RSUME ACTS ON PRIMARY CILIA IN RENAL CARCINOMA DEVELOPMENT

DAVID GONILSKI PACIN; NICOLÁS CIANCIO DEL GIUDICE; FLORENCIA HERBSTEIN; SERGIO SENIN; MANUEL FIZ; MARIA COTARELO; PATRICIO YANKILEVICH; MARIANA FUERTES; EDUARDO ARZT

Mar del Plata

Congreso; LXVIII Reunión Anual de la Sociedad Argentina de Investigación Clínica; 2023

Sociedad Argentina de Investigación Clínica (SAIC)

RSUME, the product of the RWD domain containing 3 (RWDD3) gene, is involved in tumor angiogenesis, and its expression has been reported in organs prone to develop von Hippel-Lindau (VHL) syndrome tumors. RSUME acts as a negative regulator of VHL protein function in normoxia promoting Hypoxia-inducible factor alpha (HIF-α) stabilization. VHL ubiquitinates Aurora kinase A (AURKA) to control primary cilia formation, and VHL loss produces primary cilia disassembly and, in turn, renal cancer development. To deepen the mechanisms of RSUME action in clear cell Renal Cell Carcinoma (ccRCC), we first performed a Gene set enrichment analysis (GSEA) to compare RSUME high and low expression samples in five independent datasets with ccRCC tumor transcriptomic data.ccRCC tumor samples were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. We observed that cilium related pathways are enriched in tumors with a higher expression of RSUME (NES > 2; p < 0.001; FDR < 0.02), indicating that primary cilium could be a target of RSUME action on ccRCC. To validate RSUME molecular action in cilium pathway we used 10 genetically modified RCC cell lines generated in our laboratory, lacking endogenous VHL (RCC-786-O VHL-/-) expressing wild type VHL or different VHL mutants (VHL-Tyr112His, -Arg167Gln, -Leu188Val), combined with shRSUME or its scrambled control. By WB, we tested in these cell lines whether RSUME modulates AURKA levels. We demonstrate that in VHL absence or VHL wild type or VHL mutants’ presence, RSUME silencing diminishes AURKA protein levels. To evaluate if RSUME and AURKA interact and participates in the same protein complex we performed immunoprecipitation assays, which show that RSUME and AURKA interact in a protein complex. RSUME regulation and interaction with AURKA may contribute to its action on ccRCC kidney disease development.