Multifactorial etiology of gastric cancer

H. pylori-induced NF-κB-PIEZO1-YAP1-CTGF axis drives gastric cancer progression and cancer-associated fibroblast-mediated tumour microenvironment remodelling

BACKGROUND

Gastric cancer (GC) is one of the most common tumours in East Asia countries and is associated with Helicobacter pylori infection. H. pylori utilizes virulence factors, CagA and VacA, to up-regulate pro-inflammatory cytokines and activate NF-κB signaling. Meanwhile, the PIEZO1 upregulation and cancer-associated fibroblast (CAF) enrichment were found in GC progression. However, the mechanisms of PIEZO1 upregulation and its involvement in GC progression have not been fully elucidated.

METHODS

The CAF enrichment and clinical significance were investigated in animal models and primary samples. The expression of NF-κB and PIEZO1 in GC was confirmed by immunohistochemistry staining, and expression correlation was analysed in multiple GC datasets. GSEA and Western blot analysis revealed the YAP1-CTGF axis regulation by PIEZO1. The stimulatory effects of CTGF on CAFs were validated by the co-culture system and animal studies. Patient-derived organoid and peritoneal dissemination models were employed to confirm the role of the PIEZO1-YAP1-CTGF cascade in GC.

RESULTS

Both CAF signature and PIEZO1 were positively correlated with H. pylori infection. PIEZO1, a mechanosensor, was confirmed as a direct downstream of NF-κB to promote the transformation from intestinal metaplasia to GC. Mechanistic studies revealed that PIEZO1 transduced the oncogenic signal from NF-κB into YAP1 signaling, a well-documented oncogenic pathway in GC progression. PIEZO1 expression was positively correlated with the YAP1 signature (CTGF, CYR61, and c-Myc, etc.) in primary samples. The secreted CTGF by cancer cells stimulated the CAF infiltration to form a stiffened collagen-enrichment microenvironment, thus activating PIEZO1 to form a positive feedback loop. Both PIEZO1 depletion by shRNA and CTGF inhibition by Procyanidin C1 enhanced the efficacy of 5-FU in suppressing the GC cell peritoneal metastasis.

CONCLUSION

This study elucidates a novel driving PIEZO1-YAP1-CTGF force, which opens a novel therapeutic avenue to block the transformation from precancerous lesions to GC. H. pylori-NF-κB activates the PIEZO1-YAP1-CTGF axis to remodel the GC microenvironment by promoting CAF infiltration. Targeting PIEZO1-YAP1-CTGF plus chemotherapy might serve as a potential therapeutic option to block GC progression and peritoneal metastasis.

Detection of Human Boca Virus in Gastric Adenocarcinoma

Background: Gastric cancer is one of the most common cancers worldwide. Human bocavirus (HBoV), a recently isolated virus, has been investigated for its role in many respiratory and enteric diseases. Few studies have reported its presence in solid tumors, such as lung and colon cancers. The aim of this study was to detect the presence of the HBoV1 genome in gastric adenocarcinoma, which has not yet been evaluated. Methods: Formalin-fixed paraffin-embedded (FFPE) blocks of 189 gastric tumors and 50 blocks of non-tumor gastric tissue products from elective weight reduction operations were collected. DNA extraction and real-time polymerase chain reaction (PCR) were performed for HBoV1 detection. DNA sequencing was performed using ABI Genetic Analyzer series 3500. Results: The mean age of the patients was 60±13.33 years. Tumors were more common in males than females (2.5/1). HBoV1 PCR was positive in 34 (18%) cases of GC and 10 (20%) cases of chronic gastritis (P>0.05). There was no association between age, sex, stage, and histologic subtype of the tumor and HBoV1 positivity (P>0.05) in tumor samples. The rate of intestinal metaplasia and presence of lymphoid stroma were also not more frequent in HBoV1-positive tumors (P>0.05). Conclusion: The HBoV1 can be detected in a relatively high proportion of Iranian patients with gastric cancer (18%) with no predilection for specific subtypes and no association with the degree of lymphocytic infiltration. HBoV1 can also be observed in approximately 20% of chronic gastritis cases. Further comprehensive studies are needed to elucidate the role of HBoV1 in gastric cancer development.

Chalcone Derivatives with a High Potential as Multifunctional Antioxidant Neuroprotectors

A systematic, rational search for chalcone derivatives with multifunctional behavior has been carried out, with the support of a computer-assisted protocol (CADMA-Chem). A total of 568 derivatives were constructed by incorporating functional groups into the chalcone structure. Selection scores were calculated from ADME properties, toxicity, and manufacturability descriptors. They were used to select a subset of molecules (23) with the best drug-like behavior. Reactivity indices were calculated for this subset. They were chosen to account for electron and hydrogen atom donating capabilities, which are key processes for antioxidant activity. The indexes showed that four chalcone derivatives (dCHA-279, dCHA-568, dCHA-553, and dCHA-283) are better electron and H donors than the parent molecule and some reference antioxidants (Trolox, ascorbic acid, and α-tocopherol). In addition, based on molecular docking, they are predicted to act as catechol-O-methyltransferase (COMT), acetylcholinesterase (AChE), and monoamine oxidase B (MAO-B) inhibitors. Therefore, these four molecules are proposed as promising candidates to act as multifunctional antioxidants with neuroprotective effects.

CADMA-Chem: A Computational Protocol Based on Chemical Properties Aimed to Design Multifunctional Antioxidants

A computational protocol aimed to design new antioxidants with versatile behavior is presented. It is called Computer-Assisted Design of Multifunctional Antioxidants and is based on chemical properties (CADMA-Chem). The desired multi-functionality consists of in different methods of antioxidant protection combined with neuroprotection, although the protocol can also be used to pursue other health benefits. The dM38 melatonin derivative is used as a study case to illustrate the protocol in detail. This was found to be a highly promising candidate for the treatment of neurodegeneration, in particular Parkinson's and Alzheimer's diseases. This also has the desired properties of an oral-drug, which is significantly better than Trolox for scavenging free radicals, and has chelates redox metals, prevents the ●OH production, via Fenton-like reactions, repairs oxidative damage in biomolecules (lipids, proteins, and DNA), and acts as a polygenic neuroprotector by inhibiting catechol-O-methyl transferase (COMT), acetylcholinesterase (AChE) and monoamine oxidase B (MAOB). To the best of our best knowledge, CADMA-Chem is currently the only protocol that simultaneously involves the analyses of drug-like behavior, toxicity, manufacturability, versatile antioxidant protection, and receptor-ligand binding affinities. It is expected to provide a starting point that helps to accelerate the discovery of oral drugs with the potential to prevent, or slow down, multifactorial human health disorders.

HuR confers IL-17a-induced migration and invasion of gastric cancer cells via upregulation of Snail translation

Human gastric cancer is a leading cause of cancer mortality in the world wide. We found that the expression of IL-17a was significantly increased in gastric cancer cells. Treatment with recombinant IL-17a (rIL-17a) can increase migration, invasion and epithelial to mesenchymal transition (EMT) of gastric cancer cells. Further, Snail, a key factor to regulate EMT, was significantly increased in rIL-17a-treated gastric cancer cells. While knockdown of Snail can abolish IL-17a-induced EMT of gastric cancer cells. Mechanistically, IL-17a can promote the translation efficiency of Snail, while had no effect on its mRNA expression or protein stability. Further, we found that IL-17a can increase the expression of HuR, which markedly promoted translation of Snail mRNA. While knockdown of HuR can reverse rIL-17a-induced expression of Snail and EMT of gastric cancer cells. Collectively, our data suggested that HuR confers IL-17a induced migration and invasion of gastric cancer cells via upregulation of Snail translation.

Investigation of Cyclooxygenase-2 Gene Polymorphism in Patients with Gastric Cancer and Healthy Individuals in Northern Iran

Background: Gastric cancer is one of the most common types of cancer in the world. Cyclooxygenase-2 (COX-2) is a pro-inflammatory enzyme and an important mediator of tumor cell proliferation and angiogenesis. Objectives: The aim of this study was to investigate the relationship between COX-2 gene polymorphism and the risk of developing gastric cancer. Methods: This case-control study was carried out on 150 patients with gastric cancer and 150 healthy individuals. Genomic DNA was extracted using a modified method of protein precipitation at high salt concentrations. Polymorphisms of the COX-2 gene were investigated by polymerase chain reaction-restriction fragment length polymorphism analysis. Results: In this study, the frequency of GG genotype and CC genotype was significantly higher in patients with gastric cancer and healthy individuals, respectively (P < 0.05). However, the frequency of CC genotype did not significantly differ between the 2 study groups. Conclusions: We demonstrated that the homozygous GG genotype of COX-2 is significantly more frequent in patients with gastric cancer compared to healthy individuals. This could indicate the possible role of COX-2 in the development or progression of gastric cancer.

Association between triglyceride-glucose index and gastric carcinogenesis: a health checkup cohort study

BACKGROUND

We aimed to investigate the association between the triglyceride-glucose (TyG) index and gastric carcinogenesis, including precancerous conditions such as dysplasia, atrophic gastritis, and intestinal metaplasia.

METHODS

Patients who received an upper endoscopic assessment at a medical center were included. The enrolled patients were divided into four categories according to their TyG index quartile (Q). To evaluate the relationship between increase of TyG index and gastric cancer, we analyzed the patients who received a health checkup twice. Moreover, receiver-operating characteristic curve analysis was used to establish cut-off value of the TyG index for gastric cancer.

RESULTS

Of 127,564 enrolled patients, 43,525 (34.1%) and 186 (0.1%) were diagnosed with precancerous conditions and gastric cancer, respectively. The odds ratios (ORs) of precancerous conditions given TyG index progressively increased across quartiles: using Q1 as the reference: Q2 (OR = 1.403, P < 0.001), Q3 (OR = 1.646, P < 0.001), and Q4 (OR = 1.656, P < 0.001). The ORs of gastric cancer also increased according to the quartiles: Q2 (OR = 1.619, P = 0.045), Q3 (OR = 2.180, P = 0.004), and Q4 (OR = 2.363, P = 0.001). Moreover, the increase in TyG index between baseline and follow-up tests was more significant in gastric cancer group than in control group (P = 0.001). The optimal cut-off value for predicting gastric cancer was 9.73.

CONCLUSIONS

The TyG index may be a novel predictive biomarker for gastric carcinogenesis. Notably, increase in the TyG index is significantly associated with gastric cancer.

Polymorphism of MUC1 Gene in Vietnamese Gastric Cancer Patients: A Multicenter Case-Control Study

Background

A few studies revealed that the polymorphisms of Mucin 1 gene have a role and significance as a susceptible factor contributing to gastric cancer. To better understand the roles of two MUC1 genotype polymorphisms of rs4072037 and rs2070803 in the development of gastric cancer in Vietnamese population, a multicenter, large-sample, case-control study was conducted to investigate the potential association of these single-nucleotide polymorphisms (SNPs) of MUC1 gene with gastric cancer risk and to evaluate the combination factors in relation with these SNPs.

Methods

This case-control study included 302 gastric cancer patients and 304 controls at four national medical hospitals between 2016 and 2018. All participants were interviewed for sociodemographic characteristics, smoking and drinking status, and personal and family history of gastric diseases. Genotyping was done using polymerase chain reaction-restriction fragment length polymorphism analysis. The association of SNPs with gastric cancer was explored using logistic regression models.

Results

AA genotype for rs4072037 was significantly associated with increased gastric cancer. Those with AA genotype had higher gastric cancer risk than had patients with AG (OR: 2.09, 95% CI: 1.48-2.96) and a combination of AG+GG (OR: 1.85, 95% CI: 1.33-2.56). In rs2070803, GG genotype increased gastric cancer risk when compared with AG (OR: 1.97, 95% CI: 1.39-2.80) and AG+AA (OR: 1.71, 95% CI: 1.23-2.39). AG genotypes in both SNPs decreased gastric cancer risk when compared with homogenous genotype, more specifically AA (OR: 0.51, 95% CI: 0.35-0.72) and GG (OR: 0.58, 95% CI: 0.35-0.97). These genotypes in combination with above-60-year-old age, male gender, alcoholism, and personal history of gastric disease were also significantly elevated risk factors for gastric cancer.

Conclusions

rs4072037 and rs2070803 of Mucin 1 genes are two genotypic risk factors for gastric cancer. Those in combination with gender, family history, smoking, and drinking habits significantly increase the risk of gastric cancer.

ELK4 promotes the development of gastric cancer by inducing M2 polarization of macrophages through regulation of the KDM5A-PJA2-KSR1 axis

Background

We tried to elaborate the molecular mechanism of ETS-like transcription factor 4 (ELK4) affecting gastric cancer (GC) progression through M2 polarization of macrophages mediated by lysine-specific demethylase 5A (KDM5A)-Praja2 (PJA2)-kinase suppressor of ras 1 (KSR1) axis.

Methods

GC expression dataset was obtained from GEO database, and the downstream regulatory mechanism of ELK4 was predicted. Tumor-associated macrophages (TAMs) were isolated from GC tissues. The interaction among ELK4, KDM5A, PJA2 and KSR1 was analyzed by dual luciferase reporter gene, ChIP and Co-IP assays. The stability of KSR1 protein was detected by cycloheximide (CHX) treatment. After TAMs were co-cultured with HGC-27 cells, HGC-27 cell biological processes were assessed through gain- and loss-of function assays. Tumorigenicity was detected by tumorigenicity test in nude mice.

Results

In GC and TAMs, ELK4, KDM5A and KSR1 were highly expressed, while PJA2 was lowly expressed. M2 polarization of macrophages promoted the development of GC. ELK4 activated KDM5A by transcription and promoted macrophage M2 polarization. KDM5A inhibited the expression of PJA2 by removing H3K4me3 of PJA2 promoter, which promoted M2 polarization of macrophages. PJA2 reduced KSR1 by ubiquitination. ELK4 promoted the proliferative, migrative and invasive potentials of GC cells as well as the growth of GC xenografts by regulating KSR1.

Conclusion

ELK4 may reduce the PJA2-dependent inhibition of KSR1 by transcriptional activation of KDM5A to promote M2 polarization of macrophages, thus promoting the development of GC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02915-1.

Dysregulation of lncRNA in Helicobacter pylori-Infected Gastric Cancer Cells

Helicobacter pylori (H. pylori) infection is the most common cause of gastric cancer (GC). This microorganism is genetically diverse; GC is caused by several genetic deregulations in addition to environmental factors and bacterial virulence factors. lncRNAs (long noncoding RNAs) are significant biological macromolecules in GC, have specific functions in diseases, and could be therapeutic targets. Altered lncRNAs can lead to the abnormal expression of adjacent protein-coding genes, which may be important in cancer development. Their mechanisms have not been well understood, so we are going to investigate the risk of GC in a population with both high lncRNA and H. pylori infection.

Profile of Helicobacter pylori cagA &vacA genotypes and its association with the spectrum of gastroduodenal disease

PURPOSE

Globally, H. pylori virulence factors cagA and vacA genotypes and its variation is leading to the austere form of the gastroduodenal disease. Our objectives were to detect H. pylori in dyspeptic patients from biopsy samples with the validation of the various existing diagnostic tools and to screen the cagA, vacA genotypes profile from biopsy specimens and how it impacts in progression of gastroduodenal disease in southern India.

METHODS

374 patients who attended endoscopy unit at Kasturba Hospital, Manipal with their consent obtained their biopsies. H. pylori were detected by HPE, Culture, RUT and PCR and its virulence gene were patterned with PCR.

RESULTS

The positive rate of H. pylori by HPE, RUT, Culture and PCR were 51.33%, 47.1%, 32.4% and 50.3% respectively and comparison by Bayesian LCMs analysis showed PCR is superior among them. The frequency of H. pylori virulence gene viz cagPAI (cagA) were 80.9%, and vacA alleles-s1m1 (42%), s1m2 (33%) and s2m2 (25%) genotypes by PCR respectively. Four combinations of cagA/vacA genotypes were noted, majority of strains harboured cagA⁺/vacA s1m1 genotypes (42.6%), interestingly this hyper-virulent strain more frequently seen in severe gastroduodenal disease whereas cagPAI negative strains as well as cagA^-/vacA s2m2 combinations (19.1%) are seen most commonly in functional dyspepsia cases and depicted significant association by Chi-square test.

CONCLUSIONS

This study validates and compares the existing diagnostic methods for detecting H. pylori in biopsies. Also, it reveals some pattern of virulence gene combination will play a vital role in disease progression.

Evaluation of the PTEN and circRNA-CDR1as Gene Expression Changes in Gastric Cancer and Normal Cell Lines Following the Exposure to Weak and Moderate 50 Hz Electromagnetic Fields

Background: Attention to the electromagnetic exposure as a targeted tumor therapy has been recently increasing. Objectives: The aim of the current study was to investigate the effect of continuous and discontinuous electromagnetic fields on cell viability as well as phosphatase and tensin homolog (PTEN) and circular (circ)-RNA CDR1as genes expression in the normal and gastric cancer (GC) cell lines. Methods: After preparing gastric cancer cell lines (AGS) and normal cells (HU02 line), they were exposed to magnetic flux densities of 0.25, 0.5, 1, and 2 mT continuously and discontinuously (1h on/1h off) for 18 hours. The 3-(4,5-dimethylthiazoyl-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to evaluate cell viability. In addition, after designing the primers, the expression of the PTEN and circ-CDR1as genes was studied using the real-time polymerase chain reaction (real-time-PCR) technique. The results were analyzed using SPSS software version 25. Results: The exposed normal and tumor cells to discontinuous electromagnetic fields resulted in increasing of cell survival rate in both normal and tumor cells. In contrast, the exposure of continuous electromagnetic field showed no effect on the viability of the normal and tumor cells at intensities of 0.25, 0.5, and 1 mT. The electromagnetic field showed a significant effect on the expression of the circ-CDR1as gene and this effect depended on the intensity of the electromagnetic field used and the cell type. We have found that the activity of PTEN gene in the normal and tumor cells increased and decreased with increasing intensity of discontinuous electromagnetic field, respectively. Conclusions: In general, the effect of electromagnetic field on gastric cancer seems to depend on the kind of exposure as well as an extent of intensity and can be used for cancer therapeutic purposes. However, more research is needed on this subject.

Correlations of SNHG5 genetic polymorphisms with susceptibility and prognosis to gastric cancer in a Chinese population

The most studied genetic polymorphisms associated with gastric cancer (GC) risk are located in protein-coding genes. However, these sited in long noncoding RNA (lncRNA) are not adequately explored yet. Here, we designed a case-control study of 848 cases and 880 controls to investigate the associations of polymorphisms (rs61396151, rs1059307, rs11961028, rs9351065) in lncRNA SNHG5 with the risk and prognosis of GC. The results indicate rs61396151 associated with decreased risk of GC (OR = 0.78, 95% CI = 0.62-0.96), but there were no correlations observed with the clinicopathological features of GC (P > 0.05). However, the CA genotype of rs61396151 was correlated with poor overall survival rate in a multivariate cox regression model (HR = 1.91, P = 0.040), but it was reversed with adjustment for age, gender and TNM stage (HR = 1.35, P = 0.213). Collectively, our results highlight the importance of SNHG5-related polymorphisms to GC susceptibility and prognosis.

Bayesian Profile Regression to Deal With Multiple Highly Correlated Exposures and a Censored Survival Outcome. First Application in Ionizing Radiation Epidemiology

As multifactorial and chronic diseases, cancers are among these pathologies for which the exposome concept is essential to gain more insight into the associated etiology and, ultimately, lead to better primary prevention strategies for public health. Indeed, cancers result from the combined influence of many genetic, environmental and behavioral stressors that may occur simultaneously and interact. It is thus important to properly account for multifactorial exposure patterns when estimating specific cancer risks at individual or population level. Nevertheless, the risk factors, especially environmental, are still too often considered in isolation in epidemiological studies. Moreover, major statistical difficulties occur when exposures to several factors are highly correlated due, for instance, to common sources shared by several pollutants. Suitable statistical methods must then be used to deal with these multicollinearity issues. In this work, we focused on the specific problem of estimating a disease risk from highly correlated environmental exposure covariates and a censored survival outcome. We extended Bayesian profile regression mixture (PRM) models to this context by assuming an instantaneous excess hazard ratio disease sub-model. The proposed hierarchical model incorporates an underlying truncated Dirichlet process mixture as an attribution sub-model. A specific adaptive Metropolis-Within-Gibbs algorithm-including label switching moves-was implemented to infer the model. This allows simultaneously clustering individuals with similar risks and similar exposure characteristics and estimating the associated risk for each group. Our Bayesian PRM model was applied to the estimation of the risk of death by lung cancer in a cohort of French uranium miners who were chronically and occupationally exposed to multiple and correlated sources of ionizing radiation. Several groups of uranium miners with high risk and low risk of death by lung cancer were identified and characterized by specific exposure profiles. Interestingly, our case study illustrates a limit of MCMC algorithms to fit full Bayesian PRM models even if the updating schemes for the cluster labels incorporate label-switching moves. Then, although this paper shows that Bayesian PRM models are promising tools for exposome research, it also opens new avenues for methodological research in this class of probabilistic models.

Prediction of gastric cancer risk: association between ZBTB20 genetic variance and gastric cancer risk in Chinese Han population

Background: Gastric cancer (GC) is a complex multifactorial disease. Previous studies have revealed genetic variations associated with the risk of gastric cancer. The purpose of the present study was to determine the correlation between single-nucleotide polymorphisms (SNPs) of ZBTB20 and the risk of gastric cancer in Chinese Han population.

Methods: We conducted a ‘case–control’ study involving 509 GC patients and 507 healthy individuals. We selected four SNPs of ZBTB20 (10934270 T/C, rs9288999 G/A, rs9841504 G/C and rs73230612 C/T), and used logistic regression to analyze the relationship between those SNPs and GC risk under different genetic models; multi-factor dimensionality reduction (MDR) was used to analyze the interaction of “SNP–SNP” in gastric cancer risk; ANOVA and univariate analysis were used to analyze the differences in clinical characteristics among different genotypes.

Results: Our results showed that ZBTB20 rs9288999 is a protective factor for the risk of gastric cancer in multiple genetic models, of which the homozygous model is the most significant (OR = 0.48, P=0.0003); we also found that rs9288999 showed a significant correlation with reducing the risk of gastric cancer in different subgroups (BMI; age; gender; smoking or drinking status; adenocarcinoma); rs9841504 is associated with increased GC risk in the participants with BMI>24 kg/m²; rs9841504 and rs73230612 are certainly associated with clinical characteristics of platelet and carbohydrate antigen 242, respectively.

Conclusion: Our results suggest that ZBTB20 rs9288999 may be important for reducing the risk of GC in the Chinese Han population.

Risk factors for gastric cancer and related serological levels in Fujian, China: hospital-based case-control study

OBJECTIVE

To explore the relationships between gastric cancer and serum pepsinogen I (PG I), PG II, PG I/II ratio, gastrin 17 (G-17) and Helicobacter pylori infection, and to investigate dietary and lifestyle risk factors for gastric cancer in Fujian Province, China.

DESIGN

A hospital-based, 1:1 matched case-control study.

SETTING

Patients with newly diagnosed gastric cancer were recruited from the Fujian Provincial Hospital and the No. 900 Hospital of the Joint Support Force of the Chinese People's Liberation Army between July 2014 and December 2016.

PARTICIPANTS

A total of 180 pairs of patients with gastric cancer and control subjects were recruited in the study, including 134 (74.4%) male pairs and 46 (25.6%) female pairs.

INVESTIGATION AND ANALYSIS MEASURES

Serological indicators were tested with ELISA kits. Dietary, lifestyle and psychological factors were investigated through face-to-face questionnaire. Relationships between gastric cancer and these influencing factors were examined by Χ2 test and conditional logistic regression.

RESULTS

Serum PG II and G-17 levels and H. pylori infection rate were higher in patients with gastric cancer than in control subjects (p<0.05), while PG I/II ratio was lower in patients with gastric cancer (p<0.05). Serum G-17 levels were higher in patients with corpus gastric cancer than in patients with antral gastric cancer (p<0.05). Serum PG II levels were higher in patients with advanced gastric cancer than in patients with early-stage cancer (p<0.05), however, PG I/II ratio was lower in patients with advanced-stage gastric cancer than in patients with early-stage cancer (p<0.05). Eating hot food (OR=2.32), eating pickled vegetables (OR=4.05) and often feel troubled (OR=2.21) were found to significantly increase the risk of gastric cancer (all p<0.05), while consuming onion or garlic (OR=0.35), drinking tea (OR=0.26), eating fresh fruits (OR=0.55), and high serum PG I (OR=0.99) or PG I/II ratio (OR=0.73) were found to be protective against gastric cancer.

CONCLUSION

Study results showed that serum PG, G-17 and H. pylori antibodies could be useful indicators for early diagnosis of gastric cancer. Increase in serum G-17 level might indicate the location of gastric cancer. Increase in serum PG II level and decrease in PG I/II ratio might imply the clinical stage. Eating hot food, eating pickled vegetables and often feel troubled may be risk factors for gastric cancer, while eating fresh fruits, eating onion or garlic, and drinking tea may be protective factors against the disease.

Outcome of FOLFOX and Modified DCF Chemotherapy Regimen in Patients with Advanced Gastric Adenocarcinoma

OBJECTIVES

Chemotherapy is used as an indispensable therapy for advanced gastric cancer. Different chemotherapy regimens have been used for this purpose. Toxicity due to the Chemotherapy drugs is one limiting factor. In this study we aim to compare the efficacy and toxicity of two regimens FOLFOX (leucoverin, 5-fluorouracil and oxaliplatin) and modified DCF (mDCF) (docetaxel, cisplatin, and 5-fluorouracil) in patients with advanced gastric adenocarcinoma.

METHODS

In this analytical cross-sectional study, 47 patients treated with FOLFOX regimen and 57 patients treated with mDCF regimen were recruited, Patients in both groups were compared for demographic findings, response rate, mortality rate, overall survival (OS) and progression free survival (PFS).

RESULTS

In FOLFOX and mDCF group, complete response (CR) occurred in 4.3% and 5.3%, partial response (PR) in 42.6% and 29.8%, stable disease in 34% and 52.6% and disease progression in 19.1% and 12.3%, respectively (p=0.25). Overall response rate was 48.9% and 56.1%, respectively. There was no significant difference between two regimens in OS and PFS (p=0.22). mDCF compared to FOLFOX had significantly higher hematologic, gastrointestinal complications, as well as creatinine rise, stomatitis and hair loss, but peripheral neuropathy was significantly lower.

CONCLUSION

The results of current study showed that in patients with advanced gastric adenocarcinoma, FOLFOX regimen compared to mDCF regimen have similar ORR, OS and PFS. Toxicity rate are also lower in FOLFOX group, thus it seems a better regimen for chemotherapy.<br />.

Gastric Dystemperament (Sue-mizaj) in Iranian Traditional Medicine

Background:

The stomach plays a vital role in the human body. Its clinical problems are very prevalent.

:

Nowadays, new branches of science have emerged because of human individual differences. Many medical schools such as Iranian Traditional Medicine (ITM) established the basis for the prevention, diagnosis, and treatment based on individual differences.

Objective:

The purpose of this study is to summarize identification indices of Gastric Dystemperament to help in better diagnosis.

Methods:

This was a qualitative review study. Definitions and symptoms of Stomach Dystemperament were derived from reliable sources of ITM from 900 AD to 1900 AD (Kamil-al-sinaa al Tibbiya, Teb-e-Akbari, Exir Azam, Al-Qanun fi al tibb, Mansouri Fi-al-teb, Al-Havi, Zakhire Kharazmshahi, Hidayat al-Muta’allemin fi al-tibb, Ferdos al-Hekmat fi al-tib, Sharh Al Qurashi al-Qanun, Sharh-e asbab al-Alamat) and English and Persian indices.

Results:

The most important factors and symptoms to be considered as gastric dystemperament include digestion, thirst, appetite, belching, bloating, gastric emptying time, burning stomach, reflux, gastric pain, the effect of food quality (coldness, heat, wet, dryness), mouth moisture and taste, tongue and mouth status, quality of body waste material (urine, stool), and palpation of the stomach area.

Conclusion:

Iranian Traditional Medicine sources have mentioned the indicators of gastric dystemperament, which can be used for more effective diagnosis and treatment and even prevention of gastric diseases.

Gastric cancer: epidemiology, biology, and prevention: a mini review

Gastric cancer is one of the most common causes of cancer-related mortality worldwide. The objective of this article is to review the epidemiology and biology of gastric cancer risk. This literature review explores the biological, clinical, and environmental factors that influence the rates of this disease and discuss the different intervention methods that may not only increase the awareness of gastric cancer but also increase screening in efforts to reduce the risk of gastric cancer. Helicobacter pylori infection is the primary risk factor for gastric cancer. Additional risk factors include geographical location, age, sex, smoking, socioeconomic status, dietary intake, and genetics. Primary and secondary prevention strategies such as dietary modifications and screenings are important measures for reducing the risk of gastric cancer. Interventions, such as H. pylori eradication through chemoprevention trials, have shown some potential as a preventative strategy. Although knowledge about gastric cancer risk has greatly increased, future research is warranted on the differentiation of gastric cancer epidemiology by subsite and exploring the interactions between H. pylori infection, genetics, and environmental factors. Better understanding of these relationships can help researchers determine the most effective intervention strategies for reducing the risk of this disease.

DNA Methylation Profiling of hTERT Gene Alongside with the Telomere Performance in Gastric Adenocarcinoma

PURPOSE

Epigenetic modification including of DNA methylation, histone acetylation, histone methylation, histon phosphorylation and non-coding RNA can impress the gene expression and genomic stability and cause different types of malignancies and also main human disorder. Conspicuously, the epigenetic alteration special DNA methylation controls telomere length, telomerase activity and also function of different genes particularly hTERT expression. Telomeres are important in increasing the lifespan, health, aging, and the development and progression of some diseases like cancer.

METHODS

This review provides an assessment of the epigenetic alterations of telomeres, telomerase and repression of its catalytic subunit, hTERT and function of long non-coding RNAs such as telomeric-repeat containing RNA (TERRA) in carcinogenesis and tumorgenesis of gastric cancer.

RESULTS

hTERT expression is essential and indispensable in telomerase activation through immortality and malignancies and also plays an important role in maintaining telomere length. Telomeres and telomerase have been implicated in regulating epigenetic factors influencing certain gene expression. Correspondingly, these changes in the sub telomere and telomere regions are affected by the shortening of telomere length and increased telomerase activity and hTERT gene expression have been observed in many cancers, remarkably in gastric cancer.

CONCLUSION

Epigenetic alteration and regulation of hTERT gene expression are critical in controlling telomerase activity and its expression. Graphical Abstract.

Long non-coding RNA GAS5 in human cancer

Long non-coding RNAs (lncRNAs) constitute a group of >200-nucleotide ncRNA molecules. lncRNAs regulate several cell functions, such as proliferation, apoptosis, invasion and metastasis. Meanwhile, lncRNAs are abnormally expressed in human malignancies, where they suppress or promote tumor growth. The present study focused on growth arrest-specific transcript 5 (GAS5), a well-known lncRNA that acts as a tumor suppressor but is suppressed in multiple types of cancer, including mammary carcinoma, prostate cancer, colorectal cancer, gastric cancer, melanoma, esophageal squamous cell carcinoma, lung cancer, ovarian cancer, cervical cancer, gliomas, osteosarcoma, pancreatic cancer, bladder cancer, kidney cancer, papillary thyroid carcinoma, neuroblastoma, endometrial cancer and liver cancer. Notably, GAS5 is overexpressed in liver cancer, potentially functioning as an oncogene. In the present study, the diagnostic and therapeutic roles of GAS5 in different tumors were reviewed, with a summary of the potential clinical application of the lncRNA, which may help identify novel study directions for GAS5.

The Bacterial Microbiota of Gastrointestinal Cancers: Role in Cancer Pathogenesis and Therapeutic Perspectives

The microbiota has an essential role in the pathogenesis of many gastrointestinal diseases including cancer. This effect is mediated through different mechanisms such as damaging DNA, activation of oncogenic pathways, production of carcinogenic metabolites, stimulation of chronic inflammation, and inhibition of antitumor immunity. Recently, the concept of "pharmacomicrobiomics" has emerged as a new field concerned with exploring the interplay between drugs and microbes. Mounting evidence indicates that the microbiota and their metabolites have a major impact on the pharmacodynamics and therapeutic responses toward anticancer drugs including conventional chemotherapy and molecular-targeted therapeutics. In addition, microbiota appears as an attractive target for cancer prevention and treatment. In this review, we discuss the role of bacterial microbiota in the pathogenesis of different cancer types affecting the gastrointestinal tract system. We also scrutinize the evidence regarding the role of microbiota in anticancer drug responses. Further, we discuss the use of probiotics, fecal microbiota transplantation, and antibiotics, either alone or in combination with anticancer drugs for prevention and treatment of gastrointestinal tract cancers.

Synthesis and characterization of alginate nanocarrier encapsulating Artemisia ciniformis extract and evaluation of the cytotoxicity and apoptosis induction in AGS cell line

The aim of this study was to synthesize the alginate nanogel encapsulating Artemisia ciniformis extract and to evaluate its apoptotic effects on AGS gastric cancer cells. Characterization of the synthesized nanogel was confirmed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), Dynamic light scattering method (DLS), and Zeta potential. The cytotoxic effects and apoptosis induction of A. ciniformis extract, nanogel encapsulating A. ciniformis extract and alginate nanogel alone were evaluated in the AGS cell line using MTT assay, Annexin-FITC, DAPI staining, cell cycle analysis, and real-time PCR for 24, 48 and 72 h. Anti-proliferative activity and apoptosis induction were observed in the cells treated with alginate nanogel encapsulating A. ciniformis extract and free extract. The alginate nanogel encapsulating A. ciniformis extract had greater potential for the induction of apoptosis than free extract. Flow cytometric results of the cell cycle showed that synthesized nanogel encapsulating A. ciniformis extract could inhibit cell proliferation and arrest the cell cycle at the G0/G1 phase. Induction of apoptosis occurred in a time-, and dose-dependent manner. Expression levels of pro-apoptotic genes were up-regulated. Down-regulation of anti-apoptotic and metastatic genes were detected. It can be concluded that nanogel encapsulating A. ciniformis extract would be a potent anticancer agent against AGS gastric cancer cells.

Association between polymorphisms in HLA-A, HLA-B, HLA-DR, and DQ genes from gastric cancer and duodenal ulcer patients and cagL among cagA-positive Helicobacter pylori strains: The first study in a Turkish population

Colonization of the human gastric mucosa by H. pylori may cause peptic and duodenal ulcers (DUs), gastric lymphomas, and gastric cancers. The cagL gene is a component of cag T4SS and is involved in cagA translocation into host. An association between the risk of gastric cancer and the type of HLA class II (DR and/or DQ) was suggested in different populations. The aim of this study was to investigate, the clinical association of the cagL gene with host HLA alleles in H. pylori strains that were isolated from patients with gastric cancer, DU, and non-ulcer dyspepsia (NUD) and to determine the HLA allele that confers susceptibility or resistance for the risk of gastric cancer and DU development in Turkish patients. A total of 94 patients (44 gastric cancer and 50 DU patients; 58 male, 36 female; mean age, 49.6 years), and 86 individuals (50 NUD patients and 36 persons with normal gastrointestinal system [NGIS]; 30 male, 56 female; mean age, 47.3 years) were included as the patient and the control groups, respectively. CagA and cagL were determined by PCR method. DNA from peripheral blood samples was obtained by EZ-DNA extraction kit. For HLA SSO typing, LIFECODES SSO Typing kits (HLA-A, HLA-B HLA-C, HLA-DRB1 and HLA-DQA1/B1 kits) were used. The CagL/CagA positivity distribution in the groups were as follows: 42 (95.4%) gastric cancer, 46 (92%) DU and, 34 (68%) NUD and no NGIS cases. The HLA-DQA1*01 (OR: 3.82) allele was significantly different, suggesting that these individuals with H. pylori strains harbouring the CagL/CagA positivity are susceptible to the risk of gastric cancer and DU, and the HLA-DQA1*05 (OR, 0.318) allele was suggested as a protective allele for the risk of gastric cancer and DU using univariate analyses. HLA-DQA1*01 (OR, 2.21), HLA-DQB1*06 (OR, 2.67), sex (male, OR, 2.27), and CagL/CagA/(<2) EPIYA C repeats (OR, 5.72) were detected independent risk factors that increased the risk of gastric cancer and DU using multivariate analyses. However, the HLA-DRB1*04 (OR, 0.28) allele was shown to be a protective allele, which decreased the risk of gastric cancer and DU. Gastric pathologies result from an interaction between bacterial virulence factors, host epigenetic and environmental factors, and H. pylori strain heterogeneity, such as genotypic variation among strains and variations in H. pylori populations within an individual host.

LIG3 gene polymorphisms and risk of gastric cancer in a Southern Chinese population

DNA ligase III (LIG3) has been implicated in the etiology of cancer. However, few studies have accessed the association of LIG3 single nucleotide polymorphisms (SNPs) with gastric cancer risk, especially in Chinese population. The current study was undertaken to investigate contribution of LIG3 gene polymorphisms to gastric cancer risk. We first applied TaqMan assay to genotype three LIG3 gene SNPs (rs1052536 C > T, rs3744356 C > T, rs4796030 A > C) in 1142 patients with gastric cancer and 1173 healthy controls. And then, we adopted unconditional multivariate logistic regression analysis to estimate the association between LIG3 SNP genotypes and gastric cancer risk. In all, no positive association was found between the three LIG3 SNPs and gastric cancer risk in single locus analysis or combined risk genotypes analysis. However, compared with participants with rs4796030 AA genotype, participants with the AC/CC had a decreased risk of developing tumors from cardia at an adjusted OR of 0.68 (95% CI = 0.48-0.96, P = 0.026). In addition, we found that participants harboring 2-3 risk genotypes were at a significantly increased risk of developing tumor from cardia (adjusted OR = 1.63, 95% CI = 1.16-2.28, P = 0.005). These results suggest that genetic variations in LIG3 gene may play a weak role in modifying the risk of gastric cancer. Future functional studies should be performed to elucidate the biological role of LIG3 polymorphisms in gastric cancer carcinogenesis.

Unequal burden of mortality from gastric cancer in Brazil and its regions, 2000-2015

BACKGROUND

Gastric cancer (GC) is an important cause of morbidity and mortality worldwide. However, population-based data on GC mortality dynamics in low and middle income countries are scarce.

METHODS

We analyzed GC mortality in Brazil based on all GC-related deaths registered 2000-2015.

RESULTS

A total of 17,374,134 deaths were recorded, with GC identified in 214,808 (1.24%) cases-203,941 (94.9%) as underlying cause, and 10,867 (5.1%) as associated cause of death. Adjusted rates for age and sex was 6.85 deaths/100,000 inhabitants [95% confidence interval (CI) 6.73-6.97]. The highest mortality rates were found in males [10.00; rate ratio (RR) 1.85; 95% CI 1.78-1.91; p < 0.0001] and patients ≥ 45 years of age (24.98; RR 3.79; 95% CI 3.55-4.05; p < 0.0001). The South (7.56; RR 1.62; 95% CI 1.50-1.76; p < 0.0001) and Southeast (7.36; RR 1.59; 95% CI 1.48-1.71; p < 0.0001) regions had the highest regional rates. Spatial and spatiotemporal high-risk mortality areas in 2004-2007 were located mainly in the South, Southeast, and Central-West regions. After 2008, the Northeast region became a high-risk area, especially Ceará State.

CONCLUSION

GC remains a significant public health problem with high mortality burden and unequal distribution in Brazilian states. The new patterns in poorer regions and the high risk in some specific populations show a clear process of epidemiological transition over time. There is a need to strengthen nationwide epidemiological monitoring, surveillance, prevention, and control for GC in the country.

Distribution of nucleotide variants in the DNA sequence of ERCC1 and XRCC1 genes and the effect of phenotype in patients with gastric cancer

BACKGROUND/AIMS

Gastric cancers vary across countries and ethnic groups. They are the second most common type of cancer worldwide. Dietary and non-dietary factors as well as genetic and epigenetic alterations of many mechanisms are implicated in the development of gastric cancer. We aimed to determine the sequence of possible nucleotide changes, polymorphisms, and mutations, and to establish genotype and phenotype relation by performing whole DNA sequence analysis of the XRCC1 and ERCC1 genes belonging to base excision repair (BER) and nucleotide excision repair (NER) family of DNA repair genes in patients with gastric cancer.

MATERIALS AND METHODS

We included 50 patients of both sexes who had received diagnosis of gastric cancer and 50 healthy people who showed same demographic traits that forms the control group. We analyzed the ERCC1 and XRCC1 genes by DNA sequence analysis on both groups. After the analysis, we compared the genotype-phenotype relation.

RESULTS

Neither patients nor the control group has any nucleotide replacement in any exon of ERCC1 genes. We could not detect significant difference between patients and healthy groups when we correlated genotype contribution of mutations Arg194Trp, Arg208His, Arg399Gln detected in the XRCC1 gene and allele frequency.

CONCLUSION

According to our study, the ERCC1 gene in Turkish population is not getting mutation in patients with gastric cancer and healthy individuals. Three mutations were detected in the XRCC1 gene, and these mutations were not associated with gastric cancer.

Expression and biological function of rhotekin in gastric cancer through regulating p53 pathway

Background/aim

Gastric cancer (GC) is one of a most threatening cancer globally. Rhotekin (RTKN), a Rho effector, has been reported to be upregulated in GC tissues. This study aimed to investigate the underlying regulatory roles of RTKN in the biological behavior of GC.

Methods

Real-time PCR and Western blotting were carried out to detect the mRNA and protein expression, respectively. Cell Counting Kit-8 and xenograft nude mice model were used to evaluate cell proliferation. Flow cytometry analysis was performed to assess cell cycle distribution and cell apoptosis.

Results

RTKN had high expression level in GC compared with normal tissues. RTKN expression strongly associated with tumor size, TNM stage, lymphnode metastasis and the poor prognosis of patients with GC. Downregulation of RTKN significantly repressed GC cell proliferation, but increased cell population in G1/S phase and induced cell apoptosis. Moreover, the RTKN expression level was related to the p53 signaling pathway and histone deacetylase (HDAC) Class I pathway. RTKN knockdown caused a notable increment in the acetylation level of p53 (Lys382), and the expression of p53-target genes (p21, Bax, and PUMA), as well as a reduction in the expression of a potential deacetylase for p53, HDAC1. Notably, downregulation of HDAC1 had similar effects as RTKN knockdown, and RTKN overexpression could hardly abrogate the effects of HDAC1 knockdown on GC cells.

Conclusion

RTKN could work as an oncogene via regulating HDAC1/p53 and may become a promising treatment strategy for GC.

ASSOCIATION OF INTERLEUKIN-10 -592A>C AND -819T>C POLYMORPHISMS WITH GASTRIC CANCER RISK: A SYSTEMATIC REVIEW AND META-ANALYSIS OF 44 CASE-CONTROL STUDIES

INTRODUCTION

A series of studies have evaluated the association between -592A>C and -819T>C polymorphisms in the promoter regions of Interleukin-10 (IL-10) and gastric cancer (GC) risk. However, the results remain inconclusive.

OBJECTIVE

To better understand the association of the polymorphisms with GC risk, we performed a comprehensive meta-analysis.

METHOD

An electronic search was performed of several databases to identify relevant studies up to April 2018.

RESULTS

A total of 44 case-control studies, including 26 studies on IL-10 -592A>C (5,332 cases and 8,272 controls) and 18 studies on IL-10 -819T>C (3,431 cases and 6,109 controls) were selected. Overall, -592A>C polymorphism was associated with the risk of GC under the heterozygote model (OR=1.153, 95% CI=1.020-1.305, p=0.023), but not -819T>C polymorphism. When stratified by ethnicity, significant association was only observed in the Asians under the allele model (OR=1.153, 95% CI=1.007-1.320, p=0.040) and the heterozygote model (OR=1.218, 95% CI=1.076-1.379, p=0.002) for -592A>C.

CONCLUSION

The current meta-analysis results inconsistent with previous meta-analyses; showed that the IL-10 -592A>C polymorphism, but not -819T>C polymorphism, may be contributed to the susceptibility of GC in overall and Asian populations.

Evaluation of serum markers for gastric cancer and its precursor diseases among high incidence and mortality rate of gastric cancer area

BACKGROUND

Mongolia has the highest mortality rate of gastric cancer. The early detection of cancer and down-staging screening for high risk patients are essential. Therefore, we aimed to validate serum markers for stratifying patients for further management.

METHODS

Endoscopy and histological examination were performed to determine high risk and gastric cancer patients. Rapid urease test, culture and histological tests were performed to diagnose Helicobacter pylori infection. Serum pepsinogen (PG) I and II and anti-H. pylori IgG were measured by ELISA. Receiver Operating Characteristic analysis was used to extract the best cut-off point.

RESULTS

Totally 752 non-cancer and 50 consecutive gastric cancer patients were involved. The corpus chronic gastritis (72%: 36/50 vs. 56.4%: 427/752), corpus atrophy (42.0%: 21/50 vs. 18.2%: 137/752) and intestinal metaplasia (IM) (64.0%: 32/50 vs. 21.5%: 162/752) were significantly higher in gastric cancer than non-cancer patients, respectively. Therefore, corpus chronic gastritis, corpus atrophy and IM were considered as high risk disease. The best serum marker to predict the high risk status was PGI/II < 3.1 (sensitivity 67.2%, specificity 61%) and PGI/II further reduced to < 2.2 (sensitivity 66%, specificity 65.1%) together with PGI < 28 ng/mL (sensitivity 70%, specificity 70%) were the best prediction for gastric cancer. The best cut-off point to diagnose H. pylori infection was anti-H. pylori IgG > 8 U/mL. Multivariate analysis showed that anti-H. pylori IgG > 8 U/mL and PGI/II < 3.1 increased risk for high risk status and PGI/II < 3.1 remained to increase risk for gastric cancer.

CONCLUSION

The serum diagnosis using PGI/II < 3.1 cut-off value is valuable marker to predict high risk patients for population based massive screening.

Association between Polymorphisms in Inflammatory Response-Related Genes and the Susceptibility, Progression and Prognosis of the Diffuse Histological Subtype of Gastric Cancer

The chronic inflammatory microenvironment and immune cell dysfunction have been described as critical components for gastric tumor initiation and progression. The diffuse subtype is related to poor clinical outcomes, pronounced inflammation, and the worst prognosis. We investigated the association of polymorphisms in inflammatory response-related genes (COX-2, OGG1, TNFB, TNFA, HSPA1L, HSPA1B, VEGFA, IL17F, LGALS3, PHB, and TP53) with gastric cancer susceptibility, progression and prognosis in a Brazilian sample, focusing on the diffuse subtype. We also performed the analysis regarding the total sample of cases (not stratified for tumor subtypes), allowing the comparison between the findings. We further investigated the polymorphisms in linkage disequilibrium and performed haplotype association analyses. In the case-control study, rs1042522 (TP53) was associated with a stronger risk for developing gastric cancer in the sample stratified for diffuse subtype patients when compared to the risk observed for the total cases; CTC haplotype (rs699947/rs833061/rs2010963 VEGFA) was associated with risk while rs699947 was associated with protection for gastric malignancy in the total sample. Regarding the associations with the clinicopathological features of gastric cancer, for the diffuse subtype we found that rs699947 and rs833061 (VEGFA) were associated with outcomes related to a worse progression while rs5275 (COX-2), rs909253 (TNFB), and rs2227956 (HSPA1L) were associated to a better progression of the disease. In the total sample, rs699947 and rs833061 (VEGFA), rs4644 (LGALS3), and rs1042522 (TP53) were able to predict a worse progression while rs5275 (COX-2), rs2227956 (HSPA1L), and rs3025039 (VEGFA) a better progression. Besides, rs909253 (TNFB) predicted protection for the overall and disease-free survivals for gastric cancer. In conclusion, these results helped us to clarify the potential role of these polymorphisms in genes involved in the modulation of the inflammatory response in the pathogenesis of gastric cancer.

Targeting of high mobility group A2 by small interfering RNA-loaded nanoliposome-induced apoptosis and migration inhibition in gastrointestinal cancer cells

BACKGROUND

Considering the complex nature of gastrointestinal cancer, different methods including surgery, radiotherapy, and chemotherapy are considered for the treatment. Novel strategies including silencing of oncogenes using safe delivery systems could be considered as a novel approach in colorectal cancer treatment. The aim of this study was to investigate the silencing effect of high mobility group A2 (HMGA2) small interfering RNA (siRNA)-loaded nanoliposomes on gastrointestinal cancers.

METHODS

The siRNA-lipoplexes were prepared using dioleoyl trimethylammonium propane (DOTAP)/cholesterol (Chol)/1, 2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) through the freeze-drying of a monophase solution method. The size, polydispersity index (PDI), and zeta-potential of nanoliposomes were determined using Zetasizer analyzer. The morphology of the nanoliposomes was determined by transmission electron microscopy (TEM). The agarose gel-retardation assay was carried out to confirm the loading of siRNAs into liposome. The silencing of the HMGA2 in cancer cells was evaluated by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The effect of liposomes on cell cytotoxicity was studied by MTT assay. The inhibitory effect of siRNA-loaded liposomes was evaluated by a wound-healing assay. The apoptosis induction was investigated via the annexin V/propidium iodide assay.

RESULTS

The size, PDI, and zeta-potential of the prepared liposomes were found to be 350 nm, 0.67, and 86.3 mV, respectively. They were spherical in shape and could efficiently associate with siRNA. The results of gene silencing showed that the optimum condition of HMGA2 silencing was 80 pmol HMGA2 and 24 hours after treatment in each cancer cell lines. MTT assays indicated that silencing of HMGA2 in optimal condition could reduce the viability of the cancer cells more than 60% in the three cell lines. The result of the apoptosis assay showed more than 50% of the cell deaths related to the apoptosis in all three cell lines. The gene expression evaluation confirmed that apoptosis was induced via the intrinsic pathway inducing both caspase-3 and -9 expressions. Also, the reduction in Bcl2 expression confirmed the activation apoptosis pathway in the treated cancer cells. The wound-healing assay showed the suppression of cancer cell migration after treatment with the prepared nanoliposomes.

CONCLUSION

The results of this study showed the HMGA2 siRNA-loaded nanoliposomes could be effective in the treatment of gastrointestinal cancers.

Supplementation with omega fatty acids increases the mRNA expression level of PLA2G4A in patients with gastric cancer

Background

Many lines of evidence suggest that arachidonic acid (AA)-based eicosanoid signaling pathway involved in development and progression of human cancers. Cytosolic phospholipase A2-α (cPLA2α) encoded by the PLA2G4A gene acts as an upstream regulator of eicosanoid signaling pathway through providing intracellular AA. The current study aimed to evaluate the effect of omega fatty acids on mRNA expression level of PLA2G4A in patients with gastric cancer (GC) and to assess the possible relation between its expression and clinicopathological features.

Methods

According to treatment strategy, 34 chemotherapy-naive patients were randomly divided into two groups including, treatment group I (17 subjects received cisplatin alone) and treatment group II (17 individuals received cisplatin plus omega fatty acids) in a double-blind manner. The gastric biopsies specimens were taken from subjects before and after treatment and then mRNA expression level of PLA2G4A was evaluated by quantitative real-time PCR procedure.

Results

The expression of the PLA2G4A gene at the protein level in the gastric biopsies samples was also determined by immunohistochemistry. Our findings revealed a significantly up-regulated expression of PLA2G4A mRNA in treatment group II after receiving cisplatin plus omega fatty acid compared to before treatment (P=0.003). In treatment group I, there was no significant difference in mRNA expression levels of PLA2G4A before and after treatment (P=0.790). We also found that mRNA expression of PLA2G4A in treatment group II was significantly associated with tumor size (P=0.007) and familial history (P=0.006).

Conclusions

This study provides evidence that supplementation with omega fatty acids increases the mRNA expression level of PLA2G4A in patients with GC and may be crucial in guarding the cell from transformation and carcinogenesis.

Polymorphisms of TGFBR1, TLR4 are associated with prognosis of gastric cancer in a Chinese population

Background

Helicobacter pylori (H. pylori)-induced gastric cancer is an intricate progression of immune response against H. pylori infection. IL-16, TGF-β1 and TLR4 pathways were the mediators involved in the immune response. We hypothesized that genetic variations in genes of these pathways have potential susceptibility to gastric cancer risk, and predict clinical outcomes of patients.

Methods

To investigate the susceptibility and prognostic value of genetic variations of IL-16, TGFBR1 and TLR4 pathways to gastric cancer, we performed a case–control study combined a retrospective study in a Chinese population. Genotyping for all polymorphisms was based on the Sequenom’s MassARRAY platform, and H. pylori infection was determined by using an immunogold testing kit.

Results

We found rs10512263 CC genotype was found to be a decreased risk of gastric cancer (CC vs. TT: adjusted OR = 0.54, 95% CI 0.31–0.97); however, rs334348 GG genotype was associated with increased risk of gastric cancer (GG vs. AA: adjusted OR = 1.51, 95% CI 1.05–2.18). We found that carriers harboring rs1927911 A allele (GA/AA) or rs10512263 C allele (CT/CC) have unfavorable survival time than none carriers (rs1927911: GA/AA vs. GG: adjusted HR = 1.27, 95% CI 1.00–1.63; rs10512263: CT/CC vs. TT: adjusted HR = 1.29, 95% CI 1.02–1.63) and that individuals harboring both two minor alleles (rs1927911 GA/AA and rs10512263 CT/CC) suffered a significant unfavorable survival (adjusted HR = 1.64, 95% CI 1.17–2.31).

Conclusion

In short, we concluded that two polymorphisms (rs334348, rs10512263) in TGFBR1 were associated with risk of gastric cancer, and that TLR4 rs1927911 and TGFBR1 rs10512263 were associated with clinical outcomes of gastric cancer patients.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0682-0) contains supplementary material, which is available to authorized users.

Protective Effects of Dioscorea batatas Flesh and Peel Extracts against Ethanol-Induced Gastric Ulcer in Mice

Gastric ulcer is a major digestive disorder and provoked by multifactorial etiologies, including excessive alcohol consumption. In this study, we examined the gastroprotective effect of aqueous and ethanolic extracts of Dioscorea batatas Decne (DBD; commonly called Chinese yam) flesh or peel against acidified ethanol-induced acute gastric damage in mice. Our findings demonstrated that oral supplementation of aqueous or ethanolic extracts of DBD flesh or peel before ulcer induction was significantly effective in macroscopically and histologically alleviating ethanol-induced pathological lesions in gastric mucosa, decreasing the plasma levels of inflammatory mediators, such as nitric oxide and interleukin-6, attenuating the gastric expression of cyclooxygenase-2, and increasing the gastric content of prostaglandin E₂. In particular, pretreatment with the flesh extract prepared in 60% ethanol prominently decreased the expression of biomarkers of oxidative stress, including the plasma levels of 8-hydroxy-2-guanosine and malondialdehyde, and restored heme oxygenase-1 expression and superoxide dismutase activity in the stomach. Overall, these findings suggest that the oral supplementation with DBD extract, especially flesh ethanol extract, prior to excessive alcohol consumption, may exert a protective effect against ethanol-induced gastric mucosal damage in vivo, presumably through the activation of the antioxidant system and suppression of the inflammatory response.

Polymorphism in the promoter region of lncRNA GAS5 is functionally associated with the risk of gastric cancer

BACKGROUND AND AIMS

Previous studies showed that down-regulation of GAS5 was involved in the development of gastric cancer (GC). However, the regulatory mechanism of down-expressed GAS5 in GC remains obscure. We aimed to investigate the role of rs145204276 of GAS5 in the development and metastasis process of GC.

METHODS

853 GC patients and 954 healthy controls were recruited. The variant rs145204276 was genotyped and the Chi² test was used to compare the frequency of the genotype and the allele between the patients and the controls. Odds ratio (OR) and 95% confidence intervals (95% CIs) were calculated to estimate the association of rs145204276 with the risk of development and metastasis of GC.

RESULTS

Patients were found to have significantly lower rate of genotype del/del than the controls (7.2% vs. 8.9%, P=0.016). The allele del was significantly associated with a decreased risk of GC (26.4% vs. 30.7%, P=0.005) with an OR of 0.81 (95% CI=0.70-0.94). Patients with allele del were less likely to develop lymph node metastasis (P=0.01), with an OR of 0.75 (95% CI=0.60-0.93). Comparably, rs145204276 was also significantly associated with a decreased risk of distant metastasis of GC (P=0.007; OR=0.55).

CONCLUSION

We confirmed that rs145204276 of GAS5 is a functional variant associated with the susceptibility and metastasis of GC. It plays a protective role in the development of GC possibly through the regulation of GAS5.

Association of IL10 gene promoter polymorphisms with risks of gastric cancer and atrophic gastritis

OBJECTIVE

To investigate the association between polymorphisms of the interleukin 10 ( IL10) gene and risk of gastric cancer (GC) and atrophic gastritis (AG).

METHODS

This study enrolled patients with GC, patients with AG and healthy control subjects. Demographic data were collected and the IL10 gene -1082A/G, -819C/T and -592A/C polymorphisms were genotyped. An enzyme-linked immunosorbent assay was performed to detect Helicobacter pylori infection.

RESULTS

The study enrolled 556 participants including 208 in the GC group, 116 in the AG group and 232 controls (CON group). In a recessive model of the IL10-819C/T polymorphism, a significantly decreased risk of GC was found compared with AG and non-cancer subjects, respectively (AG→GC: odds ratio OR 0.41; non-cancer→GC: OR 0.57). The CC genotype demonstrated a significantly increased risk of AG compared with CON. Similar significant results were detected in males and H. pylori-negative subgroups. The ACC haplotype was associated with a decreased risk of GC compared with AG. The ATC haplotype was associated with a decreased risk of AG compared with the CON group, but it was associated with an increased risk of GC compared with AG.

CONCLUSION

The IL10 gene promoter -819C/T (rs1800871) polymorphism was associated with the risk of GC and AG in a Chinese population.

CD133 Expression as a Helicobacter pylori-independent Biomarker of Gastric Cancer Progression

BACKGROUND/AIM

Gastric adenocarcinoma is the fourth most common cancer worldwide. While gastric cancer prevalence varies globally and incidence rates are decreasing in the West, many cases continue to be diagnosed at an advanced stage and the 5-year survival rate still falls below 30%. Early treatment of gastric cancer by endoscopic and/or surgical therapy may decrease mortality; yet reliable, universally applicable biomarkers for early detection of gastric cancer have still not been established.

MATERIALS AND METHODS

The present work compares the expression of CD133 (prominin-1), a potential biomarker of disease progression in gastric cancer, between independent cohorts of H. pylori (+) and H. pylori (-) patients at each respective stage of carcinogenesis. H. pylori (-) patients (N=45) who underwent gastric biopsy at the Moffitt Cancer Center (MCC) in Tampa, Florida, and H. pylori (+) patients (N=59) who underwent gastric biopsy at the Instituto de Patologia Mejia Jimenez (IPMJ) in Cali, Colombia were evaluated and immunostained for CD133.

RESULTS

A statistically significant increase in CD133 expression (in terms of the Allred score) was observed between all stages of progression (normal mucosa, inflammation/metaplasia, low-grade dysplasia and gastric adenocarcinoma) for each respective patient cohort. No statistically significant difference in CD133 expression at each respective stage of disease was observed between the H. pylori-positive and negative-cohorts.

CONCLUSION

The observation of distinct stepwise increases in CD133 expression in both patient cohorts, and the lack of any significant difference between groups, suggests that CD133 expression may serve as a biomarker for early detection of gastric cancer independent of bacterial status and strain, and corresponding differences in disease histomorphology and classification. This warrants further validation on larger independent cohorts across multiple geographic regions and incorporating multiple bacterial strain types.

Helicobacter pylori in human health and disease: Mechanisms for local gastric and systemic effects

Helicobacter pylori (H. pylori) is present in roughly 50% of the human population worldwide and infection levels reach over 70% in developing countries. The infection has classically been associated with different gastro-intestinal diseases, but also with extra gastric diseases. Despite such associations, the bacterium frequently persists in the human host without inducing disease, and it has been suggested that H. pylori may also play a beneficial role in health. To understand how H. pylori can produce such diverse effects in the human host, several studies have focused on understanding the local and systemic effects triggered by this bacterium. One of the main mechanisms by which H. pylori is thought to damage the host is by inducing local and systemic inflammation. However, more recently, studies are beginning to focus on the effects of H. pylori and its metabolism on the gastric and intestinal microbiome. The objective of this review is to discuss how H. pylori has co-evolved with humans, how H. pylori presence is associated with positive and negative effects in human health and how inflammation and/or changes in the microbiome are associated with the observed outcomes.

A Genetic Variant Located in miR-146b Promoter Region Is Associated with Prognosis of Gastric Cancer

Background: SNPs in the promoter region of miRNAs have been reported to be associated with cancer prognosis. Our previous study found that miR-146b had a strong correlation with the stage classification of gastric cancer and contributed to tumor progression. The current study was aimed at investigating whether an SNP located in the promoter region of miR-146b could affect the survival rate of gastric cancer.Methods: Using bioinformatics tools, we identified one SNP (rs1536309) that is located in the miR-146b promoter. We genotyped this SNP site to assess its association with gastric cancer prognosis in 940 cases.Results: We found that the dominant model of miR-146b rs1536309 was associated with a higher survival rate of gastric cancer. The association remained significant in the subgroup analysis by age (≤60), sex (male), tumor size (≤5 cm), histologic type (diffuse), lymph node metastasis (N0), distant metastasis (M0), and TNM stage (I/II).Conclusions: Our results suggested that the miR-146b rs1536309 polymorphism may be a potential biomarker for the prognosis of gastric cancer.Impact: This is the first evidence showing that patients carrying the miR-146b-5p rs1536309 CC/CT genotypes exhibited better survival than those carrying the TT genotype, suggesting the protective effect of the C allele in the prognosis of gastric cancer. Cancer Epidemiol Biomarkers Prev; 27(7); 822-8. ©2018 AACR.

Gastric cancer in Latin America

Every year, cancer affects more than one million Latin Americans. The increasing incidence of cancer could be secondary to an aging population, westernization of life style, and urbanization. LA has among the highest incidence rates of gastric cancer, compared to other countries. In this review, different studies on gastric cancer and its relation with risks factors, such as infections, diet and life styles typical of LA, besides the different molecular alterations of that specific population (mainly at a genetic polymorphism level) are analyzed. An exhaustive research was made in PubMed, MEDLINE and Embase of the most relevant studies conducted in the last 27 years (1990-2017) in LA.

Chalcogen-containing phenolics as antiproliferative agents

Aim: The increasing number of cancer cases has stimulated researchers to seek for novel approaches. We have combined two bioactive moieties: a polyphenolic scaffold and an organoselenium motif. Four different families (isothiocyanates/thioureas, and their selenium isosters) derived from dopamine, (±)-norepinephrine and R-epinephrine were accessed. Results: Heterocumulenes derived from dopamine and β-O-methylnoradrenaline were strong antiproliferative agents (GI50<10 μM). Selenoureas derived from β-O-methylnoradrenaline bearing electron-withdrawing groups (halogen, -NO2, -Ph) on the phenyl ring, were also strong antiproliferative agents, besides exhibiting good antiradical and glutathione peroxidase-like activities. Up to a 14-fold increased activity was achieved compared with classical chemotherapeutic agents, exhibiting also different mechanisms of action (cell cycle assays). Redox analysis on HeLa cells suggested an increase of ROS levels after the incubation period. Conclusion: the combination of organoselenium and phenolic moieties might provide valuable lead compounds with relevant antiproliferative properties.