhibitors might have a role in the treatment of GC.

Screening of Active Components and Key Targets of Radix Codonopsis in the Treatment of Gastric Cancer

Gastric cancer is the fifth most common cancer type in the world. The incidence and mortality of gastric cancer in China ranks second among malignant tumors in the country. At present, the main treatment method of gastric cancer is still surgical resection combined with chemotherapy. However, chemotherapy drugs will cause serious toxic and side effects on other normal tissues and cells. At the same time, chemotherapy drugs can make patients develop drug resistance and seriously affect the curative effect. By contrast, Chinese medicine has more advantages in the treatment of cancer. Dangshen (Radix Codonopsis), a traditional Chinese medicine, has been proved to be effective for the clinical treatment of gastric cancer. However, due to the complex components of Dangshen, the main active components and pharmacological mechanism for its treatment of gastric cancer are still unclear. In this study, the main active components and pharmacological mechanism of Radix Codonopsis in the treatment of gastric cancer were preliminarily explored based on network pharmacology and molecular docking. We obtained bioactive compounds and targets from Radix Codonopsis from the Chinese Medicine System Pharmacology Database (TCMSP) and constructed the active ingredient-target network of Codonopsis pilosula. We then obtained targets related to gastric cancer from the disease database. The common targets of Radix Codonopsis and gastric cancer were the key target of Radix Codonopsis for the treatment of gastric cancer. Then, we used Metascapedatabase to conduct functional enrichment analysis on the key targets of Radix Codonopsis for the treatment of gastric cancer to clarify the mechanism of Radix Codonopsis for the treatment of gastric cancer. We constructed a network to screen the main bioactive compounds and therapeutic targets, assessed the prognostic value of the main target genes by survival analysis, and finally assessed the binding affinity of the main target genes and main bioactive compounds of Radix Codonopsis for the treatment of gastric cancer by molecular docking. The results showed that the main active compounds of Codonopsis pilosula in treating gastric cancer were luteolin and cryptotanshinone, which played a role in the treatment of gastric cancer through the multitarget and multipathway mechanism.

Identification and epidemiological evaluation of gastric cancer risk factors: based on a field synopsis and meta-analysis in Chinese population

To summarize and assess the credibility and strength of non-genetic factors and genetic variation on gastric cancer risk, we performed a field synopsis and meta-analysis to identify the risk of gastric cancer in Chinese population. Cumulative evidence was graded according to the Venice criteria, and attributable risk percentage (ARP) and population attributable risk percentage (PARP) were used to evaluate the epidemiological effect. A total of 956 studies included non-genetic (404 studies) and genetic factors (552 studies) were quantified, and data on 1161 single nucleotide polymorphisms (SNPs) were available. We identified 14 non-genetic factors were significantly associated with gastric cancer risk. For the analysis of time trends, H. pylori infection rate in gastric cancer and population showed a downward trend. Meanwhile 22 variants were identified significantly associated with gastric cancer: 3 (PLCE1 rs2274223, PSCA rs2976392, MUC1 rs4072037) were high and 19 SNPs were intermediate level of summary evidence, respectively. For non-genetic factors, the top three for ARP were 54.75% (pickled food), 65.87% (stomach disease), and 49.75% (smoked and frying). For PARP were 34.22% (pickled food), 34.24% (edible hot food) and 23.66%(H. pylori infection). On the basis of ARP and PARP associated with SNPs of gastric cancer, the top three for ARP were 53.91% (NAT2, rs1799929),53.05% (NAT2 phenotype), and 42.85% (IL-10, rs1800896). For PARP (Chinese Han in Beijing) were 36.96% (VDR, rs731236), 25.58% (TGFBR2, rs3773651) and 20.56% (MUC1, rs4072037). Our study identified non-genetic risk factors and high-quality biomarkers of gastric cancer susceptibility and their contribution to gastric cancer.

Integrative omics analysis reveals effective stratification and potential prognosis markers of pan-gastrointestinal cancers

Gastrointestinal (GI) tract cancers are the most common malignant cancers with high mortality rate. Pan-cancer multi-omics data fusion provides a powerful strategy to examine commonalities and differences among various cancer types and benefits for the identification of pan-cancer drug targets. Herein, we conducted an integrative omics analysis on The Cancer Genome Atlas pan-GI samples including six carcinomas and stratified into 9 clusters, i.e. 5 single-type-dominant clusters and 4 mixed clusters, the clustering reveals the molecular features of different subtypes, other than the organ and cell-of-origin classifications. Especially the mixed clusters revealed the homogeneity of pan-GI cancers. We demonstrated that the prognosis differences among pan-GI subtypes based on multi-omics integration are more significant than clustering by single-omics. The potential prognostic markers for pan-GI stratification were identified by proportional hazards model, such as PSCA (for colorectal and stomach cancer) and PPP1CB (for liver and pancreatic cancer), which have prominent prognostic power supported by high concordance index.

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Pan-cancer multi-omics strategy reveals homogeneity and heterogeneity of pan-GI cancers

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Identify 9 iclusters with significantly different survival and molecular features

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Potential prognostic markers have prominent power supported by concordance index

Knockdown of Microtubule Associated Serine/threonine Kinase Like Expression Inhibits Gastric Cancer Cell Growth and Induces Apoptosis by Activation of ERK1/2 and Inactivation of NF-κB Signaling

Microtubule-associated serine/threonine kinase (MASTL) functions to regulate chromosome condensation and mitotic progression. Therefore, aberrant MASTL expression is commonly implicated in various human cancers. This study analyzed MASTL expression in gastric cancer vs. adjacent normal tissue for elucidating the association with clinicopathological data from patients. This work was then extended to investigate the effects of MASTL knockdown on tumor cells in vitro. The level of MASTL expression in gastric cancer tissue was assessed from the UALCAN, GEPIA, and Oncomine online databases. Lentivirus carrying MASTL or negative control shRNA was infected into gastric cancer cells. RT-qPCR, Western blotting, cell viability, cell counting, flow cytometric apoptosis and cell cycle, and colony formation assays were performed. MASTL was upregulated in gastric cancer tissue compared to the adjacent normal tissue, and the MASTL expression was associated with advanced tumor stage, Helicobacter pylori infection and histological subtypes. On the other hand, knockdown of MASTL expression significantly reduced tumor cell viability and proliferation, and arrested cell cycle at G₂/M stage but promoted tumor cells to undergo apoptosis. At protein level, knockdown of MASTL expression enhanced levels of cleaved PARP1, cleaved caspase-3, Bax and p-ERK1/2 expression, but downregulated expression levels of BCL-2 and p-NF-κB-p65 protein in AGS and MGC-803 cells. MASTL overexpression in gastric cancer tissue may be associated with gastric cancer development and progression, whereas knockdown of MASTL expression reduces tumor cell proliferation and induces apoptosis. Further study will evaluate MASTL as a potential target of gastric cancer therapeutic strategy.

Tumor-infiltrating B cell is associated with the control of progression of gastric cancer

This study aimed to further explore the clinicopathological correlation of B cell infiltration in gastric cancer (GC) and its impact on prognostic. By immunohistochemical method, CD20+ B cells, CD3+ T cells, CD66b+ tumor-associated neutrophils, CD163+ tumor-associated macrophages, and CD57+ natural killer cells were analyzed in consecutive sections of 584 GC tissues and 69 normal adjacent tissues. Kaplan-Meier and Cox regression analyses determined the relationship between clinical relevance or prognosis and B cell infiltration. The correlation between total B cell infiltration and various T cell subtype infiltration in GC tissues from 407 patients in the TCGA data was also analyzed. Kaplan-Meier and Cox regression analyses determined the effects of total B cell infiltration and various B cell subtype infiltration on the prognosis of patients with GC. The infiltration level of CD20+ B cells was positively correlated with that of T cells (risk ratio [RR] = 0.0930), especially CD4+ T cells and CD8+ T cells (P < 0.05). A high level of CD20+ B cell infiltration was significantly associated with low lymph node involvement and low TNM stage (P < 0.05). High levels of CD20+ B cell infiltration were significantly associated with improvements in overall survival and disease-free survival. Univariate Cox regression and multivariate Cox regression analysis showed that CD20+ B cell infiltration was an independent protective factor of prognosis. Higher levels of class-switched memory B cell and plasma cell also reflected better overall survival, and class-switched memory B cell and plasma cell were independent protective factors for prognosis. The findings indicate that B cell infiltration in GC, especially switched memory B cells and plasma cells, has a significant effect on tumor progression and prognosis.

Lesiones premalignas y malignas del estómago en pacientes sin tamización para cáncer gástrico

Introducción. Para establecer una frecuencia de seguimiento como método de tamización en cáncer gástrico, se propone la endoscopia en pacientes mayores de 35 años con síntomas de dispepsia, y en pacientes mayores de 40 años con alto riesgo. La demora en la realización de la primera endoscopia en la vida de un paciente incrementa el riesgo de no detectar lesiones premalignas ni cáncer potencialmente prevenible. Los objetivos de nuestro estudio fueron describir el número de pacientes mayores de 40 años con endoscopia de primera vez y evaluar la presencia de lesiones premalignas y malignas del estómago en pacientes sin tamización. Métodos. Revisión retrospectiva de base de datos. Se describieron hallazgos de informes de histopatología en pacientes mayores de 40 años (lesiones premalignas y malignas). Adicionalmente se describieron las variables sociodemográficas de los pacientes con endoscopia de primera vez y la presencia de infección por Helicobacter pylori en la población mencionada. Resultados. Setenta y ocho pacientes (23,6 %) tuvieron una endoscopia de primera vez siendo mayores de 40 años. En el 44 % de los pacientes se encontró la presencia de Helicobacter pylori, 25,4 % de los pacientes presentaron atrofia gástrica, 23,1 % metaplasia, ningún paciente presentó displasia y un paciente (1,3 %) presentó un adenocarcinoma gástrico. Discusión. Los resultados de nuestro estudio muestran un número elevado de pacientes sin endoscopia de tamización. Nuestro estudio resalta la importancia del uso de la endoscopia de tamización en la prevención, así como en el diagnóstico temprano de cáncer gástrico y sugiere mayor adherencia a las guías de práctica clínica.

Pathways of Gastric Carcinogenesis, Helicobacter pylori Virulence and Interactions with Antioxidant Systems, Vitamin C and Phytochemicals

Helicobacter pylori is a class one carcinogen which causes chronic atrophic gastritis, gastric intestinal metaplasia, dysplasia and adenocarcinoma. The mechanisms by which H. pylori interacts with other risk and protective factors, particularly vitamin C in gastric carcinogenesis are complex. Gastric carcinogenesis includes metabolic, environmental, epigenetic, genomic, infective, inflammatory and oncogenic pathways. The molecular classification of gastric cancer subtypes has revolutionized the understanding of gastric carcinogenesis. This includes the tumour microenvironment, germline mutations, and the role of Helicobacter pylori bacteria, Epstein Barr virus and epigenetics in somatic mutations. There is evidence that ascorbic acid, phytochemicals and endogenous antioxidant systems can modify the risk of gastric cancer. Gastric juice ascorbate levels depend on dietary intake of ascorbic acid but can also be decreased by H. pylori infection, H. pylori CagA secretion, tobacco smoking, achlorhydria and chronic atrophic gastritis. Ascorbic acid may be protective against gastric cancer by its antioxidant effect in gastric cytoprotection, regenerating active vitamin E and glutathione, inhibiting endogenous N-nitrosation, reducing toxic effects of ingested nitrosodimethylamines and heterocyclic amines, and preventing H. pylori infection. The effectiveness of such cytoprotection is related to H. pylori strain virulence, particularly CagA expression. The role of vitamin C in epigenetic reprogramming in gastric cancer is still evolving. Other factors in conjunction with vitamin C also play a role in gastric carcinogenesis. Eradication of H. pylori may lead to recovery of vitamin C secretion by gastric epithelium and enable regression of premalignant gastric lesions, thereby interrupting the Correa cascade of gastric carcinogenesis.

Clinicopathological Characteristics and Incidence of Gastric Cancer in Eastern India: A Retrospective Study

PURPOSE

To study the association of gastric cancer with various clinicopathological traits in eastern India which can be used as an important factor for further analysis, understanding of the diseases and amelioration of patients.

METHODS

The retrospective study includes the patients who underwent subtotal or total gastrectomy from surgical oncology department of Chittaranjan National Cancer Institute (hospital) of West Bengal, India between 2014 and 2018. The study includes 751 gastric cancer patients from Chittaranjan National Cancer Institute. We used electronic hospital records to collect data on various clinical parameters and other information. We used Microsoft Office Excel 2007 spreadsheets for the statistical analyses.

RESULTS

Incidence of gastric cancer is associated with mid age (40-59 years) group male patients and lymph node metastasis. Frequency of gastric cancer is highest in the antrum (42.21%). Of the mid age group gastric cancer patients, 35.02% were having much high risk of developing diffused type of adenocarcinoma (P < 0.00001). Tobacco intake in form of smoking was found as an important risk factor in gastric cancer development with risk ratio and odds ratio of 1.18 and 3.14 respectively.

CONCLUSION

Collectively, the results of the present study confirm that incidence of diffused type of gastric cancer is increasing as an alarming rate in mid age group male patients and tobacco intake in the form of smoking as an independent risk factor for this type of cancer in eastern India. This result can be used to manage gastric carcinoma in future prospective clinical studies and in patient's improvement.

Preparation, characterization, and anticancer efficacy of novel cobalt oxide nanoparticles conjugated with thiosemicarbazide

Gastric cancer is one of the most common cancers in modern societies. Previous studies have shown that the use of nanoparticle complexes is effective in the treatment of cancer. The aim of this study was to investigate the cytotoxicity and anticancer properties of cobalt oxide (Co₃O₄) nanoparticles (NPs) functionalized by glutamic acid (Glu) and conjugated with thiosemicarbazide (TSC) on gastric cancer (AGS) cell line. First, the Co₃O₄@Glu/TSC nanoparticles were synthesized via co-condensation reaction. Fourier-transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) tests were performed for identifying the morphology, structure, size and functional groups of produced nanoparticles. MTT assay was also performed to evaluate cytotoxicity effect. Moreover, Annexin V/PI staining with flow cytometry analysis, caspase-3 activation assay, and Hoechst 33258 staining was carried out for evaluating apoptosis. The FTIR results showed that the components of Co₃O₄@Glu/TSC NPs complex were successfully fabricated. Crystallographic structure of Co₃O₄@Glu/TSC NPs was confirmed by XRD patterns. SEM results indicated that the size of the nanoparticles was in the range of 16-40 nm. An EDX spectrum was determined and data explained the existence of cobalt as the prominent element. MTT test results showed that AGS cell life was significantly decreased compared to the control group with increasing concentration of nanoparticles (dose-dependent) (P < 0.05), IC₅₀ = 107.5 μg/mL. The results of flow cytometry assay and caspase-3 activity showed that fabricated Co₃O₄@Glu/TSC NPs induced apoptosis in the treated group. Moreover, Co₃O₄@Glu/TSC NPs treated AGS cells indicate an increase in the apoptotic characteristics including nuclear fragmentation. In the current work, the promising cytotoxicity and anti-cancer activities of Co₃O₄@Glu/TSC NPs complex toward gastric cancer (AGS) cell line were showed and it can be suggested for the drug delivery system.

Polo-like kinase 1 as a promising diagnostic biomarker and potential therapeutic target for hepatocellular carcinoma

Hepatocellular carcinoma is a major cause of cancer mortality worldwide. The outcome of hepatocellular carcinoma depends mainly on its early diagnosis. To date, the performance of traditional biomarkers is unsatisfactory. Polo-like kinase 1 is a serine/threonine kinase that plays essential roles in cell cycle progression and deoxyribonucleic acid damage. Moreover, polo-like kinase 1 knockdown decreases the survival of hepatocellular carcinoma cells; therefore, polo-like kinase 1 is an attractive target for anticancer treatments. Nobiletin, a natural polymethoxy flavonoid, exhibits a potential antiproliferative effect against a wide variety of cancers. This study targets to identify a reliable diagnostic biomarker for hepatocellular carcinoma and provide a potential therapeutic target for its treatment. Polo-like kinase 1 levels were analyzed in 44 hepatocellular carcinoma patients, 33 non-hepatocellular carcinoma liver cirrhosis patients and 15 healthy controls using the enzyme-linked immunosorbent assay method. Receiver operating characteristics curve analysis was used to establish a predictive model for polo-like kinase 1 relative to α-fetoprotein in hepatocellular carcinoma diagnosis. Furthermore, in the in vitro study, gene expressions were assessed by quantitative polymerase chain reaction in two human hepatocellular carcinoma cell lines after treatment with doxorubicin and polo-like kinase 1 inhibitor volasertib (Vola) either alone or in combination with nobiletin. Cell viability was also determined using the crystal violet assay.: Serum polo-like kinase 1 levels in hepatocellular carcinoma patients were significantly higher than liver cirrhosis and control groups (p < 0.0001). Polo-like kinase 1 showed a reasonable sensitivity, specificity, positive predictive value, and negative predictive value in hepatocellular carcinoma diagnosis. Moreover, nobiletin improved inhibition of cell growth induced by Vola and doxorubicin. Regarding reverse transcription polymerase chain reaction results, nobiletin suppressed expressions of polo-like kinase 1 and proliferating cell nuclear antigen and elevated expressions of P53, poly (ADPribose) polymerase 1, and caspase-3. Nobiletin/doxorubicin and nobiletin/Vola showed a significant increase in caspase-3 activity indicating cell apoptosis. Polo-like kinase 1 may be a potential biomarker for hepatocellular carcinoma diagnosis and follow-up during treatment with chemotherapies. In addition, nobiletin synergistically potentiates the doxorubicin and Vola-mediated anticancer effect that may be attributed partly to suppression of polo-like kinase 1 and proliferating cell nuclear antigen expression and enhancement of chemotherapy-induced apoptosis.

Risk factors for stomach cancer: a systematic review and meta-analysis

OBJECTIVES

This report provides information on 14 behavioral and nutritional factors that can be addressed in stomach cancer prevention programs.

METHODS

PubMed, Web of Science, and Scopus were searched through December 2018. Reference lists were also screened. Observational studies addressing the associations between stomach cancer and behavioral factors were analyzed. Between-study heterogeneity was investigated using the χ2, τ2, and I2 statistics. The likelihood of publication bias was explored using the Begg and Egger tests and trim-and-fill analysis. Effect sizes were expressed as odds ratios (ORs) with 95% confidence intervals (CIs) using a random-effects model.

RESULTS

Of 52,916 identified studies, 232 (including 33,831,063 participants) were eligible. The OR (95% CI) of factors associated with stomach cancer were as follows: Helicobacter pylori infection, 2.56 (95% CI, 2.18 to 3.00); current smoking, 1.61 (95% CI, 1.49 to 1.75); former smoking 1.43 (95% CI, 1.29 to 1.59); current drinking, 1.19 (95% CI, 1.10 to 1.29); former drinking, 1.73 (95% CI, 1.17 to 2.56); overweight/obesity, 0.89 (95% CI, 0.74 to 1.08); sufficient physical activity, 0.83 (95% CI, 0.68 to 1.02); consumption of fruits ≥3 times/wk, 0.48 (95% CI, 0.37 to 0.63); consumption of vegetables ≥3 times/wk, 0.62 (95% CI, 0.49 to 0.79); eating pickled vegetables, 1.28 (95% CI, 1.09 to 1.51); drinking black tea, 1.00 (95% CI, 0.84 to 1.20); drinking green tea, 0.88 (95% CI, 0.80 to 0.97); drinking coffee, 0.99 (95% CI, 0.88 to 1.11); eating fish ≥1 time/wk 0.79 (95% CI, 0.61 to 1.03); eating red meat ≥4 times/wk 1.31 (95% CI, 0.87 to 1.96), and high salt intake 3.78 (95% CI, 1.74 to 5.44) and 1.34 (95% CI, 0.88 to 2.03), based on two different studies.

CONCLUSIONS

This meta-analysis provided a clear picture of the behavioral and nutritional factors associated with the development of stomach cancer. These results may be utilized for ranking and prioritizing preventable risk factors to implement effective prevention programs.

Knockdown Of CCDC132 Attenuates Gastric Cancer Cells Proliferation And Tumorigenesis By Facilitating DNA Damage Signaling

Background

Aberrant endocytic recycling has fundamental functions on plasma membrane component turnover. Recent studies have identified an uncharacterized protein, CCDC132, in the endosome-associated recycling protein complex. Besides, our preliminary data first showed that CCDC132 was elevated in malignant neoplasms, especially in esophagus/stomach cancers. However, the functions and the underlying mechanisms of CCDC132 in gastric cancer (GC) biology remain unclear.

Methods

The CCDC132 mRNA expression in 4 GC cell lines and normal gastric epithelial cell lines was detected by qRT-PCR. Then, CCDC132 was downregulated in AGS and MGC-803 cells by lentivirus-induced RNA interfere, and cell viability assay, clone formation assay and apoptosis assay were carried out. The mechanism of CCDC132 on cell proliferation and apoptosis activation was explored using PathScan^® Stress, apoptosis signaling arrays and Western blot. We further investigated the pro-oncogenesis of CCDC132 in vivo. Meanwhile, immunohistochemistry was utilized to analyze the association between CCDC132 expression and clinicopathological features and prognosis. Finally, the correlation between CCDC132 and p53 was analyzed by Spearman’s rank correlation analysis.

Results

In this study, knockdown of CCDC132 significantly decreased cell proliferation and clone formation ability and facilitated apoptosis, and increased phosphorylation of p53 and Chk2 and protein levels of γ-H2AX, 53BP1, cleaved Caspase 3 and cleaved PARP. Additionally, knockdown of CCDC132 attenuated tumorigenesis and tumor growth of MGC-803 cell xenografts. CCDC132 expression was significantly higher in GC tissues compared with that in adjacent normal tissues and was positively correlated with nodal metastasis and TNM stage and negatively associated with prognosis. The survival rate of CCDC132 positive patients was lower than that of CCDC132-negative patients. Furthermore, CCDC132 expression was negatively related to p53.

Conclusion

This study unravels that knockdown of CCDC132 attenuates GC cell proliferation and tumorigenesis by facilitating DNA damage signaling, indicating that CCDC132 may serve as a potential target for GC therapy.

The Role of PGC-1α in Digestive System Malignant Tumours

BACKGROUND

Cancer is increasingly becoming the leading cause of death in many countries, and malignant tumours of the digestive system account for majority of cancer incidence and mortality cases. Metabolism has been identified as a core hallmark of cancer. Peroxisome proliferator activated receptor gamma coactivator-1 alpha (PGC-1α) is a pivotal regulator of mitochondrial energy metabolism. Accumulating evidence reveals that PGC-1α is essential in cancer development.

OBJECTIVE

We summarize the latest research progress of PGC-1α in common digestive system malignant tumours. Some related modulators and pathways are analyzed as well.

METHODS

We conducted a literature review on the development of PGC-1α in common digestive system malignant tumours.

RESULTS

In colorectal cancer, PGC-1α appears to provide growth advantages by different pathways, although it has also been reported to have opposite effects. The previous studies of PGC-1α on liver cancer also demonstrated different effects by sundry pathways. Concerning gastric cancer, PGC-1α promotes cell proliferation, apoptosis in vitro and tumour growth in vivo. AMPK/SIRT1/PGC-1α is related to the inhibition of apoptosis in pancreatic cancer cells. Pancreatic cancer stem cells are strongly dependent on mitochondrial oxidative phosphorylation. PGC-1α is required to maintain the stemness property of pancreatic cancer stem cells.

CONCLUSION

We explore diverse mechanisms that explain the dichotomous functions of PGC-1α on tumorigenesis, and discuss the latest research concerning digestive system malignant tumours. This review would provide better comprehension of the field and a basis for further studies associated with PGC-1α in digestive system cancers.

MiR-876-3p regulates cisplatin resistance and stem cell-like properties of gastric cancer cells by targeting TMED3

BACKGROUND AND AIM

Gastric cancer (GC), a prevalent tumor, exerts a major economic burden, and we aimed to explore miR-876-3p's effects on GC and related mechanisms.

METHODS

Cell viability was analyzed via CCK-8 and colony formation assay. Stem cell-like properties were examined via spheroid colony formation assay. mRNA abundance of key genes was analyzed via quantitative polymerase chain reaction. Protein level of TMED3 and stem cell markers was examined by western blot. TargetScan, luciferase, and biotin-miRNA pulldown assay were used to identify miR-876-3p's target.

RESULTS

MiR-876-3p was downregulated in GC, and its mRNA level had negative relationship with cisplatin resistance of GC. Moreover, decreased miR-876-3p expression level suggested poor prognosis of GC patients. MiR-876-3p inhibited drug resistance of cisplatin-resistant cell line SGC-7901/DDP and MKN-45/DDP, as shown by decreased cell viability, IC₅₀ , and colony formation ability. MiR-876-3p inhibited stem cell-like features and downregulated the expressions of Sox-2, Oct-4, CD133, and CD44 in GC cells. Luciferase and biotin-miRNA pulldown assay confirmed that TMED3 was miR-876-3p's direct target. TMED3 siRNA inhibited miR-876-3p's effects on cisplatin resistance and stem cell-like features of SGC-7901/DDP cells.

CONCLUSION

MiR-876-3p enhanced cisplatin sensitivity and restricted stem cell-like features of GC through targeting TMED3.

Preclinical evaluation of exemestane as a novel chemotherapy for gastric cancer

CYP19A1/aromatase (Ar) is a prognostic biomarker of gastric cancer (GCa). Ar is a critical enzyme for converting androstenedione to oestradiol in the steroidogenesis cascade. For decades, Ar has been targeted with Ar inhibitors (ARIs) in gynaecologic malignancies; however, it is unexplored in GCa. A single‐cohort tissue microarray examination was conducted to study the association between Ar expression and disease outcome in Asian patients with GCa. The results revealed that Ar was a prognostic promoter. Bioinformatics analyses conducted on a Caucasian‐based cDNA microarray databank showed Ar to be positively associated with GCa prognosis for multiple clinical modalities, including surgery, 5‐Fluorouracil (5‐FU) for adjuvant chemotherapy, or HER2 positivity. These findings imply that targeting Ar expression exhibits a potential for fulfilling unmet medical needs. Hence, Ar‐targeting compounds were tested, and the results showed that exemestane exhibited superior cancer‐suppressing efficacy to other ARIs. In addition, exemestane down‐regulated Ar expression. Ablating Ar abundance with short hairpin (sh)Ar could also suppress GCa cell growth, and adding 5‐FU could facilitate this effect. Notably, adding oestradiol could not prevent exemestane or shAr effects, implicating a nonenzymatic mechanism of Ar in cancer growth. Regarding translational research, treatment with exemestane alone exhibited tumour suppression efficacy in a dose‐dependent manner. Combining subminimal doses of 5‐FU and exemestane exerted an excellent tumour suppression effect without influencing bodyweight. This study validated the therapeutic potentials of exemestane in GCa. Combination of metronomic 5‐FU and exemestane for GCa therapy is recommended.

LncRNA LOXL1-AS1 facilitates the tumorigenesis and stemness of gastric carcinoma via regulation of miR-708-5p/USF1 pathway

Objectives

As one of the most life‐threatening malignancies, gastric cancer is the third contributor of cancer mortalities globally. Increasing studies have proven the regulatory roles of lncRNAs in the development of diverse malignant tumours. But little is known about its function and molecular mechanism in gastric carcinoma.

Materials and methods

RT‐qPCR was performed to measure the expression pattern of LOXL1‐AS1 in gastric cancer. To ascertain its definite role, CCK‐8, EdU, Western blot, transwell and sphere formation assays were adopted. RNA pull‐down, RIP, ChIP and luciferase reporter assays were carried out to investigate the molecular mechanism of LOXL1‐AS1 in gastric carcinoma.

Results

LOXL1‐AS1 was highly expressed in tissues and cells of gastric cancer. The upregulation of LOXL1‐AS1 predicted poor prognosis in gastric carcinoma. Our findings demonstrated that LOXL1‐AS1 accelerated the deterioration of gastric cancer by inducing cell proliferation, migration, EMT and stemness. Moreover, the expression of USF1 in gastric cancer was higher than in normal control and LOXL1‐AS1 negatively modulated USF1. Functionally, LOXL1‐AS1 acted as a ceRNA to upregulate USF1 via sponging miR‐708‐5p. Besides, we confirmed USF1 promoted the transcription of stemness marker SOX2. Rescue experiments testified the stimulative role of LOXL1‐AS1/miR‐708‐5p/USF1 pathway in gastric cancer progression. It was also validated that LOXL1‐AS1 facilitated cell growth of gastric carcinoma in vivo.

Conclusions

Our study unravelled that LOXL1‐AS1/miR‐708‐5p/USF1 pathway contributed to the development of gastric cancer.

rs12416605:C>T in MIR938 associates with gastric cancer through affecting the regulation of the CXCL12 chemokine gene

Background

MicroRNAs are small regulatory RNAs with important roles in carcinogenesis. Genetic variants in these regulatory molecules may contribute to disease. We aim to identify allelic variants in microRNAs as susceptibility factors to gastric cancer using association studies and functional approaches.

Methods

Twenty‐one single nucleotide variants potentially functional, because of their location in either the seed, mature or precursor region of 22 microRNAs, were selected for association studies. Genetic association with gastric cancer in 365 cases and 1,284 matched controls (European Prospective Investigation into Cancer and Nutrition Cohort) was analysed using logistic regression. MicroRNA overexpression, transcriptome analysis, and target gene validation experiments were performed for functional studies.

Results

rs3746444:T>C, in the seed of MIR499A and mature MIR499B, associated with the cardia adenocarcinoma location; rs12416605:C>T, in the seed of MIR938, associated with the diffuse subtype; and rs2114358:T>C, in the precursor MIR1206, associated with the noncardia phenotype. In all cases, the association was inverse, indicating a protective affect against gastric cancer of the three minor allelic variants. MIR499 rs3746444:T>C and MIR1206 rs2114358:T>C are reported to affect the expression of these miRNAs, but the effect of MIR938 rs12416605:C>T is unknown yet. Functional approaches showed that the expression of MIR938 is affected by rs12416605:C>T and revealed that MIR938 could regulate a subset of cancer‐related genes in an allele‐specific fashion. Furthermore, we demonstrated that CXCL12, a chemokine participating in gastric cancer metastasis, is specifically regulated by only one of the rs12416605:C>T alleles.

Conclusion

rs12416605 appears to be involved in gastric cancer by affecting the regulatory function of MIR938 on genes related to this cancer type, particularly on CXCL12 posttranscriptional regulation.

Comparison and applicability of molecular classifications for gastric cancer

Gastric Cancer (GC) is a complex and heterogeneous disease, which represents a global health concern. Despite advances in prevention, diagnosis, and therapy, GC is still a leading cause of cancer-related death. Over the last decade, several clinical trials have tested novel agents for advanced GC with mostly disappointing results. Heterogeneity, the absence of molecular selection in clinical trials and powerless predictive biomarkers may be potential explanations. Different molecular classification proposals for GC based on the genetic, epigenetic, and molecular signatures have been published. Molecular characterization of GC may offer new tools for more effective therapeutic strategies, such as the development of therapies for specifically well-defined sets of patients as well as the use of new clinical trial designs, which will ultimately lead to an improvement of medical management of this disease. However, the possibilities of implementation of GC molecular classifications on daily practice and their therapeutic implications remain challenging to date. In this review, we will describe and compare these GC molecular classifications, focusing on their main characteristics as the basis for their potential therapeutic implications and strategies for their clinical application. Key Message: A better understanding of gastric cancer molecular characteristics may lead to further improvements in treatment and outcomes for patients with the disease.

Gastric Cancer in Northern Canadian Populations: A Focus on Cardia and Non-Cardia Subsites

In northern Canada where there is a high prevalence of Helicobacter pylori infection, there is a paucity of information on gastric cancer by the topographical subsites cardia (CGC) and non-cardia (NCGC). Here we describe the incidence of CGC and NCGC, separately, among northern Canadian populations. We used data from the Cancer Incidence in Five Continents Volumes X (CI5X) and XI (CI5XI) to obtain CGC and NCGC incidence for Canada and for Yukon (YT), a northern Canadian territory. Using these data with those provided by the Government of the Northwest Territories (NT), we estimated standardized incidence ratios comparing northern populations to Canada as a whole. We also estimated age-standardized incidence rates to permit comparisons across populations globally. NT and YT populations were disproportionately impacted by gastric cancer, particularly NCGC. This was especially true for Indigenous populations: NCGC incidence rates among NT Indigenous men were 2.7 times the rates among all men in Canada, while rates among NT Indigenous women were 3.1 times the rates among all women in Canada. Similarly, age-standardized rates of NCGC among Indigenous NT residents were comparable to global regions where there is a high burden of NCGC. This study has, for the first time, quantified the incidence of CGC and NCGC for the NT and YT, providing new insights into the burden of these cancers among northern Canadian populations.

Association study between genetic polymorphisms in folate metabolism and gastric cancer susceptibility in Chinese Han population: A case-control study

Background

Gastric cancer (GC), the second leading cause of cancer mortality behind lung cancer worldwide, is caused by both genetic and environmental factors. In this study, we evaluated the association between the genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR), methionine synthesis reductase (MTR), and methyltransferase reductase (MTRR) genes and ischemic stroke risk in Chinese population.

Methods

A case–control study was conducted including 681 patients with GC and 756 healthy controls. Chi‐squared test/Fisher's exact test and genetic model were used to evaluate associations. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression.

Results

In the allele model, using the chi‐square test, we found that the rs1532268 in MTRR with a minor allele T was significantly associated with increased risk of GC (OR = 1.24, 95% CI, 1.00–1.53; p = 0.048). In the genetic model analysis, we identified that the single‐nucleotide polymorphism of the rs1801133 in MTHFR could increase the GC risk in the recessive model (OR = 1.31, 95% CI, 1.01–1.70; p = 0.042) and log‐additive model (OR = 1.19, 95% CI, 1.02–1.38; p = 0.025). In MTHFR, a strong linkage of rs2274976 and rs1801133 was detected. The haplotype “GC” in the MTHFR gene was found to prominently increase the risk of GC (OR = 1.26, 95% CI: 1.07–1.47; p = 0.005). Other haplotypes did not display the correlativity.

Conclusion

This study suggested that MTR and MTHFR polymorphisms may contribute to increase the risk of GC.

Five-long non-coding RNA risk score system for the effective prediction of gastric cancer patient survival

The prognosis for patients with gastric cancer (GC) is usually poor, as the majority of patients have reached the advanced stages of disease at the point of diagnosis. Therefore, revealing the mechanisms of GC is necessary for the identification of key biomarkers and the development of effective targeted therapies. The present study aimed to identify long non-coding RNAs (lncRNAs) prominently expressed in patients with GC. The GC dataset (including 384 GC samples) was downloaded from The Cancer Genome Atlas database as the training set. A number of other GC datasets were obtained from the Gene Expression Omnibus database as validation sets. Following data processing, lncRNAs were annotated, followed by co-expression module analysis to identify stable modules, using the weighted gene co-expression network analysis (WGCNA) package. Prognosis-associated lncRNAs were screened using the ‘survival’ package. Following the selection of the optimal lncRNA combinations using the ‘penalized’ package, risk score systems were constructed and assessed. Consensus differentially-expressed RNAs (DE-RNAs) were screened using the MetaDE package, and an lncRNA-mRNA network was constructed. Additionally, pathway enrichment analysis was conducted for the network nodes using gene set enrichment analysis (GSEA). A total of seven modules (blue, brown, green, grey, red, turquoise and yellow) were obtained following WGCNA analysis, among which the green and turquoise modules were stable and associated with the histological grade of GC. A total of 12 prognosis-associated lncRNAs were identified in the two modules. Combined with the optimal lncRNA combinations, risk score systems were constructed. The risk score system based on the green module [including ITPK1 antisense RNA 1 (ITPK1-AS1), KCNQ1 downstream neighbor (KCNQ1DN), long intergenic non-protein coding RNA 167 (LINC00167), LINC00173 and LINC00307] was the more efficient at predicting risk compared with those based on the turquoise, or the green + turquoise modules. A total of 1,105 consensus DE-RNAs were identified; GSEA revealed that LINC00167, LINC00173 and LINC00307 had the same association directions with 4 pathways and the 32 genes involved in those pathways. In conclusion, a risk score system based on the green module may be applied to predict the survival of patients with GC. Furthermore, ITPK1-AS1, KCNQ1DN, LINC00167, LINC00173 and LINC00307 may serve as biomarkers for GC pathogenesis.

Bioinformatics analysis to identify action targets in NCI-N87 gastric cancer cells exposed to quercetin

CONTEXT

Quercetin exerts antiproliferative effects on gastric cancer. However, its mechanisms of action on gastric cancer have not been comprehensively revealed.

OBJECTIVE

We investigated the mechanisms of action of quercetin against gastric cancer cells.

MATERIALS AND METHODS

Human NCI-N87 gastric cancer cells were treated with 15 μM quercetin or dimethyl sulfoxide (as a control) for 48 h. DNA isolated from cells was sequenced on a HiSeq 2500, and the data were used to identify differentially expressed genes (DEGs) between groups. Then, enrichment analyses were performed for DEGs and a protein-protein interaction (PPI) network was constructed. Finally, the transcription factors (TFs)-DEGs regulatory network was visualized by Cytoscape software.

RESULTS

A total of 121 DEGs were identified in the quercetin group. In the PPI network, Fos proto-oncogene (FOS, degree = 12), aryl hydrocarbon receptor (AHR, degree = 12), Jun proto-oncogene (JUN, degree = 11), and cytochrome P450 family 1 subfamily A member 1 (CYP1A1, degree = 11) with higher degrees highly interconnected with other proteins. Of the 5 TF-DEGs, early growth response 1 (EGR1), FOS like 1 (FOSL1), FOS, and JUN were upregulated, while AHR was downregulated. Moreover, FOSL1, JUN, and Wnt family member 7B (WNT7B) were enriched in the Wnt signaling pathway.

DISCUSSION AND CONCLUSIONS

CYP1A1 highly interconnected with AHR in the PPI network. Therefore, FOS, AHR, JUN, CYP1A1, EGR1, FOSL1, and WNT7B might be targets of quercetin in gastric cancer.

Gankyrin Drives Malignant Transformation of Gastric Cancer and Alleviates Oxidative Stress via mTORC1 Activation

Gastric cancer, as a malignant epithelial tumor, is a major health threat leading to poor overall survival and death. It is usually diagnosed at an advanced stage due to asymptomatic or only nonspecific early symptoms. The present study demonstrated that gankyrin contributes to the early malignant transformation of gastric cancer and can be selected to predict the risk of gastric cancer in those patients harboring the precancerous lesions (dysplasia and intestinal metaplasia). In addition, a new insight into gastric cancer was provided, which stated that gankyrin alleviates oxidative stress via mTORC1 pathway activation. It can potentiate the mTORC1 by PGK1-AKT signaling that promotes the tumor process, and this phenomenon is not completely consistent with the previous report describing colorectal cancer.

The Association Between Metabolic Syndrome and Gastric Cancer in Chinese

Background: Metabolic syndrome (MetS) play a carcinogenic role in variety of cancers and influence the prognosis of cancer patients both systemically and hormonally. Methods: The data of clinicopathologic features and MetS of 808 gastric cancer patients and 1,146 randomly healthy controls were analyzed retrospectively. Results: Higher TG level, lower HDL-C level and higher hypertension frequency were observed in all gastric cancer patients when compared with healthy controls. While, gastric cancer patients had greater waist circumference only in females. Among three definitions of MetS, the MetS identified by the Chinese Diabetes Society (CDS) was associated with the most significant increasing risk of gastric cancer. Comparing all gastric cancer patients with healthy controls, OR of gastric cancer was enhanced by various individual components of the MetS, including higher TG level, lower HDL-C level, hypertension and diabetes; In male subgroup, OR of gastric cancer was enhanced by higher BMI, hypertension and diabetes; In females, OR of gastric cancer was enhanced by lower HDL-C, hypertension and diabetes. MetS was associated with poor differentiated carcinoma, more advanced pathological T, N stage and TNM stage of gastric cancer. Conclusion: The presence of MetS and its components were increased in gastric cancer, especially in gastric cancer patients with poor differentiation and advanced stage, which implies that metabolic disorder may play an important role in the development of gastric cancer.

Association of five genetic variations in DNMT1 and DNMT3A with gastric cancer in a Chinese population

AIM

To determine whether genetic variations in DNMT1 and DNMT3A could be associated with gastric cancer risk.

MATERIALS & METHODS

A total of 466 patients and 452 healthy controls were enrolled in this study. Genotypes were examined by using the Sequenom MassARRAY platform.

RESULTS

No significant differences in the distribution frequencies were observed between the groups. However, subgroup analysis revealed that, in the group aged ≤60 years, DNMT3A rs13420827 was associated with reduced gastric cancer risk, and that carrier of GC/GG genotype was associated with reduced risk of gastric cancer with low differentiation or at the T3-T4 stage.

CONCLUSION

This study suggests that five genetic variations of interest in DNMT1 and DNMT3A are not associated with the presence of gastric cancer, but that rs13420827 may contribute to the gastric cancer risk for those younger individuals, the risk of which may be influenced by the characteristics of tumor.

Citrus aurantium Naringenin Prevents Osteosarcoma Progression and Recurrence in the Patients Who Underwent Osteosarcoma Surgery by Improving Antioxidant Capability

Citrus aurantium is rich in flavonoids, which may prevent osteosarcoma progression, but its related molecular mechanism remains unclear. Flavonoids were extracted from C. aurantium and purified by reparative HPLC. Each fraction was identified by using electrospray ionisation mass spectrometry (ESI-MS). Three main components (naringin, naringenin, and hesperetin) were isolated from C. aurantium. Naringenin inhibited the growth of MG-63 cells, whereas naringin and hesperetin had no inhibitory function on cell growth. ROS production was increased in naringin- and hesperetin-treated groups after one day of culture while the level was always lowest in the naringenin-treated group after three days of culture. 95 osteosarcoma patients who underwent surgery were assigned into two groups: naringenin group (NG, received 20 mg naringenin daily, n = 47) and control group (CG, received 20 mg placebo daily, n = 48). After an average of two-year follow-up, osteosarcoma volumes were smaller in the NG group than in the CG group (P > 0.01). The rate of osteosarcoma recurrence was also lower in the NG group than in CG group. ROS levels were lower in the NG group than in the CG group. Thus, naringenin from Citrus aurantium inhibits osteosarcoma progression and local recurrence in the patients who underwent osteosarcoma surgery by improving antioxidant capability.

TRPM2 channel-mediated regulation of autophagy maintains mitochondrial function and promotes gastric cancer cell survival via the JNK-signaling pathway

A lack of effective treatment is one of the main factors contributing to gastric cancer-related death. Discovering effective targets and understanding their underlying anti-cancer mechanism are key to achieving the best response to treatment and to limiting side effects. Although recent studies have shown that the cation channel transient receptor potential melastatin-2 (TRPM2) is crucial for cancer cell survival, the exact mechanism remains unclear, limiting its therapeutic potential. Here, using molecular and functional assays, we investigated the role of TRPM2 in survival of gastric cancer cells. Our results indicated that TRPM2 knockdown in AGS and MKN-45 cells decreases cell proliferation and enhances apoptosis. We also observed that the TRPM2 knockdown impairs mitochondrial metabolism, indicated by a decrease in basal and maximal mitochondrial oxygen consumption rates and ATP production. These mitochondrial defects coincided with a decrease in autophagy and mitophagy, indicated by reduced levels of autophagy- and mitophagy-associated proteins (i.e. ATGs, LC3A/B II, and BNIP3). Moreover, we found that TRPM2 modulates autophagy through a c-Jun N-terminal kinase (JNK)-dependent and mechanistic target of rapamycin-independent pathway. We conclude that in the absence of TRPM2, down-regulation of the JNK-signaling pathway impairs autophagy, ultimately causing the accumulation of damaged mitochondria and death of gastric cancer cells. Of note, by inhibiting cell proliferation and promoting apoptosis, the TRPM2 down-regulation enhanced the efficacy of paclitaxel and doxorubicin in gastric cancer cells. Collectively, we provide compelling evidence that TRPM2 inhibition may benefit therapeutic approaches for managing gastric cancer.

Validation of Alcohol Flushing Questionnaires in Determining Inactive Aldehyde Dehydrogenase-2 and Its Clinical Implication in Alcohol-Related Diseases

BACKGROUND

Our aim was to validate alcohol flushing questionnaires in detecting inactive ALDH2 (ALDH2*1/*2 or ALDH2*2/*2).

METHODS

Two study sets were established; in study set 1, 210 healthy male subjects (age 22 to 59 years) were enrolled; in study set 2, 756 subjects were enrolled who received esophagogastroduodenoscopy to evaluate their dyspeptic symptoms or as part of a gastric cancer screening program. Subjects in study sets 1 and 2 completed the modified alcohol flushing questionnaires of Yokoyama and colleagues (, ). Polymerase chain reaction-restriction fragment length polymorphism method was used to determine ALDH2 genotype.

RESULTS

In study set 1, 29.0% (61 of 210) had inactive ALDH2. The sensitivity and specificity of the modified alcohol flushing questionnaire for detecting inactive ALDH2 were 95.1 and 76.5%, respectively. Drinking problems negatively correlated with positive alcohol flushing response and inactive ALDH2 (all p-values < 0.05). In study set 2, the sensitivity and specificity of the alcohol flushing questionnaire for detecting inactive ALDH2 were 78.9 and 82.1%, respectively. Interestingly, drinking ≥7 units/wk in men or ≥3.5 units/wk in women significantly increased the risk of benign gastric ulcer (BGU) among positive alcohol flushers (odds ratio, 8.97; 95% confidence interval, 1.38 to 58.30), but not among negative alcohol flushers.

CONCLUSIONS

Simple flushing questionnaires may be administered to the Korean population as a screening tool in detecting individuals who carry inactive ALDH2. Alcohol flushing response negatively correlates with drinking problems and can modify the risk for BGU by alcohol intake.

Nonsyndromic cleft lip and palate, gastric cancer and tooth agenesis

Background

To determine the frequency of nonsyndromic cleft lip and/or palate (NSCL/P) in first-degree relatives and to analyze the prevalence of tooth agenesis in patients with gastric cancer.

Material and Methods

This cross-sectional, observational, case-control study included 798 patients attended at hospital Santa Casa in Montes Claros, Minas Gerais and Alfa Institute of Gastroenterology of the Federal University of the Minas Gerais. Information on basic demographic data and tooth agenesis of both groups and their family history of NSCL/P in first-degree relatives were evaluated. The collected information was stored in a database and analyzed using statistical program SPSS® version 21.0 and the values with p<0.05 were considered statistically significant.

Results

Of the 798 patients, 113 (14.16%) consisted of the case group and 685 of the control group (85.84%). Non-Caucasian males were the most affected, although no differences among the groups were detected. Of all participants (n=798), 66 (8.27%) presented tooth agenesis and 25 (3.13%) presented oral cleft in first degree relative.

Conclusions

Our results no found increase in the frequency of tooth agenesis in patients with gastric cancer and in the frequency of NSCL/P in the first-degree relatives of patients with gastric cancer.

Key words:Nonsyndromic cleft lip and/or palate, tooth agenesis, gastric cancer.

Prior gastroscopy and mortality in patients with gastric cancer: a matched retrospective cohort study

BACKGROUND AND AIMS

The role of prior gastroscopy on the outcome of patients with gastric cancer remains unknown. This study determines the association between intervals of prior gastroscopy and mortality in patients with gastric cancer.

METHODS

We identified 20,066 newly diagnosed patients with gastric cancer in the National Health Insurance Database of Taiwan between 2002 and 2007. After we excluded patients who had gastroscopies performed ≤6 months before the diagnosis of cancer, patients were matched into 3 cohorts according to the intervals of prior gastroscopy: 6 months to 2 years (<2 Y cohort), 2 to 5 years (2-5 Y cohort), and none within the previous 5 years (>5 Y cohort). The 3 cohorts were matched for age, curative treatment for gastric cancer, Helicobacter pylori therapy, and propensity scores comprised of sex, comorbidities, and concomitant medication usage. The primary outcome is the hazard ratio (HR) of all-cause mortality.

RESULTS

After matching, we identified 1286, 1286, and 5144 patients for the <2 Y, 2 to 5 Y, and >5 Y cohorts. Compared with the >5 Y cohort, the HR of all-cause mortality for the <2 Y and 2 to 5 Y cohorts was 0.80 (95% confidence interval [CI], 0.72-0.89; P < .001) and 0.83 (95% CI, 0.76-0.91; P < .001), respectively. The HRs of gastric cancer-specific mortality were significantly lower in the <2 Y (0.80; 95% CI, 0.71-0.91; P < .001) and 2 to 5 Y cohorts (0.83; 95% CI, 0.75-0.93; P < .001).

CONCLUSIONS

Patients with gastric cancer who had a gastroscopy performed within 5 years before the cancer diagnosis had significantly lower mortality. Our results may support the role of repeat endoscopic examination or surveillance endoscopy in selected patients.

Germline Variants in DNA Repair Genes, Diagnostic Radiation, and Risk of Thyroid Cancer

Background: Radiation exposure is a well-documented risk factor for thyroid cancer; diagnostic imaging represents an increasing source of exposure. Germline variations in DNA repair genes could increase risk of developing thyroid cancer following diagnostic radiation exposure. No studies have directly tested for interaction between germline mutations and radiation exposure.Methods: Using data and DNA samples from a Connecticut population-based case-control study performed in 2010 to 2011, we genotyped 440 cases of incident thyroid cancer and 465 population-based controls for 296 SNPs in 52 DNA repair genes. We used multivariate unconditional logistic regression models to estimate associations between each SNP and thyroid cancer risk, as well as to directly estimate the genotype-environment interaction between each SNP and ionizing radiation.Results: Three SNPs were associated with increased risk of thyroid cancer and with thyroid microcarcinoma: HUS rs2708896, HUS rs10951937, and MGMT rs12769288. No SNPs were associated with increased risk of larger tumor (>10 mm) in the additive model. The gene-environment interaction analysis yielded 24 SNPs with P_interaction < 0.05 for all thyroid cancer, 12 SNPs with P_interaction < 0.05 for thyroid microcarcinoma, and 5 SNPs with P_interaction < 0.05 for larger tumors.Conclusions: Germline variants in DNA repair genes are associated with thyroid cancer risk and are differentially associated with thyroid microcarcinoma and large tumor size. Our study provides the first evidence that germline genetic variations modify the association between diagnostic radiation and thyroid cancer risk.Impact: Thyroid microcarcinoma may represent a distinct subset of thyroid cancer. The effect of diagnostic radiation on thyroid cancer risk varies by germline polymorphism. Cancer Epidemiol Biomarkers Prev; 27(3); 285-94. ©2017 AACR.

Increased expression of hepcidin and associated upregulation of JAK/STAT3 signaling in human gastric cancer

Gastric cancer is one of the most common malignancies with high cancer-associated mortality rate globally. Hepcidin is the peptide hormone, which is critically important in the regulation of systemic iron homeostasis. Cumulating evidence has reported that the disturbed local expression of hepcidin may serve as a predictive biomarker in assessing the clinical outcomes in a range of cancer types. However, the expression profile of hepcidin in human gastric cancer is remains to be investigated. In the present retrospective study, using archived paraffin-embedded tissue blocks, the local production of hepcidin by immunohistochemical analysis was detected, and then its correlation with clinicopathological characteristics in human gastric cancer was evaluated. In parallel, using western blotting, quantitative reverse transcription polymerase chain reaction and chromatin immunoprecipitation assay, the local status of Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) signaling in response to inflammatory stimuli mediated by interleukin (IL)-6, which in turn regulates transcriptional activity of hepcidin gene (HAMP) was also assessed. The results indicated that, the local production of hepcidin was significantly elevated in tumor tissues compared with adjacent non-tumor tissues, and was tightly correlated with increasing tumor stages according to the tumor node metastasis (TNM) classification. In addition, JAK/STAT3 signaling and the STAT3 binding affinity to the HAMP gene promoter were significantly enhanced, in parallel with an increased expression of hepcidin, in tumor tissues compared with adjacent non-tumor tissues. Collectively, the present study indicated that local expression of hepcidin in gastric cancer tumor tissues was positively correlated with increasing tumor stages, which may be closely associated with the upregulation of IL-6-mediated JAK/STAT3 signaling in human gastric cancer.

Long noncoding RNAs as auxiliary biomarkers for gastric cancer screening: A pooled analysis of individual studies

Background

Long non-coding RNAs (lncRNAs) are highlighted as novel cancer biomarkers with great promise. Herein, we focused on summarizing the overall diagnostic performance of lncRNAs for gastric cancer (GC).

Methods

Publications fulfilling the search criteria were selected from the online databases. Study quality was assessed according to the Quality Assessment for Studies of Diagnostic Accuracy (QUADAS) checklist. The summary receiver operator characteristic (SROC) curve was plotted using a bivariate meta-analysis model. Statistical analysis was performed based on the platforms of STATA 12.0 and Meta-Disc 1.4 software.

Results

Fifteen studies with 1252 patients and 1283 matched controls were included. The pooled sensitivity and specificity for lncRNA expression profile in differentiating GC patients from cancer-free individuals were 0.68 (95%CI: 0.61-0.74) and 0.79 (95%CI: 0.72-0.84), respectively, corresponding to an area under curve (AUC) of 0.80. Moreover, the stratified analyses demonstrated that plasma-based lncRNA profiling harbored higher accuracy than that tissue-based assay (specificity: 0.80 versus 0.75; AUC: 0.84 versus 0.77).

Conclusions

LncRNA profiling hallmarks a moderate diagnostic value in the management of GC and that lncRNA expression patterns may potentially be utilized as auxiliary biomarkers in confirming GC.

MDM2 binding protein as a predictor of metastasis and a novel prognostic biomarker in patients with gastric cancer

MDM2 binding protein (MTBP) has been revealed to be involved in cancer progression and metastasis. However, the role and clinical implication of MTBP expression in gastric cancer (GC) remains poorly understood. The present study aimed to investigate the clinicopathological significance of MTBP and the prognostic determinant in GC. The expression level of MTBP was examined in cancerous and matched adjacent noncancerous gastric mucosa tissues by reverse transcription-quantitative polymerase chain reaction and western blotting. MTBP expression levels were evaluated by immunohistochemical analysis of tissue microarrays for 352 patients, and association between the expression levels and prognosis in patients with GC were investigated. Kaplan-Meier analysis and Cox's regression models were used to investigate the associations between MTBP expression and prognosis of GC patients. The results of the present study revealed decreased MTBP mRNA (P=0.005) and protein (P=0.001) expression levels in tumor tissue compared with in matched adjacent normal tissue mucosa. MTBP expression level in GC was associated with gender (P=0.026), lymph node metastasis (P<0.001), distant metastasis (P=0.026) and pathological tumor-node-metastasis stage (P<0.001). Kaplan-Meier survival analysis demonstrated that patients with high MTBP expression levels exhibited longer survival times compared with patients with low MTBP expression levels. The multivariate logistic regression analysis revealed that MTBP was independently associated with the presence of lymph node [OR, 0.282; 95% confidence interval (CI), 0.161–0.494; P<0.001] and distant metastasis (OR, 0.365; 95% CI, 0.138–0.965; P=0.042). Furthermore, the multivariate Cox analysis revealed that low MTBP expression level was significantly associated with longer overall survival time and was recognized as an independent prognostic factor of patient's survival. MTBP expression level was significantly associated with progression and metastasis in GC, suggesting that MTBP may be used as a predictive marker for patient prognosis of GC.

Association of genetic variations in IL-6/IL-6R pathway genes with gastric cancer risk in a Chinese population

Interleukin-6 (IL-6) and its receptor (IL-6R) were regarded to be responsible for the occurrence of gastric cancer for their regulation roles in the inflammation. The genetic variations in these two genes (IL-6: rs6949149, rs1800796, rs10499563 and IL-6R: rs2228145) have been suggested to be associated with gastric cancer risk. However, the published results were inconsistent among subjects of different ethnicity. To evaluate such an association in Chinese population, we carried out this case-control study based on 473 patients with gastric cancer and 474 healthy controls, whose genotypes were detected by the Sequenom MassARRAY platform, and Helicobacter pylori infection was assessed by immunogold testing kit. This study showed that rs1800796 CG genotype was associated with decreased risk of gastric cancer (adjusted OR=0.75, 95% CI: 0.57-0.99, p=0.043). The stratified analysis revealed that, in the Helicobacter pylori negative infection subgroup, rs2228145 AC (adjusted OR=0.64, 95% CI: 0.42-0.97) and AC/CC (adjusted OR=0.66, 95% CI: 0.45-0.99) genotypes were associated with decreased risk of gastric cancer, respectively. In contrast, in the Helicobacter pylori positive infection subgroup, rs10499563 TC (adjusted OR=0.64, 95% CI: 0.43-0.95), CC (adjusted OR=0.35, 95% CI: 0.14-0.90), TC/CC (adjusted OR=0.59, 95% CI: 0.40-0.87) genotype were associated with decreased gastric cancer risk, respectively. Moreover, in the male subgroup, rs1800796 CG (adjusted OR=0.61, 95% CI: 0.44-0.84) and CG/GG (adjusted OR=0.67, 95% CI: 0.49-0.91) genotype were associated with decreased risk of gastric cancer, respectively. In short, this study suggested that IL-6R rs2228145 and IL-6 rs10499563 genotype were associated with decreased risk of gastric cancer for the individuals with negative and positive Helicobacter pylori infection.

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.