表没食子儿茶素没食子酸酯诱导人肝癌细胞HepG2凋亡与TGF-β1-Smad通路激活有关

Objective To investigate the cytotoxic effect of epigallocatechin gallate(EGCG)on human hepatocellular carcinoma cell line HepG2 cells and corresponding changes of TGF-β1-Smad pathway.Methods The cytotoxic effect of EGCG on HepG2 cells was determined by MTT assay.Cell cycle and apoptosis rate were detected by flow cytometry.RT-PCR and luciferase assay were used to verify whether TGF-β1-Smad signaling pathway is intact in HepG2.The mRNA expression of Smad 2,Smad3,Smad4 and Smad7 was detected by real-time PCR.Results EGCG induced apoptosis in the HepG2 ceils in a time-and concentration-dependent manner.The proportion of G1 phase cells was increased gradually as the concentration increased.However,the percentage of cells in S phase was decreased gradually.Annexin V/PI assay demonstrated that early apoptosis increased as the concentration increased,and late apoptosis also increased,when treated with high-concentration EGCG.The intact TGF-β1-Smad pathway was verified by luciferase assay and RT-PCR.There was no significant effect of EGCG on mRNA level of Smad 2,Smad 3,and Smad 4 in HepG2 cells,but downregulated mRNA level of Smad 7.Conclusion EGCG can reduce apoptosis in human hepatocellular carcinoma cell line HepG2 cells.The activation of TGF-β1-Smad signaling pathway may be involved in its cytotoxicity mechanisms.     

Sublethal Irradiation Promotes Migration and Invasiveness of Prostate Cancer PC-3 Cells：Implications for Radiotherapy of Human Prostate Cancer

OBJECTIVE To study the changes in the matrix metalloproteinases-2 and 9 （MMP2, MMP9） induced by ^60Co γ-ray external irradiation of human prostate cancer PC-3 cells. METHODS Human prostate cancer PC-3 cells were irradiated with different doses of ^60Co γ-rays. Cell migration and invasiveness were evaluated and the expression of MMP2, and MMP9 was investigated by RT-PCR, Western blotting and flow cytometry（FCM）. RESULTS Irradiation enchances invasive protential at the doses of 1,3 and 5 Gy,whereas it significantly inhibits cell migration. CONCLUSION The different doses of ^60Co γ-ray external irradiation for prostate cancer may have different effects through the changes of MMP2, and MMP9 expression.     

The inhibiting effects of Laggera alata flavone on human ovarian cancer HO-8910 cells proliferation and its mechanism in vitro

The purpose of this study was to investigate the effect of Laggera alata flavonen （LAF） on the inhibit- ing effect of human ovarian cancer HO-8910 cells proliferation and its possible mechanism in vitro. Methods： Human ovarian cancer HO-8910 cells were cultured in vitro. Inhibitory effect of LAF on the viability of HO-8910 cells was evaluated by the MTT assay. Apoptotic effect of different concentrations of LAF on HO-8910 cells was assessed by AO/EB staining and FCM with propidium iodide （PI） staining. Expression of proteins related to apoptosis was analyzed by Western blot. Results： LAF significantly inhibited the viability of HO-8910 cells proliferation in a dose-dependent and time-dependent manner, there were statistical significance compared with NS group （P 〈 0.05）, and the ICso was 4.28 pg/mL for 48 h. The cells treated with LAF showed typical morphological change and apoptotic rate increased by FCM in a dose-dependent, and there was notable dif- ference compared with NS group （P 〈 0.05）. Western blot showed that expression of Fas, caspase-8, tBid and Cyto-c proteins were up-regulated after treatment with LAF for 48 h in a concentration dependent. Conclusion： LAF could inhibit HO-8910 cells proliferation and induce apoptosis, which may be through the pathway of death receptor in vitro.     

黏蛋白-1和细胞角蛋白-20在食管癌中的表达及意义

Objective To investigate the expressions and clinical significances of MUC1-mRNA and CK20-mRNA in peripheral blood of esophageal cancer patients.Methods MUC1-mRNA and CK20-mRNA were detected in 53 patients with esophageal cancer,10 patients with esophageal benign tumor and 20 healthy volunteers by RT-PCR technique.Results The expressions of MUC1-mRNA,CK20-mRNA and combining group were 35.85 % (19/53),49.06 % (26/53) and 62.26 % (36/53) in peripheral blood of 53 esophageal cancer patients.In control group,there was no expression of MUC1-mRNA and CK20-mRNA in peripheral blood of 10 patients with benign esophageal disease and 20 healthy volunteers.The positive rate increased by combining test(x2 =11.0228,P ＜0.05).Conclusion MUC1-mRNA and CK20-mRNA might be specific and sensitive markers to detect circulating tumor cells in peripheral blood and their expressions are closely related to TNM stages of the esophageal cancer patients.The combining test might be of high value of the diagnosis of micrometastasis.     

黏蛋白-1和细胞角蛋白-20在食管癌中的表达及意义

Objective To investigate the expressions and clinical significances of MUC1-mRNA and CK20-mRNA in peripheral blood of esophageal cancer patients.Methods MUC1-mRNA and CK20-mRNA were detected in 53 patients with esophageal cancer,10 patients with esophageal benign tumor and 20 healthy volunteers by RT-PCR technique.Results The expressions of MUC1-mRNA,CK20-mRNA and combining group were 35.85 % (19/53),49.06 % (26/53) and 62.26 % (36/53) in peripheral blood of 53 esophageal cancer patients.In control group,there was no expression of MUC1-mRNA and CK20-mRNA in peripheral blood of 10 patients with benign esophageal disease and 20 healthy volunteers.The positive rate increased by combining test(x2 =11.0228,P ＜0.05).Conclusion MUC1-mRNA and CK20-mRNA might be specific and sensitive markers to detect circulating tumor cells in peripheral blood and their expressions are closely related to TNM stages of the esophageal cancer patients.The combining test might be of high value of the diagnosis of micrometastasis.     

DJ-1 promotes proliferation and epithelial-mesenchymal transition of colorectal cancer cells by regulating p53 signaling pathway北大核心CSCD

Objective: To investigate the effects of up-regulating or silencing DJ-1 gene expression on the apoptosis, migration and invasion of colorectal cancer (CRC), and to explore the possible molecular mechanism. Methods: The expression level of DJ-1 in CRC tissues and cells was detected by immunohistochemistry, Western blotting and real-time fluorescent quantitative PCR, respectively. The SW480 and HCT116 cells were transfected with the recombinant lentiviral vector carrying human DJ-1 gene to obtain DJ-1 overexpressed SW480/OE-DJ-1 and HCT116/OE-DJ-1 cells, while the cells transfected with the empty vector was as the negative control (OE-NC). The SW480 and HCT116 cells were transfected with the recombinant lentiviral vector carrying the specific shRNA targeting DJ-1 gene to generate the SW480/shDJ-1 and HCT116/sh-DJ-1 cells with stable knockdown of DJ-1, while the cells transfected with the empty vector was as the negative control (sh-NC). Subsequently, the expressions of DJ-1 and p53 protein and mRNA were detected by immunohistochemistry and real-time fluorescent quantitative PCR, respectively; and their relationship was analyzed. The expressions of p53 and its downstream apoptosis-related proteins Bax and Bcl-2 in SW480 and HCT116 cells with DJ-1 over-expression or knockdown were detected by Western blotting. The effects of overexpressing and silencing DJ-1 gene expression on the invasion and migration abilities of SW480 and HCT116 cells were detected by Transwell chamber assay. The epithelial-mesenchymal transition (EMT) of CRC cells was induced by transforming growth factor-β1 (TGF-β1), then the expression levels of DJ-1 and EMT-related markers (N-cadherin, β-catenin, vimentin, E-cadherin) were analyzed by Western blotting. Results: DJ-1 was highly expressed in 34 CRC tissues (24/34, 70.59%) (P < 0.001). The overall survival time of the patients with DJ-1 high expression was significantly shorter than that of the patients with DJ-1 low expression (P < 0.001). The high expression of DJ-1 was correlated with TNM stage, tumor location, lymph node metastasis, and degree of differentiation (all P < 0.05). There was a negative correlation between DJ-1 and p53 expressions (r =-0.428, P = 0.015). Silencing DJ-1 increased the expression level of p53 and its downstream apoptotic protein Bax, decreased the expression of anti-apoptotic protein Bcl-2 (all P < 0.05), and decreased the invasion and migration capacities of SW480 and HCT116 cells (both P < 0.01); Conversely, overexpressing DJ-1 decreased the expression level of p53 and Bax, increased the expression of Bcl-2 (all P < 0.05), and increased the invasion and migration capacities of SW480 and HCT116 cells (both P < 0.01). Overexpression of DJ-1 induced by TGF-β1 increased the expressions of N-cadherin, β-catenin and vimentin, and decreased the expression of E-cadherin in the process of EMT (P < 0.05). Conclusion: DJ-1 promotes the apoptosis and invasion of CRC cells by negatively regulating the p53 signaling pathway. © 2019 by TUMOR All rights reserved.     

TIME- AND DOSE-DEPENDENT UP-REGULATION OF TNF-α mRNA AFTER IRRADIATION OF HUMAN NSCLC CELL LINES IN VITRO

Objective： Even though radiotherapy plays a major role in the local treatment of non-small cell lung cancer （NSCLC）, little is known about the molecular effects of irradiation in this tumor. In the present study, we examined two NSCLC cell lines for their endogenous production of TNF-α after irradiation. To investigate the radiation-induced TNF-α production in NSCLC cell lines. Methods： Two human NSCLC cell lines （A549： squamous; NCI-H596： adenosquamous） were investigated for their TNF-α mRNA （real-time RT-PCR） after exposure to different irradiation doses （2, 5, 10, 20, 30, 40 Gy） and time intervals （1, 3, 6, 12, 24, 48 or 72 h）. The TNF-α mRNA expression was quantified by real-time RT-PCR. The clonogenic survival was evaluated after irradiation with 2, 4, 6 and 8 Gy. Results： Non-irradiated NSCLC cells exhibited no or very low TNF-α expression. For the NCI-H596 cell line, TNF-α expression was significantly elevated 1～12 h （maximum 6h： 568fold increase relative to unirradiated cells） in a time-dependent manner. The radiation-induced increase could be observed after irradiation with 2 Gy reaching maximal at 40 Gy, with 83 times higher than normal controls. The clonogenic survival of these cell lines was nearly identical. Conclusion： NCI-H596 cells produce significant quantities of TNF-α following irradiation in a time- and dose-dependent manner. The pro-inflammatory cytokine TNF-α is a key mediator for the pathogenesis of radiation pneumonitis. Radiation-induced endogenous TNF-α expression in NSCLC cells may affect the normal lung adjacent to the tumor and may be associated with an adverse clinical outcome of the patient.     

荜茇明碱诱导乳腺癌MDA-MB-231细胞凋亡的实验研究(英文)

Objective: The aim of the study was to investigate the apoptosis induced by piperlongumine on human breast adenoma MDA-MB-231 cells and the mechanism involved. Methods: Human breast adenoma MDA-MB-231 cells line was cultured in vitro. The inhibitory effect of piperlongumine on the proliferation of human breast adenoma MDA-MB-231 cells was measured by CCK-8 assay. Distribution of cell cycle was analyzed by flow cytometry. The apoptosis rates of MDA-MB-231 cells were measured using Annexin V/PI staining. The flow cytometry with the probe of DCFH-DA was used to detect the intracellular reactive oxygen species levels. Western blot was used to explore the protein expression of Bcl-2 and Bax. Results: The CCK-8 assay showed that piperlongumine had an inhibiting effect on the proliferation of MDA-MB-231 cells in a concentrationand time-dependent manner. MDA-MB-231 cells were markedly arrested at G0/G1 phase after treatment of piperlongumine. Piperlongumine induced apoptosis of MDA-MB-231 cells obviously. The level of intracellular reactive oxygen species was increased in a dose-dependent manner. The antioxidant N-acetyl-L-cystein inhibited the apoptosis of cells and the level of intracellular reactive oxygen species was also decreased. By Western blot analysis, we found the expression of Bax was up-regulated whereas that of Bcl-2 was down-regulated in a concentration-dependent manner. Conclusion: Piper-longumine possesses a significant function for inhibiting proliferation, arresting cells at G0/G1 phase and inducing apoptosis of MDA-MB-231 cells, which seems to be associated with the increased generation of intracellular reactive oxygen species as well as the down-regulation of Bcl-2 and up-regulation of Bax.     

模拟调强技术照射鼻咽低分化鳞癌细胞的生物效应机制研究

Objective To study the altered radiobiological effect of simulative intensity-modulated radiotherapy (SIMR) in cultured human nasopharyngeal carcinoma (NPC) cells and the related mechanism. Methods Single cell suspension of exponentially growing CNE-2 cells, a poor differentiated NPC cell line, was seeded and cultured for 12 hours, then the cells were irradiated in two different models by 6 MV X-ray beams at 3 Gy/min. In single fraction irradiation (SFR) model, cells were irradiated a single fraction of 0, 2, 4, 6 or 8 Gy within 0 to 3 minutes. In S1MR model, cells were irradiated 0, 2, 4, 6 or 8 Gy in 5 frac-tions with interval of 8.0-8.5 minutes between. Clonogenic assay was performed to determine the radiosen-sitivity. Cellular apoptosis was measured by flow cytometry. RT-PCR was used to detect mRNA expressions of Bax and Bcl-2, Respectively. Results Compared with SFR group, the survival fraction in SIMR group was higher at all the dose levels. The values of α, β, D0 and Dq were higher in SIMR group than in SFR group. At dose levels of 2 Gy, 4 Gy and 6 Gy, The early and late apoptotic cells in SIMR group were lower than in SFR group (21.20%: 15.89%, F=18.51, P=0.020;13.00%: 10.20, F=15.67, P=0.040).The mRNA expression of Bax was upregulated in a dose-dependent manner in the both groups. Compared with SFR group, the mRNA expression of Bax in SIMR group was lower at all the dose levels (Mean value of 76.75% : 62.50%, F =36.57, P =0.000). Bcl-2 mRNA expression at every dose level had no significant difference between the two groups (Mean value of 29.25% : 29.75%, F=0.74, P=0.800). Conclusions Prolonged delivery time in SIMR model can decrease the radiobiological effects.     

模拟调强技术照射鼻咽低分化鳞癌细胞的生物效应机制研究

Objective To study the altered radiobiological effect of simulative intensity-modulated radiotherapy (SIMR) in cultured human nasopharyngeal carcinoma (NPC) cells and the related mechanism. Methods Single cell suspension of exponentially growing CNE-2 cells, a poor differentiated NPC cell line, was seeded and cultured for 12 hours, then the cells were irradiated in two different models by 6 MV X-ray beams at 3 Gy/min. In single fraction irradiation (SFR) model, cells were irradiated a single fraction of 0, 2, 4, 6 or 8 Gy within 0 to 3 minutes. In S1MR model, cells were irradiated 0, 2, 4, 6 or 8 Gy in 5 frac-tions with interval of 8.0-8.5 minutes between. Clonogenic assay was performed to determine the radiosen-sitivity. Cellular apoptosis was measured by flow cytometry. RT-PCR was used to detect mRNA expressions of Bax and Bcl-2, Respectively. Results Compared with SFR group, the survival fraction in SIMR group was higher at all the dose levels. The values of α, β, D0 and Dq were higher in SIMR group than in SFR group. At dose levels of 2 Gy, 4 Gy and 6 Gy, The early and late apoptotic cells in SIMR group were lower than in SFR group (21.20%: 15.89%, F=18.51, P=0.020;13.00%: 10.20, F=15.67, P=0.040).The mRNA expression of Bax was upregulated in a dose-dependent manner in the both groups. Compared with SFR group, the mRNA expression of Bax in SIMR group was lower at all the dose levels (Mean value of 76.75% : 62.50%, F =36.57, P =0.000). Bcl-2 mRNA expression at every dose level had no significant difference between the two groups (Mean value of 29.25% : 29.75%, F=0.74, P=0.800). Conclusions Prolonged delivery time in SIMR model can decrease the radiobiological effects.     

模拟调强技术照射鼻咽低分化鳞癌细胞的生物效应机制研究

Objective To study the altered radiobiological effect of simulative intensity-modulated radiotherapy (SIMR) in cultured human nasopharyngeal carcinoma (NPC) cells and the related mechanism. Methods Single cell suspension of exponentially growing CNE-2 cells, a poor differentiated NPC cell line, was seeded and cultured for 12 hours, then the cells were irradiated in two different models by 6 MV X-ray beams at 3 Gy/min. In single fraction irradiation (SFR) model, cells were irradiated a single fraction of 0, 2, 4, 6 or 8 Gy within 0 to 3 minutes. In S1MR model, cells were irradiated 0, 2, 4, 6 or 8 Gy in 5 frac-tions with interval of 8.0-8.5 minutes between. Clonogenic assay was performed to determine the radiosen-sitivity. Cellular apoptosis was measured by flow cytometry. RT-PCR was used to detect mRNA expressions of Bax and Bcl-2, Respectively. Results Compared with SFR group, the survival fraction in SIMR group was higher at all the dose levels. The values of α, β, D0 and Dq were higher in SIMR group than in SFR group. At dose levels of 2 Gy, 4 Gy and 6 Gy, The early and late apoptotic cells in SIMR group were lower than in SFR group (21.20%: 15.89%, F=18.51, P=0.020;13.00%: 10.20, F=15.67, P=0.040).The mRNA expression of Bax was upregulated in a dose-dependent manner in the both groups. Compared with SFR group, the mRNA expression of Bax in SIMR group was lower at all the dose levels (Mean value of 76.75% : 62.50%, F =36.57, P =0.000). Bcl-2 mRNA expression at every dose level had no significant difference between the two groups (Mean value of 29.25% : 29.75%, F=0.74, P=0.800). Conclusions Prolonged delivery time in SIMR model can decrease the radiobiological effects.     

模拟调强技术照射鼻咽低分化鳞癌细胞的生物效应机制研究

Objective To study the altered radiobiological effect of simulative intensity-modulated radiotherapy (SIMR) in cultured human nasopharyngeal carcinoma (NPC) cells and the related mechanism. Methods Single cell suspension of exponentially growing CNE-2 cells, a poor differentiated NPC cell line, was seeded and cultured for 12 hours, then the cells were irradiated in two different models by 6 MV X-ray beams at 3 Gy/min. In single fraction irradiation (SFR) model, cells were irradiated a single fraction of 0, 2, 4, 6 or 8 Gy within 0 to 3 minutes. In S1MR model, cells were irradiated 0, 2, 4, 6 or 8 Gy in 5 frac-tions with interval of 8.0-8.5 minutes between. Clonogenic assay was performed to determine the radiosen-sitivity. Cellular apoptosis was measured by flow cytometry. RT-PCR was used to detect mRNA expressions of Bax and Bcl-2, Respectively. Results Compared with SFR group, the survival fraction in SIMR group was higher at all the dose levels. The values of α, β, D0 and Dq were higher in SIMR group than in SFR group. At dose levels of 2 Gy, 4 Gy and 6 Gy, The early and late apoptotic cells in SIMR group were lower than in SFR group (21.20%: 15.89%, F=18.51, P=0.020;13.00%: 10.20, F=15.67, P=0.040).The mRNA expression of Bax was upregulated in a dose-dependent manner in the both groups. Compared with SFR group, the mRNA expression of Bax in SIMR group was lower at all the dose levels (Mean value of 76.75% : 62.50%, F =36.57, P =0.000). Bcl-2 mRNA expression at every dose level had no significant difference between the two groups (Mean value of 29.25% : 29.75%, F=0.74, P=0.800). Conclusions Prolonged delivery time in SIMR model can decrease the radiobiological effects.     

模拟调强技术照射鼻咽低分化鳞癌细胞的生物效应机制研究

Objective To study the altered radiobiological effect of simulative intensity-modulated radiotherapy (SIMR) in cultured human nasopharyngeal carcinoma (NPC) cells and the related mechanism. Methods Single cell suspension of exponentially growing CNE-2 cells, a poor differentiated NPC cell line, was seeded and cultured for 12 hours, then the cells were irradiated in two different models by 6 MV X-ray beams at 3 Gy/min. In single fraction irradiation (SFR) model, cells were irradiated a single fraction of 0, 2, 4, 6 or 8 Gy within 0 to 3 minutes. In S1MR model, cells were irradiated 0, 2, 4, 6 or 8 Gy in 5 frac-tions with interval of 8.0-8.5 minutes between. Clonogenic assay was performed to determine the radiosen-sitivity. Cellular apoptosis was measured by flow cytometry. RT-PCR was used to detect mRNA expressions of Bax and Bcl-2, Respectively. Results Compared with SFR group, the survival fraction in SIMR group was higher at all the dose levels. The values of α, β, D0 and Dq were higher in SIMR group than in SFR group. At dose levels of 2 Gy, 4 Gy and 6 Gy, The early and late apoptotic cells in SIMR group were lower than in SFR group (21.20%: 15.89%, F=18.51, P=0.020;13.00%: 10.20, F=15.67, P=0.040).The mRNA expression of Bax was upregulated in a dose-dependent manner in the both groups. Compared with SFR group, the mRNA expression of Bax in SIMR group was lower at all the dose levels (Mean value of 76.75% : 62.50%, F =36.57, P =0.000). Bcl-2 mRNA expression at every dose level had no significant difference between the two groups (Mean value of 29.25% : 29.75%, F=0.74, P=0.800). Conclusions Prolonged delivery time in SIMR model can decrease the radiobiological effects.     

模拟调强技术照射鼻咽低分化鳞癌细胞的生物效应机制研究

Objective To study the altered radiobiological effect of simulative intensity-modulated radiotherapy (SIMR) in cultured human nasopharyngeal carcinoma (NPC) cells and the related mechanism. Methods Single cell suspension of exponentially growing CNE-2 cells, a poor differentiated NPC cell line, was seeded and cultured for 12 hours, then the cells were irradiated in two different models by 6 MV X-ray beams at 3 Gy/min. In single fraction irradiation (SFR) model, cells were irradiated a single fraction of 0, 2, 4, 6 or 8 Gy within 0 to 3 minutes. In S1MR model, cells were irradiated 0, 2, 4, 6 or 8 Gy in 5 frac-tions with interval of 8.0-8.5 minutes between. Clonogenic assay was performed to determine the radiosen-sitivity. Cellular apoptosis was measured by flow cytometry. RT-PCR was used to detect mRNA expressions of Bax and Bcl-2, Respectively. Results Compared with SFR group, the survival fraction in SIMR group was higher at all the dose levels. The values of α, β, D0 and Dq were higher in SIMR group than in SFR group. At dose levels of 2 Gy, 4 Gy and 6 Gy, The early and late apoptotic cells in SIMR group were lower than in SFR group (21.20%: 15.89%, F=18.51, P=0.020;13.00%: 10.20, F=15.67, P=0.040).The mRNA expression of Bax was upregulated in a dose-dependent manner in the both groups. Compared with SFR group, the mRNA expression of Bax in SIMR group was lower at all the dose levels (Mean value of 76.75% : 62.50%, F =36.57, P =0.000). Bcl-2 mRNA expression at every dose level had no significant difference between the two groups (Mean value of 29.25% : 29.75%, F=0.74, P=0.800). Conclusions Prolonged delivery time in SIMR model can decrease the radiobiological effects.     

模拟调强技术照射鼻咽低分化鳞癌细胞的生物效应机制研究

Objective To study the altered radiobiological effect of simulative intensity-modulated radiotherapy (SIMR) in cultured human nasopharyngeal carcinoma (NPC) cells and the related mechanism. Methods Single cell suspension of exponentially growing CNE-2 cells, a poor differentiated NPC cell line, was seeded and cultured for 12 hours, then the cells were irradiated in two different models by 6 MV X-ray beams at 3 Gy/min. In single fraction irradiation (SFR) model, cells were irradiated a single fraction of 0, 2, 4, 6 or 8 Gy within 0 to 3 minutes. In S1MR model, cells were irradiated 0, 2, 4, 6 or 8 Gy in 5 frac-tions with interval of 8.0-8.5 minutes between. Clonogenic assay was performed to determine the radiosen-sitivity. Cellular apoptosis was measured by flow cytometry. RT-PCR was used to detect mRNA expressions of Bax and Bcl-2, Respectively. Results Compared with SFR group, the survival fraction in SIMR group was higher at all the dose levels. The values of α, β, D0 and Dq were higher in SIMR group than in SFR group. At dose levels of 2 Gy, 4 Gy and 6 Gy, The early and late apoptotic cells in SIMR group were lower than in SFR group (21.20%: 15.89%, F=18.51, P=0.020;13.00%: 10.20, F=15.67, P=0.040).The mRNA expression of Bax was upregulated in a dose-dependent manner in the both groups. Compared with SFR group, the mRNA expression of Bax in SIMR group was lower at all the dose levels (Mean value of 76.75% : 62.50%, F =36.57, P =0.000). Bcl-2 mRNA expression at every dose level had no significant difference between the two groups (Mean value of 29.25% : 29.75%, F=0.74, P=0.800). Conclusions Prolonged delivery time in SIMR model can decrease the radiobiological effects.     

模拟调强技术照射鼻咽低分化鳞癌细胞的生物效应机制研究

Objective To study the altered radiobiological effect of simulative intensity-modulated radiotherapy (SIMR) in cultured human nasopharyngeal carcinoma (NPC) cells and the related mechanism. Methods Single cell suspension of exponentially growing CNE-2 cells, a poor differentiated NPC cell line, was seeded and cultured for 12 hours, then the cells were irradiated in two different models by 6 MV X-ray beams at 3 Gy/min. In single fraction irradiation (SFR) model, cells were irradiated a single fraction of 0, 2, 4, 6 or 8 Gy within 0 to 3 minutes. In S1MR model, cells were irradiated 0, 2, 4, 6 or 8 Gy in 5 frac-tions with interval of 8.0-8.5 minutes between. Clonogenic assay was performed to determine the radiosen-sitivity. Cellular apoptosis was measured by flow cytometry. RT-PCR was used to detect mRNA expressions of Bax and Bcl-2, Respectively. Results Compared with SFR group, the survival fraction in SIMR group was higher at all the dose levels. The values of α, β, D0 and Dq were higher in SIMR group than in SFR group. At dose levels of 2 Gy, 4 Gy and 6 Gy, The early and late apoptotic cells in SIMR group were lower than in SFR group (21.20%: 15.89%, F=18.51, P=0.020;13.00%: 10.20, F=15.67, P=0.040).The mRNA expression of Bax was upregulated in a dose-dependent manner in the both groups. Compared with SFR group, the mRNA expression of Bax in SIMR group was lower at all the dose levels (Mean value of 76.75% : 62.50%, F =36.57, P =0.000). Bcl-2 mRNA expression at every dose level had no significant difference between the two groups (Mean value of 29.25% : 29.75%, F=0.74, P=0.800). Conclusions Prolonged delivery time in SIMR model can decrease the radiobiological effects.     

模拟调强技术照射鼻咽低分化鳞癌细胞的生物效应机制研究

Objective To study the altered radiobiological effect of simulative intensity-modulated radiotherapy (SIMR) in cultured human nasopharyngeal carcinoma (NPC) cells and the related mechanism. Methods Single cell suspension of exponentially growing CNE-2 cells, a poor differentiated NPC cell line, was seeded and cultured for 12 hours, then the cells were irradiated in two different models by 6 MV X-ray beams at 3 Gy/min. In single fraction irradiation (SFR) model, cells were irradiated a single fraction of 0, 2, 4, 6 or 8 Gy within 0 to 3 minutes. In S1MR model, cells were irradiated 0, 2, 4, 6 or 8 Gy in 5 frac-tions with interval of 8.0-8.5 minutes between. Clonogenic assay was performed to determine the radiosen-sitivity. Cellular apoptosis was measured by flow cytometry. RT-PCR was used to detect mRNA expressions of Bax and Bcl-2, Respectively. Results Compared with SFR group, the survival fraction in SIMR group was higher at all the dose levels. The values of α, β, D0 and Dq were higher in SIMR group than in SFR group. At dose levels of 2 Gy, 4 Gy and 6 Gy, The early and late apoptotic cells in SIMR group were lower than in SFR group (21.20%: 15.89%, F=18.51, P=0.020;13.00%: 10.20, F=15.67, P=0.040).The mRNA expression of Bax was upregulated in a dose-dependent manner in the both groups. Compared with SFR group, the mRNA expression of Bax in SIMR group was lower at all the dose levels (Mean value of 76.75% : 62.50%, F =36.57, P =0.000). Bcl-2 mRNA expression at every dose level had no significant difference between the two groups (Mean value of 29.25% : 29.75%, F=0.74, P=0.800). Conclusions Prolonged delivery time in SIMR model can decrease the radiobiological effects.     

模拟调强技术照射鼻咽低分化鳞癌细胞的生物效应机制研究

Objective To study the altered radiobiological effect of simulative intensity-modulated radiotherapy (SIMR) in cultured human nasopharyngeal carcinoma (NPC) cells and the related mechanism. Methods Single cell suspension of exponentially growing CNE-2 cells, a poor differentiated NPC cell line, was seeded and cultured for 12 hours, then the cells were irradiated in two different models by 6 MV X-ray beams at 3 Gy/min. In single fraction irradiation (SFR) model, cells were irradiated a single fraction of 0, 2, 4, 6 or 8 Gy within 0 to 3 minutes. In S1MR model, cells were irradiated 0, 2, 4, 6 or 8 Gy in 5 frac-tions with interval of 8.0-8.5 minutes between. Clonogenic assay was performed to determine the radiosen-sitivity. Cellular apoptosis was measured by flow cytometry. RT-PCR was used to detect mRNA expressions of Bax and Bcl-2, Respectively. Results Compared with SFR group, the survival fraction in SIMR group was higher at all the dose levels. The values of α, β, D0 and Dq were higher in SIMR group than in SFR group. At dose levels of 2 Gy, 4 Gy and 6 Gy, The early and late apoptotic cells in SIMR group were lower than in SFR group (21.20%: 15.89%, F=18.51, P=0.020;13.00%: 10.20, F=15.67, P=0.040).The mRNA expression of Bax was upregulated in a dose-dependent manner in the both groups. Compared with SFR group, the mRNA expression of Bax in SIMR group was lower at all the dose levels (Mean value of 76.75% : 62.50%, F =36.57, P =0.000). Bcl-2 mRNA expression at every dose level had no significant difference between the two groups (Mean value of 29.25% : 29.75%, F=0.74, P=0.800). Conclusions Prolonged delivery time in SIMR model can decrease the radiobiological effects.