الملخص
Objective To explore the effect of radiosurgery in combination of temozolomide therapy in vitro and in vivo on invasion and endocrine function of human glioma cell line U87-epidermal growth factor receptor and variant Ⅲ (EGFRvⅢ) and their xenografl.Methods (1) Human glioma U87-EGFRvⅢ cells were routinely cultured;CCK-8 was used to detect the effect of temozolomide at different concentrations on proliferation of U87-EGFRvⅢ cells,and the semi-inhibitory concentration (IC50) oftemozolomide was calculated;the U87-EGFRvⅢ cells were divided into control group,6 Gy radiotherapy group and 12 Gy radiotherapy group,and the expressions of invasion-related proteins and gene repair proteins in the three groups were detected by Western blotting after 0,6 and 12 Gy edge-dose irradiation,respectively;the U87-EGFRvⅢ cells were divided into control group,6 Gy radiotherapy group and 6 Gy radiation combined with temozolomide treatment group (5 mmol/L temozolomide was added after 6 Gy irradiation),and 24 h after each treatment,Western blotting was used to detect the expressions of invasion related proteins and gene repair related proteins in the three groups.(2) Nude mouse transplantation intracranial glioma models were established with cell suspension of the control group,6 Gy radiotherapy group and 6 Gy radiation combined with temozolomide treatment group;7,14,21 d after transplantation,biolumineseence imaging (BLI) was employed to detect luciferase expression in nude micein vivo and measurement of transplanted tumors was performed;survival curve and body mass curve were drew in nude mice;immunohistochemical staining was used to detect the expressions of EGFRvⅢ,epidermal growth factor receptor (EGFR),matrix metalloproteinase (MMP)-9,vascular endothelial growth factor (VEGF) and Ki67 in intracranial transplanted gliomas.Results (1) The IC50 oftemozolomide on U87-EGFRvⅢ cells was 5 mmol/L;as compared with those in the control group,the expressions of EGFRvⅢ,EGFR,MMP-2,MMP-9,VEGF,MGMT,AKT-1,β-catenin and Ku70 significantly increased in the cells of the 6 Gy radiotherapy group,while the expressions of EGFRvⅢ,EGFR,MMP-2,MMP-9,VEGF,MGMT,AKT-1,β-catenin and Ku70 significantly decreased in the cells of the 12 Gy radiotherapy group as compared with those in the 6 Gy radiotherapy group (P＜0.05);as compared with those in the 6 Gy radiotherapy group,the expressions of EGFRvⅢ,EGFR,MMP-2,MMP-9,VEGF,MGMT,AKT-1,β-catenin and Ku70 in cells of the 6 Gy radiotherapy combined with temozolomide group were statistically decreased (P＜0.05).(2) As compared with mice in the control group and 6 Gy radiotherapy group,mice in the 6 Gy radiotherapy combined with temozolomide group had significantly lower cell tumorigenicity,significantly higher survival rate and body mass 21 d after transplantation,and significantly smaller volume of xenograft tumors (P＜0.05);the expressions of EGFRvⅢ,EGFR,MMP-9,VEGF and Ki67 in tumor tissues of nude mice in the 6 Gy radiotherapy group were significantly decreased as compared with those in the control group;as compared with those in the 6 Gy radiotherapy group,the expressions of EGFRvⅢ,EGFR,MMP-9,VEGF and Ki67 in tumor tissues of mice in the 6 Gy radiotherapy group were significantly decreased (P＜0.05).Conclusion The combined treatment of radiosurgery and temozolomide can more obviously inhibit the invasiveness of U87-EGFRvⅢ cells and it exerts a stronger inhibitory effect on tumorigenicity of U87-EGFRvⅢ cells in brain of nude rats.
الملخص
Objective To investigate the effect of PM2.5 airborne particulate matter with a mean diameter of less than 2.5μm exposure on autophagy and explore the links between autophagy and apoptosis in human lung cancer cells(A549). Methods A549 cells were exposed to 100μg/mL PM2.5 with or without 3-MA(autophagy inhibitor)for various periods of 0、2、4、12 or 24 hrs. Autophagy in A549 cells was assessed by determining the lev-el of LC3(a known autophagy marker)using confocal microscopy. The level of microtubule-associated protein 1 light chain 3(LC3) Ⅱ conversion and Bax (a pro-apoptotic protein) was detected by western blotting. Results The expression of LC3 and the ratio of LC3-II/LC3-I in A549 cells was significantly increased and Bax was signifi-cantly decreased following exposure to PM2.5100 μg/mL for 24 h in a time-dependent manner(P < 0.05). After treated with 100 μg/mL PM2.5,the formation of LC3 in A549 cells as evidenced by the intensity of intracellular fluorescence was significantly increased ,and autophageosomes were observed around nucleus in A549 cells. Fur-thermore blockage of autophagy by 3-MA led to a significant increase in the pro-apoptotic protein Bax. Conclu-sion PM2.5 exposure induces autophagy which may protect against apoptosis induced by PM2.5 in A549 cells.
الملخص
Objective To research the effect of radiosurgery in combination of temozolomide therapy in vitro on invasion and endocrine function of rat pituitary adenoma cells.Methods Rat pituitary adenoma cell lines GH3 and MMQ were divided into control group,10 Gy irradiation group,20 Gy irradiation group,temozolomide treatment group,and radiosurgery in combination of temozolomide group;cells without exposure were used as control group,cells treated with gamma knife radiation respectively with marginal doses of 10 and 20 Gy (all to the 99％ isodose line) were used as 10 Gy irradiation group and 20 Gy irradiation group,cells treated with 250 μmol/L and 615 μmol/L temozolomide for 24 h after 20 Gy radiation were used as radiosurgery in combination of temozolomide group,and cells treated with 250 μmol/L and 615 μmol/L temozolomide for 24 h were used as temozolomide treatment group.Real time-PCR and Western blotting were employed to measure the mRNA and protein expressions of matrix metalloproteinase (MMP)-9 and vascular endothelial growth factor (VEGF);and secretion of prolactin (PRL) and growth hormone (GH) was detected by ELISA.Results As compared with the control group,the 10 Gy irradiation group and 20 Gy irradiation group had significantly lower mRNA and protein expressions of MMP-9 and VEGF,and secretion of PRL and GH (P＜0.05);and these levels in the 20 Gy irradiation group were significantly lower than those in the 10 Gy irradiation group (P＜0.05);As compared with the 10 Gy irradiation group,20 Gy irradiation group,and temozolomide treatment group,the radiosurgery in combination of temozolomide group had significantly lower mRNA and protein expressions of MMP-9 and VEGF,and secretion of PRL and GH (P＜0.05) Conclusion Gamma knife radiosurgery combined temozolomide could significantly inhibit the invasive ability and endocrine function of rat pituitary adenoma cell lines GH3 and MMQ,which has better effect than radiotherapy or temozolomide treatment alone.
الملخص
Objective To evaluate the effect of ultra short-term low-dose gamma knife radiation on invasive properties of glioma cells at the genetic level.Methods Malignant glioma cell lines U87 and U251 were treated with gamma knife radiation,respectively,with a marginal doses of 0,4,6,8 and 10 Gy (all to the 80％ isodose line).Real time-PCR was used to measure the mRNA expressions of AKT-1,AKT-2,β-catenin and TCF-4 at 30 min after radiation.Results The expressions of AKT-1,AKT-2,β-catenin,TCF-4 in glioma cell lines after low-dose gamma knife radiation with a marginal dose of 6-8 Gy were significantly increased as compared with those after 0 Gy (P＜0.05); reduced expressions ofAKT-1,AKT-2,β-catenin and TCF-4 after a marginal dose of 10 Gy were found as compared with those after 0 Gy (P＜0.05); the β-catenin and AKT-1 mRNA expressions in U87 cells and TCF-4,AKT-1 and AKT-2 mRNA expressions in U251 cells enjoyed the most obvious increase at a marginal dose of 6 Gy; the TCF-4 and AKT-2 mRNA expressions in U87 cells and β-catenin mRNA expression in U251 cells enjoyed the most obvious increase at a marginal dose of 8 Gy.Conclusion Low-dose gamma knife radiation (6-8 Gy) could increase the β-catenin,TCF-4,AKT-1 and AKT-2 expressions,while high dose (10 Gy) could inhibit these effects in a short time period of 30 min.