Tag Archives: apoptosis
Rhamnazin inhibits proliferation and induces apoptosis of human jurkat leukemia cells in vitro
А. А. Philchenkov, М. P. Zavelevych
R. E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology,
National Academy of Sciences of Ukraine, Kyiv;
e-mail: apoclub@i.ua
Antiproliferative and apoptogenic effects of rhamnazin, a dimethoxylated derivative of quercetin, were studied in human acute lymphoblastic leukemia Jurkat cells. The cytotoxicity and apoptogenic activity of rhamnazin in vitro are inferior to that of quercetin. The apoptogenic activity of rhamnazin is realized via mitochondrial pathway and associated with activation of caspase-9 and -3. The additive apoptogenic effect of rhamnazin and suboptimal doses of etoposide, a DNA topoisomerase II inhibitor, is demonstrated. Therefore, methylation of quercetin modifies its biological effects considerably.
Biological effects of thyroid hormones
T. S. Saatov, A. A. Abduavaliev
Institute of Bioorganic Chemistry, Uzbekistan Academy of Sciences, Tashkent;
e-mail: t.saatov@yandex.ru
The article presents the findings from the study on multifunctional effects of thyroid hormones in relation to normal and malignantly transformed tissues and cells. Both “rapid” and «slow» effects of thyroid hormones including calorigenic effects and effects over adenylate cyclase – cAMP system have been described. Thyroxin (Т4) has been established capable to inhibit proliferation and to induce apoptosis of cells carrying Т4 receptors on their membranes as well as to change course of metabolic processes under its effect. Spectrum of Т4 targets is quite broad to include not only cells of hormone-producing organs, to name those of the breast and the colon, but also other types of cells to name melanin-containing ones; Т4 effects resulting in reconstruction of presentation of regulatory proteins on the cell membrane surface to ultimately activate the process of cell apoptosis. Our findings help determine alternative paths for hormonal regulation of cell proliferation and apoptosis of cells of hormone-dependent tumors, breast cancer, in particular, upon impossibility to regulate the processes by conventional methods. This facilitates understanding mechanisms for activation of signal system of the breast cancer’s cells by hormones upon changes in expression of receptors on the cells’ surface, making possible development of novel strategy for replacement therapy of hormone-dependent tumors upon low efficacy of drug therapy.
Sweet taste of cell death: role of carbohydrate recognition systems
R. Bilyy, R. Stoika
Institute of Cell Biology, National Academy of Sciences of Ukraine, Lviv;
e-mail: r.bilyy@nas.gov.ua; stoika@cellbiol.lviv.ua
This paper describes a complicated way how the glycoepitops’ alterations on a surface of dying cells allow investigators to decipher specific mechanisms underlying cell restructuring at apoptosis. These glycoepitops are important at removal of fragments of dying cells from the body, which can be a cause of formation of the auto-antibodies.
The role of reactive oxygen species in tumor cells apoptosis induced by landomycin A
L. V. Lehka1, R. R. Panchuk1, W. Berger2, Ju. Rohr3, R. S. Stoika1
1Institute of Cell Biology, National Academy of Sciences of Ukraine, Lviv;
2Institute of Cancer Research, Medical University of Vienna, Austria;
3Department of Pharmaceutical Sciences, University of Kentucky, USA;
e-mail: lilyalehka@gmail.com
Landomycin A (LA) is a new antitumor antibiotic of angucycline group, possessing high antitumor activity against cancer cells of different origin, which induces early apoptosis in target cells. It was shown that under LA action the level of reactive oxygen species (ROS) in human T-leukemia cells had increased 5.6 times in comparison to control already at the 1st hour after the addition of studied antibiotic to the culture medium. At the 6th hour after incubation of cells with LA the nucleosomal DNA cleavage, chromatin condensation and nucleus fragmentation were observed, indicating apoptotic cell death. Catalase (scavenger of hydrogen peroxide), mannitol (scavenger of hydroxyl radicals) and superoxide dismutase (scavenger of superoxide radicals) reduced the level of ROS production under LA, suggesting the generation of H2O2, OH• and O2– radicals, respectively. It was revealed that catalase and mannitol effectively inhibited LA-mediated tumor cell death, increasing 2.5 times the percentage of alive cells in comparison to LA. However, superoxide dismutase had no significant inhibitory effect on cytotoxic activity of LA, indicating the minor role of superoxide anions in the implementation of antitumor activity of this antibiotic. Combination of catalase, mannitol and superoxide dismutase with LA increased 4-fold the percentage of alive cells in comparison to the action of LA. Dynamics of ROS formation confirms that the increase of ROS is a very rapid process, but at the same time it is not a direct consequence of apoptosis triggering, mediated by mitochondria.
Action of free and polymer carrier encapsulated doxorubicin towards HCT116 cells of human colorectal carcinoma
Yu. V. Senkiv1,2,4, P. Heffeter2, A. O. Riabtseva3, N. M. Boiko1,
O. S. Zaichenko3, N. Ye. Mitina3, W. Berger2, R. S. Stoika1
1Institute of Cell Biology, National Academy of Sciences of Ukraine, Lviv;
2Institute for Cancer Research, Medical University of Vienna, Austria;
3National University Lviv Polytechnic, Ukraine;
4Ivan Franko Lviv National University, Ukraine;
e-mail: stoika@cellbiol.lviv.ua
Development of novel nanoscale functionalized carriers is nowadays one of the most urgent problems in cancer treatment. The aim of our study was to compare the antineoplastic effect of free doxorubicin and its complex with a nanoscale polymeric carrier towards HTC116 colorectal carcinoma cells. It was established that application of the complex of poly(5-tret-butylperoxy)-5-methyl-1-hexene-3-in-co-glycydyl metacrylat)-graft-polyethyleneglycol (poly(VEP-GMA-PEG)-graft-PEG), where VEP – 5-tret-butylperoxy)-5-methyl-1-hexene-3-in; GMA – glycydyl metacrylat; graft-PEG – graft-polyethyleneglycol accordingly, functionalized with phosphatidylcholine for doxorubicin delivery increased 10 times the efficiency of cytotoxic action of this drug, as compared wich such efficiency in case of the action of free doxorubicin. The encapsulated form of doxorubicin caused more intensive cleavage of the reparation enzyme PARP and longer delay in G2/M cell cycle arrest, compared to such effects of free doxorubicin. The developed carrier itself is non-toxic to the used mammalian cells and does not cause impairment in their cell cycle. A deletion in both alleles of p53 gene did not affect the antineoplastic action of doxorubicin that was immobilized on the nanoscale carrier. Thus, p53-dependent signaling pathways are not involved in the cytotoxic action of doxorubicin-carrier complex. It is suggested that novel nanoscale polymeric carrier poly(VEP-GMA-PEG)-graft-PEG functionalized with phosphatidylcholine could be a promising carrier for targeted delivery of anticancer drugs.
Biochemical effects of combined action of γ-irradiation and paclitaxel on anaplastic thyroid cancer cells
V. M. Pushkarev, O. I. Kovzun, V. V. Pushkarev, M. D. Tronko
State Institution V. P. Komisarenko Institute of Endocrinology and Metabolism,
National Academy of Medical Sciences of Ukraine, Kyiv;
e-mail: pushkarev.vm@gmail.com
The aim of the paper was to describe the biochemical effects of Paclitaxel (Ptx), γ-irradiation (IR) and their combination in undifferentiated thyroid cancer cells (ATC). IR activated common DNA damage-induced signaling and manifested certain mitogenic effect by inactivation of retinoblastoma protein (pRb). There was clear antagonism between Ptx and IR relative to cell cycle regulators – tumor suppressor p53, pRb, CHK2 and c-Abl as well as proapoptotic Bax expression, but combined action of both agents enhanced caspase-3 and, especially, caspase-8 activation. The Ptx at low (1-25 nM) concentrations caused noticeable radioprotective effect.
Thus, in ATC cells the ionizing radiation and Ptx exhibited competitive effects upon phosphorylation of cell cycle controllers: p53, pRb, CHK2, cAbl and expression of Вах. At the same time, the combined effect of radiation and Ptx enhanced antiapoptotic Bcl-2 phosphorylation, caspases activation and survivin expression. The net effect of these events during the first 48-72 h of cells incubation can be considered as antiapoptotic – Ptx attenuated cytotoxic effect of IR.
Inhibitor of the transcription factor NF-κB, DHMEQ, enhances the effect of paclitaxel on cells of anaplastic thyroid carcinoma in vitro and in vivo
V. V. Pushkarev1, D. V. Starenki2, V. M. Pushkarev1,
O. I. Kovzun1, M. D. Tronko1
1State Institution V. P. Komisarenko Institute of Endocrinology and Metabolism,
National Academy of Medical Sciences of Ukraine, Kyiv;
e-mail: pushkarev.vm@gmail.com;
2Department of Biochemistry, Medical College of Wisconsin, USA;
e-mail: dstarenki@mcw.edu
Anticancer drug paclitaxel (Ptx) effect on biochemical mechanisms, regulating apoptosis in anaplastic thyroid carcinoma cells, was studied. It was shown that in addition to apoptotic cell death, Ptx induces signaling cascades that ensure cell survival. Paclitaxel-induced activation of nuclear factor kappa B (NF‑κВ) leads to an increase of some antiapoptotic proteins expression such as survivin, cIAP, XIAP. A novel NF‑κВ inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), was found to enhance cytotoxic effect of Ptx in anaplastic thyroid carcinoma cells. An enhancement of caspase-3 and -9 activation and PARP cleavage as well as the decreased levels of proteins-inhibitors of apoptosis were observed when cells were treated with a combination of both drugs. Mitochondria transmembrane potential (ΔΨm) loss was observed at higher concentrations of Ptx and DHMEQ. NF-κВ inhibition also potentiates paclitaxel effect at tumors formed by xenotransplantation of FRO cells into mice. Tumor mass reduction, significantly different from the effects of each of the compounds alone, was observed in animals, treated with paclitaxel and NF-κВ inhibitor. Thus, the combined use of paclitaxel and NF-κВ inhibitor inhibits biochemical processes that contribute to the resistance of anaplastic thyroid carcinoma cells to paclitaxel action.
Multiple molecular forms of adaptor protein Ruk/CIN85 specifically associate with different subcellular compartments in human breast adenocarcinoma MCF-7 cells
B. O. Vynnytska-Myronovska1, Ya. P. Bobak1, G. V. Pasichnyk2,
N. I. Igumentseva1, A. A. Samoylenko2, L. B. Drobot2
1Institute of Cell Biology, National Academy of Sciences of Ukraine, Lviv;
2Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: drobot@biochem.kiev.ua
Ruk/CIN85 is a receptor-proximal ‘signalling’ adaptor that possesses three SH3 domains, Pro- and Ser-rich regions and C-terminal coiled-coil domain. It employs distinct domains and motifs to act as a transducer platform in intracellular signalling. Based on cDNA analysis, various isoforms of Ruk/CIN85 with different combination of protein-protein interaction domains as well as additional Ruk/CIN85 forms that are the products of post-translational modifications have been demonstrated. Nevertheless, there is no precise information regarding both the subcellular distribution and the role of Ruk/CIN85 multiple molecular forms in cellular responses. Using MCF-7 human breast adenocarcinoma cells and cell fractionation technique, specific association of Ruk/CIN85 molecular forms with different subcellular compartments was demonstrated. Induction of apoptosis of MCF-7 cells by doxorubicin treatment or by serum deprivation resulted in the system changes of Ruk/CIN85 molecular forms intracellular localization as well as their ratio. The data obtained provide a new insight into potential physiological significance of Ruk/CIN85 molecular forms in the regulation of various cellular functions.
Proapoptotic properties of total phytohemagglutinine and its individual isolectins in human cell culture 4BL
T. O. Kochubei, O. V. Maksymchuk, L. L. Маcewicz, О. O. Piven, L. L. Lukash
Institute of Molecular Biology and Genetics, National Аcademy of Sciences of Ukraine, Кyiv;
е-mail: kochubei2009@ukr.net
Phytohemagglutinine (PHA) is widely investigated lectin with mitogenic properties. Recently it was shown that PHA is not only cell proliferation inducer, but also has a toxic or cytostatic effect. However concentration dependence and molecular mechanisms of this effect are not enough investigated. To study proapoptotic properties of total phytohemagglutinine and its isolectins in human cell culture of not tumor origin 4BL we observed a change in the frequency of apoptotic cells in the tested cell culture under the influence of the total phytohemagglutinine and erythroagglutinin by the method of specific color luminescent dye. The activation of caspases-3 and -8 and induction of protein Bax expression under the influence of lectins were detected by Western blot analysis. It was revealed that erythroagglutinin induced apoptosis with the highest efficiency compared with leukoagglutinin and total phytohemagglutinine. The induction of apoptosis in human cell culture of not tumor origin 4BL is probably caused by activating caspase-dependent and mitochondrial signalling.