Loss of RUNX3 expression correlates with differentiation, nodal metastasis, and poor prognosis of gastric cancer.
ABSTRACT RUNX3 is a major growth regulator of gastric epithelial cells that is involved in gastric tumorigenesis in both humans and mice. In this study, we investigated the involvement of RUNX3 in tumor progression, and in the prognosis of human gastric cancer.
We analyzed the extent of RUNX3 protein expression by immunohistochemistry in 95 primary gastric adenocarcinomas, and correlated expression levels with clinicopathological parameters. We examined the effects of pFlag/RUNX3 on cell growth, apoptosis, and caspase-3 expression in AGS and SNU1 gastric cancer cell lines by colony-forming assay, terminal deoxynucleotidyl transferase (TdT)-mediate deoxyuridine triphosphatase (dUTP) nick-end labeling (TUNEL) assay, and Western blot analysis, respectively. The pFlag/RUNX3 effects on AGS invasion and migration potentials were also evaluated.
RUNX3 expression was lost in 37 (39%) cases of gastric cancer. The expression of RUNX3 in diffuse- and mixed-type cancers was less frequent than expression in intestinal-type cancer (P < 0.001 and P = 0.001, respectively). In addition, the loss of RUNX3 expression was associated with lymph node metastasis (P = 0.02), and correlated with poor gastric cancer survival (P = 0.018). The growth of gastric cancer cells was suppressed after pFlag/RUNX3 transfection. The re-expression of RUNX3 resulted in the upregulation of caspase-3 and promoted apoptosis. Furthermore, Re-expression of RUNX3 induced significant inhibitions of AGS cell invasion and migration in vitro.
This work shows that loss of RUNX3 expression is highly associated with lymph node metastasis and poor prognosis of gastric cancer. The re-expression of RUNX3 may induce apoptosis and inhibit the growth as well as invasion/migration of cancer cells. These results indicate that the targeting of the RUNX3 pathway could represent a potential modality for treating gastric cancer.
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ABSTRACT: This study was performed to determine the association between RUNX3 expression and Helicobacter pylori infection in premalignant gastric lesions. We examined 107 patients with gastric epithelial dysplasia who had undergone endoscopic mucosal resection or submucosal dissection. All tissue samples were evaluated by RUNX3 staining and subclassified by immunophenotype. H. pylori infection in dysplastic lesions and the normal surrounding tissue was examined by silver staining, and cagA status was assessed by polymerase chain reaction. The loss of RUNX3 expression was observed in 62 cases (57.9%), and an association with H. pylori infection was found in 54 cases (50.5%). The infection rate with the cagA-positive H. pylori strain was 63.0%. In RUNX3-negative lesions, the rate of H. pylori infection (p=0.03) and the frequency of category 4 lesions (according to the revised Vienna classification) were high (p=0.02). In addition, the gastric mucin phenotype was predominant. In RUNX3-negative category 4 lesions, the rate of cagA-positive H. pylori infection rate was high but not significantly increased (p=0.08). Infection with H. pylori is associated with inactivation of RUNX3 in early gastric carcinogenesis. This mechanism was prominent in gastric cancer with a gastric mucin phenotype.Gut and Liver 11/2013; 7(6):688-95.
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ABSTRACT: Runt-related transcription factor 3 (RUNX3) is a member of the runt-domain family of transcription factors and has been reported to be a candidate tumor suppressor in gastric cancer. However, the association between RUNX3 promoter methylation and gastric cancer remains unclear. We systematically reviewed studies of RUNX3 promoter methylation and gastric cancer published in English or Chinese from January 2000 to January 2011, and quantified the association between RUNX3 promoter methylation and gastric cancer using meta-analysis methods. A total of 1740 samples in 974 participants from seventeen studies were included in the meta-analysis. A significant association was observed between RUNX3 promoter methylation and gastric cancer, with an aggregated odds ratio (OR) of 5.63 (95%CI 3.15, 10.07). There was obvious heterogeneity among studies. Subgroup analyses (including by tissue origin, country and age), meta-regression were performed to determine the source of the heterogeneity. Meta-regression showed that the trend in ORs was inversely correlated with age. No publication bias was detected. The ORs for RUNX3 methylation in well-differentiated vs undifferentiated gastric cancers, and in intestinal-type vs diffuse-type carcinomas were 0.59 (95%CI: 0.30, 1.16) and 2.62 (95%CI: 1.33, 5.14), respectively. There were no significant differences in RUNX3 methylation in cancer tissues in relation to age, gender, TNM stage, invasion of tumors into blood vessel or lymphatic ducts, or tumor stage. This meta-analysis identified a strong association between methylation of the RUNX3 promoter and gastric cancer, confirming the role of RUNX3 as a tumor suppressor gene.BMC Gastroenterology 08/2011; 11:92. · 2.11 Impact Factor
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ABSTRACT: Underexpression of the gene runt-related transcription factor 3 (RUNX3), an important tumor suppressor, is known to contribute to gastric cancer progression. However, the mechanism underlying aberrant RUNX3 expression has not been fully elucidated. We investigated the role of microRNA-148a (miR-148a) and DNA methyltransferases (DNMTs) in RUNX3 promoter methylation and gene expression. RUNX3 mRNA, RUNX3 protein, and methylation levels were assayed in human gastric cancer tissues and matched normal tissues, and AGS and BGC-823 cells by real-time reverse transcription PCR, Western blot, and methylation-specific PCR, respectively. A correlation between RUNX3 mRNA levels and that of miR-148a was also investigated in gastric cancer tissues. We found that RUNX3 mRNA levels were significantly downregulated in gastric cancer tissues compared with their matched normal tissues, and were closely associated with miR-148a expression. After treatment of human gastric cancer AGS and BGC-823 cells with the DNA methylation inhibitor 5-aza-2'-deoxycytidine, a significant increase in RUNX3 mRNA, RUNX3 protein, and the non-methylated form of the RUNX3 promoter were observed relative to untreated cells. Enforced expression of miR-148a, which can modulate DNMT1 and DNMT3B, also increased the expression of RUNX3 in gastric cancer cells. Knockdown of DNMT1 was associated with increased levels of RUNX3 mRNA and RUNX3 protein, while knockdown of DNMT3B did not have any effect on these in BGC-823 cells. Our results show that miR-148a may regulate RUNX3 expression through modulation of DNMT1-dependent DNA methylation in gastric cancer and highlight a miRNA-epigenetics regulation mechanism of gene expression.Molecules and Cells 03/2013; · 2.21 Impact Factor