Rearrangement of c-myc, pim-1 and Mlvi-1 and trisomy of chromosome 15 in MCF- and Moloney-MuLV-induced murine T-cell leukemias.

Provirus insertion near the c-myc, pim-1 or Mlvi-1 genes occurred in 7 out of 59 virally induced T-cell leukemias. C-myc was exclusively rearranged in approximately 10% of MCF247-induced tumors while Mlvi-1 was rearranged to a similar frequency in Moloney-virus-induced lymphomas. Out of 25 karyotyped tumors, 9 (36%) showed trisomy of chromosome 15. Provirus insertion near c-myc, pim-1 or Mlvi-1 occurred both in diploid lymphomas and in tumors with trisomy 15. These results suggest that the molecular and cytogenetic changes observed in murine T-cell leukemias are independent tumor-associated events and that trisomy of chromosome 15 is a common tumor-progression-related event.