Absence of trisomy 15 in chemically induced murine T-cell lymphomas.

Trisomy 15 is a frequent chromosomal abnormality found in murine thymic tumors that develop spontaneously or by induction with irradiation, chemical carcinogens, or leukemogenic retroviruses. The results of our studies demonstrate that T-cell lymphomas induced in RF mice with the chemical carcinogen 3-methylcholanthrene predominantly exhibit a normal diploid complement of chromosomes with no evidence of chromosome 15 trisomy after in vivo and in vitro passage. We conclude that accumulation of aneuploidy is not necessary for maintenance of the tumor phenotype and that chemically induced lymphomas can develop in a defined subpopulation of T cells in the absence of trisomy 15.