Vascular endothelial growth factor and neo-angiogenesis in H. pylori gastritis in humans

Bioinformatics and LC-QTOF-MS based discovery of pharmacodynamic and Q-markers of Pitongshu against functional dyspepsia

ETHNOPHARMACOLOGICAL RELEVANCE

Pitongshu (PTS) is a clinically effective empirical formula for the treatment of FD. The efficacy and safety of PTS have been demonstrated in randomized, controlled, double-blind trials, but there is a lack of understanding of the systematic evaluation of the efficacy of PTS and its material basis.

OBJECTIVE

To investigate the efficacy of PTS in Functional dyspepsia (FD) mice and possible Q-markers.

METHOD

In this study, we used "irregular feeding + chronic unpredictable chronic stimulation" to establish a mice model of FD with hepatogastric disharmony. The efficacy of PTS was assessed from hair condition, behavioral, pain, gastrointestinal function, and serum 5-HT, GAS, MTL levels in mice by instillation of different doses of PTS. In addition, the composition of drugs in blood was analyzed by LC-QTOF-MS and potential Q-markers were selected by combining network pharmacology, molecular docking and actual content.

RESULT

Our study showed that different doses of PTS increased pain threshold and writhing latency, decreased the number of writhings, increased gastric emptying rate and small intestinal propulsion rate, decreased total acidity of gastric contents and gastric acid secretion, and increased serum levels of 5-HT, GAS, and MTL in mice to different degrees. Enrichment analysis showed that PTS may be anti-FD through multiple pathways such as Serotonergic synapse, thyroid hormone signaling pathway, cholinergic synapse, and dopaminergic synapse. In addition, potential active ingredient substances were explored by LC-QTOF-MS combined with bioinformatics. Combined with the actual contentselected six constituents, hesperidin, neohesperidin, naringin, paeoniflorin, magnolol and honokiol, possible as Q-markers.

CONCLUSION

PTS may exert its anti-FD effects through multi-component, multi-target and multi-pathway". Constituents, hesperidin, neohesperidin, naringin, paeoniflorin, magnolol and honokiol may be the Q-markers of its anti-FD effects.

Intratumor microbiome: selective colonization in the tumor microenvironment and a vital regulator of tumor biology

The polymorphic microbiome has been proposed as a new hallmark of cancer. Intratumor microbiome has been revealed to play vital roles in regulating tumor initiation and progression, but the regulatory mechanisms have not been fully uncovered. In this review, we illustrated that similar to other components in the tumor microenvironment, the reside and composition of intratumor microbiome are regulated by tumor cells and the surrounding microenvironment. The intratumor hypoxic, immune suppressive, and highly permeable microenvironment may select certain microbiomes, and tumor cells may directly interact with microbiome via molecular binding or secretions. Conversely, the intratumor microbiomes plays vital roles in regulating tumor initiation and progression via regulating the mutational landscape, the function of genes in tumor cells and modulating the tumor microenvironment, including immunity, inflammation, angiogenesis, stem cell niche, etc. Moreover, intratumor microbiome is regulated by anti-cancer therapies and actively influences therapy response, which could be a therapeutic target or engineered to be a therapy weapon in the clinic. This review highlights the intratumor microbiome as a vital component in the tumor microenvironment, uncovers potential mutual regulatory mechanisms between the tumor microenvironment and intratumor microbiome, and points out the ongoing research directions and drawbacks of the research area, which should broaden our view of microbiome and enlighten further investigation directions.

Helicobacter pylori infection induces abnormal expression of pro-angiogenic gene ANGPT2 and miR-203a in AGS gastric cell line

Helicobacter pylori colonizes the stomach and induces an inflammatory response that can develop into gastric pathologies including cancer. The infection can alter the gastric vasculature by the deregulation of angiogenic factors and microRNAs. In this study, we investigate the expression level of pro-angiogenic genes (ANGPT2, ANGPT1, receptor TEK), and microRNAs (miR-135a, miR-200a, miR-203a) predicted to regulate those genes, using H. pylori co-cultures with gastric cancer cell lines. In vitro infections of different gastric cancer cell lines with H. pylori strains were performed, and the expression of ANGPT1, ANGPT2, and TEK genes, and miR-135a, miR-200a, and miR-203a, was quantified after 24 h of infection (h.p.i.). We performed a time course experiment of H. pylori 26695 infections in AGS cells at 6 different time points (3, 6, 12, 28, 24, and 36 h.p.i.). The angiogenic response induced by supernatants of non-infected and infected cells at 24 h.p.i. was evaluated in vivo, using the chicken chorioallantoic membrane (CAM) assay. In response to infection, ANGPT2 mRNA was upregulated at 24 h.p.i, and miR-203a was downregulated in AGS cells co-cultured with different H. pylori strains. The time course of H. pylori 26695 infection in AGS cells showed a gradual decrease of miR-203a expression concomitant with an increase of ANGPT2 mRNA and protein expression. Expression of ANGPT1 and TEK mRNA or protein could not be detected in any of the infected or non-infected cells. CAM assays showed that the supernatants of AGS-infected cells with 26695 strain induced a significantly higher angiogenic and inflammatory response. Our results suggest that H. pylori could contribute to the process of carcinogenesis by downregulating miR-203a, which further promotes angiogenesis in gastric mucosa by increasing ANGPT2 expression. Further investigation is needed to elucidate the underlying molecular mechanisms.

Helicobacter pylori infection induces gastric precancerous lesions and persistent expression of Angpt2, Vegf-A and Tnf-A in a mouse model

Introduction

Helicobacter pylori colonizes the gastric mucosa and induces chronic inflammation.

Methods

Using a mouse model of H. pylori-induced gastritis, we evaluated the mRNA and protein expression levels of proinflammatory and proangiogenic factors, as well as the histopathological changes in gastric mucosa in response to infection. Five- to six-week-old female C57BL/6N mice were challenged with H. pylori SS1 strain. Animals were euthanized after 5-, 10-, 20-, 30-, 40- and 50-weeks post infection. mRNA and protein expression of Angpt1, Angpt2, VegfA, Tnf-α, bacterial colonization, inflammatory response and gastric lesions were evaluated.

Results

A robust bacterial colonization was observed in 30 to 50 weeks-infected mice, which was accompanied by immune cell infiltration in the gastric mucosa. Compared to non-infected animals, H. pylori-colonized animals showed an upregulation in the expression of Tnf-A, Angpt2 and VegfA at the mRNA and protein levels. In contrast, Angpt1 mRNA and protein expression was downregulated in H. pylori-colonized mice.

Conclusion

Our data show that H. pylori infection induces the expression of Angpt2, Tnf-A and Vegf-A in murine gastric epithelium. This may contribute to the pathogenesis of H. pylori-associated gastritis, however the significance of this should be further addressed.

Zuojin Pill attenuates Helicobacter pylori-induced chronic atrophic gastritis in rats and improves gastric epithelial cells function in GES-1 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Zuojin pill (ZJP), a classical Chinese medicine formula, has been widely applied in Chinese clinical practice for the treatment of gastric injury such as acute gastric lesion, acute gastric mucosal injury, chronic unpredictable mild stress, gastroesophageal reflux disease, etc, thereby exerting anti-chronic atrophic gastritis (CAG) effects in traditional Chinese herbal medicine.

AIM OF THE STUDY

This study was aimed to explore the therapeutic effects and molecular mechanisms of ZJP on Helicobacter pylori (H. pylori)-induced CAG based on the comprehensive approaches.

MATERIALS AND METHODS

Sprague-Dawley rats were infected with H. pylori for 8 weeks to establish CAG model. Then, rats in the ZJP groups received doses of 0.63, 1.26, and 2.52 g/kg ZJP for 4 weeks. Therapeutic effects of ZJP on serum indices and the histopathology of the gastric were analyzed in vivo. Moreover, GES-1 cells were infected with H. pylori to establish gastric epithelial cell injury model in vitro. Cell viability and gastric epithelial cell morphology were detected by a high-content screening (HCS) assay. Furthermore, the relative mRNA and protein expression of JMJD2B/COX-2/VEGF axis and HMGB1/NF-κB signaling pathway in vivo and in vitro were determined by RT-PCR and Western Blotting, respectively.

RESULTS

The results showed that the therapeutic effects of ZJP on CAG rats were presented in down-regulation serum biochemical indices and alleviating histological damage of gastric tissue. ZJP could dose-dependently decrease the serum IL-6, MCP-1, PGE2, TNF-α, and VEGF level and significantly improved gastric tissue inflammatory lesions. Besides, ZJP has an effect on increasing cell proliferation of GES-1 cells, ameliorating H. pylori-induced gastric epithelial cell damage. It was found that ZJP has a down-regulating effect on inflammatory reaction and could inhibit the relative mRNA and protein expression of JMJD2B/COX-2/VEGF axis and HMGB1/NF-κB signaling pathway in vivo and in vitro, including JMJD2B, COX-2, VEGF, VEGFR1, and VEGFR2, which in turn reduced the damage of gastric mucosal cells.

CONCLUSIONS

The results suggested that ZJP exerts therapeutic effects on H. pylori-induced CAG by inhibiting the JMJD2B/COX-2/VEGF axis and HMGB1/NF-κB signaling pathway. These findings deeply explained why ZJP could be used to treat CAG clinically and clarified its pharmacological effect and potential mechanism in the treatment of CAG.

Helicobacter pylori as an Initiating Factor of Complications in Patients With Cirrhosis: A Single-Center Observational Study

Background and Aim: The relationship between liver cirrhosis and Helicobacter pylori (H. pylori) is a debatable matter. The aim of this study is to evaluate the possible association between H. pylori infection and liver cirrhosis. Methods: A single-center prospective cohort pilot study of 558 patients with cirrhosis was followed up for 1 year. Serum C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), nitric oxide (NO), vascular endothelial growth factor (VEGF) levels and Fecal H. pylori antigen were evaluated by enzyme-linked immunosorbent assay (ELISA). All patients with positive H. pylori were treated and then followed up for 3 months. Participants with eradicated H. pylori were followed up for one further year. Results: H. pylori-positive patients (48.4%) were associated with increased levels of serum CRP, TNF-α, IL-6, NO, and VEGF, as well as increased incidence of varices, portal hypertensive gastropathy, gastric antral vascular ectasia, hepatocellular carcinoma (HCC), spontaneous bacterial peritonitis, hepatic encephalopathy, portal vein thrombosis (PVT), and hepatorenal syndrome (all P < 0.05). Multivariate analysis models revealed that the presence of H. pylori was an independent risk variable for the development of portal vein thrombosis and hepatocellular carcinoma (P = 0.043, P = 0.037) respectively. After treatment of H. pylori infection, there was a significant reduction in all measured biochemical parameters and reported cirrhotic complications (all P < 0.05). Conclusion: Incidence of PVT and HCC development increased with H. pylori infection through increased inflammatory markers and vascular mediators. Moreover, its eradication may reduce the incidence of these complications.

Association between VEGF-634G>C Gene Polymorphism with Gastric Premalignant Lesions and Serum VEGF Levels in Helicobacter pylori Gastritis Patients

AIM:

To evaluate the association between VEGF-634G>C gene polymorphism with premalignant gastric lesions as well as the level of VEGF.

METHODS:

This cross-sectional study included patients with H. pylori gastritis at Haji Adam Malik General Hospital, Permata Bunda General Hospital, and Universitas Sumatera Utara Hospital, Medan, Indonesia. Detection of H. pylori infection was made using positive results of ¹⁴C-UBT, rapid urease test, and/or immunohistochemistry. Gastric premalignant lesion diagnosis was made when one or more of the following were present: chronic atrophic gastritis, intestinal metaplasia, or dysplasia. Real-time polymerase chain reaction (RT-PCR) was used to examine VEGF-634G>C gene polymorphism. Additionally, serum samples of patients with H. pylori gastritis were obtained to determine the level of circulating VEGF. Data were analysed using SPSS version 22.

RESULTS:

A total number of 87 patients with H. pylori gastritis were included in this study. Of all participants, 26 patients (29.9%) showed gastric premalignancy. There was a significant association between GG+GC genotype of VEGF-634G>C and gastric premalignant lesions (P = 0.003; OR (CI 95%) = 6.07 (1.88-41.71)). VEGF-634 G>C polymorphism also showed an association with VEGF serum levels (P = 0.005). Patients with the GG+GC genotype would be at risk of 3.16 times to have high VEGF levels compared to CC genotypes.

CONCLUSION:

VEGF-634G>C polymorphism, in particular, GG+GC genotype was associated with an increased risk of gastric premalignant transformation as well as having high VEGF levels in patients with H.pylori gastritis.

Mechanisms of angiogenesis in microbe-regulated inflammatory and neoplastic conditions

Commensal microbiota inhabit all the mucosal surfaces of the human body. It plays significant roles during homeostatic conditions, and perturbations in numbers and/or products are associated with several pathological disorders. Angiogenesis, the process of new vessel formation, promotes embryonic development and critically modulates several biological processes during adulthood. Indeed, deregulated angiogenesis can induce or augment several pathological conditions. Accumulating evidence has implicated the angiogenic process in various microbiota-associated human diseases. Herein, we critically review diseases that are regulated by microbiota and are affected by angiogenesis, aiming to provide a broad understanding of how angiogenesis is involved and how microbiota regulate angiogenesis in microbiota-associated human conditions.

Regulation of SIRT3 signal related metabolic reprogramming in gastric cancer by Helicobacter pylori oncoprotein CagA

Injection of the Helicobacter pylori cytotoxin-associated gene A (CagA) is closely associated with the development of chronic gastritis and gastric cancer. Individuals infected with H. pylori possessing the CagA protein produce more reactive oxygen species (ROS) and show an increased risk of developing gastric cancer. Sirtuins (SIRTs) are nicotinamide adenine dinucleotide (NAD⁺)-dependent deacetylases and mitochondrial SIRT3 is known to be a tumor suppressor via its ability to suppress ROS and hypoxia inducible factor 1α (HIF-1α). However, it is unclear whether increased ROS production by H. pylori is regulated by SIRT3 followed by HIF-1α regulation and whether intracellular CagA acts as a regulator thereof. In this study, we investigated correlations among SIRT3, ROS, and HIF-1α in H. pylori-infected gastric epithelial cells. We observed that SIRT3-deficient AGS cells induce HIF-1α protein stabilization and augmented transcriptional activity under hypoxic conditions. In CagA⁺H. pylori infected cells, CagA protein localized to mitochondria where it subsequently suppressed SIRT3 proteins. CagA⁺H. pylori infection also increased HIF-1α activity through the ROS production induced by the downregulated SIRT3 activity, which is similar to the hypoxic condition in gastric epithelial cells. In contrast, overexpression of SIRT3 inhibited the HIF-1α protein stabilization and attenuated the increase in HIF-1α transcriptional activity under hypoxic conditions. Moreover, CagA⁺H. pylori attenuated HIF-1α stability and decreased transcriptional activity in SIRT3-overexpressing gastric epithelial cells. Taken together, these findings provide valuable insights into the potential role of SIRT3 in CagA⁺H. pylori-mediated gastric carcinogenesis and a possible target for cancer prevention via inhibition of HIF-1α.

Serum VEGF Levels in Helicobacter pylori Infection and Correlation with Helicobacter pylori cagA and vacA Genes

BACKGROUND:

Helicobacter pylori vacA and cagA genes are associated with higher virulence. Vascular Endothelial Growth Factor (VEGF) is one important marker for neo-angiogenesis.

AIM:

The purpose of this study was to investigate the relationship between VEGF serum levels with cagA and vacA genes in H. pylori infection.

METHODS:

A cross-sectional study was done on eighty patients that consecutive admitted to endoscopy unit. The diagnosis of H. pylori infection was based on rapid urease test. Serum samples were obtained to determine circulating VEGF level. Polymerase chain reaction was done to examine H. pylori vacA and cagA genes. Data analysis were carried-out using SPSS version 22.

RESULTS:

A total of 80 patients were examined. There were 45 (56.3%) patients infected with Helicobacter pylori. There were 33 (73.3%) patients with H. pylori cagA positive. Serum VEGF levels in patients with the H. pylori positive were significantly higher compared to the patients that have no H. pylori. Serum levels of VEGF were significantly higher in cagA positive than negative.

CONCLUSION:

Serum VEGF level is correlated with H. pylori infection and its virulence status. The more virulence of H. pylori, cagA gene, the higher serum VEGF levels were found.

Helicobacter pylori, liver cirrhosis, and portal hypertension: an updated appraisal

OBJECTIVE

Helicobacter pylori (H. pylori) is the most common cause of gastritis and peptic ulcer. However, H. pylori is even involved in extragastric diseases, and it has been hypothesized that H. pylori could be a risk factor for several hepatic diseases. For instance, a direct involvement of H. pylori in the development of portal hypertension (PH) in cirrhotic patients has been postulated.

METHODS

We performed a literature search in major databases to elucidate the relationship between H. pylori, portal hypertension, and liver cirrhosis.

RESULTS

The effect of H. pylori on PH may be multifactorial. Endothelial dysfunction, alterations in the vasodilating dynamics, and neoangiogenesis are the most appealing theories about this issue, but the proofs come mainly from experimental studies, therefore a solid pathophysiological basis is still to be demonstrated. Congestive gastropathy (CG) and gastric antral vascular ectasia (GAVE) are two common endoscopic entities responsible for acute/chronic upper gastrointestinal bleeding, and a link with H. pylori has been hypothesized: the gastric mucosa, exposed to H. pylori, could develop both inflammatory microcirculatory alterations and thrombi, resembling the histologic pattern of GAVE.

CONCLUSIONS

Despite clues for an association between H. pylori and PH have been shown, these evidences are mostly experimental, therefore, in the absence of a direct proof on human beings, the role of H. pylori in the development of PH is uncertain. However, since this germ may be a cause of peptic ulcer, it should be found and eradicated in cirrhotic patients to reduce the risk of blood loss anemia.

Current advances in targeted therapies for metastatic gastric cancer: improving patient care

In this article, we review the literature on the current advances in targeted therapies for metastatic gastric cancer aimed at improving patient care. We conclude that the key to guiding targeted therapy is individual biomarkers, which are not completely elucidated. HER2 overexpression is the only predictive biomarker currently in use. Furthermore, it is necessary to understand that gastric tumors are heterogeneous; therefore, is impossible to evaluate a novel biological compound without evaluating personal biomarkers. The selection of patients who are able to receive each treatment is paramount for improving advanced gastric cancer survival and reducing unnecessary costs.

Helicobacter pylori secreted peptidyl prolyl cis, trans-isomerase drives Th17 inflammation in gastric adenocarcinoma

Helicobacter pylori infection is characterized by an inflammatory infiltrate, consisting mainly of neutrophils and T cells. This study was undertaken to evaluate the type of gastric T cell response elicited by the secreted peptidyl prolyl cis, trans-isomerase of H. pylori (HP0175) in patients with distal gastric adenocarcinoma. The cytokine profile and the effector functions of gastric tumor-infiltrating lymphocytes (TILs) specific for HP0175 was investigated in 20 patients with distal gastric adenocarcinoma and H. pylori infection. The helper function of HP0175-specific TILs for monocyte MMP-2, MMP-9, and VEGF production was also investigated. TILs cells from H. pylori infected patients with distal gastric adenocarcinoma produced Interleukin (IL)-17 and IL-21 in response to HP0175. HP0175-specific TILs showed poor cytolytic activity while expressing helper activity for monocyte MMP-2, MMP-9 and VEGF production. These findings indicate that HP0175 is able to drive gastric Th17 response. Thus, HP0175, by promoting pro-inflammatory low cytotoxic TIL response, matrix degradation and pro-angiogenic pathways, may provide a link between H. pylori and gastric cancer.

Inhibition of Hydrogen Sulfide-induced Angiogenesis and Inflammation in Vascular Endothelial Cells: Potential Mechanisms of Gastric Cancer Prevention by Korean Red Ginseng

Previously, we reported that Helicobacter pylori-associated gastritis and gastric cancer are closely associated with increased levels of hydrogen sulfide (H₂S) and that Korean red ginseng significantly reduced the severity of H. pylori-associated gastric diseases by attenuating H₂S generation. Because the incubation of endothelial cells with H₂S has been known to enhance their angiogenic activities, we hypothesized that the amelioration of H₂S-induced gastric inflammation or angiogenesis in human umbilical vascular endothelial cells (HUVECs) might explain the preventive effect of Korean red ginseng on H. pylori-associated carcinogenesis. The expression of inflammatory mediators, angiogenic growth factors, and angiogenic activities in the absence or presence of Korean red ginseng extracts (KRGE) were evaluated in HUVECs stimulated with the H₂S generator sodium hydrogen sulfide (NaHS). KRGE efficiently decreased the expression of cystathionine β-synthase and cystathionine γ-lyase, enzymes that are essential for H₂S synthesis. Concomitantly, a significant decrease in the expression of inflammatory mediators, including cyclooxygenase-2 and inducible nitric oxide synthase, and several angiogenic factors, including interleukin (IL)-8, hypoxia inducible factor-1a, vascular endothelial growth factor, IL-6, and matrix metalloproteinases, was observed; all of these factors are normally induced after NaHS. An in vitro angiogenesis assay demonstrated that NaHS significantly increased tube formation in endothelial cells, whereas KRGE pretreatment significantly attenuated tube formation. NaHS activated p38 and Akt, increasing the expression of angiogenic factors and the proliferation of HUVECs, whereas KRGE effectively abrogated this H₂S-activated angiogenesis and the increase in inflammatory mediators in vascular endothelial cells. In conclusion, KRGE was able to mitigate H₂S-induced angiogenesis, implying that antagonistic action against H₂S-induced angiogenesis may be the mechanism underlying the gastric cancer preventive effects of KRGE in H. pylori infection.

[Helicobacter pylori in human stomach: can it be called mutualism or a disease?]

Helicobacter pylori (H. pylori) has been a major concern as a gastric pathogen with unique features since discovered in the end of the 20th century. Recent data on comparative genome study have revealed that H. pylori has successfully survived with its host though over 58,000 years of evolution and migration from continent to continent. To maintain the symbiotic relationship with human, H. pylori has come up with ways to induce host tolerance as well as exert harmful injuries. Studies about H. pylori have accumulated the knowledge about how the cellular and molecular interactions are controlled and regulated to decide whether the symbiotic relationship is directed to diseases or peaceful mutualism. We reviewed recent literatures and research outcomes about the H. pylori and host interaction in molecular and cellular basis.

VEGF-A and VEGF-B mRNA expression in gastro-oesophageal cancers

INTRODUCTION

Angiogenesis is essential for the local growth, invasion and metastasis of the tumours. Vascular endothelial growth factors (VEGFs) play a crucial role in tumour angiogenesis. The aim of our study was to quantify the expression of several VEGF family molecules in human gastro-oesophageal cancers and to analyse possible correlations between genes expression and clinico-pathological features.

MATERIALS AND METHODS

Gene expression was quantified in 43 gastro-oesophageal paired samples using qRT-PCR with TaqMan probes specific to VEGF-A, including soluble transcript variants and VEGF-B genes.

RESULTS

VEGF-A, including the studied splice variants and VEGF-B mRNAs were expressed in both tumour and peritumour mucosa. The expression of VEGF-A and its isoforms was higher in tumour compared with paired peritumour mucosa, while no significant difference was observed in VEGF-B expression. VEGF-A expression tended to correlate with tumour invasion.

CONCLUSION

VEGF-A has a tendency to over-express in gastro-oesophageal cancers, while VEGF-B does not seem involved in these tumours. Further studies are required to establish the utility of anti-VEGF-A therapy and to find biomarkers for pathogenesis or response to therapy in gastro-oesophageal tumours.

Molecular cross-talk between Helicobacter pylori and human gastric mucosa

Helicobacter pylori (H. pylori) has co-evolved with humans to be transmitted from person to person and to colonize the stomach persistently. A well-choreographed equilibrium between the bacterial effectors and host responses permits microbial persistence and health of the host, but confers a risk for serious diseases including gastric cancer. During its long coexistence with humans, H. pylori has developed complex strategies to limit the degree and extent of gastric mucosal damage and inflammation, as well as immune effector activity. The present editorial thus aims to introduce and comment on major advances in the rapidly developing area of H. pylori/human gastric mucosa interaction (and its pathological sequelae), which is the result of millennia of co-evolution of, and thus of reciprocal knowledge between, the pathogen and its human host.

Inflammatory changes of the gastric mucosa and serum concentration of chosen growth factors in children

PURPOSE

To assess whether there is a correlation between the severity of gastritis and concentration of chosen growth factors in the serum of children infected with H. pylori.

MATERIAL AND METHODS

The study included 64 children of whom 50% (Group I) were infected with H. pylori and had gastritis; 18.7% (Group II) of the examined children had a positive titre of IgG against H. pylori and normal gastric mucosa. Controls (Group III) comprised 31.3%. The gastric mucosa was evaluated histopathologically according to the Sydney System. The serum concentrations of growth factors: EGF, TGF-alpha, VEGF, were determined using ELISA.

RESULTS

Mean concentrations of the growth factors were also the highest in Group I compared to Group II and Group III (EGF - 137.3+/-10.4 pg/mL, TGF-alpha - 0.4+/-1.2 pg/mL, VEGF - 146.8 pg/mL). Analysis of correlations between growth factors and the severity of gastritis as well as the activity of antral gastric mucosa inflammation proved that mean EGF concentration in H. pylori infected children was the highest (149.5+/-84.8 pg/mL) in severe gastritis, whereas mean concentrations of TGF-alpha (2.0+/-4.3 pg/mL) and of VEGF (148.1+/-92.6 pg/mL) were the highest in moderate gastritis. Mean concentrations of EGF (155.1+/-116.4 pg/mL) and of VEGF (156.0+/-118.9 pg/mL) were the highest in high activity antral gastritis, whereas the mean concentration of TGF-alpha was the highest (2.0+/-4.2 pg/ml) in moderate activity gastritis.

CONCLUSIONS

In the children with H. pylori infection, serum concentrations of EGF, TGF-alpha, VEGF were the highest in moderate and severe antral gastritis.

Angiogenesis in pre-malignant conditions

Angiogenesis is an essential process involved in the normal growth and differentiation. In its defective and excessive form, angiogenesis is a crucial event in the progression of many human diseases. Excessive angiogenesis was largely investigated in psoriasis, arthritis, diabetic retinopathy and malignant tumours. Soon after the discovery of angiogenic factors and their inhibitors, the angiogenesis jumped from the experimental studies to clinical application. Tumour-associated angiogenesis is nowadays considered as a priority in oncology based on numerous evidences that showed a significant reduction in tumour growth following anti-angiogenic therapy. However, few data are available on pre-malignant conditions. First evidences on angiogenesis in pre-malignant lesions came from the evaluation of microvessel density (MVD). MVD was found to be significantly increased in a relatively large spectrum of pre-malignant squamous cell lesions, such as in the oral mucosa, skin, uterine cervix, vulva and anal canal. For many of them, a correlation was found between MVD and the expression of vascular endothelial growth factor (VEGF). Based on these data, it was suggested that tumour angiogenesis is not necessarily a characteristic of invasive tumour, but may be an early event during tumourigenesis. Additional evidences came from pre-malignant lesions of glandular epithelia, in which the angiogenic switch was demonstrated by the immunohistochemical expression of VEGF in gastric metaplasia and dysplasia, in atypical adenoma of the colon, atypical hyperplasia and carcinoma in situ of the breast and others. Actually, there are convincing evidences for an active angiogenesis in many cases with pre-malignant conditions, and this supports a more accurate evaluation of different chemopreventive agents.

Angiogenesis in pre-malignant conditions

Evidence from human studies suggests that angiogenesis commences during the pre-malignant stages of cancer. Inhibiting angiogenesis may, therefore, be of potential value in preventing progression to invasive cancer. Understanding the mechanisms inducing angiogenesis in these lesions and identification of those important in human tumourigenesis are necessary to develop translational strategies that will help realise the goal of angioprevention.

Helicobacter pylori infection upregulates endothelial nitric oxide synthase expression and induces angiogenesis in gastric mucosa of dyspeptic patients

BACKGROUND

Helicobacter pylori (H. pylori) infection induces nitric acid (NO) overproduction through inducible NO synthase (NOS) expression, subsequent DNA damage and enhanced antiapoptosis signal transduction sequence in the human gastric mucosa, whereas its possible effect on endothelial nitric oxide synthase (eNOS) expression has not as yet been investigated. The aim of this study was to evaluate the effect of H. pylori infection in the expression of eNOS in gastric mucosa.

PATIENTS AND METHODS

We prospectively studied 30 nonsmoking dyspeptic patients (12 men, 18 women, mean age 54.26+/-12.89 years). The diagnosis of H. pylori infection was based mainly on histology. The histological grading of H. pylori infection was evaluated according to the modified Sydney classification. Histological grading of eNOS expression and microvessel density as estimated by CD34 expression were determined by immunohistochemistry (degree 0-3) and correlated with H. pylori infection and histological degree of gastritis.

RESULTS

Twelve patients were H. pylori-positive and 18 patients were H. pylori-negative. The two groups were matched for age (P=0.139), sex (P=0.342) and similar degree of gastritis. Intensity of eNOS and CD34 expression in the corpus and antrum were significantly correlated (P<0.001). eNOS expression was correlated with H. pylori infection in the mucosa of the body and antrum (P=0.013 and 0.037, respectively) but not with gastric inflammation and activity (P=0.848 and 0.871, respectively, for the corpus and P=0.565 and 0.793, respectively, for the antrum). H. pylori-positive patients showed higher expression of CD34-positive blood vessels in the mucosa of the antrum (P=0.048). CD34 expression was correlated with gastric inflammation and activity (P=0.03 and 0.044, respectively) in the mucosa of the antrum of H. pylori-positive patients.

CONCLUSION

H. pylori infection upregulates eNOS, and induces angiogenesis, contributing to H. pylori-associated pathophysiology in gastric mucosa.

New Aspects of Helicobacter pylori Infection Involvement in Gastric Oncogenesis

Gastric adenocarcinoma not located in the cardia still remains second only to lung cancer as the leading cause of cancer-related mortality worldwide, whereas adenocarcinoma of the cardia and gastroesophageal junction has been rapidly rising over the past two decades. Gastric malignancy can be subdivided into diffuse and intestinal pathologic entities that have different epidemiological and prognostic features. Various genetic and environmental factors lead to either abnormal gene overexpression or inappropriate expression of normal genes, whose products confer the malignant phenotype. Advances have been made in genetic changes mostly of the intestinal type; its development is probably a multistep process, as has been well described in colon carcinogenesis. Oncogene overexpression, tumor suppressor loss, and defective DNA mismatch repair is associated with gastric cancer. The most common genetic abnormalities tend to be loss of heterozygosity of particularly tumor suppressor p53 gene or "adenomatous polyposis coli" gene. The latter leads to gastric carcinogenesis through changes related to E-cadherin-catenin complex, which plays a critical role in normal tissue architecture maintenance. Mutation of any of its components results in loss of cell-cell adhesion, thereby contributing to malignancy. Putative trophic factors have also been involved in gastric oncogenesis. E-cadherin/CDH1 gene germline mutations have been recognized in families with an inherited predisposition to diffuse-type malignancy. This review focuses mainly on Helicobacter pylori infection involved in gastric carcinogenesis through various mechanisms, including repopulation of the stomach with bone marrow-derived stem cells that may facilitate gastric cancer progression, thereby necessitating eradication of this bacterium.

Up-regulation of intestinal vascular endothelial growth factor by Afa/Dr diffusely adhering Escherichia coli

BACKGROUND

Angiogenesis has been recently described as a novel component of inflammatory bowel disease pathogenesis. The level of vascular endothelial growth factor (VEGF) has been found increased in Crohn's disease and ulcerative colitis mucosa. To question whether a pro-inflammatory Escherichia coli could regulate the expression of VEGF in human intestinal epithelial cells, we examine the response of cultured human colonic T84 cells to infection by E. coli strain C1845 that belongs to the typical Afa/Dr diffusely adhering E. coli family (Afa/Dr DAEC).

METHODOLOGY

VEGF mRNA expression was examined by Northern blotting and q-PCR. VEGF protein levels were assayed by ELISA and its bioactivity was analysed in endothelial cells. The bacterial factor involved in VEGF induction was identified using recombinant E. coli expressing Dr adhesin, purified Dr adhesin and lipopolysaccharide. The signaling pathway activated for the up-regulation of VEGF was identified using a blocking monoclonal anti-DAF antibody, Western blot analysis and specific pharmacological inhibitors.

PRINCIPAL FINDINGS

C1845 bacteria induce the production of VEGF protein which is bioactive. VEGF is induced by adhering C1845 in both a time- and bacteria concentration-dependent manner. This phenomenon is not cell line dependent since we reproduced this observation in intestinal LS174, Caco2/TC7 and INT407 cells. Up-regulation of VEGF production requires: (1) the interaction of the bacterial F1845 adhesin with the brush border-associated decay accelerating factor (DAF, CD55) acting as a bacterial receptor, and (2) the activation of a Src protein kinase upstream of the activation of the Erk and Akt signaling pathways.

CONCLUSIONS

Results demonstrate that a Afa/Dr DAEC strain induces an adhesin-dependent activation of DAF signaling that leads to the up-regulation of bioactive VEGF in cultured human intestinal cells. Thus, these results suggest a link between an entero-adherent, pro-inflammatory E. coli strain and angiogenesis which appeared recently as a novel component of IBD pathogenesis.

Vascular endothelial growth factor and cyclooxygenase-2 are overexpressed in ileal pouch-anal anastomosis

PURPOSE

Pathophysiology of pouchitis after ileal pouch-anal anastomosis is controversial because of the potential for development of carcinoma. Cyclooxygenase-2-derived prostaglandins may be involved in the inflammatory process and play a role in the pathogenesis of colon cancer. Vascular endothelial growth factor plays a major role in neoangiogenesis and is overexpressed in a number of gastrointestinal malignancies. The goal of this study was to evaluate the expression of cyclooxygenase-2 and vascular endothelial growth factor and to assess neoangiogenesis and epithelial cell proliferation in patients with ileal pouch-anal anastomosis.

METHODS

Endoscopic biopsies were obtained from 15 patients with ileal pouch-anal anastomosis without pouchitis (10 biopsies from the ileal pouch and 10 from ileal nonpouch mucosa) and from 15 subjects with irritable bowel syndrome (10 biopsies from normal-appearing ileum and rectum). Cyclooxygenase-1, cyclooxygenase-2, and vascular endothelial growth factor messenger ribonucleic acid expression was determined by reverse transcriptase polymerase chain reaction. Cyclooxygenase-2 and vascular endothelial growth factor protein expression was evaluated by Western blot. Cyclooxygenase-2, vascular endothelial growth factor, CD34 (neoangiogenesis marker), and Ki67 (proliferation marker) mucosal localizations were evaluated by immunohistochemistry.

RESULTS

Expression of cyclooxygenase-2 and vascular endothelial growth factor was increased in ileal pouch mucosa compared with ileal nonpouch mucosa, normal ileum, and rectum. Cyclooxygenase-2 and vascular endothelial growth factor immunostaining in ileal pouch mucosa was more intense in the crypt area than in the surface epithelium compared with ileal nonpouch mucosa. CD34 (neoangiogenesis marker) and Ki67 (proliferation marker) expression was increased in ileal pouch mucosa.

CONCLUSIONS

Cyclooxygenase-2 and vascular endothelial growth factor are overexpressed in the ileal pouch mucosa. This is associated with increased proliferative activity and neoangiogenesis. Cyclooxygenase-2 and vascular endothelial growth factor overexpression might play a role in the pathogenesis of pouchitis.

Expression and functions of the vascular endothelial growth factors and their receptors in human basophils

Angiogenesis is a multistep complex phenomenon critical for several inflammatory and neoplastic disorders. Basophils, normally confined to peripheral blood, can infiltrate the sites of chronic inflammation. In an attempt to obtain insights into the mechanism(s) underlying human basophil chemotaxis and its role in inflammation, we have characterized the expression and function of vascular endothelial growth factors (VEGFs) and their receptors in these cells. Basophils express mRNA for three isoforms of VEGF-A (121, 165, and 189) and two isoforms of VEGF-B (167 and 186). Peripheral blood and basophils in nasal polyps contain VEGF-A localized in secretory granules. The concentration of VEGF-A in basophils was 144.4 +/- 10.8 pg/10(6) cells. Immunologic activation of basophils induced the release of VEGF-A. VEGF-A (10-500 ng/ml) induced basophil chemotaxis. Supernatants of activated basophils induced an angiogenic response in the chick embryo chorioallantoic membrane that was inhibited by an anti-VEGF-A Ab. The tyrosine kinase VEGFR-2 (VEGFR-2/KDR) mRNA was expressed in basophils. These cells also expressed mRNA for the soluble form of VEGFR-1 and neuropilin (NRP)1 and NRP2. Flow cytometric analysis indicated that basophils express epitopes recognized by mAbs against the extracellular domains of VEGFR-2, NRP1, and NRP2. Our data suggest that basophils could play a role in angiogenesis and inflammation through the expression of several forms of VEGF and their receptors.

Hypoxia-inducible factor-1alpha expression in the gastric carcinogenesis sequence and its prognostic role in gastric and gastro-oesophageal adenocarcinomas

Hypoxia-inducible factor-1 (HIF-1)α expression was studied in the gastric carcinogenesis sequence and as a prognostic factor in surgically resected gastric and gastro-oesophageal junction tumours. Protein expression was examined using immunohistochemistry on formalin-fixed biopsies of normal mucosa (n=20), Helicobacter pylori associated gastritis (n=24), intestinal metaplasia (n=24), dysplasia (n=12) and intestinal (n=19) and diffuse (n=21) adenocarcinoma. The relationship between HIF-1α expression and prognosis was assessed in resection specimens from 177 patients with gastric and gastro-oesophageal junction adenocarcinoma. Hypoxia-inducible factor-1α expression was not observed in normal gastric mucosa but increased in density (P<0.01) and intensity (P<0.01) with progression from H. pylori-associated gastritis, intestinal metaplasia, dysplasia to adenocarcinoma. The pattern of staining in the resection specimens was focally positive in 49 (28%) and at the invasive tumour edge in 41 (23%). Invasive edge expression was associated with lymph node metastases (P=0.034), advanced TNM stage (P=0.001) and was an adverse prognostic factor for cancer-specific survival (P=0.019). In univariate analysis and in comparison with tumours not expressing HIF-1α, invasive edge staining was associated with a hazard ratio of 1.6 (95% CI 1.0−2.5) and focally positive staining a hazard ratio of 0.7 (95% CI 0.5−1.2). Hypoxia-inducible factor-1α lost prognostic significance in multivariate analysis. The results suggest HIF-1α is involved in gastric carcinogenesis and disease progression, but is only a weak prognostic factor for survival.

Mechanisms of Disease: Helicobacter pylori-related gastric carcinogenesis—implications for chemoprevention

Gastric adenocarcinoma is the second most common cause of cancer-related mortality worldwide. Infection with Helicobacter pylori is the single most common cause of adenocarcinoma of the distal stomach. Cancer risk is believed to be related to differences among H. pylori strains and inflammatory responses governed by host genetics. In particular, specific interactions between host factors that modulate the response to the infection, and bacterial virulence factors that can directly cause tissue damage seem to have a major pathogenic role in the development of gastric cancer. In addition, environmental factors can modify key growth signaling pathways within the gastric mucosa, which leads to the alteration of epithelial cell growth. Preventive strategies represent the most promising means of decreasing cancer risk, and must be aimed at the control of H. pylori infection, improvement of environmental conditions, and the identification of subjects who are genetically predisposed to the development of cancer in response to H. pylori infection. Understanding the intracellular signaling pathways that are specifically affected by H. pylori and that promote phenotypic and genotypic changes that might ultimately progress to malignant transformation could enable physicians to focus eradication therapy appropriately and design interventions targeted at the molecular level to prevent the development of gastric cancer.

Pathogenesis of Helicobacter pylori infection

Much interest has been shown in the relationship between Helicobacter pylori infection and gastric carcinogenesis. It is becoming clearer that H. pylori strains carrying a functional cag pathogenicity island (cagPAI), which encodes the type IV secretion system (TFSS) and its effector CagA, play an important role in the development of gastric carcinoma. Furthermore, genetic polymorphism present in the cagA gene appears to influence the degree of an individual cagPAI-positive H. pylori to elicit gastric mucosal lesions, and this process is significantly affected by host genetic polymorphisms such as proinflammatory cytokine gene polymorphisms. Pathomechanism of gastric carcinogenesis associated with H. pylori includes bacteria-host interaction leading to morphologic alterations such as atrophic gastritis and gastrointestinal metaplasia mediated by COX-2 overexpression, cancer cell invasion, and neo-angiogenesis via TLR2/TLR9 system and transcription factors (e.g., NF-kappaB) activation. In addition, H. pylori infection triggers adhesion molecule expression and activity and produces an enhancement in oxidative stress interacting with gastric production of appetite hormone ghrelin and nonsteroidal anti-inflammatory drugs.

H pylori status and angiogenesis factors in human gastric carcinoma

AIM: To investigate H pylori expression in gastric cancer patients in relation to primary tumor angiogenic markers, such as microvessel density (MVD), thymidine phosphorylase (TP), vascular endothelial growth factor receptor-1 (VEGF-R1), p53 and circulating VEGF levels.

METHODS: Angiogenic markers were analyzed immunohistochemically in 56 primary gastric cancers. H pylori cytotoxin (vacA) and the cytotoxin-associated gene (cagA) amplification were evaluated using PCR assay. Serum H pylori IgG antibodies and serum/plasma circulating VEGF levels were detected in 39 and 38 patients by ELISA, respectively.

RESULTS: A total of 69% of patients were positive for circulating IgG antibodies against H pylori. cagA-positive H pylori strains were found in 41% of gastric patients. vacA was found in 50% of patients; s1 strains were more highly expressed among vacA-positive patients. The presence of the s1 strain was significantly associated with cagA (P = 0.0001). MVD was significantly correlated with both tumor VEGF expression (r = 0.361, P = 0.009) and serum VEGF levels (r = -0.347, P = 0.041). Conversely, neither VEGF-R1 expression nor MVD was related to p53 expression. However, H pylori was not related to any angiogenic markers except for the plasma VEGF level (P = 0.026).

CONCLUSION: H pylori antigen is related to higher plasma VEGF levels, but not to angiogenic characteristics. It can be hypothesized that the toxic effects of H pylori on angiogenesis occurs in early preclinical disease phase or in long-lasting aggressive infections, but only when high H pylori IgG levels are persistent.