Remodulating effect of doxorubicin on the state of iron-containing proteins, and redox characteristics of tumor with allowance for its sensitivity to cytostatic agents.

The study was aimed at determining the changes of metal-containing proteins in blood serum and tumor tissue of animals with parental and doxorubicin-resistant strains of Walker-256 carcinosarcoma before and after the cytostatic administration. It has been shown that upon doxorubicin action the levels of total iron and transferrin in the tissues from the both groups of animals decreased while that of ferritine simultaneously increased with more pronounced pattern in the group of animals with resistant tumor strain. It has been shown that upon the action of doxorubicin in tumor tissue of animals with different sensitivity to the cytostatic there could be observed oppositely directed changes in the redox state of these cells that in turn determined the content of " free iron" complexes, RO S generation and concentration of active forms of matrix metaloproteinase- 2 and matrix metaloproteinase-9, namely, the increase of these indexes in animals with parental strain and their decrease in animals with the resistant one. So, our study has demonstrated the remodulating effect of doxorubicin on the state of metal-containing proteins and redox characteristics of tumor dependent on its sensitivity to cytostatic, at the levels of the tumor and an organism. These data may serve as a criterion for the development of programs for the correction of malfunction of iron metabolism aimed at elevating tumor sensitivity to cytostatic agents.

[Lewis lung carcinoma variant with high sensitivity to antitumor antiangiogenic therapy reveals a high capacity to autophagy].

Comparative investigation of two variants of Lewis lung carcinoma cells (LLC and LLC/R9) growing under nutrient deficiency caused by long-term incubation without growth medium replacement was performed. It was established that LLC/R9 cells which in contrast to LLC cells had a high sensitivity to antitumor antiangiogenic therapy (AAT) revealed a high dependence of their survival from glucose level in growth medium as well as high capacity to autophagy under nutrient deficiency. Perhaps high autophagy activity in tumor cells may be considered as a marker of tumor AAT sensitivity.

Ultrastructural and some functional changes in tumor cells treated with stabilized iron oxide nanoparticles.

AIM: To study the ultrastructure and some functional indexes of tumor cells treated with stabilized iron nanoparticles in vitro. METHODS: 3-[4,5dimethylthiazol-2-1]-2,5-diphenyltetrazolium bromide (MTT)-test, electron microscopy, polarography with applying of closed Clark's electrode. RESULTS: It was shown that cultivation of cells with stabilized Fe(3)O(4) leads to intracellular accumulation of ferromagnetic nanoparticles. The most active ferromagnetic uptake by cells has been observed after 24 and 48 h of incubation. The presence of ferromagnetic in cells led to altered mitochondrial structure that caused the decrease of oxygen uptake rate in the cells of all studied lines. Ferromagnetic released from the majority of cells via exocytosis or clasmacytosis after a certain period of time. The number of dead cells or cells with severe damage was moderate, so cytotoxic action of stabilized iron oxide nanoparticles was minimal toward the studied cell lines. CONCLUSION: the presence of ferromagnetic nanoparticles in culture medium led to alterations in mitochondria ultrastructural organization and decrease of oxygen uptake by mitochondria in sensitive and anticancer-drugs resistant cells.

Molecular profile and cell cycle in MCF-7 cells resistant to cisplatin and doxorubicin.

AIM: To compare ultrastructure, phenotypic profile and cell cycle progression of MCF-7 human breast cancer cells and MCF7 sublines resistant to cisplatin (MCF-7/DDP) and doxorubicin (MCF-7/DOX). METHODS: MTT-test, immunocytochemistry, flow cytometry, electron microscopy. RESULTS: The development of drug resistance to cisplatin and doxorubicin in MCF-7 cells upon the culturing of the initial cells with the raising concentrations of cytostatics was accompanied by the increase in cells adhesion, the increasing differentiation grade and the loss of steroid hormone receptors. Besides, it was shown that antiapoptotic mechanisms (decrease of Bcl-2 expression) and intracellular glutathione detoxifying system are involved in the process of cisplatin resistance development in MCF-7 cells. At the same time, P-glycoprotein overexpression in cells resistant to doxorubicin suggests MDR-dependent mechanism. Both doxorubicin- and cisplatin-resistant cells are characterized by the changes in the expression of several cell cycle regulators -- Ki-67, cyclin D1, pRb and p21). CONCLUSION: The long-time culture of MCF-7 cells with cytostatic drugs results in the decreased cyclin D1, pRb, and Ki-67 expression and increased p21 expression with the increasing differentiation grade of the resistant cells. The underlying mechanisms of resistance to cisplatin and doxorubicin in MCF-7 cells may be different.

Modifying influence of prolonged action of interferon on phenotypic characteristics of human lung cancer cells in vitro.

AIM: To study modifying influence of interferon (IFN) on some phenotypic properties of human non-small-cell lung cancer cells (NSCLC) upon prolonged exposition of the cells with IFN. MATERIALS AND METHODS: A-549 cells were cultivated with IFN at increasing concentrations for a long period of time (up to 1 year). Cell morphology and ultrastructure were studied by light and electron microscopy. Expression of adhesion protein E-cadherin, and vimentin, cytosceleton protein associated with tumor cell migration and invasion, antigen of proliferating cells Ki-67, angiogenesis-stimulating protein VEGF were studied using the method of immunocytochemistry. Autonomity of the cell growth was studied with the use of colony formation in soft agar, platting efficiency assay, and growth in serum-free medium. RESULTS: It has been shown that prolonged action of IFN results in significant and irreversible inhibition of manifestation of malignant phenotype: decreased of proliferative potential and inhibited autonomy of the cells; in complicated cell ultrastructure; in decreased expression vimentin and in increased expression of E-cadherin. Also, an inhibiting influence of IFN on expression of EGF receptors and VEGF in tumor cells have been shown. CONCLUSIONS: The data are showing that prolonged exposition of NSCLC cells to IFN is accompanied by stable phenotypic alterations of the cells directed on significant loss of malignancy and their shift to more differentiated phenotype.

[Ultrastructural organization of carcinoma Lewis (3LL) cells during cisplatin resistance formation].

The electron-microscopic analysis of the morphological status of 3LL (Lewis) carcinoma tumour cells in the process of cisplatin resistant phenotype formation has been performed. It was shown that selection of tumour cells forming cell clones characterized by more complicated nuclear and cytoplasm organization took place. The tumour cells had the diffused nuclear chromatin; nuclear envelope had the numerous pores with expanded diaphragms. The prominent nucleoli consisted of the active centres surrounded by considerable areas of the condensed nucleolar chromatin. Cell cytoplasm contained the well-developed Goldgi complex and the numerous well-structured myelinoid formations in the form of dense-wrapped concentric membrane structures. The obtained data can morphologically confirm the hypothesis of Gately D.P. and Howel S.B., 1993, thain the process of resistant phenotype formation the tumour cells can create the cellular mechanisms to remove the drug from the cell and to correct the damages of the cellular nucleus and cytoplasm.

[A method for the chemical treatment of cells for the purpose of the subsequent study of the same cell culture preparation by light, scanning and transmission electron microscopy]. / Metod khimicheskoi obrabotki kletok s tsel'iu posledovatel'nogo izucheniia odnogo i togo zhe preparata kletochnoi kul'tury s pomoshch'iu svetovoi, rastrovoi i transmissionnoi élektronnoi mikroskopii.

Cells cultured on transparent conductive substrates (glass coated with indium oxide) were fixed with aldehyde and osmium tetroxide and then treated with tannic acid, uranyl acetate and lead citrate. The same cell culture preparation could be sequentially studied by light microscopy (in water immersed condition), SEM (after dehydration and critical point drying) and TEM (after embedding in an epoxy resin). This method ensures the preservation of intact cell morphology, cell surface topography and intracellular structures. The treatments used render the cells conductivity and permit to carry out successfully SEM of uncoated cells cultured on conductive substrates. This method also provides a higher contrast of TEM images.

[Ultrastructural anomalies of the desmosomal contacts in monolayer transformed cultures]. / Anomalii ul'trastruktury desmosomal'nykh kontaktov v monosloinykh transformirovannykh kul'turakh.

The ultrastructure of cell-cell desmosomal contacts and their cytoskeletal components in the cellular monolayer of transformed epithelial cultures is studied. It is suggested that asymmetry of the desmosomal contact formation, the formation of hemidesmosome-like structures on the lateral surface of one of the contacted cells and defects of cytoskeletal desmosomal components are related to transformational changes in the functionally different contacted cells.

[Ultrastructure of L-line lipoblast-like cells during cloning in a medium with a high serum concentration]. / Ul'trastruktura lipoblastopodobnykh kletok linii L v usloviiakh klonirovaniia v srede s vysokoi kontsentratsiei syvorotki.

The ultrastructure of lipoblast-like cells produced by clones of transformed culture of strain in the medium with an increased (60%) concentration of bovine serum was studied. The aim of using the stimulator rich in adipogenous factors was the elucidation of the origin of lipid accumulation in some of cell types during heterogeneous differentiation of clones. In these conditions non-differentiated lipoblasts assumed the fine structure of mature lipid cells. The statement of the marker significance of lipid accumulation in non-differentiated cells of the clones and the conversion of these cells under the influence of non-specific stimulator to the mature lipocytes confirms the data on conservation of over-all cytogenetic potentials and the capacity of their realization in the cells of transformed cultures. It is suggested that the increased concentration of bovine serum in the cultural medium not only stimulates differentiation (by any way determined cells), but is also capable of acting on the stem elements produced by the clone. In that case the influence of the stimulator on the trends of heterogeneous differentiation is not unlikely.

[Cellular ultrastructure of a cloned L-line culture]. / Ul'trastruktura kletok klonirovannoi kul'tury linii L.

A study of the fine structure of cells obtained from the transformed cloned culture of strain L, that have developed from a single cell, demonstrated several different cell types. The clones contained both non-differentiated and poorly-differentiated cells. The presence of morphotypical signs in the poorly-differentiated cells allowed to reveal some cell clone types and the direction of their specialization process. The study confirms the idea on the presence of the stem cell elements in the transformed cell culture of strain L causing the heterogenous way of cytodifferentiation and determining the long-term stability of cell polymorphism in this cell strain.

[L line cell differentiation. Histochemical and electron microscopic studies]. / [Differentsirovka kletok linii L. Gistokhimicheskoe iélektronno-mikroskopicheskoe issledovaniia.

In a medium supplemented with 60 per cent large cattle serum, part of the cell population of L-transformed culture was seen to be differentiated into mature lipocytes. The formation of structures similar to normal fat tissue took place in the same conditions, provided a reduced quantity of the seeded cells was used. The cell differentiation was accompanied with a decrease in acid phosphatase and non-specific esterase activities. The ultrastructural study has demonstrated a suitable preservation of cytoplasmic structures and a domination of the rough cytoplasmic reticulum compared to the control cell cultures where free ribosomes and polysomes predominated.

[Effect of chemical carcinogens on the ultrastructure of cultured differentiating myogenic cells]. / Deistvie khimicheskikh kantserogennykh veshchestv na ul'trastrukturu differentsiruiushchikhsia miogennykh kletok v kul'ture.

The electron microscope studies have been carried out on primary monolayer tissue culture obtained from body tissues of rat and C3H mouse embryos. The cells of tissue culture were mainly myoblasts and fibroblast-like cells. The cultures were treated with two different carcinogenic substances--benz(a)-pyrene (BP) and methylnitrosonitroguanidine (MNNG). The changes were uniform and showed some alterations in formation of cell complexes, the inhibition of development and maturing of muscle elements, and distrophy of cytoplasmic organelles. The revealed distinction in morphological reaction of myogenic cells to the effect of BP and MNNG were wave-like myofibrillar structures in MNNG-treated cultures.