Targeting the SPC25/RIOK1/MYH9 Axis to Overcome Tumor Stemness and Platinum Resistance in Epithelial Ovarian Cancer.

In epithelial ovarian cancer (EOC), platinum resistance, potentially mediated by cancer stem cells (CSCs), often leads to relapse and treatment failure. Here, the role of spindle pole body component 25 (SPC25) as a key determinant promoting stemness and platinum resistance in EOC cells, with its expression being correlated with adverse clinical outcomes is delineated. Mechanistically, SPC25 acts as a scaffolding platform, orchestrating the assembly of an SPC25/RIOK1/MYH9 trimeric complex, triggering RIOK1-mediated phosphorylation of MYH9 at Ser1943.

Lysosomal cyst(e)ine storage potentiates tolerance to oxidative stress in cancer cells.

Cyst(e)ine is a key precursor for the synthesis of glutathione (GSH), which protects cancer cells from oxidative stress. Cyst(e)ine is stored in lysosomes, but its role in redox regulation is unclear. Here, we show that breast cancer cells upregulate major facilitator superfamily domain containing 12 (MFSD12) to increase lysosomal cyst(e)ine storage, which is released by cystinosin (CTNS) to maintain GSH levels and buffer oxidative stress.