Genetic Mechanisms and Aberrant Gene Expression during the Development of Gastric Intestinal Metaplasia and Adenocarcinoma

Linking dysbiosis to precancerous stomach through inflammation: Deeper than and beyond imaging

Upper gastrointestinal endoscopy is considered the gold standard for gastric lesions detection and surveillance, but it is still associated with a non-negligible rate of missing conditions. In the Era of Personalized Medicine, biomarkers could be the key to overcome missed lesions or to better predict recurrence, pushing the frontier of endoscopy to functional endoscopy. In the last decade, microbiota in gastric cancer has been extensively explored, with gastric carcinogenesis being associated with progressive dysbiosis. Helicobacter pylori infection has been considered the main causative agent of gastritis due to its interference in disrupting the acidic environment of the stomach through inflammatory mediators. Thus, does inflammation bridge the gap between gastric dysbiosis and the gastric carcinogenesis cascade and could the microbiota-inflammation axis-derived biomarkers be the answer to the unmet challenge of functional upper endoscopy? To address this question, in this review, the available evidence on the role of gastric dysbiosis and chronic inflammation in precancerous conditions of the stomach is summarized, particularly targeting the nuclear factor-κB (NF-κB), toll-like receptors (TLRs) and cyclooxygenase-2 (COX-2) pathways. Additionally, the potential of liquid biopsies as a non-invasive source and the clinical utility of studied biomarkers is also explored. Overall, and although most studies offer a mechanistic perspective linking a strong proinflammatory Th1 cell response associated with, but not limited to, chronic infection with Helicobacter pylori, promising data recently published highlights not only the diagnostic value of microbial biomarkers but also the potential of gastric juice as a liquid biopsy pushing forward the concept of functional endoscopy and personalized care in gastric cancer early diagnosis and surveillance.

EXOC4 Promotes Diffuse-Type Gastric Cancer Metastasis via Activating FAK Signal

In comparison with intestinal-type gastric cancer, diffuse-type gastric cancer (DGC) is more likely to recur, metastasize, and exhibit worse clinical outcomes; however, the underlying mechanism of DGC recurrence remains elusive. By employing an LC/MS-MS proteomic approach, we identified that exocyst complex component 4 (EXOC4) was significantly upregulated in DGC with recurrence, compared to those with nonrecurrence. High expression of EXOC4 was correlated with tumor metastasis and poor prognosis in patients with DGC. Moreover, EXOC4 promoted cell migration and invasion as well as the tumor metastasis of DGC cells. Mechanistically, EXOC4 regulated the phosphorylation of focal adhesion kinase (FAK) at Y397 sites by stimulating the secretion of integrin α5/β1/EGF and enhancing the interaction of FAK and integrin or EGFR. The FAK inhibitor VS-4718 reversed the metastasis mediated by EXOC4 overexpression and suppressed the tumor growth of patient-derived xenografts derived from DGC with high EXOC4 expression. The EXOC4-FAK axis could be a potential therapeutic target for patients with DGC with high expression of EXOC4.

IMPLICATIONS

The EXOC4-FAK axis promoted DGC metastasis and could be a potential therapeutic target for patients with DGC.

Tumor Molecular Profiling in Hispanics: Moving Towards Precision Oncology and Health Equity

BACKGROUND

Tumor molecular profiling techniques, such as next-generation sequencing (NGS) to identify somatic genetic alterations, allow physicians to have a better understanding of the affected carcinogenic pathways and guide targeted therapy. The objective of our study was to characterize common somatic alterations and carcinogenic pathways among Puerto Rican Hispanics with solid tumors.

METHODS

We conducted a single-institution, retrospective study to characterize molecular tumor profiles using a 592-gene NGS platform. Actionable mutations with current or developing therapies targeting affected genes/pathways were highlighted.

RESULTS

Tumors from 50 Hispanic patients were evaluated using CARIS Life Science© NGS testing. The median age of our study population was 55 (range 21-84); 54% (n = 27) were males. The primary tumor sites were colorectal (n = 24), gastric (n = 5), breast (n = 4), and lung (n = 3). The most common genetic mutations identified were in TP53 (44%), APC (38%), and KRAS (32%); followed by alterations in EGFR (4%), HER2 (6%), and homologous recombinant deficiency genes (BRCA2, 6%). Genetic alterations were found in multiple signaling pathways particularly in the cell cycle control pathway, MAPK and Wnt/β-Catenin signaling pathways. Targetable biomarkers were identified in 27/50 (54.0%) of tumors.

DISCUSSION

Molecular profiling techniques, such as next-generation sequencing, have substantially expanded access to alterations in the cancer genome. Our findings demonstrated important actionable mutations in most of the tumors evaluated and support the integration of somatic mutation profiling in the evaluation of Hispanic cancer patients with advanced cancer to help guide therapeutic options.

Trefoil Factor 3 Inhibits Thyroid Cancer Cell Progression Related to IL-6/JAK/STAT3 Signaling Pathway

Objectives

Abnormal expression of trefoil factor 3 (TFF3) in breast, stomach, and colon tumors may be related to the occurrence of tumors, suggesting its role in angiogenesis. In this study, the aim was to explore the role of TFF3 in thyroid cancer.

Methods

TFF3 expression analysis was performed via GEPIA and RT-PCR. To explore the effects of TFF3 on thyroid cancer cell motility, cell function assays were performed. Furthermore, GSEA pathway analysis and western blot were used to explore the mechanism by which TFF3 represses the progression of thyroid cancer cells.

Results

Here, we showed that low expression level of TFF3 in thyroid cancer is related to thyroid cancer nodal metastasis. The patients with low TFF3 expression showed worse disease-free survival than those with high level of TFF3. Underexpressed TFF3 increased cell motility and inhibited cell apoptosis. We found that the levels of IL-6, p-JAK2/JAK2, and pSTAT3/STAT3 were inhibited in the pcDNA-TFF3 group compared to the pcDNA-NC group and these factors were upregulated in the si-TFF3 group compared to the si-NC group in BCPAP and TPC-1 cells.

Conclusion

TFF3 inhibits thyroid cancer cell progression related to IL-6/JAK/STAT3 signaling pathway.

Meta-Analysis Reveals the Prognostic Relevance of Nuclear and Membrane-Associated Bile Acid Receptors in Gastric Cancer

INTRODUCTION

Bile acids (BAs) arising from duodenogastric reflux are known to facilitate gastric cancer (GC) development. Although BAs traditionally contribute to carcinogenesis through direct cellular cytotoxicity, increasing evidence implicates nuclear and membrane BA receptors (BARs) as additional factors influencing cancer risk. Indeed, some BARs are already linked with GC, but conflicting evidence and lack of information regarding other endogenous BARs warrant further investigation. In this study, we meta-analyzed multiple data sets to identify clinically relevant relationships between BAR expression and prognosis, clinicopathology, and activity in GC.

METHODS

We collected transcriptomic data from the Gene Expression Omnibus and The Cancer Genome Atlas to analyze associations between BAR expression and GC prognosis, subtype, and clinicopathology. We also used Ingenuity Pathway Analysis to assess and predict functions, upstream regulators, and downstream mediators of membrane and nuclear BARs in GC.

RESULTS

BARs showed differential distribution in GC; membrane BARs (G protein-coupled BAR 1, sphingosine-1-phosphate receptor 2, and cholinergic receptor muscarinic 2) were enriched in diffuse-, genome-stable, and mesenchymal-type tumors, whereas nuclear BARs (pregnane-X-receptor, constitutive androstane receptor, and farnesoid-X-receptor) were enriched in chromosome instability and metabolic subtypes. High expression of all membrane but not nuclear BARs was associated with poor prognosis and unfavorable GC clinicopathologic features. Similarly, expression patterns of membrane but not nuclear BARs varied geographically, aligning with Helicobacter pylori infection and GC mortality rates. Finally, GC-related oncogenes, namely transforming growth factor β1, were associated with membrane BARs, whereas many metabolic-associated genes were associated with nuclear BARs.

DISCUSSION

Through transcriptomic meta-analysis, we identified distinct expression profiles between nuclear and membrane BARs that demonstrate prognostic relevance and warrant further investigation.

African flora has the potential to fight multidrug resistance of cancer

Background. Continuous efforts from scientists of diverse fields are necessary not only to better understand the mechanism by which multidrug-resistant (MDR) cancer cells occur, but also to boost the discovery of new cytotoxic compounds to fight MDR phenotypes. Objectives. The present review reports on the contribution of African flora in the discovery of potential cytotoxic phytochemicals against MDR cancer cells. Methodology. Scientific databases such as PubMed, ScienceDirect, Scopus, Google Scholar, and Web of Knowledge were used to retrieve publications related to African plants, isolated compounds, and drug resistant cancer cells. The data were analyzed to highlight cytotoxicity and the modes of actions of extracts and compounds of the most prominent African plants. Also, thresholds and cutoff points for the cytotoxicity and modes of action of phytochemicals have been provided. Results. Most published data related to the antiproliferative potential of African medicinal plants were from Cameroon, Egypt, Nigeria, or Madagascar. The cytotoxicity of phenolic compounds isolated in African plants was generally much better documented than that of terpenoids and alkaloids. Conclusion. African flora represents an enormous resource for novel cytotoxic compounds. To unravel the full potential, efforts should be strengthened throughout the continent, to meet the challenge of a successful fight against MDR cancers.

Anti-carcinogenic effects of the phenolic-rich extract from abnormal Savda Munziq in association with its cytotoxicity, apoptosis-inducing properties and telomerase activity in human cervical cancer cells (SiHa)

BACKGROUND

Abnormal Savda Munziq (ASMq) is a herbal preparation used in Traditional Uighur Medicine for the treatment cancer. The polyphenol is main compounds contained in ASMq preparation responsible for anticancer effect of ASMq.

METHODS

In this study,Real-time quantitative Polymerase Chain Reaction (RT-PCR) assay, MTT assay and flow cytometry were used to investigate the effect of polyphenol of ASMq on cell viability and the potential of the phenolic rich extracts of ASMq to induce apoptosis in human cervical cancer cells SiHa and its effects on telomerase activity were investigated. Cellular morphological change was observed by phase contrast microscopy. The MTT cell viability data revealed that treatment with phenolic rich extracts at 75 ~ 175 μg/ml significantly inhibited the viability and proliferation of cells, and these effects occurred in a concentration-dependent manner and time dependent manner (P < 0.01).

RESULTS

The phenolic rich extracts can induce apoptosis of SiHa cells, can increase the apoptosis rate in a concentration-dependent manner and time dependent manner (P < 0.01). Growth inhibition and apoptosis induction by phenolic rich extracts treatment on SiHa cells was associated with down-regulation of anti-apoptotic Bcl-2 expression and telomerase (P < 0.05) and Survivin expression. In addition, phenolic rich extracts exerted a dose-dependent induction of FHIT expression.

CONCLUSION

These results suggest that phenolic rich extracts may have anti-tumor effects in human cervical cancer through cytotoxicity, apoptosis-inducing properties and telomerase activity.

Mutually exclusive FGFR2, HER2, and KRAS gene amplifications in gastric cancer revealed by multicolour FISH

Gastric cancer (GC) is a major cause of global cancer mortality. Previous genomic studies have reported that several RTK-RAS pathway components are amplified in GC, with individual tumours often amplifying one component and not others ("mutual exclusivity"). Here, we sought to validate these findings for three RTK/RAS components (FGFR2, HER2, KRAS) using fluorescence in situ hybridisation (FISH) on a series of gastric tumours, cell lines and patient-derived xenografts. Applying dual-colour FISH on 137 gastric tumours (89 FFPE surgical resections and 48 diagnostic biopsies), we observed FGFR2 amplification in 7.3% and HER2 amplification in 2.2% of GCs. GCs exhibiting FGFR2 amplification were associated with high tumour grade (p = 0.034). In FISH positive tumours, striking differences in copy number levels between cancer cells in the same tumour were observed, suggesting intra-tumour heterogeneity. Using a multicolour FISH assay allowing simultaneous detection of FGFR2, HER2, and KRAS amplifications, we confirmed that these components exhibited a mutually exclusive pattern of gene amplification across patients. The FISH data were also strongly correlated with Q-PCR levels and at the protein level by immunohistochemistry. Our data confirm that RTK/RAS components are mutually exclusively amplified in GC, and demonstrate the feasibility of identifying multiple aneuploidies using a single FISH assay. Application of this assay to GC samples, particularly diagnostic biopsies, may facilitate enrollment of GC patients into clinical trials evaluating RTK/RAS directed therapies. However, the presence of intra-tumour heterogeneity may require multiple biopsy samples to be obtained per patient before a definitive diagnosis can be attained.

OCT-1 overexpression is associated with poor prognosis in patients with well-differentiated gastric cancer

Octamer transcription factor-1 (OCT-1) is a well-known transcription factor that is reportedly overexpressed in intestinal metaplasia and gastric carcinoma in the intestine. In this study, we investigated OCT-1 overexpression as a prognostic factor for gastric cancer. The association between OCT-1 overexpression (detected using immunohistochemistry) and clinicopathological features including survival was evaluated. In vitro gain-of-function approaches were utilized to assess the function of OCT-1 in malignancy. Analysis of OCT-1 expression in patients with gastric cancer with well-differentiated carcinoma as per the World Health Organization classification showed that OCT-1 overexpression was correlated with advanced tumor invasion (58.8 % of patients with advanced tumor invasion vs. 21.2 % of patients with early tumor invasion; p<0.01), lymph node metastasis (63.9 % of patients with metastasis vs. 24.1 % of those without; p=0.015), and cancer recurrence (83.3 % of patients with recurrence vs. 25.4 % of those without; p<0.01), as well as a lower survival rate (62.8 vs. 87.9 Mo; p<0.01). However, there were no significant differences in the levels of OCT-1 expression in gastric cancer patients with other carcinoma types (p>0.05). Furthermore, we found that the proliferation rate of OCT-1-overexpressing MKN-45 cells was higher than that of the control cells. OCT-1 overexpression may be a marker for poor prognosis in patients with well-differentiated gastric adenocarcinoma.

The inhibitory effect of a novel polypeptide fraction from Arca subcrenata on cancer-related inflammation in human cervical cancer HeLa cells

Inflammation is known to be closely associated with the development of cancer. The study was launched in human cervical cancer HeLa cells to investigate the antitumor and anti-inflammatory effects of P2, a marine polypeptide fraction from an important fishery resource Arca subcrenata. The basic research showed that P2 could suppress the production of nitric oxide in LPS-induced RAW264.7 macrophage cells as well as the secretion of inflammatory cytokines IL-6 and TNF- α in human cervical cancer HeLa cells. For the molecular mechanisms, P2 was shown to downregulate the gene expression of proinflammatory cytokines IL-6 and IL-8 and to inhibit the COX-2 and iNOS-related pathways in HeLa cells. In consequence, P2 might inhibit tumor development by blocking the interaction between tumor microenvironment and proinflammatory mediators. All findings indicate that P2 possesses the potential to be developed as a novel agent for cancer therapy.

SATB1 expression in gastric mucosa in relation to Helicobacter pylori infection and family history of gastric cancer

PURPOSE

SATB1 protein, the altered levels of which are observed in tumour tissues, acts as a global regulator of gene expression. The aim of the study was to investigate the expression level of the SATB1 gene in gastric mucosa of dyspeptic patients in relation to the H. pylori infection, the family history of gastric cancer (FHGC), and histopathological changes.

MATERIAL AND METHODS

The study comprised 64 patients with dyspeptic symptoms. Group I - 28 control patients (10 H.pylori positive) without the FHGC. Group II - 36 patients (16 H. pylori positive) with the FHGC. The samples with normal mucosa (NM) or chronic superficial gastritis (CSG) were used for further analysis. qRT-PCR was used to determine the level of mRNA of SATB1.

RESULTS

The dominant histopathological changes in group I were NM and CSG. Specimens from group II have demonstrated an increasing frequency of atrophy (A) and intestinal metaplasia (IM). The A and IM specimens have shown increase of expression of the SATB1 and were excluded from further evaluation. In corpus samples of group II patients, the amount of SATB1 mRNA was higher than in antrum samples, regardless of H. pylori infection. The presence of bacterium resulted in the elevated SATB1 expression in corpus samples of group II patients only, while the genetic factor down-regulated SATB1 gene in the antrum samples of the H. pylori negative individuals.

CONCLUSIONS

The expression of SATB1 gene correlates with histological changes and is altered by the selected environmental and hereditary factors, and the observed changes may have an impact on the development of gastric cancer.

An overview of current research of gastric hyperplastic polyps

Gastric hyperplastic polyp (GHP) is one of the most common polypoid lesions of the stomach and has the potential of malignant transformation. This article gives a review of recent progress in research of GHP in terms of clinical and pathological factors, pathogenesis, relation with atypical hyperplasia and canceration, molecular biology and mucin expression.

IL-11 is a parietal cell cytokine that induces atrophic gastritis

BACKGROUND AND AIMS

IL-is important in gastric damage, mucosal repair and gastric cancer progression. We analysed IL-11 expression in H.pylori infected mouse stomach, the site of gastric IL-11 expression in mice and humans, and the effect of exogenous IL-11 on gastric mucosal homeostasis.

METHODS

IL-11 protein was localised in mouse and human stomach. The impact of chronic, exogenous IL-11 on normal mouse stomach was examined histologically and transcriptionally by microarray, confirmed by mRNA and protein analysis. Functional impact of IL-11 on gastric acid secretion was determined.

RESULTS

In mice infected with H.pylori, IL-11 was increased in fundic mucosa with temporal expression similar to IL-1b. IL-11 protein was localised predominantly to parietal cells in mouse and human stomach. Application of exogenous IL-11 to resulted in fundic parietal and chief cell loss, hyperplasia, mucous cell metaplasia and inflammation. Coincident with cellular changes were an increased gastric pH, altered parietal cell ultrastructure and altered gene expression, particularly genes involved in immune response and ion transport which could result in compromised acid secretion. We confirmed that a single dose of IL-11 effectively ablated the gastric response to histamine.

CONCLUSIONS

IL-11 is a parietal cell cytokine that blocks gastric acid secretion, likely via reducing expression of parietal cell ion transport genes, CCKb and histamine H2 receptors. IL-11 expression is increased in H. pylori infected mouse stomach and treatment of wild type mice with IL-11 induced changes in the gastric fundic mucosa reminiscent of chronic atrophic gastritis, a precursor to gastric cancer.

HLA class I: an unexpected role in integrin β4 signaling in endothelial cells

The production of anti-donor antibodies to HLA class I and class II antigens following transplantation is associated with development of transplant vasculopathy and graft loss. Antibodies against HLA class I (HLA-I) molecules are thought to contribute to transplant vasculopathy by triggering signals that elicit the activation and proliferation of endothelial cells. The proximal molecular events that regulate HLA-I dependent signal transduction are not well understood. We demonstrated a mutual dependency between HLA-I and integrin β4 to stimulate signal transduction and cell proliferation. Similarly, we found that integrin β4-mediated cell migration was dependent upon its interactions with HLA-I molecules. Since integrin β4 has been implicated in angiogenesis and tumor formation, associations between integrin β4 and HLA-I may play an important role in cancer. Further characterization of interactions between HLA-I and integrin β4 may lead to the development of therapeutic strategies for the treatment and prevention of chronic allograft rejection and cancer.

Expression patterns of MUC1, MUC2 and MUC3 in gastric hyperplastic polyps Juan Li, Li-Hua Wu, Yan Shi, Yu-Fei Jiao

AIM: To evaluate the expression patterns of MUC1, MUC2 and MUC3 in gastric hyperplastic polyps (GHP) and to analyze their value as markers for judging the malignant potential of GHP.

METHODS: A total of 238 GHP biopsy or surgical specimens, including 188 cases without dysplasia, 35 cases with low grade dysplasia (LGD), 8 cases with high grade dysplasia(HGD), and 7 cases with carcinoma (Ca), were used in this study. Thirty normal gastric mucosal specimens were used as controls. Immunohistochemistry was performed to detect the expression patterns of mucin proteins (MUC1, MUC2 and MUC3) in these specimens.

RESULTS: Cytoplasmic and membranous expression of MUC1 was observed in 85.60% of GHP cases without dysplasia or carcinoma. Glandular luminal expression of MUC1 was observed in 80.0% of GHP cases with LGD and 100% of GHP cases with HGD/Ca. The positive rate of MUC2 expression was 8.11% in GHP, 21.93% in GHP with LGD, and 31.42% in GHP with HGD/Ca. MUC3 expression was detected in one case of GHP with LGD and three cases of GHP with HGD/Ca but not in GHP without dysplasia.

CONCLUSION: MUC1 and MUC2 may be useful markers for judging the malignant potential of GHP.

Anti-carcinogenic effects of sulforaphane in association with its apoptosis-inducing and anti-inflammatory properties in human cervical cancer cells

BACKGROUND

The multistep process of carcinogenesis is characterized by progressive disorganization and occurrence of initiation, promotion, and progression events. Several new strategies such as chemoprevention are being developed for treatment and prevention at various stages of carcinogenesis. Sulforaphane, a potential chemopreventive agent, possesses anti-proliferative, anti-inflammatory, anti-oxidant and anti-cancer activities and has attracted extensive interest for better cancer management.

METHODS

We evaluated the effect of sulforaphane alone or in combination with gemcitabine on HeLa cells by cell viability assay and confirmed the results by apoptosis assay. Further we analyzed the effect of sulforaphane on the expression of Bcl-2, COX-2 and IL-1β by RT-PCR on HeLa cells.

RESULTS

In the present study, sulforaphane was found to induce dose-dependent selective cytotoxicity in HeLa cells in comparison to normal cells pointing to its safe cytotoxicity profile. Additionally, a combination of sulforaphane and gemcitabine was found to increase the growth inhibition in a synergistic manner in HeLa cells compared to the individual drugs. Also, the expression analysis of genes involved in apoptosis and inflammation revealed significant downregulation of Bcl-2, COX-2 and IL-1β upon treatment with sulforaphane.

CONCLUSION

Our results suggest that sulforaphane exerts its anticancer activities via apoptosis induction and anti-inflammatory properties and provides the first evidence demonstrating synergism between sulforaphane and gemcitabine which may enhance the therapeutic index of prevention and/or treatment of cervical cancer.