A Preliminary Study On The Role Of Notch1in Sensitivity To Chemotherapeutic Drugs In Human Glioma Cell

Objective：1. To explore if Notch1signal affects on the sensitivity of human glioma U251cells to chemotherapy drug.2. To investigate the correlation between Notch1and multidrug resistant genes(MDR and MRP1) expressions in human glioma cell.Methods：1. U251cell lines which steadily over-expressed NICD (Notch1intracellulardomain) or knock-down of Notch1gene were obtained by building NICDover-expression plasmid vector and Notch1sh-RNA plasmid vector, packaginglentivirus, and transfection.2. The sensitivities to chemotherapy drugs BCNU and VM-26in the U251cellswere measured by MTT assay3. Expressions of MDR1and MRP1gene in the U251cells were detected byQ-PCR, Western blot and ICC.4. Expressions of Notch1, MDR1and MRP1genes in human glioma tissuesamples were detected by IHC.Results： 1. Successfully obtained U251cell lines which steadily over-expressed NICDor knock-down of Notch1gene.2. MTT assay showed that the IC50of cell lines with over-expression NICD(Plvx-NICD) was higher than that of control group (plvx). The IC50value ofcell line with Notch1RNAi was lower than that of control (sh-NC).3. The results of Q-PCR, Western Blot and ICC indicated MDR1and MRP1genes were higher expression in U251cell lines with over-expression of NICD.MDR1and MRP1gene were lower expression in Notch1knock-down U251cellline compared to controls.4. Experiment results of immunohistochemistry showed that MDR1and MRP1protein were observed in human brain glioma tissue samples. The expressionlevel of Notch1、 MDR1and MRP1were positively correlated with thepathologic stage in gradesⅠ, Ⅱ and Ⅲ of glioma.Conclusions1. Notch1gene involved in regulation of the sensitivity to chemotherapy drugsBCNU and VM–26in human glioma U251cell.2. Notch1signal can influence the expression of MDR1and MRP1gene. Inhuman glioma U251cells，Notch1involved in tumor multi-drug resistant byup-regulating the expressions of MDR1and MRP1.3. The expression of Notch1and MRP1、MDR1were positive correlation inhuman brain glioma cells.