Liability to Chromosome Damage in Lymphocytes of “Cancer Family” Subjects: A Study of Spontaneous and Induced Chromosomal Fragility

1987 ◽  
Vol 2 (1) ◽  
pp. 9-17 ◽  
Author(s):  
Lidia Larizza ◽  
Luisa Doneda ◽  
Miria Stefanini ◽  
Giuseppa Francone ◽  
Valter Gualandri ◽  
...  
Keyword(s):  
Chromosomal Instability ◽  
Fragile Sites ◽  
Chromosome 1 ◽  
Chromosome Damage ◽  
Tumor Patients ◽  
Dna Repair Mechanisms ◽  
Chromosomal Fragility ◽  
Repair Mechanisms ◽  
Heterochromatin Polymorphism ◽  
Defective Dna Repair

Spontaneous chromosomal fragility was detected in seven tumor patients and one healthy member from two families with a high recurrence of cancer. Major chromosome lesions, such as terminal deletions and rearranged chromosomes, were found at levels significantly higher than those reported for control individuals. The prevalence of these aberrations in comparison to minor ones (chromosome gaps and chromatid breaks) in this group ofpatients seems to indicate that the fragility observed is the end-point of a process of chromosomal instability, which may have already been brought to expression. Study of other parameters of genetic instability in the most unstable karyotypes showed that the chromosome damage observed was neither paralleled by abnormal SCE frequency nor sustained by defective DNA repair mechanisms or expression of inherited or constitutional fragile sites. As all the subjects investigated here had previously been shown to display intraindividual variations in the C-banded region of chromosome 1, it is possible that spontaneous fragility and acquired C-heterochromatin polymorphism may be markers that, combined with chromosomal instability, create genetic predisposition to cancer.

scholarly journals Cellular Response against Oxidative Stress, a Novel Insight into Lupus Nephritis Pathogenesis

2021 ◽  
Vol 11 (8) ◽  
pp. 693
Author(s):  
Corina Daniela Ene ◽  
Simona Roxana Georgescu ◽  
Mircea Tampa ◽  
Clara Matei ◽  
Cristina Iulia Mitran ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lupus Nephritis ◽  
Cellular Response ◽  
Molecular Mechanisms ◽  
Control Group ◽  
Dna Repair Mechanisms ◽  
Glycation End Products ◽  
Repair Mechanisms ◽  
Low Levels ◽  
Defective Dna Repair

The interaction of reactive oxygen species (ROS) with lipids, proteins, nucleic acids and hydrocarbonates promotes acute and chronic tissue damage, mediates immunomodulation and triggers autoimmunity in systemic lupus erythematous (SLE) patients. The aim of the study was to determine the pathophysiological mechanisms of the oxidative stress-related damage and molecular mechanisms to counteract oxidative stimuli in lupus nephritis. Our study included 38 SLE patients with lupus nephritis (LN group), 44 SLE patients without renal impairment (non-LN group) and 40 healthy volunteers as control group. In the present paper, we evaluated serum lipid peroxidation, DNA oxidation, oxidized proteins, carbohydrate oxidation, and endogenous protective systems. We detected defective DNA repair mechanisms via 8-oxoguanine-DNA-glycosylase (OGG1), the reduced regulatory effect of soluble receptor for advanced glycation end products (sRAGE) in the activation of AGE-RAGE axis, low levels of thiols, disulphide bonds formation and high nitrotyrosination in lupus nephritis. All these data help us to identify more molecular mechanisms to counteract oxidative stress in LN that could permit a more precise assessment of disease prognosis, as well as developing new therapeutic targets.

scholarly journals Immunodeficiency, centromeric heterochromatin instability of chromosomes 1, 9, and 16, and facial anomalies: the ICF syndrome

2017 ◽  
Vol 4 (4) ◽  
pp. 1545
Author(s):  
Shailesh Pande ◽  
Mani Bhushan ◽  
Anurita Pais ◽  
Gauri Pradhan ◽  
Chaitali Kadam ◽  
...  
Keyword(s):  
Chromosomal Instability ◽  
Immune Status ◽  
Centromeric Region ◽  
Fragile Sites ◽  
Chromosome 1 ◽  
Centromeric Heterochromatin ◽  
Reference Laboratory ◽  
Icf Syndrome ◽  
Facial Anomalies ◽  
Chromosomal Data

Instability of the heterochromatic centromeric regions of chromosomes 1 associated with immunodeficiency was found in a 3 and half months old girl. The case was referred to Department of Genetics, Global Reference Laboratory, Metropolis Healthcare Ltd, Mumbai with the suspicion of Downs Syndrome for chromosomal karyotyping. This patient had facial anomalies in addition to combined immunodeficiency and chromosomal instability. Stretching of the heterochromatic centromeric regions of chromosomes 1 and homologous and non-homologous associations of these regions were the most common cytogenetic findings in this patient. Multi-branched configurations and whole arm deletions of chromosomes 1 were also found. Comparing clinical and chromosomal data we conclude that the patient was suffering from immunodeficiency, centromeric heterochromatin instability and facial syndrome. The chromosomal karyotyping report was showing instability around vicinity of chromosome 1 and various abnormalities around vicinity of both chromosomes 1 were found in form of random breakages of chromosome 1, fragile sites, deletions/duplications of small and long arm, extra copies of chromosome 1 with rosette formations, exchange of arms and partial aneuploidies of chromosome 1. Further, the investigations regarding the immune status revealed that the level of IgM (5.98 mg/dl), IgA (<6.16mg/dl) and IgG (92.10 mg/dl) subgroup of immunoglobulin was very low. The results were consistent with The Immunodeficiency, Centromeric region instability, Facial anomalies (ICF) syndrome. Second sample from the patient for molecular studies could not be collected and performed since the patient failed to survive after 3 and half months.

scholarly journals Defective DNA repair mechanisms in prostate cancer: impact of olaparib

2017 ◽  
Vol Volume11 ◽  
pp. 547-552 ◽  
Author(s):  
Francesca De Felice ◽  
Vincenzo Tombolini ◽  
Francesco Marampon ◽  
Angela Musella ◽  
Claudia Marchetti
Keyword(s):  
Prostate Cancer ◽  
Dna Repair ◽  
Dna Repair Mechanisms ◽  
Repair Mechanisms ◽  
Defective Dna Repair

scholarly journals Replication Timing and Transcription Identifies a Novel Fragility Signature Under Replication Stress

2019 ◽  
Author(s):  
Dan Sarni ◽  
Takayo Sasaki ◽  
Karin Miron ◽  
Michal Irony Tur-Sinai ◽  
Juan Carlos Rivera-Mulia ◽  
...  
Keyword(s):  
Dna Replication ◽  
Chromosomal Instability ◽  
Temporal Order ◽  
Replication Timing ◽  
Replication Stress ◽  
Fragile Sites ◽  
Precise Mapping ◽  
Chromosomal Fragility ◽  
Transcriptional Changes ◽  
Large Genes

AbstractCommon fragile sties (CFSs) are regions susceptible to replication stress and are hotspots for chromosomal instability in cancer. Several features characterizing CFSs have been associated with their instability, however, these features are prevalent across the genome and do not account for all known CFSs. Therefore, the molecular mechanism underlying CFS instability remains unclear. Here, we explored the transcriptional profile and temporal order of DNA replication (replication timing, RT) of cells under replication stress conditions. We show that the RT of only a small portion of the genome is affected by replication stress, and that CFSs are enriched for delayed RT. We identified a signature for chromosomal fragility, comprised of replication stress-induced delay in RT of early/mid S-phase replicating regions within actively transcribed large genes. This fragility signature enabled precise mapping of the core fragility region. Furthermore, the signature enabled the identification of novel fragile sites that were not detected cytogenetically, highlighting the improved sensitivity of our approach for identifying fragile sites. Altogether, this study reveals a link between altered DNA replication and transcription of large genes underlying the mechanism of CFS expression. Thus, investigating the RT and transcriptional changes in cancer may contribute to the understanding of mechanisms promoting genomic instability in cancer.

scholarly journals PARP Inhibitors and Haematological Malignancies—Friend or Foe?

Cancers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 5328
Author(s):  
Kathryn A. Skelding ◽  
Lisa F. Lincz
Keyword(s):  
Gene Mutations ◽  
Standard Of Care ◽  
Parp Inhibitors ◽  
Haematological Malignancies ◽  
Brca Mutations ◽  
Dna Repair Mechanisms ◽  
Repair Mechanisms ◽  
Defective Dna Repair ◽  
Potential Use

Since their introduction several years ago, poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi) have become the standard of care for breast and gynaecological cancers with BRCA gene mutations. Given that PARPi act by exploiting defective DNA repair mechanisms within tumour cells, they should be ideally suited to combatting haematological malignancies where these pathways are notoriously defective, even though BRCA mutations are rare. To date, despite promising results in vitro, few clinical trials in humans for haematological malignancies have been performed, and additional investigation is required. Paradoxically, secondary haematological malignancies have arisen in patients after treatment with PARPi, raising concerns about their potential use as therapies for any blood or bone marrow-related disorders. Here, we provide a comprehensive review of the biological, pre-clinical, and clinical evidence for and against treating individual haematological malignancies with approved and experimental PARPi. We conclude that the promise of effective treatment still exists, but remains limited by the lack of investigation into useful biomarkers unique to these malignancies.

scholarly journals DNA Damage Response in Multiple Myeloma: The Role of the Tumor Microenvironment

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 504
Author(s):  
Takayuki Saitoh ◽  
Tsukasa Oda
Keyword(s):  
Multiple Myeloma ◽  
Dna Damage ◽  
Dna Repair ◽  
Tumor Microenvironment ◽  
Dna Damage Response ◽  
Genetic Instability ◽  
Dna Repair Mechanisms ◽  
Damage Response ◽  
Repair Mechanisms

Multiple myeloma (MM) is an incurable plasma cell malignancy characterized by genomic instability. MM cells present various forms of genetic instability, including chromosomal instability, microsatellite instability, and base-pair alterations, as well as changes in chromosome number. The tumor microenvironment and an abnormal DNA repair function affect genetic instability in this disease. In addition, states of the tumor microenvironment itself, such as inflammation and hypoxia, influence the DNA damage response, which includes DNA repair mechanisms, cell cycle checkpoints, and apoptotic pathways. Unrepaired DNA damage in tumor cells has been shown to exacerbate genomic instability and aberrant features that enable MM progression and drug resistance. This review provides an overview of the DNA repair pathways, with a special focus on their function in MM, and discusses the role of the tumor microenvironment in governing DNA repair mechanisms.

scholarly journals Ancient Sturgeons Possess Effective DNA Repair Mechanisms: Influence of Model Genotoxicants on Embryo Development of Sterlet, Acipenser ruthenus

2020 ◽  
Vol 22 (1) ◽  
pp. 6
Author(s):  
Ievgeniia Gazo ◽  
Roman Franěk ◽  
Radek Šindelka ◽  
Ievgen Lebeda ◽  
Sahana Shivaramu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Damage ◽  
Dna Repair ◽  
Embryo Development ◽  
Hatching Rate ◽  
Embryo Survival ◽  
Dna Repair Mechanisms ◽  
Acipenser Ruthenus ◽  
Repair Mechanisms ◽  
Sterlet Acipenser Ruthenus

DNA damage caused by exogenous or endogenous factors is a common challenge for developing fish embryos. DNA damage repair (DDR) pathways help organisms minimize adverse effects of DNA alterations. In terms of DNA repair mechanisms, sturgeons represent a particularly interesting model due to their exceptional genome plasticity. Sterlet (Acipenser ruthenus) is a relatively small species of sturgeon. The goal of this study was to assess the sensitivity of sterlet embryos to model genotoxicants (camptothecin, etoposide, and benzo[a]pyrene), and to assess DDR responses. We assessed the effects of genotoxicants on embryo survival, hatching rate, DNA fragmentation, gene expression, and phosphorylation of H2AX and ATM kinase. Exposure of sterlet embryos to 1 µM benzo[a]pyrene induced low levels of DNA damage accompanied by ATM phosphorylation and xpc gene expression. Conversely, 20 µM etoposide exposure induced DNA damage without activation of known DDR pathways. Effects of 10 nM camptothecin on embryo development were stage-specific, with early stages, before gastrulation, being most sensitive. Overall, this study provides foundational information for future investigation of sterlet DDR pathways.

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