Autocrine transformation of human hematopoietic cells after transfection with an activated granulocyte/macrophage colony stimulating factor gene.
The effects of constitutive cytokine gene expression on the growth-factor-dependence of the human erythroleukemic TF-1 cell line have been determined. TF-1 cells normally require the presence of exogenous cytokines to proliferate in vitro. TF-1 cells were transfected with constructs containing either the germline granulocyte-macrophage colony-stimulating factor (GM-CSF) gene or the GM-CSF gene linked to the Moloney murine leukemia virus (Mo-MuLV) long terminal repeat. The Mo-MuLV-LTR, which contains a strong transcriptional enhancer, was added to stimulate the constitutive expression of the GM-CSF gene. Transfection with the germline GM-CSF gene did not abrogate the cytokine dependence of TF-1 cells, indicating that inheritance of an extra copy did not result in sufficient GM-CSF expression to abrogate cytokine dependence. In contrast, transfection with the LTR-modified GM-CSF gene resulted in the isolation of cells that proliferated in the absence of exogenous GM-CSF. The LTR increased nascent transcription and accumulation of GM-CSF mRNA transcripts, which had a normal half-life. This increase in GM-CSF expression led to secretion of sufficient GM-CSF to support the growth of the parental TF-1 cells. These results indicate that the deregulated expression of human cytokine genes induced by certain retroviral LTRs can result in their conversion into hematopoietic-specific oncogenes. These modified human cell lines provide a model to investigate autocrine transformation and therapy of acute myelogenous leukemia as well as other hematopoietic disorders.
Hoyle
P E
PE
Department of Microbiology and Immunology, East Carolina University School of Medicine, Greenville, NC 27858, USA.
Steelman
L S
LS
McCubrey
J A
JA
D019898:Autocrine Communication; D015152:Blotting, Northern; D015139:Blotting, Southern; D002455:Cell Division / Q000187:drug effects; D002471:Cell Transformation, Neoplastic; D016207:Cytokines / Q000235:genetics / Q000494:pharmacology; D004742:Enhancer Elements, Genetic; D015972:Gene Expression Regulation, Neoplastic; D005814:Genes, Viral / Q000235:genetics; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D006133:Growth Substances / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D004915:Leukemia, Erythroblastic, Acute; D008979:Moloney murine leukemia virus / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics; D014162:Transfection; D014407:Tumor Cells, Cultured
D016207:Cytokines; D006133:Growth Substances; D012333:RNA, Messenger; D016178:Granulocyte-Macrophage Colony-Stimulating Factor