Nature meets nurture: molecular genetics of gastric cancer. Hum Genet. 2009;126:615-628. [PMID: 19657673 PMCID: PMC2771140 DOI: 10.1007/s00439-009-0722-x]

Feasibility and Efficacy of Gastric Underwater Endoscopic Mucosal Resection

Gastric cancer, a leading cause of cancer-related deaths globally, necessitates effective and early detection and treatment strategies. Endoscopic resection techniques, particularly endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), have evolved significantly, enhancing the treatment of gastric neoplasms. Underwater endoscopic mucosal resection (UEMR) is a widely used technique for the resection of duodenal and colorectal neoplasms. However, the feasibility and efficacy of UEMR in the stomach are not well established. This retrospective observational study, conducted at a tertiary medical center, evaluated the efficacy and safety of UEMR in 81 patients with gastric neoplasms. Thus, it indicates that UEMR is a highly effective and safe technique for managing small to medium-sized gastric neoplasms, achieving 100% en bloc and 93.8% R0 resection rates with a low incidence of complications. Moreover, the procedure time was found to be significantly shorter for UEMR compared to ESD, thus highlighting its efficiency. While UEMR demonstrates high safety and efficacy, it is not suitable for all patients, with some requiring conversion to ESD as a treatment option. Despite the promising results, broader validation through extensive and randomized trials is recommended to establish UEMR as a standard approach in gastric cancer management.

Surface Markers for the Identification of Cancer Stem Cells

Cancer stem cells have genetic and functional characteristics which can turn them resistant to standard cancer therapeutic targets. Identification of these cells is challenging and is done mainly by detecting the expression of antigens specific to stem cells. Currently, there is a significant number of surface markers available which can detect cancer stem cells by directly targeting the specific antigens present in cells. These markers possess differential expression patterns and sub-localizations in cancer stem cells compared to nonneoplastic and somatic cells. In addition to these biomarkers, multiple analytical methods and techniques, including functional assays, cell sorting, filtration approaches, and xenotransplantation methods, are used to identify cancer stem cells. This chapter will overview the functional significance of cancer stem cells, their biological correlations, specific markers, and detection methods.

Epidemiology and Characteristics of Gastric Carcinoma in Childhood-An Analysis of Data from Population-Based and Clinical Cancer Registries

(1) Background: Gastric carcinoma is an exceptionally rare tumor in childhood. Little is known about the etiology, epidemiology, and clinical features of pediatric gastric carcinomas. This analysis aimed to fill this gap by increasing knowledge about the occurrence of gastric carcinoma in childhood. (2) Material and methods: Data from gastric carcinoma cases diagnosed between 2000 and 2017/2018 were retrieved from the Surveillance, Epidemiology, and End Results Program (SEER) and the German Center for Cancer Registry Data. Data from patients <20 years of age were analyzed for patient- and tumor-related characteristics. In addition, clinical data from patients with gastric carcinoma registered in the German Registry for Rare Pediatric Tumors (STEP) were analyzed for diagnostics, therapy, and outcome. (3) Results: Ninety-one cases of gastric carcinoma, mainly in adolescents, were identified in the epidemiologic cancer registries. Among patients with recorded staging data, advanced tumor stages were common (66.7%). Within the follow-up period covered, 63.7% of patients with clinical follow-up data died. Eight pediatric patients with gastric carcinoma were enrolled in the STEP registry, among whom two were patients with hereditary CDH1 mutations and another was a patient with Peutz−Jeghers syndrome. Three patients were found to have distinctly decreased immunoglobulin concentrations. All four patients in whom complete resection was achieved remained in remission. Three of the other four patients died despite multimodal therapy. (4) Conclusions: A combination of Helicobacter pylori infection and tumor predisposition and/or immunodeficiency appears to promote the development of gastric carcinoma in childhood. While patients with localized disease stages have a good chance of achieving durable remission through complete resection, patients with stage IV carcinomas face a dismal prognosis, highlighting the need to develop new strategies such as mutation-guided treatments.

MiR-711 regulates gastric cancer progression by targeting CD44

BACKGROUND

MicroRNAs (miRNAs) have been reported to play an important role in tumor progression by regulating the expression of target genes.

OBJECTIVE

This study attempted to verify the role of miR-711 in gastric cancer (GC) progression by in vitro and in vivo assays.

METHODS

The expression of miR-711 in tumor tissues and cells was detected by real-time quantitative PCR (qRT-PCR). Expression of MiR-711 in NCI-N87 and SNU-1 cells was detected by FISH. We transfected GC cells with miR-711 mimics or inhibitors. The effects of miR-711 on the proliferation and metastasis of GC cells were detected by CCK-8, wound healing and transwell assays. Dual-luciferase reporter gene assay was used to verify the targeting relationship between miR-711 and CD44. Xenograft assays was used to verify the regulatory effect of miR-711 on tumor growth.

RESULTS

In GC tissues and cell lines, the expression of miR-711 was down-regulated when compare with adjacent tissues or normal epithelial cells. The results indicated that overexpressing of miR-711 could suppress the GC cell proliferation, migration, and invasion through targeting CD44. The knockdown of CD44 showed similar effects as miR-711 overexpression in GC cells. Moreover, we confirmed these effects in the in vivo assays. Furthermore, we found that miR-711 could play a role by influencing tumor cell stemness.

CONCLUSION

MiR-711 plays vital roles as a tumor-suppressor by targeting CD44 and may be a therapeutic target for GC treatment.

Self-Renewal and Cancers of the Gastric Epithelium: An Update and the Role of the Lectin TFF1 as an Antral Tumor Suppressor

In 2020, gastric cancer was the fourth leading cause of cancer deaths globally. About 90% of gastric cancers are sporadic and the vast majority are correlated with Helicobacter pylori infection; whereas familial clustering is observed in about 10% of cases. Gastric cancer is now considered to be a disease originating from dysregulated self-renewal of the gastric glands in the setting of an inflammatory environment. The human stomach contains two types of gastric units, which show bi-directional self-renewal from a complex variety of stem cells. This review focuses on recent progress concerning the characterization of the different stem cell populations and the mainly mesenchymal signals triggering their stepwise differentiation as well as the genesis of pre-cancerous lesions and carcinogenesis. Furthermore, a model is presented (Lectin-triggered Receptor Blocking Hypothesis) explaining the role of the lectin TFF1 as an antral tumor suppressor possibly regulating Lgr5⁺ antral stem cells in a paracrine or maybe autocrine fashion, with neighboring antral gland cells having a role as niche cells.

Evaluation of Bax and BCL 2 Genes Polymorphisms in Iraqi Women with Breast Cancer

The present study aimed to examine the polymorphism -938C > A of BCL-2 gene and promoter -248G>A in the Bax gene, as well as their relationship with specific clinical-pathological characteristics, in patients with breast cancer. Blood samples were obtained from 70 patients who had been diagnosed with breast cancer and 34 healthy women as the control group. Polymorphic analysis was performed using the polymerase chain reaction-restriction fragment length polymorphism assay. Anthropometric data were assessed. Estrogen receptor (ER), human epidermal growth factor receptor 2 (Her-2),  and progesterone receptor (PR) were measured by immunohistochemistry. The data of age and body mass index (BMI) demonstrated no significant variations between the two groups (P>0.05). The results of HER-2 revealed that 42.86% of breast cancer patients reflected positively for Her-2/neu expression, while 24.29% reflected negative results of Her-2/neu. Moreover, the results of ER revealed that 42.86% and 28.57% of subjects were positive and negative ER, respectively; moreover, the missing data was 28.57%. In addition, the results of PR indicated that 35.71% of patients (25/70) were positive for PR, while 28.57% reflected negative results, and the missing results were 35.71%. The genotype and allele frequencies of BCL-2(-938C>A) were not statistically significant in women with breast cancer and the control group (P=0.574, P=0.533) for heterozygous and recessive models, respectively. The genotype of BCL-2(-938C>A) in control and patients in codominant, dominant, recessive, and additive models demonstrated no significant variations of all genotypes in all groups. Genotypes and allele frequencies for Bax (-248G>A) in patients with breast cancer and control indicated that the frequencies of GG, AG, and AA genotypes in cases were 16.67%, 3.33%, and 80 %, while in controls, these values were 3.23 %, 58.06 %, and 3.23 %, respectively. The heterozygous genotype (AG) in the codominant model was OR=36.00 (95% CI 4.5608 - 284.1608; P=0.0007). In comparison with the wild type (GG), there was a 36-fold increase in the risk of breast cancer. Furthermore, the findings of this study revealed a significant correlation between Bax (-248G>A) polymorphism and breast cancer risk under the dominant and overdominant (OR=6.33; 95% CI 2.2604 -17.7452; P=0.0004, and OR=40.154; 95% CI 5.1365 - 313.8949; P=0.0004, respectively. The recessive model revealed that there was a decreased risk of breast cancer (OR= 0.167; 95% CI 0.0303 to 0.9168; P=0.039). Based on the results, it can be concluded that there were no significant variations in BCL-2 (-938C>A) polymorphism of all genotypes models when breast cancer women are compared with healthy ones. In a similar vein, there was no significant association between the BCL-2 (-938C>A) polymorphism and breast cancer risk under dominant, codominant, or recessive models.

Application of Parametric Shared Frailty Models to Analyze Time-to-Death of Gastric Cancer Patients

BACKGROUND

Despite its declining incidence, gastric cancer (GC) is one of the world's leading malignancies and a major global health concern due to its high prevalence and fatality rate. Furthermore, it is the world's fourth most common cancer and the second leading cause of cancer death. Studying the determinants of time to death of gastric cancer patients will give clinicians more information to develop specific treatment plans, forecast prognosis, and track the progress of death cases. The application of the frailty model can help account for random variation in survival that may exist due to unobserved factors, as well as show the impact of latent factors on death risk. As a result, the purpose of this study was to assess the determinants of time to death of GC patients' by applying the parametric shared frailty models.

METHODS

The data for this study were obtained from gastric cancer patients admitted to the Tikur Anbesa Specialized Hospital, Addis Ababa, from January 1, 2015, to February 29, 2020. With the aim of coming up with an appropriate survival model that determines factors that affect the time to death of gastric cancer patients, various parametric shared frailty models were compared. In all of the frailty models, patient regions were used as a clustering variable. The current study implemented exponential, Weibull, log-logistic, and lognormal distributions for baseline hazard functions with gamma and inverse Gaussian's frailty distributions. The performance of all models was compared using the AIC and BIC criteria. R statistical software was used to conduct the analysis.

RESULTS

A retrospective study was undertaken on a total of 407 gastric cancer patients under follow-up at Tikur Anbesa Specialized Hospital. Of all 407 GC patients, 56.3% died while the remaining 43.7% were censored. The patients' median time to death was 21.9 months, with a maximum survival time of 49.6 months. In the current study, the clustering effect was significant in modeling the time to death from gastric cancer. The Weibull model with inverse Gaussian frailty has the minimum AIC and BIC value among the candidate models compared. The dependency within the clusters for the Weibull-inverse Gaussian frailty model was [Formula: see text] (13.4%). According to the results of our best model (Weibull-inverse Gaussian), the sex of the patient, the smoking status, the tumor size, the treatment taken, the vascular invasion, and the disease stage was found to be statistically significant at an alpha = 0.05 significance level.

CONCLUSION

Time to death of GC patient's data set was well described by the Weibull-inverse Gaussian shared frailty. Furthermore, Weibull baseline distribution best fits the GC data set as it enables proportional hazard and accelerated failure time model, for time to failure data. There is unobserved heterogeneity between clusters (patient regions), indicating the need to account for this clustering effect. In this study, survival time to death among GC patients was discovered to be small. Covariates like older age, being male, having higher (advanced) stage of GC disease (stage three and stage four), advanced tumor size, being smoker, infected by Helicobacter pylori, and existence of vascular invasion significantly accelerate the time to death of GC patients. In contrast, talking combination of more treatments prolongs the time to death of patients. To improve the health of patients, interventions should be taken based on significant prognostic factors, with special attention dedicated to patients with such factors to prevent GC death.

Index-based dietary patterns and stomach cancer in a Chinese population

OBJECTIVES

Dietary factors are of importance in the development of stomach cancer. This study aims to examine index-based dietary patterns associated with stomach cancer in a Chinese population.

METHODS

Using data from a population-based case-control study conducted in Jiangsu Province, China, we included a total of 8432 participants (1900 stomach cancer cases and 6532 controls). Dietary data collected by food frequency questionnaire was evaluated by modified Chinese Healthy Eating Index-2016 (mCHEI-2016) and the US Healthy Eating Index-2015 (HEI-2015). Multiple logistic regression analyses were applied to examine the association of mCHEI-2016 and HEI-2015 with stomach cancer while adjusting for potential confounders. The possible interactions between mCHEI-2016 or HEI-2015 and established risk factors were explored.

RESULTS

Among nonproxy interviews, after adjusting for potential confounding factors, a higher score of sodium, reflecting lower intake per day, was inversely associated with stomach cancer [odds ratio (OR), 0.95; 95% CI, 0.91-0.99 for mCHEI-2016; OR, 0.97; 95% CI, 0.94-0.99 for HEI-2015]. No clear associations with stomach cancer were identified for total scores of HEI-2015 (OR, 0.98; 95% CI, 0.87-1.10 with a 10-point increase, P trend = 0.98) and mCHEI-2016 (OR, 1.05; 95% CI, 0.94-1.17 with a 10-point increase, P trend = 0.22). However, the relation between stomach cancer and the mCHEI-2016 was modified by BMI, with a possible inverse association in normal-weight subjects.

CONCLUSIONS

Our findings highlight that reduced intake of dietary sodium would prevent the development of stomach cancer. The data indicate a heterogeneity between normal weight and overweight's dietary factors in relation to stomach cancer.

The feasibility and efficacy of perioperative auricular acupuncture technique via intradermal needle buried for postoperative movement-evoked pain after open radical gastrectomy: A randomized controlled pilot trial

INTRODUCTION

Auricular acupuncture is widely used in the treatment of pain. Recently, the most commonly used method of auricular acupuncture is to embed an intradermal needle into the skin to enhance analgesia through continuous stimulation. We aimed to explore the efficacy and feasibility of this form of auricular acupuncture in the treatment of postoperative movement-evoked pain.

METHODS

This single-blind randomized controlled pilot trial was conducted between 23/8/2019 and 10/1/2020. Forty patients were recruited and randomised to either the control group (n = 20) or the experimental group (n = 20). Patients in the control group received sham auricular acupuncture, while patients in the experimental group received auricular acupuncture. A standard routine analgesia was performed in both groups. The patients with NRS score≥4 were given rescue analgesia. Postoperative pain, use of opioids and other analgesics, postoperative recovery and patient's satisfaction were recorded.

RESULTS

The credibility and feasibility of auricular acupuncture for postoperative pain were high in both groups. After auricular acupuncture, the scores of the postoperative movement-evoked pain had a tendency to decrease, but no significant difference was observed between two groups at any time point (P = 0.234∼0.888). The data on postoperative pain at rest confirmed that no significant difference was observed between two groups within 48 h of surgery (P = 0.134∼0.520), and the postoperative pain at rest scores decreased over time; however, from the third day, the pain at rest scores of the experimental group were decreased, and significant differences were observed between the two groups (P = 0.039∼0.047). As for use of rescue analgesic, total opioid consumption and the incidence of postoperative nausea and vomiting, there were no significant differences between the two groups (P = 0.311, P = 0.101, P = 0.661) . In terms of patients' satisfaction, the score of the experimental group was higher than that of the control group, and a significant difference was observed between the two groups (P = 0.000). As for adverse events, two participants reported pain and one patient reported discomfort at the insertion sites during the process of auricular acupuncture intervention, but they both were minor and tolerable.

CONCLUSION

Auricular acupuncture may have a relief effect on mild postoperative pain at rest with pain score below 3, suggesting that it may be a feasible adjuvant method to relieve mild pain at rest. However, more multi-centre and large-sample studies are needed to verify this result.

HIF-Dependent Mechanisms of Relationship between Hypoxia Tolerance and Tumor Development

Oxygen deficiency is one of the key pathogenetic factors determining development and severity of many diseases, including inflammatory, infectious diseases, and cancer. Lack of oxygen activates the signaling pathway of the hypoxia-inducible transcription factor HIF in cells that has three isoforms, HIF-1, HIF-2, HIF-3, regulating expression of several thousand genes. Throughout tumor progression, HIF activation stimulates angiogenesis, promotes changes in cell metabolism, adhesion, invasiveness, and ability to metastasize. HIF isoforms can play opposite roles in the development of inflammatory and neoplastic processes. Humans and laboratory animals differ both in tolerance to hypoxia and in the levels of expression of HIF and HIF-dependent genes, which may lead to predisposition to the development of certain oncological disorders. In particular, the ratio of different histogenetic types of tumors may vary among people living in the mountains and at the sea level. However, despite the key role of hypoxia at almost all stages of tumor development, basal tolerance to oxygen deficiency is not considered as a factor of predisposition to the tumor growth initiation. In literature, there are many works characterizing the level of local hypoxia in various tumors, and suggesting fundamental approaches to its mitigation by HIF inhibition. HIF inhibitors, as a rule, have a systemic effect on the organism, however, basal tolerance of an organism to hypoxia as well as the level of HIF expression are not taken into account in the process of their use. The review summarizes the literature data on different HIF isoforms and their role in tumor progression, with extrapolation to organisms with high and low tolerance to hypoxia, as well as on the prevalence of various types of tumors in the populations living at high altitudes.

A Systematic Review of Artificial Intelligence Techniques in Cancer Prediction and Diagnosis

Artificial intelligence has aided in the advancement of healthcare research. The availability of open-source healthcare statistics has prompted researchers to create applications that aid cancer detection and prognosis. Deep learning and machine learning models provide a reliable, rapid, and effective solution to deal with such challenging diseases in these circumstances. PRISMA guidelines had been used to select the articles published on the web of science, EBSCO, and EMBASE between 2009 and 2021. In this study, we performed an efficient search and included the research articles that employed AI-based learning approaches for cancer prediction. A total of 185 papers are considered impactful for cancer prediction using conventional machine and deep learning-based classifications. In addition, the survey also deliberated the work done by the different researchers and highlighted the limitations of the existing literature, and performed the comparison using various parameters such as prediction rate, accuracy, sensitivity, specificity, dice score, detection rate, area undercover, precision, recall, and F1-score. Five investigations have been designed, and solutions to those were explored. Although multiple techniques recommended in the literature have achieved great prediction results, still cancer mortality has not been reduced. Thus, more extensive research to deal with the challenges in the area of cancer prediction is required.

Status of CHEK2 and p53 in patients with early-onset and conventional gastric cancer

Gastric cancer (GC) is the fourth most common cause of cancer-associated death. Based on the age at diagnosis, GC is divided into early-onset GC (EOGC; ≤45 years) and conventional GC (CGC; >45 years). Mutations in the cell cycle checkpoint kinase 2 (CHEK2) and TP53 genes are associated with several types of cancer; however, their genetic defects in GC remain poorly understood. The aim of the present study was to determine the subcellular distribution of the CHEK2 protein and its redistribution following DNA damage, to improve the understanding of the DNA damage response. Genetic alterations and patterns of expression of CHEK2 and p53 proteins were investigated to identify potential biological markers and indicators of GC development. Additionally, the affected signaling pathways and their clinical importance in GC development and associated syndromes were investigated. A total of 196 GC samples (89 CGC and 107 EOGC samples) were used in the present study. DNA from 53 samples (18 CGC and 35 EOGC samples) was sequenced using targeted next-generation sequencing technology to identify and compare common and rare mutations associated with GC. Subsequently, the cytoplasmic and nuclear expression levels of CHEK2, phosphorylated (p)-CHEK2 at threonine 68 and p53 in GC tissues were determined via immunohistochemistry. Sequencing resulted in the identification of 63 single nucleotide polymorphisms (SNPs) in the CHEK2 gene amongst 5 different variants, and the intron variant c.319+379A>G was the most common SNP. In the TP53 gene, 57 different alterations were detected amongst 9 variant types, and the missense variant c.215C>G was the most common. Nuclear CHEK2 expression was high in both the EOGC and CGC subtypes. However, the prevalence of cytoplasmic CHEK2 expression (P<0.001) and nuclear p-CHEK2 expression (P=0.011) was significantly higher in CGC compared with in EOGC tissues. There was a statistically significant difference between high and low cytoplasmic CHEK2 expression in patients with p53-positive EOGC compared with in patients with p53-positive CGC (P=0.002). The present study was designed to determine the association between CHEK2 and p53 expression patterns in patients with EOGC and CGC, as well as genetic alterations in the CHEK2 and TP53 genes.

A Mouse Model of Helicobacter pylori Infection

Infection with Helicobacter pylori (H. pylori) is of great distress because of its vital role in the pathogenesis of chronic gastritis, peptic ulcers, and in the multi-step carcinogenic process of gastric cancer. The increasing antibiotic resistance pattern of H. pylori worldwide has prompted the World Health Organization to put this organism in the priority pathogens list. To study the disease biology, evaluation of drugs, treatment outcome and to come up with probable vaccination strategies, competent animal models that reproduce the signature of human infection are essential. Initial reports about animal colonization with H. pylori have shown significant heterogeneity, to such an extent that Barry Marshall, Nobel laureate for the discovery of H. pylori , infected himself with the bacterium to show its involvement in acute gastric illness. A paradigm-shift discovery of the H. pylori mouse-adapted strain SS1 has opened the avenues of research regarding the organism and its pathogenicity. Although the mouse model of H. pylori infection is being utilized all over the world, there are certain issues that need awareness and specific information to achieve successful, consistent colonization with symptoms resembling human. This chapter details an established and reliable protocol for the development of a competent mouse model for H. pylori infection leading to various gastro-intestinal diseases.

Identification of subtype-specific genes signature by WGCNA for prognostic prediction in diffuse type gastric cancer

BACKGROUND

Gastric cancer is a common malignancy and had poor response to treatment due to its strong heterogeneity. This study aimed to identify essential genes associated with diffuse type gastric cancer and construct a powerful prognostic model.

RESULTS

We conducted a weighted gene co-expression network analysis (WGCN) using transcripts per million (TPM) expression data from The Cancer Genome Atlas (TCGA) to find out the module related with diffuse type gastric cancer. Combining Least Absolute Shrinkage and Selection Operator (LASSO) with multi-cox regression, the 10 specific genes risk score model of diffuse type gastric cancer was established. The concordance index (0.97), the area under the respective ROC curves (AUCs) (1-years: 0.98; 3-years: 1; 5-years: 1) and survival difference of high- and low risk groups (p=2.84e-10) of this model in TCGA dataset were obtained. The moderate predicting performance was observed in the independent cohort of GSE15459 and GSE62254. The results of the gene set enrichment analysis (GSEA) using high-and low risk group as phenotype indicated differential expression of tumor-related pathways.

CONCLUSION

Thus, we constructed a reliable prognostic model for diffuse type gastric cancer, which should be beneficial for clinical therapeutic decision-making.

Association between the methylation of the STAT1 and SOCS3 in peripheral blood and gastric cancer

BACKGROUND AND AIM

DNA methylation is an important epigenetic modification that can promote the development of various cancers. The STAT1 and SOCS3 have been observed to be hypermethylated in tumor tissues and peripheral blood. This study aimed to explore the relationship between the methylation status of the STAT1 and SOCS3 in peripheral blood and gastric cancer (GC).

METHODS

This hospital-based case-control study involved 372 patients with GC and 379 controls. The methylation status of the STAT1 and SOCS3 was semiquantitatively determined using the methylation-sensitive high-resolution melting method. Logistic regression analysis was used to analyze the relationship between the STAT1 and SOCS3 methylation status and GC susceptibility. Moreover, propensity scores were used to control confounding factors.

RESULTS

Compared with negative methylation, the positive methylation of SOCS3 significantly increased the risk of GC (OR_a  = 1.820, 95% CI: 1.247-2.658, P = 0.002). This trend was also found via stratified analysis, and methylation positivity of the SOCS3 significantly increased the risk of GC in the < 60 years group, in the ≥ 60 years group, and in the positive Helicobacter pylori infection group (OR_a  = 1.654, 95% CI: 1.029-2.660, P = 0.038; OR_a  = 1.957, 95% CI: 1.136-3.376, P = 0.016; OR_a  = 2.084, 95% CI: 1.270-3.422, P = 0.004, respectively). Additionally, no significant association was found between STAT1 methylation and GC risk (OR_a  = 0.646, 95% CI: 0.363-1.147, P = 0.135). This study found that the interaction between the methylation status of STAT1 and SOCS3 and environmental factors did not have an impact on GC risk.

CONCLUSION

SOCS3 methylation may serve as a new potential biomarker for GC susceptibility.

TTK regulates proliferation and apoptosis of gastric cancer cells through the Akt-mTOR pathway

TTK (also known as Mps1) is the core component of the spindle assembly checkpoint, which ensures proper distribution of chromosomes to daughter cells to maintain genome integrity and to balance growth and division. However, the function of TTK in tumorigenesis has not been extensively studied, especially in relation to the development of gastric cancer. In this study, survival and tumor recurrence data related to TTK expression level in gastric cancer patients were collected and analyzed. We observed that TTK expression was negatively correlated with survival and tumor recurrence in vivo. TTK was also upregulated in gastric cancer cells and was observed to be essential for the proliferation and survival of gastric cancer cells. Knockdown of TTK inhibited proliferation and increased apoptosis. Furthermore, we report that TTK regulates the proliferation and apoptosis of tumor cells through the Akt‐mTOR pathway. Knockdown of TTK inhibited activation of Akt‐mTOR signaling. In summary, our data indicate that TTK is involved in the regulation of gastric cancer proliferation and apoptosis.

Identifying specific miRNAs and associated mRNAs in CD44 and CD90 cancer stem cell subtypes in gastric cancer cell line SNU-5

Cancer stem cells (CSCs) are capable of generating multiple types of cells and play a vital role in promoting gastric cancer (GC) progression. Our previous research indicated that gastric CSCs with surface markers of CD44+ were more invasive compared to CD44- CD90+ CSCs (CD90+ CSCs), whereas CD90+ CSCs exhibited higher levels of proliferation than CD44+ CSCs. However, the mechanism and characteristics of marker-positive gastric CSCs are poorly understood. In this study, we profiled expression of miRNAs and mRNAs in CD44+ CSCs, CD90+ CSCs, and CD44- CD90- cell subtype (control) from SNU-5 cells by microarray analysis. Our results suggested some specially expressed miRNA-mRNA pairs in CD44+ and CD90+ CSCs. We performed Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses to analyze the correlation and function of those pairs. We also validated the pairs that may play roles in metastasis by qRT-PCR. In CD44+ CSCs, we observed hsa-miR-15b-5p was up-regulated and its target genes AMOT, USP31, KALRN, EPB41L4B, ATP2B2, and EMC4 were down-regulated, which may relate to invasion and migration. In CD90+ CSCs, we observed hsa-miR-3631-3p is up-regulated, while its target genes QKI, TRIM67 and HMGA2 are down-regulated, which is associated with proliferation. We also found that hsa-miR-1910-5p is up-regulated while its target gene QKI and HMGA2 are down-regulated in CD90+ CSCs. The screened miRNA-mRNA pairs give us new insight into the mechanism of different phenotypes and biomarkers capable of identifying and isolating metastatic and tumorigenic CSCs. Those miRNA-mRNA pairs may also act as treatment for GC.

microRNA-665 is down-regulated in gastric cancer and inhibits proliferation, invasion, and EMT by targeting PPP2R2A

Recently, microRNA-665 (miR-665) has been reported to function as both tumour suppressor and oncogene in several cancer types, including gastric cancer, hepatocellular cancer, and lung cancer. However, the biological function of miR-665 and its precise mechanisms in gastric cancer (GC) have not been well clarified. The aim of this study was to study the roles of miR-665/PPP2R2A axis in GC. The levels of PPP2R2A and miR-665 were detected by quantitative PCR assay in GC tissues and cell lines. Moreover, the biological roles of miR-665 and PPP2R2A in GC cells were assessed by cell proliferation, invasion, and epithelial-mesenchymal transition (EMT). The mRNA and protein levels of PPP2R2A were determined by using quantitative PCR and Western blotting assays. Luciferase assays were used to confirm that PPP2R2A was one target of miR-665. In this study, the miR-665 level was dramatically reduced in GC tissues and cell lines, and the PPP2R2A expression was significantly enhanced. What is more, the PPP2R2A expression was negatively related to the miR-665 level in GC tissues. Furthermore, up-regulation of miR-665 obviously restrained GC cells proliferation, invasion, and EMT. We confirmed that miR-665 could directly target PPP2R2A by luciferase reporter assay. Besides, knockdown of PPP2R2A also could markedly inhibit the proliferation, invasion and EMT of GC cells. Finally, overexpression of miR-665 in GC cells partially reversed the promoted effects of PPP2R2A up-regulation. Overexpression of miR-665 restrained GC cells proliferation, invasion and EMT via regulation of PPP2R2A. SIGNIFICANCE OF THE STUDY:  miR-665 has been reported to function as oncogene or tumour suppressor in different cancers. However, the precise roles of miR-665 in GC have not been elucidated. Our study for the first time demonstrated that miR-665 level was significantly down-regulated in GC. Additionally, miR-665 overexpression inhibited cell growth, invasion, and EMT of GC. Moreover, our data suggested a significant negative correlation between miR-665 and PPP2R2A expression in GC. MiR-665 suppressed GC cell proliferation, invasion, and EMT by directly targeting PPP2R2A, which suggested important roles for miR-665/PPP2R2A axis in the GC pathogenesis and its potential application in cancer therapy.

S100P is a molecular determinant of E-cadherin function in gastric cancer

Background

E-cadherin has been awarded a key role in the aetiology of both sporadic and hereditary forms of gastric cancer. In this study, we aimed to identify molecular interactors that influence the expression and function of E-cadherin associated to cancer.

Methods

A data mining approach was used to predict stomach-specific candidate genes, uncovering S100P as a key candidate. The role of S100P was evaluated through in vitro functional assays and its expression was studied in a gastric cancer tissue microarray (TMA).

Results

S100P was found to contribute to a cancer pathway dependent on the context of E-cadherin function. In particular, we demonstrated that S100P acts as an E-cadherin positive regulator in a wild-type E-cadherin context, and its inhibition results in decreased E-cadherin expression and function. In contrast, S100P is likely to be a pro-survival factor in gastric cancer cells with loss of functional E-cadherin, contributing to an oncogenic molecular program. Moreover, expression analysis in a gastric cancer TMA revealed that S100P expression impacts negatively among patients bearing Ecad⁻ tumours, despite not being significantly associated with overall survival on its own.

Conclusions

We propose that S100P has a dual role in gastric cancer, acting as an oncogenic factor in the context of E-cadherin loss and as a tumour suppressor in a functional E-cadherin setting. The discovery of antagonist effects of S100P in different E-cadherin contexts will aid in the stratification of gastric cancer patients who may benefit from S100P-targeted therapies.

Graphical abstract

lncRNA UCA1 Predicts a Poor Prognosis and Regulates Cell Proliferation and Migration by Repressing p21 and SPRY1 Expression in GC

Dysregulated expression of long non-coding RNAs (lncRNAs) has been reported in many types of cancers, indicating that it has important regulatory roles in human cancer biology. Recently, lncRNA urothelial cancer-associated 1 (UCA1) was shown to be dysregulated in many cancer types, but the detailed mechanisms remain largely unknown. In our study, we found that upregulated UCA1 is associated with poor prognosis in gastric cancer patients. Further experiments revealed that UCA1 knockdown significantly repressed the proliferation and migration both in vitro and in vivo. Moreover, RNA sequencing (RNA-seq) analysis revealed that UCA1 knockdown preferentially affected genes that are linked to cell proliferation, cell cycle, and cell migration. Mechanistically, UCA1 promotes cell proliferation progression through repressing p21 and Sprouty RTK signaling antagonist 1 (SPRY1) expression by binding to EZH2. We found that UCA1 could mediate the trimethylation of H3K27 in promoters of p21 and SPRY1. To our knowledge, this is the first report showing the global gene profile of downstream targets of UCA1 in the progression of gastric cancer. Collectively, our data reveal the important roles of UCA1 in gastric cancer (GC) oncogenesis.

MicroRNA-383-5p inhibits the progression of gastric carcinoma via targeting HDAC9 expression

MicroRNAs (miRNAs), as post-transcriptional regulators, have been reported to be involved in the initiation and progression of various types of cancer, including gastric cancer (GC). The present study aimed to investigate the role of miR-383-5p in gastric carcinogenesis. Cell viability was analyzed using CCK-8 kit. Annexin V-fluorescein isothiocyanate/propidium iodide double staining was used to evaluate cell apoptosis. The expression levels of miR-383-5p and histone deacetylase 9 (HDAC9) mRNA in GC tissues and cell lines were analyzed using RT-qPCR. The protein expression of HDAC9 was detected by western blotting. We found that HDAC9 was up-regulated and miR-383-5p was down-regulated in GC tissues and cell lines. High HDAC9 expression or low miR-383-5p expression was closely related to poor prognosis and metastasis in GC patients. HDAC9 knockout or miR-383-5p mimics led to growth inhibition and increased apoptosis in AGS and SGC-7901 cells. More importantly, we validated that miR-383-5p as a post-transcriptional regulator inhibited HDAC9 expression and was inversely correlated with HDAC9 expression in GC tissues. miR-383-5p had the opposite effects to HDAC9 in gastric carcinogenesis. miR-383-5p played an important role in gastric carcinogenesis, and it is one of the important mechanisms to regulate oncogenic HDAC9 in GC, which might be helpful in the development of novel therapeutic strategies for the treatment of GC.

MTSS1 inhibits metastatic potential and induces G2/M phase cell cycle arrest in gastric cancer

Background: Metastasis suppressor 1 (MTSS1), a potential metastasis suppressor gene associated with tumor progression, may play an important role in cancer development. Our previous study demonstrated that MTSS1 was downregulated significantly when gastric cancer (GC) progressed and metastasized, suggesting that MTSS1 may be involved in the physiopathologic mechanism of GC.

Purpose: The objective of this study was to evaluate the effect of MTSS1 expression on the biological behavior of gastric cancer cell both in vitro and in vivo.

Materials and methods: The gain-and-loss function of MTSS1 in GC cells were analyzed after transfection with pEGFP-N1-MTSS1 and ShRNA431. Proliferation and invasion abilities were measured by means of plate clone formation assay and transwell assay. To further explore the underlying mechanism of MTSS1-induced tumor restrain, cell cycle distribution was analyzed using flow cytometry.

Results: The results revealed that overexpression of MTSS1 significantly reduced proliferation, migration and invasion of GC cells in vivo and in vitro, while downregulation of MTSS1 had the opposite biological manifestations. Moreover, overexpression of MTSS1 induced accumulation of GC cells in G2/M phase, increased phosphorylated Cdc2 expression and decreased Cdc25C and cyclinB1 levels, suggesting MTSS1 could cause G2/M cell cycle arrest.

Conclusion: Our data provided insight into an important role for MTSS1 in suppressing tumor cell proliferation, invasion and migration, indicating that MTSS, as a functional tumor suppressor in GC, could be a potential therapeutic target to prevent GC metastasis.

Molecular Diagnostics in Esophageal and Gastric Neoplasms: 2018 Update

Esophageal cancer (EC) is rapidly increasing in incidence in the United States. Genetic changes associated with the development of EC involve the p16, p53, and APC genes. Human epidermal growth factor 2 (HER-2) overexpression is seen in gastroesophageal junction carcinoma and a subset gastric carcinoma (GC). Interestingly, up to 50% cases of GC are related to Helicobacter pylori infection and up to 16% are related to EBV infection. Microsatellite instability is observed in up to 39% of GC and cell free nucleic acid analysis provides additional opportunities for diagnosis and prognosis of disease.

Association between Polymorphisms in Inflammatory Response-Related Genes and the Susceptibility, Progression and Prognosis of the Diffuse Histological Subtype of Gastric Cancer

The chronic inflammatory microenvironment and immune cell dysfunction have been described as critical components for gastric tumor initiation and progression. The diffuse subtype is related to poor clinical outcomes, pronounced inflammation, and the worst prognosis. We investigated the association of polymorphisms in inflammatory response-related genes (COX-2, OGG1, TNFB, TNFA, HSPA1L, HSPA1B, VEGFA, IL17F, LGALS3, PHB, and TP53) with gastric cancer susceptibility, progression and prognosis in a Brazilian sample, focusing on the diffuse subtype. We also performed the analysis regarding the total sample of cases (not stratified for tumor subtypes), allowing the comparison between the findings. We further investigated the polymorphisms in linkage disequilibrium and performed haplotype association analyses. In the case-control study, rs1042522 (TP53) was associated with a stronger risk for developing gastric cancer in the sample stratified for diffuse subtype patients when compared to the risk observed for the total cases; CTC haplotype (rs699947/rs833061/rs2010963 VEGFA) was associated with risk while rs699947 was associated with protection for gastric malignancy in the total sample. Regarding the associations with the clinicopathological features of gastric cancer, for the diffuse subtype we found that rs699947 and rs833061 (VEGFA) were associated with outcomes related to a worse progression while rs5275 (COX-2), rs909253 (TNFB), and rs2227956 (HSPA1L) were associated to a better progression of the disease. In the total sample, rs699947 and rs833061 (VEGFA), rs4644 (LGALS3), and rs1042522 (TP53) were able to predict a worse progression while rs5275 (COX-2), rs2227956 (HSPA1L), and rs3025039 (VEGFA) a better progression. Besides, rs909253 (TNFB) predicted protection for the overall and disease-free survivals for gastric cancer. In conclusion, these results helped us to clarify the potential role of these polymorphisms in genes involved in the modulation of the inflammatory response in the pathogenesis of gastric cancer.

Potential role of Toll-like receptor 2 expression and polymorphisms in colon cancer susceptibility in the Saudi Arabian population

Background

Inflammation is a fundamental factor that contributes to the development and progression of several types of cancer including colon cancer. Toll-like receptors (TLRs) and their signaling pathways have been reported to be associated with chronic inflammation and thereby induced cancer. Our aim was to investigate the expression and polymorphisms of TLR2 and their association with colon cancer.

Methods

Real-time PCR and immunohistochemistry were used to investigate TLR2 gene expression and to evaluate the potential risk of predisposition to colon cancer caused by three tagging single-nucleotide polymorphisms (SNPs) on TLR2, including rs3804100, rs4696480, and rs3804099. TaqMan assay was conducted on samples from 115 patients with colon cancer and 102 age- and sex-matched normal individuals.

Results

We found that, TLR2 was highly expressed in epithelial colon cancer cells and both TLR2 mRNA and protein levels, and significantly decreased in tumor tissues compared to normal tissues. Two of three TLR2 SNPs increased the risk of colon cancer. However, TLR2 rs3804099 increased the risk of colon cancer development by more than 3.8- and 5-fold in female patients and patients aged less than 57 years, respectively. The T allele of TLR2 rs3804100 showed a significant association with patients less than 57 years. In silico analysis of the TLR2 nucleotide substitution in SNP rs3804100 and rs3804099 determined that 67% and 70% probability of these single nucleotide variants alter splicing phenotypes, rs3804100 more specifically result on activating an additional splice site. Genotype and allele frequencies of rs4696480 were similar between the overall study populations. Thus, TLR2 rs4696480 appear to be not involved in colon cancer in our study population.

Conclusions

There was a significant link between innate immunity deregulation through disruption of the TLRs and potential development of colon cancer. These SNPs can be used as screening markers for predicting colon cancer risk earlier in life to implement necessary prevention.

A study on the correlation of MyD88 expression with gastric cancer

OBJECTIVE

The myeloid differentiation factor-88 (MyD88) plays a key role in mediating the innate immune signal transduction of toll-like receptor (TLR) and interleukin-1 (IL-1) family members, and it also participates in the regulation of tumorigenesis in various cancer models Our study sought to determine whether there is any correlation with MyD88 and the development of gastric cancer and, if such a correlation exists, to find out whether it can be used to improve the prognosis of gastric cancer patients.

PATIENTS AND METHODS

The expression of MyD88 in 108 cases of gastric cancer specimens, 15 cases of adenoma, and 15 cases of normal mucosa was detected by immunohistochemistry, and the correlations of the MyD88 expression with clinicopathologic changes (including disease-free survival [DFS] and overall survival [OS] were analyzed. The level of MyD88 was detected in well-differentiated MGC-803 and poorly-differentiated BGC-823 cell lines by qPCR and western blot. The expression of MyD88 was then measured by western blot after the treatment of an MyD88 overexpression vector or MyD88 inhibitor. Cell proliferation was determined by overexpression or suppression of MyD88.

RESULTS

In clinical cases, MyD88 was highly expressed in 23% of patients with gastric cancer as compared to those in normal mucosa and adenoma. There was a significant correlation of MyD88 overexpression with gastric metastasis (P<0.01). The overexpression of MyD88 significantly promoted the proliferation of MGC-803 and BGC-823 cell lines in gastric cancer. According to the single factor analysis, a high expression of MyD88 was strongly associated with poor DFS and OS (P<0.01), and MyD88 was an independent prognostic factor of OS.

CONCLUSION

This study demonstrates that a high expression of MyD88 is associated with the gastric cancer patients with liver metastasis, and facilitates the proliferation of gastric cancer cells. MyD88 is an independent predictive factor for the poor prognosis of gastric cancer patients, which provides a potential tool for future clinical diagnosis.

High FNDC1 expression correlates with poor prognosis in gastric cancer

Gastric cancer is a common human cancer worldwide. Fibronectin is an important extracellular matrix protein that has been implicated in many cancers and is known to be associated with proliferation and migration. Fibronectin type III domain containing 1 (FNDC1) contains a major component of the structural domain of fibronectin. The objectives of the present study were to measure FNDC1 expression in gastric cancer tissues and evaluate its value as a potential prognostic marker for gastric cancer. FNDC1 protein expression was analyzed by immunohistochemistry in 98 samples of gastric cancer tissue and 25 adjacent normal tissues. The associations between FNDC1 level and various clinicopathological characteristics were assessed, and the correlation between FNDC1 expression levels and prognosis of patients with gastric cancer was analyzed using a Kaplan-Meier analysis. It was demonstrated that FNDC1 expression in gastric cancer tissues and adjacent tissues was significantly different. FNDC1 expression levels were significantly higher in gastric cancer tissues compared with normal gastric tissues (P<0.001). Among the clinicopathological characteristics evaluated, clinical stage (P<0.001), T classification (P<0.001), N classification (P<0.001) and pathological differentiation (P=0.044) were significantly associated with high FNDC1 expression. Higher FNDC1 expression level was significantly correlated with poorer survival. The present findings suggest that FNDC1 expression levels may be a promising prognostic biomarker for gastric cancer.

Genetic variants in PI3K/Akt/mTOR pathway genes contribute to gastric cancer risk

PI3K/Akt/mTOR pathway is involved in tumor initiation and progression, including gastric cancer (GC). However, the single nucleotide polymorphisms (SNPs) in this pathway and underlying molecular mechanism remain largely unexplored. A case-control study of 1275 GC patients and 1436 controls was performed to explore the associations of potentially functional SNPs in PI3K/Akt/mTOR pathway genes with the risk of GC. In the logistic regression analyses, one SNP rs7536272 out of the four candidate SNPs showed a significant association with GC risk (additive model: OR = 1.16, 95% CI = 1.03-1.30; co-dominant model: AG vs. AA, OR = 1.30, 95% CI = 1.11-1.53; dominant model: AG/GG vs. AA, OR = 1.28, 95% CI = 1.10-1.49).The luciferase assay indicated that rs7536272 G allele significantly enhanced the transcriptional activity, compared with A allele. Further expression quantitative trait loci (eQTL) analysis showed that GC patients with rs7536272 AG/GG genotypes had remarkably higher PIK3R3 levels than those with AA genotype, suggesting that rs7536272 polymorphism influenced the expression of PIK3R3. Additionally, we observed that GC patients with high expression of PIK3R3 had significant poorer outcome than those with low expression (HR = 1.29, 95% CI = 1.09-1.53). Our result demonstrated that SNP rs7536272, a functional risk variant located in the promoter region of PIK3R3, showed association with increased transcriptional activity and upregulation of PIK3R3 expression, thus involved in GC development.

Multi‑layered prevention and treatment of chronic inflammation, organ fibrosis and cancer associated with canonical WNT/β‑catenin signaling activation (Review)

β-catenin/CTNNB1 is an intracellular scaffold protein that interacts with adhesion molecules (E-cadherin/CDH1, N-cadherin/CDH2, VE-cadherin/CDH5 and α-catenins), transmembrane-type mucins (MUC1/CD227 and MUC16/CA125), signaling regulators (APC, AXIN1, AXIN2 and NHERF1/EBP50) and epigenetic or transcriptional regulators (BCL9, BCL9L, CREBBP/CBP, EP300/p300, FOXM1, MED12, SMARCA4/BRG1 and TCF/LEF). Gain-of-function CTTNB1 mutations are detected in bladder cancer, colorectal cancer, gastric cancer, liver cancer, lung cancer, pancreatic cancer, prostate cancer and uterine cancer, whereas loss-of-function CTNNB1 mutations are also detected in human cancer. ABCB1, ALDH1A1, ASCL2, ATF3, AXIN2, BAMBI, CCND1, CD44, CLDN1, CTLA4, DKK1, EDN1, EOMES, FGF18, FGF20, FZD7, IL10, JAG1, LEF1, LGR5, MITF, MSX1, MYC, NEUROD1, NKD1, NODAL, NOTCH2, NOTUM, NRCAM, OPN, PAX3, PPARD, PTGS2, RNF43, SNAI1, SP5, TCF7, TERT, TNFRSF19, VEGFA and ZNRF3 are representative β-catenin target genes. β-catenin signaling is involved in myofibroblast activation and subsequent pulmonary fibrosis, in addition to other types of fibrosis. β-catenin and NF-κB signaling activation are involved in field cancerization in the stomach associated with Helicobacter pylori (H. pylori) infection and in the liver associated with hepatitis C virus (HCV) infection and other etiologies. β-catenin-targeted therapeutics are functionally classified into β-catenin inhibitors targeting upstream regulators (AZ1366, ETC-159, G007-LK, GNF6231, ipafricept, NVP-TNKS656, rosmantuzumab, vantictumab, WNT-C59, WNT974 and XAV939), β-catenin inhibitors targeting protein-protein interactions (CGP049090, CWP232228, E7386, ICG-001, LF3 and PRI-724), β-catenin inhibitors targeting epigenetic regulators (PKF118-310), β-catenin inhibitors targeting mediator complexes (CCT251545 and cortistatin A) and β-catenin inhibitors targeting transmembrane-type transcriptional outputs, including CD44v6, FZD7 and LGR5. Eradicating H. pylori and HCV is the optimal approach for the first-line prevention of gastric cancer and hepatocellular carcinoma (HCC), respectively. However, β-catenin inhibitors may be applicable for the prevention of organ fibrosis, second-line HCC prevention and treating β-catenin-driven cancer. The multi-layered prevention and treatment strategy of β-catenin-related human diseases is necessary for the practice of personalized medicine and implementation of precision medicine.

Long non-coding RNA GPR65-1 is up-regulated in gastric cancer and promotes tumor growth through the PTEN-AKT-slug signaling pathway

Increasing evidence has shown that abnormal expression of lncRNAs is involved in various biological behaviors and major cellular pathways of human cancers. However, the role of lncRNAs in the progression of gastric cancer has not been adequately investigated. Therefore, in this study, we investigated the expression levels of linc-GPR65-1 using Quantitative real-time PCR (qRT-PCR) and found that linc-GPR65-1 was significantly up-regulated in 50 gastric cancer tissues compared to the corresponding normal tissues. In addition, increased linc-GPR65-1 expression was associated with TNM stage (P = 0.037), tumor size (P = 0.024), distal metastasis (P = 0.023), and poor prognosis of gastric cancer patients. Moreover, functional assays indicated that decreased linc-GPR65-1 expression inhibited the aggressive phenotypes of gastric cancer cells, and enhanced linc-GPR65-1 expression resulted in the opposite phenomenon. Then, a cancer signaling phosphoantibody microarray was conducted to explore the potential mechanisms of linc-GPR65-1 in regulating gastric cancer progression and observed that linc-GPR65-1 could regulate the PTEN-AKT-slug signaling pathway. These data showed that linc-GPR65-1, regulating the PTEN-AKT-slug signaling pathway, might act as a tumor promoter and serve as a novel target for gastric cancer prevention and therapy.

High density of CD68+ tumor-associated macrophages predicts a poor prognosis in gastric cancer mediated by IL-6 expression

The aim of the present study was to explore the potential role of cluster of differentiation CD68+ tumor-associated macrophages (TAMs) induced by interleukin (IL)-6 in the progression of gastric cancer (GC) and patient prognosis. The expression levels of IL-6 and CD68 were detected by immunohistochemical staining in 60 samples of tumor and non-tumor gastric tissues. CD14+ monocytes were isolated from peripheral blood mononuclear cells and stimulated with macrophage colony stimulation factor (M-CSF) and IL-6, and the expression levels of IL-10, IL-12, vascular endothelial growth factor (VEGF)-C and transforming growth factor (TGF)-β were measured by reverse transcription polymerase chain reaction and ELISA. The GC MGC-803 cell line was co-cultured with monocytes stimulated by M-CSF and IL-6 and the invasion ability of the MGC-803 was evaluated by Transwell analysis. The levels of STAT3, P-STAT3 and interferon-regulatory factor 4 (IRF4) in the monocytes stimulated by M-CSF and IL-6 were detected by western blotting. The results demonstrated that the frequencies of IL-6+ macrophages (Mφs) and CD68+ Mφs were significantly higher in tumor regions compared with the corresponding non-tumor regions of GC tissues. Kaplan-Meier analysis revealed that the densities of tumor-infiltrating CD68+ or IL-6+ Mφs were inversely associated with the overall survival rates of the patients. In vitro, the expression levels of IL-10, VEGF-C and TGF-β significantly increased in CD14+ monocytes subsequent to M-CSF and IL-6 stimulation. The invasion abilities of MGC-803 were increased by the monocytes stimulated with M-CSF and IL-6. The levels of STAT3, P-STAT3 and IRF4 proteins increased in the monocytes stimulated by M-CSF and IL-6. In conclusion, the results from the present study suggest that a high density of CD68+ TAMs predicts a poor prognosis in GC. IL-6 may polarize the Mφs and promote tumor invasion through the IL-6/STAT3/IRF4 signaling pathway.

Gelsolin-mediated activation of PI3K/Akt pathway is crucial for hepatocyte growth factor-induced cell scattering in gastric carcinoma

In gastric cancer (GC), the main subtypes (diffuse and intestinal types) differ in pathological characteristics, with diffuse GC exhibiting early disseminative and invasive behaviour. A distinctive feature of diffuse GC is loss of intercellular adhesion. Although widely attributed to mutations in the CDH1 gene encoding E-cadherin, a significant percentage of diffuse GC do not harbor CDH1 mutations. We found that the expression of the actin-modulating cytoskeletal protein, gelsolin, is significantly higher in diffuse-type compared to intestinal-type GCs, using immunohistochemical and microarray analysis. Furthermore, in GCs with wild-type CDH1, gelsolin expression correlated inversely with CDH1 gene expression. Downregulating gelsolin using siRNA in GC cells enhanced intercellular adhesion and E-cadherin expression, and reduced invasive capacity. Interestingly, hepatocyte growth factor (HGF) induced increased gelsolin expression, and gelsolin was essential for HGF-medicated cell scattering and E-cadherin transcriptional repression through Snail, Twist and Zeb2. The HGF-dependent effect on E-cadherin was found to be mediated by interactions between gelsolin and PI3K-Akt signaling. This study reveals for the first time a function of gelsolin in the HGF/cMet oncogenic pathway, which leads to E-cadherin repression and cell scattering in gastric cancer. Our study highlights gelsolin as an important pro-disseminative factor contributing to the aggressive phenotype of diffuse GC.

Associations of potentially functional variants in IL-6, JAKs and STAT3 with gastric cancer risk in an eastern Chinese population

The interleukin-6 (IL-6)/JAK/STAT3 signaling pathway plays a central role in inflammation-mediated cancers, including gastric cancer (GCa). We evaluated associations between 10 potentially functional single nucleotide polymorphisms (SNPs) of four essential genes in the pathway and GCa risk in a study of 1,125 GCa cases and 1,221 cancer-free controls. We found that a significant higher GCa risk was associated with IL-6 rs2069837G variant genotypes [adjusted odds ratios (OR) = 1.33; 95% confidence interval (CI) = 1.12-1.59 for AG + GG vs. AA)] and JAK1 rs2230587A variant genotypes (adjusted OR = 1.20; 95% CI = 1.02-1.43 for GA + AA vs. GG). We also found that a significant decreased GCa risk was associated with STAT3 rs1053004G variant genotypes (adjusted OR = 0.84; 95% CI = 0.71-0.99 for AG + GG vs. AA). The combined analysis of IL-6 rs2069837G and JAK1 rs2230587A variant risk genotypes revealed that individuals with one-or-two risk genotypes exhibited an increased risk for GCa (adjusted OR = 1.34; 95% CI = 1.13-1.59). Genotypes and mRNA expression correlation analysis using the data from the HapMap 3 database provided further support for the observed risk associations. Larger studies are warranted to validate these findings.

Surface Markers for the Identification of Cancer Stem Cells

Cancer stem cells have genetic and functional characteristics that can turn them resistant to standard cancer therapeutic targets. Identification of these cells is challenging and is mostly done by detecting the expression of their antigens in a group of stem cells. Currently, there are a significant number of surface markers available which can detect the cancer stem cells by directly targeting their specific antigens present in cells. These markers possess differential expression patterns and sub-localizations in cancer stem cells when compared to non-neoplastic stem cells and somatic cells. In addition to molecular markers, multiple analytical methods and techniques including functional assays, cell sorting, filtration approaches, and xenotransplantation methods are used to identify cancer stem cells. This chapter will overview the functional significance of cancer stem cells, its biological correlations, specific markers, and detection methods.

Single nucleotide polymorphisms rs911160 in AURKA and rs2289590 in AURKB mitotic checkpoint genes contribute to gastric cancer susceptibility

BACKGROUND

Single nucleotide polymorphisms (SNPs) in mitotic checkpoint genes could confer increased susceptibility to gastric cancer (GC). We investigated the association of Aurora kinase A (AURKA), Aurora kinase B (AURKB), Aurora kinase C (AURKC), Polo-like kinase 1 (PLK1) and Budding uninhibited by benzimidazol 3, yeast (BUB3) gene polymorphisms with GC risk.

MATERIALS AND METHODS

Genotyping of 6 SNPs in AURKA (rs911160 and rs8173), AURKB (rs2289590), AURKC (rs11084490), PLK1 (rs42873), and BUB3 (rs7897156) was performed using TaqMan genotyping assays.

RESULTS

Our study demonstrated that rs911160 (AURKA) heterozygous genotype was associated with an increased GC risk (OR = 1.50, 95% CI = 1.01-2.22, P = 0.043). Analysis of rs911160 (AURKA) showed significant association with an increased risk for intestinal type GC (OR = 1.80, 95%CI = 1.01-3.21, P = 0.040) and the risk was significantly higher in women than men (OR = 2.65, 95%CI = 1.02-6.87, P = 0.033). SNP rs2289590 in AURKB might contribute to susceptibility for the development of gastric cancer, particularly in women (OR = 2.08, 95% CI = 1.05-4.09, P = 0.032).

CONCLUSION

Our findings suggested that AURKA (rs911160) and AURKB (rs2289590) polymorphisms could affect GC risk. Further validation studies in larger and multi-ethnical populations are needed to elucidate their functional impact on the development of GC. Environ. Mol. Mutagen. 58:701-711, 2017. © 2017 Wiley Periodicals, Inc.

Aquaporin 3 promotes the stem-like properties of gastric cancer cells via Wnt/GSK-3β/β-catenin pathway

Cancer stem cells (CSCs) are believed to contribute to the tumor growth in gastric carcinoma (GC), a common lethal malignancy. This study investigated the effect of aquaporin 3 (AQP3) on stem-like properties of human GC cells. Elevated AQP3 expression was associated with CD44 expression in human GC specimens. Expression of AQP3 and that of CD44 positively correlated with Lauren classification, lymph node metastasis, and lymphovascular invasion. Altering the AQP3 expression had pronounced effects on the tumorigenic potential and self-renewal capacity of the gastric cancer cell lines SGC7901, MGC803, and AGS, both in vitro and in vivo. Overexpression of AQP3 induced CD44 expression and activation of the β-catenin signaling pathway, whereas silencing AQP3 expression using short hairpin RNA had the opposite effect. Furthermore, pharmacological inhibition of GSK-3β using LiCl impaired the effect of AQP3 knockdown in CSCs, whereas the inhibition of the Wnt/β-catenin pathway by XAV939 blocked the effect of AQP3 overexpression. These results demonstrate that AQP3 promotes stem-like properties of human GC cells by activating the Wnt/GSK-3β/β-catenin signaling pathway.

Effects of Soy Product Intake and Interleukin Genetic Polymorphisms on Early Gastric Cancer Risk in Korea: A Case-Control Study

PURPOSE

The current study investigated whether the combined effects of soy intake and genetic polymorphisms of interleukin (IL) genes modify gastric cancer risk.

MATERIALS AND METHODS

A total of 377 cases and 754 controls of Korean origin were included in the analysis. Soy consumption was assessed using a semi-quantitative food frequency questionnaire. Seven variants of IL10 (rs1800871), IL2 (rs2069763 and rs2069762), IL13 (rs6596090 and rs20541), and IL4R (rs7205663 and rs1805010) were genetically analyzed. To analyze the combined effect of soy intake and genetic polymorphisms, a low-intake group and high-intake group of each type of soy were categorized based on the intake level of the control group. Interactions between soy products and these genetic variants were analyzed by a likelihood ratio test, in which a multiplicative interaction term was added to the logistic regression model.

RESULTS

A higher intake of nonfermented soy products was associated with a reduced cancer risk (odds ratio [OR], 0.62; 95% confidence interval [CI], 0.43 to 0.90), and the reduced risk was only apparent in males (OR, 0.44; 95% CI, 0.27 to 0.71). None of the IL genetic polymorphisms examined were independently associated with gastric cancer risk. Individuals with a minor allele of IL2 rs2069762 and a higher intake of nonfermented soy food had a decreased risk of gastric cancer (OR, 0.46; 95% CI, 0.31 to 0.68) compared to those with a lower intake (pinteraction=0.039).

CONCLUSION

Based on the genetic characteristics of the studied individuals, the interaction between IL2 rs2069762 and nonfermented soy intake may modify the risk of gastric cancer.

No genetic relationship between TLR2 rs4696480, rs3804100, and rs3804099 gene polymorphisms and female breast cancer in Saudi populations

Breast cancer (BC) is the most common cause of cancer-related deaths among women in the Kingdom of Saudi Arabia. An association between the dysregulation of innate immunity, primarily the deregulation of Toll-like receptors (TLRs), and BC development was described a long time ago. Several studies have reported that BC risk factors appear to be related to the interaction between certain genes and exposure to various environmental factors. Here, we investigated the potential correlation of three TLR2 single-nucleotide polymorphisms (SNPs; rs3804100, rs4696480, and rs3804099) with the development of BC in female patients from Saudi Arabia. We collected 126 blood samples from women with BC and 146 blood samples from healthy women without any clinical signs of BC. The genotypic frequencies of TLR2 polymorphisms were assayed. Our results showed that the genotypic and allelic frequencies of TLR2 did not differ significantly between BC patients and healthy controls. However, the distributions of rs3804100 (1350 T/C) genotypes in BC groups were 1%, 19%, and 80% for CC, CT, and TT, respectively. In the control group, the rs3804100 (1350 T/C) genotype distributions were 3%, 18%, and 79% for CC, CT, and TT, respectively. The SNP rs3804100 homozygous “TT” genotype was not associated with the risk of developing BC in the BC patients compared with controls (odds ratio [OR], 4.5; confidence interval [CI], 0.49–41.02; P=0.145). The TLR2 rs4696480 AA genotype was observed in 23% of BC patients compared to 18% of control individuals, the AT genotype was seen in 40% of BC patients and 46% of control individuals, and the TT genotype was observed in 37% of BC patients and 36% of normal controls. Our results did not show any difference in genotypic frequency between BC patients and normal controls for the TLR2 rs3804099 SNP; however, the (C) phenotypic frequency was 49% in BC patients and 53% in controls. The (T) phenotypic frequency was 51% and 47% in BC patients and normal patients, respectively. These findings indicate that there is no association between the TLR2 polymorphisms tested and BC susceptibility in the female population from the Kingdom of Saudi Arabia. We suggest using other TLR2 SNPs to investigate the possible relationship between innate immunity deregulation by disruption of TLR2 and potential BC development.

Toll-like receptor 4 as a predictor of clinical outcomes of estrogen receptor-negative breast cancer in Saudi women

The aim of this study was to investigate the association of the common polymorphisms of Toll-like receptor 4 (TLR-4) with breast cancer development in the Saudi Arabian population. Four TLR-4 polymorphisms (rs2770150, rs10759931, rs10759932, and rs4986790) were studied using 127 breast cancer patients and 117 controls. Relative expression of TLR-4 protein in the breast tumor and the matched normal breast tissues was determined in a large cohort of 70 clinical breast samples in a tissue micro-array format by immunohistochemistry using a specific anti-TLR-4 antibody. Our results demonstrated an increase in TLR-4 expression in estrogen receptor (ER)−, postmenopausal breast cancer patients compared to normal. We also demonstrated that the G allele of single-nucleotide polymorphism rs10759931 was found to be significantly higher in frequency among patients (36.3%) compared to the control group (26.7%), suggesting that this polymorphism is strongly associated with the development of breast cancer in this ethnic population. In addition, the TLR-4 polymorphism rs2770150 was shown to be highly correlated with breast cancer in patients over 48 years of age. The TLR-4 polymorphism rs4986790 was also found to be associated with this malignancy in the ER− patient groups. Our results suggested firstly that the variation in TLR-4 gene expression may influence breast cancer development and secondly a closely linked association between TLR-4 gene polymorphism and ER status. Our study provides support for a better understanding of the implication of TLR-4 polymorphism in breast tumorigenesis and for its eventual use as a cancer biomarker.

Inhibition of CCAR1, a Coactivator of β-Catenin, Suppresses the Proliferation and Migration of Gastric Cancer Cells

The aberrant activation of Wnt signaling has been implicated in a variety of human cancers, including gastric cancer. Given the current hypothesis that cancer arises from cancer stem cells (CSCs), targeting the critical signaling pathways that support CSC self-renewal appears to be a useful approach for cancer therapy. Cell cycle and apoptosis regulator 1 (CCAR1) is a transcriptional coactivator which has been shown to be a component of Wnt/β-catenin signaling, and which plays an important role in transcriptional regulation by β-catenin. However, the function and clinical significance of CCAR1 in gastric cancer have not been elucidated. Here, we show that elevated CCAR1 nuclear expression correlates with the occurrence of gastric cancer. In addition, RNAi-mediated CCAR1 reduction not only suppressed the cell growth and increased apoptosis in AGS and MKN28 cells, but also reduced the migration and invasion ability of these cells. Furthermore, an in vivo xenograft assay revealed that the expression level of CCAR1 was critical for tumorigenesis. Our data demonstrates that CCAR1 contributes to carcinogenesis in gastric cancer and is required for the survival of gastric cancer cells. Moreover, CCAR1 may serve as a diagnostic marker and a potential therapeutic target.

Correlation between the germline methylation status in ERβ promoter and the risk in prostate cancer: a prospective study

Familial aggregation of cancer may reflect an overall contribution of inherited genes or a shared mechanism for the manipulation of gene function. DNA methylation in the promoter regions is considered to be a mechanism through which tumor suppressor genes are inhibited, which will lead to tumorigenesis and tumor progression. To evaluate the association between the methylation status in the promoter of estrogen receptor (ER) β,possibly a tumor suppressor gene specific for prostate cancer, and the risk in prostate cancer in a Chinese population, a case-control study that included 56 sporadic prostate cancer cases and 60 healthy controls was conducted. Genomic DNA was extracted from peripheral blood of all the subjects for analyzing the methylation status of the ERβ promoter by methylation-specific PCR, which was verified by bisulfite genomic sequencing PCR. A significant difference was observed in the methylation frequencies of the ERβ promoter between cancer patients (12/56, 21.4%) and healthy controls (5/60, 8.3%). Prostate cancer (PC-3 and DU-145) and prostatic epithelial (RWPE-1) cell lines were treated with various concentrations of the methyltransferase inhibitor 5-Aza-2'-dC. Expression of ERβ was detected at both transcriptional and translational levels. As a result, both mRNA and protein of ERβ were elevated following treatment with increasing concentrations of the demethylating agent. Taken together, our results support the conclusion that abnormal methylation of the ERβ promoter may increase genetic susceptibility to prostate cancer.

Clinical Characteristics and Outcomes of Gastric Cancer Patients Aged over 80 Years: A Retrospective Case-Control Study

BACKGROUND AND AIMS

The average human life expectancy is increasing worldwide, thus the proportion of elderly gastric cancer patients is also increasing. In this case-control study, we investigated the clinical and oncologic outcomes of gastric cancer in patients over 80 years old.

METHODS

From January 2004 to December 2010, 291 patients aged over 80 years old (case group) were diagnosed and treated with gastric cancer at Asan Medical Center, Seoul, Korea. From the same period, 291 patients aged 18 to 80 years old were selected as the control group. The clinical findings and clinical outcomes of gastric cancer were retrospectively reviewed and compared between the two groups.

RESULTS

There were significant differences in the overall 5-year survival rate between the case and control groups (30.9% vs. 73.8%, respectively; P<0.001). In patients who received the curative treatment, overall 3- and 5-year survival rates showed 74.3% and 57.9% in case group and 91.6% and 86.5% in the control group. When analysis was confined to resectable elderly patients with a favorable performance, the curative resection group showed significantly better overall 3- and 5-year survival rates than the conservative treatment group (73.7% and 58.8% vs. 29.8% and 0%, respectively).

CONCLUSIONS

Although elderly gastric cancer patients show an advanced stage at diagnosis and poor prognosis compared with non-elderly patients, elderly patients with good performance could benefit from curative resection. Thus, the clinical decision whether to undergo curative resection or conservative management should be made on an individualized basis.

miR-27b inhibits gastric cancer metastasis by targeting NR2F2

Increasing attention is focused on the down-regulation of miRNAs in cancer process. Nuclear receptor subfamily 2 (NR2F2, also known as COUP-TFII) is involved in the development of many types of cancers, but its role in gastric cancer remains elusive. In this experiment, oncomine and Kaplan-meier database revealed that NR2F2 was up-regulated in gastric cancer and that the high NR2F2 expression contributed to poor survival. MicroRNA-27b was targeted and down-regulated by NR2F2 in human gastric cancer tissues and cells. The ectopic expression of miR-27b inhibited gastric cancer cell proliferation and tumor growth in vitro and in vivo. Assays suggested that the overexpression of miR-27b could promote MGC-803 cells’ migration and invasion and retard their metastasis to the liver. In addition, down-regulation of miR-27b enhanced GES-1 cells’ proliferation and metastasis in vitro. These findings reveal that miR-27b is a tumor suppressor in gastric cancer and a biomarker for improving patients’ survival.

Tissue transglutaminase-1 promotes stemness and chemoresistance in gastric cancer cells by regulating Wnt/β-catenin signaling

Gastric cancer is a common malignancy, and is one of the most frequent causes of cancer deaths worldwide. Recently, members of the transglutaminases (TGM) family, especially TGM2, have been implicated in the progression and drug resistance of cancers, but the function of TGM1 in cancer development has been largely overlooked. In this study, we demonstrate the roles of TGM1 in development of gastric cancer. We found that expression levels of TGM1 were upregulated in both gastric cancer tissues and cultured gastric cancer cells, and that TGM1 expression levels were correlated with patient survival. In cultured gastric cancer cells, loss of TGM1 expression inhibited cell proliferation and promoted apoptosis, as well increased gastric cancer cell sensitivity to chemotherapeutic drugs and reducing stemness. These results strongly supported the participation of TGM1 in the regulation of gastric cancer development. In addition, we found evidence that the mechanism of action of TGM1 in regulating gastric cancer cell might involve the Wnt signaling pathway, as loss of TGM1 expression in gastric cancer cells led to a significant suppression of Wnt signaling activities.

Association between polymorphisms in segregation genes BUB1B and TTK and gastric cancer risk

BACKGROUND

Malignant transformation of normal gastric cells is a complex and multistep process, resulting in development of heterogeneous tumours. Susceptible genetic background, accumulation of genetic changes, and environmental factors play an important role in gastric carcinogenesis. Single nucleotide polymorphisms (SNPs) in mitotic segregation genes could be responsible for inducing the slow process of accumulation of genetic changes, leading to genome instability.

PATIENTS AND METHODS

We performed a case-control study of polymorphisms in mitotic kinases TTK rs151658 and BUB1B rs1031963 and rs1801376 to assess their effects on gastric cancer risk. We examined the TTK abundance in gastric cancer tissues using immunoblot analysis.

RESULTS

C/G genotype of rs151658 was more frequent in patients with diffuse type of gastric cancer and G/G genotype was more common in intestinal types of gastric cancers (p = 0.049). Polymorphic genotype A/A of rs1801376 was associated with higher risk for developing diffuse type of gastric cancer in female population (p = 0.007), whereas A/A frequencies were increased in male patients with subserosa tumour cell infiltration (p = 0.009). T/T genotype of rs1031963 was associated with well differentiated tumours (p = 0.035). TT+CT genotypes of rs1031963 and GG+AG genotypes of rs1801376 were significantly associated with gastric cancer risk (dominant model; OR = 2,929, 95% CI: 1.281-6.700; p = 0.017 and dominant model; OR = 0,364, 95% CI: 0.192-0.691; p = 0.003 respectively).

CONCLUSIONS

Our results suggest that polymorphisms in mitotic kinases TTK and BUB1B may contribute to gastric tumorigenesis and risk of tumour development. Further investigations on large populations and populations of different ethnicity are needed to determine their clinical utility.

Decreased expression of the long noncoding RNA LINC00261 indicate poor prognosis in gastric cancer and suppress gastric cancer metastasis by affecting the epithelial-mesenchymal transition

BACKGROUND

Recent evidence indicates that long noncoding RNAs (lncRNAs) play pivotal roles in the regulation of cellular processes and are found to be dysregulated in a variety of cancers. LINC00261 is an lncRNA that is aberrantly expressed in gastric cancer (GC). The clinical role of LINC00261 in GC and molecular mechanisms remains to be found.

METHODS

Real-time polymerase chain reaction (PCR) was used to examine LINC00261 expression in GC cell lines/tissues compared with normal epithelial cells/adjacent non-tumorous tissues. Gain and loss of function approaches were used to investigate the biological role of LINC00261 in GC cells. The effects of LINC00261 on cell viability were evaluated by MTT and colony formation assays. Wound healing assay, cell migration and invasion assays, and nude mice were used to examine the effects of LINC00261 on tumor cell metastasis in vitro and in vivo. Protein levels of LINC00261 targets were determined by western blot and immunohistochemistry.

RESULTS

LINC00261 was downregulated in GC cell lines and cancerous tissues, as compared with normal gastric epithelial cells and adjacent noncancerous tissue samples. Low LINC00261 expression was correlated with deeper tumor invasion (P < 0.001), higher tumor stage (P = 0.013), and lymphatic metastasis (P = 0.006). Univariate and multivariate analyses indicated that low LINC00261 expression predicted poor prognosis. Ectopic expression of LINC00261 impaired cell migration and invasion, leading to the inhibition of metastasis in vitro and in vivo. Knockdown of LINC00261 expression promoted cell migration and invasion in vitro. Overexpression of LINC00261 was found to play a key role in epithelial-mesenchymal transition (EMT) through the regulation of E-cadherin, N-cadherin, and Vimentin expression.

CONCLUSIONS

Low expression of the lncRNA LINC00261 occurs in GC and is associated with poor prognosis. LINC00261 suppresses GC metastasis by regulating EMT. Thus, LINC00261 plays an important role in the progression and metastasis of GC.

Low Expression of the bcl2 Gene in Gastric Adenocarcinomas in Mazandaran Province of Iran

BACKGROUND

Gastric cancer accounts for about 8% of the total cancer cases and 10% of total cancer deaths worldwide. It is the second lethal cancer after esophageal cancer and is considered the fourth most common cancer in north and northwest Iran. The bcl2 family has a key role in the regulation of apoptosis and change in its expression can contribute to cancer. This study initially scheduled to determine the expression of bcl2 gene in tissue samples of adenocarcinoma cancer patients.

MATERIALS AND METHODS

A total of 10 samples of gastric adenocarcinoma and 10 of normal tissues from Sari hospital were selected and after DNA extraction from tissues, bcl2 gene expression assayed by real-time PCR.

RESULTS

Our results demonstrated higher expression of the bcl2 gene in control compared with cancer and marginal cancer tissues.

CONCLUSIONS

On one hand BCL2 plays an important role as an oncogene to inhibit apoptosis; on the other hand, it can initiate cell cycle arrest at G0 stage. Our observed association between its expression and patient survival is quite conflicting and may be tissue-specific. The data suggest expression both tumoural and non-tumoral(marginal) groups have lowered expression than controls (P>0.05). Due to the low number of samples we could not examine the relationship with clinicopathological features. However, bcl-2 expression may be important for prognostic outcome or a useful target for therapeutic intervention.