Figure 3
From: The HIF1α/JMY pathway promotes glioblastoma stem-like cell invasiveness after irradiation
A rapid and transient nuclear accumulation of HIF1α is involved in radiation-induced migration of GSCs. (A) Immunostaining of HIF1α in DFO-treated (100 µM, 1 h) or irradiated (0.5 Gy 1 or 4 h PI) TG1N GSCs. Nuclei were counterstained with DAPI. Scale bar: 20 µm. (B) Percentage of intranuclear HIF1α-positive cells after DFO treatment or after (0.5 Gy) irradiation (n = 100 cells per condition; ***p < 0.001). (C) YC1 (50 µM) treatment 2 h prior to irradiation (0.5 Gy) prevented the radiation-induced nuclear accumulation of HIF1α in TG1N GSCs. One hour after irradiation or DFO treatment (100 µM), nuclear HIF1α fluorescence intensity was determined in at least 50 cells per condition (**p < 0.01 and ***p < 0.001). (D) Effects of YC1 or DFO treatments on TG1N GSCs migration velocity 24 h PI. Migration velocity was expressed as percentages of the unirradiated control and calculated from at least 80 cells for each condition (**p < 0.01 and ***p < 0.001). (E) HIF1α knockdown prevented the radiation-induced migration of TG1N cells. TG1N GSCs were transfected with a siRNA targeting HIF1α (siHIF1α) or a scramble control (siCt) and irradiated (0.5 Gy) 24 h later. Twenty-four hours after irradiation, migration velocity was determined and expressed as percentage of the unirradiated control. Data were obtained from at least 70 cells per condition (***p < 0.001).
