Interchromosomal distribution of gamma ray-induced chromatid aberrations in Chinese hamster ovary cells

Martínez‐López, Wilner; Porro, V.; Folle, Gustavo A.; Méndez-Acuña, L.; Savage, John R. K.; Obe, Günter

doi:10.1590/s1415-47572000000400053

Cited by 12 publications

(8 citation statements)

References 26 publications

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“…Cells were cultivated in McCoy’s 5A Medium supplemented with 10% fetal calf serum, penicillin (100 units mL −1 ), streptomycin (100 µg mL −1 ), and L-glutamin (7.5 mL L −1 ). Cells, cell culture conditions and the preparation of metaphase chromosomes were described earlier [ 144 – 145 ]. Metaphase plates scored for sister-chromatid exchanges are stained by using the Fluorescence-plus-Giemsa (FPG) protocol.…”

Section: Methodsmentioning

confidence: 99%

PVP-coated, negatively charged silver nanoparticles: A multi-center study of their physicochemical characteristics, cell culture and in vivo experiments

Ahlberg¹,

Antonopulos²,

Diendorf³

et al. 2014

Beilstein J. Nanotechnol.

119

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SummaryPVP-capped silver nanoparticles with a diameter of the metallic core of 70 nm, a hydrodynamic diameter of 120 nm and a zeta potential of −20 mV were prepared and investigated with regard to their biological activity. This review summarizes the physicochemical properties (dissolution, protein adsorption, dispersability) of these nanoparticles and the cellular consequences of the exposure of a broad range of biological test systems to this defined type of silver nanoparticles. Silver nanoparticles dissolve in water in the presence of oxygen. In addition, in biological media (i.e., in the presence of proteins) the surface of silver nanoparticles is rapidly coated by a protein corona that influences their physicochemical and biological properties including cellular uptake. Silver nanoparticles are taken up by cell-type specific endocytosis pathways as demonstrated for hMSC, primary T-cells, primary monocytes, and astrocytes. A visualization of particles inside cells is possible by X-ray microscopy, fluorescence microscopy, and combined FIB/SEM analysis. By staining organelles, their localization inside the cell can be additionally determined. While primary brain astrocytes are shown to be fairly tolerant toward silver nanoparticles, silver nanoparticles induce the formation of DNA double-strand-breaks (DSB) and lead to chromosomal aberrations and sister-chromatid exchanges in Chinese hamster fibroblast cell lines (CHO9, K1, V79B). An exposure of rats to silver nanoparticles in vivo induced a moderate pulmonary toxicity, however, only at rather high concentrations. The same was found in precision-cut lung slices of rats in which silver nanoparticles remained mainly at the tissue surface. In a human 3D triple-cell culture model consisting of three cell types (alveolar epithelial cells, macrophages, and dendritic cells), adverse effects were also only found at high silver concentrations. The silver ions that are released from silver nanoparticles may be harmful to skin with disrupted barrier (e.g., wounds) and induce oxidative stress in skin cells (HaCaT). In conclusion, the data obtained on the effects of this well-defined type of silver nanoparticles on various biological systems clearly demonstrate that cell-type specific properties as well as experimental conditions determine the biocompatibility of and the cellular responses to an exposure with silver nanoparticles.

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Section: Methodsmentioning

confidence: 99%

PVP-coated, negatively charged silver nanoparticles: A multi-center study of their physicochemical characteristics, cell culture and in vivo experiments

Ahlberg¹,

Antonopulos²,

Diendorf³

et al. 2014

Beilstein J. Nanotechnol.

119

View full text Add to dashboard Cite

show abstract

“…To reconstitute the pseudo-colored karyotype, several images from CHO9 and XR-C1B cells were processed and analyzed with Genus (Applied Imaging, Cambridge UK) or ISIS software (Metasystems S.A., Germany). The classification of chromosomes was made according to the published G-banded karyotype of CHO9 cells with rearranged chromosomes mentioned as Z markers (Martinez-Lopez et al 2000).…”

Section: Cell Culture and Irradiationmentioning

confidence: 99%

Different DNA-PKcs functions in the repair of radiation-induced and spontaneous DSBs within interstitial telomeric sequences

et al. 2011

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Interstitial telomeric sequences (ITSs) in hamster cells are hot spots for spontaneous and induced chromosome aberrations (CAs). Most data on ITS instability to date have been obtained in DNA repair-proficient cells. The classical non-homologous end joining repair pathway (C-NHEJ), which is the principal double strand break (DSB) repair mechanism in mammalian cells, is thought to restore the morphologically correct chromosome structure. The production of CAs thus involves DNA-PKcs-independent repair pathways. In our current study, we investigated the participation of DNA-PKcs from the C-NHEJ pathway in the repair of spontaneous or radiation-induced DSBs in ITSs using wild-type and DNA-PKcs mutant Chinese hamster ovary cells. Our data demonstrate that DNA-PKcs stabilizes spontaneous DSBs within ITSs from the chromosome 9 long arm, leading to the formation of terminal deletions. In addition, we show that DNA-PKcs-dependent C-NHEJ is employed following radiation-induced DSBs in other ITSs and restores morphologically correct chromosomes, whereas DNA-PKcs independent mechanisms co-exist in DNA-PKcs proficient cells leading to an excess of CAs within ITSs.

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“…A non-random distribution of SORB along Chinese hamster chromosomes was found by several authors. Additionally, a preferential induction of SORB in specific chromosome regions was also described (Slijepcevic and Natarajan, 1994a, b;Dominguez et al, 1996;Grigorova et al, 1998;Xiao and Natarajan, 1999a, b, c;Martínez-Ló pez et al, 2000). Xiao and Natarajan (1999a) studied the frequencies and distribution of X-ray-induced CA in Chinese hamster primary fibroblasts by fluorescence in situ hybridization (FISH) during the G1 phase of the cell cycle.…”

Section: Discussionmentioning

confidence: 99%

Distribution of breakpoints induced by etoposide and X-rays along the CHO X chromosome

Martínez‐López

Folle

Cassina

et al. 2004

Cytogenet Genome Res

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SORB (selected observed residual breakpoints) induced by ionizing radiation or endonucleases are often non-randomly distributed in mammalian chromosomes. However, the role played by chromatin structure in the localization of chromosome SORB is not well understood. Anti-topoisomerase drugs such as etoposide are potent clastogens and unlike endonucleases or ionizing radiation, induce DNA double-strand breaks (DSB) by an indirect mechanism. Topoisomerase II (Topo II) is a main component of the nuclear matrix and the chromosome scaffold. Since etoposide leads to DSB by influencing the activity of Topo II, this compound may be a useful tool to study the influence of the chromatin organization on the distribution of induced SORB in mammalian chromosomes. In the present work, we compared the distribution of SORB induced during S-phase by etoposide or X-rays in the short euchromatic and long heterochromatic arms of the CHO9 X chromosome. The S-phase stage (early, mid or late) at which CHO9 cells were exposed to etoposide or X-rays was marked by incorporation of BrdU during treatments and later determined by immunolabeling of metaphase chromosomes with an anti-BrdU FITC-coupled antibody. The majority of treated cells were in late S-phase during treatment either with etoposide or X-rays. SORB induced by etoposide mapped preferentially to Xq but random localization was observed for SORB produced by X-rays. Possible explanations for the uneven distribution of etoposide-induced breakpoints along Xq are discussed.

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Interchromosomal distribution of gamma ray-induced chromatid aberrations in Chinese hamster ovary cells

Cited by 12 publications

References 26 publications

PVP-coated, negatively charged silver nanoparticles: A multi-center study of their physicochemical characteristics, cell culture and in vivo experiments

PVP-coated, negatively charged silver nanoparticles: A multi-center study of their physicochemical characteristics, cell culture and in vivo experiments

Different DNA-PKcs functions in the repair of radiation-induced and spontaneous DSBs within interstitial telomeric sequences

Distribution of breakpoints induced by etoposide and X-rays along the CHO X chromosome

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