ZDHHC9-mediated KLF5 palmitoylation enhances the cAMP/PKA/CREB axis to promote colorectal cancer progression

S-palmitoylation, a reversible lipid-based post-translational modification, is notably elevated in colorectal cancer (CRC) due to common lipid metabolism disorders. It has been reported to play crucial roles in regulating membrane composition, cell proliferation, and metastasis in various malignancies such as pancreatic and breast cancers. However, its role in the progression of CRC remains poorly understood. ZDHHC9, a member of the palmitoyl transferase family, is significantly upregulated in CRC patients and correlates with poor prognosis. Knockdown of ZDHHC9 impairs CRC cell proliferation and migration both in vitro and in vivo. RNA sequencing revealed that ZDHHC9 depletion markedly downregulates the cAMP signaling pathway. Mechanistically, ZDHHC9 knockdown impairs ADCY4 activity by reducing S-palmitoylation of KLF5 at cysteine 438, thereby modulating the ZDHHC9/KLF5/ADCY4 axis and downstream cAMP/PKA/CREB signaling to influence CRC cell proliferation and migration. Our findings demonstrate that ZDHHC9 promotes CRC progression by regulating intracellular cAMP levels through KLF5 palmitoylation, providing a novel therapeutic perspective targeting palmitoylation in CRC. The mechanism diagram of this study. ZDHHC9 mediates palmitoylation of KLF5 at cysteine 438, thereby enhancing ADCY4 activity and increasing intracellular cAMP levels. This elevation in cAMP promotes PKA and phosphorylation of CREB, ultimately activating the cAMP/PKA/CREB signaling pathway, which contributes to the regulation of CRC cell proliferation, migration, and resistance to 5-FU. (Created with BioRender.com).