Snail promotes prostate cancer migration by facilitating SPOP ubiquitination and degradation

Prostate cancer (PCa) is the second leading cause of cancer-associated mortality in men. Speckle-type pox virus and zinc finger protein (SPOP), the most frequently mutated gene in PCa, functions as a tumor suppressor via degradation of cancer-promoting substrates. However, its upstream regulation in PCa metastasis remains poorly determined. Here, in a Snail-induced metastatic PCa model, we observed an accelerated degradation of SPOP protein in cells, which is crucial for the PCa migration and activation of the AKT signaling pathway. Mechanistically, we demonstrated that binding to Snail promoted SPOP ubiquitination and degradation. Moreover, the bric-a-brac/tramtrack/broad complex (BTB) domain of SPOP is turned out to be essential for Snail-mediated SPOP degradation. Thus, our findings reveal a post-translational level regulation of SPOP expression that facilitates the metastasis of PCa cells.