Gastrin, inflammation, and carcinogenesis

Aberrant Methylation of Somatostatin Receptor 2 Gene Is Initiated in Aged Gastric Mucosa Infected with Helicobacter pylori and Consequential Gene Silencing Is Associated with Establishment of Inflammatory Microenvironment In Vitro Study

The loss-of-function variants are thought to be associated with inflammation in the stomach. We here aimed to evaluate the extent and role of methylation at the SSTR2 promoter in inflammation and gastric tumor formation. A whole-genome bisulfite sequencing analysis revealed that the SSTR2 promoter was significantly hypermethylated in gastric tumors, dysplasia, and intestinal metaplasia compared to non-tumor tissues from patients with gastric cancer. Using public data, we confirmed SSTR2 promoter methylation in primary gastric tumors and intestinal metaplasia, and even aged gastric mucosae infected with Helicobacter pylori, suggesting that aberrant methylation is initiated in normal gastric mucosa. The loss-of-function of SSTR2 in SNU638 cell-induced cell proliferation in vitro, while stable transfection of SSTR2 in AGS and MKN74 cells inhibited cell proliferation and tumorigenesis in vitro and in vivo. As revealed by a comparison of target genes differentially expressed in these cells with hallmark molecular signatures, inflammation-related pathways were distinctly induced in SSTR2-KO SNU638 cell. By contrast, inflammation-related pathways were inhibited in AGS and MKN74 cells ectopically expressing SSTR2. Collectively, we propose that SSTR2 silencing upon promoter methylation is initiated in aged gastric mucosae infected with H. pylori and promotes the establishment of an inflammatory microenvironment via the intrinsic pathway. These findings provide novel insights into the initiation of gastric carcinogenesis.

Constitutive programmed death ligand 1 expression protects gastric G-cells from Helicobacter pylori-induced inflammation

INTRODUCTION

Gastric intestinal metaplasia (GIM) is a premalignant lesion, highly associated with Helicobacter pylori infection. Previous studies have shown that H. pylori is able to induce the expression of programmed death ligand 1 (PD-L1), an inhibitory immune modulator, in gastric cells. Our aim was to investigate whether tissues from GIM patients may exploit PD-L1 expression upon H. pylori infection to evade immunosurveillance.

METHODS

Immunohistochemistry was performed for PD-L1 and enteroendocrine markers somatostatin and gastrin on samples derived from a cohort of patients with known GIM, both before and after H. pylori eradication. To determine the identity of any observed PD-L1-positive cells, we performed multiplex immunofluorescent staining and analysis of single-cell sequencing data.

RESULTS

GIM tissue was rarely positive for PD-L1. In normal glands from GIM patients, PD-L1 was mainly expressed by gastrin-positive G-cells. While the D-cell and G-cell compartments were both diminished 2-fold (p = .015 and p = .01, respectively) during H. pylori infection in the normal antral tissue of GIM patients, they were restored 1 year after eradication. The total number of PD-L1-positive cells was not affected by H. pylori, but the percentage of PD-L1-positive G-cells was 30% higher in infected subjects (p = .011), suggesting that these cells are preferentially rescued from destruction.

CONCLUSIONS

Antral G-cells frequently express PD-L1 during homeostasis. G-cells seem to be protected from H. pylori-induced immune destruction by PD-L1 expression. GIM itself does not express PD-L1 and is unlikely to escape immunosurveillance via expression of PD-L1.

GFAP-directed Inactivation of Men1 Exploits Glial Cell Plasticity in Favor of Neuroendocrine Reprogramming

BACKGROUND & AIMS

Efforts to characterize the signaling mechanisms that underlie gastroenteropancreatic neoplasms (GEP-NENs) are precluded by a lack of comprehensive models that recapitulate pathogenesis. Investigation into a potential cell-of-origin for gastrin-secreting NENs revealed a non-cell autonomous role for loss of menin in neuroendocrine cell specification, resulting in an induction of gastrin in enteric glia. Here, we investigated the hypothesis that cell autonomous Men1 inactivation in glial fibrillary acidic protein (GFAP)-expressing cells induced neuroendocrine differentiation and tumorigenesis.

METHODS

Transgenic GFAP^ΔMen1 mice were generated by conditional GFAP-directed Men1 deletion in GFAP-expressing cells. Cre specificity was confirmed using a tdTomato reporter. GFAP^ΔMen1 mice were evaluated for GEP-NEN development and neuroendocrine cell hyperplasia. Small interfering RNA-mediated Men1 silencing in a rat enteric glial cell line was performed in parallel.

RESULTS

GFAP^ΔMen1 mice developed pancreatic NENs, in addition to pituitary prolactinomas that phenocopied the human MEN1 syndrome. GFAP^ΔMen1 mice exhibited gastric neuroendocrine hyperplasia that coincided with a significant loss of GFAP expression. Men1 deletion induced loss of glial-restricted progenitor lineage markers and an increase in neuroendocrine genes, suggesting a reprogramming of GFAP⁺ cells. Deleting Kif3a, a mediator of Hedgehog signaling, in GFAP-expressing cells attenuated neuroendocrine hyperplasia by restricting the neuroendocrine cell fate. Similar results in the pancreas were observed when Sox10 was used to delete Men1.

CONCLUSIONS

GFAP-directed Men1 inactivation exploits glial cell plasticity in favor of neuroendocrine differentiation.

Pancreas and Adverse Drug Reactions: A Literature Review

Adverse drug reactions (ADRs) affecting the pancreas are a heterogeneous group of side effects that cause damage to pancreatic cells. Various mechanisms such as hypersensitization, sphincter of Oddi constriction, direct cytotoxic and metabolic effects on pancreatic cells, and dose-dependent idiosyncrasy lead to intrapancreatic activation of pancreatic enzymes resulting in drug-induced acute pancreatitis. Several medications have been linked with the development of pancreatic cancer. Pancreatic cancer may result from proinflammatory, proliferative, and antiapoptotic effects. Diabetogenic effect of drugs, which is understood as impairment of insulin secretion, may occur due to direct destruction of β cells, systemic toxicity affecting pancreatic islets and cell membrane glucose transporters, induction of Th1-type autoimmune response, and impairment of voltage-gated calcium channels in β cells, endoplasmic reticulum stress, and insulin signaling. A better understanding of ADRs that affect the pancreas may contribute to improving the awareness of clinicians and patients and reducing potential harmful side effects of implemented therapies.

Metabolic Hormones Modulate Macrophage Inflammatory Responses

Simple Summary

Macrophages are a type of immune cell which play an important role in the development of cancer. Obesity increases the risk of cancer and obesity also causes disruption to the normal levels of hormones that are produced to coordinate metabolism. Recent research now shows that these metabolic hormones also play important roles in macrophage immune responses and so through macrophages, disrupted metabolic hormone levels may promote cancer. This review article aims to highlight and summarise these recent findings so that the scientific community may better understand how important this new area of research is, and how these findings can be capitalised on for future scientific studies.

Abstract

Macrophages are phagocytotic leukocytes that play an important role in the innate immune response and have established roles in metabolic diseases and cancer progression. Increased adiposity in obese individuals leads to dysregulation of many hormones including those whose functions are to coordinate metabolism. Recent evidence suggests additional roles of these metabolic hormones in modulating macrophage inflammatory responses. In this review, we highlight key metabolic hormones and summarise their influence on the inflammatory response of macrophages and consider how, in turn, these hormones may influence the development of different cancer types through the modulation of macrophage functions.

Does the Use of Proton Pump Inhibitors Increase the Risk of Pancreatic Cancer? A Systematic Review and Meta-Analysis of Epidemiologic Studies

Background: One of the most frequently used medications for treating gastrointestinal disorders is proton pump inhibitor (PPI), which reportedly has potential adverse effects. Although the relationship between the use of PPIs and the risk of pancreatic cancer has been extensively investigated, the results remain inconsistent. Hence, this meta-analysis aimed to evaluate such relationship. Methods: We searched for literature and subsequently included 10 studies (seven case–control and three cohort studies; 948,782 individuals). The pooled odds ratio (OR) and 95% confidence intervals (CI) for pancreatic cancer were estimated using a random-effects model. We also conducted sensitivity analysis and subgroup analysis. Results: The pooled OR of the meta-analysis was 1.698 (95% CI: 1.200–2.402, p = 0.003), with a substantial heterogeneity (I² = 98.75%, p < 0.001). Even when studies were excluded one by one, the pooled OR remained statistically significant. According to the stratified subgroup analyses, PPI use, and pancreatic cancer incidence were positively associated, regardless of the study design, quality of study, country, and PPI type. Conclusion: PPI use may be associated with the increased risk of pancreatic cancer. Hence, caution is needed when using PPIs among patients with a high risk of pancreatic cancer.

Association of Helicobacter pylori infection with colorectal polyps and malignancy in China

BACKGROUND

Gastric Helicobacter pylori (H. pylori) infection is related to chronic gastritis, gastroduodenal ulcer, and gastric malignancies; whether this infection is related to colorectal polyps and colorectal cancer (CRC), remains debatable.

AIM

To investigate the relationship between gastric H. pylori infection and the risk of colorectal polyps and CRC.

METHODS

We retrospectively analyzed 3872 patients with colorectal polyps who underwent colonoscopy and pathological diagnosis. We also analyzed 304 patients with primary CRC. The characteristics of these patients were compared with those of the control group, which included 2362 patients with the normal intestinal mucosa. All subjects completed a ¹⁴C-urea breath test, bidirectional gastrointestinal endoscopy, and a biopsy on the same day. Data on the number, size, location, and pathology of the polyps, the location, and pathology of the CRC, the detection of H. pylori, and the incidence of H. pylori-associated atrophic gastritis or intestinal metaplasia were obtained. A logistic regression model was used to analyze the relationship between gastric infection due to H. pylori, and the incidence of colorectal polyps and CRC.

RESULTS

The prevalence of H. pylori infection was higher in the multiple polyps group than in the solitary polyp group and the control group [95% confidence interval (CI) = 1.02-1.31, P = 0.03; 95%CI: 2.12-2.74, P < 0.001]. The patients with adenomatous polyps had a higher incidence of H. pylori infection than patients with non-adenomatous polyps [59.95% vs 51.75%, adjusted odds ratio (OR) = 1.41, 95%CI: 1.24-1.60, P < 0.01]. Patients with H. pylori-associated atrophic gastritis or intestinal metaplasia were at high risk of CRC (adjusted OR = 3.46, 95%CI: 2.63-4.55, P < 0.01; adjusted OR = 4.86, 95%CI: 3.22-7.34, P < 0.01, respectively). The size and location of the polyps, the histopathological characteristics and the location of CRC were not related to H. pylori infection.

CONCLUSION

Our study demonstrates that the incidence of gastric H. pylori infection and H. pylori-associated atrophic gastritis or intestinal metaplasia elevates the risk of colorectal polyps and CRC.

Association Between Acid-Suppressive Agents’ Use and Risk of Hepatocellular Carcinoma

Background:

Acid-suppressive agents (ASAs), which are mostly used in patients with upper gastrointestinal diseases (UGIDs), may influence the risk of hepatocellular carcinoma (HCC).

Methods:

A population-based retrospective cohort study was conducted. Patients with UGID who used ASAs and those who did not receive ASAs were identified. Patients without UGIDs were randomly selected and matched (comparison group). All groups were followed up for 6 years. A Cox proportional hazard model was used to estimate the risk of HCC among the different groups.

Results:

Patients with UGID who used ASAs had a significantly elevated HCC risk (adjusted hazard ratio [HR] 1.53; 95% confidence interval [CI], 1.32-1.76] compared to those who did not use ASAs. Patients with UGID who used more than 540 defined daily doses of ASAs had a significantly higher risk of HCC (adjusted HR 2.04; 95% CI, 1.62-2.58). Moreover, the dose effect on HCC risk exhibited a significant increasing trend ( P < .01). Furthermore, patients with UGID who did not use ASAs had a significantly elevated HCC risk (adjusted HR 1.94; 95% CI, 1.59-2.36) compared to the comparison group.

Conclusion:

The use of ASAs increased the risk of HCC in patients with UGIDs, and the effect of ASAs was dose dependent. In addition, UGIDs alone increased the risk of HCC.

Activation of a nerve injury transcriptional signature in airway-innervating sensory neurons after lipopolysaccharide-induced lung inflammation

The lungs and the immune and nervous systems functionally interact to respond to respiratory environmental exposures and infections. The lungs are innervated by vagal sensory neurons of the jugular and nodose ganglia, fused together in smaller mammals as the jugular-nodose complex (JNC). Whereas the JNC shares properties with the other sensory ganglia, the trigeminal (TG) and dorsal root ganglia (DRG), these sensory structures express differential sets of genes that reflect their unique functionalities. Here, we used RNA sequencing (RNA-seq) in mice to identify the differential transcriptomes of the three sensory ganglia types. Using a fluorescent retrograde tracer and fluorescence-activated cell sorting, we isolated a defined population of airway-innervating JNC neurons and determined their differential transcriptional map after pulmonary exposure to lipopolysaccharide (LPS), a major mediator of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) after infection with gram-negative bacteria or inhalation of organic dust. JNC neurons activated an injury response program, leading to increased expression of gene products such as the G protein-coupled receptor Cckbr, inducing functional changes in neuronal sensitivity to peptides, and Gpr151, also rapidly induced upon neuropathic nerve injury in pain models. Unique JNC-specific transcripts, present at only minimal levels in TG, DRG, and other organs, were identified. These included TMC3, encoding for a putative mechanosensor, and urotensin 2B, a hypertensive peptide. These findings highlight the unique properties of the JNC and reveal that ALI/ARDS rapidly induces a nerve injury-related state, changing vagal excitability.

Proton pump inhibitors and histamine-2 receptor antagonists on the risk of pancreatic cancer: a systematic review and meta-analysis

BACKGROUND

Proton pump inhibitors (PPI) and histamine-2 receptor antagonists (H2RA) have been widely used for multiple purposes. Recent studies have suggested an association between these medications and the risk of pancreatic cancer. However, the results have been inconclusive.

AIM

We, therefore, conducted a study to assess the risk of developing pancreatic cancer in patients who used PPI and H2RA.

DESIGN

A systematic review and meta-analysis.

METHODS

A literature search was performed using MEDLINE and EMBASE databases from inception through February 2019. Studies that reported risk ratio comparing the risk of pancreatic cancer in patients who received PPI or H2RA versus those who did not receive treatments were included. Pooled risk ratios (RR) and 95% confidence intervals (CI) were calculated using a random-effect generic inverse variance method. Sensitivity analysis, excluding one study at a time, was performed.

RESULTS

After screening abstracts from the searching methods, seven studies (six case-control studies and one cohort study) were included in the analysis with total 546 199 participants. Compared to patients who did not take medications, the pooled RR of developing pancreatic cancer in patients receiving PPI and H2RA were 1.73 (95% CI: 1.16-2.57) and 1.26 (95% CI: 1.02-1.57), respectively. However, the sensitivity analysis of PPI changed the pooled RR to 1.87 (95% CI: 1.00-3.51) after a study was dropped out. Likewise, H2RA sensitivity analysis also resulted in non-significant pooled RR.

CONCLUSIONS

This meta-analysis did not find the strong evidence for the associations between the use of PPI and H2RA and pancreatic cancer.

Changes in plasma levels of cholecystokinin, neurotensin, VIP and PYY in gastric and colorectal cancer - Preliminary results

Physiological roles of enterohormones such as secretion, absorption and digestion were supported by clinical data. Overexpression of cholecystokinin (CCK), neurotensin (NT) and vasoactive intestinal peptide (VIP) receptors occur in gastrointestinal (GI) malignancies. The aim of the paper was to compare plasma levels of CCK, peptide YY (PYY), VIP and NT in patients with gastrointestinal malignancies and healthy controls. The study included 80 patients (37 men and 43 women) with GI malignancies (20 with gastric and 60 with colorectal cancers). Median age of the patients was 62.9 years (range: 40-85 years). Control group was comprised of 30 healthy persons with median age 59.8 years (range: 40-82 years). Fasting plasma concentrations of CKK, PYY, NT, and VIP were determined at rest, using ELISA kits for automated systems. Comparative analysis of enterohormone levels in patients with various types of gastrointestinal malignancies demonstrated presence of some cancer-specific alterations. Patients with gastric cancers presented with lower plasma concentrations of CCK than healthy controls and individuals from colorectal cancers (p = 0.02). The highest plasma concentrations of neurotensin was found in colorectal cancer patients in comparison to gastric (p = 0.02). The plasma levels of VIP observed in gastric cancer group were lower than in colorectal cancer patients (p = 0.01). Patients with GI malignancies may present with tumor-specific alterations in plasma enterohormone levels.

Clinical significance of serum markers reflecting gastric function and H. pylori infection in colorectal cancer

Purpose: The study was conducted to investigate the relationship of serum pepsinogens PGI, PGII, gastrin-17, and Hp-IgG with colorectal cancer (CRC), aiming to explore the clinical significance of serum markers reflecting gastric function and H. pylori infection in CRC. Methods: A total of 569 CRC cases and 569 age and sex-matched controls were enrolled in this study between June 2012 and April 2016 from The First Hospital of China Medical University. The serum markers reflecting gastric function and H. pylori infection were detected using ELISA, including PGI, PGII, PGI/II ratio, G-17 and Hp-IgG. Information of clinicopathological parameters and tumor biomarkers was collected from the medical records of inpatients, including CEA, CA199, CA125, CA153 and AFP. Results: Serum PGII, G-17 levels and Hp-IgG were increased in CRC, while PGI and PGI/II ratio appeared no significant difference between CRC and controls. In subgroup analysis, PGII was more significant in males (P=0.014). Hp-IgG was demonstrated higher in age<60y (P=0.001). With respect to the association with serum tumor biomarkers, G-17 level was associated with the rise of CA125 (P=0.005, OR (95%CI): 4.89 (1.90-12.57)), Hp-IgG increasing was associated with the rise of CA125 (P=0.024, OR (95%CI): 4.10 (1.54-10.93)). Conclusions: Serum PGII, G-17 and Hp-IgG were associated with CRC risk. The serum levels of G-17 and Hp-IgG were associated with the rise of CA125 in patients with CRC.

Association Between Cholangiocarcinoma and Proton Pump Inhibitors Use: A Nested Case-Control Study

Background: The present study aimed to examine the odds of cholangiocarcinoma (CCA) in patients with proton pump inhibitors (PPIs) use. Methods: A nested case-control study design was employed using data obtained from Taiwan's National Health Insurance Research Database. In total, 2,293 patients with confirmed diagnosis of CCA were identified and served as the CCA group. The CCA patients were propensity score-matched with 2,293 subjects without CCA who served as the control group. The cumulative defined daily dose (DDD) of PPIs was calculated based on the total supply in days and quantity of individual PPIs. Univariable and multivariate logistic regression models were used to determine the odds of CCA, and calculated odds ratios (ORs) and 95% confidence intervals (CI) were used to assess PPIs use and odds of CCA. Results: The overall adjusted OR of PPIs use-associated CCA was 2.58 (95% CI 2.27, 2.93). The adjusted OR of CCA by cumulative DDD dose of PPIs and CCA was analyzed and revealed those odds of CCA are associated with all types of PPIs. Conclusions: There were odds of intrahepatic and extrahepatic CCA among PPIs users. All PPIs use was associated with odds of CCA. Analyses of larger numbers of cases are needed to confirm these findings.

The prognostic value of neutrophil to lymphocyte and platelet to lymphocyte ratios for patients with lung cancer

As the leading cause of cancer-associated mortality globally among males in 2012, lung cancer is a disease of particular concern. Previously, the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR) were revealed to be prognostic factors for various types of cancer, including lung cancer. In the present study, a retrospective review was conducted with patients who were diagnosed with lung cancer between January 1, 2000 and December 31, 2005 in the Fourth Hospital of Hebei Medical University. A total of 695 patients were included, and the optimal cutoffs of the NLR and the PLR were 6.0 and 248.0, respectively. There were statistically significant associations between tumor-node-metastasis (TNM) stage, surgery, metastasis incidence and NLR (P<0.001). The associations between TNM stage, surgery incidence and PLR were also revealed to be statistically significant (P<0.001). Patients in the low NLR group demonstrated longer overall survival (OS) than patients in the high NLR group (819.57 days vs. 629.86 days, P=0.041). The NLR at diagnosis was demonstrated to be an independent prognostic factor for OS. Thus, the NLR may be a promising approach for predicting the prognosis of patients with lung cancer.

Insights into gastric neuroendocrine tumors burden

Type 1 gastric neuroendocrine tumors (gNETs) are usually small lesions, restricted to mucosal and sub-mucosal layers of corpus and fundus, with low aggressive behavior, for the majority of cases. Nevertheless, some cases present aggressive behavior. The increasing incidence of gNETs brings together a new relevant problem: how to identify potentially aggressive type 1 gNETs. The challenging problem seems to be finding out signs or features able to predict potentially aggressive cases, allowing a tailored approach, since the involved societies dedicated to provide guidelines for management of these neoplasms apparently failed in producing staging systems able to accurately predict prognosis of these tumors. Additionally, it is also important to try to find out explanations for increasing incidence, as well as to identify potential targets aiming to reach better control of this neoplasia. Here, we discuss potential pathways implicated in aggressive behavior, as well as new strategies to improve clinical management of these tumors.

Exploratory Factor Analysis for Validating Traditional Chinese Syndrome Patterns of Chronic Atrophic Gastritis

Background. Traditional Chinese medicine (TCM) has long been used to treat chronic atrophic gastritis (CAG). The aim of the present study was to evaluate the TCM syndrome characteristics of CAG and its core pathogenesis so as to promote optimization of treatment strategies. Methods. This study was based on a participant survey conducted in 4 hospitals in China. Patients diagnosed with CAG were recruited by simple random sampling. Exploratory factor analysis (EFA) was conducted on syndrome extraction. Results. Common factors extracted were assigned to six syndrome patterns: qi deficiency, qi stagnation, blood stasis, phlegm turbidity, heat, and yang deficiency. Distribution frequency of all syndrome patterns showed that qi deficiency, qi stagnation, blood stasis, phlegm turbidity, and heat excess were higher (76.7%-84.2%) compared with yang deficiency (42.5%). Distribution of main syndrome patterns showed that frequencies of qi deficiency, qi stagnation, phlegm turbidity, heat, and yang deficiency were higher (15.8%-20.8%) compared with blood stasis (8.3%). Conclusions. The core pathogenesis of CAG is combination of qi deficiency, qi stagnation, blood stasis, phlegm turbidity, heat, and yang deficiency. Therefore, treatment strategy of herbal prescriptions for CAG should include herbs that regulate qi, activate blood, resolve turbidity, clear heat, remove toxin, and warm yang.

Trastuzumab Inhibits Growth of HER2-Negative Gastric Cancer Cells Through Gastrin-Initialized CCKBR Signaling

BACKGROUND

Administration of trastuzumab, a fully humanized monoclonal antibody targeted to the human epidermal growth factor receptor 2 (HER2, p185), has improved outcomes for patients with HER2-positive gastric cancer (GC), but some relevant issues remain to be investigated and will emerge with new anti-GC drugs. Gastrin is a major gastrointestinal hormone proven to have an inhibitory effect on GC in vitro and in vivo.

AIM

To explore the sympathetic role of trastuzumab and gastrin on inhibition of GC.

METHODS

The HER2-positive and HER2-negative GC cell lines were treated with trastuzumab, gastrin, or their combination in vitro and in xenograft model. The synergistical role of trastuzumab and gastrin and related mechanisms were investigated.

RESULTS

We found the synergistic inhibitory effects of trastuzumab and gastrin on HER2-negative GC cells through the gastrin/cholecystokinin B receptor (CCKBR) pathway. Trastuzumab upregulated CCKBR protein levels but could not initiate its signal transduction, whereas gastrin increased the levels and activation of CCKBR. Molecular experiments indicated that trastuzumab and gastrin co-treatment synergistically enhanced the stability of CCKBR. Moreover, their combined treatment synergistically arrested GC cells at G0/G1 phase, down-regulated levels of GC-related proteins, including anion exchanger 1 (AE1), cyclin D1, β-catenin, and cytoplasmic p16, and promoted nuclear translocation of p16. In addition, combination treatment upregulated AE2 levels, which are reduced in GC tissues. The in vivo synergistic anti-GC effect of combined treatment was confirmed in xenograft experiments.

CONCLUSIONS

Trastuzumab plus gastrin inhibit growth of Her2-negative GC by targeting cytoplasmic AE1 and p16.

Helicobacter pylori infection, gastrin and cyclooxygenase-2 in gastric carcinogenesis

Gastric cancer is one of the most frequent neoplasms and a main cause of death worldwide, especially in China and Japan. Numerous epidemiological, animal and experimental studies support a positive association between chronic Helicobacter pylori (H. pylori) infection and the development of gastric cancer. However, the exact mechanism whereby H. pylori causes gastric carcinogenesis remains unclear. It has been demonstrated that expression of cyclooxygenase-2 (COX-2) is elevated in gastric carcinomas and in their precursor lesions. In this review, we present the latest clinical and experimental evidence showing the role of gastrin and COX-2 in H. pylori-infected patients and their possible association with gastric cancer risk.

The relationship between Helicobacter pylori and cancer risk

OBJECTIVES

This study investigated the correlation between Helicobacter pylori (HP) and cancer risk. We compared the age, sex, and comorbidity of cancer patients both infected and not infected by HP.

METHODS

In this study, we compared a comparison cohort (N=24,088) and an HP cohort (N=6022), both taken from the NHI database. We performed a statistical analysis with the multivariable Cox proportional model to estimate the risk of developing cancer for a comparison and the HP cohort.

RESULTS

Our results showed that the proportion of peptic ulcers in the HP cohort was nearly 4 times higher than that in the comparison cohort. The HP cohort was significantly associated with increased colorectal (HR=1.73, 95% CI=1.08-2.77), stomach (HR=5.21, 95% CI=2.46-11.05) and pancreatic (HR=2.77, 95% CI=1.04-7.39) cancer risks compared to the comparison cohort. In addition, the cancer risk in the HP cohort was considerably higher than that in the comparison cohort when hypertension was absent in both cohorts.

CONCLUSIONS

In this study, we proposed a method to investigate the correlation between HP infection and cancer risk. We found that HP infection is associated with the development of colorectal, stomach, and pancreatic cancers, and could thus be an independent carcinogenic risk factor.

The duration of gastrin treatment affects global gene expression and molecular responses involved in ER stress and anti-apoptosis

Background

How cells decipher the duration of an external signal into different transcriptional outcomes is poorly understood. The hormone gastrin can promote a variety of cellular responses including proliferation, differentiation, migration and anti-apoptosis. While gastrin in normal concentrations has important physiological functions in the gastrointestine, prolonged high levels of gastrin (hypergastrinemia) is related to pathophysiological processes.

Results

We have used genome-wide microarray time series analysis and molecular studies to identify genes that are affected by the duration of gastrin treatment in adenocarcinoma cells. Among 403 genes differentially regulated in transiently (gastrin removed after 1 h) versus sustained (gastrin present for 14 h) treated cells, 259 genes upregulated by sustained gastrin treatment compared to untreated controls were expressed at lower levels in the transient mode. The difference was subtle for early genes like Junb and c-Fos, but substantial for delayed and late genes. Inhibition of protein synthesis by cycloheximide was used to distinguish between primary and secondary gastrin regulated genes. The majority of gastrin upregulated genes lower expressed in transiently treated cells were primary genes induced independently of de novo protein synthesis. This indicates that the duration effect of gastrin treatment is mainly mediated via post-translational signalling events, while a smaller fraction of the differentially expressed genes are regulated downstream of primary transcriptional events. Indeed, sustained gastrin treatment specifically induced prolonged ERK1/2 activation and elevated levels of the AP-1 subunit protein JUNB. Enrichment analyses of the differentially expressed genes suggested that endoplasmic reticulum (ER) stress and survival is affected by the duration of gastrin treatment. Sustained treatment exerted an anti-apoptotic effect on serum starvation-induced apoptosis via a PKC-dependent mechanism. In accordance with this, only sustained treatment induced anti-apoptotic genes like Clu, Selm and Mcl1, while the pro-apoptotic gene Casp2 was more highly expressed in transiently treated cells. Knockdown studies showed that JUNB is involved in sustained gastrin induced expression of the UPR/ER stress related genes Atf4, Herpud1 and Chac1.

Conclusion

The duration of gastrin treatment affects both intracellular signalling mechanisms and gene expression, and ERK1/2 and AP-1 seem to play a role in converting different durations of gastrin treatment into distinct cellular responses.

Gastrin receptor pharmacology

C-terminally amidated gastrins act at cholecystokinin-2 receptors (CCK2R), which are normally expressed by gastric parietal and enterochromaffin-like (ECL) cells and smooth muscle; there is also extensive expression in the CNS where the main endogenous ligand is cholecystokinin. A variety of neoplasms express CCK2R, or splice variants, including neuroendocrine, pancreatic, medullary thyroid and lung cancers. Other products of the gastrin gene (progastrin, the Gly-gastrins) may stimulate cell proliferation but are not CCK2R ligands. Depending on the cell type, stimulation of CCK2R evokes secretion, increases proliferation and cell migration, inhibits apoptosis, and controls the expression of various genes. These effects are mediated by increased intracellular calcium and activation of protein kinase C, MAPkinase and other protein kinase cascades. There has been recent progress in developing CCK2R ligands that can be used for imaging tumours expressing the receptor. New antagonists have also been developed, and there is scope for using these for suppression of gastric acid and for treatment of neuroendocrine and other CCK2R-expressing tumours.

Promoting role of cholecystokinin 2 receptor (CCK2R) in gastrointestinal stromal tumour pathogenesis

The cholecystokinin 2 receptor (CCK2R/CCKBR) is expressed in gastrointestinal stromal tumours (GISTs). We sought to investigate the role of CCK2R in GIST pathogenesis. Molecular characterization of CCK2R was performed on a heterogeneous cohort of 50 GISTs. In addition, CCK2R expression was evaluated by immunohistochemistry (IHC), using tissue microarray (TMA) containing 292 GISTs, two cases of hyperplasia of interstitial Cajal's cells (ICC) and six gastric microscopic GISTs. Mono-allelic loss of the CCK2R/11p15 allele was identified in 13.7% of GISTs, having no impact on the level of CCK2R transcript expression. No CCK2R mutations were found. The CCK2Ri4sv, CCK2R splice variant with retention of intron 4 was detected in six of 20 tumours analysed. Wild-type CCK2R transcripts were commonly expressed (57.1% of cases) and this expression was highly correlated with gastric primary site of GISTs (p < 0.001). At the protein level, expression of CCK2R in incidental ICC hyperplasia and early stages of gastric GIST development was documented, and its gastric association was confirmed on GIST-TMA by IHC. To explore the in vivo effect of CCK2R activation on tumour growth, gastrin versus placebo was administered intraperitoneally in nude mice carrying human GIST xenografts. The tumour volume was followed for 10 weeks. The effect of this stimulation on tumour cell proliferation/apoptosis was assessed by IHC and KIT/PKC-θ signalling was evaluated by western blotting (WB). In vivo experiments showed a two-fold increase in the volume of tumours which were exposed to gastrin in comparison with non-exposed controls (p = 0.03), with a significant increase in mitotic activity (p = 0.04) and Ki-67 proliferation index (p = 0.008). By WB, gastrin stimulation resulted in hyper-activation of KIT and PKC-θ kinases, and in evident PI3K-AKT pathway over-activation. Our results indicate a promoting role of CCK2R on GIST tumourigenesis, particularly in tumours of gastric origin.

High-expression of ZBP-89 correlates with distal metastasis and poor prognosis of patients in clear cell renal cell carcinoma

ZBP-89, a Krüppel-type zinc-finger transcription factor, is found to participate in tumor development, invasion and metastasis. However, the expression status of ZBP-89 in clear cell renal cell carcinoma (CCRCC) remains elusive. Using quantitative real-time-PCR and Western Blot, we found that, in fresh cancer tissues, ZBP-89 was remarkably decreased in 79.2% (19/24) and 83.3% (5/6) of CCRCC at mRNA and protein level, respectively. Immunohistochemistry also revealed a significant decline of ZBP-89 expression in CCRCC, showing that low expression of ZBP-89 was present in 73.9% (105/142) of tumorous tissues but in 48.1% (52/108) of the corresponding adjacent kidney tissues. Furthermore, ZBP-89 expression in CCRCC was significantly correlated with several clinicopathological features, including TNM stage (P=0.005) and distal metastasis (P=0.001). Further study confirmed that ZBP-89 expression was markedly higher in metastatic CCRCC than that in non-metastatic tissue (P=0.002). In addition, CCRCC patients with low ZBP-89 expression survived longer than those with high ZBP-89 expression, as indicated by the result of univariate analysis (P<0.0001). More importantly, multivariate analysis revealed that ZBP-89 was an independent predictor of overall survival (HR, 2.871; 95% CI, 1.409-5.853; P=0.004). Collectively, our study provides vigorous evidence that ZBP-89 was significantly downregulated in CCRCC and could be served as a promising biomarker for prediction of distal metastasis and prognosis of patient with CCRCC.

Correlation of epigenetic aberrance with STAT3 signaling pathway in gastric carcinogenesis

BACKGROUND

It has been suggested that STAT3 signaling plays important roles in regulating epigenetic aberrance during tumorigenesis, especially in the expression of certain key epigenetic enzymes such as DNMTs, HDACs, and HMTs. However, there has been no report on the relationship of STAT3 signaling and epigenetic aberrance in gastrocarcinogenesis.

AIM

The purpose of this study was to explore the interrelationship of STAT3 signaling pathway and epigenetic aberrance in gastrocarcinogenesis.

METHODS

Immunohistochemistry was utilized to examine the protein expressions of pSTAT3, DNMT1, HDAC1, and EZH2 in 153 tissue specimens, including 20 of normal gastric epithelium tissue, 21 of intestinal metaplasia (IM), 24 of dysplasia (DYS), 23 of early gastric cancer (EGC) and 65 of advanced gastric cancer (AGC), and then analyze their possible relationship with clinicopathological factors.

RESULTS

We found that the four protein expressions were obviously enhanced following the malignant process of gastric carcinogenesis. Pearson correlation analysis of all the pathological groups showed that expression of pSTAT3 was highly associated with DNMT1, but not with HADC1 and EZH2. However, significant correlations were detected among the expression of DNMT1, HDAC1, and EZH2. Further analysis of each pathological group demonstrated that pSTAT3's expression was dramatically related with DNTM1 in the IM (P = 0.021) and EGC groups (P = 0.013) and correlated with EZH2 in the DYS group (P = 0.020). Furthermore, pSTAT3's expression was associated with T staging (P = 0.015) in the AGC group, whereas DNMT1 was associated with gender (P = 0.021), HDAC1 with Lauren classification (P = 0.007), and EZH2 with T staging (P = 0.003) and lymphatic staging (P = 0.038).

CONCLUSIONS

The STAT3 signaling pathway may correlate with epigenetic aberrance during gastrocarcinogenesis.

Association of helicobacter pylori infection and colon cancer

BACKGROUND

Gastrin has been shown to exert carcinogenic effect to the epithelium of the colon. This study examines whether hypergastrinemia and H. pylori infection -especially infection by the CagA+ strain- are statistically associated with colorectal cancer and examine possible correlations with the colorectal cancer stage and lymph node metastasis.

METHODS

In this prospective case-control study, fasting serum samples from 93 consecutive patients with colorectal cancer treated in a university surgical clinic were preoperatively collected and serum levels of gastrin were measured. A group of 20 age matched hernia patients were used as controls. The pathology report of the specimens was documented and statistical analysis of the data where performed with the spss 17 statistical suite.

RESULTS

H. pylori IgG antibodies was reported in 66/93 (71%) in the colorectal cancer group and 13/20 patients in the control group (65%), the difference having non-statistical significance (P = n.s). The prevalence of cagA protein expression in the anti- H. pylori IgG+ patients were higher in the colorectal cancer group (56% positivity), when compared to the control group (38,4% positivity) but the difference was not of statistical significance (P = n.s). The mean levels of serum gastrin levels in the two groups did not significantly differ (Ca group 51.1 ± 36.6 pg/mL vs Control 49.8 ± 17.6 P = n.s.). Patients with lymph node metastasis had higher serum gastrin levels than patients without metastasis and this difference was statistically significant. (53.6 vs 41.06 pg/mL P = 0.025).

CONCLUSIONS

Although the serum gastrin levels were not statistically different between the TNM stages of our patient cohort, our data found that serum gastrin levels were significantly higher in patients with lymph node metastasis. Whether gastrin is implicated in the ability of cancer cells to metastasize to the lymph nodes merits further research.

The presence of Helicobacter pylori in colorectal polyps detected by immunohistochemical methods in children

AIM

Polyps are a common cause of hematochezia in children, but the pathogenesis of polyps is unclear. The aim of this study was to investigate the relationship between Helicobacter pylori (HP) infection and colorectal polyps in children.

METHODS

Thirty-five patients who had undergone polypectomy after the detection of polyps served as the case group. Twenty-seven patients with gastrointestinal symptoms and normal colonoscopy served as the control group. Hematoxylin and eosin (HE) stains obtained from paraffin blocks were evaluated and classified according to histopathologic type and degree of dysplasia. The other sections were used to detect HP organisms for immunohistochemistry (IHC). The seroprevalence of HP antibodies in children with colorectal polyps was detected by protein chip technology. HP infection was diagnosed if the serum urease antibody was positive.

RESULTS

The HP-positive rate in children with colorectal polyps was 57.1% (20/35), which was higher than the rate of 22.2% (6/27) for colonic mucosa in the control group (P < 0.01). The differences in the presence and absence of HP infection between patients with juvenile polyps and juvenile polyposis syndrome were not statistically significant. Age, gender, and the number, size, and locations of the colonic polyps were not significantly different between the patients with HP-positive and HP-negative polyps. The HP-antibody-positive rate was 65.0% (13/20) in the patients with HP-infection-positive colorectal polyps, which was higher than the rate of 26.7% (4/15) for the patients with HP-infection-negative colorectal polyps (P < 0.05).

CONCLUSION

Our findings suggest a positive association between HP infection and colorectal polyps in children in this study, indicating that HP infection is a risk factor for colorectal polyps in children.

Proton pump inhibitors and histamine-2-receptor antagonists and pancreatic cancer risk: a nested case-control study

BACKGROUND

The relationship between use of proton pump inhibitors (PPIs) and histamine-2-receptor antagonists (H(2)RAs) and pancreatic cancer risk has yet to be examined. Data from a range of studies suggest biologically plausible mechanisms, whereby these drugs (or the conditions for which they are prescribed) may affect pancreatic cancer risk. The objective of this study was to investigate the relationship between use of PPIs/H(2)RAs and pancreatic cancer risk.

METHODS

A nested case-control study was conducted within the UK general practice research database (GPRD). Cases had a diagnosis of exocrine pancreatic cancer and controls were matched to cases on general practice site, sex and year of birth. Exposure to PPIs and to H(2)RAs since entry into GPRD until 2 years before the diagnosis date (corresponding date in controls) and in the 5 years before the diagnosis date were separately assessed. Conditional logistic regression analyses were used to generate odds ratios (ORs) and 95% confidence intervals (CIs) associated with PPI or H(2)RA use compared with nonuse.

RESULTS

Ever use of PPIs since entry into the GPRD (excluding the 2 years prior to diagnosis) was not associated with risk of pancreatic cancer; OR (95% CI) 1.02 (0.85-1.22). Neither the dose nor the duration of PPI or H(2)RA use was associated with pancreatic cancer risk. No consistent patterns of association were seen when cumulative exposure (dose and duration) to these drugs was examined separately or together.

CONCLUSION

PPI/H(2)RA use, in a UK population, was not associated with pancreatic cancer risk.

The effect of artificial neural network model combined with six tumor markers in auxiliary diagnosis of lung cancer

To evaluate the diagnosis potential of artificial neural network (ANN) model combined with six tumor markers in auxiliary diagnosis of lung cancer, to differentiate lung cancer from lung benign disease, normal control, and gastrointestinal cancers. Serum carcino-embryonic antigen (CEA), gastrin, neurone specific enolase (NSE), sialic acid (SA), Cu/Zn, Ca were measured through different experimental procedures in 117 lung cancer patients, 93 lung benign disease patients, 111 normal control, 47 gastric cancer patients, 50 patients with colon cancer and 50 esophagus cancer patients, 19 parameters of basic information were surveyed among lung cancer, lung benign disease and normal control, then developed and evaluated ANN models to distinguish lung cancer. Using the ANN model with the six serum tumor markers and 19 parameters to distinguish lung cancer from benign lung disease and healthy people, the sensitivity was 98.3%, the specificity was 99.5% and the accuracy was 96.9%. Another three ANN models with the six serum tumor markers were employed to differentiate lung cancer from three gastrointestinal cancers, the sensitivity, specificity and accuracy of distinguishing lung cancer from gastric cancer by the ANN model of lung cancer-gastric cancer were 100%, 83.3% and 93.5%, respectively; The sensitivity, specificity and accuracy of discriminating lung cancer by lung cancer-colon cancer ANN model were 90.0%, 90.0%, and 90.0%; And which were 86.7%, 84.6%, and 86.0%, respectively, by lung cancer-esophagus cancer ANN model. ANN model built with the six serum tumor markers could distinguish lung cancer, not only from lung benign disease and normal people, but also from three common gastrointestinal cancers. And our evidence indicates the ANN model maybe is an excellent and intelligent system to discriminate lung cancer.

Ectopic pregnancy as a model to identify endometrial genes and signaling pathways important in decidualization and regulated by local trophoblast

The endometrium in early pregnancy undergoes decidualization and functional changes induced by local trophoblast, which are not fully understood. We hypothesized that endometrium from tubal ectopic pregnancy (EP) could be interrogated to identify novel genes and pathways involved in these processes. Gestation-matched endometrium was collected from women with EP (n = 11) and intrauterine pregnancies (IUP) (n = 13). RNA was extracted from the tissue. In addition, tissues were prepared for histological analysis for degree of decidualization. We compared a) the samples from EP that were decidualized (n = 6) with non-decidualized samples (n = 5), and b) the decidualized EP (n = 6) with decidualization-matched IUP (n = 6) samples using an Affymetrix gene array platform, with Ingenuity Pathway Analysis, combined with quantitative RT-PCR. Expression of PRL and IGFBP1 was used to confirm the degree of decidualization in each group. There were no differences in PRL or IGFBP1 expression in the decidualization-matched samples but a marked reduction (P<0.001) in the non-decidualized samples. Decidualization was associated with increased expression of 428 genes including SCARA5 (181-fold), DKK1 (71-fold) and PROK1 (32-fold), and decreased expression of 230 genes including MMP-7 (35-fold) and SFRP4 (21-fold). The top canonical pathways associated with these differentially expressed genes were Natural Killer Cell and Wnt/b-Catenin signaling. Local trophoblast was associated with much less alteration of endometrial gene expression with an increase in 56 genes, including CSH1 (8-fold), and a reduction in 29 genes including CRISP3 (8-fold). The top associated canonical pathway was Antigen Presentation. The study of endometrium from tubal EP may promote novel insights into genes involved in decidualization and those influenced by factors from neighboring trophoblast. This has afforded unique information not highlighted by previous studies and adds to our understanding of the endometrium in early pregnancy.

Antibodies against Helicobacter pylori heat shock protein 60 aggravate HSP60-mediated proinflammatory responses

Anti-Helicobacter pylori heat shock protein 60 (HpHSP60) antibodies are usually found in H. pylori-infected patients and are known to be associated with the progression of gastric diseases. However, the effects of these antibodies on the functions of HpHSP60 have not been identified. This study aims to investigate the effects of the interaction between anti-HSP60 antibodies and HpHSP60 on inflammatory responses. Anti-HpHSP60 polyclonal sera and monoclonal antibodies (mAbs) were produced to evaluate their effects on HpHSP60-induced IL-8 and TNF-α activity. The results indicated that anti-HpHSP60 polyclonal sera collected from patients infected with H. pylori or from rabbit and mice immunized with HpHSP60 could significantly enhance HpHSP60-mediated IL-8 and TNF-α secretion from monocytic THP-1 cells. Similar effects were also found with anti-HpHSP60 mAbs. Further analysis revealed that this phenomenon was only carried out by anti-HpHSP60 antibody but not by other non-specific mAbs. Moreover, the non-specific mAbs decreased the synergism of HpHSP60 and anti-HpHSP60 mAbs in proinflammatory cytokine induction. Herein, we have examined the role of anti-HpHSP60 antibody in host immune responses for the first time. This study demonstrated that H. pylori HSP60/mAbs could modulate helicobacterial pathogenesis by increasing IL-8 and TNF-α production. The pathogen-specific antibodies may execute potential immune functions rather than recognize or neutralize microbes.

Origins of injection-site sarcomas in cats: the possible role of chronic inflammation-a review

The etiology of feline injection-site sarcomas remains obscure. Sarcomas and other tumors are known to be associated with viral infections in humans and other animals, including cats. However, the available evidence suggests that this is not the case with feline injection-site sarcomas. These tumors have more in common with sarcomas noted in experimental studies with laboratory animals where foreign materials such as glass, plastics, and metal are the causal agent. Tumors arising with these agents are associated with chronic inflammation at the injection or implantation sites. Similar tumors have been observed, albeit infrequently, at microchip implantation sites, and these also are associated with chronic inflammation. It is suggested that injection-site sarcomas in cats may arise at the administration site as a result of chronic inflammation, possibly provoked by adjuvant materials, with subsequent DNA damage, cellular transformation, and clonal expansion. However, more fundamental research is required to elucidate the mechanisms involved.

The association of Streptococcus bovis/gallolyticus with colorectal tumors: the nature and the underlying mechanisms of its etiological role

Streptococcus bovis (S. bovis) bacteria are associated with colorectal cancer and adenoma. S. bovis is currently named S. gallolyticus. 25 to 80% of patients with S. bovis/gallolyticus bacteremia have concomitant colorectal tumors. Colonic neoplasia may arise years after the presentation of bacteremia or infectious endocarditis of S. bovis/gallolyticus. The presence of S. bovis/gallolyticus bacteremia and/or endocarditis is also related to the presence of villous or tubular-villous adenomas in the large intestine. In addition, serological relationship of S. gallolyticus with colorectal tumors and direct colonization of S. gallolyticus in tissues of colorectal tumors were found. However, this association is still under controversy and has long been underestimated. Moreover, the etiological versus non-etiological nature of this associationis not settled yet. Therefore, by covering the most of up to date studies, this review attempts to clarify the nature and the core of S. bovis/gallolyicus association with colorectal tumors and analyze the possible underlying mechanisms.

Transcription factor ZBP-89 in cancer growth and apoptosis

ZBP-89, a Krüppel-type zinc-finger transcription factor that binds to GC-rich sequences, is involved in the regulation of cell growth and cell death. It maps to chromosome 3q21 and is composed of 794 residues. Having bifunctional regulatory domains, ZBP-89 may function as a transcriptional activator or repressor of variety of genes such as p16 and vimentin. ZBP-89 arrests cell proliferation through its interactions with p53 and p21(waf1). It is able to stabilize p53 through directly binding and enhance p53 transcriptional activity by retaining it in the nucleus. In addition, ZBP-89 potentiates in butyrate-induced endogenous p21(waf1) up-regulation. ZBP-89 is usually over-expressed in human cancer cells, where it can efficiently induce apoptosis through p53-dependent and -independent mechanisms. Moreover, ZBP-89 is capable of enhancing killing effects of several anti-cancer drugs. Therefore, ZBP-89 may be served as a potential target in cancer therapy.