OTUD4 regulates metastasis and chemoresistance in melanoma by stabilizing Snail1

Melanoma is the most aggressive form of skin cancer with rapidly increased incidence worldwide especially in the Caucasian population. Surgical excision represents the curative treatment choice in patients with early-stage disease. However, the therapeutic outcomes in patients with metastatic melanoma remains unsatisfactory. Thus, understanding molecular mechanisms contributing to metastasis and chemoresistance is critical for new improved therapies of melanoma. Snail1, an important epithelial-mesenchymal transition transcription factors (EMT-TFs), is critical to induce the EMT process, thereby contributing to cancer metastasis. However, the involvement of Snail1 in melanoma metastasis remains elusive and the underlying mechanism to regulate Snail1 in melanoma needs to be further investigated. Here, we identified OTUD4 as a novel deubiquitinase of Snail1 in melanoma. Moreover, the depletion of OTUD4 in melanoma cells markedly inhibited Snail1 stability and Snail1-driven malignant phenotypes both in vitro and in vivo. Overall, our study establishes OTUD4 as a novel therapeutic target in metastasis and chemoresistance of melanoma by stabilizing Snail1 and provides a rationale for potential therapeutic strategies of melanoma.