GM-CSF PRODUCTION IN HUMAN ADENOCARCINOMA CELL-LINES

We describe the production of human granulocyte-macrophage colony-stim ulating factor (hGM-CSF), by cell lines established from patients with different stages of breast, lung and colon adenocarcinoma. GM-CSF exp ression has been identified by immunocytochemistry determination, quan tified on conditioned medium with specific ELISA procedure and evaluat ed by means of proliferation and differentiation of normal human monoc ytic and granulocytic progenitors. The growth of cell lines after incu bation 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 brea st lung and colon adenocarcinoma and in 69 healthy person. Only two pa tients showed detectable GM-CSF levels. The lack of growth modulation observed in vitro with exogenous GM-CSF and antibody anti-GM-CSF sugge sts a non autocrine secretion by adenocarcinoma cells. The serum inves tigation evidences that the leukocytosis observed in adenocarcinoma pa tients is unrelated to a GM-CSF constitutive tumor production in vivo.