Microphthalmia-Associated Transcription Factor-Dependent Melanoma Cell Adhesion Molecule Activation Promotes Peritoneal Metastasis of Ovarian Cancer

Ovarian cancer (OvCa) is one of the leading causes of death due to its high metastasis rate to the peritoneum. Recurrent peritoneal tumors also develop despite the use of conventional platinum-based chemotherapies. Therefore, it is still important to explore the factors associated with peritoneal metastasis, as these predict the prognosis of patients with OvCa. In this study, we investigated the function of microphthalmia-associated transcription factor (MITF), which contributes to the development of melanoma, in epithelial ovarian cancer (OvCa). High MITF expression was significantly associated with a poor prognosis in OvCa. Notably, MITF contributed to the motility and invasion of OvCa cells, and specifically with their peri-mesothelial migration. In addition, MITF-positive cells expressed the melanoma cell adhesion molecule (MCAM/CD146), which was initially identified as a marker of melanoma progression and metastasis, and MCAM expression was regulated by MITF. MCAM was also identified as a significant prognostic factor for poor progression-free survival in patients with OvCa. Collectively, our results suggest that MITF is a novel therapeutic target that potentially promotes peritoneal metastasis of OvCa.