Invasion of tumor cells is an important step for metastasis and is governed by several sub-

cellular processes. A number of them a_ect the contractivity, by which we describe the

ability of the cancer cells to adapt their shape and orientation according to the surround-

ing tissue. We derive a multiscale model focusing on the inuence of the cell contractivity

on tumor cell migration. It takes into account both the subcellular level, where changes of

contractivity are initiated, and the macroscopic level of the cell population. We provide

the local existence of a unique solution in a general framework, prove the global existence

of solutions for a slightly more speci_c setting and present numerical simulations to illus-

trate the e_ect of contractivity on the migration of cancer cells in our model. These are

joint works with G. Meral (Zonguldak), C. Surulescu (Kaiserslautern) and M. Winkler

(Paderborn).