The lack of a proper cell matrix attachment leads to an anoikis like state and drives selleck chemical these cells into apoptosis. Activa tion of growth factor receptors, however, can both protect the cells from apoptosis and induce migration in a three dimensional collagen environment. Most migrat ing cells express either membrane bound or secreted matrix metalloproteases at the cell front that digest the matrix and open space for the forward pushing cell body. MMPs are commonly upregulated after growth factor stimulation. Although the best studied targets of these proteases are various matrix components, a grow ing body of evidence reveals the importance of MMP dependent cleavage of other extra and intracellular sub strates that have various cellular effects.

Here, we take advantage of the well defined transform ing abilities of the oncogene xmrk and use it as model to analyze the cancer inducing functions of receptor tyro sine kinases. Inhibitors,Modulators,Libraries In order to concentrate on RTK driven effects alone without influences from secondary tumor derived effects we are using Xmrk expressing mel anocytes rather than melanoma cells. Activa tion of Xmrk leads to transformation of these cells and induces key features of the neoplastic phenotype of melanoma cells. One of these key features is the occurrence of dedifferentiation, which can be directly visualized by decresed pigmentation and reduced tyrosine levels after Xmrk activation. Besides dedifferentia tion Inhibitors,Modulators,Libraries and unlimited proliferation, Xmrk has been pre viously reported to induce cellular migration of melanocytes in a two dimensional migration assay and mediate cell survival in three dimensional collagen lattices.

In this study, we investigated the three dimensional migration behaviour. We found that Xmrk activation induced melanocyte migration in an amoeboid manner which is entirely independent of MMP activity. Instead, blocking MMPs with a broadband inhibitor Inhibitors,Modulators,Libraries mix stalled cell proliferation. The Inhibitors,Modulators,Libraries protease responsible for the proliferation effect was MMP13, as demonstrated by RNA knockdown experiments. Importantly, MMP13 was also found to be necessary for the proliferation of the human melanoma cell line A375. Results EGF stimulation of melanocytes leads to MAPK and PI3K independent migration on collagen To monitor the effects of signalling of the oncogenic RTK Xmrk we used HERmrk transgenic melanocytes that transgenically express a chimeric protein consisting of an extracellular EGFR and an intracellular Xmrk domain.

It is important to note that these cells do not express endogenous EGFR. The chimeric receptor displays the same intracellular Inhibitors,Modulators,Libraries signal ling as Xmrk and in addition allows EGF induction instead selleck of permanent activation. To find out which matrix components are suitable for migration of melan a Hm we first performed a modified Boyden chamber assay on transwell inlays that were either left uncoated or were precoated with vitronectin, fibronectin, or col lagen I.