Figure 2.

Clonogenic radiation survival curves of bone marrow stromal cell lines derived from MMS350-treated long-term marrow cultures. Adherent cells removed from week 10 long-term marrow cultures were cultured according to previously published methods and clonal cell lines established. Radiation survival curves of those cells removed from longterm marrow cultures derived from mice treated with MMS350 in vivo then treated with MMS350 in vitro, and maintained in MMS350 (100 μM) continually for 10 weeks, and in secondary stromal cell cultures derived at 10 weeks were irradiated in clonogenic survival curve assays according to published methods. Clonal cell lines from control cultures were also derived and radiation survival curves carried-out as described in the methods section for cells treated with MMS350 at the time of irradiation and for 7 days thereafter. The D₀ and ñ evaluation of stromal cells treated freshly with MMS350 were compared to those continuously cultured with MMS350. D₀ and n are shown in Table VI.