The Initial Observation On Malignant Transformation Of The Rats Neural Stem Cells Co-cultured With C6 Glioma Cells In Vitro

Objective:To study whether normal rats nueral stem cells can have malignant transformation when expose to tumor microenvironment in vitro.Methods:1. We established an co-culture model of C6 glioma cell and neural stem cells(NSCs) in a cell co-culture system in vitro.â‘ the experimental group (EG): neural stem cells co-cultured with C6 glioma cell;â‘¡the control group (CG): neural stem cells co-cultured with astrocyte;â‘¢the blank control group: neural stem cells co-cultured with culture medium.2. The morphological changes of NSCs were observed after co-cultivation by phase-contrast microscope and electron microscope.3. MTT assays were performed for the changes of NSCs proliferation.4. The expression of P53 mutant protein were examined by immunofluorescence assays on NSCs after co-cultivation.5. The karyotype analysis of NSCs were examined after co-cultivation.6. The NSCs were implanted into the intracalvarium of Balb/c nude mice after co-cultivation.Results:1. We successfully established an co-culture model of C6 glioma cell and neural stem cells(NSCs) in a cell co-culture system in vitro.2. The morphological changes of NSCs after co-cultivation:â‘ observed by phase-contrast microscope: the volume of neurosphere is bigger and the quantity of cells in the experimental group is more than the control group after 7 days'co-cultivation;â‘¡observed by electron microscope: the nuclear-cytoplasmic ratio is higher and the organelle is more developed in the experimental group than the control group.3. Compared with the control group, the NSCs co-cultured with C6 glioma cells were more powful in proliferation.4. P53 mutant protein wasn't observed in the NSCs co-cultured with C6 glioma cells after 7 and 14 days,but was observed in some of the NSCs after 28 days'co-cultivation. In the control group and the blank control group: P53 mutant protein wasn't observed in the NSCs after 7,14,28 days'co-cultivation.5. The chromosome karyotype analysis of NSCs after co-cultured are all normal in all the three groups.6. The NSCs co-cultured with C6 glioma cells were implanted into the intracalvarium of Balb/c nude mice , there is no tumor formed in all the three groups.Conclusions:1. The C6 glioma cells can promote the proliferation of the NSCs in the cell co-culture system in vitro in some extent.2. This study shows that some of the neural stem cells express P53 mutant protein when exposed to the C6 glioma cells directly,suggesting that tumor microenvironment can cause abnormal gene expression of stem cells.