Study On Chemoradiotherapy Resistance Of Glioma Stem Cells

Background and Objective:Brain glioma is a kind of malignant tumor disease that Serious damage to people’s physical and mental health and glioma morbidity is increasing year by year. At least half the number of glioma patients’ survival rate less than 5 years. The study that based on glioma stem cell theory is a resarch about chemotherapy resistance.Methods:There are two parts of the experiment. The first part: to select U251 cell line whose marker is CD133 though brain glioma pathological tissue. Then they will be performed about both nude mice transplantation assay which induced by tumor and single cell clone formation assay. The second part: glioma stem cells will be irradiated by high-energy linear accelerator of X-ray radiation for 72 h. Cell activity change will be compared with each other by MTT determination at different times. At last, radiotherapy will be performed.Results:The first part: there are obvious positive expression in regard to ABCG2 and CD133 in cell lines; The cell lines showed suspension growth; CD133 positive rate was 88.1%, 91.4%, 87.3% after separation experiment; The results showed that CD133- cells positive rate was 1.4%-4.6%, and CD133+ cells positive rate was 78.4%-92.3% after single cell clone formation experiment.Then there was abdominal mass vaccination in nude mice with CD133+, but there was no abdominal mass vaccination in nude mice with CD133-. The second part: with the increased radiation dose and time, U251 tumor cell activity had decreased significantly(P<0.01); With the same dosage and different time, there were different effects, but cell activities were decreased in any ways(P<0.01); After 72 h X-ray treatment, ABCG2 and CD133 expression rate was increased, and CD133 apoptosis rate showed growed increased too. There were significantly difference between U251 cells and CD133 cells’ apoptosis rate(P<0.01). CD133- and CD133+ cell lines mortality showed significant decline when they had been treated by temozolomide(TMZ).Conclusions:Vitro experiment indicated that there are GSCs which are marked by ABCG2+and CD133+ in the U251 glioma cell line. GSCs showed significant resistance when they had been treated by X-ray radiation or TMZ chemotherapy, but GSCs’ resistance decreased significantly when they had been treated by X-ray radiation and TMZ chemotherapy.