Overexpression of sprouty 2 inhibits HGF/SF-mediated cell growth, invasion, migration, and cytokinesis.

A strict regulation of hepatocyte growth factor/scatter factor (HGF/SF)-Met signaling is essential for its appropriate function. Several negative regulators of Met signaling have been identified. Here we report that human Spry2 is induced by HGF/SF and negatively regulates HGF/SF-Met signaling. We show that overexpression of Spry2 inhibits cell proliferation, anchorage-independent cell growth, and migration in wound-healing and in vitro invasion assays. Measured in an electric cell-substrate impedance sensing biosensor, cell movement is restricted, because Spry2 dramatically facilitates cell attachment and spreading by enhancing focal adhesions and increasing stress fibers. An analysis of cell cycle distribution shows, unexpectedly, that Spry2-GFP cells are polyploid. Thus, as with FGF and EGF receptors, Spry2-GFP tempers downstream Met signaling in addition to its pronounced effect on cell adhesion, and it has properties suitable to be considered a tumor-suppressor protein.