SUMO switches metastasis on and off
Nature Cell Biology doi: 10.1038/ncb1415
New players in the process of metastasis of cancer cells are described in a paper in the June issue of Nature Cell Biology. Sung Hee Baek and colleagues also present a novel means of controlling proteins that direct metastasis. Metastasis is the process by which cancer cells spread from the primary tumour to form secondary tumours at other locations in the body. Understanding how this process is controlled will be instrumental to developing new therapeutic approaches for treating metastatic cancer. The team had previously shown that a protein called reptin is important for shutting down expression of KAI1, a gene that blocks metastasis. In their new study, the authors report that when another protein called SUMO becomes attached to reptin, it switches reptin's function so that it turns off KAI1 expression. This is because SUMO promotes the interaction of reptin with other proteins that can shut down KAI1 expression. Removal of SUMO from reptin, on the other hand, activates KAI1 expression. They also found that interfering with the attachment of SUMO to reptin changes the metastatic ability of tumour cells. This study reveals new factors that control metastasis and could potentially be targets for therapeutic intervention.
