Klin Onkol 2016; 29(5): 347-350. DOI: 10.14735/amko2016347.
Background: Malignant melanoma is one of the most aggressive types of cancers. Melanoma is derived from pigment-producing cells, melanocytes, which are characterized by a specific survival mechanism. Microphthalmia-associated transcription factor (MITF-M) plays a role in the metabolism of melanoma and is involved in the regulation of the expression of multiple genes mediating processes such as melanogenesis, proliferation, differentiation, and melanocyte survival. The expression of this transcription factor in melanocytes is activated by several signaling pathways, and reduced expression or function of MITF-M can cause the dysregulation of anti-apoptotic mechanisms. MITF-M is also involved in matrix metalloproteinase 14 (MMP14) activity, which is responsible for shape changes in melanocytes and increases in their motility and invasiveness. Very low levels of expression of MITF-M are found in human melanocytes with an invasive phenotype, indicating that this transcription factor acts as a suppressor of the metastatic process. Cancer cells with low expression of cytosolic/nuclear β-catenin have a small amount of MITF-M 14 that is insufficient to inhibit MMP transcription. The enzyme catalyzes the degradation of laminin and fibronectin, thereby changing the shape of melanocytes, which leads to their increased mobility and invasiveness. Aims: This review describes the regulatory pathway of MITF-M activation, its involvement in the proliferation of transformed melanocytes, and its role in increasing the invasiveness of malignant melanoma. A detailed understanding of the MITF-M signaling pathway is highly topical and could help to develop new diagnostic and therapeutic applications for patients with malignant melanoma.
