Expression of autocrine motility factor receptor in serum- and protein-independent fibrosarcoma cells: implications for autonomy in tumor-cell motility and metastasis.
The motile response of serum-dependent (Gc-4 SD) and protein-independent (Gc-4 PF) murine fibrosarcoma cells to monoclonal antibody (MAb) that binds to gp78 a cell-surface receptor (M(r) 78,000) for an autocrine motility factor (AMF) was analyzed. The Gc-4 PF cells responded to the anti-gp78 by increased motility in vitro (3-fold) and increased lung colonization in vivo (8- to 20-fold), while the serum-dependent counterpart failed to respond to motile stimulation both in vitro and in vivo. Immuno-analysis of cell-surface expression and cell extracts revealed a smaller amount of gp78 in Gc-4 SD cells than in Gc-4 PF cells. Both cell lines secrete an equal amount of AMF to the culture media. Our results suggest that protein-free culture of Gc-4 PF cells is associated with high response to AMF and with high expression of its receptor, and that autonomous motile regulation may play a role in tumor dissemination.
Department of Orthopedic Surgery, Gunma University School of Medicine, Japan.
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H
Watanabe
T
T
Shinozaki
A
A
Raz
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M
Chigira
D000818:Animals; D000911:Antibodies, Monoclonal; D002465:Cell Movement; D003470:Culture Media; D005354:Fibrosarcoma / Q000378:metabolism / Q000473:pathology*; D066298:In Vitro Techniques; D008175:Lung Neoplasms / Q000556:secondary; D008562:Membrane Glycoproteins / Q000502:physiology; D051379:Mice; D008809:Mice, Inbred C3H; D009362:Neoplasm Metastasis; D060285:Receptors, Autocrine Motility Factor; D011956:Receptors, Cell Surface / Q000502:physiology*; D018121:Receptors, Cytokine; D014407:Tumor Cells, Cultured; D044767:Ubiquitin-Protein Ligases
D000911:Antibodies, Monoclonal; D003470:Culture Media; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; D018121:Receptors, Cytokine; C555002:Amfr protein, mouse; D060285:Receptors, Autocrine Motility Factor; D044767:Ubiquitin-Protein Ligases