| Part 1Survival analysis of postoperative concurrent chemoradiotherapy for glioblastoma multiformeObjective:To analyze the prognostic factors related to survival in patients with glioblastoma after postoperative radiotherapy,and to explore the clinical characteristics of intervention in treatment,so as to provide a basis for further research.Patients and methods:A total of 71 patients with glioblastoma treated by postoperative radiotherapy in the first affiliated Hospital of Nanjing Medical University(May 2016 to March 2019)and the Department of radiotherapy of Qinhuai Medical Zone of Eastern Theater General Hospital(May 2012 to May 2018)were collected.The relevant clinical data were sorted out.IBM SPSS 24 statistical software package was used for data analysis.The Kaplan-Meier method was used to calculate the OS(overall survival)and PFS(progression free survival).Logrank method was used for univariate analysis and statistical test of clinical parameters.Cox regression model was used for multivariate analysis of clinical parameters.Results:The median follow-up time was 24.9 months(95%CI(confidence interval),21.6 28.1).The median OS of all patients was 16.9 months(95%CI:12.8-21.0).The 1,2-and 3-year survival rates were 75.3%,32.2%and 22.1%,respectively.The median PFS was 9.8 months(95%CI:9.2-10.4).The 1,2-and 3-year tumor progression-free survival rates were 39.6%,24.2%and 19.4%,respectively.The results of Logrank univariate analysis showed that the KPS score before radiotherapy(χ2=8.265,p=0.004),the invasion of important brain structures(χ2=10.993,p=0.001)and postoperative residue(χ2=5.454,p=0.020)were significantly correlated with the total survival time of the patients,and the influencing factors of PFS included KPS score before radiotherapy(χ2,p=8.444)and the invasion of important brain structures(χ2=11.370,p=0.004).The analysis of OS by Cox regression model showed that the invasion of important brain structure(HR=2.997,95%CI,1.449-6.199,p=0.003)and KPS score(HR=0.412,95%CI,0.218-0.778,p=0.006)were independent prognostic factors.Furthermore,brain structural invasion(HR=3.572,95%CI,1.786-7.143,p=0.000)and KPS score(HR=0.390,95%CI,0.217-0.700,p=0.002)were also independent prognostic factors of PFS.There was no significant improvement of OS(χ~2=0.980,p=0.341)and PFS(χ~2=0.200,p=0.655)in patients with radiotherapy dose higher than 60Gy.1case of grade 3 toxicity of the hematological system was observed during the treatment.Except for 1 case of myocardial infarction and 1 case of cerebral infarction,the other causes of death were related to intracranial tumor.Conclusion:We found in this study that preoperative tumor invasion of important intracranial structures and KPS score before radiotherapy are independent prognostic factors,which were highly related to survival and progression-free survival.A small increase in the dose of radiotherapy cannot improve the prognosis of patients.Part 2Temozolomide(TMZ)combined with radiotherapy induced glioma cells apoptosis through excessive oxidative stressObjective: To explore the possible mechanism of simultaneous radiotherapy and chemotherapy combined with temozolomide to significantly improve the prognosis of postoperative glioma patients from the point of view of oxidative stress.Methods: Glioma cell lines GL261 and C6 were treated with TMZ in vitro for 24 h,stemness markers CD144,Sox2,ZEB-1 and survivin were detected by western blot,reactive oxygen species(ROS)of GL261 and C6 cells were measured by ROS probes,and Nrf-2,Keap-1 were detected by wastern-blot.While TMZ combined with radiotherapy,apoptosis,stemness,colony forming efficiency and oxidative stress level of tumor cells were investigated.Finally,at the animal level,the method of transplanting tumor in nude mice was used to observe the growth of tumor cells in vivo and the changes of reactive oxygen species in tumor tissue cells after TMZ combined with radiotherapy.The experimental data were processed by Graph Pad Prism5 software.The significant differences among groups were compared by One-way ANOVO,and Tukey method,and the mean values were compared by t-test.Results: After GL261 and C6 were treated with TMZ(100 μM)for 24 hours,the expression of CD144,Sox2,ZEB-1 and survivin increased,while the oxidative stress pathway was activated,the level of ROS increased,the expression of Nrf-2 increased and the expression of Keap-1 decreased.While combined with radiotherapy,oxidative stress was overactivated,the expression of Nrf-2 was significantly increased and the expression of Keap-1 was significantly decreased.The apoptosis rate of GL261 tumor cells was significantly higher than that of the control group.At the same time,the stemness markers such as ZEB-1,Sox2 and CD144 decreased.In the colony forming experiment,the colony forming efficiency of TMZ combined with radiotherapy group was 1.14%,which was significantly lower than that of the TMZ group(4.67%)and radiotherapy group(3.64%).The mean tumor volume in vivo of the combined treatment group was 2.34mm3,which was significantly smaller than that of the TMZ group(59.38mm3)and the control group(31mm3).Excessive oxidative stress was also observed in tumor tissues of nude mice.Conclusion: The TMZ induced stemness and oxidative stress of GL261 and C6 could increase the tolerance to drugs.Radiotherapy combined with TMZ treatment of glioma cells can induce excessive oxidative stress,which can lead to decreased stemness and promote the apoptosis of glioma cells. |
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