The role of chemerin in clear cell renal cell carcinoma

The most common subset of renal carcinoma, clear cell renal cell carcinoma (ccRCC), is characterized by accentuated accumulation of neutral lipids in lipid droplets and adipogenic trans-differentiation. Because obesity is a major risk factor in the development of ccRCC, we investigated the role of the adipokines in driving lipid metabolism and tumorigenesis in ccRCC. Through in silico screening, we identified the adipokine chemerin as candidate pro-oncogenic factor that is overexpressed in tumors and prognostic for patient outcome. Both ccRCC patient tumor tissues and serum exhibit elevated chemerin levels as compared to normal controls in an obesity-dependent manner. Attenuation of chemerin by several approaches in ccRCC cells led to significant impairments of tumor growth in both in vitro and in vivo models. A multi-omic approach revealed that chemerin suppresses fatty acid oxidation and maintains fatty acid levels which feed into transcriptional activation of hypoxia-inducible factor 2 (HIF2) expression. Suppression of chemerin therefore induced excess fatty acid oxidation and led to ferroptosis. CoQ and mitochondrial complex IV, derived mainly from lipid, were affected after chemerin inhibition, contributing to mitochondrial dysfunction and lipid reactive oxygen species production. Monoclonal antibody targeting chemerin led to reduced lipid storage, increased cell death, and diminished tumor growth, strengthening the translational potential of chemerin inhibition. Collectively, the results suggest that obesity and tumor cells contribute to ccRCC through the expression of chemerin, which is indispensable in ccRCC biology. mRNA profiling in experimental model of ccRCC 786-O cells. RARRES2 gene is deleted using lentiviral shRNA.