Abstract:
Malignant melanoma is the most aggressive and life-threatening skin cancer with
increasing incidences over the past decades. Despite accounting for only 4 % of all skin
cancers, melanoma confers 80 % of skin cancer induced death. The underlying cause of
melanoma progression and metastasis is poorly understood.
Myc is a very strong proto-oncogene and it is very upregulated in many types of
cancers. c-Myc protein is a transcription factor that activates expression of many genes. It
drives cell proliferation, plays a very important role in regulating cell growth, apoptosis and
differentiation. High c-Myc expression is associated with tumor metastasis and poor
prognosis in human melanoma.
Full-length c-Myc is converted into Myc-nick by calcium-dependent on cytosolic
proteases that are members of the calpain family. In connection with the key role of the
cytoplasmic protein Myc-nick in the autophagy activativation, increasing the resistance to
chemotherapy and overall survival of tumor cells, it can be a target for treatment tumors under the conditions of c-Myc overexpression. That fact that the expression of Myc-nick increases
the survival of cells after UV radiation can indicate the key role of the Myc-nick in
tumorogenesis of melanoma cells.
