RESUMEN
Objective:To evaluate the effects of high mobility group protein box 1 (HMGB1) on clinical prognosis of esophagus squamous cell carcinoma (ESCC) patients treated with chemoradiotherapy and the radiosensitivity of xenograft in nude mice.Methods:A total of 90 endoscopic biopsy specimens were obtained from ESCC patients treated with chemoradiotherapy. The expression level of HMGB1 was determined by immunohistochemical staining. High expression level was defined when staining was observed on ≥50% of the tumor cells. All patients were divided into the high expression group ( n=48) and low expression group ( n=42), and their survival information was retrospectively analyzed. Cell transfection was performed with the plasmid carrying human HMGB1-shRNA to knockdown HMGB1 expression in ECA109 cells and xenograft mouse models were established. The tumor volume and mass were calculated after irradiation with a dose of 15 Gy. The cell apoptosis in xenograft tissues were detected. Survival analysis was performed using Kaplan-Meier method. Univariate prognostic analysis was conducted by log-rank test. Intergroup comparison was performed by analysis of variance (ANOVA). Results:The expression level of HMGB1 was significantly associated with gross tumor volume, longest diameter of tumor, T staging and distant metastasis ( χ2=9.663, 5.625, 4.068, 7.146, all P<0.05). In the low expression group, the overall survival (OS) ( χ2=4.826, P=0.028), progression-free survival (PFS) ( χ2=4.390, P=0.036) were longer compared with that in the high expression group. Further analysis of HMGB1-high expression patients showed that the radiation dose and the combination of chemoradiotherapy did not significantly affect the OS or PFS of ESCC patients. We observed that knockdown of HMGB1 slowed the growth rate of xenograft, decreased the tumor volume and increased the apoptosis rate after irradiation. Conclusions:ESCC patients with high expression level of HMGB1 obtain poor prognosis after chemoradiotherapy, which can be enhanced by increasing the sensitivity to radiotherapy and chemotherapy. HMGB1 knockdown can effectively increase the radiosensitivity of xenograft in ESCC nude mice.
RESUMEN
Objective:To examine the effect of FAM83D knockdown on proliferation, survival ability and invasion of human esophageal squamous cell carcinoma after X-ray radiation, and explore the mechanism.Methods:The expression of FAM83D, E-cadherin and vimentin in tumor tissues was detected in 69 cases of esophageal squamous cell cancer by using immunohistochemical method. The siRNA based on the sequences of the FAM83D mRNA were synthesized to transfect into the cultured ECA109 cells as FAM83D shRNA group. The effect of silencing FAM83D gene was evaluated to determine the protein levels of FAM83D in the human oesophageal squamous cell carcinoma ECA109 and KYSE30 cells using western blotting. MTS, clone formation, and Transwell assay were employed to examine the proliferation, survival ability and invasion of ECA109 and KYSE30 cells in vitro, respectively. We used flow cytometry assay to analyze distribution of cell apoptosis in different groups. Western blotting was used to examine the expression of cell metastasis-related molecules and apoptosis-related protein. Results:The strong expression rates of FAM83D, E-cadherin, and vimentin were 55%(38/69), 36%(25/69) and 61%(42/69) in the tumor tissues, respectively. FAM83D protein expression was significantly and negatively correlated with the expression of E-cadherin ( r=-0.350, P<0.01), and positively with the expression of vimentin ( r=0.470, P<0.01). Western blotting results demonstrated that silencing FAM83D gene significantly reduced the FAM83D protein expression ( P<0.01). MTS data demonstrated that FAM83D knockdown after irradiation significantly inhibited the proliferation of esophageal squamous cell carcinoma ECA109 and KYSE30 cells ( P<0.05). The data from the clone formation assay revealed that the radiosensitivity was increased after downragulation of FAM83D expression ( P<0.01). In addition, the invasive abilities of oesophageal carcinoma cells transfected with FAM83D shRNA after irradiation were significantly inhibited compared with those of the NC group ( P<0.01), followed by the downregulation of N-cadherin, vimentin, Snail, p-Akt and p-GSK-3β expression, and the upregulation of E-cadherin expression ( P<0.01). The apoptosis rate of tumor cells in FAM83D shRNA group after irradiation was markedly increased ( P<0.01), followed by a decrease of Bcl-2 and Mcl-1 expression and an increase of Cleaved caspase-3 expression ( P<0.01). Conclusions:FAM83D expressions was found to be closely related to the invasion and development of ESCC. Furthermore, siRNA interference technology inhibited the expression of FAM83D gene in oesophageal squamous cell carcinoma cells, reduced the proliferation, invasion of cells, induced cell apoptosis, and increased radiosensitivity, which may be associated with regulating the epithelial-mesenchymaltransition via Snail/Akt/GSK-3β signaling pathways.
RESUMEN
Objective@#To evaluate the effect of X-ray radiation on cell proliferation, migration, survival ability and cell cycle of human esophageal squamous cell carcinoma after RNA interference-mediated down-regulation of HMGB1 gene expression.@*Methods@#The expression of HMGB1 at mRNA and protein levels in the human esophageal squamous cell carcinoma cell lines ECA109 and KYSE30 was determined using RT-PCR and Western blot assays. MTS and Transwell assays were employed to examine the proliferation and migration of ECA109 and KYSE30 cell lines. The cellular survival ability in vitro was assessed by clone formation assay. The cell cycle after X-ray radiation in different groups was detected by flow cytometry.@*Results@#The expression of HMGB1 at mRNA and protein levels in ECA109 and KYSE30 cells were markedly higher in a dose-dependent and time-dependent manner in the radiation group than that in the control group (all P<0.05). MTS results demonstrated that the proliferation of ECA109 and KYSE30 cells was obviously lower at each time point after radiation than that in the group without radiation (all P<0.01). The expression of HMGB1 at mRNA and protein levels was significantly inhibited in the HMGB1 siRNA group than those in the control and NC groups (both P<0.01). The data from the clone formation assay revealed that the radiosensitivity was significantly increased after down-regulation of HMGB1 expression (P<0.01). Transwell migration assay revealed that the number of migrating cells at the fourth hour after X-ray irradiation in the HMGB1 siRNA group was significantly lower than those in the control and negative groups (both P<0.01). In the HMGB1 siRNA group, the percentage of cells at G0/G1 phase was obviously higher, whereas the percentage of S phase was significantly lower than those in the control and NC groups, and the trend was even more significant after X-ray radiation (all P<0.01).@*Conclusion@#Inhibition of HMGB1 expression by siRNA can suppress the proliferation and migration of ECA109 and KYSE30 cells and enhance the radiosensitivity by increasing the cell cycle arrest at G0/G1 stage after X-ray irradiation in vitro.
RESUMEN
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.
RESUMEN
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.
RESUMEN
Objective To investigate the effects of BMI-1 expression inhibition by RNA interference on the radiosensitivity of esophageal cancer TE-13 cells and its mechanism.Methods The siRNA based on the sequence of BMI-1 mRNA was synthesized to transfect cultured TE-13 cells as BMI-1 siRNA group,a negative one was synthesized to transfect cultured TE-13 cells as negative control group (NC group),and untransfected TE-13 cells were named as control group.The expression of the BMI-1 mRNA and protein in TE-13 cells was measured by quantitative real-time PCR and Western blot,respectively.The cell proliferation and the radiosensitivity of TE-13 cells were measured by MTS and colony-forming assay,respectively.Flow cytometry was used to analyze cell cycle and apoptosis.The expression of BCL-2 and BAX in TE-13 cells was measured by Western blot.Comparison between groups was made by analysis of variance.Results The BMI-1 siRNA group had significantly lower expression of BMI-1 mRNA and protein than the control group and the NC group (P=0.000,0.000).The proliferation of TE-13 cells in the BMI-1 siRNA group decreased significantly after irradiation (P=0.031).The colony-forming assay showed that the BMI-1 siRNA group had a significantly higher radiosensitivity than the control group and the NC group (P=0.000).After irradiation,the BMI-1 siRNA group had a significantly lower percentage of cells in G2/M phase than the control group and the NC group (P=0.000,0.000).The BMI-1 siRNA group had a significantly increased apoptosis rate (P=0.000,0.000),significantly reduced expression of BCL-2(P=0.000,0.000),and significantly increased expression of BAX after irradiation (P=0.000,0.000).Conclusions BMI-1 siRNA can inhibit the expression of BMI-1 gene in esophageal cancer TE-13 cells,eliminate the cell cycle arrest in G2/M phase,induce cell apoptosis after ionizing irradiation in vitro,and increase the radiosensitivity,which may be related to the regulation of the expression of BCL-2 and BAX.
RESUMEN
Background and purpose:B cell-specific MLV integration site 1 (BMI-1) gene plays an important role in DNA damage after exposure to irradiation. The present study aimed to investigate the effect ofBMI-1 on radio-sensitivity of esophageal carcinoma cell after down-regulation of BMI-1 expression by silencing siRNA.Methods:Three pairs of siRNA based on the sequences of the BMI-1 mRNA were synthesized (siRNA1, siRNA2 and siRNA3) by compa-ny, and transfected into cultured TE13 cells as the BMI-1 siRNA groups, and a negative one was synthesized to be used as the negative control (NC) group. The untransfected group was named as the control group. BMI-1 mRNA and protein expression in esophageal cancer TE13 cells were detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blot in different groups. This study used flow cytometry assay to analyze cell cycle of transfected cells, and examined cellular growth and radiosensitivityin vitro by MTT and clone formation assay. mRNA and protein expression of p16 and CDK4 in esophageal cancer TE13 cells were detected by RT-PCR and Western blot.Results:The results of RT-PCR and Western blot showed that the expressions of BMI-1 at gene and protein levels were inhibited after silencing the BMI-1 gene. The mRNA and protein expression of BMI-1 in BMI-1 siRNA3 group were both significantly lower than that in BMI-1 siRNA1 and 2 groups. There was no significant difference in the cell proliferation among control, NC and BMI-1 siRNA3 groups. The values ofD0,Dq, and SF2 in BMI-1 siRNA3 group were 1.761, 2.122 and 0.6255, respectively, obvi-ously lower than those in control group (2.514, 2.694 and 0.8268) and those in NC group (2.506, 2.664 and 0.8231), while the value of N in BMI-1 siRNA3 group (3.336) was higher than that in control group (2.92) and that in NC group (2.895), which showed higher radiosensitivity in BMI-1 siRNA3 group. In addition, the cell cycle was arrested at G2/M phase after irradiation in control and NC groups. The percentage of G0/G1 phase in BMI-1 siRNA3 group was higher than that of control group and NC group, while the percentage of G2/M phase was lower than those in the latter. The up-regulation of p16 and down-regulation of CDK4 at gene and protein levels were detected after knockdown of BMI-1 expression by siRNA (P<0.01).Conclusion:siRNA could inhibitBMI-1 gene expression in esophageal cancer TE13 cells and enhance radiosensitivity, followed by eliminating the cell cycle arrest at G2/M stage after irradiationin vitro, which is related to the regulation of the protein expression ofp16 andCDK4.