Fig 3. Cell viability after ganetespib, ganetespib with Torin2 and ganetespib with rapamycin treatment.

Ganetespib was serially diluted three-fold from 10 μM to 1.5 nM. The Torin2 concentration was 5nM, and the rapamycin concentration 20 nM. Cell viability was determined 72h after treatment using CellTiter-Glo and XLfit4.0 software. Cell viability is shown in relative control activity, n = 2–4. IC₅₀ was calculated as the drug concentration that reduced cell viability by 50% compared to untreated cells. All TSC1 or TSC2 deficient tumor cell lines showed a strongly decreased cell viability after treatment with ganetespib. Combined therapy of genetespib and rapamycin or genetespib and Torin2 showed an additive effect with even lower IC50 values. However, the significance of this additive effect was not clear.