SYK inhibition causes cell-cycle arrest only in sensitive DLBCL cells. (A) Effects of PRT318 on cell proliferation were measured by 7-AAD/bromodeoxyuridine (BrdU) incorporation. Two sensitive (LY7 and LY18) and 2 resistant (LY3 and LY4) cell lines were treated for 48 hours with various concentrations of PRT318, as indicated at the top of the dot plots. Percentages of events in each gate were indicated in each of the plots. Quantification of S and G0/G1 phase events are shown in the line graphs next to the dot plots. (B) Effects of PRT318 on cell viability were measured by annexin V/7-AAD double staining. The cell lines were treated for 96 hours with various concentrations of PRT318, as indicated at the top of the dot plots. Percentages of events in each quadrant were indicated in each of the plots. (C) Effects of SYK siRNA on cell proliferation. LY18 and LY4 were transfected with SYK or control siRNA pools and cell proliferation was measured by 7-AAD/BrdU incorporation at 48 hours after transfection.
