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T P Stromskaia

Publications and source records attributed to T P Stromskaia.

13 recordsLinked to original sources
PubMed2001

[Functional activity and expression of P-glycoprotein in chronic myeloid leukemia].

AIM: To evaluate the prognostic significance of P-glycoprotein (Pgp) in chronic myeloid leukemia (CML). MATERIALS AND METHODS: Functional activity (rhodamine 123 test) and expression of Pgp (binding of UIC2 monoclonal antibodies by cells) were evaluated by flow cytofluorometry. A total of 141 samples of peripheral blood from 121 patients with various stages of CML were examined. RESULTS: The number of patients whose cells express functionally active Pgp increases during the blast crisis (BC) in comparison with the chronic phase (CP). Repeated testing of patients with BC and CP showed that Pgp-expressing cells can disappear from the peripheral blood of patients despite the treatment by Pgp preparations and substrates. However the number of cases with expression and functional activity of Pgp increases in the course of BC. Several patients in whom functionally active Pgp was not detected during diagnosis of BC had longer BC phase than patients with the active protein. CONCLUSION: These data suggest that active Pgp contributes to CML BC (presumably to patient's response to therapy) but this contribution is not decisive.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1990

[The cells of murine sarcoma PC-103 induced by a polymeric plate secret transforming growth factor alpha].

It was shown previously that cells of sarcoma PS-103 induced in mouse by subcutaneous transplantation of plastic film produce growth-stimulating activity. In this communication clone 3 sb, isolated from sarcoma PS-103, was studied. Growth factor produced by the cells of this clone stimulated proliferation of quasi-normal (3T3, NRK) cells and transformed cells both in monolayer and in semi-solid medium. It was shown by gel filtration chromatography that the main growth-stimulating activity migrated with the protein fraction m.m. 10-15 kDa. The addition of this growth factor to the culture medium significantly (90%) inhibited 125I-EGF (epidermal growth factor) binding by A-431 cells. These data suggest that the growth factor produced by the studied tumor cells is transforming growth factor alpha.

Animals↗
PubMed1990

[Multiple drug resistance and differentiation in the population of transformed dog kidney cells MDCK].

Sublines of the canine kidney epithelium cells (MDCK) resistant to various colchicine doses (0.3-5.0 mcg.ml-1) were obtained by multistep selection. The new lines were shown to possess multidrug-resistance (MDR) by means of Rhodamine 123 staining. The initial steps of resistance (2 mcg.ml-1, 300-fold increase in resistance) are evidently due to enhancement of mdr gene transcription. Approximately 4-fold gene amplification was revealed in the cells resistant to 3 mcg.ml-1 of colchicine. All the drug-resistant lines tested were found to be more prone to differentiation than the wild type cells (both spontaneous and induced by several drugs such as DMSO, cAMP and others). The data suggest that the selection for overexpression of mdr gene results in selection of variants that are more capable of differentiation than the rest of the population.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1986

[Clonal structure of tumors: difference between clones based on the ability to secrete growth-regulating factors and to react to them].

Conditioned medium isolated from different clones of tumour cell culture PS-103 (sarcoma induced in CBA mouse by plastic film implantation) varied in the ability to stimulate cell proliferation in semi-solid medium. The clones differed also in their response to the medium conditioned by culture PS-103: some clones responded by increased proliferation in semi-solid medium, some were inhibited and some failed to respond.

Animals↗
PubMed1984

[Relation between the attachment of cells to a substrate and their proliferative characteristics].

17 cloned cell lines of transformed mouse fibroblasts were used for the evaluation of a correlation between three traits of malignancy: cloning efficiency in semisolid medium (CE); cell dose inducing tumours in 50% of inoculated animals (TD50); degree of cell attachment to a substrate (RT50--rounding time for 50% of the cells under moderate cooling, 18 degrees C). It is shown that an increase in RT50 (better attachment of the cells to the substrate) is accompanied by a decrease in CE and an increase in TD50 (coefficients of rank correlation p = -0.76 and p = 0.58, respectively). A negative correlation between CE and TD50 was also revealed (p = -0.68). A certain increase in the percentage of cells containing actin filament bundles was found in cell clones better attached to the substrate. Mechanisms of disturbances in proliferation and attachment of malignant cells are discussed.

Animals↗
PubMed1982

[Effect of ethylmethane sulfonate on the expression of one of the traits of malignancy by cultured mouse cells].

The influence of ethyl methane sulfonate (methane sulfonic acid ethyl esther, EMS) on anchorage independence of tumor cells was studied. Mouse near-diploid spontaneously transformed clonal fibroblasts (CAK-25Agr were used. They were characterized by a stable low cloning efficiency in 1,2% methyl cellulose ((3-5) . 10(-5) per cell seeded into a semi-solid medium). EMS enhanced the quantity of CAK-25Agr colonies grown in methyl cellulose. However, this enhancement was only obtained when correction on the cloning efficiency of the cells in a liquid medium was introduced. Subclones of CAK-25Agr isolated from methyl cellulose were studied for their ability to form colonies in the semi-solid medium. The number of subclones with elevated anchorage independence in cultures treated by a mutagen and in untreated cultures did not differ.

Animals↗
PubMed1982

[clonal analysis of the independence of tumor cell multiplication from the substrate].

The clone of near-diploid mouse transformed CAK-25AGr cells is characterized by the stable cloning efficiency in a semi-solid medium (about 10(-5) per cell plated in methylcellulose). It was shown that colonies in the semi-solid medium were formed by rare single cells and did not arise as a result of slow multiplication of all cells in the population. These cells are not genetical variants different from other cells in the culture. This is assumed on the basis of following data. First, the majority of the subclones arising in methylcellulose (9 of 12) retained parental cloning efficiency in the semi-solid medium. Second, all 6 subclones picked from the solid substratum had the ability to form colonies in methylcellulose with the frequency not lower than that of the parental clone. Apparently, the proliferation in methylcellulose of the transformed cells studied is a stochastic process. Each cell in the culture has the ability to initiate a colony in the semi-solid medium with the certain probability. This probability is a heritable characteristic of the cloned cell line. It is possible that this characteristic reflects the norm of reaction of the cells to some environmental factors.

Animals↗
PubMed1980

[Murine near-diploid cell clones: a model for the genetic analysis of signs of transformation].

Several near-diploid clones were obtained from the established mouse cell line, CAK-7. These clones proved to be highly oncogenic in syngeneic irradiated mice (TD50 = 1 x 10(2)--2 x 10(3). They differed in plating efficiency in semi-solid medium (from 5 x 10(-3) to 22 x 10(-5)). There was no correlation between tumorigenicity of the cells and their plating efficiency in methylcellulose. The differences between clones able to form anchorage-independent clonies would permit their use for the genetic analysis of this kind of malignancy.

Animals↗
PubMed1979

[Cell rounding in variant sublines of the L line caused by a moderate decrease in temperature].

Several novel variants of mouse transformed L cells are described. A distinctive trait of these variants, isolated by different methods, is a rounding of the majority of cells under the influence of the moderate cooling (at 18 degrees C for 30-60 min). In the serum-free medium, no rounding occurs. The rounding is presumably an active contraction, because it is inhibited by cytochalasin B. The comparison of the phenotype of wild-type and variant cells has shown that the exposure of cultures at 18 degrees leads to a disturbance of cell adhesion to the substratum in both the cell lines. The intensive rounding of variant cells at 18 degrees is due to some defect in their attachment to the substratum, which can be revealed not only at 18 degrees, but also at 37 degrees. By the selection procedure described in this paper, a large group of cell variants defective in adhesion to the substratum may be isolated.

Animals↗