Figure 5.

Investigation of factors regulating leukemia latency. (A) Limiting dilution assays showed that lowering the number of transplanted cells under certain thresholds resulted in engraftment failure (left) and better survival (right) in both standard (upper) and long-latency (lower) engrafters. (B) The frequency of leukemic cells homing to the BM was higher in standard engrafters than in long-latency engrafters. The data shown are from three standard (patients #2, #5, #6) and three long-latency engrafting AML cases (patients #11, #17, #18). (C, D) Comparable Ki67 positivity in standard vs. long-latency engrafting AML cells infiltrating murine BM (C). Representative pictures for both CD33 and Ki67 staining of two standard engrafters (patients #2, #4) and two long-latency engrafters (patients #13, #16) (D). For reasons of consistency only BM of mice showing >20% infiltration with human cells were included in the analysis.