Spi-1 oncogene activation in Rauscher and Friend murine virus-induced acute erythroleukemias.
The Friend viruses, like the Rauscher virus, cause murine acute erythroleukemias which evolve in a similar multistep process. In previous studies it has been described that the late malignant proerythroblastic transformation induced by the polycythemia-inducing strain of Friend spleen focus-forming virus (SFFVP) is correlated with Spi-1 oncogene activation by insertional mutagenesis. In this paper we report that Spi-1 genomic rearrangements were also observed in 90% of tumors induced by the anemia-inducing strain of Friend spleen focus-forming virus (SFFVA) and in all Rauscher-induced tumors analyzed. SFFVA and Rauscher proviral insertions occurred in the viral integration cluster previously characterized in SFFVP-induced tumors. The Spi-1 1.4-Kb messenger RNA was found highly expressed in all SFFVA and Rauscher-induced malignant cells as compared to normal tissues. The nucleotide sequence of Spi-1 cDNA isolated from a library constructed from SFFVA-induced tumor cells revealed no difference between the Spi-1 gene transcripts expressed in both SFFVP and SFFVA-induced leukemic cells. These results indicate that Spi-1 gene activation is a general feature in the malignant proerythroblastic transformation which occurs in mice infected with Friend and Rauscher viruses.
Moreau-Gachelin
F
F
INSERM U-248, Faculté de Médecine Lariboisière-Saint-Louis, Paris, France.
Ray
D
D
de Both
N J
NJ
van der Feltz
M J
MJ
Tambourin
P
P
Tavitian
A
A
D000208:Acute Disease; D000818:Animals; D005622:Friend murine leukemia virus / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D015321:Gene Rearrangement; D005814:Genes, Viral; D009052:Leukemia Virus, Murine / Q000235:genetics*; D004915:Leukemia, Erythroblastic, Acute / Q000235:genetics*; D007942:Leukemia, Experimental / Q000235:genetics; D051379:Mice; D008811:Mice, Inbred DBA; D009857:Oncogenes; D011925:Rauscher Virus / Q000235:genetics*; D013155:Spleen Focus-Forming Viruses / Q000235:genetics*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured