Fig. 4

(a) Cytotoxic activity of different doses of Bio-nFeR in lung cancer, melanoma, colon cancer, glioblastoma and sarcoma CSC in vitro. The indicated CSC were exposed to 0.1, 0.5, 1, 2, 5, 10, 20 and 30 μM drug doses and cell viability was evaluated by Cell Titer-Glo after 72 h and indicated as percentage versus control cells. b Bio-nFeR antitumour activity in lung cancer, melanoma and colon cancer CSC-derived xenografts. (Upper panels) Growth curves of CSC-derived xenografts in control mice or mice treated with Bio-nFeR at 100 (lung cancer and melanoma) or 150 (colon cancer) mg/kg dose for the indicated times. Mean ± S.D. of three independent experiments is shown. *P < 0.05 **P < 0.01. (lower panels) Table of drug-induced systemic toxicity in the three groups of mice indicated as percentage of body weight loss (BWL) or number of deaths/total number of mice. c Fenretinide levels in plasma and tumours of the same samples as in B. Fenretinide concentration in plasma and tumours is expressed in ng/ml and the corresponding μM concentration, as indicated (tumour density is assumed as approximately =1). d Fenretinide metabolites levels in plasma and tumours of the same samples as in B-C. Fenretinide, 4HPR, OXO-4HPR and DH-4HPR concentration levels in the indicated plasma and tumours of the same samples as in C