In a new Swedish study, researchers at Umeå University have identified a key protein called Snail1, which appears to be crucial to the spread of prostate cancer cells.  You can read the original article here: “Researchers Uncover Key Molecular Process that Leads to Prostate Cancer Metastasis.”

The finding could lead to new therapies that block these metastatic cells.  Metastasis is the process in which cancer cells travel through the body from the tumor site to secondary locations and form new/additional tumors.  The molecular mechanisms behind metastasis are not fully understood, however, some features of the metastatic cells are already known. For example, in order for cancer cells to spread, they must undergo a process called epithelial-to-mesenchymal transition (EMT.)  This is when an epithelial cell loses its ability to do cell-to-cell adhesion, and becomes invasive and migratory.  Cytokine transforming growth factor B (TGFB) can prompt EMT by activating the Snail1 protein, but exactly how this happens had not been previously understood.

After being made, many proteins undergo process called post-translational modifications (PMTs), which further regulate the functions performed by the proteins.  One of these PMT’s, known as sumoylation, is when a small protein called SUMO is added to a protein to regulate its function.  The researchers found that when the Snail1 protein is modified in prostate cancer cells through sumoylation, this resulted in the cells becoming more invasive by enhancing TGFB signaling and EMT.  Thus, when sumoylation was inhibited, the prostate cancer cells lost their invasive ability.  The Swedish researchers concluded that the sumoylation of Snail1 might be a marker for prostate cancer progression.