ZDHHC8-mediated β-catenin palmitoylation promotes WNT signaling activation and drives cisplatin resistance in osteosarcoma

Here, we identify the palmitoyltransferase ZDHHC8 as a critical determinant of cisplatin resistance and uncover a lipid modification–dependent mechanism that stabilizes β-catenin and sustains WNT signaling. ZDHHC8 expression was markedly upregulated in chemoresistant osteosarcoma tissues, and its knockdown significantly enhanced cisplatin-induced apoptosis both in vitro and in vivo.

Transcriptomic profiling and functional assays revealed that ZDHHC8 depletion suppressed WNT/β-catenin signaling and diminished cancer stem cell–like properties. Mechanistically, ZDHHC8 directly interacted with β-catenin and catalyzed its C381-specific palmitoylation, which prevented proteasomal degradation and maintained protein stability. Mutation of C381 abolished β-catenin palmitoylation, resulting in reduced WNT activity and impaired stemness maintenance.