Research advancements regarding the relationship between FBXO2 and malignant tumors (Review).

The ubiquitin‑proteasome system (UPS) acts as a central regulator for a range of protein components, including ubiquitin, ubiquitin‑activating enzyme (E1), ubiquitin‑conjugating enzyme (E2), ubiquitin ligase (E3), the 26S proteasome and deubiquitinating enzyme. These components function in a coordinated manner to facilitate the repair and degradation of proteins. Among the ubiquitinating enzymes, in conjunction with E1‑activating enzymes and E2‑binding enzymes, it attaches to substrates and promotes the transfer of ubiquitin molecules to target proteins. The S‑phase kinase‑associated protein 1 (SKP1)‑Cullin‑F‑box (SCF) complex is one of the E3 ligases involved in cancer progression, and consists of four primary components: i) SKP1; ii) Cullin 1/coiled‑coil domain containing 53; iii) ring box protein 1/RING‑box 1/RING‑box protein HRT1; and iv) F‑box protein (FBP). Each FBP can recognize and bind to a different set of substrates, which determines the specificity of the targets of the SCF complex. In addition to being components of the SCF complex, FBPs participate in processes such as DNA replication, transcription, cell differentiation and cell death. F‑box protein 2 (FBXO2), a member of the human FBP family, functions as a subunit of FBP ubiquitin ligases and is highly expressed in the cytoplasm of eukaryotic cells. FBXO2 is highly expressed in various malignant tumors, and is closely associated with tumor cell proliferation, migration and invasion. The present review presents the composition of the UPS and FBP families and their roles in malignant tumors, with a focus on advancements in research into the relationships between FBXO2 and various malignant tumors, aiming to acquire a more profound understanding of their potential mechanisms in the development of malignant tumors and to offer novel ideas for tumor therapy.