Persisting and Increasing Neutrophil Infiltration Associates with Gastric Carcinogenesis and E-cadherin Downregulation

IL-8 promotes lens capsular residual cells migration by down-regulates expression of E-cadherin and ZO-1 via the CXCR1/2-NF-κB-RhoA signal pathway

BACKGROUND

Posterior capsular opacification is a major complication following cataract surgery, marked by proliferation, migration, epithelial-mesenchymal transition, and fibrosis of residual epithelial cells. Various inflammatory cytokines are upregulated and contribute to the development of posterior capsular opacification. The effect of interleukin-8 on residual epithelial cells has not been fully determined.

METHODS

Aqueous humor and anterior capsules samples were collected from cataract surgery. Capsular bags from rats and pigs were cultured in DMEM media. Protein and mRNA expressions were measured using immunoblot and qPCR. Cell migration was assessed using the transwell assay.

RESULTS

Interleukin-8 is an early inflammatory factor secreted by residual lens epithelial cells. Migration of lens epithelial cells in aqueous humor positively correlates with interleukin-8 levels, and this effect is inhibited by the receptors of interleukin-8 CXCR1/2 blocker Reparaxin. The expression of tight-junction protein ZO-1 and cell-adhesion protein E-cadherin were down-regulated by administrating interleukin-8, and cell migration of both SRA01/04 cell line in vitro and capsular residual epithelial cells ex vivo were up-regulated via activating RhoA expression and RhoA/GTPase activity. The loss-of- function studies demonstrate that interleukin-8 binding to its receptor CXCR1/2 activates NF-κB/p65, which then turns on the RhoA's expression and RhoA/GTPase activity, and RhoA-modulated the downexpression of E-cadherin and ZO-1 and the increase of cell migration.

CONCLUSIONS

The upregulation in interleukin-8 occurs early in posterior capsular opacification and contributes to down-regulating tight-junctions among epithelial cells and elevates cell migration via the CXCR1/2-NF-κB-RhoA signaling pathway. These demonstrated that interleukin-8 could be a potential target for preventing posterior capsular opacification.

Aβ-Aggregation-Generated Blue Autofluorescence Illuminates Senile Plaques as well as Complex Blood and Vascular Pathologies in Alzheimer's Disease

Senile plaque blue autofluorescence was discovered around 40 years ago, however, its impact on Alzheimer's disease (AD) pathology has not been fully examined. We analyzed senile plaques with immunohistochemistry and fluorescence imaging on AD brain sections and also Aβ aggregation in vitro. In DAPI or Hoechst staining, the nuclear blue fluorescence could only be correctly assigned after subtracting the blue plaque autofluorescence. The flower-like structures wrapping dense-core blue fluorescence formed by cathepsin D staining could not be considered central-nucleated neurons with defective lysosomes since there was no nuclear staining in the plaque core when the blue autofluorescence was subtracted. Both Aβ self-oligomers and Aβ/hemoglobin heterocomplexes generated blue autofluorescence. The Aβ amyloid blue autofluorescence not only labels senile plaques but also illustrates red cell aggregation, hemolysis, cerebral amyloid angiopathy, vascular plaques, vascular adhesions, and microaneurysms. In summary, we conclude that Aβ-aggregation-generated blue autofluorescence is an excellent multi-amyloidosis marker in Alzheimer's disease.

Gastric tubular adenocarcinoma with diffuse neutrophils infiltrating: characteristics and probable treatment strategy

BACKGROUND

Gastric adenocarcinoma is a highly heterogeneous malignancy with varying prognoses. In clinicopathological practice, we noticed a special tubular adenocarcinoma with diffuse neutrophils infiltrating (TADNI). However, the proportion and characteristics of TADNI remain unclear. This study aimed to evaluate the features of TADNI and explore probable treatments.

METHODS

We divided 289 tubular adenocarcinoma cases into the TADNI and non-TADNI (nTADNI) groups by histological neutrophil quantity and performed immunohistochemistry of treatment-associated markers (CXCR1, CXCR2, PD-L1, CD8, HER2 and VEGFR2). Then we evaluated the clinical and morphological features in these cases. We also compared the value of histological features and peripheral blood neutrophil test. In addition, multiomics bioinformatic analyses were performed using the public datasets.

RESULTS

In our cohort, TADNI accounted for 10.4% of all tubular adenocarcinoma cases. These cases had worse prognoses (especially the neutrophils mainly outside the tubes) than nTADNI cases. The histological identification of TADNI had more prognostic value than peripheral blood neutrophils. CXCR1/CXCR2 expression was significantly high in TADNI group which indicated that CXCR1/CXCR2 inhibitors might be beneficial for TADNI patients. There were no significant differences in the expression of PD-L1, CD8, HER2 and VEGFR2. The analyses of TCGA data confirmed that TADNI cases had poorer prognoses and higher CXCR1/CXCR2 expression. Bioinformatic results also revealed molecular features (more hsa-mir-223 expression, fewer CD8-positive T cells and regulatory T cells, tighter communication between tumor cells' CXCR1/CXCR2 and neutrophils' CXCL5/CXCL8) of this type.

CONCLUSIONS

TADNI is a special morphological subtype with poorer prognoses and unique molecular characteristics, which might benefit from CXCR1/CXCR2 inhibitors.

Comparison of Helicobacter pylori positive and negative gastric cancer via multi-omics analysis

IMPORTANCE

This is the first clinical research to systematically expound the difference between gastric cancer (GC) individuals with Helicobacter pylori and GC individuals without H. pylori from the perspective of multi-omics. This clinical study identified significant genes, microbes, and fecal metabolites, which exhibited nice power for differentiating GC individuals with H. pylori infection from GC individuals without H. pylori infection. This study provides a crucial basis for a better understanding of eradication therapy among the GC population.

Vaccination with Helicobacter pylori attachment proteins protects against gastric cancer

Most cases of gastric cancer are caused by chronic Helicobacter pylori infection, but the lack of early onco-diagnostics and a high risk for antibiotic resistance hampers early intervention through eradication of H. pylori infection by antibiotics. We reported on a protective mechanism where H. pylori gastric mucosal attachment can be reduced by natural antibodies that block the binding of its attachment protein BabA. Here we show that challenge infection with H. pylori induced response of such blocking antibodies in both human volunteers and in rhesus macaques, that mucosal vaccination with BabA protein antigen induced blocking antibodies in rhesus macaques, and that vaccination in a mouse model induced blocking antibodies that reduced gastric mucosal inflammation, preserved the gastric juice acidity, and fully protected the mice from gastric cancer caused by H. pylori.

Recent Insight about HE4 Role in Ovarian Cancer Oncogenesis

Currently, ovarian cancer (OC) is a target of intense biomarkers research because of its frequent late diagnosis and poor prognosis. Serum determination of Human epididymis protein 4 (HE4) is a very important early detection test. Most interestingly, HE4 plays a unique role in OC as it has been implicated not only in OC diagnosis but also in the prognosis and recurrence of this lethal neoplasm, actually acting as a clinical biomarker. There are several evidence about the predictive power of HE4 clinically, conversely less has been described concerning its role in OC oncogenesis. Based on these considerations, the main goal of this review is to clarify the role of HE4 in OC proliferation, angiogenesis, metastatization, immune response and also in the development of targeted therapy. Through a deeper understanding of its functions as a key molecule in the oncogenetic processes underlying OC, HE4 could be possibly considered as an essential resource not only for diagnosis but also for prognosis and therapy choice.

NGS Data Repurposing Allows Detection of tRNA Fragments as Gastric Cancer Biomarkers in Patient-Derived Extracellular Vesicles

Transfer RNA fragments (tRFs) have gene silencing effects similarly to miRNAs, can be sorted into extracellular vesicles (EVs) and are emerging as potential circulating biomarkers for cancer diagnoses. We aimed at analyzing the expression of tRFs in gastric cancer (GC) and understanding their potential as biomarkers. We explored miRNA datasets from gastric tumors and normal adjacent tissues (NATs) from TCGA repository, as well as proprietary 3D-cultured GC cell lines and corresponding EVs, in order to identify differentially represented tRFs using MINTmap and R/Bioconductor packages. Selected tRFs were validated in patient-derived EVs. We found 613 Differentially Expressed (DE)-tRFs in the TCGA dataset, of which 19 were concomitantly upregulated in TCGA gastric tumors and present in 3D cells and EVs, but barely expressed in NATs. Moreover, 20 tRFs were expressed in 3D cells and EVs and downregulated in TCGA gastric tumors. Of these 39 DE-tRFs, 9 tRFs were also detected in patient-derived EVs. Interestingly, the targets of these 9 tRFs affect neutrophil activation and degranulation, cadherin binding, focal adhesion and the cell-substrate junction, highlighting these pathways as major targets of EV-mediated crosstalk with the tumor microenvironment. Furthermore, as they are present in four distinct GC datasets and can be detected even in low quality patient-derived EV samples, they hold promise as GC biomarkers. By repurposing already available NGS data, we could identify and cross-validate a set of tRFs holding potential as GC diagnosis biomarkers.

Estimating the Global Burden of Epstein-Barr Virus-Associated Gastric Cancer: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Evidence suggests that a fraction of new gastric cancer cases may be etiologically associated with Epstein-Barr virus (EBV), a known carcinogenic agent. We aimed to systematically explore the proportion of EBV-positive gastric cancer.

METHODS

We did a systematic review (PROSPERO CRD42020164473) from January 1990 to August 2021. For each country and geographical region with available data, pooled prevalence and corresponding 95% confidence intervals (CIs) of EBV in gastric tumors were calculated for 3 subtypes of gastric adenocarcinoma (conventional adenocarcinoma, lymphoepithelioma-like gastric carcinoma, and remnant/stump carcinoma). For conventional adenocarcinoma, prevalence ratios (PRs) were presented for sex, Lauren's classification, gastric cancer stage, and anatomical location of the stomach.

RESULTS

In 220 eligible studies including over 68,000 cases of conventional gastric adenocarcinoma, EBV prevalence in tumor cells was 7.5% (95% CI, 6.9%-8.1%) and was higher in men compared with women (PR, 2.1; 95% CI, 1.9-2.4), in diffuse type compared with intestinal type (PR, 1.3; 95% CI, 1.1-1.5), and in the proximal region compared with the distal region (PR, 2.5; 95% CI, 2.0-3.1). There was no difference in EBV prevalence by gastric cancer stage. EBV prevalence was 75.9% (95% CI, 62.8%-85.5%) among lymphoepithelioma-like gastric carcinoma and 26.3% (95% CI, 22.2%-32.0%) among remnant or stump carcinoma.

CONCLUSIONS

Assuming a causal association between EBV and gastric cancer, our findings, when applied to the GLOBOCAN 2020 gastric cancer incidence, suggest that primary prevention such as the development of an effective EBV vaccine might prevent 81,000 EBV-associated gastric cancer cases worldwide annually.

Helicobacter pylori and gastric microbiota homeostasis: progress and prospects

Helicobacter pylori, a Gram-negative microaerobic bacteria belonging to the phylum Proteobacteria, can colonize in the stomach and duodenum, and cause a series of gastrointestinal diseases such as gastritis, gastric ulcer and even gastric cancer. At present, the high diversity of the microorganisms in the stomach has been confirmed with culture-independent methods; some researchers have also studied the stomach microbiota composition at different stages of H. pylori carcinogenesis. Here, we mainly review the possible role of H. pylori-mediated microbiota changes in the occurrence and development of gastric cancer to provide new ideas for preventing H. pylori infection and regulating microecological imbalance.

Senile plaques in Alzheimer's disease arise from Aβ- and Cathepsin D-enriched mixtures leaking out during intravascular haemolysis and microaneurysm rupture

Senile plaques are a pathological hallmark of Alzheimer's disease (AD), yet the mechanism underlying their generation remains unknown. Beta-amyloid peptide (Aβ) is a major component of senile plaques. We analysed AD brain tissues with histochemistry, immunohistochemistry and fluorescence imaging to examine the neural, vascular or blood Aβ contribution to senile plaque development. We found little neural marker co-expression with plaque Aβ, while co-expression of blood markers, such as Haemin and ApoE, was abundant. The plaque cores were structured with vascular and glial proteins outside and blood metabolites inside, co-localizing with a characteristic of Hoechst staining-independent blue autofluorescence. Erythrocyte-interacting Aβ is linked to coagulation, elevated calcium and blue autofluorescence, and it is associated with intravascular haemolysis, atherosclerosis, cerebral amyloid angiopathy, microaneurysm, and often with Cathepsin D co-expression. We identified microaneurysms as major sites of amyloid formation. Our data suggest that senile plaques arise from Aβ- and Cathepsin D-enriched mixtures leaking out during intravascular haemolysis and microaneurysm rupture.

Emerging Role of Helicobacter pylori in the Immune Evasion Mechanism of Gastric Cancer: An Insight Into Tumor Microenvironment-Pathogen Interaction

Helicobacter pylori (H. pylori) infection is the strongest causative factor of gastric cancer. Growing evidence suggests that the complex crosstalk of H. pylori and the tumor microenvironment (TME) exerts a profound influence on gastric cancer progression. Hence, there is emerging interest to in-depth comprehension of the mechanisms of interplay between H. pylori and the TME. This review discusses the regulatory mechanisms underlying the crosstalk between H. pylori infection and immune and stromal cells, including tumor-associated macrophages (TAMs), neutrophils, dendritic cells, myeloid-derived suppressor cells (MDSCs), natural killer (NK) cells, B and T cells, cancer associated fibroblasts (CAFs), and mesenchymal stem cells (MSCs), within the TME. Such knowledge will deepen the understanding about the roles of H. pylori in the immune evasion mechanism in gastric cancer and contribute to the development of more effective treatment regimens against H. pylori-induced gastric cancer.

Targeting IL8 as a sequential therapy strategy to overcome chemotherapy resistance in advanced gastric cancer

Systemic chemotherapy with multiple drug regimens is the main therapy option for advanced gastric cancer (GC) patients. However, many patients develop relapse soon. Here, we evaluated the therapeutic potential of targeting interleukin-8 (IL8) to overcome resistance to chemotherapy in advanced GC. RNA sequencing revealed crucial molecular changes after chemotherapy resistance, in which the expression of IL8 was significantly activated with the increase in drug resistance. Subsequently, the clinical significance of IL8 expression was determined in GC population specimens. IL8-targeted by RNA interference or reparixin reversed chemotherapy resistance with limited toxicity in vivo and vitro experiments. Sequential treatment with first-line, second-line chemotherapy and reparixin inhibited GC growth, reduced toxicity and prolonged survival. Collectively, our study provides a therapeutic strategy that targeting IL8 as a sequential therapy after chemotherapy resistance in advanced GC.

CD10 and Das1: a biomarker study using immunohistochemistry to subtype gastric intestinal metaplasia

Background

Intestinal metaplasia (IM) is considered a key pivot point in the Correa model of gastric cancer (GC). It is histologically subtyped into the complete and incomplete subtypes, the latter being associated with a greater risk of progression. However, the clinical utility of IM subtyping remains unclear, partially due to the absence of reliable defining biomarkers.

Methods

Based on gene expression data and existing literature, we selected CD10 and Das1 as candidate biomarkers to distinguish complete and incomplete IM glands in tissues from patients without GC (IM-GC) and patients with GC (IM + GC). Immunohistochemical staining of individually subtyped IM glands was scored after blinding by two researchers using tissue belonging to both IM-GC and IM + GC patients. Whole tissue Das1 staining was further assessed using digital image quantification (cellSens Dimension, Olympus).

Results

Across both cohorts CD10 stained the IM brush border and was shown to have a high sensitivity (87.5% and 94.9% in IM-GC and IM + GC patients respectively) and specificity (100.0% and 96.7% respectively) with an overall AUROC of 0.944 for complete IM glands. By contrast Das1 stained mainly goblet cells and the apical membrane of epithelial cells, mostly of incomplete IM glands with a low sensitivity (28.6% and 29.3% in IM-GC and IM + GC patients respectively) but high specificity (98.3% and 85.1% respectively) and an overall AUROC of 0.603 for incomplete IM glands. A combined logistic regression model showed a significant increase in AUROC for detecting complete IM glands (0.955 vs 0.970). Whole tissue digital quantification of Das1 staining showed a significant association with incomplete IM compared to complete IM, both in IM-GC and in IM + GC patients (p = 0.016 and p = 0.009 respectively, Mann–Whitney test and unpaired t test used). Additionally, complete IM in IM + GC patients exhibited significantly more Das1 staining than in IM-GC patients (p = 0.019, Mann–Whitney test).

Conclusions

These findings suggest that CD10 is an outstanding biomarker for complete IM and Das1 may be useful as a secondary biomarker for IM glands at greater risk of progression irrespective of IM subtype. Overall, the clinical use of these biomarkers could lead to improved patient stratification and targeted surveillance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02268-z.

Autophagy mediates ER stress and inflammation in Helicobacter pylori-related gastric cancer

Autophagy is a cellular degradation mechanism, which is triggered by the bacterium Helicobacter pylori. A single nucleotide polymorphism (SNP) in the autophagy gene ATG16L1 (rs2241880, G-allele) has been shown to dysregulate autophagy and increase intestinal endoplasmic reticulum (ER) stress. Here, we investigate the role of this SNP in H.pylori-mediated gastric carcinogenesis and its molecular pathways. ATG16L1 rs2241880 was genotyped in subjects from different ethnic cohorts (Dutch and Australian) presenting with gastric (pre)malignant lesions of various severity. Expression of GRP78 (a marker for ER stress) was assessed in gastric tissues. The effect of ATG16L1 rs2241880 on H.pylori-mediated ER stress and pro-inflammatory cytokine induction was investigated in organoids and CRISPR/Cas9 modified cell lines. Development of gastric cancer was associated with the ATG16L1 rs2241880 G-allele. Intestinal metaplastic cells in gastric tissue of patients showed increased levels of ER-stress. In vitro models showed that H.pylori increases autophagy while reducing ER stress, which appeared partly mediated by the ATG16L1 rs2241880 genotype. H.pylori-induced IL-8 production was increased while TNF-α production was decreased, in cells homozygous for the G-allele. The ATG16L1 rs2241880 G-allele is associated with progression of gastric premalignant lesions and cancer. Modulation of H.pylori-induced ER stress pathways and pro-inflammatory mediators by ATG16L1 rs2441880 may underlie this increased risk.

Innate Immune Responses in Pediatric Patients with Gastritis—A Trademark of Infection or Chronic Inflammation?

The aim of this study was to define the relationship between several environmental, laboratory, and genetic factors, i.e., TLR2 and NLRP3 polymorphisms, and Helicobacter pylori (H. pylori) infection in children, by comparing three different groups of pediatric subjects: H. pylori-induced gastritis, non-H. pylori gastritis, and healthy controls. Our final study sample included 269 children, which were divided into three groups according to the histopathological exam: group 1 with 51 children with H. pylori-induced gastritis, group 2 with 103 children with H. pylori-negative gastritis, and group 3 (control group) with 115 children without any histopathological changes. All children underwent a thorough anamnesis, clinical exam, laboratory tests, and upper digestive endoscopy with gastric biopsy for rapid urease test, histopathological exam, and genetic analysis of TLR2 rs3804099, TLR2 rs3804100, and NLRP3 rs10754558 gene polymorphisms. We noticed a significant association between living conditions and the type of gastritis (p < 0.0001). Both rapid urease and serological tests were significantly associated with the presence of H. pylori (p < 0.0001). The CT variant genotype of TLR2 rs380499 was significantly associated with neutrophil count (p = 0.0325). We noticed a significant association between the CC variant genotype of NLRP3 rs10754558 and leucocytes, neutrophils, eosinophils, as well as ALT (p = 0.0185, p = 0.0379, p = 0.0483, p = 0.0356). Based on these findings, we state that poor living conditions and rural areas represent risk factors for H. pylori infection. The rapid urease test is a reliable diagnostic tool for this infection. CT and TT carriers of TLR2 rs3804099, as well as CC carriers of NLRP3 rs10754558, might display a more severe degree of systemic inflammation.

Molecular Landscapes of Gastric Pre-Neoplastic and Pre-Invasive Lesions

Gastric carcinoma (GC) represents one of the most common and most lethal malignancies worldwide. The histopathological characterization of GC precursor lesions has provided great knowledge about gastric carcinogenesis, with the consequent introduction of effective strategies of primary and secondary prevention. In recent years, a large amount of data about the molecular events in GC development is emerging, flanking the histomorphological descriptions. In this review, we describe the landscape of molecular alterations in gastric pre-invasive lesions with a glance at their potential use in the diagnostic and therapeutic decision-making process.

Cathepsins in Bacteria-Macrophage Interaction: Defenders or Victims of Circumstance?

Macrophages are the first encounters of invading bacteria and are responsible for engulfing and digesting pathogens through phagocytosis leading to initiation of the innate inflammatory response. Intracellular digestion occurs through a close relationship between phagocytic/endocytic and lysosomal pathways, in which proteolytic enzymes, such as cathepsins, are involved. The presence of cathepsins in the endo-lysosomal compartment permits direct interaction with and killing of bacteria, and may contribute to processing of bacterial antigens for presentation, an event necessary for the induction of antibacterial adaptive immune response. Therefore, it is not surprising that bacteria can control the expression and proteolytic activity of cathepsins, including their inhibitors – cystatins, to favor their own intracellular survival in macrophages. In this review, we summarize recent developments in defining the role of cathepsins in bacteria-macrophage interaction and describe important strategies engaged by bacteria to manipulate cathepsin expression and activity in macrophages. Particularly, we focus on specific bacterial species due to their clinical relevance to humans and animal health, i.e., Mycobacterium, Mycoplasma, Staphylococcus, Streptococcus, Salmonella, Shigella, Francisella, Chlamydia, Listeria, Brucella, Helicobacter, Neisseria, and other genera.

Endoscopy-based Kyoto classification score of gastritis related to pathological topography of neutrophil activity

BACKGROUND

Endoscopy-based Kyoto classification for gastritis and pathological topographic distribution of neutrophil infiltration are correlated with gastric cancer risk.

AIM

To investigate the association between Kyoto classification and the topographic distribution of neutrophil activity.

METHODS

Kyoto classification score, ranging from 0 to 8, consisted of atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness. Neutrophil activity was scored according to the updated Sydney System using biopsy samples obtained from the greater curvature of the corpus and the antrum. The participants were divided into four categories, inactive stomach, antrum-predominant gastritis, pangastritis, and corpus-predominant gastritis, based on the topographic distribution of neutrophil activity. Effects of sex, age, body mass index, drinking habit, smoking habit, family history of gastric cancer, serum Helicobacter pylori (H. pylori) antibody, and Kyoto score on topography of neutrophil infiltration were analyzed.

RESULTS

A total of 327 patients (comprising 50.7% women, with an average age of 50.2 years) were enrolled in this study. H. pylori infection rate was 82.9% with a mean Kyoto score of 4.63. The Kyoto score was associated with the topographic distribution of neutrophil activity. Kyoto scores were significantly higher in the order of inactive stomach, antrum-predominant gastritis, pangastritis, and corpus-predominant gastritis (3.05, 4.57, 5.21, and 5.96, respectively). Each individual score of endoscopic findings (i.e., atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness) was correlated with the topographic distribution of neutrophil activity. On multivariate analysis, the Kyoto score, age, and serum H. pylori antibody were independently associated with the topographic distribution of neutrophil activity.

CONCLUSION

The Kyoto classification score was associated with the topographic distribution of neutrophil activity.

Unveiling the Crucial Role of Type IV Secretion System and Motility of Helicobacter pylori in IL-1β Production via NLRP3 Inflammasome Activation in Neutrophils

Helicobacter pylori is a gram-negative, microaerophilic, and spiral-shaped bacterium and causes gastrointestinal diseases in human. IL-1β is a representative cytokine produced in innate immune cells and is considered to be a key factor in the development of gastrointestinal malignancies. However, the mechanism of IL-1β production by neutrophils during H. pylori infection is still unknown. We designed this study to identify host and bacterial factors involved in regulation of H. pylori-induced IL-1β production in neutrophils. We found that H. pylori-induced IL-1β production is abolished in NLRP3-, ASC-, and caspase-1/11-deficient neutrophils, suggesting essential role for NLRP3 inflammasome in IL-1β response against H. pylori. Host TLR2, but not TLR4 and Nod2, was also required for transcription of NLRP3 and IL-1β as well as secretion of IL-1β. H. pylori lacking cagL, a key component of the type IV secretion system (T4SS), induced less IL-1β production in neutrophils than did its isogenic WT strain, whereas vacA and ureA were dispensable. Moreover, T4SS was involved in caspase-1 activation and IL-1β maturation in H. pylori-infected neutrophils. We also found that FlaA is essential for H. pylori-mediated IL-1β production in neutrophils, but not dendritic cells. TLR5 and NLRC4 were not required for H. pylori-induced IL-1β production in neutrophils. Instead, bacterial motility is essential for the production of IL-1β in response to H. pylori. In conclusion, our study shows that host TLR2 and NLRP3 inflammasome and bacterial T4SS and motility are essential factors for IL-1β production by neutrophils in response to H. pylori.

The biomarker HE4 (WFDC2) promotes a pro-angiogenic and immunosuppressive tumor microenvironment via regulation of STAT3 target genes

Epithelial ovarian cancer (EOC) is a highly lethal gynecologic malignancy arising from the fallopian tubes that has a high rate of chemoresistant recurrence and low five-year survival rate. The ovarian cancer biomarker HE4 is known to promote proliferation, metastasis, chemoresistance, and suppression of cytotoxic lymphocytes. In this study, we sought to examine the effects of HE4 on signaling within diverse cell types that compose the tumor microenvironment. HE4 was found to activate STAT3 signaling and promote upregulation of the pro-angiogenic STAT3 target genes IL8 and HIF1A in immune cells, ovarian cancer cells, and endothelial cells. Moreover, HE4 promoted increases in tube formation in an in vitro model of angiogenesis, which was also dependent upon STAT3 signaling. Clinically, HE4 and IL8 levels positively correlated in ovarian cancer patient tissue. Furthermore, HE4 serum levels correlated with microvascular density in EOC tissue and inversely correlated with cytotoxic T cell infiltration, suggesting that HE4 may cause deregulated blood vessel formation and suppress proper T cell trafficking in tumors. Collectively, this study shows for the first time that HE4 has the ability to affect signaling events and gene expression in multiple cell types of the tumor microenvironment, which could contribute to angiogenesis and altered immunogenic responses in ovarian cancer.

Lipopolysaccharides From Non-Helicobacter pylori Gastric Bacteria Potently Stimulate Interleukin-8 Production in Gastric Epithelial Cells

Gastric acid secretion is compromised in chronic Helicobacter pylori (H. pylori) infection allowing overgrowth of non-H. pylori gastric bacteria (NHGB) in the stomach.

Enhanced neutrophil functions during Opisthorchis viverrini infections and correlation with advanced periductal fibrosis

Millions of people are infected with the liver fluke, Opisthorchis viverrini (OV), but only ~25% of those infected develop liver disease and even fewer develop cholangiocarcinoma. The reasons for these differential outcomes following infection are unknown but it has been proposed that differential immune responses to the parasite may play a role. We therefore measured granulocyte (neutrophil) function in OV-infected individuals, with and without advanced periductal fibrosis, to determine if these cells have a "pro-inflammatory" phenotype that may contribute to liver disease post-infection. A case-controlled study (n = 54 in each cohort) from endemic OV-infected areas of northeastern Thailand measured neutrophil functions in whole blood from non-infected (healthy controls) and OV-infected individuals with and without APF. We measured reactive oxygen species production, phagocytosis, receptor expression and apoptosis. Secreted products from OV cultures (obtained after in vitro culture of parasites) stimulated reactive oxygen species production in non-infected healthy controls, but levels were two-fold greater after OV infection (P < 0.0001); neutrophil reactive oxygen species production in individuals with APF was double that observed in those without APF (P < 0.0001). OV-infected neutrophils had elevated CD11b expression and greater phagocytic capacity, which was even three-fold higher in those with advanced periductal fibrosis (P < 0.0001). This "activated" phenotype of circulating neutrophils was further confirmed by the observation that isolated neutrophils had delayed apoptosis ex vivo. We believe this is the first study to show that circulating blood neutrophil function is enhanced following OV infection and is more activated in those with advanced periductal fibrosis. We propose that this activated phenotype could contribute to the pathology of liver disease. These data support the hypothesis of an activated innate inflammatory phenotype following OV infection and provide the first evidence for involvement of neutrophils in disease pathology.

Sexual dimorphism in gastric cancer: tumor-associated neutrophils predict patient outcome only for women

PURPOSE

Tumor-associated neutrophils (TANs) are part of the tumor immune microenvironment (TIME) and may contribute to gastric cancer (GC) biology. We hypothesized that TAN are enriched in the TIME, show sex-specific differences, and correlate with patient outcome.

METHODS

We analyzed the distribution and putative tumor biological significance of TANs in a well-characterized, therapy-naïve, European GC cohort using immunohistochemical staining of myeloperoxidase (MPO), and digital image analysis using Definiens Tissue Studio^®.

RESULTS

Different tumor compartments were examined, and TAN densities were correlated with various clinicopathological patient characteristics. TAN density showed a large interindividual variability ranging from 0 to 6711.0 TANs/mm². Intratumoral distribution patterns were inhomogeneous (tumor surface vs. tumor center vs. invasion front) and correlated significantly with Laurén phenotype, tumor grade, and microsatellite status in the tumor center and invasion front. In the multivariate analysis, TAN density in the invasion front was an independent predictor of tumor-specific survival only for women (HR = 2.77, p   < 0.001). In men, no correlation was found between TAN density and survival.

CONCLUSION

With regard to TANs, our study independently validates sexual dimorphism in GC biology.

Premalignant lesions and gastric cancer: Current understanding

Over the last two decades there has been a broad paradigm shift in our understanding of gastric cancer (GC) and its premalignant states from gross histological models to increasingly precise molecular descriptions. In this review we reflect upon the historic approaches to describing premalignant lesions and GC, highlight the current molecular landscape and how this could inform future risk assessment prevention strategies.

E-cadherin Downregulation and microRNAs in Sporadic Intestinal-Type Gastric Cancer

CDH1 gene, encoding E-cadherin, is a tumor suppressor gene frequently altered in gastric cancers (GCs) of both diffuse (DGC) and intestinal (IGC) histotypes, albeit through different mechanisms. The study aimed to characterize CDH1 expression in sporadic IGC and to investigate whether microRNAs (miRs) are involved in its transcriptional control. We evaluated CDH1 expression by quantitative real-time PCR (RT-qPCR) in 33 IGC patients and found a significant downregulation in tumor tissues compared to normal counterparts (p-value = 0.025). Moreover, 14 miRs, predicted to be involved in CDH1 regulation in both a direct and indirect manner, were selected and analyzed by RT-qPCR in an independent case series of 17 IGCs and matched normal tissues. miR-101, miR-26b, and miR-200c emerged as significantly downregulated and were confirmed in the case series of 33 patients (p-value < 0.001). Finally, we evaluated EZH2 expression, a target of both miR-101 and miR-26b, which showed significant upregulation in IGCs (p-value = 0.005). A significant inverse correlation was observed between EZH2 overexpression and CDH1, miR-101, and miR-26b levels (p-value < 0.001). Our results reinforce the link between CDH1 and IGC, highlighting the role of miRs in its transcriptional control and improving our understanding of GC subtypes and biomarkers.

Crosstalk Between DNA Damage and Inflammation in the Multiple Steps of Gastric Carcinogenesis

Over the last years, intensive investigations in molecular biology and cell physiology extended tremendously the knowledge about the association of inflammation and cancer. In frame of this paradigm, the human pathogen Helicobacter pylori triggers gastritis and gastric ulcer disease, and contributes to the development of gastric cancer. Mechanisms, by which the bacteria-induced inflammation in gastric mucosa leads to intestinal metaplasia and carcinoma, are represented in this review. An altered cell-signaling response and increased production of free radicals by epithelial and immune cells account for the accumulation of DNA damage in gastric mucosa, if infection stays untreated. Host genetics and environmental factors, especially diet, can accelerate the process, which offers the opportunity of intervention based on a balanced nutrition. It is supposed that inflammation might influence stem- or progenitor cells in gastric tissue predisposing for metaplasia or tumor relapse. Herein, DNA is strongly mutated and labile, which restricts therapy options. Thus, the understanding of the mechanisms that underlie gastric carcinogenesis will be of preeminent importance for the development of strategies for screening and early detection. As most gastric cancer patients face late-stage disease with a poor overall survival, the development of multi-targeted therapeutic intervention strategies is a major challenge for the future.

Gastric Microbiota in Helicobacter pylori-Negative and -Positive Gastritis Among High Incidence of Gastric Cancer Area

Helicobacter pylori (H. pylori) related chronic gastritis is a well-known major etiological factor for gastric cancer development. However, H. pylori-negative gastritis (HpN) is not well described. We aimed to examine gastric mucosal microbiota in HpN compared to H. pylori-positive gastritis (HpP) and H. pylori-negative non-gastritis group (control). Here, we studied 11 subjects with HpN, 40 with HpP and 24 controls. We performed endoscopy with six gastric biopsies. Comparison groups were defined based on strict histological criteria for the disease and H. pylori diagnosis. We used 16S rRNA gene amplicon sequencing to profile the gastric microbiota according to comparison groups. These results demonstrate that the HpP group had significantly lower bacterial richness by the operational taxonomic unit (OTU) counts, and Shannon and Simpson indices as compared to HpN or controls. The linear discriminant analysis effect size analysis showed the enrichment of Firmicutes, Fusobacteria, Bacteroidetes and Actinobacteria at phylum level in the HpN group. In the age-adjusted multivariate analysis, Streptococcus sp. and Haemophilus parainfluenzae were at a significantly increased risk for HpN (odds ratio 18.9 and 12.3, respectively) based on abundance. Treponema sp. was uniquely found in HpN based on occurrence. In this paper, we conclude that Streptococcus sp., Haemophilus parainfluenzae and Treponema sp. are candidate pathogenic bacterial species for HpN. These results if confirmed may have important clinical implications.

Contribution of Wound-Associated Cells and Mediators in Orchestrating Gastrointestinal Mucosal Wound Repair

The gastrointestinal mucosa, structurally formed by the epithelium and lamina propria, serves as a selective barrier that separates luminal contents from the underlying tissues. Gastrointestinal mucosal wound repair is orchestrated by a series of spatial and temporal events that involve the epithelium, recruited immune cells, resident stromal cells, and the microbiota present in the wound bed. Upon injury, repair of the gastrointestinal barrier is mediated by collective migration, proliferation, and subsequent differentiation of epithelial cells. Epithelial repair is intimately regulated by a number of wound-associated cells that include immune cells and stromal cells in addition to mediators released by luminal microbiota. The highly regulated interaction of these cell types is perturbed in chronic inflammatory diseases that are associated with impaired wound healing. An improved understanding of prorepair mechanisms in the gastrointestinal mucosa will aid in the development of novel therapeutics that promote mucosal healing and reestablish the critical epithelial barrier function.

Estrogen Action in the Epithelial Cells of the Mouse Vagina Regulates Neutrophil Infiltration and Vaginal Tissue Integrity

In the female reproductive tract, the innate immune system is modulated by two sex steroid hormones, estrogen and progesterone. A cyclical wave of neutrophils in the vaginal lumen is triggered by chemokines and correlates with circulating estrogen levels. Classical estrogen signaling in the female reproductive tract is activated through estrogen receptor α (encoded by the Esr1 gene). To study the role of estrogen action in the vagina, we used a mouse model in which Esr1 was conditionally ablated from the epithelial cells (Wnt7a^cre/+; Esr1^f/f). Histological evidence showed that in response to a physical stress, the lack of ESR1 caused the vaginal epithelium to deteriorate due to the absence of a protective cornified layer and a reduction in keratin production. In the absence of ESR1 in the vaginal epithelial tissue, we also observed an excess of neutrophil infiltration, regardless of the estrous cycle stage. The histological presence of neutrophils was found to correlate with persistent enzymatic activity in the cervical-vaginal fluid. Together, these findings suggest that ESR1 activity in the vaginal epithelial cells is required to maintain proper structural integrity of the vagina and immune response, both of which are necessary for protecting the vagina against physical damage and resetting the vaginal environment.

Opisthorchiasis-Induced Cholangiocarcinoma: How Innate Immunity May Cause Cancer

Innate, inflammatory responses towards persistent Opisthorchis viverrini (OV) infection are likely to contribute to the development of cholangiocarcinoma (CCA), a liver cancer that is rare in the West but prevalent in Greater Mekong Subregion countries in Southeast Asia. Infection results in the infiltration of innate immune cells into the bile ducts and subsequent activation of inflammatory immune responses that fail to clear OV but instead may damage local tissues within the bile ducts. Not all patients infected with OV develop CCA, and so tumourigenesis may be dependent on multiple factors including the magnitude of the inflammatory response that is activated in infected individuals. The purpose of this review is to summarize how innate immune responses may promote tumourigenesis following OV infection and if such responses can be used to predict CCA onset in OV-infected individuals. It also hypothesizes on the role that Helicobacterspp., which are associated with liver fluke infections, may play in activation of the innate the immune system to promote tissue damage and persistent inflammation leading to CCA.

Hypermethylation of the CHRDL1 promoter induces proliferation and metastasis by activating Akt and Erk in gastric cancer

CHRDL1 (Chordin-like 1) is a secreted protein that acts as an antagonist of bone morphogenetic protein (BMP). BMP plays a role as an activator of BMP receptor II (BMPR II), which mediates extracellular to intracellular signal transmission and is involved in carcinogenesis and metastasis. Herein, we report that CHRDL1 expression was significantly down-regulated in gastric cancer tissues and associated with poor survival. Clinic-pathological parameters demonstrated a close relationship between low CHRDL1 expression and metastasis. In vitro, CHRDL1 knockdown promoted tumor cell proliferation and migration through BMPR II by activating Akt, Erk and β-catenin. Furthermore, we observed the hypermethylation of the CHRDL1 promoter in gastric cancer, which induced low expression of CHRDL1 and decreased its secretion to the supernatant. Finally, in vivo experiments confirmed that CHRDL1 acted as a tumor suppressor gene in suppressing tumor growth and metastasis.

Male non-insulin users with type 2 diabetes mellitus are predisposed to gastric corpus-predominant inflammation after H. pylori infection

BACKGROUND

Both H. pylori infection and diabetes increase the risk of gastric cancer. This study investigated whether patients with type 2 diabetes mellitus (T2DM) and H. pylori infection had more severe corpus gastric inflammation and higher prevalence of precancerous lesions than non-diabetic controls.

METHODS

A total of 797 patients with type 2 diabetes mellitus were screened for H. pylori, of whom 264 had H. pylori infection. Of these patients, 129 received esophagogastroduodenoscopy to obtain topographic gastric specimens for gastric histology according to the modified Updated Sydney System, corpus-predominant gastritis index (CGI), Operative Link on Gastritis Assessment, and Operative Link on Gastric Intestinal Metaplasia Assessment. Non-diabetic dyspeptic patients who had H. pylori infection confirmed by esophagogastroduodenoscopy were enrolled as controls.

RESULTS

The male as well as total T2DM patients had higher acute/chronic inflammatory and lymphoid follicle scores in the corpus than non-diabetic controls (p < 0.05). In contrast, the female T2DM patients had higher chronic inflammatory scores in the antrum than the controls (p < 0.05). In T2DM patients, the males had significantly higher rates of CGI than the females (p < 0.05). Multivariate logistic regression analysis showed that male patients (odds ratio: 2.28, 95% confidence interval: 1.11-4.69, p = 0.025) and non-insulin users (odds ratio: 0.33, 95% confidence interval: 0.15-0.74, p = 0.007) were independent factors for the presence of CGI in the H. pylori-infected patients with type 2 diabetes mellitus.

CONCLUSIONS

Patients with type 2 diabetes mellitus and H. pylori infection had more severe corpus gastric inflammation than non-diabetic controls. Moreover, male gender and non-insulin users of T2DM patients were predisposed to have corpus-predominant gastritis after H. pylori infection.

TRIAL REGISTRATION

ClinicalTrial: NCT02466919 , retrospectively registered may 17, 2015.