Purpose: Insulin-like growth factor-1 (IGF-1) stimulates epithelial regeneration but may also induce life-threatening hypoglycemia. In our study, we first assessed its safety. Subsequently, we examined the effect of IGF-1 administered in different dose regimens on gastrointestinal damage induced by high doses of gamma radiation. Material and methods: First, fasting C57BL/6 mice were injected subcutaneously with IGF-1 at a single dose of 0, 0.2, 1, and 2 mg/kg to determine the maximum tolerated dose (MTD). The glycemic effect of MTD (1 mg/kg) was additionally tested in non-fasting animals. Subsequently, a survival experiment was performed. Animals were irradiated (60Co; 14, 14.5, or 15 Gy; shielded head), and IGF-1 was administered subcutaneously at 1 mg/kg 1, 24, and 48 h after irradiation. Simultaneously, mice were irradiated (60Co; 12, 14, or 15 Gy; shielded head), and IGF-1 was administered subcutaneously under the same regimen. Jejunum and lung damage were assessed 84 h after irradiation. Finally, we evaluated the effect of six different IGF-1 dosage regimens administered subcutaneously on gastrointestinal damage and peripheral blood changes in mice 6 days after irradiation (60Co; 12 and 14 Gy; shielded head). The regimens differed in the number of doses (one to five doses) and the onset of administration (starting at 1 [five regimens] or 24 h [one regimen] after irradiation). Results: MTD was established at 1 mg/kg. MTD mitigated lethality induced by 14 Gy and reduced jejunum and lung damage caused by 12 and 14 Gy. However, different dosing regimens showed different efficacy, with three and four doses (administered 1, 24, and 48 h and 1, 24, 48, and 72 h after irradiation, respectively) being the most effective. The three-dose regimens supported intestinal regeneration even if the administration started at 24 h after irradiation, but its potency decreased. Conclusion: IGF-1 seems promising in the mitigation of high-dose irradiation damage. However, the selected dosage regimen affects its efficacy.

• Publikační typ
• časopisecké články MeSH

The aim of this study was to compare the effects of DNA repair inhibitors in the context of radio-sensitization of human lung cells. The radio-sensitizing effects of NU7441 (1 mM), an inhibitor of DNA-dependent protein kinase (DNA-PK); KU55933 (10 μM), an inhibitor of ataxia-telangiectasia mutated kinase (ATM); and VE-821 (10 μM), an inhibitor of ATM-related kinase (ATR) were tested by the xCELLigence system for monitoring proliferation, fluorescence microscopy for DNA damage detection, flow-cytometry for cell cycle and apoptosis analysis and western blotting and ELISA for determination of DNA repair proteins. We employed normal human lung fibroblasts (NHLF, p53-wild-type) and non-small cell lung cancer cells (H1299, p53-negative). DNA-PK inhibition (by NU7441) in combination with ionizing radiation (IR) increased the number of double strand breaks (DSB), which persisted 72 h after irradiation in both cell lines. Additionally, NU7441 and KU55933 in combination with IR caused G2-arrest. ATR inhibitor (VE-821) together with IR markedly inhibited proliferation and induced G2/M arrest accompanied by apoptosis in H1299, but not in NHLF cells, and thus diminished DNA-repair of tumour cells but not normal lung fibroblasts. Our findings indicate that ATR inhibition could be a promising therapeutic strategy in p53-deficient lung tumours.

• MeSH
• enzymy opravy DNA antagonisté a inhibitory   genetika   MeSH
• fibroblasty účinky záření   MeSH
• kultivované buňky účinky záření   MeSH
• nádorové buňky kultivované účinky léků   účinky záření   MeSH
• nemalobuněčný karcinom plic genetika   radioterapie   MeSH
• oprava DNA účinky léků   MeSH
• proliferace buněk účinky záření   MeSH
• radiosenzibilizující látky farmakologie   izolace a purifikace   terapeutické užití   MeSH
• techniky in vitro MeSH
• Publikační typ
• práce podpořená grantem MeSH

The increasing risk of acute large-scale radiological/nuclear exposures of population underlines the necessity of developing new, rapid and high throughput biodosimetric tools for estimation of received dose and initial triage. We aimed to compare the induction and persistence of different radiation exposure biomarkers in human peripheral blood in vivo. Blood samples of patients with indicated radiotherapy (RT) undergoing partial body irradiation (PBI) were obtained soon before the first treatment and then after 24 h, 48 h, and 5 weeks; i.e. after 1, 2, and 25 fractionated RT procedures. We collected circulating peripheral blood from ten patients with tumor of endometrium (1.8 Gy per fraction) and eight patients with tumor of head and neck (2.0-2.121 Gy per fraction). Incidence of dicentrics and micronuclei was monitored as well as determination of apoptosis and the transcription level of selected radiation-responsive genes. Since mitochondrial DNA (mtDNA) has been reported to be a potential indicator of radiation damage in vitro, we also assessed mtDNA content and deletions by novel multiplex quantitative PCR. Cytogenetic data confirmed linear dose-dependent increase in dicentrics (p < 0.01) and micronuclei (p < 0.001) in peripheral blood mononuclear cells after PBI. Significant up-regulations of five previously identified transcriptional biomarkers of radiation exposure (PHPT1, CCNG1, CDKN1A, GADD45, and SESN1) were also found (p < 0.01). No statistical change in mtDNA deletion levels was detected; however, our data indicate that the total mtDNA content decreased with increasing number of RT fractions. Interestingly, the number of micronuclei appears to correlate with late radiation toxicity (r2 = 0.9025) in endometrial patients suggesting the possibility of predicting the severity of RT-related toxicity by monitoring this parameter. Overall, these data represent, to our best knowledge, the first study providing a multiparametric comparison of radiation biomarkers in human blood in vivo, which have potential for improving biological dosimetry.

• MeSH
• biologické markery krev   MeSH
• celková dávka radioterapie MeSH
• chromozomální aberace MeSH
• genetická transkripce účinky záření   MeSH
• leukocyty patologie   účinky záření   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mikrojádra chromozomálně defektní MeSH
• mitochondriální DNA účinky záření   MeSH
• nádory endometria krev   radioterapie   MeSH
• nádory hlavy a krku krev   radioterapie   MeSH
• radiační expozice * MeSH
• radiometrie metody   MeSH
• radioterapie škodlivé účinky   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• vztah dávky záření a odpovědi MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

• Publikační typ
• abstrakt z konference MeSH

We examined the effect of epidermal growth factor (EGF) treatment in mice that received bone marrow transplantation (BMT) after 11 Gy whole-body irradiation. C57Bl/6 mice were divided into three treatment groups: 0 Gy; 11 Gy ((60)Co, single dose, 0.51 Gy/min) with BMT (5 × 10(6) bone marrow cells isolated from green fluorescent protein syngeneic mice, 3-4 h postirradiation); and 11 Gy with BMT and EGF (2 mg/kg applied subcutaneously 1, 3 and 5 days postirradiation). Survival data were collected. Bone marrow, peripheral blood count and cytokines, gastrointestine and liver parameters and migration of green fluorescent protein-positive cells were evaluated at 63 days postirradiation. Epidermal growth factor increased survival of irradiated animals that received BMT from 10.7 to 85.7% at 180 days postirradiation. In the BMT group, we found changes in differential bone marrow and blood count, plasma cytokine levels, gastrointestinal tissues and liver at 63 days postirradiation. These alterations were completely or in some parameters at least partially restored by epidermal growth factor. These findings indicate that epidermal growth factor, administered 1, 3 and 5 days postirradiation in combination with bone marrow transplantation, significantly improves long-term prognosis.

• MeSH
• apoptóza účinky léků   účinky záření   MeSH
• bezpečnost MeSH
• časové faktory MeSH
• celotělové ozáření škodlivé účinky   MeSH
• cytokiny krev   MeSH
• epidermální růstové faktory farmakologie   MeSH
• kostní dřeň účinky léků   imunologie   účinky záření   MeSH
• mitóza účinky léků   účinky záření   MeSH
• myši MeSH
• počet buněk MeSH
• radiační poranění krev   farmakoterapie   patologie   terapie   MeSH
• slezina účinky léků   patologie   účinky záření   MeSH
• střeva účinky léků   patologie   účinky záření   MeSH
• transplantace kostní dřeně * MeSH
• velikost orgánu účinky léků   účinky záření   MeSH
• vztah dávky záření a odpovědi MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články 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 účinky záření   MeSH
• fosforylace imunologie   účinky záření   MeSH
• histony chemie   účinky záření   MeSH
• inhibitory fosfoinositid-3-kinasy 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

PURPOSE: We examined the effect of epidermal growth factor (EGF) and bone marrow transplantation (BMT) on gastrointestinal damage after high-dose irradiation of mice. MATERIAL AND METHODS: C57Black/6 mice were used. Two survival experiments were performed (12 and 13 Gy; (60)Co, 0.59-0.57 Gy/min). To evaluate BMT and EGF action, five groups were established - 0 Gy, 13 Gy, 13 Gy + EGF (at 2 mg/kg, first dose 24 h after irradiation and then every 48 h), 13 Gy + BMT (5 × 10(6) cells from green fluorescent protein [GFP] syngenic mice, 4 h after irradiation), and 13 Gy + BMT + EGF. Survival data, blood cell counts, gastrointestine and liver parameters and GFP positive cell migration were measured. RESULTS: BMT and EGF (three doses, at 2 mg/kg, administered 1, 3 and 5 days after irradiation) significantly increased survival (13 Gy). In blood, progressive cytopenia was observed with BMT, EGF or their combination having no improving effect early after irradiation. In gastrointestinal system, BMT, EGF and their combination attenuated radiation-induced atrophy and increased regeneration during first week after irradiation with the combination being most effective. Signs of systemic inflammatory reaction were observed 30 days after irradiation. CONCLUSIONS: Our data indicate that BMT together with EGF is a promising strategy in the treatment of high-dose whole-body irradiation damage.

• MeSH
• apoptóza účinky léků   účinky záření   MeSH
• celotělové ozáření škodlivé účinky   MeSH
• epidermální růstový faktor aplikace a dávkování   terapeutické užití   MeSH
• experimentální radiační poranění farmakoterapie   patologie   terapie   MeSH
• gastrointestinální trakt zranění   patologie   účinky záření   MeSH
• kombinovaná terapie MeSH
• lithostatin účinky léků   MeSH
• mitóza účinky léků   účinky záření   MeSH
• myši inbrední C57BL MeSH
• myši transgenní MeSH
• myši MeSH
• transplantace kostní dřeně * MeSH
• zánět patologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH