Amifostine protects normal cells from DNA damage induction by ionizing radiation or chemotherapeutics, whereas cancer cells typically remain uninfluenced. While confirming this phenomenon, we have revealed by comet assay and currently the most sensitive method of DNA double strand break (DSB) quantification (based on γH2AX/53BP1 high-resolution immunofluorescence microscopy) that amifostine treatment supports DSB repair in γ-irradiated normal NHDF fibroblasts but alters it in MCF7 carcinoma cells. These effects follow from the significantly lower activity of alkaline phosphatase measured in MCF7 cells and their supernatants as compared with NHDF fibroblasts. Liquid chromatography-mass spectrometry confirmed that the amifostine conversion to WR-1065 was significantly more intensive in normal NHDF cells than in tumor MCF cells. In conclusion, due to common differences between normal and cancer cells in their abilities to convert amifostine to its active metabolite WR-1065, amifostine may not only protect in multiple ways normal cells from radiation-induced DNA damage but also make cancer cells suffer from DSB repair alteration.

• MeSH
• alkalická fosfatasa genetika   metabolismus   MeSH
• amifostin farmakokinetika   farmakologie   MeSH
• dvouřetězcové zlomy DNA účinky léků   MeSH
• fibroblasty účinky léků   účinky záření   MeSH
• fluorescenční mikroskopie metody   MeSH
• histony genetika   metabolismus   MeSH
• intracelulární signální peptidy a proteiny genetika   metabolismus   MeSH
• kometový test MeSH
• lidé MeSH
• merkaptoethylaminy farmakokinetika   MeSH
• MFC-7 buňky účinky léků   účinky záření   MeSH
• oprava DNA účinky léků   MeSH
• poškození DNA účinky léků   MeSH
• radioprotektivní látky farmakologie   MeSH
• záření gama MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Influence of the regulatory system mediated by adenosine A(3) receptors on the functioning of erythropoiesis and thrombopoiesis was studied by means of evaluation of the numbers and attributes of peripheral blood erythrocytes and platelets, as well as of erythroid bone marrow progenitor cells in adenosine A(3) receptor knock-out (Adora3(tm1Jbsn)/Adora3(tm1Jbsn), A(3)AR((-/-))) mice and their wild-type C57BL/6 counterparts, both males and females. Minor but statistically significant disturbances in the properties of erythrocytes, namely in the parameters of mean erythrocyte volume and mean erythrocyte hemoglobin were observed in A(3)AR((-/-)) mice. In addition, adenosine A(3) receptor knock-out mice were found to exhibit an expressive, statistically significant decrease of their blood platelet count, amounting to 17 % and 21 % in males and females, respectively. This decrease in platelet levels was accompanied by a significant 17 % decline in the plateletcrit in both sexes. The obtained data can help to define therapeutic applications based on the principle of adenosine receptor signaling.

• MeSH
• erytrocyty cytologie   fyziologie   MeSH
• erytropoéza fyziologie   MeSH
• mezenchymální kmenové buňky cytologie   fyziologie   MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši MeSH
• receptor adenosinový A3 genetika   metabolismus   MeSH
• signální transdukce fyziologie   MeSH
• trombocyty cytologie   fyziologie   MeSH
• trombopoéza fyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The presented review summarizes experimental data obtained with a mouse model when investigating the relationship between inhibition of prostaglandin production and hematopoiesis. While prostaglandin E₂ acts in a negative feedback control of myelopoiesis, inhibition of cyclooxygenases, responsible for its production, shifts the feedback to positive control. Based on these relationships, agents inhibiting cyclo-oxygenases, known as non-steroidal anti-inflammatory drugs (NSAIDs), can activate hematopoiesis and be protective or curative under myelosuppressive states. The effectiveness of therapeutic use of NSAIDs in these situations is expressive especially under the selective inhibition of cyclooxygenase-2 (COX-2), when undesirable side effects of cyclooxygenase-1 inhibition, like gastrointestinal damage, are absent. The effects of the clinically approved selective COX-2 inhibitor, meloxicam, were investigated and demonstrated significant hematopoiesis-stimulating and survival-enhancing actions of this drug in sublethally or lethally γ-irradiated mice. These effects were connected with the ability of meloxicam to increase serum levels of the granulocyte colony-stimulating factor. It can be inferred from these findings that selective COX-2 inhibitors might find their use in the treatment of myelosuppressions of various etiologies.

• MeSH
• antiflogistika nesteroidní terapeutické užití   MeSH
• cyklooxygenasa 2 metabolismus   MeSH
• dinoproston metabolismus   MeSH
• faktor stimulující kolonie granulocytů biosyntéza   krev   MeSH
• hematopoéza účinky léků   účinky záření   MeSH
• inhibitory cyklooxygenasy 2 terapeutické užití   MeSH
• lidé MeSH
• myelopoéza účinky léků   účinky záření   MeSH
• myši MeSH
• thiaziny terapeutické užití   MeSH
• thiazoly terapeutické užití   MeSH
• záření gama MeSH
• zpětná vazba fyziologická účinky léků   účinky záření   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

The BRCA1 gene codes for a protein involved in the DNA double strand break (DDSB) repair. Alongside the dominant full-length splicing form of BRCA1, numerous endogenously expressed alternative splicing variants of unknown significance have been described in various tissues. Some of them retain the original BRCA1 reading frame but lack several critical BRCA1 structural domains, suggesting an altered function of the resulting protein in the BRCA1-regulated processes. To characterize the effect of the BRCA1Δ14-15 splicing variant (with an in-frame deletion affecting the regulatory serine-containing domain) on the DDSB repair, we constructed the MCF-7 clones stably expressing the analyzed variant with/without a shRNA-mediated downregulation of the endogenous full-length wild-type BRCA1 expression. Our results show that the expression of the BRCA1Δ14-15 variant delays the γ-radiation-induced DDSB repair, alters the kinetics of irradiation-induced foci formation/decomposition and reduces the non-homologous end-joining capacity in MCF-7 cells. Therefore, the BRCA1Δ14-15 is not able to functionally replace the full-length wt BRCA1 in the DDSB repair. Our findings indicate that the endogenously expressed BRCA1 alternative splicing variants may negatively influence genome stability and support the growing evidence of the pathological potential of the sequence variants generated by an altered or misregulated alternative splicing in the process of mammary malignant transformation.

• MeSH
• buněčné jádro metabolismus   účinky záření   MeSH
• čtecí rámce MeSH
• dvouřetězcové zlomy DNA MeSH
• exprese genu MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• nádorové buněčné linie MeSH
• nádory prsu MeSH
• oprava DNA spojením konců MeSH
• protein - isoformy genetika   metabolismus   MeSH
• protein BRCA1 genetika   metabolismus   MeSH
• sekvence aminokyselin MeSH
• sekvence nukleotidů MeSH
• sekvenční delece MeSH
• terciární struktura proteinů MeSH
• záření gama MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Mouse hematopoiesis, suppressed by a sublethal dose of ionizing radiation, was the target for combined therapy with a cyclooxygenase-2 (COX-2) inhibitor meloxicam and an adenosine A₃ receptor agonist IB-MECA. The drugs were administered in an early postirradiation treatment regimen: meloxicam was given in a single dose 1hour after irradiation, IB-MECA in two doses 24 and 48hours after irradiation. Treatment-induced changes in several compartments of hematopoietic progenitor and precursor cells of the bone marrow were evaluated on day 3 after irradiation. Values of hematopoietic progenitor cells for granulocytes/macrophages and erythrocytes (GM-CFC and BFU-E, respectively), as well as those of proliferative granulocytic cells were found to be significantly higher in the mice treated with the drug combination in comparison to irradiated controls and attained the highest increase factors of 1.6, 1.6, and 2.6, respectively. The study emphasizes the significance of the combined treatment of suppressed hematopoiesis with more agents. Mechanisms of the action of the individual compounds of the studied drug combination and of their joint operation are discussed.

• MeSH
• adenosin aplikace a dávkování   analogy a deriváty   terapeutické užití   MeSH
• agonisté adenosinového receptoru A3 aplikace a dávkování   terapeutické užití   MeSH
• celotělové ozáření MeSH
• erytroidní prekurzorové buňky účinky léků   účinky záření   MeSH
• experimentální radiační poranění krev   farmakoterapie   patologie   MeSH
• faktor stimulující kolonie granulocytů krev   MeSH
• hematinika aplikace a dávkování   terapeutické užití   MeSH
• hematopoetické kmenové buňky účinky léků   účinky záření   MeSH
• hematopoéza účinky léků   účinky záření   MeSH
• inhibitory cyklooxygenasy 2 aplikace a dávkování   terapeutické užití   MeSH
• kombinovaná farmakoterapie MeSH
• křížení genetické MeSH
• myši inbrední CBA MeSH
• myši MeSH
• počet buněk MeSH
• prekurzorové buňky granulocytů účinky léků   účinky záření   MeSH
• thiaziny aplikace a dávkování   terapeutické užití   MeSH
• thiazoly aplikace a dávkování   terapeutické užití   MeSH
• záření gama škodlivé účinky   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The review summarizes data evaluating the role of adenosine receptor signaling in murine hematopoietic functions. The studies carried out utilized either non-selective activation of adenosine receptors induced by elevation of extracellular adenosine or by administration of synthetic adenosine analogs having various proportions of selectivity for a particular receptor. Numerous studies have described stimulatory effects of non-selective activation of adenosine receptors, manifested as enhancement of proliferation of cells at various levels of the hematopoietic hierarchy. Subsequent experimental approaches, considering the hematopoiesis-modulating action of adenosine receptor agonists with a high level of selectivity to individual adenosine receptor subtypes, have revealed differential effects of various adenosine analogs. Whereas selective activation of A₁ receptors has resulted in suppression of proliferation of hematopoietic progenitor and precursor cells, that of A₃ receptors has led to stimulated cell proliferation in these cell compartments. Thus, A₁ and A₃ receptors have been found to play a homeostatic role in suppressed and regenerating hematopoiesis. Selective activation of adenosine A₃ receptors has been found to act curatively under conditions of drug- and radiation-induced myelosuppression. The findings in these and further research areas will be summarized and mechanisms of hematopoiesis-modulating action of adenosine receptor agonists will be discussed.

• MeSH
• hematopoéza účinky léků   MeSH
• lidé MeSH
• purinergní receptory P1 účinky léků   MeSH
• signální transdukce MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

In this study we examined differences in selected indices of granulopoiesis in outbred, F(1) hybrid and inbred mouse strains. Specifically, serum granulocyte colony-stimulating factor (G-CSF) levels, numbers of marrow granulocyte-macrophage progenitor cells and morphologically recognizable proliferative marrow granulocytic precursor cells were evaluated. These parameters were determined in untreated controls, and in mice exposed either to a non-specific stimulus (injection of saline) or to a granulopoiesis-enhancing stimulus (administration of a cyclooxygenase-2 inhibitor, meloxicam). Lower levels of G-CSF were detectable in the outbred ICR mice, which also demonstrated an enhanced response to both types of the stimuli. Considering the fact that outbred mice are closer to natural mammalian populations, including human ones, the possibility of using outbred mice, instead of the often used inbred strains, for experiments evaluating the effects of pharmacological interventions on hematopoiesis should be investigated.

• MeSH
• buňky kostní dřeně cytologie   účinky léků   MeSH
• chlorid sodný aplikace a dávkování   farmakologie   MeSH
• faktor stimulující granulocyto-makrofágové kolonie krev   MeSH
• faktor stimulující kolonie granulocytů krev   MeSH
• granulocyty cytologie   účinky léků   MeSH
• hybridizace genetická genetika   MeSH
• inbrední kmeny myší MeSH
• inbreeding MeSH
• inhibitory cyklooxygenasy farmakologie   MeSH
• injekce intraperitoneální MeSH
• lidé MeSH
• myelopoéza účinky léků   fyziologie   MeSH
• myši MeSH
• progenitory granulocytů a makrofágů MeSH
• proliferace buněk účinky léků   MeSH
• thiaziny farmakologie   MeSH
• thiazoly farmakologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Our previous studies have shown that the combined administration of drugs elevating extracellular adenosine, i.e. dipyridamole (DP) and adenosine monophosphate (AMP), enhances murine hematopoiesis and potentiates the action of granulocyte colony-stimulating factor (G-CSF). In this study, colony-stimulating activity (CSA) of blood serum of mice treated with DP+AMP, G-CSF or all these drugs in combination, i.e. the ability of the sera to stimulate the growth of GM-CFC colonies, was assayed in vitro. Furthermore, the concentration of GM-CSF and IL-6 in the sera was determined. Administration of DP+AMP was found to enhance significantly serum CSA at all time intervals of serum sampling including 24 h after the last injection of the tested drugs. Additive effects of DP+AMP and G-CSF on serum CSA were noted at early intervals after administration of the drugs. Furthermore, IL-6 levels were significantly elevated in the sera of mice which were administered DP+AMP either alone or in combination with G-CSF. Our results show that the effects of DP+AMP are indirect, mediated through the induction of some cytokine(s) and/or growth factor(s) and that extracellular adenosine can act in cooperation with G-CSF. These findings contribute to the further elucidation of the role of adenosine in hematopoiesis.

• MeSH
• adenosin analogy a deriváty   imunologie   MeSH
• adenosinmonofosfát aplikace a dávkování   krev   MeSH
• dipyridamol aplikace a dávkování   krev   MeSH
• ELISA normy   využití   MeSH
• extracelulární prostor genetika   imunologie   účinky léků   MeSH
• faktor stimulující kolonie granulocytů izolace a purifikace   účinky léků   MeSH
• financování organizované využití   MeSH
• myši inbrední CBA krev   MeSH
• myši inbrední ICR krev   MeSH

IMUNOR, a low-molecular weight (< 12 kD) ultrafiltered pig leukocyte extract, has been previously found to have significant stimulatory effects on murine hematopoiesis supressed by ionizing radiation or cytotoxic drugs. This communication shows data on the mechanisms of these effects. Using ELISA assay, significantly increased levels of granulocyte colony-stimulating factor (G-CSF) and interleukin-6 (IL-6) were observed. On the contrary, no detectable levels of granulocyte-macrophage colony-stimulating factor (GM-CFC) and interleukin-3 (IL-3) have been found in blood serum of IMUNOR-treated mice. Incubation of the serum from IMUNOR-treated mice with antibodies against G-CSF caused abrogation of the ability of the sera to stimulate in vitro growth of colonies originating from granulocyte-macrophage progenitor cells (GM-CFC). In contrast, incubation of the serum with antibodies against IL-6 did not change its colony-stimulating activity. It may be inferred from these findings that G-CSF is probably the main cytokine responsible for the granulopoiesis-stimulating effects of IMUNOR. When the serum from IMUNOR-treated mice with G-CSF inactivated by anti-G-CSF antibodies (but with elevated IL-6) was added to cultures of bone marrow cells together with a suboptimum concentration of IL-3, a significant increase in the numbers of GM-CFC colonies was found. Moreover, conjoint inactivation of G-CSF and IL-6 significantly decreased the numbers of GM-CFC colonies in comparison with those observed when only G-CSF was inactivated. This observation strongly suggests that though IMUNOR-induced IL-6 is not able to induce the growth of GM-CFC colonies alone, it is able to potentiate the hematopoiesis-stimulating effect of IL-3. These findings represent a new knowledge concerning the hematopoiesis-stimulating action of IMUNOR, a promising immunomodulatory agent.

• MeSH
• antisérum farmakologie   MeSH
• chemická stimulace MeSH
• ELISA MeSH
• faktor stimulující kolonie granulocytů antagonisté a inhibitory   fyziologie   MeSH
• financování organizované MeSH
• granulocyty fyziologie   MeSH
• hematopoéza účinky léků   MeSH
• interleukin-3 antagonisté a inhibitory   MeSH
• interleukin-6 antagonisté a inhibitory   fyziologie   MeSH
• kostní dřeň metabolismus   účinky léků   MeSH
• leukocyty fyziologie   MeSH
• monoklonální protilátky farmakologie   MeSH
• myši MeSH
• prasata MeSH
• protilátky blokující farmakologie   MeSH
• tkáňové extrakty farmakologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH

Adenosine has been observed to suppress the growth of MOLT-4 human leukemia cells in vitro. Changes in the cell cycle, especially increased percentage of cells in S phase, prolonged generation time, and induction of apoptosis at higher adenosine concentrations have been found to be responsible for the growth suppression. Dipyridamole, a drug inhibiting the cellular uptake of adenosine, reversed partially but significantly the adenosine-induced growth suppression. It follows from these results that the action of adenosine on the MOLT-4 cells comprises its cellular uptake and intracellular operation. These findings present new data on anticancer efficacy of adenosine.

• MeSH
• adenosin antagonisté a inhibitory   farmakologie   metabolismus   MeSH
• antitumorózní látky antagonisté a inhibitory   farmakologie   metabolismus   MeSH
• apoptóza MeSH
• biologický transport účinky léků   MeSH
• dipyridamol farmakologie   MeSH
• financování organizované MeSH
• inhibitory fosfodiesteras farmakologie   MeSH
• leukemie T-buněčná patologie   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• proliferace buněk účinky léků   MeSH
• Check Tag
• lidé MeSH