RESUMO
Purpose To investigate the effect of DAPPER1 on the malignant biological behavior in esophageal carcinoma cells,and further to analyze the expression and the possible regulated mechanism of DAPPER1 in esophageal squamous cell cancer (ESCC) samples.Methods MTT assay,colony formation assay and wound healing were used to examine the effect of DAPPER1 on malignant biological behavior in esophageal carcinoma cells,RT-PCR and MSP methods were applied respectively to examine the expression and the methylation status of DAP-PER1 in three ESCC cell lines (TE13,T.Tn,Eca109).Immunohistochemistry was used to examine the DAPPER1 protein expression.Results The negative or weak expression of DAP-PER1 was detected in ESCC cell lines.After treated with 5-Aza2'-deoxycytidine (5-Aza-dC,a demethylation agent),the expression level of DAPPER1 was obviously increased.Meanwhile,over expression of DAPPER1 or treated with 5-Aza-Dc could obviously inhibit proliferation and immigration abilities of TEl3 cell line.The level of DAPPER1 expression had no obviously change after treated with trichostatin A (TSA).Decreased protein expression of DAPPER1 was observed in ESCC tumor tissues compared with non-cancerous tissues (P ＜ 0.01),and associated with the methylation status of this gene (P ＜ 0.01).Conclusion DAPPER1 plays an important role of tumor suppressor gene in esophageal carcinoma,and the aberrant hypermethylation may be one of the main mechanisms in abnormal expression of this gene.
RESUMO
Objective To investigate the expressions of Dapper1 in gastric carcinoma and elucidate its relationship with survivin and its role in tumor cell apoptosis. Methods Dapper1 mRNA was detected with RT-PCR using specimens from 30 cases of gastric carcinoma and the corresponding normal gastric mucosa.The pcDNA3.1-Dpr1 plasmid was transfected into SGC-7901 cells with LipofectamineTM 2000.The effect of upregulation of Dpr1 on SGC7901 cell apoptosis was determined by flow cytometry.The downregulation of survivin、Dvl-2 and β-catenin protein expression were detected by Western blot analysis.Results Downregulation of Dpr1 gene expression was observed in 17(57%)of 30 human gastric cancer and the downregulation was significantly correlated with the depth of invasion and the degree of differentiation (P＜0.05).Also,upregulation of Dpr1 mRNA and downregulation of survivin mRNA were detected after transfecting pcDNA3.1-Dpr1 plasmid in SGC7901 cells,which led to downregulation of survivin、Dvl-2、β-catenin protein and increase of the SGC7901 cell apoptosis rate from 2.89%to 13.96%.Conclusion Downregulation of Dp1l gene expression is common in human gastric carcinoma,and upregulation of Dpr1 results in significant inhibition of survivin expression which can induce apoptosis of SGC7901 cells.