Increased in vitro radioresistance of bone marrow fibroblastic progenitors (CFU-F) from patients with acute non-lymphocytic leukemia

The proliferative potential following in vitro irradiation of bone marrow fibroblastic progenitors (CFU-F) derived from four patients with acute nonlymphocytic leukemia (ANLL) and seven nonleukemic subjects was compared. The CFU-F from the ANLL patients were significantly more radioresistant than the CFU-F from the nonleukemic subjects. The increased radioresistance in ANLL patients was evident in both the mean slope of the survival curve (control = −0.385, ANLL = −0.256) and in the Do values (control = 2.68 Gy, ANLL = 4.61 Gy). Thus CFU-F derived from ANLL patients differ from those derived from nonleukemics in both radioresistance and in granulopoietic effects as suggested from previous studies.