Alpelisib

For in vitro doxorubicin drug testing, OS cells were cultured for 14 days and exposed to drug at the dose(s) indicated in each figure for 48 hours. IGF-1R inhibitor (PPP) and IGFBP-5 treatments were administered at 10nΜ and 100 ng/mL, respectively, for 48 hours. For in vitro treatment with alpelisib and cetuximab, PDX cells were first cultured for 7 days then exposed to each drug across a wide range of dose(s) for up to 21 days. In vitro cell viability was quantified using bioluminescence imaging (BLI) or Alamar Blue Cell Viability reagent (Thermo Fisher Scientific). IC₅₀ values for alpelisib and cetuximab treatment in vitro were estimated by performing non-linear curve fitting using the model log(inhibitor) vs. response on GraphPad Prism. For in vivo doxorubicin treatment, mice were treated with 4 mg/kg of doxorubicin following 14 days of tumor inoculation and tumor burden was assessed using BLI before treatment and after 48h of treatment. For in vivo alpelisib experiments, mice were treated daily with 50mg/kg of alpelisib (MedChem Express) following 7 days of tumor inoculation. Tumor burden was evaluated using BLI twice per week. For all assays, cell viability after drug treatment was normalized to untreated controls.