Doxorubicin induces apoptosis in Jurkat cells by mitochondria-dependent and mitochondria-independent mechanisms under normoxic and hypoxic conditions. Issue 6 (July 2015)

• Record Type: Journal Article
• Authors: Mendivil-Perez, Miguel; Velez-Pardo, Carlos; Jimenez-Del-Rio, Marlene
• Is Part Of: Anti-cancer drugs. Volume 26:Issue 6(2015)
• Publication Date: 2015-07
• Subjects: Antineoplastic agents -- Periodicals; Cancer -- Chemotherapy -- Periodicals; Antineoplastic Agents -- therapeutic use -- Periodicals; Drug Therapy -- Periodicals; 616.994061
• DOI: 10.1097/CAD.0000000000000223
• Languages: English
• ISSNs: 0959-4973

Abstract

<abstract> <title> <x xml:space="preserve">Abstract</x> </title> <sec> <p>In this study, we investigated the molecular mechanism of doxorubicin (dxr)-induced cytotoxicity on Jurkat cells – a model cell of human acute lymphoblastic leukemia – under normoxic (20% O<sub>2</sub>) and hypoxic (5% O<sub>2</sub>) conditions. Using in-cell western analysis, immunofluorescence, flow cytometry analysis, and biochemical inhibitors, we evaluated several oxidative stress (OS) and cell death markers. It was found that dxr (5–100 μmol/l) induced apoptosis by OS mechanisms involving DNA fragmentation (8–48%), loss of mitochondrial membrane potential (ΔΨ<sub>m</sub>, 33–92%), and H<sub>2</sub>O<sub>2</sub> production (15–42%) under normoxia. In addition, dxr (10 μmol/l) induced activation and/or nuclei translocation of NF-κB (6.6, 1.6-fold increase), p53 (4.3, 3.1 f), c-Jun (9.5, 5.0 f), apoptosis-inducing factor (AIF) (1.9, 3.9 f), caspase-3 (3.7, 1.9 f), overexpression of Parkin (2.1, 1.2 f)/PINK-1 (2.1 f) proteins, and reduced DJ-1 levels by half compared with untreated cells under normoxia, according to immunofluorescence and in-cell western analysis, respectively. In contrast, dxr (10 μmol/l) could not induce apoptosis in Jurkat cells under hypoxia. Effectively, dxr significantly reduced DNA fragmentation (6%), expression levels of cell death (e.g. p53, c-Jun, caspase-3, AIF), and OS (e.g. Parkin) markers, whereas it increased ΔΨ<sub>m</sub>, hypoxia-inducible factor 1-α (HIF-1α, 3.1, 2.3 f), NF-κB (6.8, 2.0 f), and DJ-1 (1.3, 1.0 f) levels. This investigation suggests that dxr might efficiently eliminate acute lymphoblastic leukemia cells by OS-induced apoptosis under normoxic conditions through a minimal completeness of cell death signaling (i.e. mitochondria–caspase-3/AIF-dependent pathways) and through a direct DNA damage process. However, hypoxic conditions may reduce the effectiveness of dxr toxicity.</p> </sec> </abstract>