Search results for "chromosome aberration"
showing 10 items of 160 documents
Concentration-Dependent Protection by Ethanol Extract ofPropolis against γ
2011
[EN] Radioprotection with natural products may be relevant to the mitigation of ionizing radiation-induced damage in mammalian systems; in this sense, propolis extracts have shown effects such as antioxidant, antitumoral, anti-inflammatory, and immunostimulant. We report for the first time a cytogenetic study to evaluate the radioprotective effect, in vitro, of propolis against radiation-induced chromosomal damage. Lymphocytes were cultured with increasing concentrations of ethanol extract of propolis (EEP), including 20, 40, 120, 250, 500, 750, 1000, and 2000 ¿g mL-1 and then exposed to 2 Gy ¿-rays. A significant and concentration-dependent decrease is observed in the frequency of chromoso…
Cytogenetic characterization of HB2 epithelial cells from the human breast.
2014
HB2 is a cell line originated by subcloning of MTSV1-7 mammary luminal epithelial cells isolated from human milk and immortalization via introduction of the gene encoding simian virus 40 (SV40) large T antigen. Despite its wide utilization as non-neoplastic counterpart in assays aimed to elucidating various biochemical and genetical aspects of normal and tumoral breast cells, to our knowledge no literature data have so far appeared concerning the chromosomal characterization of the HB2 cells. Here, we report the cytogenetic characterization of the karyotype of HB2 cells, which puts in evidence the occurrence of changes in chromosomal number and structure and the presence of unidentified chr…
A region on human chromosome 4 (q35.1→qter) induces senescence in cell hybrids and is involved in cervical carcinogenesis
2005
Human papillomavirus (HPV) types 16 and 18 are known to play a major role in cervical carcinogenesis. Additional genetic alterations are required for the development and progression of cervical cancer. Previously, we showed that the introduction of an entire human chromosome 4 into HPV-immortalized cells by microcell-mediated chromosome transfer (MMCT) can induce senescence in cell hybrids. In the present study, we established eight new murine donor cell lines harboring different fragments of the human chromosome 4. These were tested for their ability to induce senescence by MMCT into HPV16-immortalized keratinocytes (HPK II) and cervical carcinoma cells (HeLa). By exclusion, we could ident…
The genetic tumor background is an important determinant for heterogeneous MYCN ‐amplified neuroblastoma
2016
Amplification of MYCN is the signature genetic aberration of 20–25% of neuroblastoma and a stratifying marker associated with aggressive tumor behavior. The detection of heterogeneous MYCN amplification (hetMNA) poses a diagnostic dilemma due to the uncertainty of its relevance to tumor behavior. Here, we aimed to shed light on the genomic background which permits hetMNA in neuroblastoma and tied the occurrence to other stratifying markers and disease outcome. We performed SNP analysis using Affymetrix Cytoscan HD arrays on 63 samples including constitutional DNA, tumor, bone marrow and relapse samples of 26 patients with confirmed hetMNA by MYCN‐FISH. Tumors of patients ≤18m were mostly an…
Imbalance between genomic gain and loss identifies high-risk neuroblastoma patients with worse outcomes
2021
Survival in high-risk neuroblastoma (HR-NB) patients remains poor despite multimodal treatment. We aimed to identify HR-NB patients with worse outcomes by analyzing the genomic instability derived from segmental chromosomal aberrations. We calculated 3 genomic instability indexes for primary tumor SNP array profiles from 127 HR-NB patients: (1) Copy number aberration burden (%gainslength+%losseslength), (2) copy number load (CNL) (%gainslength-%losseslength) and (3) net genomic load (NGL) (%gainsamount-%lossesamount). Tumors were classified according to positive or negative CNL and NGL genomic subtypes. The impact of the genomic instability indexes on overall survival (OS) was assessed with…
Influence of GSM signals on human peripheral lymphocytes: study of genotoxicity.
2013
Exposure to radiofrequency (RF) electromagnetic fields (EMF) is continuously increasing worldwide. Yet, conflicting results of a possible genotoxic effect of RF EMF continue to be discussed. In the present study, a possible genotoxic effect of RF EMF (GSM, 1,800 MHz) in human lymphocytes was investigated by a collaboration of six independent institutes (institutes a, b, c, d, e, h). Peripheral blood of 20 healthy, nonsmoking volunteers of two age groups (10 volunteers 16-20 years old and 10 volunteers 50-65 years old) was taken, stimulated and intermittently exposed to three specific absorption rates (SARs) of RF EMF (0.2 W/kg, 2 W/kg, 10 W/kg) and sham for 28 h (institute a). The exposures…
Frequency of dicentrics and contamination levels in Ukrainian children and adolescents from areas near Chernobyl 20 years after the nuclear plant acc…
2013
International audience; Purpose To survey the possible presence of chromosomal damage and internal contamination in a group of Ukrainian children and adolescents, 20 years after the Chernobyl accident at the Nuclear Power Plant. Materials and methods Cytogenetical procedures were performed according to dicentric assay in 55 Ukrainian children and adolescents (29 boys and 26 girls), living near Chernobyl. In addition, a whole body detector and urinalysis were used to detect internal contamination. Results 36 dicentrics were found in a total of 53,477 metaphases scored in these children, which reflected a frequency of dicentrics below the background level. On the other hand, internal contamin…
A conserved role for the mitochondrial citrate transporter Sea/SLC25A1 in the maintenance of chromosome integrity.
2009
Histone acetylation plays essential roles in cell cycle progression, DNA repair, gene expression and silencing. Although the knowledge regarding the roles of acetylation of histone lysine residues is rapidly growing, very little is known about the biochemical pathways providing the nucleus with metabolites necessary for physiological chromatin acetylation. Here, we show that mutations in the scheggia (sea)-encoded Sea protein, the Drosophila ortholog of the human mitochondrial citrate carrier Solute carrier 25 A1 (SLC25A1), impair citrate transport from mitochondria to the cytosol. Interestingly, inhibition of sea expression results in extensive chromosome breakage in mitotic cells and indu…
Amplification of ETS2 oncogene in acute nonlymphoblastic leukemia with t(6;21;18).
1992
Cytogenetic and molecular studies in a case of acute nonlymphoblastic leukemia (ANLL) are reported in this paper. Bone marrow blasts carried a hypodiploid karyotype with a complex t(6;18;21)(6qter----6p21::21q22----21qter;18qter ----18p11::6p22----6pter; 21pter----21q22::6p21----6p22::18p11----18pte r) and other numerical and structural changes. We studied the organization and the expression of the ETS2 gene which is located on chromosome 21 in order to investigate its possible involvement in the disease. DNA analysis showed a 20-fold amplification of ETS2 sequences; an increase of 3- to 4-fold in the mRNAs level compared to normal was shown by Northern hybridization.
Neuroblastoma after Childhood: Prognostic Relevance of Segmental Chromosome Aberrations, ATRX Protein Status, and Immune Cell Infiltration
2014
AbstractNeuroblastoma (NB) is a common malignancy in children but rarely occurs during adolescence or adulthood. This subgroup is characterized by an indolent disease course, almost uniformly fatal, yet little is known about the biologic characteristics. The aim of this study was to identify differential features regarding DNA copy number alterations, α-thalassemia/mental retardation syndrome X-linked (ATRX) protein expression, and the presence of tumor-associated inflammatory cells. Thirty-one NB patients older than 10 years who were included in the Spanish NB Registry were considered for the current study; seven young and middle-aged adult patients (range 18-60 years) formed part of the c…