TY - JOUR
T1 - Overexpression of C-terminally but not N-terminally truncated Myb induces fibrosarcomas
T2 - A novel nonhematopoietic target cell for the myb oncogene
AU - Press, Richard D.
AU - Reddy, E. Premkumar
AU - Ewert, Donald L.
PY - 1994/4
Y1 - 1994/4
N2 - The myb oncogene encodes a DNA-binding transcriptional transactivator which can become a hematopoietic cell-transforming protein following the deletion of amino acid sequences from either its amino or carboxyl terminus. Although a number of hematopoietic tumors express terminally deleted variants of Myb, the involvement of truncated Myb in nonhematopoietic tumors has not been adequately investigated. To assess the full spectrum of Myb's oncogenic capability, a replication-competent retroviral vector (RCAMV) was used to express a full-length protein (C-Myb), an amino-terminally truncated protein (VCC- or ΔN-Myb), a carboxyl-terminally truncated protein (T-Myb), or a doubly truncated protein (VCT-Myb) in vivo. These viruses were injected intravenously into 10-day chicken embryos, and the infected chicks were monitored for tumors. Approximately 4 to 8 weeks after hatching, the majority (30 of 39 [77%]) of animals infected with the T-Myb retrovirus (without 214 carboxyl-terminal residues) developed nodular muscle tumors which could be identified by both morphologic and immunohistochemical criteria as fibrosarcomas. Identically appearing tumors could also be found in the kidney of some T-Myb-infected animals. The T-Myb-induced fibrosarcomas expressed the appropriately sized T-Myb protein, contained an unaltered proviral T-myb gene, and showed clonal proviral integration sites. In comparison, no sarcomas were observed in any of the animals infected with the amino- terminally truncated (VCC- and ΔN-Myb) or doubly truncated (VCT-Myb) viruses. A loss of carboxyl-terminal but not amino-terminal sequences can thus convert Myb into a potent in vivo transforming protein for nonhematopoietic mesenchymal cells. In comparison, a truncation of either or both ends of the protein can activate Myb into a hematopoietic cell- transforming protein.
AB - The myb oncogene encodes a DNA-binding transcriptional transactivator which can become a hematopoietic cell-transforming protein following the deletion of amino acid sequences from either its amino or carboxyl terminus. Although a number of hematopoietic tumors express terminally deleted variants of Myb, the involvement of truncated Myb in nonhematopoietic tumors has not been adequately investigated. To assess the full spectrum of Myb's oncogenic capability, a replication-competent retroviral vector (RCAMV) was used to express a full-length protein (C-Myb), an amino-terminally truncated protein (VCC- or ΔN-Myb), a carboxyl-terminally truncated protein (T-Myb), or a doubly truncated protein (VCT-Myb) in vivo. These viruses were injected intravenously into 10-day chicken embryos, and the infected chicks were monitored for tumors. Approximately 4 to 8 weeks after hatching, the majority (30 of 39 [77%]) of animals infected with the T-Myb retrovirus (without 214 carboxyl-terminal residues) developed nodular muscle tumors which could be identified by both morphologic and immunohistochemical criteria as fibrosarcomas. Identically appearing tumors could also be found in the kidney of some T-Myb-infected animals. The T-Myb-induced fibrosarcomas expressed the appropriately sized T-Myb protein, contained an unaltered proviral T-myb gene, and showed clonal proviral integration sites. In comparison, no sarcomas were observed in any of the animals infected with the amino- terminally truncated (VCC- and ΔN-Myb) or doubly truncated (VCT-Myb) viruses. A loss of carboxyl-terminal but not amino-terminal sequences can thus convert Myb into a potent in vivo transforming protein for nonhematopoietic mesenchymal cells. In comparison, a truncation of either or both ends of the protein can activate Myb into a hematopoietic cell- transforming protein.
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U2 - 10.1128/MCB.14.4.2278
DO - 10.1128/MCB.14.4.2278
M3 - Article
C2 - 8139533
AN - SCOPUS:0028222952
SN - 0270-7306
VL - 14
SP - 2278
EP - 2290
JO - Molecular and cellular biology
JF - Molecular and cellular biology
IS - 4
ER -