Original Research CDCA2 promotes melanoma progression by inhibiting ubiquitin-mediated degradation of Aurora kinase A

Background: Malignant melanoma is one of the most aggressive types of malig-nant skin cancer. CDCA2 is of great significance in many tumours, but its role in melanoma is unclear. Methods: CDCA2 expression in melanoma samples and benign melanocytic naevus tissues was detected by GeneChip and bioinformatics analysis as well as immunohistochemistry. The gene expression in melanoma cells was detected by quantitative PCR detecting system and Western blot. Melanoma models with gene knockdown or overexpression were constructed in vitro, and the effects of gene knockdown or overexpression on melanoma cell phenotype and tumour growth were evaluated by celigo cell counting, transwell, wound healing, flow cyto-metry and subcutaneous nude mouse tumour models. GeneChip primeview, Ingenuity pathway analysis and bioinformatics analysis combined with co-immunoprecipitation, protein stability experiments and ubiquitination analysis were performed to demonstrate the down-stream genes and regulatory mechanism of CDCA2. Results: CDCA2 was highly expressed in melanoma tissues, and CDCA2 level was positively correlated with tumour stage and poor prognosis. CDCA2 downregulation significantly re-duced cell migration and proliferation by inducing G1/S phase arrest and apoptosis. CDCA2 knockdown suppressed tumour growth and Ki67 expression in vivo. Mechanistically, CDCA2 inhibited ubiquitin-dependent Aurora kinase A (AURKA) protein degradation by acting on SMAD specific E3 ubiquitin protein ligase 1. AURKA downregulation inhibited melanoma cell proliferation and migration and promoted apoptosis. High expression of AURKA im-plied poor survival in melanoma patients. Moreover, AURKA knockdown constricted CDCA2 overexpression-induced proliferation and migration. Conclusion: CDCA2, which was upregulated in melanoma, enhanced AURKA protein sta-bility by inhibiting SMAD specific E3 ubiquitin protein ligase 1-mediated AURKA ubiqui-tination, thus playing a carcinogenic role in melanoma progression. (c) 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).