LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 73

Search options

  1. Article ; Online: Pluripotent stem cells for target organ developmental toxicity testing.

    Wu, Xian / Chen, Yichang / Kreutz, Anna / Silver, Brian / Tokar, Erik J

    Toxicological sciences : an official journal of the Society of Toxicology

    2024  

    Abstract: Prenatal developmental toxicity research focuses on understanding potential adverse effects of environmental agents, drugs, and chemicals on the development of embryos and fetuses. Traditional methods involve animal testing, but ethical concerns and the ... ...

    Abstract Prenatal developmental toxicity research focuses on understanding potential adverse effects of environmental agents, drugs, and chemicals on the development of embryos and fetuses. Traditional methods involve animal testing, but ethical concerns and the need for human-relevant models have prompted the exploration of alternatives. Pluripotent stem cells (PSCs) are versatile cells with the unique ability to differentiate into any cell type, serving as a foundational tool for studying human development. Two-dimensional (2D) PSC models are often chosen for their ease of use and reproducibility for high-throughput screening. However, they lack the complexity of an in vivo environment. Alternatively, three-dimensional (3D) PSC models, such as organoids, offer tissue architecture and intercellular communication more reminiscent of in vivo conditions. However, they are complicated to produce and analyze, usually requiring advanced and expensive techniques. This review discusses recent advances in the use of human PSCs differentiated into brain and heart lineages and emerging tools and methods that can be combined with PSCs to help address important scientific questions in the area developmental toxicology. These advancements and new approach methods align with the push for more relevant and predictive developmental toxicity assessment, combining innovative techniques with organoid models to advance regulatory decision-making.
    Language English
    Publishing date 2024-03-28
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1420885-4
    ISSN 1096-0929 ; 1096-6080
    ISSN (online) 1096-0929
    ISSN 1096-6080
    DOI 10.1093/toxsci/kfae037
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: Molecular Mechanisms of Cytotoxicity of NCX4040, the Non-Steroidal Anti-Inflammatory NO-Donor, in Human Ovarian Cancer Cells.

    Sinha, Birandra K / Tokar, Erik J / Bortner, Carl D

    International journal of molecular sciences

    2022  Volume 23, Issue 15

    Abstract: NCX4040, the non-steroidal anti-inflammatory-NO donor, is cytotoxic to several human tumors, including ovarian tumor cells. We have found that NCX4040 is also cytotoxic against both OVCAR-8 and its adriamycin resistant (NCI/ADR-RES) tumor cell lines. ... ...

    Abstract NCX4040, the non-steroidal anti-inflammatory-NO donor, is cytotoxic to several human tumors, including ovarian tumor cells. We have found that NCX4040 is also cytotoxic against both OVCAR-8 and its adriamycin resistant (NCI/ADR-RES) tumor cell lines. Here, we have examined mechanism(s) for the cytotoxicity of NCX4040 in OVCAR-8 and NCI/ADR-RES cell lines. We found that NCX4040 induced significant apoptosis in both cell lines. Furthermore, NCX4040 treatment caused significant depletion of cellular glutathione, causing oxidative stress due to the formation of reactive oxygen/nitrogen species (ROS/RNS). Significantly more ROS/RNS were detected in OVCAR-8 cells than in NCI/ADR-RES cells which may have resulted from increased activities of SOD, glutathione peroxidase and transferases expressed in NCI/ADR-RES cells. NCX4040 treatment resulted in the formation of double-strand DNA breaks in both cells; however, more of these DNA breaks were detected in OVCAR-8 cells. RT-PCR studies indicated that NCX4040-induced DNA damage was not repaired as efficiently in NCI/ADR-RES cells as in OVCAR-8 cells which may lead to a differential cell death. Pretreatment of OVCAR-8 cells with N-acetylcysteine (NAC) significantly decreased cytotoxicity of NCX4040 in OVCAR-8 cells; however, NAC had no effects on NCX4040 cytotoxicity in NCI/ADR-RES cells. In contrast, FeTPPS, a peroxynitrite scavenger, completely blocked NCX4040-induced cell death in both cells, suggesting that NCX4040-induced cell death could be mediated by peroxynitrite formed from NCX4040 following cellular metabolism.
    MeSH term(s) Anti-Inflammatory Agents, Non-Steroidal/therapeutic use ; Antineoplastic Agents/pharmacology ; Aspirin/analogs & derivatives ; Carcinoma, Ovarian Epithelial ; Doxorubicin/pharmacology ; Female ; Humans ; Nitro Compounds ; Ovarian Neoplasms/pathology ; Peroxynitrous Acid ; Reactive Nitrogen Species ; Reactive Oxygen Species
    Chemical Substances Anti-Inflammatory Agents, Non-Steroidal ; Antineoplastic Agents ; NCX 4040 ; Nitro Compounds ; Reactive Nitrogen Species ; Reactive Oxygen Species ; Peroxynitrous Acid (14691-52-2) ; Doxorubicin (80168379AG) ; Aspirin (R16CO5Y76E)
    Language English
    Publishing date 2022-08-03
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2019364-6
    ISSN 1422-0067 ; 1422-0067 ; 1661-6596
    ISSN (online) 1422-0067
    ISSN 1422-0067 ; 1661-6596
    DOI 10.3390/ijms23158611
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: MicroRNAs: small molecules with big effects.

    Tokar, Erik J

    Toxicology and applied pharmacology

    2016  Volume 312, Page(s) 1–2

    MeSH term(s) Animals ; Biomarkers/metabolism ; Humans ; MicroRNAs/biosynthesis ; MicroRNAs/genetics ; Neoplasms/genetics ; Neoplasms/metabolism
    Chemical Substances Biomarkers ; MicroRNAs
    Language English
    Publishing date 2016--01
    Publishing country United States
    Document type Editorial
    ZDB-ID 204477-8
    ISSN 1096-0333 ; 0041-008X
    ISSN (online) 1096-0333
    ISSN 0041-008X
    DOI 10.1016/j.taap.2016.11.004
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article ; Online: Stem Cells as Target for Prostate cancer Therapy: Opportunities and Challenges.

    Escudero-Lourdes, Claudia / Alvarado-Morales, Ildemar / Tokar, Erik J

    Stem cell reviews and reports

    2022  Volume 18, Issue 8, Page(s) 2833–2851

    Abstract: Cancer stem cells (CSCs) and cells in a cancer stem cell-like (CSCL) state have proven to be responsible for tumor initiation, growth, and relapse in Prostate Cancer (PCa) and other cancers; therefore, new strategies are being developed to target such ... ...

    Abstract Cancer stem cells (CSCs) and cells in a cancer stem cell-like (CSCL) state have proven to be responsible for tumor initiation, growth, and relapse in Prostate Cancer (PCa) and other cancers; therefore, new strategies are being developed to target such cellular populations. TLR3 activation-based immunotherapy using Polyinosinic:Polycytidylic acid (PIC) has been proposed to be used as a concomitant strategy to first-line treatment. This strategy is based on the induction of apoptosis and an inflammatory response in tumor cells. In combination with retinoids like 9cRA, this treatment can induce CSCs differentiation and apoptosis. A limitation in the use of this combination is the common decreased expression of TLR3 and its main positive regulator p53. observed in many patients suffering of different cancer types such as PCa. Importantly, human exposure to certain toxicants, such as iAs, not only has proven to enrich CSCs population in an in vitro model of human epithelial prostate cells, but additionally, it can also lead to a decreased p53, TLR3 and RA receptor (RARβ), expression/activation and thus hinder this treatment efficacy. Therefore, here we point out the relevance of evaluating the TLR3 and P53 status in PCa patients before starting an immunotherapy based on the use of PIC +9cRA to determine whether they will be responsive to treatment. Additionally, the use of strategies to overcome the lower TLR3, RARβ or p53 expression in PCa patients, like the inclusion of drugs that increase p53 expression, is encouraged, to potentiate the use of PIC+RA based immunotherapy in these patients.
    MeSH term(s) Male ; Humans ; Prostate/metabolism ; Prostate/pathology ; Toll-Like Receptor 3/metabolism ; Tumor Suppressor Protein p53/genetics ; Neoplasm Recurrence, Local ; Prostatic Neoplasms/therapy ; Prostatic Neoplasms/drug therapy ; Stem Cells/metabolism
    Chemical Substances Toll-Like Receptor 3 ; Tumor Suppressor Protein p53
    Language English
    Publishing date 2022-08-11
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 2495577-2
    ISSN 2629-3277 ; 1558-6804 ; 1550-8943
    ISSN (online) 2629-3277 ; 1558-6804
    ISSN 1550-8943
    DOI 10.1007/s12015-022-10437-6
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: Arsenic as an environmental toxicant and a therapeutic agent: Foe and friend.

    Xu, Yuanyuan / Tokar, Erik J / Pi, Jingbo

    Toxicology and applied pharmacology

    2021  Volume 415, Page(s) 115438

    MeSH term(s) Animals ; Antineoplastic Agents/adverse effects ; Arsenic/adverse effects ; Arsenic Poisoning/etiology ; Arsenic Poisoning/genetics ; Arsenic Poisoning/metabolism ; Arsenic Poisoning/pathology ; Cell Transformation, Neoplastic/chemically induced ; Cell Transformation, Neoplastic/genetics ; Cell Transformation, Neoplastic/metabolism ; Cell Transformation, Neoplastic/pathology ; DNA Damage ; Epigenesis, Genetic/drug effects ; Gene Expression Regulation, Neoplastic ; Humans ; Neoplasms/chemically induced ; Neoplasms/genetics ; Neoplasms/metabolism ; Neoplasms/pathology ; Nervous System/drug effects ; Nervous System/metabolism ; Nervous System/pathology ; Patient Safety ; Risk Assessment ; Risk Factors
    Chemical Substances Antineoplastic Agents ; Arsenic (N712M78A8G)
    Language English
    Publishing date 2021-02-04
    Publishing country United States
    Document type Editorial ; Introductory Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 204477-8
    ISSN 1096-0333 ; 0041-008X
    ISSN (online) 1096-0333
    ISSN 0041-008X
    DOI 10.1016/j.taap.2021.115438
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article ; Online: Pluripotent Stem Cells in Developmental Toxicity Testing: A Review of Methodological Advances.

    Luz, Anthony L / Tokar, Erik J

    Toxicological sciences : an official journal of the Society of Toxicology

    2018  Volume 165, Issue 1, Page(s) 31–39

    Abstract: Millions of children are born each year with a birth defect. Many of these defects are caused by environmental factors, although the underlying etiology is often unknown. In vivo mammalian models are frequently used to determine if a chemical poses a ... ...

    Abstract Millions of children are born each year with a birth defect. Many of these defects are caused by environmental factors, although the underlying etiology is often unknown. In vivo mammalian models are frequently used to determine if a chemical poses a risk to the developing fetus. However, there are over 80 000 chemicals registered for use in the United States, many of which have undergone little safety testing, necessitating the need for higher-throughput methods to assess developmental toxicity. Pluripotent stem cells (PSCs) are an ideal in vitro model to investigate developmental toxicity as they possess the capacity to differentiate into nearly any cell type in the human body. Indeed, a burst of research has occurred in the field of stem cell toxicology over the past decade, which has resulted in numerous methodological advances that utilize both mouse and human PSCs, as well as cutting-edge technology in the fields of metabolomics, transcriptomics, transgenics, and high-throughput imaging. Here, we review the wide array of approaches used to detect developmental toxicants, suggest areas for further research, and highlight critical aspects of stem cell biology that should be considered when utilizing PSCs in developmental toxicity testing.
    MeSH term(s) Animal Testing Alternatives ; Animals ; Cell Culture Techniques ; Cell Differentiation/drug effects ; Cell Survival/drug effects ; Embryonic Development/drug effects ; Embryonic Stem Cells/drug effects ; Embryonic Stem Cells/pathology ; Humans ; Induced Pluripotent Stem Cells/drug effects ; Induced Pluripotent Stem Cells/pathology ; Models, Biological ; Myocytes, Cardiac/drug effects ; Myocytes, Cardiac/pathology ; Toxicity Tests/methods
    Language English
    Publishing date 2018-08-31
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Review
    ZDB-ID 1420885-4
    ISSN 1096-0929 ; 1096-6080
    ISSN (online) 1096-0929
    ISSN 1096-6080
    DOI 10.1093/toxsci/kfy174
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article: Elucidation of Mechanisms of Topotecan-Induced Cell Death in Human Breast MCF-7 Cancer Cells by Gene Expression Analysis.

    Sinha, Birandra K / Tokar, Erik J / Bushel, Pierre R

    Frontiers in genetics

    2020  Volume 11, Page(s) 775

    Abstract: Topotecan is a clinically active anticancer agent for the management of various human tumors. While the principal mechanism of tumor cell killing by topotecan is due to its interactions with topoisomerase I and formation of DNA double-strand breaks, ... ...

    Abstract Topotecan is a clinically active anticancer agent for the management of various human tumors. While the principal mechanism of tumor cell killing by topotecan is due to its interactions with topoisomerase I and formation of DNA double-strand breaks, recent studies suggest that mechanisms involving generation of reactive free radicals and induction of oxidative stress may play a significant role in topotecan-dependent tumor cell death. We have shown that topotecan generates a topotecan radical following one-electron oxidation by a peroxidase-hydrogen peroxide system which reacts with reduced glutathione and cysteine, forming the glutathiyl and cysteinyl radicals, respectively. While little is known how these events are involved in topotecan-induced tumor cell death, we have now examined the effects of topotecan short (1 h) and long (24 h) exposure on global gene expression patterns using gene expression microarray analysis in human breast MCF-7 cancer cells, a wild-type p53 containing cell line. We show here that topotecan treatment significantly down-regulated estrogen receptor alpha (ERα/ESR1) and antiapoptotic BCL2 genes in addition to many other p53-regulated genes. Furthermore, 8-oxoguanine DNA glycosylase (OGG1), ferredoxin reductase (FDXR), methionine sulfoxide reductase (MSR), glutathione peroxidases (GPx), and glutathione reductase (GSR) genes were also differentially expressed by topotecan treatment. The differential expression of these genes was observed in a wild-type p53-containing breast ZR-75-1 tumor cell line following topotecan treatment. The involvement of reactive oxygen free radical sensor genes, the oxidative DNA damage (OGG1) repair gene and induction of pro-apoptotic genes suggest that reactive free radical species play a role in topotecan-induced tumor cell death.
    Language English
    Publishing date 2020-07-17
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2606823-0
    ISSN 1664-8021
    ISSN 1664-8021
    DOI 10.3389/fgene.2020.00775
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article ; Online: Cardiac Development in the Presence of Cadmium: An

    Wu, Xian / Chen, Yichang / Luz, Anthony / Hu, Guang / Tokar, Erik J

    Environmental health perspectives

    2022  Volume 130, Issue 11, Page(s) 117002

    Abstract: Background: Exposure to cadmium (Cd) is associated with cardiovascular diseases. Maternal Cd exposure is a significant risk factor for congenital heart disease. However, mechanisms of Cd on developmental cardiotoxicity are not well defined.: ... ...

    Abstract Background: Exposure to cadmium (Cd) is associated with cardiovascular diseases. Maternal Cd exposure is a significant risk factor for congenital heart disease. However, mechanisms of Cd on developmental cardiotoxicity are not well defined.
    Objectives: We evaluated the effects of Cd on the different stages (mesoderm, cardiac induction, cardiac function) of cardiac development using an early embryo development
    Methods: Embryonic stem cells (ESCs) form 3D aggregates, called embryoid bodies, that recapitulate events involved with early embryogenesis (e.g., germ layer formation). This model was used for early germ layer formation and signaling pathway identification. The 2D cardiomyocyte differentiation from the
    Results: Cd (
    Discussion: In conclusion, using a human ESC-derived 2D/3D
    MeSH term(s) Humans ; Human Embryonic Stem Cells ; Cadmium/toxicity ; Cadmium/metabolism ; Organoids ; Cell Differentiation ; Myocytes, Cardiac/metabolism ; Transcription Factors/metabolism
    Chemical Substances Cadmium (00BH33GNGH) ; Transcription Factors
    Language English
    Publishing date 2022-11-02
    Publishing country United States
    Document type Journal Article
    ZDB-ID 195189-0
    ISSN 1552-9924 ; 0091-6765 ; 1078-0475
    ISSN (online) 1552-9924
    ISSN 0091-6765 ; 1078-0475
    DOI 10.1289/EHP11208
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article ; Online: Ferroptosis-Mediated Cell Death Induced by NCX4040, The Non-Steroidal Nitric Oxide Donor, in Human Colorectal Cancer Cells: Implications in Therapy.

    Sinha, Birandra K / Bortner, Carl D / Jarmusch, Alan K / Tokar, Erik J / Murphy, Carri / Wu, Xian / Winter, Heather / Cannon, Ronald E

    Cells

    2023  Volume 12, Issue 12

    Abstract: Our recent studies show that the treatment of human ovarian tumor cells with NCX4040 results in significant depletions of cellular glutathione, the formation of reactive oxygen/nitrogen species and cell death. NCX4040 is also cytotoxic to several human ... ...

    Abstract Our recent studies show that the treatment of human ovarian tumor cells with NCX4040 results in significant depletions of cellular glutathione, the formation of reactive oxygen/nitrogen species and cell death. NCX4040 is also cytotoxic to several human colorectal cancer (CRC) cells in vitro and in vivo. Here, we examined the ferroptosis-dependent mechanism(s) of cytotoxicity of NCX4040 in HT-29 and K-RAS mutant HCT 116 colon cell lines. Ferroptosis is characterized by the accumulation of reactive oxygen species (ROS) within the cell, leading to an iron-dependent oxidative stress-mediated cell death. However, its relevance in the mechanism of NCX4040 cytotoxicity in CRCs is not known. We found that NCX4040 generates ROS in CRC cells without any depletion of cellular GSH. Combinations of NCX4040 with erastin (ER) or RSL3 (RAS-selective lethal 3), known inducers of ferroptosis, enhanced CRC death. In contrast, ferrostatin-1, an inhibitor of ferroptosis, significantly inhibited NCX4040-induced cell death. Treatment of CRC cells with NCX4040 resulted in the induction of lipid peroxidation in a dose- and time-dependent manner. NCX4040 treatment induced several genes related to ferroptosis (e.g., CHAC1, GPX4 and NOX4) in both cell lines. Metabolomic studies also indicated significant increases in both lipid and energy metabolism following the drug treatment in HT-29 and HCT 116 cells. These observations strongly suggest that NCX4040 causes the ferroptosis-mediated cell death of CRC cells. Furthermore, combinations of NCX4040 and ER or RSL3 may contribute significantly to the treatment of CRC, including those that are difficult to treat due to the presence of Ras mutations in the clinic. NCX4040-induced ferroptosis may also be a dynamic form of cell death for the treatment of other cancers.
    MeSH term(s) Humans ; Nitric Oxide Donors/pharmacology ; Ferroptosis ; Reactive Oxygen Species/metabolism ; Carbolines/pharmacology ; Cell Death ; Glutathione/metabolism ; Colorectal Neoplasms/drug therapy
    Chemical Substances NCX 4040 ; Nitric Oxide Donors ; Reactive Oxygen Species ; Carbolines ; Glutathione (GAN16C9B8O)
    Language English
    Publishing date 2023-06-14
    Publishing country Switzerland
    Document type Journal Article ; Research Support, N.I.H., Intramural
    ZDB-ID 2661518-6
    ISSN 2073-4409 ; 2073-4409
    ISSN (online) 2073-4409
    ISSN 2073-4409
    DOI 10.3390/cells12121626
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  10. Article ; Online: Cadmium Exposure and Ovarian Reserve in Women Aged 35-49 Years: The Impact on Results From the Creatinine Adjustment Approach Used to Correct for Urinary Dilution.

    Upson, Kristen / O'Brien, Katie M / Hall, Janet E / Tokar, Erik J / Baird, Donna D

    American journal of epidemiology

    2020  Volume 190, Issue 1, Page(s) 116–124

    Abstract: Cadmium is toxic to the ovaries in animal studies, but its association with diminished ovarian reserve in women is not established. We investigated urinary cadmium, a biomarker of long-term exposure, in relation to diminished ovarian reserve, as ... ...

    Abstract Cadmium is toxic to the ovaries in animal studies, but its association with diminished ovarian reserve in women is not established. We investigated urinary cadmium, a biomarker of long-term exposure, in relation to diminished ovarian reserve, as indicated by elevated serum follicle-stimulating hormone concentrations (≥10 IU/L), in women aged 35-49 years (unweighted n = 1,681). Using data from the Third National Health and Nutrition Examination Survey (1988-1994), we conducted Poisson regression to estimate adjusted relative risks and 95% confidence intervals. Because the best approach to correcting for urinary dilution in spot samples with creatinine remains controversial, we employed 3 approaches: standardization, covariate adjustment, and covariate-adjusted standardization. Our data suggested a modest association with standardization (highest quartile vs. lowest: relative risk (RR) = 1.3, 95% confidence interval (CI): 0.8, 1.9; P for trend = 0.06) and covariate-adjusted standardization (highest quartile vs. lowest: RR = 1.3, 95% CI: 0.9, 1.9; P for trend = 0.05) and a stronger association with covariate adjustment (highest quartile vs. lowest: RR = 1.8, 95% CI: 1.2, 2.9; P for trend = 0.01). The stronger association with covariate adjustment may reflect bias from conditioning on urinary creatinine, a collider in the hypothesized causal pathway. We conclude that cadmium may contribute to ovarian aging in women and that careful consideration of the creatinine adjustment approach is needed to minimize bias.
    MeSH term(s) Adult ; Biomarkers/blood ; Biomarkers/urine ; Cadmium/urine ; Creatinine/urine ; Environmental Exposure ; Female ; Follicle Stimulating Hormone/blood ; Humans ; Middle Aged ; Nutrition Surveys ; Ovarian Reserve ; United States ; Urinalysis
    Chemical Substances Biomarkers ; Cadmium (00BH33GNGH) ; Follicle Stimulating Hormone (9002-68-0) ; Creatinine (AYI8EX34EU)
    Language English
    Publishing date 2020-04-03
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, N.I.H., Intramural
    ZDB-ID 2937-3
    ISSN 1476-6256 ; 0002-9262
    ISSN (online) 1476-6256
    ISSN 0002-9262
    DOI 10.1093/aje/kwaa037
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top