Parthenolide

USP10 is a critical deubiquitinating enzyme within the ubiquitin-specific protease family, playing multifaceted roles in cellular physiology and disease pathogenesis. Structurally composed of a G3BP1-interacting motif, a N-terminal domain (mediating most protein interactions), and a catalytic USP domain (residues 415-795, catalytic triad C424-H736-D751), USP10 regulates diverse cellular pathways by stabilizing key proteins through deubiquitination. It exhibits context-dependent functional duality, particularly in cancer: USP10 promotes tumorigenesis in various cancers (e.g., glioblastoma, esophageal, pancreatic, breast cancers) by stabilizing oncoproteins like CCND1, YAP1, HDAC7, and RUNX1, enhancing proliferation, metastasis, and immune evasion. Conversely, it suppresses tumors (e.g., NSCLC, CRC, thyroid cancer) by stabilizing tumor suppressors like p53, PTEN, and Axin1, inhibiting pathways such as Wnt/β-catenin. Beyond oncology, USP10 contributes to neurodegenerative diseases (neuroprotective in PD/ALS, neurotoxic in AD via Tau stabilization), viral immunity (inhibits SARS-CoV-2 infection), inflammatory responses, male reproduction, and metabolic/cardiovascular disorders. Its regulatory mechanisms include phosphorylation (e.g., by AMPK, AKT, ATM) controlling subcellular localization and activity, and ubiquitination via USP13. USP10's therapeutic significance drives inhibitor development (Spautin-1, D1, Wu-5, P22077, Parthenolide), though cross-reactivity within the USP family due to conserved catalytic domains remains a challenge. Novel strategies like PROTACs and engineered ubiquitin variants (UbVs) offer promise for future selective targeting of USP10 dysregulation in diverse diseases. A comprehensive understanding of its structure and context-specific functions is essential for exploiting its full therapeutic potential.

Skin melanoma is a potentially lethal cancer and ranks as the 17th most common cancer worldwide. Overcoming resistance to advanced-stage melanoma is a significant challenge in its treatment. Parthenolide (PAR) is recognized as a potent anticancer small molecule, yet its potential in treating melanoma is poorly investigated.

Our objective was to investigate the apoptotic and anti-metastatic properties of PAR against the A2058 melanoma cells in vitro.

This study employed various assays, such as cytotoxicity, apoptosis, cell cycle analysis, reactive oxygen species (ROS) production, mRNA expressions, western blotting, gelatin zymography, and scratch assay. The synergy between PAR and dacarbazine, a chemotherapy drug for treating skin cancer, was also assessed.

Our study revealed that PAR significantly reduced the viability of A2058 cancer cells, demonstrating greater potency against cancer cells compared to normal L929 cells (IC50: 20 μM vs. 27 μM after 24h). PAR increased ROS production, elevated mRNA expression of pro-apoptotic Bax and NME1 genes, and decreased expression of the MITF gene. PAR induced apoptosis and cell cycle arrest in A2058 cells, as evidenced by the increased proportion of cells in the late apoptotic phase and sub-G1 cell cycle arrest. MMP-2 and MMP-9 mRNA and protein expressions, gelatinase activity, and the migration of A2058 cells were also decreased by PAR, suggesting its potential to suppress cancer cell invasion.

These results, along with the synergic effect with dacarbazine, indicated that PAR may have the potential to be a therapeutic drug for melanoma by triggering apoptosis and suppressing invasion and migration.