Transforming Genes and Target Cells of Murine Spleen Focus-Forming Viruses

Autocrine stimulation after transfer of the granulocyte/macrophage colony-stimulating factor gene and autonomous growth are distinct but interdependent steps in the oncogenic pathway.

“…The myeloproliferative sarcoma virus (MPSV), used as a basis for our vectors, is derived from Mo-MuLV and mos oncogenic sequences but has a wider host range than any of the other Mo-MuLVderived viruses and vectors (9)(10)(11). At least part of this unique property of MPSV is due to mutations in the transcriptional control region, the U3 region of the long terminal repeat (LTR) (12,13).…”

High expression of transgenes mediated by hybrid retroviral vectors in hepatocytes: comparison of promoters from murine retroviruses in vitro and in vivo

“…A series of chloramphenicol acetyltransferase (CAT) reporter gene plasmids were constructed, which contained the U3 regions of spleen focus-forming virus (SFFVp), 7 Myeloproliferative sarcoma virus (MPSV), 8 PCC4-cell-passaged MPSV (PCMV) 9 or Moloney murine leukemia virus (MoMLV) in the same plasmid backbone. These plasmid DNAs were transfected into the cell lines derived from differentiated hepatocellular carcinomas …”

“…3 Although a variety of promoters were examined and used as internal promoters of the vectors, 4-6 cisacting elements in LTRs of various viruses have not been studied in detail especially in hepatocytes. In the present report, we have systematically compared the activities of retroviral cis-acting elements located in the U3 region of the long terminal repeats (LTRs).A series of chloramphenicol acetyltransferase (CAT) reporter gene plasmids were constructed, which contained the U3 regions of spleen focus-forming virus (SFFVp), 7 Myeloproliferative sarcoma virus (MPSV), 8 PCC4-cell-passaged MPSV (PCMV) 9 or Moloney murine leukemia virus (MoMLV) in the same plasmid backbone. These plasmid DNAs were transfected into the cell lines derived from differentiated hepatocellular carcinomas …”

“…A series of chloramphenicol acetyltransferase (CAT) reporter gene plasmids were constructed, which contained the U3 regions of spleen focus-forming virus (SFFVp), 7 Myeloproliferative sarcoma virus (MPSV), 8 PCC4-cell-passaged MPSV (PCMV) 9 or Moloney murine leukemia virus (MoMLV) in the same plasmid backbone. These plasmid DNAs were transfected into the cell lines derived from differentiated hepatocellular carcinomas (HuH-7 10 and PLC/PRF/5 11 ), from an undifferentiated hepatocellular carcinoma (HLE 12 ), from a hepatoblastoma (HepG2 13 ), from a cholangiocelluler carcinoma (KMC-1 14 ) or from a combined hepatocholangiocarcinoma (KMCH-1 15 ).…”

The role of gp55 N-glycosylation in pathogenesis of Friend spleen focus-forming virus

“…Friend spleen focus-forming virus (F-SFFV) is a highly pathogenic, replication-defective retrovirus inducing acute erythroleukaemia in mice which is either associated with a polycythaemia (F-SFFVp) or a slight anaemia (for reviews, see Ruscetti & Wolff, 1984;Ostertag et al, 1987;Kabat, 1989). In both instances, the presence and expression of the viral envelope (env) gene was shown to be essential and sufficient for induction of the disease (Linemeyer et al, 1981(Linemeyer et al, , 1982Machida et al, 1985;Wolff & Ruscetti, 1985Li et al, 1986).…”