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Biomedical subjects

S G Zubova

Publications and source records attributed to S G Zubova.

10 recordsLinked to original sources
PubMed2005

[Induction of premature senescence program by an inhibitor of histone deacetylase sodium butyrate in normal and transformed rat fibroblasts].

We investigated a possibility to induce the premature cell senescence in rat embryo fibroblasts and E1A + cHa-ras transformants. We found that after the treatment with sodium butyrate, an inhibitor of histone deacetylases, both normal and transformed cells completely stopped to proliferate and accumulated at G1/S and G2/M phases of the cell cycle. The cloning efficiency data show that the cell cycle arrest induced by sodium butyrate is irreversible and correlates with the accumulation of active phosphorylated form of stress kinase p38, and with the expression of marker of senescence--beta-galactosidase activity (SA beta-Gal). The program resembling the premature senescence after sodium butyrate treatment is supposed to develop both in normal and transformed cells. The irreversible block of proliferation in E1A + cHa-ras transformants may be regarded as an example of activation of anticancer program like that of premature senescence in the tumor rodent cells.

Animals↗
PubMed2005

[Antiapoptotic oncogene bcl-2 induces a program of senescence in E1A + c-Ha-ras-transformants treated with adriamycin].

Introduction of bcl-2 gene in EIA + c-Ha-ras-transformed rat embryo fibroblasts, which are unable to be arrested after damaging influences and possess high proapoptotic sensitivity, results not only in suppression of cell death but also in re-establishment of cell cycle block following DNA damage and serum starvation. Flow cytometry showed that E1A + c-Ha-ras + bcl-2-transformants treated with DNA-intercalator adriamycin are capable of being arrested at G1/S boundary for a long time (for less than 5 days). According to the growth curve data, the number of Bcl-2-overexpressing cells remanins constant for a week of cultivation with adriamycin. Clonogenic efficacy of E1A + c-Ha-ras + bcl-2-cells is brought to no already in 16 h after adriamycin addition. Apoptotic death, revealed by oligonucleosomic fragmentation of DNA, as well as cell death, occurring due to mitotic catastrophe, after adriamycin treatment are almost absent in Bcl-2-overexpressing transformants, as compared with parental E1A + c-Ha-ras-transformants. Bcl-2 introduction in E1A + c-Ha-ras-transformants is accompanied by a rise of SA beta-Gal (Senescence Associated beta-Galactosidase) activity, which is commonly considered to be a marker of cell senescence. Adriamycin treatment of E1A + c-Ha-ras + bcl-2-transformants results in a much higher rise in SA beta-Gal activity, as compared with untreated cells. Co-immunoprecipitation experiments demonstrated the introduction of Bcl-2 to result in formation of Bcl-2 complexes with early region E1A oncoproducts, which are thought to be responsible for proapoptotic susceptibility of E1A-expressing transformants. The data obtained lead to suggestion that bcl-2 transfer to E1A + c-Ha-ras-transformants may induce a switch from the cell death program on the program of senescence after DNA damage, due, presumably, to Bcl-2 interaction with the apoptosis activator the viral oncoprotein E1A.

Adenovirus E1A Proteins↗
PubMed2000

[The MDR gene and cellular sensitivity to various effects].

mdr-Transfected K-562 cells revealed a relatively high resistance to cytotoxic monokines and ionizing radiation as compared to parental cells. Taken together with what is known about the resistance of mdr-expressing cells to multiple cytotoxic drugs, our results point to malignant cells having universal mechanisms of chemo-, bio- and radioresistance.

Cell Division↗
PubMed1999

[Effect of ionizing radiation on functional activity of macrophagesĭ].

It was shown that in vitro irradiation (8 Gy) of murine peritoneal macrophages suppressed their spontaneous cytotoxity and induced growth-stimulating activity. Exposure to 4 Gy induced mRNA proximal factors--TGF-beta and TNF-alpha and boosted growth-stimulating activity. These effects should be considered when evaluating efficacy of radiotherapy for tumors.

Animals↗
PubMed1997

[The effect of activated macrophage products on neurite growth in an organotypic culture of chick embryo sensory ganglia].

Murine peritoneal macrophages, activated by BCG vaccine, and human peripheral blood monocytes, activated by lipopolysaccharides, exerted neurite stimulating or neurite inhibiting effects in various periods of activation. The supernatants of these preparations were active in organotypic culture of chick embryo dorsal root ganglia. The inhibition of neurite growth on the 1st day of cultivation was followed by the neurite-stimulating effect. The fluctuation of neurite-inhibition and neurite-stimulation effect of macrophage supernatants suggest the availability of certain changes in cytokine composition in different periods of macrophage activation.

Animals↗
PubMed1996

[Synthesis and expression of transforming growth factor-beta in activated macrophages].

It has been established that once macrophages become activated, they pass through different stages of functional activity. Mouse macrophages activated by BCG "exerted" pronounced cytotoxic effects for 2-5 days to be followed later by growth-stimulating ones. However, in other experiments, the cytotoxic effect was either absent or occurred at later stages which was probably due to a certain functional state of macrophages before activation. The synthesis of TGF-beta increased 1-2 days after activation with BCG vaccine, lipopolysacharide and gamma radiation. An increase in mRNA TGF-beta i expression was observed only 5 days after activation of macrophages.

Animals↗
PubMed1992

Modulation of KB and A431 cell adhesion by epidermal growth inhibitory pentapeptide.

A pentapaptide, pyroGlu-Glu-Asp-Ser-GlyOH (EPP), isolated from mouse epidermis, inhibits mitoses and enhances differentiation in primary cultures and in transformed mouse epidermal cells in vitro (Elgjo et al. 1986 b). The present work demonstrates that EPP also modulates the adhesiveness of two human tumour cell lines (KB and A431) of epidermal origin to uncoated plastic and to plastic coated with fibrinogen or collagen type 1. The adhesion modulatory effect of EPP was observed over a broad range of concentrations (10(-12)-10(-6) M), and depended on the substrate the cells were growing on. Thus, when cells were seeded on plastic or collagen, the attachment to the substrate was suppressed at the highest concentrations of EPP, and stimulated at the lowest ones. The opposite concentration-response pattern was observed when fibrinogen was used as substrate.

Amino Acid Sequence↗