Effect of Microtubule Inhibitors on Invasion and on Related Activities of Tumor Cells

Abstract

Invasion marks the onset of malignancy in solid tumors. A consequence of invasion is metastasis leading to the death of the host in many cases. Microtubule inhibitors disturb the equilibrium of microtubule assembly/disassembly and, therefore, interfere with the structure and function of the mitotic spindle and of the cytoplasmic microtubule complex. In addition, immunocytochemistry with antibodies against tubulin—the building block of microtubules—is the method of choice to evaluate the status of microtubule complexes inside cells. Microtubule inhibitors arrest invasion of malignant cells in organ culture and in vivo . This chapter reviews the data about the effect of microtubule inhibitors (MTIs) on invasion, on directional migration, and on other cellular activities that are possibly involved in invasion. It discusses the hypothesis that MTIs inhibit tumor invasion because they interfere with directional migration through disturbance of the cytoplasmic microtubule complex (CMTC). Biochemical experiments (in the test tube), experiments with cultured cells ( in vitro ), and experiments using whole organisms ( in vivo ) are described.