The impact of RSUME in renal cell carcinoma cell metabolism being affected by VHL status

BELEN ELGUERO; MANUELA MARTINEFSKI; DAVID GOLNISKI; MARÍA ELENA KNOTT; LUCAS TEDESCO; JUAN MANUEL GUREVICH MESSINA; CORA POLLAK; MARÍA EUGENIA MONGE; EDUARDO ARZT

Conferencia Virtual

Simposio; 14th International VHL Medical/Research Symposium; 2020

https://www.vhl.org/researchers/clinical-trials-currently-progress/international-medical-research-symposium/

IntroductionThe kidney is frequently affected in patients with von Hippel-Lindau (VHL) disease. This organ can develop multiples tumors leading to repeated nephrectomies and, in some cases, may evolve to clear cell renal cell carcinoma (ccRCC). There is a need to improve clinicopathological markers to allow more accurate clinical decisions in renal tumor treatment. ccRCC is considered as a metabolic disease and characterized by accumulation of glycogen and lipids. Metabolic reprogramming in ccRCC is driven by HIF among other key regulators.RSUME or RWDD3 (RWD domain-containing protein SUMO Enhancer) is a hypoxia inducible protein isolated from highly tumorigenic and angiogenic cells and has been associated with poor prognosis in ccRCC. RSUME binds VHL protein and negatively regulates HIF degradation.MethodologyIn this study, we have investigated metabolic alterations triggered by RSUME in human ccRCC cell lines 786-O deficient for VHL (VHL−/−) and 3 stably clones with different expression of RSUME and VHL by means of ultraperformance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UPLC-QTOF-MS) combined with cross-validated multivariate statistical models. From panels of discriminant metabolites, we identified those with significantly different levels between cells with different RSUME and VHL statuses. These included amino acids, glutathione, butyrylcarnitine and acetylcarnitine. We further validated the impact of altered pathways associated to RSUME expression by biological experiments and bioinformatics analyses for glutathione and carnitines, respectively.ResultsRSUME-silenced 786-O cells showed a significant increase in glutathione levels compared to control cells, being 786-O shRSUME cells more affected than scramble cells to the oxidative challenges, supporting an alteration in the redox balance.By means of a bioinformatics approach conducted using the TCGA Kidney Renal Clear Cell Carcinoma (TCGA-KIRC) data collection, we identified reduced expression of Tricarboxylic Acid Cycle enzymes, higher expression of a key Fatty Acid Synthesis enzyme and reduced expression of Fatty Acid β-Oxidation enzymes in RSUME with higher expression in ccRCC patients, in agreement with the detected increased levels of acetylcarnitine and butyrylcarnitine in 786-O cells re-expressing VHL.Conclusion In this work, we report results from the first metabolic fingerprinting analysis of a ccRCC cell line in which RSUME is silenced in the presence and/or absence of VHL, supported by biological experiments and bioinformatics analysis. Combined results showed RSUME action on redox balance and fatty acid metabolism in ccRCC. These findings strengthen the RSUME participation in ccRCC tumors and further investigation could provide new opportunities for biomarker discovery and targeted therapies in VHL-kidney tumors.