Deregulation of annexin-A1 and galectin-1 expression in precancerous gastric lesions: intestinal metaplasia and gastric ulcer

Cancer Stem Cells in Tumor Microenvironment of Adenocarcinoma of the Stomach, Colon, and Rectum

Simple Summary

Gastrointestinal cancers have a high mortality rate worldwide, and the progression of the disease is related to cancer stem cells. Until now, its relationship with the microenvironment has been poorly understood. We describe the molecules and different pathways activated during this interaction and the new targeting therapies for cancer cells and microenvironment modulation. This approach could impact the way gastrointestinal cancers are managed.

Abstract

Gastrointestinal adenocarcinomas are one of the world’s deadliest cancers. Cancer stem cells and the tissue microenvironment are highly regulated by cell and molecular mechanisms. Cancer stem cells are essential for maintenance and progression and are associated with resistance to conventional treatments. This article reviews the current knowledge of the role of the microenvironment during the primary establishment of gastrointestinal adenocarcinomas in the stomach, colon, and rectum and its relationship with cancer stem cells. We also describe novel developments in cancer therapeutics, such as targeted therapy, and discuss the advantages and disadvantages of different treatments for improving gastrointestinal cancer prognosis.

Therapeutic effects of hydro-alcoholic extract of Achillea wilhelmsii C. Koch on indomethacin-induced gastric ulcer in rats: a proteomic and metabolomic approach

BACKGROUND

Gastric ulcer is one of the most prevalent diseases worldwide. In Iranian folk medicine, Achillea wilhelmsii (AW) is used as a treatment for gastric ulcer. Previous reports also mentioned Antiulcerogenic properties for this herbal plant. This study investigated the therapeutic effects of Achillea wilhelmsii C. Koch extract on indomethacin-induced gastric lesion in rats, from both proteomic and metabolomic perspectives.

METHODS

The rats were divided into 4 groups. Gastric ulceration was induced by a single dose of indomethacin (45 mg/kg) by oral gavage. An amount of 800 mg/kg of AW extract was administered orally. Serum and tissue samples were collected for further investigations. The metabolomic study was performed by 1H-NMR CPMG spectrometry. Proteomic analysis was also executed by using two dimensional gel electrophoresis (2DE) followed by liquid chromatography coupled to tandem mass spectrometry (LC-ESI/MS/MS). Real time PCR was used to confirm some of the genes.

RESULTS

The macroscopic and microscopic investigations confirmed the effectiveness of the AW extract. There was a panel of metabolites which showed alteration during gastric lesion development. The levels of some of these metabolite reversed nearly to their control values after the administration of AW extract. There were also changes in the levels of some proteins including Alb, Fabp5, Hspb1, Tagln, Lgals7, Csta and Myl9 which were reversed after AW administration.

CONCLUSIONS

Our findings suggested that Achillea wilhelmsii C. Koch extract could be a potential therapy to be used for indomethacin-induced gastric lesion treatment in the future. However, further investigations are needed to confirm the results.

Expression profiles of Annexin A1, formylated peptide receptors and cyclooxigenase-2 in gastroesophageal inflammations and neoplasias

The anti-inflammatory protein Annexin-A1 (ANXA1) is associated to tumor invasion process and its actions can be mediated by formylated peptides receptors (FPRs). Therefore, we evaluated the expression and correlation of ANXA1, FPR and cyclooxygenase-2 (COX-2) enzyme in esophageal and stomach inflammations and neoplasias. The study of proteins was performed by immunohistochemistry in biopsies of esophagitis, Barrett's esophagus, squamous cell carcinoma and adenocarcinoma of the esophagus, as well as gastritis, stomach polypus and gastric adenocarcinoma. The intensity of the expressions was evaluated by densitometry. The immunohistochemical and densitometric analyzes showed specificity for the FPR1 receptor and modulation of the ANXA1, COX-2 and FPR1 expressions in the epithelial cells in the different studied conditions. Increased immunoreactivity of these proteins was observed in cases of inflammation and stomach polypus. Interestingly, moderate immunoreactivity for ANXA1 and FPR1 but increased immunolabeling for COX-2 were observed in Barrett́s esophagus and esophageal adenocarcinomas. Also, there was reduced expression of ANXA1 and FPR1 in esophageal carcinoma but COX-2 overexpression in this tumor. There was no expression of FPR2 but ANXA1 and FPR1 expressions were positively correlated in all clinical conditions studied. Positive correlation between ANXA1 and COX-2 were also observed in inflammation conditions while negative correlation between ANXA1 and COX-2 was observed in esophageal carcinoma. Our results demonstrate the unregulated expression of ANXA1 and COX-2 in precursor lesions of esophageal and stomach cancers, reinforcing their involvement in gastroesophageal carcinogenesis. In addition, the data show that the actions of ANXA1 in the inflammatory and neoplastic processes of the esophagus and stomach are specifically mediated by the FPR1 receptor.

Contribution of galectin-1, a glycan-binding protein, to gastrointestinal tumor progression

Gastrointestinal cancer is a group of tumors that affect multiple sites of the digestive system, including the stomach, liver, colon and pancreas. These cancers are very aggressive and rapidly metastasize, thus identifying effective targets is crucial for treatment. Galectin-1 (Gal-1) belongs to a family of glycan-binding proteins, or lectins, with the ability to cross-link specific glycoconjugates. A variety of biological activities have been attributed to Gal-1 at different steps of tumor progression. Herein, we summarize the current literature regarding the roles of Gal-1 in gastrointestinal malignancies. Accumulating evidence shows that Gal-1 is drastically up-regulated in human gastric cancer, hepatocellular carcinoma, colorectal cancer and pancreatic ductal adenocarcinoma tissues, both in tumor epithelial and tumor-associated stromal cells. Moreover, Gal-1 makes a crucial contribution to the pathogenesis of gastrointestinal malignancies, favoring tumor development, aggressiveness, metastasis, immunosuppression and angiogenesis. We also highlight that alterations in Gal-1-specific glycoepitopes may be relevant for gastrointestinal cancer progression. Despite the findings obtained so far, further functional studies are still required. Elucidating the precise molecular mechanisms modulated by Gal-1 underlying gastrointestinal tumor progression, might lead to the development of novel Gal-1-based diagnostic methods and/or therapies.

Annexin A1: shifting the balance towards resolution and repair

Epithelial barriers play an important role in regulating mucosal homeostasis. Upon injury, the epithelium and immune cells orchestrate repair mechanisms that re-establish homeostasis. This process is highly regulated by protein and lipid mediators such as Annexin A1 (ANXA1). In this review, we focus on the pro-repair properties of ANXA1.

FPR2 promotes invasion and metastasis of gastric cancer cells and predicts the prognosis of patients

Formyl peptide receptor 2 (FPR2), a classical chemoattractant receptor of G-protein-coupled receptors, is reported to be involved in invasion and metastasis of some cancers, but the role of FPR2 in gastric cancer (GC) has not yet been elucidated. In this study, we found that the levels of FPR2 expression in GC were positively correlated with invasion depth, lymph node metastasis and negatively correlated with the patients’ overall survival. Multivariate analysis indicated that FPR2 expression was an independent prognostic marker for GC patients. FPR2-knockdown significantly abrogated the migration and invasion stimulated by Hp(2–20) and Ac(2–26), two well-characterized ligands for FPR2 in GC cells. FPR2 deletion also reduced the tumorigenic and metastatic capabilities of GC cells in vivo. Mechanistically, stimulation with FPR2 ligands resulted in down-regulation of E-cadherin and up-regulation of vimentin, which were reversed by FPR2 knock-down, implying the involvement of epithelial–mesenchymal transition (EMT). Moreover, the activation of FPR2 was accompanied with ERK1/2 phosphorylation, which could be attenuated by FPR2 silencing or treatment with MEK inhibitor, PD98059. Altogether, our results demonstrate that FPR2 is functionally involved in invasion and metastasis, and potentially acts as a novel prognostic marker as well as a potential therapeutic target in human GC.

Annexin A2 and alpha actinin 4 expression correlates with metastatic potential of primary endometrial cancer

The prediction of lymph node metastasis using clinic-pathological data and molecular information from endometrial cancers lacks accuracy and is therefore currently not routinely used in patient management. Consequently, although only a small percentage of patients with endometrial cancers suffer from metastasis, the majority undergo radical surgery including removal of pelvic lymph nodes. Upon analysis of publically available data and published research, we compiled a list of 60 proteins having the potential to display differential abundance between primary endometrial cancers with versus those without lymph node metastasis. Using data dependent acquisition LC-ESI-MS/MS we were able to detect 23 of these proteins in endometrial cancers, and using data independent LC-ESI-MS/MS the differential abundance of five of those proteins was observed. The localization of the differentially expressed proteins, was visualized using peptide MALDI MSI in whole tissue sections as well as tissue microarrays of 43 patients. The proteins identified were further validated by immunohistochemistry. Our data indicate that annexin A2 protein level is upregulated, whereas annexin A1 and α actinin 4 expression are downregulated in tumours with lymph node metastasis compared to those without lymphatic spread. Moreover, our analysis confirmed the potential of these markers, to be included in a statistical model for prediction of lymph node metastasis. The predictive model using highly ranked m/z values identified by MALDI MSI showed significantly higher predictive accuracy than the model using immunohistochemistry data. In summary, using publicly available data and complementary proteomics approaches, we were able to improve the prediction model for lymph node metastasis in EC.

What gastric cancer proteomic studies show about gastric carcinogenesis?

Gastric cancer is a complex, heterogeneous, and multistep disease. Over the past decades, several studies have aimed to determine the molecular factors that lead to gastric cancer development and progression. After completing the human genome sequencing, proteomic technologies have presented rapid progress. Differently from the relative static state of genome, the cell proteome is dynamic and changes in pathologic conditions. Proteomic approaches have been used to determine proteome profiles and identify differentially expressed proteins between groups of samples, such as neoplastic and nonneoplastic samples or between samples of different cancer subtypes or stages. Therefore, proteomic technologies are a useful tool toward improving the knowledge of gastric cancer molecular pathogenesis and the understanding of tumor heterogeneity. This review aimed to summarize the proteins or protein families that are frequently identified by using high-throughput screening methods and which thus may have a key role in gastric carcinogenesis. The increased knowledge of gastric carcinogenesis will clearly help in the development of new anticancer treatments. Although the studies are still in their infancy, the reviewed proteins may be useful for gastric cancer diagnosis, prognosis, and patient management.

Interaction between inflammatory mediators and miRNAs in Helicobacter pylori infection

Helicobacter pylori cause chronic inflammation favouring gastric carcinogenesis, and its eradication may prevent malignant transformation. We evaluated whether H. pylori infection and its eradication modify the expression of inflammatory mediators in patients with chronic gastritis. Furthermore, we assessed whether microRNAs modulate inflammatory pathways induced by H. pylori and identified miRNA–gene interaction networks. mRNA and protein expression of TNFA, IL6, IL1B, IL12A, IL2 and TGFBRII and miRNAs miR‐103a‐3p, miR‐181c‐5p, miR‐370‐3p, miR‐375 and miR‐223‐3p were evaluated in tissue samples from 20 patients with chronic gastritis H. pylori negative (Hp−) and 31 H. pylori positive (Hp+), before and three months after bacterium eradication therapy, in comparison with a pool of Hp− normal gastric mucosa. Our results showed that H. pylori infection leads to up‐regulation of TNFA, IL6, IL12A and IL2 and down‐regulation of miRNAs. Bacterium eradication reduces the expression of TNFA and IL6 and up‐regulates TGFBRII and all investigated miRNAs, except miR‐223‐3p. Moreover, transcriptional profiles of inflammatory mediators and miRNAs after eradication are different from the non‐infected group. Deregulated miRNA–mRNA interaction networks were observed in the Hp+ group before and after eradication. Therefore, miRNAs modulated cytokine expression in the presence of H. pylori and after its eradication, suggesting that miRNAs participate in the pathological process triggered by H. pylori in the gastric mucosa.

Immunohistochemical Studies on Galectin Expression in Colectomised Patients with Ulcerative Colitis

Introduction. The aetiology and pathogenesis of ulcerative colitis (UC) are essentially unknown. Galectins are carbohydrate-binding lectins involved in a large number of physiological and pathophysiological processes. Little is known about the role of galectins in human UC. In this immunohistochemical exploratory study, both epithelial and inflammatory cell galectin expression were studied in patients with a thoroughly documented clinical history and were correlated with inflammatory activity. Material and Methods. Surgical whole intestinal wall colon specimens from UC patients (n = 22) and controls (n = 10) were studied. Clinical history, pharmacological treatment, and modified Mayo-score were recorded. Tissue inflammation was graded, and sections were stained with antibodies recognizing galectin-1, galectin-2, galectin-3, and galectin-4. Results. Galectin-1 was undetectable in normal and UC colonic epithelium, while galectin-2, galectin-3, and galectin-4 were strongly expressed. A tendency towards diminished epithelial expression with increased inflammatory grade for galectin-2, galectin-3, and galectin-4 was also found. In the inflammatory cells, a strong expression of galectin-2 and a weak expression of galectin-3 were seen. No clear-cut correlation between epithelial galectin expression and severity of the disease was found. Conclusion. Galectin expression in patients with UC seems to be more dependent on disease focality and individual variation than on degree of tissue inflammation.

Effects of Two Common Polymorphisms rs2910164 in miR-146a and rs11614913 in miR-196a2 on Gastric Cancer Susceptibility

Background. Single nucleotide polymorphisms (SNPs) in genes encoding microRNAs may play important role in the development of gastric cancer. It has been reported that common SNPs rs2910164 in miR-146a and rs11614913 in miR-196a2 are associated with susceptibility to gastric cancer. The published results remain inconclusive or even controversial. A meta-analysis was conducted to quantitatively assess potential association between the two common SNPs and gastric cancer risk. Methods. A comprehensive literature search was performed in multiple internet-based electronic databases. Data from 12 eligible studies were extracted to estimate pooled odds ratios (ORs) and 95% confidence intervals (95% CI). Results. C allele of rs2910164 is associated with reduced gastric cancer risk in heterozygote model and dominant model whereas rs11614913 indicates no significant association. Subgroup analysis demonstrates that C allele of rs2910164 and rs11614913 may decrease susceptibility to diffuse type gastric cancer in dominant model and recessive model, respectively, while rs11614913 increased intestinal type gastric cancer in dominant model. Conclusion. SNPs rs2910164 and rs11614913 might have effect on gastric cancer risk in certain genetic models and specific types of cancer. Further well-designed studies should be considered to validate the potential effect.

Effect of Helicobacter pylori eradication on TLR2 and TLR4 expression in patients with gastric lesions

Objective. Helicobacter pylori (Hp) is recognized by TLR4 and TLR2 receptors, which trigger the activation of genes involved in the host immune response. Thus, we evaluated the effect of eradication therapy on TLR2 and TLR4 mRNA and protein expression in H. pylori-infected chronic gastritis patients (CG-Hp+) and 3 months after treatment. Methods. A total of 37 patients CG-Hp+ were evaluated. The relative quantification (RQ) of mRNA was assessed by TaqMan assay and protein expression by immunohistochemistry. Results. Before treatment both TLR2 and TLR4 mRNA in CG-Hp+ patients were slightly increased (TLR2 = 1.32; TLR4 = 1.26) in relation to Hp-negative normal gastric mucosa (P ≤ 0.05). After successful eradication therapy no significant change was observed (TLR2 = 1.47; TLR4 = 1.53; P > 0.05). In addition, the cagA and vacA bacterial genotypes did not influence the gene expression levels, and we observed a positive correlation between the RQ values of TLR2 and TLR4, both before and after treatment. Immunoexpression of the TLR2 and TLR4 proteins confirmed the gene expression results. Conclusion. In conclusion, the expression of both TLR2 and TLR4 is increased in CG-Hp+ patients regardless of cagA and vacA status and this expression pattern is not significantly changed after eradication of bacteria, at least for the short period of time evaluated.

Increased expression of annexin A1 predicts poor prognosis in human hepatocellular carcinoma and enhances cell malignant phenotype

Annexin A1 (ANXA1) belongs to the annexin superfamily of proteins, which contribute to the pathological consequence and sequelae of most serious human diseases. Recent studies have reported diverse roles of ANXA1 in various human cancers; however, its involvement in human hepatocellular carcinoma (HCC) still remains controversial. To investigate the expression pattern of ANXA1 in HCC tissues and evaluate its associations with tumor progression and patients' prognosis, immunohistochemistry was performed using 160 pairs of formalin-fixed and paraffin-embedded cancerous and adjacent non-cancerous tissues from patients with HCC. Then, the associations between ANXA1 expression, clinicopathological characteristics, and prognosis of HCC patients were statistically evaluated. In vitro migration and invasion assays of siRNA-targeted ANXA1-transfected cells were further performed. As a result, the expression levels of ANXA1 protein in HCC tissues were significantly higher than those in adjacent non-cancerous tissues (P < 0.001). High ANXA1 expression was closely correlated with advanced TNM stage (P = 0.001) and high Edmondson grade (P = 0.02). Then, univariate and multivariate analyses showed that the status of ANXA1 expression was an independent predictor for overall survival of HCC patients. Furthermore, knockdown of ANXA1 by transfection of siRNA-ANXA1 could suppress the migration and invasion abilities of HCC cells in vitro. Collectively, these findings offer the convincing evidence that ANXA1 may play an important role in HCC progression and can be used as a molecular marker to predict prognosis and a potential target for therapeutic intervention of HCC.