ROLE OF SIRTUIN 1 IN REGULATION OF MELANOMA CELL PROLIFERATION

Melanoma remains one of the most dangerous skin cancers among fair-skinned population. the search for new effective treatments, including therapy based on the selection of molecular targets, is one of the main and difficult tasks in the study of melanoma. One of the trends in experimental oncology is the study of microRNa’s role in carcinogenesis. MicroRNas are involved in many physiological and pathological processes, including cell proliferation, differentiation, migration, invasion, and carcinogenesis. It has been previously revealed that miR-204-5p levels are reduced in malignant tumors, in particular, in skin melanoma. the aim of this study was to determine the functional role of sIRt1 as a direct target of miR-204-5p in the pathogenesis of skin melanoma. Bioinformatics analysis allowed identification of micrRNa target genes that affected apoptosis, proliferation and cell viability. the level of proliferation of melanoma cells under the influence of small interfering RNa was estimated using the Mtt test and fluorescence microscopy. Luciferase Reporter assay was performed to evaluate whether sIRt1 was a target of miR-204-5p. Relative luciferase activity was calculated 48 hours after transfection with miR-204-5p mimic. the Mtt test showed that the proliferative activity of melanoma cells decreased 72 hours after siRNa sIRt1 knockdown. Fluorescent microscope revealed the same tendency in sIRt1 siRNa transfected cells. Mechanistic studies revealed that miR-204-5p repressed the expression of sIRt1 through binding to its 3`utR. therefore, miR-204-5p can regulate melanoma cell proliferation by targeting sIRt1 which can affect intercellular signaling systems related to cell cycle

p-CoOx/n-SnO2 nanostructures: New highly selective materials for H2S detection

Nanostructures p-CoOx/n-SnO2 based on tin oxide nanowires have been prepared by two step CVD technique and characterized in detail by XRD, XRF, XPS, HAADF-STEM imaging and EDX-STEM mapping. Depending on the temperature of decomposition of cobalt complex during the second step of CVD synthesis of nanostructures cobalt oxide forms a coating and/or isolated nanoparticles on SnO2 nanowire surface. It was found that cobalt presents in +2 and +3 oxidation states. The measurements of gas sensor properties have been carried out during exposure to CO (14 ppm), NH3 (21 ppm), and H2S (2 ppm) in dry air. The opposite trends were observed in the effect of cobalt oxide on the SnO2 gas sensitivity when detecting CO or NH3 in comparison to H2S. The decrease of sensor signal toward CO and NH3 was attributed to high catalytic activity of Co3O4 in oxidation of these gases. Contrary, the significant increase of sensor signal in the presence of H2S was attributed to the formation of metallic cobalt sulfide and removal of the barrier between p-CoOx and n-SnO2. This effect provides an excellent selectivity of p-CoOx/n-SnO2 nanostructures in H2S detection. (C) 2017 Elsevier B.V. All rights reserved