SKP2 in Cancer: From Molecular Regulation to Therapeutic Vulnerabilities and Translational Perspectives.

The ubiquitin-proteasome system (UPS) plays a central role in regulating protein homeostasis and degradation. Its dysregulation is closely associated with various diseases, including cancer. S-phase kinase-associated protein 2 (SKP2) is a key E3 ubiquitin ligase component of the UPS. It induces proteasome-mediated protein degradation or modulates substrate function by conjugating K48-linked or K63-linked ubiquitin chains to diverse target proteins. Recent studies have shown that the overexpression of SKP2 in several cancer types is correlated with poor clinical outcomes, underscoring its potential as a therapeutic target. Notably, emerging evidence has expanded the functional repertoire of SKP2 beyond cell cycle control to encompass metabolism, DNA repair, stemness, tumor microenvironment (TME) and immunotherapy response, positioning it as an increasingly attractive target for intervention. In this review, the oncogenic properties of SKP2 and its underlying mechanisms were elucidated in multiple cancer types. Moreover, we systematically summarized future directions for SKP2-targeted therapy.