A coordinated proto-oncogene expression characterizes MCF 247 murine leukemia virus-induced T-cell lymphomas irrespectively of proviral insertion affecting myc loci.
Proto-oncogene transcriptional activation was analyzed in a group of MCF 247 MuLv-induced T-cell lymphomas to identify transformation-specific gene activations and determine whether the proviral insertion near a myc gene could promote a peculiar mechanism of transformation through a differential proto-oncogene expression pattern. Of the six lymphomas analyzed, three showed the MCF 247 provirus integrated within the N-myc locus, one carried the provirus integrated near c-myc, whereas for the remaining two, no evidence of proviral integrations in any of the known myc loci was obtained. Independently of the integrative events, the pattern of proto-oncogene expression was almost identical in all six lymphomas. These findings seem to rule out the existence of a peculiar pathway of transformation associated with the proviral insertion near a myc locus. Moreover, the transcription pattern observed was qualitatively identical to that displayed by normal thymocytes; only quantitative differences in c- or N-myc, c-myb and Ha-ras were observed. These results suggest that the T-cell proto-oncogene activation program is not qualitatively affected by the transforming event(s).
Experimental Oncology I, Centro di Riferimento Oncologico, Aviano, Italy.
M
M
Boiocchi
R
R
Dolcetti
R
R
Maestro
G
G
Feriotto
S
S
Rizzo
V
V
De Re
F
F
Sonego
D000818:Animals; D015152:Blotting, Northern; D015139:Blotting, Southern; D002478:Cells, Cultured; D015342:DNA Probes; D005260:Female; D015870:Gene Expression; D066298:In Vitro Techniques; D008223:Lymphoma / Q000235:genetics*; D008297:Male; D051379:Mice; D008806:Mice, Inbred AKR; D008908:Mink Cell Focus-Inducing Viruses; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D011519:Proto-Oncogenes; D012313:RNA / Q000032:analysis; D013601:T-Lymphocytes; D014158:Transcription, Genetic
D015342:DNA Probes; D011518:Proto-Oncogene Proteins; D012313:RNA