Chemotaxis of metastatic tumor cells: clues to mechanisms from the Dictyostelium paradigm.

Amoeboid movement, and in some cases, amoeboid chemotaxis, is a key step in tumor metastasis. The high degree of conservation in signal transduction pathways and motile machinery in eukaryotic cells suggests that insights and molecular probes developed from the study of these processes in easily manipulated experimental model systems will be applicable directly to experimentally intractable tumor cells. One such model system, Dictyostelium discoideum, is discussed in terms of the molecular events involved in amoeboid chemotaxis. The application of insights and assays developed with Dictyostelium to early events in the chemotaxis of Lewis lung carcinoma cells is reviewed.