SHPS-1: a budding molecule against cancer dissemination.

The expression of SHPS-1 is down-regulated by several oncogene products such as v-Src in fibroblasts. In addition, the down-regulation of SHPS-1 is also found inhuman breast cancer tissues compared with the matched normal tissues. On the other hand, forced expression of SHPS-1 suppresses anchorage-independent cell growth of v-Src-transformed cells in vitro as well as peritoneal dissemination of the cells in nude mice. Surprisingly, the extracellular region (EC) of SHPS-1 seems to take part on the inhibitory effect. Because the EC domain interacts with fibronectin and DTT abrogates the inhibitory effects of the EC, we speculate that super-fibronectin may function with the EC as a suppressor of cancer cells. Here we show that SHPS-1 expression provides a unique potential that links suppression of anchorage-independent cell growth and cancer dissemination.