Palmitoyltransferase ZDHHC8 drives clear cell renal cell carcinoma progression by regulating the FOXA2–ceruloplasmin axis and tumor angiogenic microenvironment

Protein palmitoylation is an important post-translational modification involved in tumor progression, but its role in kidney renal clear cell carcinoma (KIRC) remains insufficiently understood. This study aimed to identify oncogenic ZDHHC family members in KIRC and clarify the biological significance of their downstream regulatory network. Transcriptomic and clinical data from TCGA, GEO, ArrayExpress, and ICGC cohorts were integrated to evaluate the expression and prognostic relevance of ZDHHC family genes in KIRC. Candidate downstream targets were screened through intersection analyses. Single-cell RNA sequencing and spatial transcriptomics were used to determine the cellular distribution and spatial localization of key molecules. CellChat and PySCENIC analyses were performed to infer intercellular communication patterns and upstream transcriptional regulation. Functional validation was conducted using qPCR, Western blotting, ELISA, ABE assay, proliferation and migration assays, intracellular metal ion detection, and cell-derived allograft experiments. ZDHHC8, ZDHHC11, ZDHHC16, ZDHHC18, and ZDHHC22 were upregulated in KIRC and associated with poor prognosis. Among their potential downstream effectors, ceruloplasmin (CP) showed the most consistent oncogenic relevance, and its regulation was strongest for ZDHHC8. ZDHHC8 and CP were coordinately elevated in KIRC tissues and cells, while pharmacological inhibition of palmitoylation or ZDHHC8 silencing reduced CP expression and secretion. Single-cell and spatial transcriptomic analyses showed that CP-high expression was enriched in a specific malignant epithelial subpopulation and co-localized with ZDHHC8 in tumor niches. CellChat analysis revealed enhanced pro-angiogenic signaling from CP-high malignant cells to endothelial cells. Mechanistically, ZDHHC8-dependent palmitoylation of FOXA2 at C247 was required for FOXA2 binding to the CP promoter and for CP transactivation, as directly demonstrated by ChIP-qPCR and CP-promoter luciferase reporter assays using wild-type and palmitoylation-deficient (C247A) FOXA2. Functionally, silencing ZDHHC8 or CP suppressed tumor cell proliferation and migration, altered intracellular Fe²⁺ and Cu⁺ homeostasis, and enhanced the antitumor efficacy of sunitinib in vivo. ZDHHC8 may act as an oncogenic palmitoyltransferase in KIRC and could promote tumor progression by regulating the FOXA2-CP axis, copper homeostasis, and pro-angiogenic microenvironment remodeling. Targeting this pathway may represent a potential strategy warranting further preclinical validation for combination therapy in KIRC.