Experimental Oncology, 2011 (том 33)

Differential expression of PKD1 and PKD2 in gastric cancer and analysis of PKD1 and PKD2 function in the model system

2018-06-20T00:11:21Z

Differential expression of PKD1 and PKD2 in gastric cancer and analysis of PKD1 and PKD2 function in the model system Shabelnik, M.Yu.; Kovalevska, L.M.; Yurchenko, M.Y.; Shlapatska, L.M.; Rzepetsky, Yu.; Sidorenko, S.P. Aim: To study the differential expression of PKD1 and PKD2 in primary gastric cancer samples and to examine the role of PKD1 and PKD2 protein kinases in regulation of gastric tumor cell biology in the model system. Methods: Tumor samples of different histological variants of primary gastric cancer were analyzed. PKD1 and PKD2 expression levels in tumor samples were accessed by Western blot analysis and quantitative polymerase chain reaction (Q-PCR). As a model system we have used gastric adenocarcinoma сell line AGS sublines constitutively transfected by pcDNA3.1 coding PKD1 or PKD2, or empty pcDNA3.1 vector. These cell lines were analyzed by Western blot, Q-PCR, MTT and proliferation assays, in vitro scratch and Transwell assays, clonogenic assay. Results: It was found that primary gastric tumors possess different levels of PKD1 and PKD2 expression on mRNA and protein levels. Low level of PKD1 expression on protein and mRNA level was detected in low differentiated adenocarcinoma and ring cell gastric cancer — disorders with poor clinical prognosis. The high level of PKD2 expression was also found in gastric tumors with poor prognosis: low differentiated adenocarcinoma and adenogen cancer. To find out whether differential expression of PKD1 and PKD2 could affect biology of gastric tumor cells in vitro, we used a model system based on AGS cell line that constitutively expressed PKD1 or overexpressed PKD2. PKD1 transfection led to the inhibition of cell proliferation, migration and colony formation, in the meanwhile, the PKD2 overexpression enhanced proliferation, migration and colony formation capacities of AGS cells. Conclusions: Our data suggest that both downregulation of PKD1 or upregulation of PKD2 expression may determine the behavior of gastric tumor cells, which promotes invasive phenotype and could result in general poor prognosis.

Analysis of relative telomere length and apoptosis in humans exposed to ionising radiation

2018-06-20T00:10:46Z

Analysis of relative telomere length and apoptosis in humans exposed to ionising radiation Ilyenko, I.; Lyaskivska, O.; Bazyka, D. Background: Ionizing radiation could modify lymphocyte function via oxidative damage, DNA breaks, and resulting changes of proliferation, apoptosis and cellular senescence, where telomeres may play a critical role. Aim: To study the effect of low-dose irradiation on the telomere length and apoptosis rates in peripheral blood lymphocytes of irradiated persons. Patients and Methods: A study was performed on 83 peripheral blood samples from the Chornobyl clean-up workers, radiation workers exposed under the professional limits at construction works at the “Shelter” object and healthy controls. Bone marrow leukocyte telomere length was estimated in 15 patients with myelodysplastic syndrome secondary to low-dose radiation exposure and 12 age-standardized healthy donors. Relative telomere length was studied by the combination of a fluorescence hybridization in situ with PNA probe and flow cytometry, apoptosis — by Annexin-V test. Results: A significant relative telomere length decrease has been demonstrated in Chornobyl clean-up workers compared to healthy donors (13.2 ± 0.69 and 18.6 ± 0.73 respectively, p < 0.05), and a tendency (p < 0.1) in radiation workers. At doses over professional limits an inverse dependency is demonstrated between the relative telomere length and a number of lymphocytes in early stage of apoptosis. In MDS group a tendency of telomere elongation was demonstrated in bone marrow granulocytes in RAEB-t and RAEB as comparing with RA. Conclusion: This study shows telomere shortening after low-dose irradiation and preservation of these changes even 20 years after exposure. Apoptosis induction is possible by the telomere region changes at least in individuals with shorter telomeres. Apoptosis decrease in MDS clonal transformation is associated with a substantially longer telomeres.

Cooperative antitumor effect of endothelial-monocyte activating polypeptide II and flutamide on human prostate cancer xenografts

2018-06-20T00:09:55Z

Cooperative antitumor effect of endothelial-monocyte activating polypeptide II and flutamide on human prostate cancer xenografts Reznikov, A.G.; Chaykovskaya, L.V.; Polyakova, L.I.; Kornelyuk, A.I.; Grygorenko, V.N. Recombinant cytokine-like endothelial monocyte-activating polypeptide II (EMAP II) and antiandrogen flutamide target different mechanisms of growth of androgen-dependent prostate cancer (PC). The aim of this study was to clarify whether combined treatment with EMAP II and flutamide is more effective than monotherapy with regard to retardation of PC progression. Materials and Methods: Antitumor effects of EMAP II (10 µg/kg b.w./d, s.c., 3d), or flutamide (10 mg/kg b.w./d, per os, 3d), or their combination were studied in CBA male mice bearing human androgen-dependent PC xenografts for 7 days. Androgen-dependent phenotype of the tumors was verified in preliminary castrated mice. The xenografts were weighed and underwent a histopathologic examination. The results were compared with those of non-treated mice. Results: EMAP II and flutamide used separately inhibited growth of the xenografts by 74% and 53% respectively. Both drugs caused destructive changes in malignant epithelial cells along with leukocyte infiltration of the tumor. Combined treatment inhibited tumor growth by 85%, and was more effective than monotherapy with regard to morphological changes. Conclusions: This study demonstrates cooperative inhibitory effect of EMAP II and flutamide on growth and morphology of human PC xenografts that could represent a new modality of palliative treatment of this disease.

The influence of sodium dichloroacetate on the oxidative processes in sarcoma 37

2018-06-20T00:09:43Z

The influence of sodium dichloroacetate on the oxidative processes in sarcoma 37 Sorokina, L.V.; Pyatchanina, T.V.; Didenko, G.V.; Kaplia, A.A.; Khyzhnyak, S.V. Aim: to study the activity of antioxidant enzymes and to evaluate an intensity of prooxidant processes in sarcoma 37 (S37) cells during tumor development and under influence of sodium dichloroacetate (SDA). Methods: Activity of total superoxide dismutase (SOD), SOD isoforms, catalase (Cat), glutathione peroxidase (GP), and glutathione reductase (GR), as well as content of reduced glutathione (GSH) and lipid peroxidation (LP) secondary byproducts were determined in S37 homogenated tissues of untreated mice and animals treated with SDA at daily dose of 86 mg/kg. Results: SDA treatment of S37-bearing mice resulted in the reduced activities of total SOD, SOD isoforms (especially Mn-SOD), Cat, GP and significantly decreased GSH content on the background of LP intensification in tumor tissue. Conclusion: The observed changes of oxidative homeostasis in S37-bearing animals treated with SDA could be considered as an element of antitumor action of SDA.