The combination of adenosine deaminase inhibition and deoxyadenosine induces apoptosis in a human astrocytoma cell line. (January 2015)

• Record Type: Journal Article
• Authors: Garcia-Gil, Mercedes; Tozzi, Maria Grazia; Varani, Stefano; Della Verde, Lorenza; Petrotto, Edoardo; Balestri, Francesco; Colombaioni, Laura; Camici, Marcella
• Is Part Of: Neurochemistry international. Volume 80(2015)
• Page Start: 14
• Page End: 22
• Publication Date: 2015-01
• Subjects: Ac-IETD-pNA Ac-Ile-Glu-Thr-Asp-paranitroaniline -- ADA adenosine deaminase -- ADF human astrocytoma cell line -- Ado adenosine -- AdoK adenosine kinase -- dAdo deoxyadenosine -- dATP deoxyATP -- dCF deoxycoformycin -- DMEM Dulbecco's modified Eagle's medium -- DEVD-pNA Asp-Glu-Val-Asp-paranitroanilinine -- DMSO dimethylsulfoxide -- FBS foetal bovine serum -- IAP inhibitor of apoptosis proteins -- LDH lactic dehydrogenase -- MT-ROS MitoTracker Red CM-H2XROS -- MT-Green MitoTracker Green -- MTT 3-(4, 5-dimethyl-thiazol-2-yl)-2, 5-diphenyltetrazolium bromide) -- NDGA nordihydroguaiaretic acid -- NH2dAdo 5' amino-5'deoxyadenosine -- PBS phosphate buffered saline -- pNA paranitroanilinine -- ROS reactive oxygen species -- SH-SY5Y human neuroblastoma cell line -- TMRM tetramethylrhodamine methyl ester -- ΔΨm mitochondrial membrane potential; Adenosine deaminase -- Deoxycoformycin -- Human astrocytoma cell line -- Apoptosis -- Lactate production -- Baicalein; Neurochemistry -- Periodicals; Neurochemistry -- Periodicals; Neurochimie -- Périodiques; Neurochemistry; Periodicals; 612.804205
• DOI: 10.1016/j.neuint.2014.11.005
• Languages: English
• ISSNs: 0197-0186

Abstract

Highlights: Treatment with deoxycoformicin plus dAdo increases dATP and reduces ATP in ADF cells. Perturbation in adenylate pool, induced by ADA inhibition, affects glucose metabolism. Baicalein seems to protect ADA inhibited cells by affecting AdoK activity. ADA inhibition induces apoptosis by activation of initiator caspase-8. Abstract: Alterations in the functions of astrocytes contribute to the appearance of a variety of neurological pathologies. Gliomas, especially those of astrocytic origin, are particularly resistant to chemotherapy and are often characterized by a poor prognosis. Neuroblastoma is the tumour with the higher incidence in infants. Anticancer drugs can induce apoptosis and their cytotoxic effect is often mediated by this process. We have previously demonstrated that the combination of deoxycoformycin, a strong adenosine deaminase inhibitor, and deoxyadenosine is toxic for a human astrocytoma cell line. In fact, after 15 h of treatment, this combination increases both mitochondrial reactive oxygen species and mitochondrial mass, induces apoptosis as indicated by cytochrome c release from mitochondria and activation of caspase-3. These events are preceded by reduction in lactate release in the medium. In this work we demonstrate that after 8 h of incubation with deoxyadenosine and deoxycoformycin, caspase-8 is activated, mitochondrial mass increases and mitochondrial reactive oxygen species decrease. The addition of baicalein to the incubation medium reduces cell death and caspase-3 activity induced by deoxycoformycin and deoxyadenosine in combination. This protective effect is correlated to an increase of lactate released in the medium, a decrease in the intracellular levels of dATP, and an increase in ATP levels, as compared with the cells subjected to the treatment with deoxycoformycin and deoxyadenosine without any further addition. The effect of baicalein appears to be related to an inhibition of deoxyadenosine phosphorylation, rather than or in addition to the well known antioxidant activity of the compound. This work indicates that an astrocytoma cell line, reported to be resistant to mitochondria-dependent pathways of apoptosis, is indeed very sensitive to a manipulation affecting the balance of cellular purine metabolite concentrations. The same treatment is also cytotoxic on a neuroblastoma cell line, thus suggesting long term implications for cancer therapy