[Apoptosis and neutrophils on the regulation of proliferation and differentiation ex vifo of myeloid cells with Ph-chromosome].

Human myeloid cells with Ph chromosome (Ph+ cells) from chronic myeloid leukemia (CML) in the course of proliferation and differentiation ex vivo are regulated under alternation of cell proliferation and neutrophil maturation stages by consecutive blocking and inducing apoptosis with of neutrophils participation as well bcr/abl, bax and bcl2 genes expression. Apoptosis regulation of three main Ph+ cells types from CML patients depends on alternation sequences of proliferation (1) and maturation (2) cell stages and realized by two ways. The first one is performed by consecutive blocking and inducing apoptosis under 2/1/2 stage alternation.

Gene Expression upon Proliferation and Differentiation of Hematopoietic Cells with Ph Chromosome ex vivo.

The genesp53, mdm2, p21, c-myc,bcr/abl, bcr, bcl2, bax, and gapdh participate in the regulation of cell proliferation and differentiation, apoptosis and cell distribution for the cell cycle ex vivo in the Ph(+)cells of chronic myeloid leukemia containing the Ph chromosome andbcr/abloncogene. Expression of these genes correlates with regulation of cell proliferation and differentiation by alternating proliferation and maturation stages for three main Ph+cell types that occur under chronic myeloid leukemia. Thep53, p21, mdm2, and gapdh genes overexpress in active proliferating myeloid cells in the cell cycle S+ G2/M phases and when the phases are coincident with the proliferation stage.

Cell Regulation of Proliferation and Differentiation ex vivo for Cells Containing Ph Chromosome in Chronic Myeloid Leukemia.

Cell regulation of Ph(+)cell proliferation and differentiation has been studied ex vivo in various chronic myeloid leukemia (CML) patients. The regulation is provided by alternation of effective stages of proliferation and maturation with inhibition of Ph(+) cell proliferation by accumulating neutrophils under apoptosis blockage. The alternation of stages consists of switching stage 1 (effective proliferation) to stage 2 (effective maturation) and proceeds according to the 1/2 -1/2/1 or 2/1-2/1/2/1 schemes.

[Kinetics of proliferation, differentiation and transcription of genes regulating apoptosis in cultured human BCR/ABL+ Ph+-cells].

Ph+, bcr/abl+ cells arise due to t(9,22) chromosome translocation and Ph+ chromosome formation in hematopoietic stem cells. The cells show appreciable apoptosis suppression but retain their ability to differentiate and maturate. Ph chromosome, bcr/abl oncogene and Ph+, bcr/abl+ cells themselves are the hallmark of chronic myeloid leukemia.

[Parameters of binding and transport of oligodeoxynucleotide, which includes BCL2 mRNA translation start, to the K562 cells].

Interaction of oligodeoxynucleotides (ODN), 18-mer, which included sequence of BCL2 mRNA translation start, with K562 cells has been studied. The kinetic curves of interaction showed that oligonucleotide total binding with the cells at 37 degrees C and low oligonucleotide concentration (< or = 30 nM), as well as under lipofection, were composed of two processes: 18-mer surface binding with cell membranes and its non-proportional internalization into the cells. The last, in turn, consisted of three consequent steps.

Binding features of BCL2-targeted oligodeoxynucleotides with K562 cells.

Delivery of various oligodeoxynucleotides into cells is mediated by binding to certain surface proteins followed by receptor-mediated endocytosis. Moreover, oligonucleotides are able to provoke perturbation of cell surface proteins and growth factor receptors among them. Here we described binding sense BCL2 oligodeoxynucleotide targeted to translation start of BCL2 mRNA (ODN) with K562 cells.

Adenoviruses synergize with nuclear localization signals to enhance nuclear delivery and photodynamic action of internalizable conjugates containing chlorin e6.

Photosensitizers, molecules that produce active oxygen species upon activation by visible light, are currently being used in photodynamic therapy (PDT) to treat cancer and other conditions, where limitations include normal cells and tissue damage and associated side effects, and the fact that cytotoxic effects are largely restricted to the plasma and other peripheral membranes. In this study, we used insulin-containing conjugates to which variants of the simian-virus-SV40 large-tumor antigen (T-ag) nuclear localization signal (NLS) were linked in order to target the photosensitizer chlorin e6 to the nucleus. NLSs were included either as peptides coupled co-valently to the carrier bovine serum albumin, or within the coding sequence of beta-galactosidase fusion proteins.

Nuclear targeting of chlorin e6 enhances its photosensitizing activity.

Although photosensitizers, molecules that produce active oxygen species upon activation by visible light, are being extensively used in photodynamic therapy to treat cancer and other clinical conditions, problems include normal cell and tissue damage and associated side effects, which are attributable in part to the fact that cytotoxic effects are largely restricted to the plasma membrane. We have previously shown that the photosensitizer chlorin e6 has significantly higher photosensitizing activity when present in conjugates containing specific ligands and thus able to be internalized by receptor-expressing cells. In this study we use insulin-containing conjugates to which variants of the simian virus SV40 large tumor antigen nuclear localization signal (NLS) were linked to target chlorin e6 to the nucleus, a hypersensitive site for active oxygen species-induced damage.

Insulin-mediated intracellular targeting enhances the photodynamic activity of chlorin e6.

Photodynamic therapy has been applied quite extensively over the last few years, whereby the activation of photosensitizers by light causes the production of reactive oxygen species such as singlet oxygen, which is cytotoxic. The goal of this study was the enhancement of the photodynamic activity of photosensitizers through their delivery to specific, sensitive intracellular compartments of target cells. We synthesized a BSA-insulin-chlorin e6 conjugate that bound specifically to the insulin receptors (EC50, 1 nM) of the human hepatoma cell line PLC/PRF/5 and could be internalized by receptor-mediated endocytosis.

The use of internalizable derivatives of chlorin E6 for increasing its photosensitizing activity.

Experiments with human hepatoma PLC/PRF/5 cells and human embryo skin fibroblasts involving the use of three different tests (colony formation, Trypan blue exclusion, labeled thymidine incorporation) have demonstrated a significantly higher photosensitizing activity of chlorin e6 conjugates with internalizable ligands as compared to that of chlorin e6 itself. Receptor-mediated internalization of chlorin e6 conjugates ensures a greater photosensitization of cells than binding of those conjugates to cell surface receptors. The suitability of such conjugates that permit the delivery of a photosensitizer to sensitive intracellular targets is discussed.

Internalizable insulin-BSA-chlorin E6 conjugate is a more effective photosensitizer than chlorin E6 alone.

Experiments with human hepatoma PLC/PRF/5 cells involving the use of two different tests (colony formation and Trypan blue exclusion) have demonstrated a significantly higher photosensitizing activity of chlorin e6 conjugates with bovine serum albumin (BSA) and internalizable ligand insulin as compared to that of chlorin e6 itself. Receptor-mediated internalization of insulin-BSA-chlorin e6 conjugates ensures greater photosensitization of cells than the binding of those conjugates to cell surface receptors. The suitability of such conjugates permitting the delivery of a photosensitizer to most sensitive cell structures is discussed.

[Photodynamic effects of a concanavalin A-chlorin e6 conjugate on human fibroblasts].

To minimize the side effect of porphyrin photosensitizers and to reduce their active concentration, chlorine e6 was conjugated with concanavalin A. Photodynamic action of chlorine e6 and concanavalin A-chlorine e6 conjugate has been studied in human skin embryonic fibroblasts. The conjugate appeared to be 5 times more effective as compared to chlorine e6 due to concanavalin A-chlorine e6 endocytosis into intracellular compartments.

[Dependence of the nature of the action of metabolic inhibitors on ribosomal RNA synthesis in Ehrlich ascites carcinoma cells on cell integrity].

Ribosomal RNA (rRNA) synthesis in the intact Ehrlich ascite carcinoma cells is selectively inhibited by papaverin (ED50 = 0.01 mM), 2,4-dinitrophenol (DPN; ED50 = 5 microM), and actinomycin D (ED50 = 0.1 microgram/ml).

[Effect of hydrophobic compounds on rRNA synthesis in intact cells and isolated nuclei].

Papaverine, cycloheximide, 2,4-dinitrophenol (DNP) and actinomycin D at low concentration have been shown to suppress selectively rRNA synthesis in Ehrlich ascite carcinoma cells. rRNA synthesis in isolated nuclei is not sensible to wide range of concentration of papaverine (0,005-0,1 mM), cycloheximide (0,5-100 micrograms/ml) and DNP (5-500 microM). Actinomycin D at low concentration does not act on the rRNA synthesis in vitro either.

[Inhibitor interaction in the suppression of ribosomal RNA synthesis in Ehrlich ascites carcinoma cells].

Kinetic analysis of inhibitory action of papaverine, 2,4-dinitrophenol (DNP) and actinomycin D on RNA synthesis in the intact Ehrlich ascites carcinoma cells has shown that the action of these agents is mediated by their effect on the same step of rRNA synthesis.

[Effect of 2,4-dinitrophenol on the synthesis of ribosomal RNA in the cells of Ehrlich ascitic carcinoma under anaerobic conditions].

It is shown that 2,4-DNP (20 mkM to 1 mM) selectively inhibited RNA synthesis in Ehrlich ascite carcinoma cells both in aerobic and in anaerobic conditions in equal extent. It is supposed that the inhibitory action of DNP is not associated with its influence on oxidative phosphorylation and intracellular ATP concentration, but may be accounted for cell reaction to non-specific actions.

[Effect of cycloheximide, 2,4-dinitrophenol and papaverine on ribosomal RNA synthesis in Ehrlich ascitic carcinoma cells].

The influence of 2,4-dinitrophenol (DNP), papaverine and cycloheximide on RNA synthesis in Ehrlich ascites tumour cells has been investigated. All above mentioned agents inhibit selectively synthesis of high-molecular rRNA precursor, when the cell population density is 3.10(7)--5.