Figure 1.

Clonogenic survival of human glioma cells treated with BO-1051. (A) Chemical structure of 1-{4-[bis(2-chloroethyl)amino]phenyl}-3-[2-methyl-5-(4- methylacridin-9-ylamino)phenyl]urea (BO-1051). (B) U87MG, (C) U251MG and (D) GBM-3 cells were exposed to escalating doses (50-400 nM) of BO-1051 or vehicle (DMSO). At 6, 12 and 24 h after the addition of BO-1051, the BO-1051- containing medium was removed, rinsed, and then fed with fresh growth media. Colony- forming efficiency was determined 10-14 days later, and the survival fractions of BO-1051-treated cells were calculated after normalizing for the plating efficiencies of untreated cells. Points: mean for at least 3 independent experiments; bars, SD.