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PURPOSE: Emerging evidence indicates that runt-related transcription factor 3 (RUNX3) is an important tumor suppressor gene in several cancer types, including colorectal cancer (CRC). However, the clinical significance of RUNX3 inactivation in CRC remains unclear. The aim of this study was to examine the correlation between clinicopathologic factors and RUNX3 hypermethylation/expression in CRC. METHODS: Sixty-two CRC patients who were treated at the Soonchunhyang University College of Medicine were recruited in this study. The hypermethylation of CpG islands in the RUNX3 promoter and the expression of RUNX3 mRNA were identified by methylation-specific polymerase chain reaction (PCR) and reverse transcriptase-PCR, respectively. The expression of RUNX3 was determined by immunohistochemical staining. RESULTS: Of the 62 CRC tissue samples, 20 (32.3%) presented hypermethylated RUNX3 promoters. Aberrant RUNX3 hypermethylation was found to be associated with vascular (P = 0.006) and lymphatic (P = 0.002) invasion. Hypermethylation of RUNX3 was associated with poor survival outcomes (P = 0.038). However, expression of RUNX3 was not a prognostic factor (P = 0.363). CONCLUSION: Hypermethylation of RUNX3 may be a predictor of a poor prognosis in CRC.
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Humans , Colorectal Neoplasms , Core Binding Factor Alpha 3 Subunit , CpG Islands , Epigenomics , Genes, Tumor Suppressor , Immunohistochemistry , Methylation , Polymerase Chain Reaction , Prognosis , RNA, Messenger , Transcription Factor 3ABSTRACT
Objective To investigate the role of RUNX3 in the regulation of macrophage polarization so as to provide a new therapeutic approach for immunity-related diseases.Methods ① After RAW264.7 cells were stimulated by IFN-γ,LPS and IL-4,respectively,the expressions of their surface markers(arginase-1 and iNOS) were detected by RT-PCR to observe whether RAW264.7 cells polarized to M1 or M2 after stimulation by IFN-γ, LPS and IL-4.The cells stimulated by IFN-γ and LPS were named group M1 and those stimulated by IL-4 were group M2;the control group was group M0.② The expression of RUNX3 was detected by immunofluorescence and RT-PCR methods in each cell group(M1,M2 and M0).③ RUNX3 over-expression vector was established.The RUNX3 gene in RAW264.7 cells was silenced.Cell lines with stable expression were screened with G 418 culture medium.The expressions of cell surface markers iNOS and CD86 were detected by RT-PCR;cell secretion(TNF-α) was detected using ELESA method.Results ① Stimulation of RAW264.7 cells with IFN-γ and LPS could induce RAW264.7 cells to polarize into M1 type macrophages.The mRNA expression of iNOS in M1 group was higher than that in group M0 detected by RT-PCR(P= 0.002),while using IL-4 to stimulate RAW264.7 cells could induce RAW264.7 cells to polarize into M2 macrophages.The results of RT-PCR detection showed that the expression of arginase-1 was higher in M2 group than in group M0(P=0.021).② The expression of RUNX3 mRNA in the M1 cells group was higher than that in the M0 cells group(P= 0.001),but the expression in the M2 cells group was decreased(P=0.041).③ After silencing of RUNX3,the expressions of RAW264.7 cell surface markers CD86 and iNOS(P=0.005)and the cells secretion of TNF-α(P＜0.001)were decreased compared with those in the control group.Conclusion RUNX3 transcriptional activation may promote the differentiation of macrophages into M1 type.
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Objective:To study the clinical value of peripheral blood Runx3 gene CpG island's methylation in the evaluation of colon cancer's disease condition and prognosis.Methods:Methy1ation specific PCR was used to detect the Runx3 gene CpG island's methylation by Peripheral blood in colon cancer patient (observation group) and healthy people (control group).The Runx3 gene CpG island's methylation rates in different clinicopathological factors were compared.The 3 year survival rate and total survival time between patient with Runx3 gene CpG island's methylation and unmethylation were Compared.Result:The Runx3 gene CpG island's methylation rate in observation group was significantly higher than in control group (P＜0.05).The Runx3 gene CpG island's methylation rates in degree of differentiation,maximum tumor diameter,lymph node metastasis,distant metastasis,TNM staging and surgical resection were significant different (P＜0.05).The 3 year survival rate and total survival time in patient with Runx3 gene CpG island's methylation were significantly higher than in patient with Runx3 gene CpG island's unmethylation.Conclusion:Runx3 gene CpG island is hypermethylated in colon cancer's peripheral blood,which has value in the evaluation of colon cancer's disease condition and prognosis.
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Purpose To evaluate the relationship between the expression of Runx-3 and β-catenin protein in EGC with the clinical factors.Methods Immunohistochemistry (IHC) was used to detect the expression of Runx-3 and β-catenin protein in 30 cases of normal gastric mucosa and 49 cases of EGC.Results The expression rate of Runx-3 protein in normal gastric mucosa (86.67％) was significantly higher than that in EGC tissues (34.69％) (P ＜ 0.05).β-catenin staining was strongly positive (100％) in normal gastric mucosa compared with that in EGC (57.14％) (P ＜ 0.05),while the abnormal expression rate of β-catenin (0) was significantly lower than that in EGC tissues (75.51％) (P ＜ 0.05).No correlation was found between the expression of Runx-3 and β-catenin protein with the clinicopathological factors,including sex,age,and tumor size except vessel invasion.Conclusion The reduced expression of Runx-3 in EGC indicates that it may be used as a favorable marker for the diagnosis of EGC.The loss of β-catenin protein membrane expression while ectopic expressed on nuclear or cytoplasm in EGC and the membrane expression of β-catenin protein is completely absent in the early stage of vascular invasion suggesting that the expression of β-catenin protein is closely related to the occurrence and development of EGC.A join-detection of Runx-3 and β-catenin expression will be helpful for the diagnosis of EGC.
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Objective To study the expression of RUNX3 in colorectal adenocarcinoma tissues and its correlation with microvessel density (MVD), and investigate the clinical pathological prognostic significance of RUNX3 and MVD in patients with colorectal cancer. Methods The expression value of RUNX3 and MVD in 70 specimens’ colorectal adenocarcinoma tissues were detected by immunohistochemistry staining technique. The correlation between their expression and the clinicopathologic features was also investigated. Results The expression value of RUNX3 and the positive rates of RUNX3 in colorectal adenocarcinoma tissues were 3.25 ± 1.14 and 25.71% (18/70). The expression value of MVD in colorectal adenocarcinoma tissues was 13.14 ± 3.23. Expression of RUNX3 and MVD value were correlated with CEA, serosal invasion, liver metastasis, lymph node metastasis, and TNM stage (P < 0.01). The expression value of RUNX3 had negative correlations with that of MVD. Conclusions The high expression of RUNX3 could inhibit tumor microvascular generation in order to have negative control response on invasion and distant metastasis.
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OBJECTIVE@#To study the expression of RUNX3 in colorectal adenocarcinoma tissues and its correlation with microvessel density (MVD), and investigate the clinical pathological prognostic significance of RUNX3 and MVD in patients with colorectal cancer.@*METHODS@#The expression value of RUNX3 and MVD in 70 specimens' colorectal adenocarcinoma tissues were detected by immunohistochemistry staining technique. The correlation between their expression and the clinicopathologic features was also investigated.@*RESULTS@#The expression value of RUNX3 and the positive rates of RUNX3 in colorectal adenocarcinoma tissues were 3.25 ± 1.14 and 25.71% (18/70). The expression value of MVD in colorectal adenocarcinoma tissues was 13.14 ± 3.23. Expression of RUNX3 and MVD value were correlated with CEA, serosal invasion, liver metastasis, lymph node metastasis, and TNM stage (P < 0.01). The expression value of RUNX3 had negative correlations with that of MVD.@*CONCLUSIONS@#The high expression of RUNX3 could inhibit tumor microvascular generation in order to have negative control response on invasion and distant metastasis.
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Background:Chronic atrophic gastritis(CAG)is a kind of chronic gastritis with atrophic changes of gastric mucosa. The studies on peripheral blood biomarkers in CAG are rare. Aims:To investigate the methylation of peripheral blood CpG sites in Runx3 gene promoter region in CAG patients. Methods:Eighty-two mild CAG patients,73 moderate to severe CAG patients from June 2013 to May 2014 at Daqing Oilfield General Hospital were enrolled,and 45 patients with normal gastric mucosa were served as controls. The methylation of CpG sites in Runx3 gene promoter region was measured by MALDI-TOF-MS. mRNA expression of Runx3 was determined by fluorescent quantitative PCR,and the protein expression of Runx3 was determined by Western blotting. Results:Compared with the control group and mild CAG group,methylation levels of CpG13,CpG14 and CpG15 sites in Runx3 gene promoter region were significantly increased in moderate to severe CAG group(P 0. 05 ). Conclusions:The hypermethylation of peripheral blood CpG13,CpG14 and CpG15 sites in Runx3 gene promoter region can inhibit the expression of Runx3 in CAG patients,and can be used potentially as the biomarker for clinical staging of CAG.
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Objective To investigate the impact of down-regulation of histone methyltransferase enhancer of zeste homolog 2 (EZH2) on RUNX3 expressions,proliferation and apoptosis in human pancreatic cancer.Methods The expressions of EZH2 and RUNX3 in 38 pancreatic cancer patients and human pancreatic cancer AsPC-1,PANC-1 and BxPC-3 cells were detected by immunohistochemistry and western blot,respectively.Cells were transfected with siEZH2 by lipofectamin 2000.Real time-PCR and western blot were used to detect EZH2 and RUNX3 expressions.Cell growth and apoptosis in vitro and vivo were assessed by MTT,flow cytometry and nude mice experiments,respectively.The correlation among the expressions of EZH2,clinical pathological features and overall survival rate were analyzed.Results Elevated EZH2 and decreased RUNX3 expressions were observed in human pancreatic cancer tissues and cells (P ＜ 0.05).Knockdown of EZH2 reduced cell growth and induced apoptosis in vitro and vivo by upregulating RUNX3 protein expression (P ＜ 0.05).In addition,the EZH2 expressions were correlated with tumor stage,lymph node metastasis and poor prognosis (P ＜ 0.05).Conclusions EZH2 expressions were correlated with malignancy and poor prognosis in pancreatic cancer.Tumor cell proliferation was promoted by EZH2 through down-regulation of RUNX3.EZH2 may be a potential therapeutic target for pancreatic cancer.
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Objective To investigate the expressions and clinical significances of Runt-domain-related 3 (Runx3) and chromodomain helicase DNA-binding protein 5 (CHD5) in colorectal cancer.Methods Ninety-six colorectal cancer tissue samples and matched adjacent normal tissues and 72 colorectal adenoma tissues were collected.Real-time quantitative polymerase chain reaction (qRT-PCR) and Western blotting were used to detect the mRNA and protein expression of Runx3 and CHD5.The associations of Runx3 and CHD5 expression with clinical pathological characteristics,diagnostic value and prognosis relationship of patients were further analyzed.Results Runx3 and CHD5 relative expressions of mRNA and protein were 0.35 ± 0.00,0.28 ± 0.02 and 0.26 ± 0.02,0.31 ± 0.01,which were significantly lower than those in the matched adjacent tissues 0.95 ± 0.02,0.92 ± 0.02 and 0.89 ± 0.03,0.93 ± 0.02 (t =2.36,P ＜ 0.05;t =1.25,P ＜ 0.05;t =1.37,P ＜ 0.05;t =1.13,P ＜ 0.05) and colorectal adenoma tissues 0.89 ± 0.02,0.90 ± 0.02 and 0.85±0.02,0.87±0.04 (t=2.27,P＜0.05;t=2.16,P＜0.05;t=1.25,P＜0.05;t=2.65,P＜0.05).Runx3 and CHD5 expressions differed significantly between tumors with different TNM stages (x2 =4.65,P =0.031;x2 =7.89,P =0.005),depths of tumor invasion (x2 =4.17,P =0.041;x2 =4.86,P =0.028),lymph node statuses (x2 =4.20,P =0.040;x2 =7.02,P =0.008),or histological differentiation (x2 =7.31 P =0.036;x2 =9.54,P =0.023).Linear correlation analysis showed that the expressions of the two genes were positively correlated (r =0.572,P =0.001).Receiver operating characteristic (ROC) curve showed that Runx3 and CHD5 had diagnostic value (AUC were 0.712,0.745;sensitivity and specificity were 45.9％,52.5％ and 83.6％,81.4％ respectively).Runx3 and CHD5 both low expression group compared with the other patient groups in overall survival time (x2 =8.156,P ＜ O.05) and progression-free survival (x2 =6.325,P ＜ 0.05) had statistically significant differences.Conclusion Runx3 and CHD5 are low expressed in colorectal cancer and may prove useful as biomarkers for diagnosis target and prognostic indication in patients with colorectal cancer.
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Background:Tissue microarray has been increasingly used in research of malignancies. It has been revealed that TGF-β signaling pathway contributes to the tumorigenesis and progress of malignancies. Aims:To determine the expressions of Runx3,Smad4,Cdk2 and p21,the key molecules in TGF-β signaling pathway by tissue microarray,and investigate their correlations with clinicopathological features and prognosis of gastric cancer. Methods:A total of 378 paraffin embedded tissue blocks,including 130 gastric cancer tissue and 248 para-cancer tissue from 130 patients undergoing radical resection of gastric cancer were obtained. Tissue microarray and immunohistochemistry were used to determine the expressions of Runx3,Smad4,Cdk2 and p21. Results:The aberrant expression rates of Runx3,Smad4, Cdk21 and p21 in gastric cancer tissue were significantly higher than those in para-cancer tissue(67. 7% ,35. 4% , 63. 8% and 70. 0% vs. 14. 1% ,12. 5% ,18. 1% and 37. 1% ,P < 0. 05,respectively). Aberrant expression of Runx3 was closely correlated with histological grade and lymph node metastasis of gastric cancer( P < 0. 05),while aberrant expressions of Smad4 and p21 were correlated with histological grade only(P < 0. 05);aberrant expression of Cdk2 was correlated with histological grade,lymph node metastasis and TNM staging(P < 0. 05). Pairwise correlations were seen among aberrant expressions of Runx3,Smad4 and p21 in gastric cancer,while Cdk2 was correlated with Runx3 only. Kaplan-Meier survival curve showed that 5-year survival rates in Runx3,Smad4 and p21 aberrant expression groups were significantly lower than those in normal expression groups(P <0. 05). Furthermore,Cox proportional hazard model indicated that Runx3 and Smad4 were independent prognostic factors for gastric cancer. Conclusions:Runx3,Smad4,Cdk2 and p21 might play pivotal roles in tumorigenesis and progression of gastric cancer. As interactions occurred among these four proteins,whether Runx3 and Smad4 could be used for predicting the prognosis of gastric cancer needs to be further studied.
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BACKGROUND/AIMS: Helicobacter pylori cytotoxin-associated gene A (CagA) has been suggested to be involved in the inactivation of Runt-related transcription factor 3 (RUNX3), a known gastric carcinoma tumor suppressor gene. It remains unclear how H. pylori CagA initiates or maintains RUNX3 promoter methylation and inactivates its protein expression in gastric carcinoma. METHODS: RUNX3 promoter methylation status, RUNX3 expression, and H. pylori CagA were investigated in 76 sample pairs of gastric carcinoma tissue. The patients' medical records were reviewed. The association between RUNX3 methylation or loss of RUNX3 expression and clinicopathologic variables according to H. pylori CagA status were investigated. RESULTS: In gastric carcinoma patients with H. pylori CagA-positive infection, RUNX3 methylation did not show association with lymphatic invasion, venous invasion, and TNM stages. However RUNX3 methylation was observed more frequently in poorly differentiated adenocarcinoma and signet ring cell carcinoma (77.8% vs. 20.0%, p=0.023) in early stage. In gastric carcinoma patients with H. pylori CagA-positive infection, loss of RUNX3 expression did not show association with lymphatic invasion, venous invasion, and TNM stages. However loss of RUNX3 expression was observed more frequently in early gastric carcinoma than in advanced gastric carcinoma (84.2% vs. 75.0%, p=0.51), but this difference was not significant. CONCLUSIONS: In gastric carcinoma patients with H. pylori CagA-positive infection, RUNX3 methylation or loss of RUNX3 expression did not show correlation with lymphovascular invasion and TNM stages. In early gastric carcinoma patients with H. pylori CagA-positive infection, RUNX3 methylation was observed more in poorly differentiated adenocarcinoma and signet ring cell carcinoma.
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Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Antigens, Bacterial/metabolism , Bacterial Proteins/metabolism , Cell Line, Tumor , Core Binding Factor Alpha 3 Subunit/genetics , Gene Expression Regulation, Neoplastic , Helicobacter Infections/complications , Helicobacter pylori/isolation & purification , Immunohistochemistry , Lymphatic Metastasis , Methylation , Neoplasm Staging , Promoter Regions, Genetic , Retrospective Studies , Stomach Neoplasms/complicationsABSTRACT
The study of RunX3 in tumor pathogenesis is a rapidly expanding area of cancer research.Functional inactivation of RunX3 is frequently observed in tumors of diverse origins.RunX3 can bind directly to the TGF-β signaling effectors for synergistic induction,enhancing the growth inhibitory effect of TGF-β signal pathway.Additionally,RunX3 can also bind to the complex TCF4-β-catenin in Wnt signal pathway for inhibiting its tumorigenicity.Through the two signal pathway mentioned above,RunX3 can regulate the epithelial mesenchymal transitions process.Moreover,the transcription of claudin-1 can be directly regulated by RunX3.RunX3 has also been described to have an oncogenic function in a subset of tumors,but how RunX3 switches from tumor suppression to oncogenic activity is yet unknown.This review focuses on summarizing the important findings about the mechanism and relative signal pathway of RunX3 in tumor suppression from the articles published recently.
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Objective To study methylation status of the Runx3 gene in occurrence and development of children malignant lymphoma.Methods The bone marrow specimens of 48 children diagnosed as malignant lymphoma were included into experimental group.20 children with non-malignancy were included into control group.Methylation-specific polymerase chain reaction (MS-PCR) was used to detect methylation status of Runx3 gene in bone marrow cells.The reverse transcription-polymerase chain reaction (RT-PCR) was used to detect mRNA expression of Runx3 gene.Results MS-PCR assay results showed that 31 cases expressed Runx3 gene methylation in experimental group,the positive rate was 64.6 ％ (31/48),but no one was detected in control group (20 cases),the difference between two groups was significant (x2 =15.7,P ＜0.05).Dynamic observation of 42 cases in experimental group showed the declining of Runx3 methylation positive rate.RT-PCR assay results showed that all 20 cases in the control group expressed Runx3 gene mRNA,all cases with methylation status of the Runx3 gene in the experimental group didn’ t expressed Runx3 gene mRNA.In experimental group,9 cases of clinical remission expressed Runx3 gene mRNA,and 1 case of relapsed didn’ t expressed Runx3 gene mRNA.Conclusion Runx3 gene shows a high methylation status in bone marrow cells of malignant lymphoma children,so that blocked the expression of Runx3 gene,which is closely related to the occurrence and development of children malignant lymphoma.
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Objective To study the expression of RUNX3 mRNA in primary liver cancer (PHC) tissue and its surrounding normal tissue,and its clinical significance.MethodsReverse transcription polymerase chain reaction (RT-PCR) was performed to detect the expression of RUNX3 mRNA in tumor and peritumor tissues in 51 patients with PHC.The relationship between RUNX3 mRNA expression and some clinical pathological parameters was analyzed.ResultsThe relative expression values of RUNX3 mRNA in the tumor tissue and the surrounding normal tissue were 0.4509±0.0963 and 0.9147± 0.0222,respectively.The difference was significant (t=33.6087,P＜0.001).The RUNX3 mRNA expression in tumor tissue correlated with some clinical pathological parameters including low tumor differentiation,positive cancer embolus and intrahepatic invasion and metastasis.The RUNX3 mRNA expression was not correlated with other clinicopathological parameters including gender,cancer diameter,cancer location,hemorrhage and necrosis of cancer,and histotype.ConclusionRUNX3 may be a new tumor suppressor gene for PHC.
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BACKGROUND/AIMS: The relationship between Runt-related transcription factor 3 (RUNX3) gene inactivation and various solid tumors has been reported; however, little information is available about RUNX3 in thyroid cancers. METHODS: We evaluated the DNA methylation of RUNX3 in 13 papillary thyroid cancer tissues and four thyroid cancer cell lines. Additionally, using reverse transcriptase-polymerase chain reaction, we analyzed RUNX3 gene expression in several thyroid cancer cell lines after treating with the demethylating agent 5-aza-2'-deoxycytidine (DAC). RESULTS: RUNX3 was hypermethylated in many thyroid cancer cell lines and in 10 of the 12 papillary thyroid cancer tissues. Treatment with DAC increased the expression of RUNX3 in some thyroid cancer cell lines. CONCLUSIONS: We suggest that RUNX3 is associated with thyroid carcinogenesis, and RUNX3 methylation is a potentially useful diagnostic marker for papillary thyroid cancer.
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Humans , Azacitidine/analogs & derivatives , Carcinoma/genetics , Cell Line, Tumor , Core Binding Factor Alpha 3 Subunit/genetics , DNA Methylation/drug effects , Gene Expression/drug effects , Thyroid Neoplasms/genetics , Biomarkers, Tumor/geneticsABSTRACT
Objective To investigate the expressions of RUNX3 and CyclinDl in pancreatic carcinoma and their significance. Methods Expressions of RUNX3, CyclinD1 in 47 cases with pancreatic carcinoma, 18 cases with cystadenoma of pancreas and 12 normal pancreas cases were detected by immunohistochemistry, and the relationship between their expressions and clinicopathological parameters was analyzed. Results The positive expression rates of RUNX3 in pancreatic carcinoma, cystadenoma of pancreas, normal pancreas cases were 57.4％ (27/47), 94.4％ (17/18), 100％ (12/12); the positive expression rates of CyclinD1 in pancreatic carcinoma, cystadenoma of pancreas, normal pancreas cases were 72.3％ (34/47), 44.4％(8/18), 8.3％ (1/12). RUNX3 expression was not related to the age and sex, but it was negatively associated with clinical staging, lymph node metastasis, the differentiation degree (P ＜0.05 ). CyclinD1 expression was not related to the age and sex, but it was positively associated with clinical staging, lymph node metastasis, the differentiation degree (P ＜0.05 ). The expression of RUNX3 and CyclinD1 was negatively associated (r = - 0.375, P = 0.009). Conclusions The expression of RUNX3 is decreased in pancreatic carcinoma. The expression of CyclinD1 is increased in pancreatic carcinoma. They may play an important role in the carcinogenesis and progression of pancreatic carcinoma.
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Objective To investigate the relationship between the methylation of CpG island of RUNX3 gene promoter and its expression in a human cutaneous malignant melanoma cell line A375, and to assess the role of RUNX3 gene methylation in the pathogenesis of human cutaneous malignant melanoma. Methods Cultured A375 cells were treated with various concentrations (0, 1, 5, 10, 20 μmol/l) of 5-azacyti-dine for 24 or 72 hours followed by another 5 days of culture. Then, methylation-specific PCR (MSP) was performed to evaluate the methylation status of RUNX3 promoter region, and Western-blot analysis to detect the protein expression of RUNX3 in A375 cells. Results The RUNX3 gene promoter region was hypermethylated in untreated A375 cells, along with the absence of protein expression of RUNX3. However, after the treatment with 5-azacytidine, the promoter region of RUNX3 gene was demethylated partly, and the expression of RUNX3 protein was restored in A375 cells. Further, the expression intensity was directly correlated with the concentration of 5-azacytidine. Conclusions The promoter hypermethylation of RUNX3 gene may be related to the silencing of RUNX3 gene expression in A375 cells, whereas 5-azacytidine can cause the demethylation of RUNX3 gene, reactivate the gene which has been inactivated by the promoter hypermethylation, and finally induce the re-expression of RUNX3 protein.
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AIM: To construct the replicative defecient adenovirus Ad-Runx3 expressing Runx3, and to express it in U251 malignant glioblastoma cells. METHODS: The runx3 gene with a flag tag was amplified by PCR using pCMV5-AML2 as a template, and was confirmed by DNA sequencing. The adenovirus shuttle vector pShuttle-CMVRunx3 was constructed by introducing runx3 DNA fragment into the sites of Kpn Ⅰ and Xho Ⅰ of pShuttle-CMV vector. This recombinant plasmid was linearized by Pmel and electronically transfected into BJ5183 cells to get the recombinant adenovirus vector Ad-Runx3. The recombinant adenovirus expressing Runx3 was infected into U251 malignant glioblastoma cells. The expression of exogenous Runx3 was observed by immonoblotting and its localization was detected by immunostaining using anti-Flag tag antibody. RESULTS: The recombinant adenovirus expressing Runx3 with a Flag tag was constructed and infected into U251 glioblastoma cells. The exogenous Runx3 protein was detected only in the nuclei. CONCLUSION: The recombinant adenovirus expressing Runx3 with a Flag tag is constructed successfully, and the Runx3 protein expressed in the nuclei of infected cells. The study laid a foundation for further research of the function of Runx3 in gliocarcinogenesis.
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PURPOSE: Transcriptional silencing of tumor suppressor genes by aberrant methylation of CpG islands plays a crucial role in the development of human cancers. We comprehensively examined the methylation status of several tumor suppressor genes in osteosarcoma with a special focus on the RUNX3 gene. MATERIALS AND METHODS: Methylation-specific polymerase chain reaction (MSP) was performed for osteosarcoma tissues and their cell lines. MSP and RT-PCR for the RUNX3 gene were performed in the tumor-derived cell lines and the immortalized cell lines. The demethylating agent 5-aza-2' deoxycytidine was used in the SaOS-2 cell line to reverse the methylation status. RESULTS: Hypermethylation of the RUNX3 gene was observed in 60% (24 of 40) of the osteosarcoma tissues, whereas other tumor suppressor genes showed very low methylation. Thirteen of 30 (43%) tumor-derived cell lines, and U-2OS and SaOS-2 showed hypermethylation of the RUNX3 gene on MSPCR. However, RUNX3 was expressed in the SaOS-2 cell line, as determined by RT-PCR, and the expression was augmented by treatment with 5-aza-2' deoxycytidine. CONCLUSION: Our study suggests that aberrant methylation is an important mechanism of RUNX3 down-regulation in osteosarcoma. This data may have potential significance in developing a potential therapeutic target for osteosarcoma.
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Humans , Cell Line , CpG Islands , Deoxycytidine , Down-Regulation , Genes, Tumor Suppressor , Methylation , Osteosarcoma , Polymerase Chain ReactionABSTRACT
Purpose To investigate the relationship between the expression of Runx3 protein and pathogenesis, development,clinicopathological features and its prognostic significance in gastric adenocarcinoma.Methods Immunohistochemical SP method was used to detect the expression of Runx3 protein in 63 cases of gastric cancer,19 cases of atypical hyperplasia and 10 cases of normal gastric mucosa obtained from patients whose partial gastrotomy was performed for benign diseases.Results Compared with gastric atypical hyperplasia tissue (68.4%) and normal gastric mucosa (90%), the positive rate of Runx3 protein in gastric cancer (39.7%) was significantly lower (P＜0.05); the expression of Runx3 protein was related to tumor differentiation, invasive depth and lymphnode metastasis, but not to age, sex, tumor size and TNM stages; the survival rate of the patients with Runx3 protein expression was higher than that without Runx3 expression (P＜0.05).Conclusion Runx3 protein may play an important role in the occurrence and development of gastric cancer, and it is an important marker in evaluating the prognosis of the patients.