The Study On Expression Relationship Of Hsf1 And P-glycoprotein In Rat C₆ Glioma Cells After Adriamycin Chemotherapy

ObjectiveGliomas is one of the most common malignancy in central nervous system. After operation, chemotherapy is critically important. Besides overcoming blood - brain barrier, another major problem in gliomas treatment is chemotherapy resistance.The failure of cancer treatment was due to multidrug resistance (MDR) occurring to tumor cells. Numerous studies found that P - glycoprotain( P - gp) is often overexpressed in MDR tumor cells. P - gp which linked to MDR is encoded by multidrug resisrance gene 1 ( mdr1).Heat shock transcription factor ( Hsf) are sets of proteins which rifeness exist in biology cells, their structure and function have abroad alike, and can regulate the expression of heat shock protein ( HSP) families. Hsf1 is very sensitivity to stimuli. On the stimulative, Hsf1 monomer can combine to trimerization and bound the heat shock element (HSE) located in the HSP gene, then promote effective expression of HSP.Recent studies found that Hsf1 can regulate not only the expression of HSP but also P - gp. Mdr1 promoter has been shown to contain HSE, heat shock or sodium arsenite increase the activity of mdr1 via Hsf1. The purpose of our study is to observe the expression change of Hsf1 and P - gp in C₆ glioma cells after adriamycin chemotherapy.Methods1. ADM was dissolved to culture medium, C6 glioma cells were cultured inculture medium with 2ug/ml ADM for 4 hours.2. The expression of Hsfl and P - gp in C6 glioma cells before chemotherapy and after chemotherapy for additional 2h^4h^8hN12h^24h were detected with western blot;Furthermore, they were detected at 8h after chemotherapy when C6 glioma cells were pretreated by quercetin ( Qu) for 1 hour before chemotherapy.3. Image analysis: Using electrophoresis gel imaging analysis instrument scan NC membrane. Analysis IDV of every group to be the relative content of Hsfl and P - gp.4. Statistic analysis: All data use (x ±s) to express. Use spssll.O to t test for comparing the difference of groups.Results1. The expression change of Hsfl in C6 glioma cells after ADM chemotherapy : The trimerization of Hsfl s content markedly increased at 2h, at 4h reached the peak, increased 2. 81 folds compared with that of the control group, at 8h, 12h, 24h after chemotherapy, it decreased gradually. The trimerization of Hsfl s content in test groups compared with that of the control group P <0.05.2. The expression change of P - gp in C6 glioma cells after ADM chemotherapy: The content of P - gp gradually increased at 2h and 4h, at 8h reached the peak, increased 1.97 folds compared with that of the control group, at 12h, 24h after chemotherapy, it decreased gradually. The content of P - gp in test groups compared with that of the control group P <0.05.3. The expression change of Hsfl in C6 glioma cells after Qu pretreatment + additional 8h after ADM chemotherapy;The trimerization of Hsfl's contentdecreased when concentration of Qu increased;but it's content of lOumol/L group compared with control group P >0.05;that of 100 umol/L, 500 umol/L, 1000 umol/L groups compared with control group P <0.05;1000 umol/L group most effectively inhibit the trimerization of Hsfl "s content.4. The expression change of P - gp in C6 glioma cells after Qu pretreatment + additional 8h after ADM chemotherapy: The change of P - gp's content was as same as the trimerization of Hsfl. The content of P - gp decreased when con-centration of Qu increased;but it's content of lOumol/L group compared with control group P >0.05;that of 100 umol/L, 500 umol/L, 1000 umol/L groups compared with control group P <0. 05;1000 umol/L group most effective inhibit the content of P - gp.ConclusionADM chemotherapy can increase the activity of Hsfl and the expression of P - gp. Qu can inhibit the activity of Hsfl in a dose - dependent manner. The expression of P - gp decreased when the activity of Hsfl was inhibited.