The chemotactic response of tumor cells. A model for cancer metastasis.

Injection of a C5-derived chemotactic factor for tumor cells into the peritoneal cavities of Sprague-Dawley rats induced diffuse mesenteric metastasis following the intravenous injection of Walker carcinosarcoma cells. Intraperitoneal injections of culture medium, histamine, or of trypsin-treated albumin resulted in many fewer metastases. Intraperitoneal injections of the chemotactic factor, unlike histamine, did not alter mesenteric vasopermeability as measured by the exudation of Evans blue into the mesentery. In vitro, tumor cells responded to the chemotactic factor by demonstrating directed migration in the Boyden chamber, by volume changes, measurable in the Coulter counter, and by demonstrating an increased adherence to nylon fibers. These phenomena are similar to the behavior of neutrophils in the presence of their chemotactic factors. All the responses in vitro were markedly depressed by the addition of 2-deoxyglucose, while the cell swelling response was slightly enhanced by cytochalasin B (again similar to the responses of leukocytes). The data suggest that movement of tumor cells from the circulation may be under chemotactic influence in the manner similar to the responsiveness of neutrophils to leukotactic stimuli in vivo.