Pcdna klf4

GSCs-EVs were labeled with PKH-26 red uorescent cell linker kit (Sigma-Aldrich, Merck KGaA, Darmstadt, Germany). Brie y, PKH-26-labeled GSCs-EVs were cultured with U87 cells at 37℃ for 12 h. Afterwards, the cells were rinsed with PBS twice, xed with methanol for 20 min and stained with DAPI for 20 s. The stained cells were observed under a uorescence microscope (Olympus, Tokyo, Japan) to determine the uptake of PKH-26-labeled GSCs-EVs by U87 and U251 cells.
Cell treatment and grouping U87 and U251 cells were treated with 10, 20 and 30 µg/mL EVs. GSCs were added with EV inhibitor GW4869 (Sigma-Aldrich), and then the supernatant was collected to treat U87 and U251 cells as the control group. miR-26a inhibitor and miR-NC (GenePharma, Shanghai, China) were transfected into GSCs using Lipofectamine 2000 (R&D Systems, Minneapolis, MN, USA), and the extracted EVs were recorded as EVs + inhibitor and EVs + inhibitor-NC respectively. U87 and U251 cells were treated with 30 µg/mL EVs. miR-26a mimic, miR-NC, Krüppel-like factor4 (KLF4) overexpression vector pcDNA-KLF4 and control vector pcDNA-NC (GenePharma) were transfected into U87 cells using Lipofectamine 2000. The subsequent experiments were performed 48 h later.