- Klíčová slova
- biodozimetrie,
- MeSH
- elektrochemické techniky metody MeSH
- hematopoéza účinky záření MeSH
- histony analýza účinky záření MeSH
- imunofenotypizace metody MeSH
- ionizující záření * MeSH
- lidé MeSH
- mikrojaderné testy metody MeSH
- nukleové kyseliny analýza MeSH
- oxidační stres účinky záření MeSH
- poškození DNA * účinky záření MeSH
- průtoková cytometrie metody MeSH
- radiační expozice * analýza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- srovnávací studie MeSH
We evaluated the impact of ataxia-telangiectasia mutated kinase inhibitor KU55933, DNA-dependent protein kinase inhibitor NU7441 and ataxia telangiectasia and rad3-related kinase inhibitor VE821 in human peripheral lymphocytes in vitro. The lymphocytes were divided into 5 groups: non-irradiated control, irradiated group (2 Gy) and 3 groups pretreated with inhibitors 30 min before irradiation. We used flow cytometry to evaluate phosphorylated H2AX (γ-H2AX) and cytotoxicity (Apoptest). Micronucleus assay was used to assess genotoxicity. After irradiation, γ-H2AX, incidence of micronuclei (MN), nucleoplasmatic bridges (NPBs) and nuclear buds in binuclear cells, MN in mononuclear cells and apoptosis were increased. KU55933 decreased γ-H2AX and inhibited ionizing radiation-induced cytotoxicity. NU7441 showed no effect on γ-H2AX but it significantly increased MN and NPBs in binuclear cells and apoptosis. VE821 decreased γ-H2AX, whereas genotoxicity and cytotoxicity were not affected. In conclusion, KU55933 protected lymphocytes, which might be employed to preserve the immune system during anticancer therapy. NU7441 radiosensitized lymphocytes, thus, undesirable side effects toward immune system could be expected. VE821 showed decrease of γ-H2AX with no radiosensitizing effects in our model likely due to p53 positive status, which underlies the concept of its application in p53 negative environment.
- Klíčová slova
- Účinky ionizujícího záření způsobené inhibitory ATM (KU55933), DNA-PK (NU7441) a ATR (VE821) na lymfocyty periferní krve,
- MeSH
- ATM protein účinky záření MeSH
- biomedicínský výzkum MeSH
- financování organizované MeSH
- fosfatidylinositol-3-kinasy antagonisté a inhibitory účinky záření MeSH
- fosforylace imunologie účinky záření MeSH
- histony chemie účinky záření MeSH
- ionizující záření * MeSH
- krevní a imunitní systémy cytologie imunologie účinky záření MeSH
- lidé MeSH
- lymfocyty * cytologie imunologie účinky záření MeSH
- statistika jako téma MeSH
- techniky in vitro MeSH
- Check Tag
- lidé MeSH
DNA repair events have functional significance especially for genome stability. Although the DNA damage response within the whole genome has been extensively studied, the region-specific characteristics of nuclear sub-compartments such as the nucleolus or fragile sites have not been fully elucidated. Here, we show that the heterochromatin protein HP1 and PML protein recognize spontaneously occurring 53BP1- or γ-H2AX-positive DNA lesions throughout the genome. Moreover, 53BP1 nuclear bodies, which co-localize with PML bodies, also occur within the nucleoli compartments. Irradiation of the human osteosarcoma cell line U2OS with γ-rays increases the degree of co-localization between 53BP1 and PML bodies throughout the genome; however, the 53BP1 protein is less abundant in chromatin of ribosomal genes and fragile sites (FRA3B and FRA16D) in γ-irradiated cells. Most epigenomic marks on ribosomal genes and fragile sites are relatively stable in both non-irradiated and γ-irradiated cells. However, H3K4me2, H3K9me3, H3K27me3 and H3K79me1 were significantly changed in promoter and coding regions of ribosomal genes after exposure of cells to γ-rays. In fragile sites, γ-irradiation induces a decrease in H3K4me3, changes the levels of HP1β, and modifies the levels of H3K9 acetylation, while the level of H3K9me3 was relatively stable. In these studies, we confirm a specific DNA-damage response that differs between the ribosomal genes and fragile sites, which indicates the region-specificity of DNA repair.
- MeSH
- chromatin genetika MeSH
- chromozomální proteiny, nehistonové metabolismus účinky záření MeSH
- DNA vazebné proteiny účinky záření MeSH
- fibroblasty účinky záření MeSH
- fragilní místa na chromozomu genetika MeSH
- histony účinky záření MeSH
- jaderné proteiny metabolismus účinky záření MeSH
- lidé MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nádorové supresorové proteiny metabolismus účinky záření MeSH
- nestabilita genomu MeSH
- oprava DNA genetika MeSH
- osteosarkom MeSH
- poškození DNA účinky záření MeSH
- ribozomy genetika MeSH
- transkripční faktory metabolismus účinky záření MeSH
- záření gama MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Solar ultraviolet (UV) radiation is an important risk factor in skin carcinogenesis. This has been attributed mainly to the UVB waveband because the high-energetic photons are capable of interacting with DNA and inducing DNA damage. Recently, UVA light has also gained increasing interest in relation to DNA alteration. Although UVA photons are less energetic than UVB, they comprise a major fraction of sunlight UV radiation and penetrate deep into the skin. The study was carried out to compare the acute effects of UVA and UVB light on SKH-1 mice in relation to DNA damage and associated parameters. Mice were exposed to UVA (10 and 20 J/cm(2)) or UVB (200 and 800 mJ/cm(2)) radiation. The number of DNA single-strand breaks (SSB) in lymphocytes, amount of phosphorylated histone H2AX (gamma-H2AX) and apoptosis or DNA fragmentation (TUNEL-positive cells) in skin sections and level of gamma-H2AX, activated caspase-3 and phosphorylated p53 in skin were evaluated after 4 and 24 h. SSB analyzed by alkaline comet assay were found to be 4 and 24 h following UVB and UVA treatment, respectively. TUNEL and gamma-H2AX-positive cell were observed only in UVB exposed animals at both time intervals. The level of activated caspase-3 and phospho-p53 was increased 24 h after UVA and UVB radiation and was more apparent in UVB treated mice. The results indicate that the mechanism of DNA damage caused by acute UVA exposure includes formation of SSB (oxidative damage), but not double-strand breaks.
- MeSH
- apoptóza účinky záření MeSH
- DNA účinky záření MeSH
- fragmentace DNA MeSH
- histony účinky záření MeSH
- jednořetězcové zlomy DNA MeSH
- kaspasa 3 účinky záření MeSH
- kůže účinky záření MeSH
- myši bezsrsté MeSH
- myši MeSH
- nádorový supresorový protein p53 účinky záření MeSH
- náhodné rozdělení MeSH
- poškození DNA MeSH
- sluneční záření škodlivé účinky MeSH
- ultrafialové záření škodlivé účinky MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Lymphocytes are among the most radiosensitive cells. After exposure of the organism to ionizing radiation, they promptly die by apoptosis at a rate proportional to the dose received. Because of this, they are frequently used in biodosimetry. We demonstrated that one hour after whole-body irradiation of rats, histone H2AX in the lymphocyte nuclei was quickly phosphorylated on serine 139, the phosphorylation process being directly dependent on the gamma radiation dose. In the work presented here, we studied the kinetics of lymphocyte depletion in the peripheral blood and phosphorylation of histone H2AX in the peripheral blood lymphocytes after local (thoracic) irradiation of rats. Twenty-four hours after whole-body irradiation of the rats at a dose of 5 Gy, the lymphocyte count declined to almost zero values, whereas after local irradiation of the thorax area, the counts of lymphocytes in the peripheral blood remained unaltered. The authors employed two methods (flow-cytometric and microscopic) for the gammaH2AX determination in the peripheral blood lymphocytes, 1 h after thoracic irradiation of rats. Flow cytometry revealed a dose dependence on the increase in gammaH2AX in a dose range of 10-30 Gy. The microscopic method was more sensitive in the case of lower radiation doses, the dependence on the dose being obvious from a dose as low as 5 Gy. The methods are able, in the dose range 5-30 Gy, to differentiate between the type of irradiation, i.e. the whole-body or local.
- MeSH
- apoptóza účinky léků účinky záření MeSH
- buněčné jádro účinky záření MeSH
- celotělové ozáření škodlivé účinky MeSH
- financování organizované MeSH
- fosforylace účinky záření MeSH
- histony účinky záření MeSH
- hrudník cytologie účinky záření MeSH
- imunochemie metody MeSH
- leukocyty mononukleární účinky záření MeSH
- lymfocyty účinky léků účinky záření MeSH
- potkani Wistar MeSH
- průtoková cytometrie využití MeSH
- radiometrie využití MeSH
- statistika jako téma MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
Ionizing radiation and somatostatin analogues are used for acromegaly treatment to achieve normalization or reduction of growth hormone hypersecretion and tumor shrinkage. In this study, we investigated a combination of somatostatin (SS14) with ionizing radiation of (60)Co and its effect on reparation of radiation-induced damage and cell death of somatomammotroph pituitary cells GH3. Doses of gamma-radiation 20-50 Gy were shown to inhibit proliferation and induce apoptosis in GH3 cells regardless of somatostatin presence. It has been found that the D(0) value for GH3 cells was 2.5 Gy. Somatostatin treatment increased radiosensitivity of GH3 cells, so that D(0) value decreased to 2.2 Gy. We detected quick phosphorylation of histone H2A.X upon irradiation by the dose 20 Gy and its colocalization with phosphorylated protein Nbs-1 in the site of double strand break of DNA (DSB). Number of DSB decreased significantly 24 h after irradiation, however, clearly distinguished foci persisted, indicating non repaired DSB, after irradiation alone or after combined treatment by irradiation and SS14. We found that SS14 alone triggers phosphorylation of Nbs1 (p-Nbs1), which correlates with antiproliferative effect of SS14. Irradiation also increased the presence of p-Nbs1. Most intensive phosphorylation of Nbs1 was detected after combined treatment of irradiation and SS14. The decrease of the number of the DSB foci 24 h after treatment shows a significant capacity of repair systems of GH3 cells. In spite of this, large number of unrepaired DSB persists for 24 h after the treatment. We conclude that SS14 does not have a radioprotective effect on somatomammotroph GH3 cells.
- MeSH
- adenom hypofýzy vylučující růstový hormon farmakoterapie chirurgie MeSH
- akromegalie farmakoterapie chirurgie MeSH
- apoptóza genetika účinky záření MeSH
- buněčný cyklus fyziologie účinky záření MeSH
- experimentální radiační poranění prevence a kontrola MeSH
- histony metabolismus účinky záření MeSH
- ionizující záření MeSH
- jaderné proteiny metabolismus účinky záření MeSH
- krysa rodu rattus MeSH
- modely nemocí na zvířatech MeSH
- nádorové buněčné linie MeSH
- nádory hypofýzy farmakoterapie chirurgie MeSH
- neparametrická statistika MeSH
- poškození DNA fyziologie účinky léků MeSH
- potkani Wistar MeSH
- proteiny buněčného cyklu metabolismus účinky záření MeSH
- radiochirurgie škodlivé účinky MeSH
- somatostatin fyziologie terapeutické užití MeSH
- somatotropní buňky metabolismus účinky léků účinky záření MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- MeSH
- acetyltransferasy metabolismus účinky záření MeSH
- elektroforéza v polyakrylamidovém gelu MeSH
- histony genetika metabolismus účinky záření MeSH
- játra enzymologie fyziologie účinky záření MeSH
- krysa rodu rattus MeSH
- regenerace jater MeSH
- stárnutí buněk MeSH
- záření gama škodlivé účinky MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- srovnávací studie MeSH
