Clear cell renal cell carcinoma (ccRCC) has a poor prognosis despite novel biological targeted therapies. Tumor aggressiveness and poor survival may correlate with tumor grade at diagnosis and with complex metabolic alterations, also involving glucose and lipid metabolism. However, currently no grade-specific metabolic therapy addresses these alterations. Here we used primary cell cultures from ccRCC of low- and high-grade to investigate the effect on energy state and reduced pyridine nucleotide level, and on viability and proliferation, of specific inhibition of glycolysis with 2-deoxy-D-glucose (2DG), or fatty acid oxidation with Etomoxir. Our primary cultures retained the tissue grade-dependent modulation of lipid and glycogen storage and aerobic glycolysis (Warburg effect). 2DG affected lactate production, energy state and reduced pyridine nucleotide level in high-grade ccRCC cultures, but the energy state only in low-grade. Rather, Etomoxir affected energy state in high-grade and reduced pyridine nucleotide level in low-grade cultures. Energy state and reduced pyridine nucleotide level were evaluated by ATP and reduced 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) dye quantification, respectively. 2DG treatment impaired cell proliferation and viability of low-grade ccRCC and normal cortex cultures, whereas Etomoxir showed a cytostatic and cytotoxic effect only in high-grade ccRCC cultures. Our data indicate that in ccRCC the Warburg effect is a grade-dependent feature, and fatty acid oxidation can be activated for different grade-dependent metabolic needs. A possible grade-dependent metabolic therapeutic approach in ccRCC is also highlighted.
Oncotarget. 2017 Dec 08*** epublish ***
Cristina Bianchi, Chiara Meregalli, Silvia Bombelli, Vitalba Di Stefano, Francesco Salerno, Barbara Torsello, Sofia De Marco, Giorgio Bovo, Ingrid Cifola, Eleonora Mangano, Cristina Battaglia, Guido Strada, Giuseppe Lucarelli, Robert H Weiss, Roberto A Perego
School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy., Pathology Unit, ASST Monza, San Gerardo Hospital, Monza, Italy., Institute for Biomedical Technologies, National Research Council, Segrate, Italy., Department of Medical Biotechnology and Translational Medicine, University of Milano, Segrate, Italy., Urology Unit, ASST North Milan, Bassini Hospital, Cinisello Balsamo, Italy., Department of Emergency and Organ Transplantation-Urology, University of Bari, Bari, Italy., Division of Nephrology, Department of Internal Medicine, School of Medicine, and Cancer Center, University of California, Davis, CA, USA.