Fig. 5

SAHA induces GSCs senescence via activation of the p38-p53 pathway. a to c GSCs from U87MG cells were collected 7 days after treatment of SAHA at different doses. The cellular lysates were then analyzed by Western blotting with indicated antibodies (a). The senescence-associated β-galactosidase (SA-β-gal) activities were then examined by SA-β-gal kit (Cell Signaling, details described in materials and methods). Photomicrographs of spheroid bodies were randomly selected in microscopic fields (b) and the percentage of SA-β-gal positive cells was quantified; bar, S.D.; ** p < 0.01 (c). d to g GSCs were pre-treated with or without 3 μM SB203580 (SB) for 1 h and then treated with DMSO or with SAHA (1 μM in G, 2.5 μM in d to g) for 7 days. After treatment, cellular senescence was measured by the detection of SA-β-gal activity (d). The percentage of SA-β-gal positive cells was quantified; bar, S.D., *, P < 0.05, **, P < 0.01 (e). The protein lysates were analyzed by Western blotting with indicated antibodies (f and g). h GSCSs were treated with DMSO or with different doses of SAHA as indicated for 2 days. After treatment, the protein lysates were analyzed by Western blotting