Stable expression of the avian retroviral oncoprotein v-Rel in avian, mouse, and dog cell lines.
Overexpression of the retroviral oncoprotein v-Rel can rapidly transform and immortalize a variety of avian cells in culture. However, mammalian models for v-Rel-mediated oncogenesis have been compromised by the fact that high-level expression of v-Rel has been reported to be toxic in many mammalian cell types, including mouse 3T3 cells, Rat-1 cells, and mouse bone marrow cells. In this article, we demonstrate that 3T3 cells can support expression of v-Rel for at least 24 days when infected with a mouse stem cell virus (MSCV) retroviral vector containing v-rel. In retrovirus-infected 3T3 cells, v-Rel is located in the nucleus and can bind to DNA, but does not transform the cells. On the other hand, 3T3 and Rat-2 cells do not express v-Rel after stable transfection with a pcDNA-based v-Rel expression vector. We also show that infection of the IL3-dependent mouse B cell line BaF3 with the MSCV-v-rel vector results in expression of v-Rel, but does not convert these cells to growth factor independence. In contrast to 3T3 cells, the dog osteosarcoma D17 cell line can support a high level of v-Rel expression, after either transfection or infection with a retroviral vector. That is, v-Rel can be stably expressed as a nuclear, DNA-binding protein in D17 cells to approximately the same level as in chicken embryo fibroblasts. These results suggest that the restriction to v-Rel expression in rodent fibroblasts is generally absent in D17 cells and that the type of v-rel expression vector determines whether 3T3 cells can support stable expression of v-Rel. The findings reported here are an essential first step in the development of mammalian systems to study Rel-mediated oncogenesis.
Biology Department, Boston University, 5 Cummington Street, Boston, MA 02215, USA. gilmore@bu.edu
Thomas D
TD
Gilmore
Jims
J
Jean-Jacques
Rebecca
R
Richards
Catherine
C
Cormier
Juhee
J
Kim
Demetrios
D
Kalaitzidis
D016475:3T3 Cells; D000818:Animals; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic; D002478:Cells, Cultured; D002645:Chickens; D004285:Dogs; D005347:Fibroblasts / Q000821:virology; D005822:Genetic Vectors; D051379:Mice; D020572:Oncogene Proteins v-rel / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D051381:Rats; D012190:Retroviridae / Q000235:genetics / Q000472:pathogenicity
D020572:Oncogene Proteins v-rel