FIGURE 6.

PTP1B inhibition affects viability of Bcr-Abl-expressing cells and increases efficiency of imatinib mesylate. A, TonB.210 cells were treated with or without DOX for 48 h. PTP1B inhibitor was included for the final 24 h at stated doses. Cell viability was measured using the CellTiter-Blue viability assay (* represents p < 0.05 as analyzed by Student's t test). % of Unt, result expressed as percentage of untreated cells. B, TonB.210 were treated as in A with the addition of indicated doses of imatinib mesylate for the final 24 h followed by CellTiter-Blue viability assay. IC₅₀ values were calculated using a four-parameter sigmoidal model. ∅, PTP1B, PTP1B inhibitor. C, K562, LAMA-84, and MV4–11 cells were treated with PTP1B inhibitor (250 μm) or dimethyl sulfoxide (DMSO) vehicle for 24 h and then assayed for cell viability using the CellTiter-Blue viability assay (* represents p < 0.005 as analyzed by Student's t test).