Viability and mitochondrial bioenergetic functions in human colon cancer cells are not affected by treatment with peptides mtCPP1, UPF25, mtgCPP, and mtCPP1gHO

Abstract

The popularity of the specially synthesized cell-penetrating peptides (CPPs) in cancer treatment has grown recently. The main aim of this study was to investigate the effects of four mitochondrially targeted antioxidant CPPs on the viability and bioenergetic function of mitochondria in human adenocarcinoma Caco-2 cells. The number of viable cells was measured by MTT and trypan blue assays. Respirometry and the permeabilized cell technique were applied to measure the mitochondrial function in this cell line. We did not observe any significant effect of CPPs on the mitochondrial reserve respiratory capacity, the function of respiratory chain complexes, and the inclination of these cancer cells to aerobic glycolysis. mtgCPP peptide with the highest antioxidant activity demonstrated improved mitochondrial coupling efficiency. CPPs do not affect mitochondrial function directly but can be considered in therapeutics as a drug-delivery moleculeCompeting Interest StatementThe authors have declared no competing interest.Abbreviations usedAKadenylate kinase;Ap5Adiadenosine pentaphosphate;CATcarboxyatractyloside;CRCcolorectal cancer;CPPscell-penetrating peptides;HKhexokinase;FAM5-(6)-carboxyfluorescein;MTT3-(4,5-dimethylthiazolyl-2)-2, 5-diphenyltetrazoliumbromide;OXPHOSoxidative phosphorylation;ROSreactive oxygen species;TMPDN,N,N’,N’-tetramethyl-phenylenediamine;VDACvoltage dependent anion channel.View Full Text