title: Transformation of chicken myelomonocytic cells by a retrovirus expressing the v-myb oncogene from the long terminal repeats of avian myeloblastosis virus but not Rous sarcoma virus.
abstract: To test the effect of long terminal repeat (LTR) regulatory sequences on the transforming capability of the v-myb oncogene from avian myeloblastosis virus (AMV), we have constructed replication-competent avian retroviral vectors with nearly identical structural genes that express v-myb from either AMV or Rous sarcoma virus (RSV) LTRs. After transfection into chicken embryo fibroblasts, virus-containing cell supernatants were used to infect chicken myelomonocytic target cells from preparations of 16-day-old embryonic spleen cells. Both wild-type AMV and the virus expressing v-myb from AMV LTRs (RCAMV-v-myb) were able to transform the splenocyte cultures into a population of immature myelomonocytic cells. The transformed cells expressed the p48v-Myb oncoprotein and formed compact foci when grown in soft agar. In contrast, the virus expressing v-myb from RSV LTRs (RCAS-v-myb) was repeatedly unable to transform the same splenocyte cells, despite being able to infect fibroblasts with high efficiency. This difference in the transforming activities of v-myb-expressing viruses with different LTRs most likely results from the presence of a factor (or factors) within the appropriate myelomonocytic target cell that promotes specific expression from the AMV but not from the RSV LTR.
authors.affiliation: Wistar Institute of Anatomy and Biology, Philadelphia, Pennsylvania 19104-4268.
authors.forename: R D
authors.initials: RD
authors.lastname: Press
authors.forename: A
authors.initials: A
authors.lastname: Kim
authors.forename: D L
authors.initials: DL
authors.lastname: Ewert
authors.forename: E P
authors.initials: EP
authors.lastname: Reddy
mesh_terms: D000818:Animals; D009189:Avian Myeloblastosis Virus / Q000235:genetics*; D001358:Avian Sarcoma Viruses / Q000235:genetics*; D002472:Cell Transformation, Viral / Q000235:genetics*; D002478:Cells, Cultured; D002642:Chick Embryo; D005347:Fibroblasts / Q000382:microbiology; D005822:Genetic Vectors / Q000235:genetics; D020626:Oncogene Proteins v-myb; D009857:Oncogenes / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D015682:Retroviridae Proteins, Oncogenic / Q000096:biosynthesis / Q000235:genetics; D013154:Spleen / Q000166:cytology / Q000382:microbiology; D014162:Transfection
chemical_list: D020626:Oncogene Proteins v-myb; D015682:Retroviridae Proteins, Oncogenic