Expression levels of FBXW7 and MDM2 E3 ubiquitin ligases and their c‑Myc and p53 substrates in patients with dysplastic nevi or melanoma

E3 ubiquitin ligases are of interest as drug targets due to their involvement in the regulation of the functions and interactions of several proteins. Various E3 ligase complexes are considered oncogenes or tumor suppressors associated with the development of melanoma. These proteins regulate the functions of various signaling pathways and proteins, such as p53 and Notch. The aim of the present study was to determine the expression levels of F-box and WD repeat domain-containing 7 (FBXW7), c-Myc, MDM2 and p53 proteins in samples from patients with dysplastic nevi or melanoma, and to evaluate their association with clinicopathological parameters and prognosis of the disease. Paraffin blocks with postoperative material from 100 patients diagnosed with dysplastic moles or melanoma were used in the present study. Tissue microarrays and immunohistochemistry were used to examine FBXW7, c-Myc, MDM2 and p53 protein expression. The results revealed that there was significantly lower FBXW7 expression in advanced melanoma compared with dysplastic nevus, melanoma in situ and stage pT1 melanoma (P