FIGURE 1 from PARP Inhibitors Effectively Reduce MAPK Inhibitor Resistant Melanoma Cell Growth and Synergize with MAPK Inhibitors through a Synthetic Lethal Interaction In Vitro and In Vivo
MAPKi resistant melanoma cells are highly susceptible to PARPi treatment. A, MUH cell viability assay of vemurafenib sensitive (S) and resistant (R) melanoma cell lines as well as PDX R cells treated with different concentrations of PARPi (olaparib and talazoparib) starting at 100 μmol/L for 72 hours. Comparison of fits of the nonlinear regression was performed to analyze statistical differences between S and R cells. IC50 levels are shown. B, NSG mice were treated with 2 mg/kg/day talazoparib (Tala.) or the same solvent without talazoparib (Ctr.). The xenograft tumor volume in percent compared with treatment start over time is shown. C, The final tumor volume of the individual mice is depicted. Multiple t test was used to compare the control (Ctr.) group to the talazoparib (Tala.) group. D, Representative pictures of the excised tumors are illustrated.