Trisomy 15 and other nonrandom chromosome changes in Rauscher murine leukemia virus-induced leukemia cell lines

The cytogenetics of Rauscher murine leukemia virus-induced erythroid, myeloid, and lymphatic leukemias were studied in BALB/c and DBA/2 mice. In primary virus-induced leukemias, no chromosome abnormalities were found. However, in tumors derived from transplanted leukemia tissue and in cell lines obtained from these tumors, euploidy and mostly aneuploidy were observed that varied according to the type of tumor cells and the number of passages. Eleven erythroleukemia cell lines showed aneuploidy from the first in vivo transplant stage on. Nonrandom abnormalities were found: trisomy 15 in 9 of 11 lines, followed by trisomy 3 in 8 of 11 lines and monosomy 6 in 5 of 11 lines. Subsequent evolution of the karyotypes was frequent (10 of 11 lines) and rapid. In vivo cell lines established from these tumors showed many structural rearrangements. Three myeloid lines revealed a stable karyotype with no or only minor changes: trisomy 15 in 1 line and normal diploid in 2 lines. One lymphatic leukemia cell line established in vitro presented with a very stable karyotype: trisomies 14 and 15. Another in vivo transplantable line showed trisomies 11, 9, and 17. These results suggest that trisomy of chromosome 15 plays a significant role in tumors derived from different types of mouse leukemias.