title: Detailed analysis of apoptosis and delayed luminescence of human leukemia Jurkat T cells after proton irradiation and treatments with oxidant agents and flavonoids.
abstract: Following previous work, we investigated in more detail the relationship between apoptosis and delayed luminescence (DL) in human leukemia Jurkat T cells under a wide variety of treatments. We used menadione and hydrogen peroxide to induce oxidative stress and two flavonoids, quercetin, and epigallocatechin gallate, applied alone or in combination with menadione or H(2)O(2). 62 MeV proton beams were used to irradiate cells under a uniform dose of 2 or 10 Gy, respectively. We assessed apoptosis, cell cycle distributions, and DL. Menadione, H(2)O(2) and quercetin were potent inducers of apoptosis and DL inhibitors. Quercetin decreased clonogenic survival and the NAD(P)H level in a dose-dependent manner. Proton irradiation with 2 Gy but not 10 Gy increased the apoptotic rate. However, both doses induced a substantial G(2)/M arrest. Quercetin reduced apoptosis and prolonged the G(2)/M arrest induced by radiation. DL spectroscopy indicated that proton irradiation disrupted the electron flow within Complex I of the mitochondrial respiratory chain, thus explaining the massive necrosis induced by 10 Gy of protons and also suggested an equivalent action of menadione and quercetin at the level of the Fe/S center N2, which may be mediated by their binding to a common site within Complex I, probably the rotenone-binding site.
authors: Department of Biophysics, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania. baran@ifin.nipne.ro
authors: Irina
authors: I
authors: Baran
authors: Constanta
authors: C
authors: Ganea
authors: Simona
authors: S
authors: Privitera
authors: Agata
authors: A
authors: Scordino
authors: Vincenza
authors: V
authors: Barresi
authors: Francesco
authors: F
authors: Musumeci
authors: Maria Magdalena
authors: MM
authors: Mocanu
authors: Daniele F
authors: DF
authors: Condorelli
authors: Ioan
authors: I
authors: Ursu
authors: Rosaria
authors: R
authors: Grasso
authors: Marisa
authors: M
authors: Gulino
authors: Alexandru
authors: A
authors: Garaiman
authors: Nicolò
authors: N
authors: Musso
authors: Giuseppe A Pablo
authors: GA
authors: Cirrone
authors: Giacomo
authors: G
authors: Cuttone
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects*; D002392:Catechin / Q000031:analogs & derivatives / Q000494:pharmacology; D002453:Cell Cycle / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002999:Clone Cells; D005419:Flavonoids / Q000494:pharmacology*; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D019169:Jurkat Cells; D007700:Kinetics; D007938:Leukemia / Q000473:pathology*; D049449:Luminescence; D009249:NADP / Q000378:metabolism; D016877:Oxidants / Q000633:toxicity*; D011522:Protons; D011789:Quantum Theory; D011794:Quercetin / Q000494:pharmacology; D013997:Time Factors; D024483:Vitamin K 3 / Q000633:toxicity
chemical_list: D005419:Flavonoids; D016877:Oxidants; D011522:Protons; D009249:NADP; D024483:Vitamin K 3; D002392:Catechin; D011794:Quercetin; D006861:Hydrogen Peroxide; C045651:epigallocatechin gallate