Lysosomotropic cationic drugs induce cytostatic and cytotoxic effects: Role of liposolubility and autophagic flux and antagonism by cholesterol ablation.
Cation trapping in acidic cell compartments determines an antiproliferative effect that has a potential interest in oncology, as shown by clinical data and trials involving chloroquine and hydroxychloroquine. To further characterize the mechanism of this effect, we studied a series of 6 substituted triethylamine (s-Et3N) drugs that encompasses a wide range of liposolubility (amiodarone, quinacrine, chloroquine, hydroxychloroquine, lidocaine, and procainamide). Three tumor cell lines and primary human endothelial cells were exploited in proliferation assays (48h, cell counts). Accumulation of the autophagic effector LC3 II and the apoptotic marker cleaved PARP1 (immunoblots), cytotoxicity, cell cycle analysis and endocytic function were further tested in the p53-null histiocytic lymphoma U937 line. A profound and desynchronized antiproliferative effect was observed in response to all s-Et3Ns with essentially no cell type specificity. Predictors of s-Et3N potency were liposolubility and the acute accumulation of the autophagic effector LC3 II (6h-treatments). For each s-Et3N, there was an antiproliferative concentration range where cytotoxicity and apoptosis were not triggered in U937 cells (24-48h-treatments). Quinacrine was the most potent cytostatic drug (1-5μM). Co-treatment of cells with inhibitors of cholesterol, β-cyclodextrin or lovastatin, partially reversed the antiproliferative effect of each s-Et3N. The cytopathology induced by cationic drug accumulation includes a cytostatic effect. Its intensity is cell type- and p53-independent, but predicted by the inhibition of autophagic flux and by the liposolubility of individual drugs and alleviated by cholesterol ablation. The superiority of quinacrine, biomarker value of LC3 II and antagonism by a statin may be clinically relevant.
Axe Maladies Infectieuses et Immunitaires, CHU de Québec-Université Laval, Québec, QC G1V 4G2, Canada.
Alexandre
A
Parks
Axe Maladies Infectieuses et Immunitaires, CHU de Québec-Université Laval, Québec, QC G1V 4G2, Canada. Electronic address: francois.marceau@crchul.ulaval.ca.
François
F
Marceau
D000638:Amiodarone / Q000494:pharmacology; D000924:Anticholesteremic Agents / Q000494:pharmacology*; D001343:Autophagy / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D002738:Chloroquine / Q000494:pharmacology; D002784:Cholesterol / Q000378:metabolism*; D054697:Cytostatic Agents / Q000494:pharmacology*; D003603:Cytotoxins / Q000494:pharmacology*; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D006886:Hydroxychloroquine / Q000494:pharmacology; D008012:Lidocaine / Q000494:pharmacology; D008148:Lovastatin / Q000494:pharmacology*; D008247:Lysosomes; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D000071137:Poly (ADP-Ribose) Polymerase-1 / Q000378:metabolism; D011342:Procainamide / Q000494:pharmacology; D011796:Quinacrine / Q000494:pharmacology; D047392:beta-Cyclodextrins / Q000494:pharmacology
D000924:Anticholesteremic Agents; D054697:Cytostatic Agents; D003603:Cytotoxins; C477012:MAP1LC3A protein, human; D008869:Microtubule-Associated Proteins; D047392:beta-Cyclodextrins; D006886:Hydroxychloroquine; D002738:Chloroquine; D002784:Cholesterol; D008012:Lidocaine; D008148:Lovastatin; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011796:Quinacrine; C031215:betadex; D011342:Procainamide; D000638:Amiodarone
Antiproliferative effect; Autophagic flux; Cation trapping; Lysosomotropic drugs; Quinacrine