Establishment of large cell lung cancer cell lines secreting hematopoietic factors inducing leukocytosis and thrombocytosis.

We have established cell lines from a large cell carcinoma of the lung accompanied by marked granulocytosis and thrombocytosis, and have analyzed the factors with colony stimulating factor (CSF) activity produced by them. Analysis of the CSF activity present in the culture medium of the established cell lines demonstrated growth-stimulating activity on CMK cells, a human megakaryoblastic cell line and mouse bone marrow cells. A neutralization test with antibodies against G-, M- and GM-CSF indicated the stimulation for the proliferation of CMK and mouse bone marrow cells to be mediated partially by the CSFs. Furthermore, the measurement of GM-CSF and interleukin(IL)6 by enzyme-linked immunosorbent assay (ELISA) and northern blotting analysis indicated productions of G-, GM- and M-CSF and of IL6 from the cell lines but failed to exhibit IL3 gene expression. It is suggested that the cell lines could be of use in the study of CSFs and, also, that lymphokines act on leukocyte and platelet progenitor cells.