Tag Archives: apoptosis
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.