JMJD6-DGAT1 Signaling Regulates Lipid Metabolism and Tumorigenesis in ccRCC

Clear cell renal cell carcinoma (ccRCC) represents a lethal disease and classically resistant to cytotoxic chemotherapy, highlighting the importance of identifying new therapeutic vulnerabilities. We performed a functional siRNA screening for all 2-oxoglutarate (2-OG)-dependent enzymes in ccRCC using 3-D soft agar colony formation assay, and combined with TCGA data, we identified Jumonji domain-containing 6 (JMJD6) as an essential gene for ccRCC tumorigenesis. Downregulation of JMJD6 abolished ccRCC colony formation in vitro and inhibited orthotopic tumor growth in vivo. Integrated analyses of ChIP-seq and RNA-seq identified that JMJD6 can transcriptionally regulate the expression of diacylglycerol O-acyltransferase 1 (DGAT1) by co-occupying the target gene promoter with H3K4me3. Downregulation of JMJD6 caused decreased expression of DGAT1 at both mRNA and protein level. Inhibition or depletion of DGAT1 induced decreased cell growth in vitro or inhibited tumor growth in vivo. Mechanistically, decreased DGAT1 caused decreased LD formation in ccRCC, while restoration of JMJD6 expression can restore DGAT1 level, and LD formation as well as cell growth. In summary, JMJD6 is essential for ccRCC lipid storage and tumorigenesis through a DGAT1-dependent signaling. Therefore, the JMJD6-DGAT1 axis serves as a potential therapeutic avenue for ccRCC. Overall design: RNA-seq of 786-O clear cell renal cell carcinoma cells before and after JMJD6 knockout with two different sgRNAs (sgRNA2 and sgRNA4) versus control sgRNAs. ChIP-seq of JMJD6 and H3K4me3 with respective inputs in 786-O clear cell renal cell carcinoma cells.