Pathogenesis Of Gastric Carcinoma Research Articles

Role of Helicobacter pylori in Gastric Carcinoma: A Review.

Gastric cancer (GC) is one of the leading causes of cancer-related deaths globally. Gastritis caused byHelicobacter pylori (H. pylori)is a potent cause of gastrointestinal malignancies. The majority of all humans on the planet haveH. pylori invasionin their stomachs, yet only a few diseased people develop GC. The human gastrointestinal system contains a broad population of microorganisms in addition toH. pylori.H. pyloriheterogeneity has been studied because not allH. pyloridiseases result in cancer. Individuals in the adult age group account for the bulk of gastric carcinoma cases.H. pylorihas various strains, which is beneficial for its survival in host cell epithelium for a longer duration of time. Along withH. pylori, oral microbes have a major role in the pathogenicity of gastric carcinoma. The complex ecology of oral microbiota helps to defend against infections, preserve homeostasis, and regulate the immune system. In contrast, oral microbiota is involved in various mechanisms like anti-apoptotic activity, suppression of the immune system of the host, and initiation of chronic inflammation. These oral microbes are also responsible for the development of mutations. Interactions between the host immune system and bacteria promote the progression of cancer. For this review, various research articles were studied, and information was collected using databases like PubMed and Google Scholar. This review emphasizes on the role ofH. pyloriin gastric carcinoma, its pathogenesis,the role of various virulence factors and risk factors related to it, the role of oral microbiota in gastric carcinoma pathogenesis, diagnostic modalities, treatment options, and preventive measures for gastric carcinoma.

Molecular characterization and potential therapeutic roles of miR125a in HER-2 positive gastric cancer.

miR-125a-3p could have a role in gastric cancer by targeting HER2. This study aimed to investigate the expression pattern of miR-125a-3p, identify the expression level of its target gene in gastric carcinoma, and test its effect in HER-2 positive gastric carcinoma cells. The levels of miR-125a-3p in both cancer and noncancer tissues were measured by using Quantitative real-time polymerase chain in 70 gastric carcinomas. Immunohistochemical study was used to measure the expression of HER2 protein in these carcinomas. In addition, the level of expression of this miRNA is correlated to different pathological and clinical parameters. The effects of miR-125a-3p alone and in combination with 5-FU (fluorouracil) on the growth of HER2 positive (NUGC4) and HER2 negative (ECC10) gastric carcinoma cells were also analyzed by in vitro studies. Most gastric cancer tissues samples showed downregulation of miR-125a-3p (84%) when compared to their noncancer tissues. Significant correlations of downregulation of miR-125a-3p with cancer recurrence and pathological staging of gastric carcinoma (P = 0. 02 and 0.02, respectively) were noted. HER2 protein expression correlated significantly and inversely with miR-125a-3p expression (P < 0.05). A reduction in cell growth rate was noted significantly in miR-125a-3p transfected gastric carcinoma cells when 5-FU was added to them in comparison to other control cells (P < 0.01). When both gastric carcinoma cell lines were transfected with miR-125a-3p, a significantly higher growth inhibition percentage in HER2 positive (NUGC4) cell line was seen in comparison to the HER2 negative (ECC10) cells (P < 0.01). miR-125a-3p plays a significant role in the pathogenesis of gastric carcinoma. Therapeutic transfection of miR-125a-3p in HER2 positive gastric cancer cells resulted in reduced cell proliferation and potentiate the effect of 5-FU.

Knockdown of miR-125b-5p inhibits the proliferation and invasion of gastric carcinoma cells by targeting RYBP.

Gastric carcinoma, one of the most aggressive and lethal human malignancies, is associated with poor prognosis despite progress in therapeutic strategies. This study examined the potential function and mechanism of action of microRNA-125b-5p (miR-125b-5p) in the pathogenesis of gastric carcinoma. We recognized that miR-125b-5p was elevated in gastric carcinoma, and its decreased expression was associated with a better prognosis. Loss-of-function assays showed that miR-125b-5p suppression inhibited the proliferative and invasive abilities of gastric cancer cells. Furthermore, RING1 and YY1-binding protein (RYBP) was found to be target gene for miR-125b-5p action; miR-125b-5p negatively regulates RYBP expression. According to the results of rescue experiments, RYBP downregulation partially counteracted the miR-125b-5p silence-mediated inhibitory function in gastric cancer progression. Collectively, these data elucidated the molecular mechanisms of the miR-125b-5p/RYBP axis in gastric cancer invasion and growth.

Elevated Expression of DNA Methyltransferases and Enhancer of Zeste Homolog 2 in Helicobacter pylori - Gastritis and Gastric Carcinoma

Aim: The aim of this study was to study the role of key epigenetic regulators pertaining to DNA methylation and histone-modification systems in Helicobacter pylori (HP)-associated gastritis and gastric carcinogenesis. Methods: The expression of DNA methyltransferase (DNMT-1, 3A, and 3B) and the catalytic subunit of polycomb repressive complex-2 (enhancer of zeste homolog 2 [EZH2]) in gastric carcinomas (n = 104), mucosa adjacent to carcinoma (n = 104), HP-associated gastritis (n = 95), and histologically normal mucosa (n = 31) was assessed by immunohistochemistry and qRT-PCR. Results: The expression of all 3 DNMTs and EZH2 was significantly higher in HP-associated gastritis and carcinoma cases than in those with adjacent and normal mucosa. The expression of DNMT-1 and 3B was maximum in HP-associated gastritis. DNMT-3A showed higher expression in carcinoma-adjacent mucosa than in normal mucosa. Interestingly, the expression of EZH2 was higher in cases of HP-associated gastritis with metaplasia than in those without metaplasia and also in cases of intestinal type of adenocarcinoma. Significant positive correlation of EZH2 was identified with DNMT-1, DNMT-3A, and DNMT-3B. However, none of these markers was associated with survival outcome. Conclusion: This study establishes an important role of the key epigenetic regulators in the pathogenesis of both HP-associated gastritis and gastric carcinoma. Higher expression of all the epigenetic markers in the gastritis and their persistence in the carcinoma point toward their implications in HP-driven gastric carcinogenesis. Further, an inter-relation between the 2 arms of epigenetics, namely, DNA methylation and histone-modification in the pathogenesis of gastric carcinoma, is also documented. Given the reversibility of epigenetic phenomenon, these molecules may be of important therapeutic use.

The Dysfunctional Immune System in Common Variable Immunodeficiency Increases the Susceptibility to Gastric Cancer.

Gastric carcinoma (GC) represents the most common cause of death in patients with common variable immunodeficiency (CVID). However, a limited number of cases have been characterised so far. In this study, we analysed the clinical features, bacterial/viral infections, detailed morphology and immune microenvironment of nine CVID patients with GC. The study of the immune microenvironment included automated digital counts of CD20+, CD4+, CD8+, FOXP3+, GATA3+ and CD138+ immune cells, as well as the evaluation of PD-L1 expression. Twenty-one GCs from non-CVID patients were used as a control group. GC in CVID patients was diagnosed mostly at early-stage (n = 6/9; 66.7%) and at younger age (median-age: 43y), when compared to non-CVID patients (p < 0.001). GC pathogenesis was closely related to Helicobacter pylori infection (n = 8/9; 88.9%), but not to Epstein-Barr virus (0.0%) or cytomegalovirus infection (0.0%). Non-neoplastic mucosa (non-NM) in CVID-patients displayed prominent lymphocytic gastritis (100%) and a dysfunctional immune microenvironment, characterised by higher rates of CD4+/CD8+/Foxp3+/GATA3+/PD-L1+ immune cells and the expected paucity of CD20+ B-lymphocytes and CD138+ plasma cells, when compared to non-CVID patients (p < 0.05). Changes in the immune microenvironment between non-NM and GC were not equivalent in CVID and non-CVID patients, reflecting the relevance of immune dysfunction for gastric carcinogenesis and GC progression in the CVID population.

RN181 is a tumour suppressor in gastric cancer by regulation of the ERK/MAPK-cyclin D1/CDK4 pathway.

RN181, a RING finger domain‐containing protein, is an E3 ubiquitin ligase. However, its biological function and clinical significance in cancer biology are obscure. Here, we report that RN181 expression is significantly down‐regulated in 165 tumour tissues of gastric carcinoma (GC) versus adjacent non‐tumour tissues, and inversely associated with tumour differentiation, tumour size, clinical stage, and patient's overall survival. Alterations of RN181 expression in GC cells by retrovirus‐transduced up‐regulation and down‐regulation demonstrated that RN181 functions as a tumour suppressor to inhibit growth of GC in both in vitro culture and in vivo animal models by decreasing tumour cell proliferation and increasing tumour cell apoptosis. Cell cycle analysis revealed that RN181 controls the cell cycle transition from G1 to S phase. Mechanistic studies demonstrated that RN181 inhibits ERK/MAPK signalling, thereby regulating the activity of cyclin D1–CDK4, and consequently controlling progression in the cell cycle from G1 to S phase. Restoring CDK4 in GC cells rescued the inhibitory phenotype produced by RN181 in vitro and in vivo, suggesting a dominant role of CDK4 in control of the tumour growth by RN181. Importantly, RN181 expression is inversely correlated with the expression of cyclin D1 and CDK4 in GC clinical samples, substantiating the role of the RN181–cyclin D1/CDK4 pathway in control of the tumour growth of GC. Our results provide new insights into the pathogenesis and development of GC and rationale for developing novel intervention strategies against GC by disruption of ERK/MAPK–cyclin D1/CDK4 signalling. In addition, RN181 may serve as a novel biomarker for predicting clinical outcome of GC. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

EBV Positive Gastric Carcinomas and Their Clinicopathological Characteristics.

BACKGROUND:The understanding of the etiopathogenesis of gastric carcinoma (GC) can be a base for development of new therapeutic methods to reduce mortality and to increase survival in patients with GC. The percentage of Epstein - Barr virus (EBV) positive gastric carcinomas is uncertain, and the etiologic importance of EBV in the pathogenesis of GC has still not been elucidated.AIM:This study aimed to determine the percentage of EBV associated GC as well as to determine their clinicopathological characteristics.MATERIAL AND METHODS:The study included 80 patients with GC who were analysed for ethnicity, local growth of a tumour (T status), the presence of nodal metastases (N), the presence of distant metastases (M), stage of the disease and degree of carcinoma differentiation. For detection of EBV, immunostainings were performed on tumour tissue and the peripheral non-tumour gastric mucosa.RESULTS:Positive immunostaining with an antibody against EBV was found in 19 (23.75%) of the 80 patients with gastric carcinomas. EBV immunostainings were significantly different in patients with or without metastasis and between patients of Macedonian and Albanian ethnicity (p < 0.0001, p < 0.009, respectively). EBV immunoexpression was significantly associated with the presence of distant metastases and with patients of Albanian ethnicity.CONCLUSION:Association of EBV immunostainings with distant metastasis in patients with GC suggests the influence of EBV infection on the progression of gastric carcinoma. Due to scarce and doubtful literature data on EBV associated GC, further studies are necessary to determine the role of EBV regarding aetiology, treatment and prognosis in patients with EBV associated gastric carcinoma.

Helicobacter pylori infection promotes Aquaporin 3 expression via the ROS-HIF-1α-AQP3-ROS loop in stomach mucosa: a potential novel mechanism for cancer pathogenesis.

Helicobacter pylori (H. pylori) is the major stomach carcinogen, but the molecular mechanism responsible for the pathogenesis of cancer development mediated by H. pylori infection is still unclear. Aquaporin 3 (AQP3), overexpressed in gastric carcinoma, has a crucial role in gastric carcinogenesis and progression. However, the triggers and precise regulations for AQP3 upregulation during gastric carcinogens also remain unknown. Here we report that H. pylori infection-mediated carcinogenesis may be mechanistically depended on the upregulation of AQP3 expression via reactive oxygen species (ROS) pathway activation in the stomach. The retrospective analyses of clinical samples from patients with gastric carcinoma and other different stages of gastric diseases indicated that AQP3 expression was positively associated with gastric mucosal disease progression and H. pylori infection status as well. Furthermore, H. pylori infection significantly upregulated AQP3 and HIF-1α expression and increased ROS amount in human gastric epithelial AGS and GES-1 cells. Blockage of ROS with inhibitors, NAC and DPI, markedly decreased the expression of AQP3 and HIF-1α in both AGS and GES-1 cells simultaneously. Furthermore, the increased AQP3 in cells was mechanistically due to the transcriptional regulation by HIF-1α. In addition, H. pylori infection exerted production of proinflammatory cytokines IL-6, IL-8, and TNF depending on AQP3 level. Importantly, these in vitro novel findings were further investigated in vivo in a mouse H. pylori infectious model. Our current studies identify the mechanistic link between H. pylori infection and AQP3 upregulation in the pathogenesis of gastric carcinoma, which involves the activation of the ROS-HIF-1α axis and the exacerbated ROS-HIF-1α-AQP3-ROS loop.

The Pathogenesis of Gastric Carcinoma

The Pathogenesis of Gastric Carcinoma

Interaction of Epstein-Barr virus genes with human gastric carcinoma transcriptome.

Gastric carcinoma (GC) is a leading cause of mortality. 10% of GC cases are related with EBV (Epstein-Barr virus) infection. The detailed mechanistic roles EBV genes play and especially the interaction between the viral genes and human genes in GC remain unclear. In this study, raw fastq data from 285 GC samples were downloaded from TCGA (The Cancer Genome Atlas), including 25 EBV positive (EBV+) GC samples and 260 EBV negative (EBV−) GC samples. RNA-seq based expression data were generated for both human genes (among all the samples) and for the EBV genes (among the 25 EBV+ samples). Bioinformatics analyses were performed to identify differentially expressed (DEx) human genes and DEx KEGG pathways in EBV+ vs. EBV− samples and co-expressed human gene modules and hub genes among the DEx genes. Within the EBV+ samples, analyses were conducted to find correlation between EBV gene expression and the human gene expression modules, between EBV gene expression and the human hub genes, and between EBV gene expression and the DEx human pathways. EBV genes LMP-1, BALF1 and BALF2 were found to have significant correlation with human hub genes, CNTD2 and VANGL2. EBV genes BALF4 and BALF5 were found to correlate with human pathways, including Jak-STAT signaling and Phosphatidylinositol Signaling System. Our study has revealed the coordinated expression patterns between EBV and human GC transcriptome and identified several key EBV genes that may play an important role in EBV+ GC pathogenesis through their interactions with human genes and pathways.

Prevalence of H. pylori in gastric biopsy specimen in the southeastern region of Turkey.

Helicobacter pylori is a Gram-negative, microaerophilic bacterium that colonizes human gastric mucosa. Gastric ulcer, duodenal ulcer, chronic atrophic gastritis, mucosa-associated lymphoid tissue lymphoma, and stomach adenocarcinoma are associated with H. pylori as the etiological agent. Cytotoxin-associated gene A (cagA), which is one of the most important virulence factors of H. pylori, encodes a 120-145 kDa protein. The prevalence of cagA genes shows differences in H. pylori infections based on geographical area, and cagA-positive H. pylori strains play an important role in pathogenesis of gastric carcinoma. The aim of this study was to detect the prevalence of cagA and vacA genes in H. pylori isolates in adult patient groups in the southeastern region of Turkey. The presence of H. pylori was investigated in gastric biopsy specimens using the culture method, and polymerase chain reaction (PCR) analysis was performed to detect the presence of the cagA and vacA s1 genes. H. pylori was detected in 65% (84/129) of patients who had gastrointestinal complaints. The number of vacA s1 and cagA genes of isolates were 44 (74.5%) and 31 (52.5%), respectively. H. pylori infection in southeastern region of Turkey with are comparable to those in developed countries. Patients with cagA- and vacA-positive H. pylori have a higher risk of severe inflammation and atrophy and should therefore be monitored for the development of gastric cancer.

Helicobacter pylori virulence factors in development of gastric carcinoma.

Helicobacter pylori plays a vital role in the pathogenesis of gastric carcinoma. However, only a relatively small proportion of individuals infected with H. pylori develop gastric carcinoma. Differences in the incidence of gastric carcinoma among infected individuals can be explained, at least partly, by the different genotypes of H. pylori virulence factors. Thus far, many virulence factors of H. pylori, such as Cag PAI, VacA, OMPs and DupA, have been reported to be involved in the development of gastric cancer. The risk of developing gastric cancer during H. pylori infection is affected by specific host-microbe interactions that are independent of H. pylori virulence factors. In this review, we discuss virulence factors of H. pylori and their role in the development of gastric carcinoma that will provide further understanding of the biological interactions of H. pylori with the host.

Corrigendum to “Optimization and Corroboration of the Regulatory Pathway of p42.3 Protein in the Pathogenesis of Gastric Carcinoma”

In the article “Optimization and Corroboration of the Regulatory Pathway of p42.3 Protein in the Pathogenesis of Gastric Carcinoma” [1], there was an error in the author information. The affiliations for the authors were incorrectly listed. The correct author line and affiliations are shown above.

Expression of erythropoietin producing human hepatocellular receptor A2 and CD133 in gastric carcinoma and their correlation with development of gastric cancer

Objective To analyze the expression of erythropoietin producing human hepatocellular receptor A2(EphA2)and CD133 in gastric carcinoma and their relationship with clinicopathological features and the prognosis of gastric carcinoma. Methods Envision immunohistochemical method was used to assess the expression of EphA2 and CD133 in 82 cases of human gastric carcinoma tissues and non-cancerous adjacent gastric tissues. Results The expression rate of EphA2 in gastric carcinoma tissues was higher than that in non-cancerous adjacent gastric tissues(86.59% vs.20.73%,P< 0.01). The expression rate of CD133 in gastric carcinoma tissues was higher than that in non-cancerous adjacent gastric tissues(67.07% vs.10.98%,P< 0.01).The expression of Eph A2 was related to TNM stage and lymph node metastasis of gastric carcinoma(P< 0.05). There was a close correlation between the expression of CD133 and histological grade, TNM stage and lymph node metastasis(P<0.05). Conclusion The overexpression of EphA2 and CD133 may play certain roles in the pathogenesis of gastric carcinoma. Key words: Gastric carcinoma; Eerythropoietin producing human hepatocellular receptor A2; CD133; Immunohistochemical method

Optimization and Corroboration of the Regulatory Pathway of p42.3 Protein in the Pathogenesis of Gastric Carcinoma.

Aims. To optimize and verify the regulatory pathway of p42.3 in the pathogenesis of gastric carcinoma (GC) by intelligent algorithm. Methods. Bioinformatics methods were used to analyze the features of structural domain in p42.3 protein. Proteins with the same domains and similar functions to p42.3 were screened out for reference. The possible regulatory pathway of p42.3 was established by integrating the acting pathways of these proteins. Then, the similarity between the reference proteins and p42.3 protein was figured out by multiparameter weighted summation method. The calculation result was taken as the prior probability of the initial node in Bayesian network. Besides, the probability of occurrence in different pathways was calculated by conditional probability formula, and the one with the maximum probability was regarded as the most possible pathway of p42.3. Finally, molecular biological experiments were conducted to prove it. Results. In Bayesian network of p42.3, probability of the acting pathway “S100A11→RAGE→P38→MAPK→Microtubule-associated protein→Spindle protein→Centromere protein→Cell proliferation” was the biggest, and it was also validated by biological experiments. Conclusions. The possibly important role of p42.3 in the occurrence of gastric carcinoma was verified by theoretical analysis and preliminary test, helping in studying the relationship between p42.3 and gastric carcinoma.

The Role of PI3K/Akt/mTOR Signaling in Gastric Carcinoma.

The phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is one of the key signaling pathways induced by various receptor-tyrosine kinases. Accumulating evidence shows that this pathway is an important promoter of cell growth, metabolism, survival, metastasis, and resistance to chemotherapy. Genetic alterations in the PI3K/Akt/mTOR pathway in gastric carcinoma have often been demonstrated. Many kinds of molecular targeting therapies are currently undergoing clinical testing in patients with solid tumors. However, with the exception of the ErbB2-targeting antibody, targeting agents, including PI3K/Akt/mTOR inhibitors, have not been approved for treatment of patients with gastric carcinoma. This review summarizes the current knowledge on PI3K/Akt/mTOR signaling in the pathogenesis of gastric carcinoma and the possible therapeutic targets for gastric carcinoma. Improved knowledge of the PI3K/Akt/mTOR pathway in gastric carcinoma will be useful in understanding the mechanisms of tumor development and for identifying ideal targets of anticancer therapy for gastric carcinoma.

Chromosome 8q as the most frequent target for amplification in early gastric carcinoma.

Early gastric carcinoma (GC) is considered to be a curable cancer, as it progresses to the advanced stage following varying durations. Understanding the early stage of GC may provide an insight into its pathogenesis and contribute to reducing the mortality rate of this disease. To investigate the genomic aberrations associated with 22 cases of early GC, high-density microarray comparative genomic hybridization was performed in the present study. The most notable finding was copy number gains (log2 ratio >0.25) on the long arm of chromosome 8, which occurred in 77.3% (17/22) of GC cases, and the delineated minimal common region was 8q22.1-q24.3. More specifically, two amplified (log2 ratio >1) loci in the 8q22.1-q24.3 region were detected in 18.2% (4/22) of GC cases. The first loci covered a region of 102.4–107.9 kb, mapping on 8q22.3-q23.1, and comprised the transcription factor CP2-like 3 gene. The second loci, spanning 128.7–145.7 kb on 8q24.21-q24.3, comprised the representative oncogene of myelocytomatosis. Furthermore, the following possible target genes that were not previously considered to play a pathogenic role in GC were identified: Plasmacytoma variant translocation 1, cysteine/histidine rich 1, kinesin family member C2, forkhead box H1, protein phosphatase 1 regulatory subunit 16A, glutamic-pyruvate transaminase, LOC113655 and RecQ protein-like 4. In the present study, previous findings showing that 8q mutations accumulate early during the multistage pathogenesis of GC were confirmed and expanded upon. The confirmation of previously reported 8q gains and the identification of novel target genes at 8q22.1-q24.3 amplified chromosomal sites should aid in improving our understanding of the molecular mechanisms underlying the tumorigenesis of early GC.

Role of the tumor microenvironment in the pathogenesis of gastric carcinoma

Gastric carcinoma (GC) is the 4(th) most prevalent cancer and has the 2(nd) highest cancer-related mortality rate worldwide. Despite the incidence of GC has decreased over the past few decades, it is still a serious health problem. Chronic inflammatory status of the stomach, caused by the infection of Helicobacter pylori (H. pylori) and through the production of inflammatory mediators within the parenchyma is suspected to play an important role in the initiation and progression of GC. In this review, the correlation between chronic inflammation and H. pylori infection as an important factor for the development of GC will be discussed. Major components, including tumor-associated macrophages, lymphocytes, cancer-associated fibroblasts, angiogenic factors, cytokines, and chemokines of GC microenvironment and their mechanism of action on signaling pathways will also be discussed. Increasing our understanding of how the components of the tumor microenvironment interact with GC cells and the signaling pathways involved could help identify new therapeutic and chemopreventive targets.

Immunohistochemical expression and significance of NM23 suppressor protein in primary gastric adenocarcinoma

NM 23 protein was originally identified as a metastasis suppressor protein. The expression of NM23 has been correlated with tumour metastatic potential in various human carcinoma, mostly in ductal breast and colorectal carcinomas. Evidence for their expression in gastric cancer is rather contradictory, both for protein expression status and prognostic value. This study was done to analyze the immunohistochemical expression of NM23 in gastric carcinoma, and correlation of the degree of staining with clinicopathological parameters was investigated. In a retrospective immunohistochemical study specimens obtained from 56 gastric cancer patients who had undergone gastrectomy with perigastric lymphadenectomy were analysed, in correlation with classical clinical-pathological parameters of tumours, WHO-, Lauren-, Goseki-, and Ming- classification. NM 23 gene expression was compared in gastric adenocarcinoma and tumour-adjacent non-neoplastic gastric mucosa. A semiquantitative immunostaining evaluation (score 0-3) was used, counting the percentage of stained cells. Statistical analysis was performed using Kolmogorov-Smirnov test, and Spearman rank correlation test. The investigated group consisted of 40 males and 16 females (2.5:1) with a mean age of 63 years (range: 48-81 years). The percentage of positive expression of NM23 (score 3) were in 30 (53.5%) specimens in non-neoplastic mucosa in adjacent gastric carcinoma, and negative (score 0-2) in all 56 (100%) specimens of gastric adenocarcinoma. NM23 expression was higher in non-neoplastic mucosa than in adjacent gastric adenocarcinoma tissue (p<0.0001). NM23 protein expression did not correlate with gender (p=0.115), tumour size (p=0.844), tumour grade (p=0.172), lymphovascular invasion (p=0.606), lymph node metastases (p=0.311), Lauren classification (p=0.426), Goseki classification (p=0.458) and Ming classification (p=0.212). Our series did not show a significant correlation between NM23 expression and analysed clinico-pathological variables, but these results suggest that protein NM23 may have a role in gastric carcinoma pathogenesis.

Correlation of CpG methylation status of Runx3 with pathogenesis of gastric carcinoma

To investigate the role of Runx3 gene CpG island methylation in the development of human gastric carcinoma. A total of 150 tumor specimens from patients with gastric carcinoma and 50 normal tissue specimens were selected. Methylation specific PCR (MSP) and pyrosequencing (PS) were used to detect the methylation status of Runx3 gene promoter. Compared to normal tissue samples, a significant increase of CpG island methylation status of Runx3 gene was observed in gastric carcinomas (MSP: 67.3% vs. 40.0%, P = 0.002; PS: 76.0% vs. 30.0%, P < 0.01). Runx3 gene methylation was only related to tumor size (P < 0.05) based on MSP analysis. PS test however showed that the extent of methylation of Runx3 gene was related to the tumor size (P = 0.004), Lauren's classification (P = 0.043), depth of invasion (P < 0.01), lymph node metastasis (P = 0.021) and TNM staging (P = 0.045). Methylation status of Runx3 gene detectable by PS is closely correlated with clinicopathological parameters of gastric carcinoma, including tumor size, Lauren's classification, depth of invasion, lymph node metastasis and TNM staging. PS is more sensitive than MSP in the detection of Runx3 gene methylation, which may serve as an important marker for early diagnosis and treatment of gastric carcinoma.