A paraneoplastic syndrome of hypercalcemia and leukocytosis associated with solid tumors: production of interleukin 1 alpha (IL-1 alpha) and granulocyte colony-stimulating factor (G-CSF) by clonal squamous cell carcinoma cells.

We have demonstrated that T3M-1 cells and T3M-5 cells, derived from squamous carcinomas of patients with leukocytosis and hypercalcemia, produced excessively G-CSF, IL-1 alpha and a small amount of PTH-like factor. We confirmed that G-CSF and IL-1 alpha (hemopoietin 1) enhanced granulocytopoiesis and caused marked leukocytosis in vivo. Furthermore, we also demonstrated that PTH-rP and IL-1 alpha (a potent osteoclast-activating factor) synergistically stimulated bone resorption in vitro and also synergistically increased serum calcium concentration in vivo. Since we have demonstrated that at least two clonal cell lines derived from patients with hypercalcemia and leukocytosis produced G-CSF and IL-1 alpha, we presume that hypercalcemia and leukocytosis associated with some solid tumors may constitute a new paraneoplastic syndrome.