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Objective To observe the effect of different expression levels of USP28 on the radiosensitivity of ECA109 cells by gene transfection method,aiming to provide theoretical basis for comprehensive treatment of esophageal cancer.Methods The expression levels of USP28 and c-Myc in the esophageal epithelial cells Het-1A,ECA109 and ECA109R were quantitatively measured by qRT-PCR.The specific siRNA sequences were designed according to the USP28 and c-Myc genes.The pcDNA-USP28 and pcDNA-c-Myc plasmids were constructed.The esophageal cancer cell ECA109 was transfected with Lipofectamine 2000 to observe the transfection effect and related protein expression.ECA109 and ECA109R cells were exposed to 6 Gy X-ray radiation.The cell apoptosis in each group was detected by flow cytometry.The radiosensitivity was evaluated by clone formation assay.Results The expression levels of USP28 and c-Myc in ECA109 were significantly higher than those in Het-1A (both P＜0.05),and the expression levels of USP28 and c-Myc in ECA109R were remarkably higher than those in ECA109(both P＜0.05).The pcDNA-USP28 and pcDNA-c-Myc recombinant plasmids were successfully constructed.Compared with the negative control group,the expression of USP28 at the protein and mRNA levels in the si-USP28 group was significantly down-regulated,whereas those in the pcDNA-USP28 group were remarkably up-regulated.Similar results were obtained in terms of c-Myc.Compared with the control group,the expression level of c-Myc protein was significantly up-regulated in the pcDNA-USP28 group,whereas considerably down-regulated in the si-USP28 group.After 6 Gy irradiation,the apoptosis rate and radiosensitivity of ECA109 cells were significantly declined.The apoptosis rate and radiosensitivity of ECA109R cells were increased in the si-USP28 group.Conclusions The expression of USP28 protein is closely correlated with the radiosensitivity of esophageal cancer cells.The underlying mechanism may be related to the regulation of c-Myc expression by USP28.
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Objective@#To observe the effect of different expression levels of USP28 on the radiosensitivity of ECA109 cells by gene transfection method, aiming to provide theoretical basis for comprehensive treatment of esophageal cancer.@*Methods@#The expression levels of USP28 and c-Myc in the esophageal epithelial cells Het-1A, ECA109 and ECA109R were quantitatively measured by qRT-PCR. The specific siRNA sequences were designed according to the USP28 and c-Myc genes. The pcDNA-USP28 and pcDNA-c-Myc plasmids were constructed. The esophageal cancer cell ECA109 was transfected with Lipofectamine 2000 to observe the transfection effect and related protein expression. ECA109 and ECA109R cells were exposed to 6 Gy X-ray radiation. The cell apoptosis in each group was detected by flow cytometry. The radiosensitivity was evaluated by clone formation assay.@*Results@#The expression levels of USP28 and c-Myc in ECA109 were significantly higher than those in Het-1A (both P<0.05), and the expression levels of USP28 and c-Myc in ECA109R were remarkably higher than those in ECA109(both P<0.05). The pcDNA-USP28 and pcDNA-c-Myc recombinant plasmids were successfully constructed. Compared with the negative control group, the expression of USP28 at the protein and mRNA levels in the si-USP28 group was significantly down-regulated, whereas those in the pcDNA-USP28 group were remarkably up-regulated. Similar results were obtained in terms of c-Myc. Compared with the control group, the expression level of c-Myc protein was significantly up-regulated in the pcDNA-USP28 group, whereas considerably down-regulated in the si-USP28 group. After 6 Gy irradiation, the apoptosis rate and radiosensitivity of ECA109 cells were significantly declined. The apoptosis rate and radiosensitivity of ECA109R cells were increased in the si-USP28 group.@*Conclusions@#The expression of USP28 protein is closely correlated with the radiosensitivity of esophageal cancer cells. The underlying mechanism may be related to the regulation of c-Myc expression by USP28.
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Objective To evaluate the effect of RNF2 gene knockdown in ECA109 cells on the radiosensitivity to esophageal cancer cell xenograft in nude mice. Methods Thirty-six male BALB/c/nu nude mice were randomly divided into 6 groups: control group, control+ irradiation group, NC group, NC+irradiation group, RNF2 shRNA group and RNF2 shRNA+ irradiation group. The nude mouse models with transplanted tumors were established by subcutaneous inoculation of EAC109 cells and given with irradiation at a dose of 3 Gy for 5 times. The longest ( a) and shortest ( b) diameters of the transplanted tumor were measured every 2 to 3 day since the fourteenth day after inoculation. The time of tumor formation was recorded. The tumor volume was calculated according to the formula ( ab2/2 ) . The growth curve was delineated. Three nude mice were sacrificed in each group at 24 h after the initial irradiation. The expression of RNF2 at the mRNA and protein levels in transplanted tumor tissues was measured by qRT-PCR and immunohistochemistry, respectively. The growth and tumor volume of the other nude mice in each group were observed. The cell apoptosis of transplanted tumor tissues was detected by TUNEL assay. The expression of Bcl-2 and Bax at the mRNA and protein levels in transplantated tumor tissues was quantitatively measured by qRT-PCR and immunohistochemistry, respectively. Results The tumor growth rate was the highest in the control and NC groups. The knockdown of RNF2 reduced the growth rate of xenografts and the tumor growth rate was the slowest in the RNF2 shRNA+ irradiation group ( P<0.05) . TUNEL assay revealed that the cell apoptosis rates in all groups were significantly increased after irradiation ( all P<0.05) . Before and after irradiation, the apoptosis rate in the RNF2 shRNA group was markedly higher than those in the control and NC groups ( both P<0.05) . Prior to irradiation, the expression levels of RNF2 mRNA and protein in the RNF2 shRNA group were significantly lower compared with those in the control and NC groups ( all P<0.05) , and the tendency became more significant after irradiation. Compared with the control and NC groups, the expression levels of Bcl-2 mRNA and protein were significantly down-regulated in the RNF2 shRNA group before and after irradiation ( all P<0.05) , whereas those of Bax mRNA and protein were considerably up-regulated ( all P<0.05 ) . Conclusions In vivo experiment demonstrates that RNF2 knockdown effectively increases the radiosensitivity of esophageal carcinoma EAC109 cells in nude mouse models with transplanted tumors, which is intimately associated with inducing the cell apoptosis.
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Objective To examine the effect of X-ray radiotherapy on cell proliferation, migration, apoptosis, and cell cycle of human esophageal carcinoma ECA-109 cells following RNA interference (RNAi)-mediated downregulation of RNF2 gene expression.Methods The level of RNF2 mRNA expression in the human esophageal carcinoma cell line ECA-109 was determined using RT-PCR.Cell proliferation of ECA-109 was measured by MTT assay, and the changes in RNF2 protein expression in ECA-109-R cells were determined using Western blot.The changes in cell cycle and cell apoptosis at different time points following radiation were analyzed by flow cytometry, and the effect of transduction on cell migration was examined using Transwell migration assay.Data were subjected to an analysis of variance with repeated measurement design.Results The mean mRNA and protein levels of RNF2 in ECA-109 cells were significantly increased in a dose-dependent manner in the radiation group than in the control group (P0.05).The Transwell migration assay showed that the number of migrating cells following 3.5 h of radiation was significantly lower in the ECA-109-R group than in the ECA-109 and ECA-109-N groups (P<0.01).The percentage of G2/M phase cells in each group was significantly lower following 6 Gy radiation compared to that in the corresponding untreated group (P<0.01), and the percentage of G2/M phase cells was significantly lower in the ECA-109-R group than in the ECA-109 and ECA-109-N groups (P<0.05).Furthermore,cell apoptosis following radiation was also significantly higher in the ECA-109-R group than in the ECA-109 and ECA-109-N groups (P<0.01).Conclusions RNAi-mediated downregulation of RNF2 expression in esophageal carcinoma cells can reduce cell proliferation and cell migration, rescue post-radiation G2/M cell cycle arrest, promote cell apoptosis,and increase radiosensitivity.
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Objective To study the effects of adenosine triphosphate (ATP) on proliferation of human squamous esophageal carcinoma Eca-109 and hepatoma SMMC-7721 cells in vitro and the underlying mechanism. MethodsMTT assay was used to determine the proliferation of tumor cells. The AO/EB double stained cells were observed under fluorescence microscope. The effects of ATP on the cell cycle, apoptotic rate and apoptosis-related protein were detected by flow cytometry. Results ATP showed inhibitory effects on Eca-109 and SMMC-7721 cells at the concentration of 0.01～0.3 mmol/L. Exposure to 0.3 mmol/L ATP for 72 h, some of SMMC-7721 cells displayed morphological changes of apoptosis, but Eca-109 cells did not show the characteristics of apoptosis markedly. There was no significant change in the apoptotic rate and apoptosis-related protein of the two tumor cell lines treated with ATP 0.03, 0.1 and 0.3 mmol/L for 72 h respectively. The proportion of Eca-109 cells in G0/G1-phase of cellcycle was significantly increased, meanwhile the proportion of Eca-109 cells in S-phase and proliferation index value was significantly decreased by treatment with 0.3 mmol/L ATP. Conclusion ATP inhibited Eca-109 cell proliferation by changing the distribution of cell cycle phase, and its mechanism might not related to apoptosis, but for SMMC-7721 cell, the inhibition of cell proliferation induced by ATP was not related to the change in cell cycle.
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Objective To investigate the effects and possible mechanisms of ursolic acid (UA) on inhibiting proliferation of human esophageal carcinoma cell Eca-109 and inducing its apoptosis. Methods Cell proliferation was determined by MTT assay. Electron microscope was used to observe the ultrastructural changes of Eca-l09 induced by UA. Cell cycle and apoptotic rate were analyzed by flow cytometry (FCM),and the expression of P27kip1,Bcl-2 and Bax were detected by Western blot method. Results UA could significantly inhibit the growth of Eca-109 cells(P
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Objective To establish the cancer vaccine (EC109-DC) prepared by fusions of esophageal carcinoma cell line with dendritic cell derived from cord blood and study the biological characteristics and antitumor immunity.Methods CD 34 + hematopoietic stem cells were isolated from cord blood using CD 34 + Progenitor Cell Isolation Kit by magnetic cell sorting system (MACS);expended the cells as DC,and then fused with EC109 by PEG-3600;selected the fusion cells by MACS;observed the phenotypes and proliferation by flow cytometry and technique of cell culture in vitro. Lymphocytes proliferation reaction and the CTL cytotoxicity were examined with MTT.Results EC109-DC could proliferate slowly in vitro and highly expressed CD80,CD83 and CD86.Lymphocytes proliferation reaction and the specific cytotoxicity against EC109 induced by EC109-DC cells were significantly higher than the control groups (P