1. Interconnections between apoptotic and autophagic pathways during thiopurine-induced toxicity in cancer cells: the role of reactive oxygen species
- Author
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Malin Lindqvist Appell and Wiem Chaabane
- Subjects
0301 basic medicine ,Antimetabolites, Antineoplastic ,autophagy ,Programmed cell death ,Base Pair Mismatch ,Cellbiologi ,Biology ,Mitochondrion ,medicine.disease_cause ,6-thioguanine ,03 medical and health sciences ,0302 clinical medicine ,Cell Line, Tumor ,Mitophagy ,medicine ,Humans ,6-mercaptopurine ,Thioguanine ,Membrane Potential, Mitochondrial ,chemistry.chemical_classification ,Reactive oxygen species ,azathioprine ,apoptosis ,Autophagy ,Chloroquine ,Cell Biology ,Mitochondria ,Cell biology ,Oxidative Stress ,030104 developmental biology ,Oncology ,chemistry ,Apoptosis ,Caspases ,030220 oncology & carcinogenesis ,Cancer cell ,Reactive Oxygen Species ,Oxidative stress ,Signal Transduction ,Research Paper - Abstract
// Wiem Chaabane 1 , Malin Lindqvist Appell 1 1 Division of Drug Research, Department of Medical and Health Sciences, Linkoping University, SE-58183 Linkoping, Sweden Correspondence to: Malin Lindqvist Appell, email: Malin.lindqvist.appell@liu.se Wiem Chaabane, email: wiemchaabane27@hotmail.fr Keywords: 6-thioguanine, 6-mercaptopurine, azathioprine, autophagy, apoptosis Received: May 26, 2016 Accepted: September 15, 2016 Published: September 28, 2016 ABSTRACT Thiopurines (azathioprine, 6-mercaptopurine and 6-thioguanine) are a class of genotoxic drugs extensively used in the treatment of various illnesses including leukemia. Their underlying molecular mechanism of action involves the activation of apoptosis and autophagy but remains widely unclear. Here we present evidence that autophagy induction by thiopurines is a survival mechanism that antagonizes apoptosis and is involved in degrading damaged mitochondria through mitophagy. On the other hand, apoptosis is the main cell death mechanism by thiopurines as its inhibition prohibited cell death. Thus a tight interplay between apoptosis and autophagy controls cell fate in response to thiopurine treatment. Moreover, thiopurines disrupt mitochondrial function and induce a loss of the mitochondrial transmembrane potential. The involvement of the mitochondrial pathway in thiopurine-induced apoptosis was further confirmed by increased formation of reactive oxygen species (ROS). Inhibiting oxidative stress protected the cells from thiopurine-induced cell death and ROS scavenging prohibited autophagy induction by thiopurines. Our data indicate that the anticarcinogenic effects of thiopurines are mediated by complex interplay between cellular mechanisms governing redox homeostasis, apoptosis and autophagy.
- Published
- 2016