ZDHHC2-Mediated AGK Palmitoylation Activates AKT–mTOR Signaling to Reduce Sunitinib Sensitivity in Renal Cell Carcinoma

Tyrosine kinase inhibitors (TKI) that can suppress the VEGF signaling pathway and angiogenesis have been developed to impede the progression of malignant tumors and have been approved as first-line targeted agents for clear cell renal cell carcinoma (ccRCC). Dysregulation of lipid metabolism is a major driver of TKI resistance in renal cancer. In this study, we showed that the palmitoyl acyltransferase ZDHHC2 is abnormally upregulated in tissues and cell lines resistant to TKIs, such as sunitinib. Upregulation of ZDHHC2 contributed to sunitinib resistance in cells and mice, and ZDHHC2 regulated angiogenesis and cell proliferation in ccRCC. Mechanistically, ZDHHC2 mediated AGK S-palmitoylation to promote translocation of AGK into the plasma membrane and activation of the PI3K–AKT–mTOR signaling pathway in ccRCC, which modulated sunitinib sensitivity. In conclusion, these results identify a ZDHHC2–AGK signaling axis and suggest that ZDHHC2 is a targetable candidate for improving the antitumor efficacy of sunitinib in ccRCC. SIGNIFICANCE: ZDHHC2 confers sunitinib resistance to clear cell renal cell carcinoma by catalyzing AGK palmitoylation to activate the AKT–mTOR pathway.