Simultaneous production of G- and M-CSF by an oral cancer cell line and the synergistic effects on associated leucocytosis

We established a novel cell line, TSU, from a oral cancer patient with marked leucocytosis. The culture supernatant of TSU cells promoted granulocytic colony formation by mouse bone marrow cells, indicating that TSU produced granulocyte-colony stimulating factor (G-CSF). The concentration of G-CSF was 2.45 micrograms/mg protein, measured by enzyme-linked immunosorbent assay (ELISA). The maximum number of colonies induced by TSU culture supernatant was more than that achieved with recombinant human G-CSF (rhG-CSF) and the size of the colonies induced by TSU supernatant was obviously larger than those achieved with rhG-CSF. The activity of TSU supernatant was completely inhibited by antihuman G-CSF and macrophage-colony stimulating factor (M-CSF) antibodies, but was only partially inhibited by antihuman G- or M-CSF antibody alone. These results indicate that not only G-CSF but also M-CSF, both of which could be produced by TSU cells, are involved in causing leucocytosis; the results suggest that the synergistic production of G- and M-CSF could play an important role in the leucocytosis associated with oral cancer.