Fig. 1: TTFields combined with CUSP9v3 have a synergistic inhibitory effect on the cell viability of glioblastoma cells.

Established (a), primary cultured (b–d) and stem‐like (e–g) glioblastoma cells were treated for 72 h as indicated. Cell viability was determined by MTT assays. Data are presented as mean and SD from at least three independent experiments. *p < 0.05, **p < 0.01, ***p < 0.005. h BLISS analysis was performed for cells treated as described for (a–g). A synergistic interaction is highlighted in red; an additive interaction is highlighted in green and an antagonistic interaction is highlighted in blue. Data are representative for three independent experiments. i, j Microphotographs of PC40 and PC128 spheroids that were grown for 12 d. Treatment as indicated was performed on d5, d7 and d9. Magnification: × 4. k Representative microphotographs of U251 spheroids treated as described for (i, j) and stained with propidium iodide prior to fluorescent imaging (Cytation5 cell imaging multimode reader and Gen5 software, Agilent BioTek, Waldbronn, Germany). Magnification: × 4. l–n PC40, PC128 and U251 spheroids were treated as described for (i, j). CellTiter-Glo® assays were performed to determine the ATP content. Columns: mean. Error bars: SD. N = 3. *p < 0.05, **p < 0.01.