Fig. 1

Functional characterization of chemotherapy resistant MB-R cells. A Drawing summarizing the VECC treatment schedule (one VECC exposure per week for 24 h) to which MB cell lines and primary cultures (MB-S) have been subjected in order to eventually acquire drug resistant traits (MB-R). B Dose–response curves displaying increased resistance to VECC treatment (72 h) of MB-R models relative to their naïve/sensitive counterparts (MB-S). GI₅₀ ratio: MB-R GI₅₀/MB-S GI₅₀ (n = 6). C Growth curves showing that both MB-S and MB-R cells possess equivalent proliferation (within 96 h) as measured by trypan blue exclusion assays (n = 3). D Limiting dilution assays comparing self-renewal potential of MB-S and R cells. Initiating cell frequency F of cells is reported. p calculated by extra sum-of-squares F test (n = 4). E Representative cytofluorimetric plots displaying functional assessment of MB-S/R drug extrusion potential by staining with Rho 123. Control unstained cells are reported as solid grey distributions