Glycogen synthase kinase-3β regulates astrocytic differentiation of U87-MG human glioblastoma cells
Abstract
Aim: To evaluate the role of glycogen synthase kinase-3β (GSK-3β) in the induced differentiation of human glioblastoma cells.
Methods: Cell proliferation was determined by bromodeoxyuridine (BrdU) incorporation assay. The protein level of p-GSK-3β, GSK-3β, glial fibrillary acidic protein (GFAP) and proliferating cell nuclear antigen (PCNA) were determined using Western blots. The overexpression of mutant GSK-3β was analyzed by immunocytochemistry.
Results: The biotoxin cholera toxin is capable of inducing differentiation of U87-MG human glioblastoma cells, which is characterized by morphological changes to astrocytic phenotype, increase in differentiation marker protein GFAP and decrease in proliferation. GSK-3β activation is induced during this differentiation. Small interfering RNA against GSK-3β suppresses the induced-differentiation in U87-MG cells. Conversely, overexpression of a constitutively active form of human GSK-3β (pcDNA3-GSK-3β-S9A) mutant leads to differentiation of U87-MG cells.
Conclusion: Our findings suggest that GSK-3β plays an important role in astrocytic differentiation of human glioblastoma cells and may be a novel therapeutic target in the malignant tumor.
Keywords:
Methods: Cell proliferation was determined by bromodeoxyuridine (BrdU) incorporation assay. The protein level of p-GSK-3β, GSK-3β, glial fibrillary acidic protein (GFAP) and proliferating cell nuclear antigen (PCNA) were determined using Western blots. The overexpression of mutant GSK-3β was analyzed by immunocytochemistry.
Results: The biotoxin cholera toxin is capable of inducing differentiation of U87-MG human glioblastoma cells, which is characterized by morphological changes to astrocytic phenotype, increase in differentiation marker protein GFAP and decrease in proliferation. GSK-3β activation is induced during this differentiation. Small interfering RNA against GSK-3β suppresses the induced-differentiation in U87-MG cells. Conversely, overexpression of a constitutively active form of human GSK-3β (pcDNA3-GSK-3β-S9A) mutant leads to differentiation of U87-MG cells.
Conclusion: Our findings suggest that GSK-3β plays an important role in astrocytic differentiation of human glioblastoma cells and may be a novel therapeutic target in the malignant tumor.