scholarly journals Acute Toxicity and DNA Instability Induced by Exposure to Low Doses of Triclosan and Phthalate DEHP, and Their Combinations, in vitro

2021 ◽  
Vol 12 ◽  
Author(s):  
Nathalia de Assis Aguilar Duarte ◽  
Lindiane Eloisa de Lima ◽  
Flora Troina Maraslis ◽  
Michael Kundi ◽  
Emilene Arusievicz Nunes ◽  
...  
Keyword(s):  
Dna Damage ◽  
Acute Toxicity ◽  
Nuclear Division ◽  
Aquatic Organisms ◽  
Human Cells ◽  
Dna Instability ◽  
Nuclear Division Index ◽  
Mutagenic Effects ◽  
The Impact

Triclosan (TCS) is an antimicrobial agent widely used in personal care products (PCP) and the di-(2-ethyl hydroxy-phthalate) (DEHP) is a chemical compound derived from phthalic acid, used in medical devices and plastic products with polyvinyl chloride (PVCs). As result of their extensive use, TCS and DEHP have been found in the environment and previous studies demonstrated the association between their exposure and toxic effects, mostly in aquatic organisms, but there is a shortage in the literature concerning the exposure of TCS and DEHP in human cells. The aim of the present study was to assess the impact of exposure to TCS and DEHP, as well as their combinations, on biomarkers related to acute toxicity and DNA instability, in HepG2 cells, by use of cytokinesis-block micronucleus cytome (CBMNCyt) assay. For that, the cultures were exposed to TCS, DEHP and combinations at doses of 0.10, 1.0, and 10 μM for the period of 4 h and the parameters related to DNA damage (i.e., frequencies of micronuclei (MN) and nuclear buds (NBUDs), to cell division (i.e., nuclear division index (NDI) and nuclear division cytotoxic index (NDCI) and to cell death (apoptotic and necrotic cells) were scored. Clear mutagenic effects were seen in cells treated with TCS, DEHP at doses of 1.0 and 10 μM, but no combined effects were observed when the cells were exposed to the combinations of TCS + DEHP. On the other hand, the combination of the toxicants significantly increased the frequencies of apoptotic and necrotic cells, as well as induced alterations of biomarkers related to cell viability (NDI and NDCI), when compared to the groups treated only with TCS or DEHP. Taken together, the results showed that TCS and DEHP are also able to induce acute toxicity and DNA damage in human cells.

scholarly journals DNA damage and mutation in human cells exposed to nitric oxide in vitro.

1992 ◽  
Vol 89 (7) ◽  
pp. 3030-3034 ◽  
Author(s):  
T. Nguyen ◽  
D. Brunson ◽  
C. L. Crespi ◽  
B. W. Penman ◽  
J. S. Wishnok ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Dna Damage ◽  
Human Cells

A Novel Animal Model for Detecting Damage to Human Platelet Transfusion Products: In Vivo Recovery and Survival in Severe Combined Immunodeficient Mice.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1891-1891
Author(s):  
John T. Piper ◽  
Jaroslav G. Vostal
Keyword(s):  
Animal Model ◽  
Human Platelets ◽  
Human Cells ◽  
Scid Mice ◽  
Survival Times ◽  
Post Infusion ◽  
The Impact ◽  
Induced Aggregation

Abstract Clinical performance of platelet products processed or stored under novel conditions is difficult to predict based on in vitro studies alone. Evaluation of such products involves determination of recovery and survival of radiolabeled platelets in human volunteers as a surrogate endpoint for platelet efficacy. Such human studies pose some risk to volunteers, are a financial burden on the sponsor, and stifle innovation in the development of platelet products. The development of an animal model for evaluating human platelets has been limited by rapid, immunemediated clearance of human cells. In the current studies, severe combined immunodeficient (SCID) mice were used to circumvent the need to block the reticuloendothelial system and prolong circulation of human cells. Human platelets were infused via tail vein into normal and SCID mice, and the recoveries and survival times compared. Mouse whole blood was collected at various time points post-infusion, and human platelets were detected by flow cytometry using an anti-human CD41 monoclonal antibody. Recovery was defined as percent human platelets in circulation relative to time zero, and survival time in circulation as the t1/2 of the human platelets. Recoveries and survival times were different between normal and SCID mice, with a maximal difference in recovery of 60.3% at 4 hours post-infusion (normal recovery, 11.1 ± 9.1%; SCID recovery, 71.4 ± 8.8%), and survival times of 1.4 ± 0.4 hours and 10.7 ± 2.3 hours in normal and SCID mice, respectively (N=3). Chemically treated and aged platelets were used to evaluate the ability of the model to detect differences in control and damaged platelets. Chemical damage was induced by carbonyl cyanide 3-chlorophenylhydrazone (CCCP), a mitochondrial uncoupler which mimics the platelet storage lesion. Platelets were exposed to 10 μM CCCP in methanol, control platelets were exposed to an equal volume of methanol (N=3). CCCP treatment of platelets decreased agonist-induced aggregation (Control aggregation, 73.3 ± 6.8%; CCCP-treated platelet aggregation, 13.8 ± 5.3%). Recovery of control and CCCP-treated platelets were 31.5 ± 16.9% and 7.9 ± 5.1%, respectively, at 4-hours post-infusion. Survival times were 1.3 hours for control and 1.9 hours for CCCP-treated platelets. For storage studies, in vitro cell quality parameters were evaluated in three products, and each product was infused into 3 animals on Day 1 and 3 different animals on Day 7. In Day 7 platelets, in vitro platelet parameters were decreased compared to Day 1. Platelet counts decreased an average of 22.8% ± 2.2% between Day 1 and Day 7. pH decreased from 6.7 ± 0.1 at Day 1 to 5.8 ± 0.1 at Day 7. All platelet products had visible swirl on Day 1 and no swirl on Day 7. Platelets stored for 7 days showed decreased recovery over Day 1 platelets at 4 hours post-infusion (Day 1, 66.9 ± 12.8%; Day 7, 0.2 ± 0.08%). The SCID mouse may be a useful model for evaluating the impact of new technologies (apheresis devices, anticoagulants, storage containers, pathogen inactivation systems) on the in vivo efficacy of human platelets. In two different models of platelet damage (chemical and storage induced damage), this model can distinguish between normal and damaged platelets. Recovery of Infused Day 1 and Day 7 Human Platelets in SCID Mice Recovery of Infused Day 1 and Day 7 Human Platelets in SCID Mice

DNA damage in testicular cells in vitro: The response of rat and human cells to known testicular toxicants

1996 ◽  
Vol 360 (3) ◽  
pp. 287-288
Author(s):  
C. Bjørge ◽  
G. Brunborg ◽  
T. Scholz ◽  
R. Wiger ◽  
J.A. Holme ◽  
...  
Keyword(s):  
Dna Damage ◽  
Human Cells ◽  
Testicular Cells

The impact of in vivo and in vitro exposure to base analogue 5-FU on the level of DNA damage in haemocytes of freshwater mussels Unio pictorum and Unio tumidus

2014 ◽  
Vol 191 ◽  
pp. 145-150 ◽  
Author(s):  
Zoran Gačić ◽  
Stoimir Kolarević ◽  
Karolina Sunjog ◽  
Margareta Kračun-Kolarević ◽  
Momir Paunović ◽  
...  
Keyword(s):  
Dna Damage ◽  
Freshwater Mussels ◽  
In Vitro Exposure ◽  
Unio Tumidus ◽  
The Impact ◽  
Unio Pictorum

scholarly journals Genotoxicity of Marijuana in Mono-Users

2021 ◽  
Vol 12 ◽  
Author(s):  
Eunice Fabian-Morales ◽  
Carmen Fernández-Cáceres ◽  
Adriana Gudiño ◽  
Marco A. Andonegui Elguera ◽  
Karla Torres-Arciga ◽  
...  
Keyword(s):  
Dna Damage ◽  
Illicit Drugs ◽  
Nuclear Division ◽  
Peripheral Blood Lymphocytes ◽  
Control Group ◽  
Chromosomal Damage ◽  
Chromosomal Dna ◽  
Genotoxic Effects ◽  
Nuclear Division Index ◽  
Definition Of

Marijuana (Cannabis sp.) is among the most recurred controlled substances in the world, and there is a growing tendency to legalize its possession and use; however, the genotoxic effects of marijuana remain under debate. A clear definition of marijuana's genotoxic effects remains obscure by the simultaneous consumption of tobacco and other recreational substances. In order to assess the genotoxic effects of marijuana and to prevent the bias caused by the use of substances other than cannabis, we recruited marijuana users that were sub-divided into three categories: (1) users of marijuana-only (M), (2) users of marijuana and tobacco (M+T), and (3) users of marijuana plus other recreative substances or illicit drugs (M+O), all the groups were compared against a non-user control group. We quantified DNA damage by detection of γH2AX levels and quantification of micronuclei (MN), one of the best-established methods for measuring chromosomal DNA damage. We found increased levels of γH2AX in peripheral blood lymphocytes from the M and M+T groups, and increased levels of MNs in cultures from M+T group. Our results suggest a DNA damage increment for M and M+T groups but the extent of chromosomal damage (revealed here by the presence of MNs and NBuds) might be related to the compounds found in tobacco. We also observed an elevated nuclear division index in all marijuana users in comparison to the control group suggesting a cytostatic dysregulation caused by cannabis use. Our study is the first in Mexico to assess the genotoxicity of marijuana in mono-users and in combination with other illicit drugs.

scholarly journals PARP inhibition in Ewing sarcoma: impact of germline DNA damage repair defects and activation of immunoregulatory pathways

2020 ◽  
Author(s):  
Lisa M. Maurer ◽  
Rosemarie E. Venier ◽  
Elina Mukherjee ◽  
Claire M. Julian ◽  
Jessica D. Daley ◽  
...  
Keyword(s):  
Dna Damage ◽  
Ewing Sarcoma ◽  
Immune Checkpoint ◽  
Dna Damage Repair ◽  
Germline Mutations ◽  
Parp Inhibition ◽  
Damage Repair ◽  
The Impact ◽  
Ewing Tumor

ABSTRACTEwing sarcoma, an oncofusion-driven primary bone tumor, can occur in the setting of various germline mutations in DNA damage repair pathway genes. We recently reported our discovery of a germline mutation in the DNA damage repair protein BARD1 (BRCA1-associated RING domain-1) in a patient with Ewing sarcoma. BARD1 is recruited to the site of DNA double stranded breaks via the poly(ADP-ribose) polymerase (PARP) protein and plays a critical role in DNA damage response pathways including homologous recombination. PARP inhibitors (PARPi) are effective against Ewing sarcoma cells in vitro, though have demonstrated limited success in clinical trials to date. In order to assess the impact of BARD1 loss on Ewing sarcoma sensitivity to PARP inhibitor therapy, we generated the novel PSaRC318 patient-derived Ewing tumor cell from our patient with a germline BARD1 mutation and then analyzed the response of these cells to PARPi. We demonstrate that PSaRC318 cells are sensitive to PARP inhibition and by testing the effect of BARD1 depletion in additional Ewing sarcoma cell lines, we confirm that loss of BARD1 enhances PARPi sensitivity. In certain malignancies, DNA damage can activate the IRF1 (interferon response factor 1) immunoregulatory pathway, and the activation of this pathway can drive immunosuppression through upregulation of the immune checkpoint protein PD-L1. In order to determine the ability of PARPi to alter Ewing tumor immunoregulation, we evaluated whether PARPi results in upregulation of the IRF1-PDL1 pathway. Indeed, we now demonstrate that PARPi leads to increased PD-L1 expression in Ewing sarcoma. Together, these data thus far suggest that while Ewing tumors harboring germline mutations in DNA damage repair proteins may in respond to PARPi in vitro, in vivo benefit of PARPi may only be demonstrated when counteracting the immunosuppressive effects of DNA damage by concurrently targeting immune checkpoint proteins.

scholarly journals Duplex-Repair enables highly accurate sequencing, despite DNA damage

2021 ◽  
Author(s):  
Kan Xiong ◽  
Douglas Shea ◽  
Justin Rhoades ◽  
Timothy Blewett ◽  
Ruolin Liu ◽  
...  
Keyword(s):  
Dna Damage ◽  
High Accuracy ◽  
Base Pairs ◽  
Free Dna ◽  
Duplex Sequencing ◽  
Tumor Biopsies ◽  
The Impact ◽  
Formalin Fixed ◽  
Fixed Tumor

Abstract Accurate DNA sequencing is crucial in biomedicine. Underlying the most accurate methods is the assumption that a mutation is true if altered bases are present on both strands of the DNA duplex. We now show that this assumption can be wrong. We establish that current methods to prepare DNA for sequencing, via ‘End Repair/dA-Tailing,’ may substantially resynthesize strands, leading amplifiable lesions or alterations on one strand to become indiscernible from true mutations on both strands. Indeed, we discovered that 7–17% and 32–57% of interior ‘duplex base pairs’ from cell-free DNA and formalin-fixed tumor biopsies, respectively, could be resynthesized in vitro and potentially introduce false mutations. To address this, we present Duplex-Repair, and show that it limits interior duplex base pair resynthesis by 8- to 464-fold, rescues the impact of induced DNA damage, and affords up to 8.9-fold more accurate duplex sequencing. Our study uncovers a major Achilles’ heel in sequencing and offers a solution to restore high accuracy.

Induction of the DNA damage response by IAP inhibition triggers natural immunity via upregulation of NKG2D ligands in Hodgkin lymphoma in vitro

2013 ◽  
Vol 394 (10) ◽  
pp. 1325-1331 ◽  
Author(s):  
Maike Sauer ◽  
Katrin S. Reiners ◽  
Hinrich P. Hansen ◽  
Andreas Engert ◽  
Stephan Gasser ◽  
...  
Keyword(s):  
Dna Damage ◽  
Hodgkin Lymphoma ◽  
Dna Damage Response ◽  
Natural Immunity ◽  
Immune Recognition ◽  
Iap Antagonist ◽  
Damage Response ◽  
The Impact ◽  
Apoptosis Proteins

Abstract Evasion of apoptosis is a hallmark of cancer cells. Inhibitor of apoptosis proteins (IAPs) act as endogenous inhibitors of programmed cell death and are overexpressed in several tumors including Hodgkin lymphoma (HL). Preclinical studies indicate antitumor activity of IAP antagonists and clinical studies in hematological malignancies are underway. Here, we investigate the impact of the small molecule IAP antagonist LCL161 on HL cell lines. Although the antagonist caused rapid degradation of cIAP1 leading to TNFα secretion, LCL161 did not promote apoptosis significantly. However, LCL161 induced expression of MICA and MICB, ligands for the activating immune receptor NKG2D, and enhanced the susceptibility of HL cells to NKG2D-dependent lysis by NK cells. MICA/B upregulation was dependent on activation of the DNA damage response upon LCL161 treatment. Taken together, we demonstrate a novel link between IAP inhibition, DNA damage and immune recognition.

Monitoring DNA-Ligand Interactions in Living Human Cells Using High-Resolution NMR Spectroscopy

2019 ◽  
Author(s):  
Michaela Krafcikova ◽  
Simon Dzatko ◽  
Coralie Caron ◽  
Anton Granzhan ◽  
Radovan Fiala ◽  
...  
Keyword(s):  
High Resolution ◽  
Human Cells ◽  
Ligand Complex ◽  
Direct Evaluation ◽  
Intracellular Environment ◽  
Cellular Environment ◽  
High Resolution Nmr ◽  
Ligand Interactions ◽  
The Impact

High-resolution studies of DNA–ligand interactions in the cellular environment are problematic due to the lack of suitable biophysical tools. To address this issue, we developed an in-cell NMR-based approach for monitoring DNA–ligand interactions inside the nuclei of living human cells. Our method relies on the acquisition of high-resolution NMR data of cells electroporated with pre-formed DNA-ligand complex. The impact of the intracellular environment on the integrity of the complex is assessed on the basis of in-cell NMR signals from unbound and ligand-bound forms of a given DNA target. By using this technique, we studied complexes of model DNA fragments and four ligands, representative of DNA minor-groove binders (netropsin) or ligands binding to DNA pairing defects (naphthalenophanes). We demonstrate that some of the <i>in vitro</i> validated ligands retain their ability to form stable on-target DNA interactions <i>in situ</i>, while other<i> </i>lose this ability due to off-target interactions with genomic DNA as well as cellular metabolic components. Collectively, our data suggest that direct evaluation of behavior of drug-like molecules in the intracellular environment provides important insights for the design and development of DNA-binding ligands with the desired biological action and minimal side effects resulting from off-target binding.<br><div><br></div>

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