Proliferation and cell growth assays

Cell viability of adherent cells was measured by WST-1 proliferation assay (Roche, 11644807001) or CellTiter- Glo Luminescent cell viability assay (Promega, Madison, WI, USA) for GSCs, using GloMax Explorer instrument (Promega, G9242), according to the manufacturer’s instructions. GSC spheroids were analyzed by scanning the wells in InCell Analyzer 2200 (GE), stitching the pictures to obtain full-well images, and measuring the spheroids’ size using Fiji Image J software (NIH, open source). Generally, the experiments were repeated at least three times for each experimental condition.