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: Runx3, a member of Runt-related transcription factor (Runx) proteins with tumor suppressor effect, is a tissue-restricted and cancer related transcription factor that regulate cell proliferation and growth, as well as differentiation. In the present study, exogenous Run3 was transiently expressed in AGS (human gastric adenocarcinoma), with undetectable Runx3 protein and in A549 (human lung carcinoma) with low levels of endogenous Runx3 protein. The GFP tagged Runx3 was transfected into AGS and A549 cells using fugene6 and PolyFect and Runx3 expression was confirmed by fluorescent microscopy and RT-PCR. The effect of Runx3 transfection on cell proliferation was determined by MTT assay and the results were confirmed by the trypan blue dye exclusion method. The effect of Runx3 expression on mRNA expression of BCL2-associated X protein (Bax) was evaluated using RT-PCR. In AGS and A549 cells, Runx3 expression inhibited cell proliferation (p < 0.01). The growth inhibition was less in A549 cells. We show that Runx3 expression increases Bax mRNA expression in AGS cells when compared with control (p < 0.05), but no significant differences in mRNA expression was observed in both examined cells. Runx3 expression has antiproliferative effect in AGS cell perhaps via increase in expression of Bax. The effect of Runx3 on A549 cells' viability which has endogenous level of Runx3 is not related to Bax. These findings implicate a complex regulation by Runx3 in inhibition of cell proliferation utilizing Bax.Iranian journal of pharmaceutical research (IJPR) 01/2011; 10(2):355-61. · 0.54 Impact Factor
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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: RUNX3 (runt-related transcription factor-3) has been reported to suppress tumor tumorigenesis and metastasis in different human cancers. In this study, we used tissue microarray (TMA) to determine the significance of RUNX3 in prostate cancer progession. Our results showed ectopic expression of RUNX3 in prostate cancer tissues when compared with tumor adjacent normal prostate tissues, and reduced RUNX3 staining was significantly correlated with TNM stage. Moreover, we demonstrated that RUNX3 overexpression inhibited prostate cancer cell migration and invasion resulting from the elevated upregulation of tissue inhibitor of matrix metalloproteinase-2 (TIMP-2), which subsequently inhibited metalloproteinase-2 (MMP-2) expression and activity in vitro. Knock down of RUNX3 expression broke up the balance of TIMP-2/MMP-2, whereas silence of TIMP-2 resulted in the inhibition of MMP-2 expression in prostate cells. We also showed that restoration of RUNX3 decreased vascular endothelial growth factor (VEGF) secretion and suppressed endothelial cell growth and tube formation. Strikingly, RUNX3 was demonstrated to inhibit tumor metastasis and angiogenesis in vivo. Altogether, our results support the tumor suppressive role of RUNX3 in human prostate cancer, and provide insights into development of targeted therapy for this disease.PLoS ONE 01/2014; 9(1):e86917. · 3.53 Impact Factor