Epithelial-mesenchymal transition in human gastric cancer cell lines induced by TNF-α-inducing protein of Helicobacter pylori

Biophysics in tumor growth and progression: from single mechano-sensitive molecules to mechanomedicine

Evidence from physical sciences in oncology increasingly suggests that the interplay between the biophysical tumor microenvironment and genetic regulation has significant impact on tumor progression. Especially, tumor cells and the associated stromal cells not only alter their own cytoskeleton and physical properties but also remodel the microenvironment with anomalous physical properties. Together, these altered mechano-omics of tumor tissues and their constituents fundamentally shift the mechanotransduction paradigms in tumorous and stromal cells and activate oncogenic signaling within the neoplastic niche to facilitate tumor progression. However, current findings on tumor biophysics are limited, scattered, and often contradictory in multiple contexts. Systematic understanding of how biophysical cues influence tumor pathophysiology is still lacking. This review discusses recent different schools of findings in tumor biophysics that have arisen from multi-scale mechanobiology and the cutting-edge technologies. These findings range from the molecular and cellular to the whole tissue level and feature functional crosstalk between mechanotransduction and oncogenic signaling. We highlight the potential of these anomalous physical alterations as new therapeutic targets for cancer mechanomedicine. This framework reconciles opposing opinions in the field, proposes new directions for future cancer research, and conceptualizes novel mechanomedicine landscape to overcome the inherent shortcomings of conventional cancer diagnosis and therapies.

The Influence of the Microbiome on Immunotherapy for Gastroesophageal Cancer

Immunotherapy has shown promise as a treatment option for gastroesophageal cancer, but its effectiveness is limited in many patients due to the immunosuppressive tumor microenvironment (TME) commonly found in gastrointestinal tumors. This paper explores the impact of the microbiome on the TME and immunotherapy outcomes in gastroesophageal cancer. The microbiome, comprising microorganisms within the gastrointestinal tract, as well as within malignant tissue, plays a crucial role in modulating immune responses and tumor development. Dysbiosis and reduced microbial diversity are associated with poor response rates and treatment resistance, while specific microbial profiles correlate with improved outcomes. Understanding the complex interactions between the microbiome, tumor biology, and immunotherapy is crucial for developing targeted interventions. Microbiome-based biomarkers may enable personalized treatment approaches and prediction of patient response. Interventions targeting the microbiome, such as microbiota-based therapeutics and dietary modifications, offer the potential for reshaping the gut microbiota and creating a favorable TME that enhances immunotherapy efficacy. Further research is needed to reveal the underlying mechanisms, and large-scale clinical trials will be required to validate the efficacy of microbiome-targeted interventions.

Multiple bioinformatics analysis identifies IGFBP1 as associated with the prognosis of stomach adenocarcinoma

This study aimed to screen the hub gene for predicting the prognosis of patients with stomach adenocarcinoma (STAD). The RNA-sequencing expression data and clinical data of STAD were collected from the cancer genome atlas. The R package "limma" was performed to ascertain the differentially expressed genes (DEGs) between the relapse group and non-relapse group, and the DEGs between the survival dead status group and survival alive status group were screened. The overlapping genes between 2 DEGs sets were identified by the Venn diagram. Many different bioinformatics analysis methods were performed to analyze the importance of hub genes. One gene signature, IGFBP1, was extracted. The KM plot indicated that STAD patients with low IGFBP1 mRNA expression have a shorter overall survival time. The top 100 co-expression genes of IGFBP1 were mainly enriched in complement and coagulation cascades, epithelial cell signaling in Helicobacter pylori infection, and Wnt signaling pathway. Immune infiltration analysis indicated IGFBP1 may inhibit immune cell infiltration in tumors by infiltration and immune escape, leading to tumor metastasis and progression. The bioinformatics analysis results indicate that IGFBP1 can be used as a tool to evaluate the mortality risk of patients with STAD.

Changes in Nucleolin Expression during Malignant Transformation Leading to Ovarian High-Grade Serous Carcinoma

OBJECTIVE

Ovarian high-grade serous carcinoma (HGSC) is a fatal malignancy of women. Alterations in the expression of nuclear proteins are early steps in malignant transformation; nucleolin is one such protein. Changes in nucleolin expression and circulatory levels during ovarian HGSC development are unknown. The study goal was to determine if tissue and circulatory levels of nucleolin change in response to malignant transformation leading to ovarian HGSC.

METHODS

Sera, ovaries, and BRCA+ fimbria from healthy subjects, and sera and tumor tissues from patients (n = 10 each), and healthy hens and hens with HGSC were examined in exploratory and prospective studies for nucleolin expression by immunohistochemistry, immunoblotting, gene expression, and immunoassay, and analyzed by analysis of variance (ANOVA).

RESULTS

Compared with normal, nucleolin expression was higher in patients and hens with ovarian HGSC and in women with a risk of HGSC (P < 0.05). Compared with normal (1400 + 105 pg/mL, n = 8), serum nucleolin levels were 1.5 and 1.7-fold higher in patients with early- (n = 5) and late-stage (n = 5) HGSC, respectively. Additionally, serum nucleolin levels increased significantly (P < 0.05) prior to the formation of detectable masses.

CONCLUSION

This pilot study concluded that tissue and serum levels of nucleolin increase in association with malignant changes in ovaries and fimbriae leading to ovarian HGSC.

TNF-α-inducing protein of Helicobacter pylori promotes EMT and cancer stem-like cells properties via activation of Wnt/β-catenin signaling pathway in gastric cancer cells

Tumor necrosis factor-α-inducing protein (Tipα) is a newly identified toxin, which promotes the inflammation and carcinogenesis caused by Helicobacter pylori (H. pylori). However, its mechanism of pathogenesis is still unclear. To investigate the carcinogenic mechanisms of Tipα, SGC7901 cells and SGC7901-derived cancer stem-like cells (CSCs) were stimulated by recombinant Tipα protein with or without Wnt/β-catenin signaling inhibitor XAV939. qRT-PCR and Western blotting were employed to detect expression of epithelial-mesenchymal transition (EMT), CSCs markers, and downstream target genes of this signaling pathway. The cell migration ability was measured by wound healing assay and transwell assay. Our results indicated that Tipα promoted CSC properties of SGC7901 spheroids, including increased expression of CSC specific surface markers CD44, Oct4, Nanog, and an increased capacity for self-renewal. Tipα activated Wnt/β-catenin signaling in both SGC7901 cells or CSCs. Furthermore, Tipα induced the EMT and increased the expressions of downstream target genes of this signaling, including c-myc, cyclin D1, and CD44. However, XAV939 pretreatment inhibited Tipα-induced EMT and CSC properties in SGC7901 cells or CSCs. These results suggest that Tipα promotes EMT and CSC-like properties in gastric cancer cells through activation of Wnt/β-catenin signaling pathway, thereby accelerating the progression of gastric cancer.

The TNF-Alpha Inducing Protein is Associated With Gastric Inflammation and Hyperplasia in a Murine Model of Helicobacter pylori Infection

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that colonizes the human stomach leading to the development of chronic gastritis, peptic ulcers and gastric adenocarcinoma. A combination of host, environment and bacterial virulence factors contribute to disease development. The H. pylori TNFα inducing protein (Tipɑ) is a virulence factor shown to induce multiple pro-inflammatory cytokines in addition to TNFα in vitro. The goal of the present study was to elucidate the role of Tipα in promoting inflammation in vivo and to identify the molecular pathways associated with Tipα associated virulence. Mice were infected with wild-type Sydney strain (SS1) or a tipα mutant (Δtipα) for 1 month and 4 months. We also completed a second 4 months infection including a 1:1 SS1 to Δtipα co-infected group in addition to SS1 and Δtipα infected groups. The expression of TNFα, and KC were significantly higher in the SS1 infected group compared to both uninfected control (naïve) and Δtipα groups. Mice infected with Tipα expressing SS1 induced more severe histological gastritis and developed hyperplasia compared to Δtipα infected mice. Microarray analysis of gastric epithelial cells co-cultured with recombinant Tipα (rTipα) demonstrates up-regulation of the NFκB pathway. This data suggest Tipα plays an important role in H. pylori induced inflammation.

Nanomechanical Hallmarks of Helicobacter pylori Infection in Pediatric Patients

Background: the molecular mechanism of gastric cancer development related to Helicobacter pylori (H. pylori) infection has not been fully understood, and further studies are still needed. Information regarding nanomechanical aspects of pathophysiological events that occur during H. pylori infection can be crucial in the development of new prevention, treatment, and diagnostic measures against clinical consequences associated with H. pylori infection, including gastric ulcer, duodenal ulcer, and gastric cancer. Methods: in this study, we assessed mechanical properties of children’s healthy and H. pylori positive stomach tissues and the mechanical response of human gastric cells exposed to heat-treated H. pylori cells using atomic force microscopy (AFM NanoWizard 4 BioScience JPK Instruments Bruker). Elastic modulus (i.e., the Young’s modulus) was derived from the Hertz–Sneddon model applied to force-indentation curves. Human tissue samples were evaluated using rapid urease tests to identify H. pylori positive samples, and the presence of H. pylori cells in those samples was confirmed using immunohistopathological staining. Results and conclusion: collected data suggest that nanomechanical properties of infected tissue might be considered as markers indicated H. pylori presence since infected tissues are softer than uninfected ones. At the cellular level, this mechanical response is at least partially mediated by cell cytoskeleton remodeling indicating that gastric cells are able to tune their mechanical properties when subjected to the presence of H. pylori products. Persistent fluctuations of tissue mechanical properties in response to H. pylori infection might, in the long-term, promote induction of cancer development.

Role of TNF-α-Inducing Protein Secreted by Helicobacter pylori as a Tumor Promoter in Gastric Cancer and Emerging Preventive Strategies

The tumor necrosis factor-α (TNF-α)-inducing protein (tipα) gene family, comprising Helicobacter pylori membrane protein 1 (hp-mp1) and tipα, has been identified as a tumor promoter, contributing to H. pylori carcinogenicity. Tipα is a unique H. pylori protein with no similarity to other pathogenicity factors, CagA, VacA, and urease. American H. pylori strains cause human gastric cancer, whereas African strains cause gastritis. The presence of Tipα in American and Euro-Asian strains suggests its involvement in human gastric cancer development. Tipα secreted from H. pylori stimulates gastric cancer development by inducing TNF-α, an endogenous tumor promoter, through its interaction with nucleolin, a Tipα receptor. This review covers the following topics: tumor-promoting activity of the Tipα family members HP-MP1 and Tipα, the mechanism underlying this activity of Tipα via binding to the cell-surface receptor, nucleolin, the crystal structure of rdel-Tipα and N-terminal truncated rTipα, inhibition of Tipα-associated gastric carcinogenesis by tumor suppressor B-cell translocation gene 2 (BTG2/TIS21), and new strategies to prevent and treat gastric cancer. Thus, Tipα contributes to the carcinogenicity of H. pylori by a mechanism that differs from those of CagA and VacA.

Helicobacter pylori induces epithelial-mesenchymal transition in gastric carcinogenesis via the AKT/GSK3β signaling pathway

Helicobacter pylori (H. pylori) is a main risk factor for gastric cancer (GC). Epithelial-mesenchymal transition (EMT) is involved in the development and progression of H. pylori-associated GC. However, the exact molecular mechanism of this process remains unclear. The AKT/GSK3β signaling pathway has been demonstrated to promote EMT in several types of cancer. The present study investigated whether H. pylori infection induced EMT, and promoted the development and metastasis of cancer in the normal gastric mucosa, and whether this process was dependent on AKT activation. The expression levels of the EMT-associated proteins, including E-cadherin and N-cadherin, were determined in 165 gastric mucosal samples of different disease stages by immunohistochemical analysis. The expression levels of E-cadherin, N-cadherin, AKT, phosphorylated (p-)AKT (Ser473), GSK3β and p-GSK3β (Ser9) were further determined in H. pylori-infected Mongolian gerbil gastric tissues and cells co-cultured with H. pylori by immunohistochemical analysis and western blotting. The results indicated that the expression levels of the epithelial marker E-cadherin were decreased, whereas the expression levels of the mesenchymal marker N-cadherin were increased during gastric carcinogenesis. Their expression levels were associated with H. pylori infection. Furthermore, H. pylori infection resulted in downregulation of E-cadherin expression and upregulation of N-cadherin expression in Mongolian gerbils and GES-1 cells. In addition, an investigation of the associated mechanism of action revealed that p-AKT (Ser473) and p-GSK3β (Ser9) were activated in GES-1 cells following co-culture with H. pylori. Furthermore, following pretreatment of the cells with the AKT inhibitor VIII, the expression levels of E-cadherin, N-cadherin, p-AKT and p-GSK3β did not show significant differences between GES-1 cells that were co-cultured with or without H. pylori. The levels of p-AKT and p-GSK3β were increased in H. pylori-infected Mongolian gerbils. In conclusion, the present study demonstrated that H. pylori infection activated AKT and resulted in the phosphorylation and inactivation of GSK3β, which in turn promoted early stage EMT. These effects were AKT-dependent. This mechanism may serve as a prerequisite for GC development.

Sub-Toxic Concentrations of Ionic Liquids Enhance Cell Migration by Reducing the Elasticity of the Cellular Lipid Membrane

Cell migration is a universal and crucial mechanism for life. It is required in a series of physiological processes, in wound repair and immune response and is involved in several pathological conditions, including cancer and virus dissemination. Among the several biochemical and biophysical routes, changing cell membrane elasticity holds the promise to be a universal strategy to alter cell mobility. Due to their affinity with cell membranes, ionic liquids (ILs) may play an important role. This work focuses on the effect of subtoxic amounts of imidazolium-ILs on the migration of the model cancer cell line MDA-MB-231. Here we show that ILs are able to enhance cell mobility by reducing the elasticity of the cellular lipid membrane, and that both mobility and elasticity can be tuned by IL-concentration and IL-cation chain length. This biochemical-physical mechanism is potentially valid for all mammalian cells, and its impact in bionanomedicine and bionanotechnology is discussed.

Mechanisms of the Epithelial-Mesenchymal Transition and Tumor Microenvironment in Helicobacter pylori-Induced Gastric Cancer

Helicobacter pylori (H. pylori) is one of the most common human pathogens, affecting half of the world’s population. Approximately 20% of the infected patients develop gastric ulcers or neoplastic changes in the gastric stroma. An infection also leads to the progression of epithelial–mesenchymal transition within gastric tissue, increasing the probability of gastric cancer development. This paper aims to review the role of H. pylori and its virulence factors in epithelial–mesenchymal transition associated with malignant transformation within the gastric stroma. The reviewed factors included: CagA (cytotoxin-associated gene A) along with induction of cancer stem-cell properties and interaction with YAP (Yes-associated protein pathway), tumor necrosis factor α-inducing protein, Lpp20 lipoprotein, Afadin protein, penicillin-binding protein 1A, microRNA-29a-3p, programmed cell death protein 4, lysosomal-associated protein transmembrane 4β, cancer-associated fibroblasts, heparin-binding epidermal growth factor (HB-EGF), matrix metalloproteinase-7 (MMP-7), and cancer stem cells (CSCs). The review summarizes the most recent findings, providing insight into potential molecular targets and new treatment strategies for gastric cancer.

Nucleolin-Sle A Glycoforms as E-Selectin Ligands and Potentially Targetable Biomarkers at the Cell Surface of Gastric Cancer Cells

BACKGROUND

Gastric cancer (GC) is a major health burden worldwide, with half of patients developing metastases within 5 years after treatment, urging novel biomarkers for diagnosis and efficient therapeutic targeting. Sialyl-Lewis A (SLeA), a terminal glycoepitope of glycoproteins and glycolipids, offers tremendous potential towards this objective. It is rarely expressed in healthy tissues and blood cells, while it is present in highly metastatic cell lines and metastases. SLeA is also involved in E-selectin mediated metastasis, making it an ideal target to control disease dissemination.

METHODS AND RESULTS

To improve cancer specificity, we have explored the SLeA-glycoproteome of six GC cell models, with emphasis on glycoproteins showing affinity for E-selectin. A novel bioinformatics-assisted algorithm identified nucleolin (NCL), a nuclear protein, as a potential targetable biomarker potentially involved in metastasis. Several immunoassays, including Western blot and in situ proximity ligation reinforced the existence of cell surface NCL-SLeA glycoforms in GC. The NCL-SLeA glycophenotype was associated with decreased survival and was not reflected in relevant healthy tissues.

CONCLUSIONS

NCL-SLeA is a biomarker of poor prognosis in GC holding potential for precise cancer targeting. This is the first report describing SLeA in preferentially nuclear protein, setting a new paradigm for cancer biomarkers discovery and targeted therapies.

Importance of TNF-alpha and its alterations in the development of cancers

TNF-alpha is involved in many physiologic and pathologic cellular pathways, including cellular proliferation, differentiation, and death, regulation of immunologic reactions to different cells and molecules, local and vascular invasion of neoplasms, and destruction of tumor vasculature. It is obvious that because of integrated functions of TNF-alpha inside different physiologic systems, it cannot be used as a single-agent therapy for neoplasms; however, long-term investigation of its different cellular pathways has led to recognition of a variety of subsequent molecules with more specific interactions, and therefore, might be suitable as prognostic and therapeutic factors for neoplasms. Here, we will review different aspects of the TNF-alpha as a cytokine involved in both physiologic functions of cells and pathologic abnormalities, most importantly, cancers.

Hepatoma-derived growth factor participates in Helicobacter Pylori-induced neutrophils recruitment, gastritis and gastric carcinogenesis

Helicobacter pylori (Hp) infection and overexpression of hepatoma-derived growth factor (HDGF) are involved in gastric carcinogenesis. However, the relationship between Hp-induced gastric diseases and HDGF upregulation is not yet completely clear. This study aimed to elucidate the role of HDGF in Hp-induced gastric inflammation and carcinogenesis. HDGF expression in gastric biopsy and serum from patients was analyzed by immunohistochemical and ELISA analysis, respectively. Hp and gastric cells coculture system was employed to delineate the mechanism underlying HDGF overexpression during Hp infection. The gastric pathologies of wild type and HDGF knockout mice after Hp infection were investigated by immunohistochemical, immunoblot, and immunofluorescence analyses. HDGF level was significantly elevated in patients with Hp infection or intestinal metaplasia (IM, a precancerous lesion), and HDGF overexpression was positively correlated with Hp load, IM, and neutrophil infiltration in gastric biopsy. Consistently, patients with Hp infection or IM had significantly higher serum HDGF level. By using coculture assay, Hp infection led to HDGF upregulation and secretion in gastric cells. In mice model, HDGF ablation significantly suppressed the Hp-induced neutrophil infiltration and inflammatory TNF-α/COX-2 signaling, thereby relieving the tissue damage in stomach. This was further supported by that recombinant HDGF (rHDGF) stimulated the differentiation/chemotaxis of cultured neutrophils and oncogenic behaviors of gastric cells. Time series studies showed that Hp infection elicited an inflammatory TNF-α/HDGF/COX-2 cascade in stomach. HDGF secretion by Hp infection promotes the neutrophils infiltration and relays Hp-induced inflammatory signaling. Thus, HDGF may constitute a novel diagnostic marker and therapeutic target for Hp-induced gastritis and carcinogenesis.

The concept of the okadaic acid class of tumor promoters is revived in endogenous protein inhibitors of protein phosphatase 2A, SET and CIP2A, in human cancers

PURPOSE

The okadaic acid class of tumor promoters, which are inhibitors of protein phosphatases 1 and 2A (PP1 and PP2A), induced tumor promotion in mouse skin, rat glandular stomach, and rat liver. Endogenous protein inhibitors of PP2A, SET and CIP2A, were up-regulated in various human cancers, so it is vital to review the essential mechanisms of tumor promotion by the okadaic acid class compounds, together with cancer progression by SET and CIP2A in humans.

RESULTS AND DISCUSSION

The first part of this review introduces the okadaic acid class compounds and the mechanism of tumor promotion: (1) inhibition of PP1 and PP2A activities of the okadaic acid class compounds; (2) some topics of tumor promotion; (3) TNF-α gene expression as a central mediator in tumor promotion; (4) exposure to the okadaic acid class of tumor promoters in relation to human cancer. The second part emphasizes the overexpression of SET and CIP2A in cancer progression, and the anticancer activity of SET antagonists as follows: (5) isolation and characterization of SET; (6) isolation and characterization of CIP2A; (7) progression of leukemia with SET; (8) progression of breast cancer with SET and CIP2A; (9) progression of lung cancer with SET; (10) anti-carcinogenic effects of SET antagonists OP449 and FTY720; and also (11) TNF-α-inducing protein of Helicobacter pylori, which is a clinical example of the okadaic acid pathway.

CONCLUSIONS

The overexpression of endogenous protein inhibitors of PP2A, SET and CIP2A, is tightly linked to the progression of various human cancers, as well as Alzheimer's disease.

Atomic force microscopy correlates antimetastatic potentials of HepG2 cell line with its redox/energy status: effects of curcumin and Khaya senegalensis

OBJECTIVE

The fatality of cancer is mostly dependent on the possibility of occurrence of metastasis. Thus, if the development of metastasis can be prevented through novel therapeutic strategies targeted against this process, then the success of cancer treatment will drastically increase. In this study, therefore, we evaluated the antimetastatic potentials of an extract of Khaya senegalensis and curcumin on the metastatic liver cell line HepG2, and also assessed the anticancer property of the extract.

METHODS

Cells were cultured and treated with graded concentrations of test substances for 24, 48, or 72 h with provisions made for negative controls. Treated cells were assessed as follows: nanotechnologically - atomic force microscopy (AFM) was used to determine cell stiffness; biochemically - cell cytotoxicity, glutathione level and adenosine triphosphate status, caspase activation and mitochondrial toxicity were considered; and microbiologically - a carrot disk assay was used to assess the anticancer property of the extract of K. senegalensis.

RESULTS

Curcumin and K. senegalensis increased the cell stiffness by 2.6- and 4.0-fold respectively, indicating their antimetastatic effects. Corresponding changes in redox (glutathione level) and energy (adenosine triphosphate) status of the cells were also demonstrated. Further mechanistic studies indicated that curcumin was not mitotoxic in HepG2 cells unlike the K. senegalensis extract. In addition, the extract potently inhibited the Agrobacterium tumefaciens-induced genetic transformation based on carrot disk assay.

CONCLUSION

Cell elasticity measurement data, using AFM, strongly suggested, for the first time, that both curcumin and the extract of K. senegalensis exhibited antimetastatic properties on HepG2 cells.

Meeting the needs of breast cancer: A nucleolin's perspective

A major challenge in the management of breast cancer disease has been the development of metastases. Finding new molecular targets and the design of targeted therapeutic approaches to improve the overall survival and quality of life of these patients is, therefore, of great importance. Nucleolin, which is overexpressed in cancer cells and tumor-associated blood vessels, have been implicated in various processes supporting tumorigenesis and angiogenesis. Additionally, its overexpression has been demonstrated in a variety of human neoplasias as an unfavorable prognostic factor, associated with a high risk of relapse and low overall survival. Hence, nucleolin has emerged as a relevant target for therapeutic intervention in cancer malignancy, including breast cancer. This review focus on the contribution of nucleolin for cancer disease and on the development of therapeutic strategies targeting this protein. In this respect, it also provides a critical analysis about the potential and pitfalls of nanomedicine for cancer therapy.

Low expression of Rap1GAP is associated with epithelial-mesenchymal transition (EMT) and poor prognosis in gastric cancer

Rap1GAP is a crucial tumor suppressor, but its role in gastric cancer (GC) is little investigated. In this study, we found that the expression of Rap1GAP was decreased in GC. Low expression of Rap1GAP was positively correlated with advanced pTNM stage, Borrmann types, tumor diameter and poor prognosis in patients with GC. Low expression of Rap1GAP correlated with loss of E-cadherin expression, and anomalous positivity of MMP2 expression. Multivariate analysis showed that low expression of Rap1GAP was an independent prognostic factor. Ectopic expression of Rap1GAP impaired cell migration and invasion, promoted the expression of E-cadherin and decreased the expression of MMP2. These results suggest that Rap1GAP functions as a novel suppressor of EMT and tumor metastasis in GC, and loss of Rap1GAP predicts poor prognosis in GC.

Changes of serum and peritoneal inflammatory mediators in laparoscopic radical resection for right colon carcinoma

Objective:

The objective of this study is to investigate the effects of laparoscopic and open operation on serum and peritoneal inflammatory mediators in patients with right colon carcinoma.

Patients and Methods:

A total of 100 patients were randomly divided into laparoscopic group (n = 50) and open group (n = 50). The age, sex, operation time, operation blood loss, post-operative Dukes stage, time to first passage of flatus and post-operative hospital stay were recorded. The levels of hypersensitive C reactive protein (hsCRP) and tumour necrosis factor-α (TNF-α) in serum and abdominal exudate were measured by ELISA at the time of pre-operative 2 h and post-operative 6 h and 24 h.

Results:

There was no significant difference in age, sex, Dukes stage and pre-operative inflammatory mediators between the two groups (P > 0.05). The operation time, intraoperative blood loss, time to first passage of flatus and post-operative hospital stay were significantly better in laparoscopic group than those in open operation group. At 6 h and 24 h after operation, the levels of hsCRP and TNF-α in serum and abdominal exudate in laparoscopic group were significantly lower than those in open operation group.

Conclusions:

Laparoscopic surgery for the treatment of right colon carcinoma has the advantages of fewer traumas, less systemic and local inflammatory response, rapider post-operative recovery and shorter hospital stay. It is worthy of clinical application.

Inhibition of TNFα-interacting protein α (Tipα)-associated gastric carcinogenesis by BTG2/TIS21 via downregulating cytoplasmic nucleolin expression

To understand the regulation of Helicobacter pylori (H. pylori)-associated gastric carcinogenesis, we examined the effect of B-cell translocation gene 2 (BTG2) expression on the biological activity of Tipα, an oncoprotein secreted from H. pylori. BTG2, the human ortholog of mouse TIS21 (BTG2/TIS21), has been reported to be a primary response gene that is transiently expressed in response to various stimulations. Here, we report that BTG2 is constitutively expressed in the mucous epithelium and parietal cells of the gastric gland in the stomach. Expression was increased in the mucous epithelium following H. pylori infection in contrast to its loss in human gastric adenocarcinoma. Indeed, adenoviral transduction of BTG2/TIS21 significantly inhibited Tipα activity in MKN-1 and MGT-40, human and mouse gastric cancer cells, respectively, thereby downregulating tumor necrosis factor-α (TNFα) expression and Erk1/2 phosphorylation by reducing expression of nucleolin, a Tipα receptor. Chromatin immunoprecipitation proved that BTG2/TIS21 inhibited Sp1 expression and its binding to the promoter of the nucleolin gene. In addition, BTG2/TIS21 expression significantly reduced membrane-localized nucleolin expression in cancer cells, and the loss of BTG2/TIS21 expression induced cytoplasmic nucleolin availability in gastric cancer tissues, as evidenced by immunoblotting and immunohistochemistry. Higher expression of BTG2 and lower expression of nucleolin were accompanied with better overall survival of poorly differentiated gastric cancer patients. This is the first report showing that BTG2/TIS21 inhibits nucleolin expression via Sp1 binding, which might be associated with the inhibition of H. pylori-induced carcinogenesis. We suggest that BTG2/TIS21 is a potential inhibitor of nucleolin in the cytoplasm, leading to inhibition of carcinogenesis after H. pylori infection.

Cell softening in malignant progression of human lung cancer cells by activation of receptor tyrosine kinase AXL

To study the role of cell softening in malignant progression, Transwell assay and atomic force microscope were used to classify six human non-small cell lung cancer cell lines into two groups: a high motility-low stiffness (HMLS) group and a low motility-high stiffness (LMHS) group. We found a significant role of activity of the AXL receptor tyrosine kinase, which belongs to the TAM (Tyro3, AXL, Mer) family, in the stimulation of motility and cell softening. HMLS cells expressed higher AXL levels than LMHS cells and contained phosphorylated AXL. H1703 LMHS cells transfected with exogenous AXL exhibited increased motility and decreased stiffness, with low levels of actin stress fibre formation. Conversely, the AXL-specific inhibitor R428 and AXL-targeting siRNA reduced motility and increased stiffness in H1299 HMLS cells. Knockdown of AXL stimulated actin stress fibre formation, which inhibited tumour formation in a mouse xenograft model. The Ras/Rac inhibitor SCH 51344, which blocks disruption of actin stress fibres, exerted similar effects to AXL inactivation. We therefore propose that the Ras/Rac pathway operates downstream of AXL. Thus, AXL activation-induced cell softening promotes malignant progression in non-small cell lung cancer and represents a key biophysical property of cancer cells.

ITGBL1 Predicts a Poor Prognosis and Correlates EMT Phenotype in Gastric Cancer

Integrin, beta-like 1 (ITGBL1), a β-integrin-related extracellular matrix protein, was found more commonly up-regulated in gastric cancer (GC) by screening and analyzing Gene Expression Omnibus (GEO) and Oncomine databases, reminding us to explore its prognostic significance in GC. In our current study, we observed that ITGBL1 expression was significantly up-regulated in GC compared with normal controls in clinical specimens. In addition, elevated ITGBL1 expression was positively correlated with patients' tumor-node-metastasis (TNM) stage and distant metastasis. Kaplan-Meier analysis indicated that high ITGBL1 expression was significantly associated with shorter survival times in GC patients. Multivariate Cox regression analysis confirmed ITGBL1 expression as an independent prognostic factor in GC. Gene set enrichment analysis (GSEA) of multiple GEO datasets revealed a close relationship between ITGBL1 expression and the KRAS/epithelial-mesenchymal transition (EMT) signaling pathway. In conclusion, these data provide evidences that ITGBL1 is a potential predictor and may be involved in cancer cell invasion and metastasis via inducing EMT, and the ITGBL1-related pathways may represent a novel therapeutic strategy for treatment of GC.

Multifaceted Nucleolin Protein and Its Molecular Partners in Oncogenesis

Discovered in 1973, nucleolin is one of the most abundant phosphoproteins of the nucleolus. The ability of nucleolin to be involved in many cellular processes is probably related to its structural organization and its capability to form many different interactions with other proteins. Many functions of nucleolin affect cellular processes involved in oncogenesis-for instance: in ribosome biogenesis; in DNA repair, remodeling, and genome stability; in cell division and cell survival; in chemokine and growth factor signaling pathways; in angiogenesis and lymphangiogenesis; in epithelial-mesenchymal transition; and in stemness. In this review, we will describe the different functions of nucleolin in oncogenesis through its interaction with other proteins.

Helicobacter pylori antigenic Lpp20 is a structural homologue of Tipα and promotes epithelial-mesenchymal transition

BACKGROUND

Helicobacter pylori is a bacterium that affects about 50% of the world population and, despite being often asymptomatic, it is responsible of several gastric diseases, from gastritis to gastric cancer. The protein Lpp20 (HP1456) plays an important role in bacterium survival and host colonization, but the possibility that it might be involved in the etiology of H. pylori-related disorders is an unexplored issue. Lpp20 is a lipoprotein bound to the external membrane of the bacterium, but it is also secreted inside vesicles along with other two proteins of the same operon, i.e. HP1454 and HP1457.

RESULTS

In this study we determined the crystal structure of Lpp20 and we found that it has a fold similar to a carcinogenic factor released by H. pylori, namely Tipα. We demonstrate that Lpp20 promotes cell migration and E-cadherin down-regulation in gastric cancer cells, two events recalling the epithelial-mesenchymal transition (EMT) process. Differently from Tipα, Lpp20 also stimulates cell proliferation.

CONCLUSIONS

This identifies Lpp20 as a new pathogenic factor produced by H. pylori that promotes EMT and thereby the progression of cancer to the metastatic state.

Integrated analysis of mRNA and miRNA expression in HeLa cells expressing low levels of Nucleolin

Nucleolin is an essential protein that plays important roles in the regulation of cell cycle and cell proliferation. Its expression is up regulated in many cancer cells but its molecular functions are not well characterized. Nucleolin is present in the nucleus where it regulates gene expression at the transcriptional and post-transcriptional levels. Using HeLa cells depleted in nucleolin we performed an mRNA and miRNA transcriptomics analysis to identify biological pathways involving nucleolin. Bioinformatic analysis strongly points to a role of nucleolin in lipid metabolism, and in many signaling pathways. Down regulation of nucleolin is associated with lower level of cholesterol while the amount of fatty acids is increased. This could be explained by the decreased and mis-localized expression of the transcription factor SREBP1 and the down-regulation of enzymes involved in the beta-oxidation and degradation of fatty acids. Functional classification of the miRNA-mRNA target genes revealed that deregulated miRNAs target genes involved in apoptosis, proliferation and signaling pathways. Several of these deregulated miRNAs have been shown to control lipid metabolism. This integrated transcriptomic analysis uncovers new unexpected roles for nucleolin in metabolic regulation and signaling pathways paving the way to better understand the global function of nucleolin within the cell.

The cellular character of liquefaction degeneration in oral lichen planus and the role of interferon gamma

BACKGROUND

Oral lichen planus (OLP) is a T-cell-mediated chronic inflammatory oral mucosal disease of unknown etiology, and liquefaction degeneration in the basal keratinocytes is one of the specific histological changes. However, the understanding of liquefaction degeneration is still very limited, and how does it affect the prognosis of LP is largely unknown. Therefore, the objective of this study was to clarify the intrinsic change behind the liquefaction degeneration in lichen planus and to evaluate the effect of the OLP-typical cytokine, IFN-γ, on these changes.

MATERIALS AND METHODS

Biopsies were collected from patients with OLP; immunochemistry staining was performed to analyze E-cadherin, vimentin, CK19, β1 integrin, nestin, STAT1, and STAT3 expression. Primary oral epithelial cells were cultured in vitro, and 20 ng/mL IFN-γ was applied to assay the effect on epithelial cells.

RESULTS

E-cadherin expression was decreased but vimentin expression was increased in the OLP epithelial cells that undergo liquefaction degeneration, showing the typical epithelial-mesenchymal transition (EMT) alteration. In vitro research showed that the OLP-typical cytokine, IFN-γ, possesses EMT-inducing ability, and the primary oral epithelial cells stimulated by IFN-γ acquired some properties of cancer stem cells, expressing more β1 integrin, α6 integrin, and nestin. In addition, the major downstream mediator of IFN-γ receptor, STAT1, was expressed more intensive and extensive with the malignant transition of OLP.

CONCLUSION

Liquefaction degeneration in oral lichen planus is an EMT phenomenon, the IFN-γ may be the main inducer, and IFN-γ signaling might be implicated in malignant transition of OLP.

Down-regulation of histone deacetylase 4, -5 and -6 as a mechanism of synergistic enhancement of apoptosis in human lung cancer cells treated with the combination of a synthetic retinoid, Am80 and green tea catechin

(-)-Epigallocatechin gallate (EGCG), a green tea catechin, acts as a synergist with various anticancer drugs, including retinoids. Am80 is a synthetic retinoid with a different structure from all-trans-retinoic acid: Am80 is now clinically utilized as a new drug for relapsed and intractable acute promyelocytic leukemia patients. Our experiments showed that the combination of EGCG and Am80 synergistically induced both apoptosis in human lung cancer cell line PC-9 and up-regulated expressions of growth arrest and DNA damage-inducible gene 153 (GADD153), death receptor 5, and p21^waf1 genes in the cells. To understand the mechanisms of synergistic anticancer activity of the combination, we gave special attention to the lysine acetylation of proteins. Proteomic analysis using nanoLC-ESI-MS/MS revealed that PC-9 cells treated with the combination contained 331 acetylated proteins, while nontreated cells contained 553 acetylated proteins, and 59 acetylated proteins were found in both groups. Among them, the combination increased acetylated-p53 and acetylated-α-tubulin through reduction of histone deacetylase (HDAC) activity in cytosol fraction, although the levels of acetylation in histones H3 or H4 did not change, and the combination reduced protein levels of HDAC4, -5 and -6 by 20% to 80%. Moreover, we found that a specific inhibitor of HDAC4 and -5 strongly induced p21^waf1 gene expression, and that of HDAC6 induced both GADD153 and p21^waf1 gene expression, which resulted in apoptosis. All results demonstrate that EGCG in combination with Am80 changes levels of acetylation in nonhistone proteins via down-regulation of HDAC4, -5 and -6 and stimulates apoptotic induction.

Roles of nucleolin. Focus on cancer and anti-cancer therapy

Nucleolin, a multifunctional protein distributed in the nucleolus, participates in many modulations including rDNA transcription, RNA metabolism, and ribosome assembly. Nucleolin is also found in the cytoplasm and on the cell membrane, and surface nucleolin can bind to various ligands to affect many physiological functions. The expression and localization of nucleolin is often abnormal in cancers, as the differential distribution of nucleolin in cancer can influence the carcinogenesis, proliferation, survival, and metastasis of cancer cells, leading to the cancer progression. Thus, nucleolin may be a novel and promising target for anti-cancer treatment. Here, we describe how nucleolin act functions in cancer development and describe nucleolin-dependent anti-cancer therapies.

Biophysical Approach to Mechanisms of Cancer Prevention and Treatment with Green Tea Catechins

Green tea catechin and green tea extract are now recognized as non-toxic cancer preventives for humans. We first review our brief historical development of green tea cancer prevention. Based on exciting evidence that green tea catechin, (−)-epigallocatechin gallate (EGCG) in drinking water inhibited lung metastasis of B16 melanoma cells, we and other researchers have studied the inhibitory mechanisms of metastasis with green tea catechins using biomechanical tools, atomic force microscopy (AFM) and microfluidic optical stretcher. Specifically, determination of biophysical properties of cancer cells, low cell stiffness, and high deformability in relation to migration, along with biophysical effects, were studied by treatment with green tea catechins. The study with AFM revealed that low average values of Young’s moduli, indicating low cell stiffness, are closely associated with strong potential of cell migration and metastasis for various cancer cells. It is important to note that treatments with EGCG and green tea extract elevated the average values of Young’s moduli resulting in increased stiffness (large elasticity) of melanomas and various cancer cells. We discuss here the biophysical basis of multifunctions of green tea catechins and green tea extract leading to beneficial effects for cancer prevention and treatment.

Quantum dot-based molecular imaging of cancer cell growth using a clone formation assay

This aim of the present study was to investigate clonal growth behavior and analyze the proliferation characteristics of cancer cells. The MCF‑7 human breast cancer cell line, SW480 human colon cancer cell line and SGC7901 human gastric cancer cell line were selected to investigate the morphology of cell clones. Quantum dot‑based molecular targeted imaging techniques (which stained pan‑cytokeratin in the cytoplasm green and Ki67 in the cell nucleus yellow or red) were used to investigate the clone formation rate, cell morphology, discrete tendency, and Ki67 expression and distribution in clones. From the cell clone formation assay, the MCF‑7, SW480 and SGC7901 cells were observed to form clones on days 6, 8 and 12 of cell culture, respectively. These three types of cells had heterogeneous morphology, large nuclear:cytoplasmic ratios, and conspicuous pathological mitotic features. The cells at the clone periphery formed multiple pseudopodium. In certain clones, cancer cells at the borderline were separated from the central cell clusters or presented a discrete tendency. With quantum dot‑based molecular targeted imaging techniques, cells with strong Ki67 expression were predominantly shown to be distributed at the clone periphery, or concentrated on one side of the clones. In conclusion, cancer cell clones showed asymmetric growth behavior, and Ki67 was widely expressed in clones of these three cell lines, with strong expression around the clones, or aggregated at one side. Cell clone formation assay based on quantum dots molecular imaging offered a novel method to study the proliferative features of cancer cells, thus providing a further insight into tumor biology.

Inflammatory microenvironment contributes to epithelial-mesenchymal transition in gastric cancer

Gastric cancer (GC) is the fifth most common malignancy in the world. The major cause of GC is chronic infection with Helicobacter pylori (H. pylori). Infection with H. pylori leads to an active inflammatory microenvironment that is maintained by immune cells such as T cells, macrophages, natural killer cells, among other cells. Immune cell dysfunction allows the initiation and accumulation of mutations in GC cells, inducing aberrant proliferation and protection from apoptosis. Meanwhile, immune cells can secrete certain signals, including cytokines, and chemokines, to alter intracellular signaling pathways in GC cells. Thus, GC cells obtain the ability to metastasize to lymph nodes by undergoing the epithelial-mesenchymal transition (EMT), whereby epithelial cells lose their epithelial attributes and acquire a mesenchymal cell phenotype. Metastasis is a leading cause of death for GC patients, and the involved mechanisms are still under investigation. In this review, we summarize the current research on how the inflammatory environment affects GC initiation and metastasis via EMT.

Cell stiffness determined by atomic force microscopy and its correlation with cell motility

BACKGROUND

Cell stiffness is a crucial mechanical property that is closely related to cell motility. AFM is the most prevalent method used to determine cell stiffness by the quantitative parameter designated as Young's modulus. Young's modulus is regarded as a biomarker of cell motility, especially in estimating the metastasis of cancer cells, because in recent years, it has been repeatedly shown that cancerous cells are softer than their benign counterparts. However, some conflicting evidence has shown that cells with higher motility are sometimes stiffer than their counterparts. Thus, the correlation between cell stiffness and motility remains a matter of debate.

SCOPE OF REVIEW

In this review, we first summarize the reports on correlations between cell motility and stiffness determined by AFM and then discuss the major determinants of AFM-determined cell stiffness with a focus on the cytoskeleton, nuclear stiffness and methodological issues. Last, we propose a possible correlation between cell stiffness and motility and the possible explanations for the conflicting evidence.

MAJOR CONCLUSIONS

The AFM-determined Young's modulus is greatly affected by the characteristics of the cytoskeleton, as well as the procedures and parameters used in detection. Young's modulus is a reliable biomarker for the characterization of metastasis; however, reliability is questioned in the evaluation of pharmacologically or genetically modified motility.

GENERAL SIGNIFICANCE

This review provides an overview of the current understanding of the correlation between AFM-determined cell stiffness and motility, the determinants of this detecting method, as well as clues to optimize detecting parameters.

A multi-targeted approach to suppress tumor-promoting inflammation

Cancers harbor significant genetic heterogeneity and patterns of relapse following many therapies are due to evolved resistance to treatment. While efforts have been made to combine targeted therapies, significant levels of toxicity have stymied efforts to effectively treat cancer with multi-drug combinations using currently approved therapeutics. We discuss the relationship between tumor-promoting inflammation and cancer as part of a larger effort to develop a broad-spectrum therapeutic approach aimed at a wide range of targets to address this heterogeneity. Specifically, macrophage migration inhibitory factor, cyclooxygenase-2, transcription factor nuclear factor-κB, tumor necrosis factor alpha, inducible nitric oxide synthase, protein kinase B, and CXC chemokines are reviewed as important antiinflammatory targets while curcumin, resveratrol, epigallocatechin gallate, genistein, lycopene, and anthocyanins are reviewed as low-cost, low toxicity means by which these targets might all be reached simultaneously. Future translational work will need to assess the resulting synergies of rationally designed antiinflammatory mixtures (employing low-toxicity constituents), and then combine this with similar approaches targeting the most important pathways across the range of cancer hallmark phenotypes.

Associations of Il-1 Family-Related Polymorphisms With Gastric Cancer Risk and the Role of Mir-197 In Il-1f5 Expression

To explore whether the roles of IL-1 family single nucleotide polymorphisms (SNPs) of the microRNA binding sites (miR-SNPs) in the 3' untranslated region (3'-UTR) of their target genes in the progression of gastric cancer (GC) and verify the relationship between miR-197 with chronic inflammatory gene-IL1-F5 by microRNA target prediction, a case-control study which consisted of 500 cases and 500 frequency-matched healthy controls was conducted. Single nucleotide polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) or allele-specific PCR (AS-PCR). Association between SNPs and GC risk was evaluated by adjusted odds ratios (ORs) and 95% confidence intervals (CIs) in unconditional logistic regression analyses. Quantitative real-time (qRT) PCR assay and Western Blot analyses were performed to analyze the miR-197 expression and the IL1-F5 expression. The variant homozygote and heterozygote genotype of rs9005 in IL-1RN were significantly associated with increased risks of GC (ORadjusted [95%CI]: 1.71[1.04-2.81] and ORadjusted[95%CI]: 1.36 [1.04-1.78]). Compared with the wild heterozygote genotype, the variant heterozygote genotype of rs2472188 and rs2515401 in IL-1F5 polymorphisms were significantly associated with increased GC risks (ORadjusted [95%CI]: 1.51[1.15-1.99] and ORadjusted[95%CI]: 1.36[1.04-1.76]), but no significant differences existed in other 7 IL-1 family SNPs (rs2856836 in IL-1A, rs3732131 in IL-1R1, rs1135354 and rs3771157 in IL-18RA, rs3180235, rs957201 and rs2515402 in IL-1F5) with GC. The recombinant plasmid-pGenesil-1-miR-197 could upregulate the expression of miR-197 and downregulate the expression of IL-1F5 in human gastric cancer cell lines SGC-7901 and BGC-823 cells after transfection, and the miR-197 inhibitor could facilitate the expression of IL1-F5 after transfecting the same cell lines. These results suggested that SNPs in the IL-1 family genes play important roles in the development of GC and the IL-1F5 might be the target gene of miR-197, and miR-197 might negatively regulate its expression.

Nucleolin stabilizes G-quadruplex structures folded by the LTR promoter and silences HIV-1 viral transcription

Folding of the LTR promoter into dynamic G-quadruplex conformations has been shown to suppress its transcriptional activity in HIV-1. Here we sought to identify the proteins that control the folding of this region of proviral genome by inducing/stabilizing G-quadruplex structures. The implementation of electrophorethic mobility shift assay and pull-down experiments coupled with mass spectrometric analysis revealed that the cellular protein nucleolin is able to specifically recognize G-quadruplex structures present in the LTR promoter. Nucleolin recognized with high affinity and specificity the majority, but not all the possible G-quadruplexes folded by this sequence. In addition, it displayed greater binding preference towards DNA than RNA G-quadruplexes, thus indicating two levels of selectivity based on the sequence and nature of the target. The interaction translated into stabilization of the LTR G-quadruplexes and increased promoter silencing activity; in contrast, disruption of nucleolin binding in cells by both siRNAs and a nucleolin binding aptamer greatly increased LTR promoter activity. These data indicate that nucleolin possesses a specific and regulated activity toward the HIV-1 LTR promoter, which is mediated by G-quadruplexes. These observations provide new essential insights into viral transcription and a possible low mutagenic target for antiretroviral therapy.

Pathogenesis of Gastric Cancer

Gastric cancer (GC) is the fifth most common malignancy and the third leading cause of cancer-related death worldwide. GC is a heterogeneous disease and the endpoint of a long multistep process largely influenced by Helicobacter pylori infection, genetic susceptibility, and environmental factors. In a subset of GC cases, infection with the Epstein-Barr virus (EBV) may also be involved. The development of GC is the consequence of the accumulation of multiple epi/genetic changes during the patient's lifetime that will result in oncogenic activation and/or tumor suppressor pathways' inactivation. This review will focus on the most recent updates on the characterization of the molecular phenotypes of sporadic and hereditary GC. This article will also update the most recent findings on the relationship between H. pylori infection and stem cells at the origin of GC. The understanding of the molecular genetics underlying gastric carcinogenesis is of paramount importance to identify novel potential targets for the development of screening and prognostic markers that can be clinically valuable for the management of GC patients and for the design of clinical trials.

NDRG1 attenuates epithelial-mesenchymal transition of nasopharyngeal cancer cells via blocking Smad2 signaling

N-myc downstream-regulated gene 1 (NDRG1) has been implicated in tumorigenesis and metastasis in different cancers. However, its role in nasopharyngeal carcinoma remains unknown. We found that NDRG1 expression level was high in nasopharyngeal cancer 5-8F cells but low in 5-8F-LN cells with lymphatic metastasis potential. Knockdown of NDRG1 by shRNA promoted 5-8F cell proliferation, migration, and invasion in vitro and its tumorigenesis in vivo. Moreover, NDRG1 deficiency induced an epithelial-mesenchymal transition (EMT) of 5-8F cells as shown by an attenuation of E-cadherin and an induction of N-cadherin and vimentin expression. NDRG1 knockdown also enhanced Smad2 expression and phosphorylation. Smad2 signaling was attenuated in 5-8F cells but was significantly activated in 5-8F-LN cells. Knockdown of Smad2 restored E-cadherin but attenuated N-cadherin expression in NDRG1-deficient 5-8F cells, suggesting a reduction of EMT. Consistently, blockade of Smad2 in 5-8F-LN cells increased E-cadherin while diminishing N-cadherin and vimentin expression. These data indicate that Smad2 mediates the NDRG1 deficiency-induced EMT of 5-8F cells. In tumors derived from NDRG1-deficient 5-8F cells, E-cadherin expression was inhibited while vimentin and Smad2 were increased in a large number of cancer cells. Most importantly, NDRG1 expression was attenuated in human nasopharyngeal carcinoma tissues, resulted in a lower survival rate in patients. The NDRG1 was further decreased in the detached nasopharyngeal cancer cells, which was associated with a further reduced survival rate in patients with lymphatic metastasis. Taken together, these results demonstrated that NDRG1 prevents nasopharyngeal tumorigenesis and metastasis via inhibiting Smad2-mediated EMT of nasopharyngeal cells.

Morphological changes in human gastric epithelial cells induced by nuclear targeting of Helicobacter pylori urease subunit A

Nuclear targeting of bacterial proteins and their pathological effects on host cells are an emerging pathogenic mechanism in bacteria. We have previously reported that urease subunit A (UreA) of Helicobacter pylori targets the nuclei of COS-7 cells through nuclear localization signals (NLSs). This study further investigated whether UreA of H. pylori targets the nuclei of gastric epithelial cells and then induces molecular and cellular changes in the host cells. H. pylori 26695 strain produced and secreted outer membrane vesicles (OMVs). UreA was translocated into gastric epithelial AGS cells through outer membrane vesicles (OMVs) and then targeted the nuclei of AGS cells. Nuclear targeting of rUreA did not induce host cell death, but resulted in morphological changes, such as cellular elongation, in AGS cells. In contrast, AGS cells treated with rUreA?NLS proteins did not show this morphological change. Next generation sequencing revealed that nuclear targeting of UreA differentially regulated 102 morphogenesis- related genes, of which 67 and 35 were up-regulated and down-regulated, respectively. Our results suggest that nuclear targeting of H. pylori UreA induces both molecular and cellular changes in gastric epithelial cells.

Antimetastatic effects of Celastrus orbiculatus on human gastric adenocarcinoma by inhibiting epithelial-mesenchymal transition and NF-κB/snail signaling pathway

AIM OF THE STUDY

Celastrus orbiculatus has been used as a folk medicine in China for the treatment of many diseases. In the laboratory, the ethyl acetate extract of Celastrus orbiculatus (COE) displays a wide range of anticancer functions. However, the inhibition of the metastasis mechanism of COE in gastric cancer cells has not been investigated so far. The present study was undertaken to determine if the antimetastatic effects of COE were involved in inhibition of the epithelial-mesenchymal transition (EMT) of human gastric adenocarcinoma SGC-7901 cells.

METHODS

The adhesion, invasion, and migration of SGC-7901 cells were determined by COE treatment in vitro, using Matrigel-coated plate, transwell membrane chamber, and wound healing models, respectively. In vivo, the growth-inhibiting and antimetastatic effects of COE on the nude mice model of gastric cancer were tested and the mechanisms were explored. The expression of EMT markers and nuclear factor κB (NF-κB)/Snail signaling pathway were evaluated by using western blotting and immunohistochemistry.

RESULTS

Treatment with COE dose-dependently inhibited the proliferation, adhesion, invasion, and migration of SGC-7901 cells in vitro, which was realized by enhancing the expression of E-cadherin and reducing N-cadherin and vimentin expression. Moreover, COE suppressed the activation of NF-κB/Snail signaling pathway induced by tumor necrosis factor-α. In addition, COE effectively suppressed tumor growth and metastasis in the nude mice model due to reduced expression of N-cadherin, vimentin, NF-κB p65, and Snail and increased expression of E-cadherin in the tumor tissues.

CONCLUSION

Our findings provided new evidence that COE is an effective inhibitor of metastatic potential of SGC-7901 cells through suppression of EMT and NF-κB/Snail signal pathway. Based on these findings, COE may be considered a novel anticancer agent for the treatment of metastasis in gastric cancer.

Social defeat stress promotes tumor growth and angiogenesis by upregulating vascular endothelial growth factor/extracellular signal-regulated kinase/matrix metalloproteinase signaling in a mouse model of lung carcinoma

Numerous epidemiological and experimental animal studies have indicated that chronic psychological stress may promote tumor development. However, the underlying molecular mechanisms by which chronic stress promotes tumorigenesis remain to be fully elucidated and animal models have not yet been well established. In the present study, an established mouse model of repeated social defeat stress (RSDS), was generated and used to investigate the effect of stress on tumor growth and metastasis. C57BL/6 mice were exposed to RSDS for 10 days, followed by subcutaneousl inoculation with Lewis lung carcinoma cells for seven days. The tumor weight and volume as well as the number of the lung metastatic nodules were then determined. Vascular endothelial growth factor (VEGF) serum levels were measured using ELISAs. In addition, expression levels of VEGF receptor (VEGFR) and L1 cell adhesion molecule (L1CAM) messenger (m)RNA were confirmed using reverse transcription quantitative polymerase chain reaction. Furthermore, protein expression levels of phosphorlyated extracellular signal-regulated kinase (pERK), matrix metalloproteinase (MMP)-2 and MMP-9 were examined using western blot analysis. The results showed that RSDS significantly increased the weight and the volume of the primary tumor as well as the number of the lung metastatic nodules. Serum VEGF levels were significantly higher in the tumor-stress group compared with those of the unstressed tumor mice. In addition, tumors in stressed animals demonstrated markedly enhanced expression of VEGFR-2 and L1CAM mRNA as well as pERK, MMP-2 and MMP-9 protein expression. In conclusion, these results suggested that RSDS contributed to lung cancer progression, angiogenesis and metastasis, which was partially associated with increased VEGF secretion and therefore the activation of the ERK signaling pathway, resulting in the induction of MMP-2 and MMP-9 protein expression.

Helicobacter pylori induces cell migration and invasion through casein kinase 2 in gastric epithelial cells

BACKGROUND

Chronic infection with Helicobacter pylori (H. pylori) is causally linked with gastric carcinogenesis. Virulent H. pylori strains deliver bacterial CagA into gastric epithelial cells. Induction of high motility and an elongated phenotype is considered to be CagA-dependent process. Casein kinase 2 plays a critical role in carcinogenesis through signaling pathways related to the epithelial mesenchymal transition. This study was aimed to investigate the effect of H. pylori infection on the casein kinase 2-mediated migration and invasion in gastric epithelial cells.

MATERIALS AND METHODS

AGS or MKN28 cells as human gastric epithelial cells and H. pylori strains Hp60190 (ATCC 49503, CagA(+)) and Hp8822 (CagA(-)) were used. Cells were infected with H. pylori at multiplicity of infection of 100 : 1 for various times. We measured in vitro kinase assay to examine casein kinase 2 activity and performed immunofluorescent staining to observe E-cadherin complex. We also examined β-catenin transactivation through promoter assay and MMP7 expression by real-time PCR and ELISA.

RESULTS

H. pylori upregulates casein kinase 2 activity and inhibition of casein kinase 2 in H. pylori-infected cells profoundly suppressed cell invasiveness and motility. We confirmed that casein kinase 2 mediates membranous α-catenin depletion through dissociation of the α-/β-catenin complex in H. pylori-infected cells. We also found that H. pylori induces β-catenin nuclear translocation and increases MMP7 expressions mediated through casein kinase 2.

CONCLUSIONS

We show for the first time that CagA(+) H. pylori upregulates cellular invasiveness and motility through casein kinase 2. The demonstration of a mechanistic interplay between H. pylori and casein kinase 2 provides important insights into the role of CagA(+) H. pylori in the gastric cancer invasion and metastasis.

Helicobacter pylori promotes epithelial-mesenchymal transition in gastric cancer by downregulating programmed cell death protein 4 (PDCD4)

Helicobacter pylori, a Gram-negative, microaerophilic bacterium found in the stomach, is assumed to be associated with carcinogenesis, invasion and metastasis in digestive diseases. Cytotoxin-associated gene A (CagA) is an oncogenic protein of H. pylori that is encoded by a Cag pathogenicity island related to the development of gastric cancer. The epithelial–mesenchymal transition (EMT) is the main biological event in invasion or metastasis of epithelial cells. H. pylori may promote EMT in human gastric cancer cell lines, but the specific mechanisms are still obscure. We explored the underlying molecular mechanism of EMT induced by H. pylori CagA in gastric cancer. In our article, we detected gastric cancer specimens and adjacent non-cancerous specimens by immunohistochemistry and found increased expression of the EMT-related regulatory protein TWIST1 and the mesenchymal marker vimentin in cancer tissues, while programmed cell death factor 4 (PDCD4) and the epithelial marker E-cadherin expression decreased in cancer specimens. These changes were associated with degree of tissue malignancy. In addition, PDCD4 and TWIST1 levels were related. In gastric cancer cells cocultured with CagA expression plasmid, CagA activated TWIST1 and vimentin expression, and inhibited E-cadherin expression by downregulating PDCD4. CagA also promoted mobility of gastric cancer cells by regulating PDCD4. Thus, H. pylori CagA induced EMT in gastric cancer cells, which reveals a new signaling pathway of EMT in gastric cancer cell lines.

Wound infections and healing: are they contributing factors for carcinogenesis?

The link between inflammation and tumourisation has long been considered as a key event in clinical cancer development. Inflammation and inflammatory diseases can be caused by many factors including infectious agents, altered genetics and various degrees of injuries from simple cuts to traumatic wounds, such as those suffered in battlefield. Improved management of all wound types is critical in protecting affected individuals against the development of tumourisation cues, which may potentially lead to cancer development. There have been numerous studies on the mechanism of inflammation-induced tumourisation. Thus, in this mini review, we summarised evidence demonstrating the potential link between infectious agents and their moonlight proteins, wounding, trauma, overactive repair mechanisms, and carcinogenesis.

Soluble a‑proliferation‑inducing ligand (sAPRIL), a novel serum biomarker predicting the recurrence and metastasis of pancreatic adenocarcinoma after surgery

Pancreatic adenocarcinoma (PA) is a leading cause of adult cancer mortality, and surgery is still the best available treatment strategy. However, PA can recur at any time and has limited prognosis. It is therefore necessary to explore novel serum biomarkers of PA to allow the early diagnosis of PA. Soluble a-proliferation-inducing ligand (sAPRIL), a promising inducer of the epithelial-mesenchymal transition (EMT), is often found overexpressed in a variety of autoimmune diseases. To determine whether serum sAPRIL can constitute a PA biomarker, the protein level of sAPRIL was examined by immunohistochemistry and western blot, and the mRNA level was quantified by RT-qPCR. The PA cell line PanC-1 was transfected with vectors bearing the sAPRIL gene and sAPRIL short hairpin RNA (shRNA) oligos. Increased expression of serum sAPRIL was observed in patients with PA recurrence or metastasis after five-year surgery compared to subjects without PA recurrence or metastasis. The growth rate of PanC-1 cells transfected with the sAPRIL expression vector was increased by 23% (P<0.01, vs. control group), and was reduced by 17% (P<0.01, vs. control group) in the sAPRIL shRNA-silenced cell line. Thus, sAPRIL is highly expressed in PA, and serum levels of sAPRIL can serve as a useful indicator for the recurrence or metastasis of PA after surgery. Additional validation studies on the use of serum sAPRIL as a diagnostic marker in PA are however needed.