Fig. 2.
Chemotherapy drugs more efficiently inhibit neurosphere formation than bulk cell proliferation. We calculated the concentrations of chemotherapy drug required to inhibit neurosphere formation by 50% (sphere IC50), the concentrations of drug required to inhibit bulk cell proliferation by 50% (MTS/MTT IC50) and the concentrations required to inhibit bulk cell proliferation by 90% (MTS IC90)(A–D). Also, normal neurosphere bulk cells are more sensitive to chemotherapy drugs than the transformed PET2 cells (A–B).