Chromosome changes (trisomies #15 and 17) associated with tumor progression in leukemias induced by radiation...

An experimental system was developed that permitted nonrandom chromosome changes that occur in radiation leukemia virus (RadLV)-induced lymphomas to be followed during tumor progression. RadLV variant-induced preleukemia and leukemia cells originating from female inbred C57BL/6 mice were injected into male animals of the same strain. Since all donors were females and all recipients were males, the sex chromosome complements (XX and XY) were used to distinguish the preleukemia and leukemia cells from those of host origin. The G-banding analysis revealed that more than 50% of animals that were inoculated with preleukemia cells and that developed leukemia possessed tumor stem-lines of 41 chromosomes with a tristomy of chromosome #15. In animals inoculated with overt leukemia cells and in which tumor progression occurred, the G-banding an additional trisomy of chromosome #17. The cytogenic data strongly suggested that the trisomy of chromosome #15 was the first specific tumor-associated chromosome change that occurred in the process of conversion of RadLV-induced preleukemia cells to fully autonomous tumor cells.