Fig. 5

Graphene oxide regulates the cell cycle and promotes differentiation of GSCs via epigenetic mechanisms. a qRT-PCR showed the mRNA levels of the cell cycle regulators CDK4, CDK6 and CyclinD1 in GSCs after GO treatment. b, c GSCs treated with 50 μg/ml GO or control group were stained with PI and the cell cycle distribution was analyzed using flow cytometry. d, e Western blot analysis showed that the level of H3K27me3 was reduced after treatment with GO. f Chromatin immunoprecipitation showed that 50 μg/ml GO decreased the accumulation of H3K27me3 on the promoters of GFAP and TUJ1. Rabbit IgG was used as a negative control. The DNA in each ChIP sample was normalized based on the corresponding input sample. g The mRNA levels of the H3K27me3 methylase EZH2, and demethylases KDM6A and KDM6B in U87 GSCs after treatment with 50 μg/ml GO. h The protein expression level of the H3K27me3 regulator EZH2 was measured by western blot after treatment with 0, 5, 12.5, 25 and 50 μg/ml GO respectively. i Chromatin immunoprecipitation showed EZH2 inhibitor GSK126 decreased the accumulation of H3K27me3 on the promoters of GFAP and TUJ1 compared with control group. Rabbit IgG was used as a negative control. The DNA in each ChIP sample was normalized based on the corresponding input sample. *p < 0.05, **p < 0.01. Data represent the mean ± SEM of at least three independent experiments