title: Differentiation of human fibroblasts to tissue macrophages by the Snyder-Theilen feline sarcoma virus (ST:FeSV): growth modulation of human tumor cell lines in agar.
abstract: BACKGROUND
  Snyder-Theilen feline sarcoma virus (ST:FeSV)-transduced human fibroblasts differentiate into tissue macrophages(1-9). The ST:FeSV-induced macrophages demonstrate macrophage-mediated cytotoxicity (MTC) and antibody-dependent cellular cytotoxicity (ADCC), including growth modulation of tumor cells in agar (3,4,6).
  
  
  METHODS
  Here we tested the effects of ST:FeSV-induced macrophages in agar on the following human tumor cell lines: colon adenocarcinoma, prostate adenocarcinoma, breast adenocarcinoma, malignant melanoma, leiomyosarcoma, fibrosarcoma, and fibrous histiocytoma. The tumor cells were co-incubated in agar with ST:FeSV-induced macrophages in the absence or presence of 10% fetal bovine serum (FBS).
  
  
  RESULTS
  Regardless of serum conditions, the growth of all tumor cells tested was inhibited considerably by the ST:FeSV-induced macrophages. Colon adenocarcinoma cells were the least affected, and fibrosarcoma or fibrous histiocytoma cells were the most sensitive to growth inhibition by the ST:FeSV-induced macrophages. A notable exception was the growth stimulation of breast adenocarcinoma (BT-20; MCF-7), and of prostate adenocarcinoma (TSU-prl) tumor cell lines by the ST:FeSV-induced macrophages in the absence of FBS.
  
  
  CONCLUSIONS
  The results attest to the potency of secreted proteins that are expressed by ST:FeSVinduced macrophages which can modulate tumor cell growth in agar. The results further indicate that serum is likely to have an impact on the effects of these growth regulatory factors on human tumor cells.
authors.affiliation: Laboratory of Cancer Genetics and Cancer Prevention, Department of Veterans Affairs, Medical Research, Bay Pines, Florida 33504, USA.
authors.forename: B
authors.initials: B
authors.lastname: Wesseling
authors.forename: L
authors.initials: L
authors.lastname: Kopelovich
mesh_terms: D001769:Blood; D002454:Cell Differentiation; D002455:Cell Division; D003470:Culture Media; D005347:Fibroblasts / Q000166:cytology*; D006801:Humans; D008264:Macrophages / Q000166:cytology / Q000276:immunology* / Q000821:virology; D009569:Nitric Oxide / Q000502:physiology; D005253:Sarcoma Viruses, Feline; D014161:Transduction, Genetic; D014407:Tumor Cells, Cultured / Q000166:cytology* / Q000276:immunology
chemical_list: D003470:Culture Media; D009569:Nitric Oxide