In vivo and in vitro biological activities of two human cell lines derived from anaplastic lung cancers.
Overview
abstract
Cell lines Lu-65 and SK-Luci-6 were established from two patients with anaplastic (non-oat cell) lung cancers. These cell lines showed in vivo and in vitro functional activities that could explain the paraneoplastic syndromes which were clinically manifested. In both patients, elevated white blood cell counts occurred in the absence of any evidence of sepsis. Tumor fragments taken directly from one patient and transplanted to nude mice produced a progressive leukocytosis in the mice. Tissue culture-derived cells from both cell lines enhanced white blood cell numbers following heterotransplantation to nude mice. Cell-free extracts from both cell lines were found to enhance granulocyte-macrophage colony formation in soft agar. Greater colony formation was consistently found with the cell line (SK-Luci-6) that was derived from the patient manifesting the more marked leukocytosis. These data suggest that the tumor cells release colony-stimulating activities. Coincidently, one cell line (Lu-65) synthesized and released large amounts of prostaglandin E2 with little or no other prostaglandin product; the other cell line produced no prostaglandins. When the tumor cell lines were cocultured with explanted fetal rat bones, enhanced bone resorption with excessive calcium release occurred. Bone-resorbing activity correlated with tumor prostaglandin synthesis for the cell line releasing prostaglandin E2. An osteolytic factor that was neither prostaglandin nor parathyroid hormone was released by the SK-Luci-6 cell line. Hypercalcemia was a persistent feature only in the patient from whom the latter tumor line was derived.
