GM-CSF production in human adenocarcinoma cell lines

We describe the production of human granulocyte-macrophage colony-stimulating factor (hGM-CSF), by cell lines established from patients with different stages of breast, lung and colon adenocarcinoma. GM-CSF expression has been identified by immunocytochemistry determination, quantified on conditioned medium with specific ELISA procedure and evaluated by means of proliferation and differentiation of normal human monocytic and granulocytic progenitors. The growth of cell lines after incubation with exogenous GM-CSF and antibody-antiGM-CSF was not modified. To better understand the patho-physiologic role of hGM-CSF in vivo we also estimated its serum levels at diagnosis in 75 patients with breast lung and colon adenocarcinoma and in 69 healthy person. Only two patients showed detectable GM-CSF levels. The lack of growth modulation observed in vitro with exogenous GM-CSF and antibody anti-GM-CSF suggests a non autocrine secretion by adenocarcinoma cells. The serum investigation evidences that the leukocytosis observed in adenocarcinoma patients is unrelated to a GM-CSF constitutive tumor production in vivo.