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Saint Petersburg, United States

Yartseva N.M.,Institute of Cytology RAS | Fedortseva R.F.,Fsbi The Am Nikiforov Russian Center For Emergency And Radiation Medicine
Tsitologiya | Year: 2014

Neoplastic transformation of cells is characterized by karyotypic abnormalities involving aneuploidy, quantitative changes, as well as multiple clonal rearrangements of the number and structure of chromosomes. It is probable that chromosomes are one of the mechanisms of cells immortalization and transformation. Despite many years of study of chromosomal rearrangements, data on primary chromosomal rearrangements in early stages of transformation is still insufficient. We examined karyotypic abnormalities in embryonic rat fibroblasts in both the spontaneous transformation and transformation by oncogenes at different passages in vitro. Literature data and results of our cytogenetical analysis of rat cells lines established by different methods of transformation of cells of different tissue origin in vitro have shown that cell karyotype at early passages may either be normal or acquire diverse clonal chromosomal abnormalities. At later passages, other chromosomes of karyotype are involved in new rearrangements. Despite this, some of the lines do not acquire the malignant phenotype and remain to be immortalized. The role of instable chromosomes and their loci in immortalization and transformation of cells is discussed.

Pleskach V.A.,Institute of Cytology RAS | Kozhucharova I.V.,Institute of Cytology RAS | Alekseenko L.L.,Institute of Cytology RAS | Pleskach N.M.,Institute of Cytology RAS | And 2 more authors.
Tsitologiya | Year: 2011

Alloferon-1 (AF) and allostatin-1 (AS) cytotoxic and growth modulating activities have been compared. AF is cationic oligopeptide isolated from the hemolymph of experimentally infected blow fly Calliphora vicina. AS is AF synthetic analog that differs from the parent molecule in two amino acids substituted. It has been shown that both AF and AS have no direct cytotoxic activity in concentrations ranging from 1·10-5 to 10 μg/ml, however, the peptides demonstrated significant effect on tumor cells proliferation in vitro. Both peptides displayed growth modulating activity in mass cell cultures and boosted growth inhibiting activity of doxorubicin in the course of P388D1 cells cloning, although AS potentated doxorubicin cytostatic activity to a greater extent. Similarly, AS boosted anti-clonogenic activity of cyclophosphamide applied in a subthreshold concentration. Experiments with peptide-fluorescein complex have demonstrated that AF and AS belong to the group of cell-penetrating peptides. Moreover, the experiments displayed AF ability to bind with chromosomes.

Raydan M.,Institute of Cytology RAS | Shubin N.A.,Institute of Cytology RAS | Nikolayenko N.S.,Institute of Cytology RAS | Blinova M.I.,Institute of Cytology RAS | And 2 more authors.
Tsitologiya | Year: 2011

On the bases of earlier conducted research about the stability of heterogeneous population of keratinocytes to low temperatures according to their stages of differentiation this experiment' studies in vitro the stability to low temperatures of rat bone marrow stromal cells before and after their adipocyte and osteocyte differentiation. Results show that bone marrow stromal cells after their differentiation into either adipocytes or octeocytes became least stable to low temperatures. Findings may serve as foundation for further studies that may explain the changes of processes and mechanisms that play a major role in BMSC stability to low temperatures according to their stage of differentiation.

Yurinskaya V.E.,Institute of Cytology RAS | Rubashkin A.A.,Institute of Cytology RAS | Shirokova A.V.,Institute of Cytology RAS | Vereninov A.A.,Institute of Cytology RAS
Tsitologiya | Year: 2011

Time course of changes in intracellular water, K+ and Na+ of U937 cells incubated in hyperosmolar medium with addition of 200 mM sucrose was studied. Ouabain-sensitive and ouabain-resistant Rb+ (K+) influxes were measured during regulatory cell volume increase (RVI) and apoptotic volume decrease (AVD). Microscopy of cells stained by Acrydine orange, Ethydium bromide, APOPercenrage Dye and polycaspase marker FLICA was performed. We found that initial osmotic cell shrinkage induced both RVI and AVD responses. RVI dominated at the early stage whereas AVD prevailed at the later stage. In view of the data obtained in U937 cells the current opinion that RVI «dysfunction» is a prerequisite for apoptosis and AVD (Subramanyam et al., 2010) should be revised. U937 cells are capable to trigger of apoptosis and AVD in spite of the unimpaired RVI response. It is concluded that AVD plays a significant role in preventing osmotic lysis of apoptotic cells rather than in the initiation of apoptosis.

Salova A.V.,Institute of Cytology RAS | Leontieva E.A.,Institute of Cytology RAS | Mozhenok T.P.,Institute of Cytology RAS | Kornilova E.S.,Institute of Cytology RAS | And 2 more authors.
Tsitologiya | Year: 2011

The study of changes in the intracellular processes during differentiation of myoblasts into myotubules is of great importance for understanding several fundamental problems of cell biology. At first, this concerns the spatial organization of vacuolar apparatus that reflects the alterations in the properties of cell membranes, cytoskeleton elements and dynamics of vesicular transport in the course of differentiation. The distribution of acidic membrane organelles (lysosomes, late endosomes, Golgi cisternae) during the myotubule formation was revealed. It was shown that perinuclear localization of acidic organelles in myoblasts was replaced by diffuse distribution of these structures in the whole volume of myotubules. Using lipophilic fluorescent dyes, RH 414 and di-8-ANEPPS, the process of formation and dynamics of endocytic vesicles in myoblasts and myotubules was investigated. In the present work, semiconductive nanocrystals, quantum dots (QDs), conjugated with TAT-peptide, which belongs to cell-penetrating peptides, were used to characterize nonspecific endocytosis. It was shown that QDs-TAT complexes penetrate myoblasts but do not penetrate myotubules even after 24 h incubation, which might be connected with plasma membrane changes during the process of skeletal muscle differentiation.

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