Fig. 4.

NF1^-/- tumor cells exhibit mTOR hyperactivation and are highly sensitive to rapamycin. (A) Western blot analysis of two independently derived patient-matched NF1^+/- and NF1^-/- Schwann cells grown in 0.1% serum devoid of exogenous growth factors. (B) Western blot analysis of an NF1^-/- tumor cell line treated for 30 min with the following concentrations of inhibitors: DMSO, 0.1%; rapamycin, 20 nM; wortmannin, 200 nM. (C) NF1^-/- tumor cell lines were grown for 7 days in the presence of the indicated concentrations of rapamycin and counted in triplicate.