Studies on nude mice bearing human CSF-producing tumor. III. Colony type of granulocyte-macrophage precursors of nude mice bearing CSF-producing tumor.

In previous studies, we analyzed the hemopoietic precursor cells of tumor-bearing nude mice with marked neutrophilia induced by a transplanted human lung cancer. In this study, we examined the morphology of granulocyte-macrophage colonies using a technique for cytochemical examination of all colonies grown in agar gel culture. By stimulation with spleen cell-conditioned medium, the bone marrow cells and spleen cells of tumor-bearing nude mice formed a higher proportion of granulocyte-containing colonies than those of control mice. However, a larger number of granulocyte-macrophage progenitors were not definitely committed to differentiate into granulocytes and macrophages, as no significant differences in cellular composition of colonies between tumor-bearing mice and control mice were observed by stimulation with L cell-conditioned medium.