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1.
Nutr Cancer ; 76(6): 463-468, 2024.
Article in English | MEDLINE | ID: mdl-38591931

ABSTRACT

Methionine is an essential amino acid critical for cell growth and survival. Preclinical evidence suggests a methionine restricted diet (MRD) sensitizes cancer to radiation therapy (RT), without significant adverse effects. However, this has never been evaluated in humans. The purpose of this pilot study was to evaluate the safety and feasibility of concurrent MRD with standard-of-care definitive RT in adults with any non-skin cancer malignancy. The MRD extended from 2 wk before RT initiation, through 2 wk beyond RT completion. The primary endpoint of safety was assessed as rate of grade 3 or higher acute and late toxicities. Feasibility was assessed with quantitative plasma amino acid panel every 2 wk during the MRD (target plasma methionine 13 µM). Nine patients were accrued over a two-year period, with five able to complete the treatment course. The trial was closed due to slow accrual and subjects' difficulty maintaining the diet. No grade 3 or higher adverse events were observed. Subjects' average methionine level was 18.8 µM during treatment, with average nadir 16.8 µM. These findings suggest the safety of concurrent MRD with RT, with toxicities comparable to those expected with RT alone. However, the diet was challenging, and unacceptable to most patients.


Subject(s)
Methionine , Humans , Methionine/blood , Male , Middle Aged , Female , Pilot Projects , Aged , Adult , Neoplasms/radiotherapy , Neoplasms/diet therapy , Diet
2.
Regul Toxicol Pharmacol ; 153: 105708, 2024 Nov.
Article in English | MEDLINE | ID: mdl-39304112

ABSTRACT

Botanical supplements and herbal products are widely used by consumers for various purported health benefits, and their popularity is increasing. Some of these natural products can have adverse effects on liver function and/or interact with prescription and over-the-counter (OTC) medications. Ensuring the safety of these readily available products is a crucial public health concern; however, not all regulatory authorities require premarket safety review and/or testing. To address and discuss these and other emerging needs related to botanical safety, a symposium was held at the Society of Toxicology Annual Meeting in Salt Lake City (UT) on March 11, 2024. The symposium addressed the latest research on botanical-induced liver toxicity and botanical-drug interactions, including new approach methods to screen for toxicity, challenges in assessing the safety of botanicals, and relating human adverse events to specific products. The presentations and robust panel discussion between the speakers and audience highlighted the need for further research and collaboration to improve the safety of botanical supplements and herbal products, with the ultimate goal of protecting consumer health. Although utility of many of the modern tools presented in the symposium requires further study, the synergistic efforts of diverse experts hold promise for effective prediction and evaluation of botanical-induced hepatotoxicity and botanical-drug interaction potential.


Subject(s)
Chemical and Drug Induced Liver Injury , Dietary Supplements , Herb-Drug Interactions , Plant Preparations , Humans , Chemical and Drug Induced Liver Injury/etiology , Animals , Plant Preparations/adverse effects , Plant Preparations/toxicity
3.
Drug Chem Toxicol ; : 1-8, 2024 Aug 19.
Article in English | MEDLINE | ID: mdl-39155655

ABSTRACT

Cannabidiol (CBD) is a major phytocannabinoid from Cannabis sativa. It is currently widely available and widely used in the USA, but despite its rapid progress to market, the pharmacology and toxicology of both CBD and cannabidiol-rich cannabis extracts (CRCE) remain largely unknown. The goals of this study were to investigate the potential of a novel human microphysiological system to emulate CRCE-induced hepatotoxicity and pharmacological properties demonstrated in animal models. For this purpose, C57BL6/J male mice were subjected to dosing with either 0, 61.5, 184.5, or 615 mg/kg of CRCE for 10 days. The liver-on-chip system, incorporating human primary hepatocytes, sinusoidal endothelial cells, as well as Kupffer and stellate cells was subjected to 0, 300, 1,200, or 4,400 ng/mL of CRCE (8 h exposure followed by 16 h washout) for 5 days. Administration of CRCE in mice resulted in nearly 4-fold elevations of plasma ALT at 615 mg/kg (p < 0.01) and a dose-dependent decrease in intrahepatic miR-122. Elevated levels of ALT, paralleled by decreased intrahepatic and increased effluent levels of miR-122, were also observed in the liver-on-chip, although these results were not statistically significant. Exposure to CRCE resulted in a robust and dose-dependent induction of key cytochrome P450 enzymes, namely Cyp1a2, Cyp2b6 (CYP2B10), Cyp2e1, and Cyp2c9 (CYP2C19) in both mouse livers and liver-on-chip. The results of this study demonstrate the congruence between the responses observed in mouse and human liver-on-chip experimental systems and provide evidence of the potential microphysiological systems hold for translating animal data into clinical practice.

4.
Int J Mol Sci ; 25(2)2024 Jan 13.
Article in English | MEDLINE | ID: mdl-38256089

ABSTRACT

Astronauts in space are subject to continuous exposure to ionizing radiation. There is concern about the acute and late-occurring adverse health effects that astronauts could incur following a protracted exposure to the space radiation environment. Therefore, it is vital to consider the current tools and models used to describe and study the organic consequences of ionizing radiation exposure. It is equally important to see where these models could be improved. Historically, radiobiological models focused on how radiation damages nuclear deoxyribonucleic acid (DNA) and the role DNA repair mechanisms play in resulting biological effects, building on the hypotheses of Crowther and Lea from the 1940s and 1960s, and they neglected other subcellular targets outside of nuclear DNA. The development of these models and the current state of knowledge about radiation effects impacting astronauts in orbit, as well as how the radiation environment and cellular microenvironment are incorporated into these radiobiological models, aid our understanding of the influence space travel may have on astronaut health. It is vital to consider the current tools and models used to describe the organic consequences of ionizing radiation exposure and identify where they can be further improved.


Subject(s)
Drug-Related Side Effects and Adverse Reactions , Radiation Exposure , Radiation Injuries , Humans , Astronauts , Cellular Microenvironment , DNA
5.
Int J Mol Sci ; 22(5)2021 Feb 27.
Article in English | MEDLINE | ID: mdl-33673497

ABSTRACT

Both cell and animal studies have shown that complete or partial deficiency of methionine inhibits tumor growth. Consequently, the potential implementation of this nutritional intervention has recently been of great interest for the treatment of cancer patients. Unfortunately, diet alteration can also affect healthy immune cells such as monocytes/macrophages and their precursor cells in bone marrow. As around half of cancer patients are treated with radiotherapy, the potential deleterious effect of dietary methionine deficiency on immune cells prior to and/or following irradiation needs to be evaluated. Therefore, we examined whether modulation of methionine content alters genetic stability in the murine RAW 264.7 monocyte/macrophage cell line in vitro by chromosomal analysis after 1-month culture in a methionine-deficient or supplemented medium. We also analyzed chromosomal aberrations in the bone marrow cells of CBA/J mice fed with methionine-deficient or supplemented diet for 2 months. While all RAW 264.7 cells revealed a complex translocation involving three chromosomes, three different clones based on the banding pattern of chromosome 9 were identified. Methionine deficiency altered the ratio of the three clones and increased chromosomal aberrations and DNA damage in RAW 264.7. Methionine deficiency also increased radiation-induced chromosomal aberration and DNA damage in RAW 264.7 cells. Furthermore, mice maintained on a methionine-deficient diet showed more chromosomal aberrations in bone marrow cells than those given methionine-adequate or supplemented diets. These findings suggest that caution is warranted for clinical implementation of methionine-deficient diet concurrent with conventional cancer therapy.


Subject(s)
Bone Marrow Cells/metabolism , Chromosome Aberrations , DNA Damage , Malnutrition/genetics , Methionine/deficiency , Animals , DNA Repair , Diet , Macrophages , Male , Malnutrition/metabolism , Mice , Mice, Inbred CBA , Monocytes , RAW 264.7 Cells
6.
Am J Physiol Gastrointest Liver Physiol ; 318(3): G439-G450, 2020 03 01.
Article in English | MEDLINE | ID: mdl-31961718

ABSTRACT

Methionine is an essential amino acid needed for a variety of processes in living organisms. Ionizing radiation depletes tissue methionine concentrations and leads to the loss of DNA methylation and decreased synthesis of glutathione. In this study, we aimed to investigate the effects of methionine dietary supplementation in CBA/CaJ mice after exposure to doses ranging from 3 to 8.5 Gy of 137Cs of total body irradiation. We report that mice fed a methionine-supplemented diet (MSD; 19.5 vs. 6.5 mg/kg in a methionine-adequate diet, MAD) developed acute radiation toxicity at doses as low as 3 Gy. Partial body irradiation performed with hindlimb shielding resulted in a 50% mortality rate in MSD-fed mice exposed to 8.5 Gy, suggesting prevalence of radiation-induced gastrointestinal syndrome in the development of acute radiation toxicity. Analysis of the intestinal microbiome demonstrated shifts in the gut ecology, observed along with the development of leaky gut syndrome and bacterial translocation into the liver. Normal gut physiology impairment was facilitated by alterations in the one-carbon metabolism pathway and was exhibited as decreases in circulating citrulline levels mirrored by decreased intestinal mucosal surface area and the number of surviving crypts. In conclusion, we demonstrate that a relevant excess of methionine dietary intake exacerbates the detrimental effects of exposure to ionizing radiation in the small intestine.NEW & NOTEWORTHY Methionine supplementation, instead of an anticipated health-promoting effect, sensitizes mice to gastrointestinal radiation syndrome. Mechanistically, excess of methionine negatively affects intestinal ecology, leading to a cascade of physiological, biochemical, and molecular alterations that impair normal gut response to a clinically relevant genotoxic stressor. These findings speak toward increasing the role of registered dietitians during cancer therapy and the necessity of a solid scientific background behind the sales of dietary supplements and claims regarding their benefits.


Subject(s)
Acute Radiation Syndrome/etiology , Dietary Supplements/toxicity , Intestine, Small/drug effects , Methionine/toxicity , Radiation Injuries, Experimental/etiology , Acute Radiation Syndrome/metabolism , Acute Radiation Syndrome/microbiology , Acute Radiation Syndrome/pathology , Animals , DNA Methylation/drug effects , Dysbiosis , Energy Metabolism/drug effects , Gastrointestinal Microbiome/drug effects , Intestine, Small/metabolism , Intestine, Small/microbiology , Intestine, Small/pathology , Male , Mice, Inbred C57BL , Mice, Inbred CBA , Radiation Dosage , Radiation Injuries, Experimental/metabolism , Radiation Injuries, Experimental/microbiology , Radiation Injuries, Experimental/pathology , Risk Factors , Whole-Body Irradiation
7.
Int J Mol Sci ; 21(20)2020 Oct 21.
Article in English | MEDLINE | ID: mdl-33096940

ABSTRACT

Cannabidiol (CBD) is a biologically active, non-psychotropic component of Cannabis sativa whose popularity has grown exponentially in recent years. Besides a wealth of potential health benefits, ingestion of CBD poses risks for a number of side effects, of which hepatotoxicity and CBD/herb-drug interactions are of particular concern. Here, we investigated the interaction potential between the cannabidiol-rich cannabis extract (CRCE) and methylsulfonylmethane (MSM), a popular dietary supplement, in the mouse model. For this purpose, 8-week-old male C57BL6/J mice received MSM-containing water (80 mg/100 mL) ad libitum for 17 days. During the last three days of treatment, mice received three doses of CRCE administered in sesame oil via oral gavage (123 mg/kg/day). Administration of MSM alone did not result in any evidence of liver toxicity and did not induce expression of mouse cytochrome P450 (CYP) enzymes. Administration of CRCE did produce significant (p < 0.05) increases in Cyp1a2, Cyp2b10, Cyp2c29, Cyp3a4, Cyp3a11, Cyp2c65, and Cyp2c66 messenger RNA, however, this effect was not amplified by MSM/CRCE co-treatment. Similarly, no evidence of liver toxicity was observed in MSM/CRCE dosed mice. In conclusion, short-term MSM/CRCE co-administration did not demonstrate any evidence of hepatotoxicity in the mouse model.


Subject(s)
Cannabidiol/toxicity , Plant Extracts/toxicity , Alkaline Phosphatase/blood , Animals , Cannabidiol/pharmacokinetics , Cannabis/chemistry , Chemical and Drug Induced Liver Injury/blood , Chemical and Drug Induced Liver Injury/pathology , Cytochrome P-450 Enzyme System/metabolism , Dietary Supplements/toxicity , Glutamine/analogs & derivatives , Glutamine/metabolism , Herb-Drug Interactions , Male , Mice, Inbred C57BL , Plant Extracts/chemistry , Plant Extracts/pharmacokinetics , Taurine/analogs & derivatives , Taurine/metabolism , Toxicity Tests
8.
Molecules ; 24(9)2019 Apr 30.
Article in English | MEDLINE | ID: mdl-31052254

ABSTRACT

The goal of this study was to investigate Cannabidiol (CBD) hepatotoxicity in 8-week-old male B6C3F1 mice. Animals were gavaged with either 0, 246, 738, or 2460 mg/kg of CBD (acute toxicity, 24 h) or with daily doses of 0, 61.5, 184.5, or 615 mg/kg for 10 days (sub-acute toxicity). These doses were the allometrically scaled mouse equivalent doses (MED) of the maximum recommended human maintenance dose of CBD in EPIDIOLEX® (20 mg/kg). In the acute study, significant increases in liver-to-body weight (LBW) ratios, plasma ALT, AST, and total bilirubin were observed for the 2460 mg/kg dose. In the sub-acute study, 75% of mice gavaged with 615 mg/kg developed a moribund condition between days three and four. As in the acute phase, 615 mg/kg CBD increased LBW ratios, ALT, AST, and total bilirubin. Hepatotoxicity gene expression arrays revealed that CBD differentially regulated more than 50 genes, many of which were linked to oxidative stress responses, lipid metabolism pathways and drug metabolizing enzymes. In conclusion, CBD exhibited clear signs of hepatotoxicity, possibly of a cholestatic nature. The involvement of numerous pathways associated with lipid and xenobiotic metabolism raises serious concerns about potential drug interactions as well as the safety of CBD.


Subject(s)
Cannabidiol/chemistry , Cannabidiol/pharmacology , Cannabis/chemistry , Hepatocytes/drug effects , Plant Extracts/chemistry , Plant Extracts/pharmacology , Animals , Biomarkers , Chemical and Drug Induced Liver Injury/etiology , Chemical and Drug Induced Liver Injury/metabolism , Chemical and Drug Induced Liver Injury/pathology , Disease Models, Animal , Gene Expression Profiling , Hepatocytes/metabolism , Liver Function Tests , Mice , Transcriptome
9.
Molecules ; 24(12)2019 Jun 17.
Article in English | MEDLINE | ID: mdl-31212965

ABSTRACT

The goal of this study was to investigate the potential for a cannabidiol-rich cannabis extract (CRCE) to interact with the most common over-the-counter drug and the major known cause of drug-induced liver injury-acetaminophen (APAP)-in aged female CD-1 mice. Gavaging mice with 116 mg/kg of cannabidiol (CBD) [mouse equivalent dose (MED) of 10 mg/kg of CBD] in CRCE delivered with sesame oil for three consecutive days followed by intraperitoneally (i.p.) acetaminophen (APAP) administration (400 mg/kg) on day 4 resulted in overt toxicity with 37.5% mortality. No mortality was observed in mice treated with 290 mg/kg of CBD+APAP (MED of 25 mg/kg of CBD) or APAP alone. Following CRCE/APAP co-administration, microscopic examination revealed a sinusoidal obstruction syndrome-like liver injury-the severity of which correlated with the degree of alterations in physiological and clinical biochemistry end points. Mechanistically, glutathione depletion and oxidative stress were observed between the APAP-only and co-administration groups, but co-administration resulted in much greater activation of c-Jun N-terminal kinase (JNK). Strikingly, these effects were not observed in mice gavaged with 290 mg/kg CBD in CRCE followed by APAP administration. These findings highlight the potential for CBD/drug interactions, and reveal an interesting paradoxical effect of CBD/APAP-induced hepatotoxicity.


Subject(s)
Acetaminophen/adverse effects , Cannabidiol/adverse effects , Hepatic Veno-Occlusive Disease/diagnosis , Hepatic Veno-Occlusive Disease/etiology , Animals , Biomarkers , Cannabidiol/chemistry , Cannabis/chemistry , Chemical and Drug Induced Liver Injury/diagnosis , Chemical and Drug Induced Liver Injury/etiology , Disease Models, Animal , Dose-Response Relationship, Drug , Drug Synergism , Female , Liver/drug effects , Liver/metabolism , Liver/pathology , Mice , Mice, Inbred Strains , Phytochemicals/adverse effects , Phytochemicals/chemistry , Plant Extracts/adverse effects
10.
Carcinogenesis ; 39(9): 1117-1126, 2018 09 21.
Article in English | MEDLINE | ID: mdl-29939201

ABSTRACT

Methionine dependency describes the characteristic rapid in vitro death of most tumor cells in the absence of methionine. Combining chemotherapy with dietary methionine deprivation [methionine-deficient diet (MDD)] at tolerable levels has vast potential in tumor treatment; however, it is limited by MDD-induced toxicity during extended deprivation. Recent advances in imaging and irradiation delivery have created the field of stereotactic body radiotherapy (SBRT), where fewer large-dose fractions delivered in less time result in increased local-tumor control, which could be maximally synergistic with an MDD short course. Identification of the lowest effective methionine dietary intake not associated with toxicity will further enhance the cancer therapy potential. In this study, we investigated the effects of MDD and methionine-restricted diet (MRD) in primary and metastatic melanoma models in combination with radiotherapy (RT). In vitro, MDD dose-dependently sensitized mouse and human melanoma cell lines to RT. In vivo in mice, MDD substantially potentiated the effects of RT by a significant delay in tumor growth, in comparison with administering MDD or RT alone. The antitumor effects of an MDD/RT approach were due to effects on one-carbon metabolism, resulting in impaired methionine biotransformation via downregulation of Mat2a, which encodes methionine adenosyltransferase 2A. Furthermore, and probably most importantly, MDD and MRD substantially diminished metastatic potential; the antitumor MRD effects were not associated with toxicity to normal tissue. Our findings suggest that modulation of methionine intake holds substantial promise for use with short-course SBRT for cancer treatment.


Subject(s)
Antineoplastic Agents/pharmacology , Melanoma/diet therapy , Melanoma/pathology , Methionine Adenosyltransferase/biosynthesis , Methionine/pharmacology , Animals , Antineoplastic Agents/administration & dosage , Cell Line, Tumor , Humans , Male , Methionine/administration & dosage , Methionine/metabolism , Mice , Mice, Inbred C57BL , Neoplasm Metastasis/pathology
11.
Int J Cancer ; 142(5): 874-882, 2018 03 01.
Article in English | MEDLINE | ID: mdl-28836271

ABSTRACT

The interaction between the (epi)genetic makeup of an individual and his/her environmental exposure record (exposome) is accepted as a determinant factor for a significant proportion of human malignancies. Recent evidence has highlighted the key role of epigenetic mechanisms in mediating gene-environment interactions and translating exposures into tumorigenesis. There is also growing evidence that epigenetic changes may be risk factor-specific ("fingerprints") that should prove instrumental in the discovery of new biomarkers in cancer. Here, we review the state of the science of epigenetics associated with environmental stimuli and cancer risk, highlighting key developments in the field. Critical knowledge gaps and research needs are discussed and advances in epigenomics that may help in understanding the functional relevance of epigenetic alterations. Key elements required for causality inferences linking epigenetic changes to exposure and cancer are discussed and how these alterations can be incorporated in carcinogen evaluation and in understanding mechanisms underlying epigenome deregulation by the environment.


Subject(s)
Environmental Exposure/adverse effects , Epigenesis, Genetic , Epigenomics , Gene-Environment Interaction , Neoplasms/etiology , Animals , DNA Methylation , Humans , Neoplasms/pathology , Risk Factors
12.
Int J Mol Sci ; 18(7)2017 Jul 04.
Article in English | MEDLINE | ID: mdl-28677663

ABSTRACT

Long Interspersed Nuclear Element 1 (LINE-1) retrotransposons are the major repetitive elements in mammalian genomes. LINE-1s are well-accepted as driving forces of evolution and critical regulators of the expression of genetic information. Alterations in LINE-1 DNA methylation may lead to its aberrant activity and are reported in virtually all human cancers and in experimental carcinogenesis. In this study, we investigated the endogenous DNA methylation status of the 5' untranslated region (UTR) of LINE-1 elements in the bone marrow hematopoietic stem cells (HSCs), hematopoietic progenitor cells (HPCs), and mononuclear cells (MNCs) in radioresistant C57BL/6J and radiosensitive CBA/J mice and in response to ionizing radiation (IR). We demonstrated that basal levels of DNA methylation within the 5'-UTRs of LINE-1 elements did not differ significantly between the two mouse strains and were negatively correlated with the evolutionary age of LINE-1 elements. Meanwhile, the expression of LINE-1 elements was higher in CBA/J mice. At two months after irradiation to 0.1 or 1 Gy of 137Cs (dose rate 1.21 Gy/min), significant decreases in LINE-1 DNA methylation in HSCs were observed in prone to radiation-induced carcinogenesis CBA/J, but not C57BL/6J mice. At the same time, no residual DNA damage, increased ROS, or changes in the cell cycle were detected in HSCs of CBA/J mice. These results suggest that epigenetic alterations may potentially serve as driving forces of radiation-induced carcinogenesis; however, future studies are needed to demonstrate the direct link between the LINE-1 DNA hypomethylation and radiation carcinogenesis.


Subject(s)
DNA Methylation/radiation effects , Hematopoietic Stem Cells/metabolism , Hematopoietic Stem Cells/radiation effects , Long Interspersed Nucleotide Elements , Radiation, Ionizing , Animals , DNA Damage , Dose-Response Relationship, Radiation , Gene Expression Regulation/radiation effects , Hematopoiesis/genetics , Male , Mice , Mice, Inbred C57BL , Mice, Inbred CBA , Retroelements , Species Specificity
13.
Pharm Res ; 33(9): 2117-25, 2016 09.
Article in English | MEDLINE | ID: mdl-27216753

ABSTRACT

PURPOSE: Ionizing radiation (IR) generates reactive oxygen species (ROS), which cause DNA double-strand breaks (DSBs) that are responsible for cytogenetic alterations. Because antioxidants are potent ROS scavengers, we determined whether the vitamin E isoform γ-tocotrienol (GT3), a radio-protective multifunctional dietary antioxidant, can suppress IR-induced cytogenetic damage. METHODS: We measured DSB formation in irradiated primary human umbilical vein endothelial cells (HUVECs) by quantifying the formation of γ-H2AX foci. Chromosomal aberrations (CAs) were analyzed in irradiated HUVECs and in the bone marrow cells of irradiated mice by conventional and fluorescence-based chromosome painting techniques. Gene expression was measured in HUVECs with quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). RESULTS: GT3 pretreatment reduced DSB formation in HUVECS, and also decreased CAs in HUVECs and mouse bone marrow cells after irradiation. Moreover, GT3 increased expression of the DNA-repair gene RAD50 and attenuated radiation-induced RAD50 suppression. CONCLUSIONS: GT3 attenuates radiation-induced cytogenetic damage, possibly by affecting RAD50 expression. GT3 should be explored as a therapeutic to reduce the risk of developing genetic diseases after radiation exposure.


Subject(s)
Chromosome Aberrations/drug effects , Radiation Injuries/drug therapy , Tocotrienols/administration & dosage , Vitamin E/administration & dosage , Animals , Antioxidants/administration & dosage , Bone Marrow Cells/drug effects , Cells, Cultured , DNA Breaks, Double-Stranded/drug effects , DNA Repair/drug effects , DNA Repair Enzymes/genetics , Female , Human Umbilical Vein Endothelial Cells/drug effects , Humans , Mice , Mice, Inbred C57BL , Radiation, Ionizing
14.
Environ Res ; 150: 470-481, 2016 10.
Article in English | MEDLINE | ID: mdl-27419368

ABSTRACT

Long Interspersed Nucleotide Element 1 (LINE-1) retrotransposons are heavily methylated and are the most abundant transposable elements in mammalian genomes. Here, we investigated the differential DNA methylation within the LINE-1 under normal conditions and in response to environmentally relevant doses of sparsely and densely ionizing radiation. We demonstrate that DNA methylation of LINE-1 elements in the lungs of C57BL6 mice is dependent on their evolutionary age, where the elder age of the element is associated with the lower extent of DNA methylation. Exposure to 5-aza-2'-deoxycytidine and methionine-deficient diet affected DNA methylation of selective LINE-1 elements in an age- and promoter type-dependent manner. Exposure to densely IR, but not sparsely IR, resulted in DNA hypermethylation of older LINE-1 elements, while the DNA methylation of evolutionary younger elements remained mostly unchanged. We also demonstrate that exposure to densely IR increased mRNA and protein levels of LINE-1 via the loss of the histone H3K9 dimethylation and an increase in the H3K4 trimethylation at the LINE-1 5'-untranslated region, independently of DNA methylation. Our findings suggest that DNA methylation is important for regulation of LINE-1 expression under normal conditions, but histone modifications may dictate the transcriptional activity of LINE-1 in response to exposure to densely IR.


Subject(s)
DNA Methylation/radiation effects , Long Interspersed Nucleotide Elements/genetics , Radiation, Ionizing , Animals , Azacitidine/analogs & derivatives , Azacitidine/pharmacology , Decitabine , Histones/metabolism , Long Interspersed Nucleotide Elements/physiology , Lung/metabolism , Lung/radiation effects , Male , Mice , Mice, Inbred C57BL , RAW 264.7 Cells
16.
Carcinogenesis ; 36 Suppl 1: S128-59, 2015 Jun.
Article in English | MEDLINE | ID: mdl-26106135

ABSTRACT

The purpose of this review is to stimulate new ideas regarding low-dose environmental mixtures and carcinogens and their potential to promote invasion and metastasis. Whereas a number of chapters in this review are devoted to the role of low-dose environmental mixtures and carcinogens in the promotion of invasion and metastasis in specific tumors such as breast and prostate, the overarching theme is the role of low-dose carcinogens in the progression of cancer stem cells. It is becoming clearer that cancer stem cells in a tumor are the ones that assume invasive properties and colonize distant organs. Therefore, low-dose contaminants that trigger epithelial-mesenchymal transition, for example, in these cells are of particular interest in this review. This we hope will lead to the collaboration between scientists who have dedicated their professional life to the study of carcinogens and those whose interests are exclusively in the arena of tissue invasion and metastasis.


Subject(s)
Carcinogens, Environmental/adverse effects , Neoplasm Invasiveness/pathology , Neoplasm Metastasis/pathology , Animals , Disease Progression , Environmental Exposure/adverse effects , Epithelial-Mesenchymal Transition/drug effects , Humans
17.
J Diet Suppl ; : 1-8, 2024 Oct 25.
Article in English | MEDLINE | ID: mdl-39449550

ABSTRACT

The Dietary Supplement Health and Education Act (DSHEA) of 1994 defined the FDA's statutory authority to regulate dietary supplement products as a category of food in the United States. As we celebrate 30 years post-DSHEA, it is important to reflect on its significance for public health, influence on the continuously evolving and expanding product category, the current regulatory framework, and potential opportunities or modernizing oversight to ensure a strong and well-regulated marketplace. An estimated three-fourths of U.S. consumers report use of dietary supplements, and the product market has grown substantially since the passage of DSHEA, from approximately 4,000 products in 1994 to 80,000+ present day. This growth represents a current $60 billion domestic and $200 billion international market for dietary supplements. Scientists, public health officials, health care providers, patients, consumer advocacy organizations, and the U.S. Food and Drug Administration have all called for reform to what has been described as 'outdated' regulation of dietary supplements. Advancing at an even faster rate is published scientific evidence in the space. This special issue of the Journal of Dietary Supplements comprises a collection of articles authored by academicians, legal scholars, representatives of U.S. government agencies, and industry scientists that critically examine the successes, challenges, and opportunities for improving specific aspects of DSHEA and domestic health policy. This editorial provides historical context and milestones of dietary supplement regulation in the U.S. post-DSHEA and offers an overview of the research contained within the special issue. Advancing toward a more transparent and safer marketplace requires trustworthy supply chains, increased adherence to quality standards, additional labeling requirements, and enhancement of post-market surveillance. This special issue seeks to contribute to the broader understanding of dietary supplement regulation and its future direction.

18.
Basic Clin Pharmacol Toxicol ; 135(4): 409-416, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39197876

ABSTRACT

Phenibut is a gamma aminobutyric acid derivative with activity at γ-aminobutyric acid (GABA)B, A and ß-phenethylamine receptors. It was developed as a drug in the former Soviet Union to overcome anxiety and improve cognitive function in military personnel. In the last decade, it has made inroads into the European and U.S. markets, being marketed for purported nootropic properties. Here, we summarize the current knowledge on phenibut, its toxicology, pharmacology, adverse health effects, and patterns of use. Publications in peer-reviewed journals were searched in PubMed, Web of Science, and Google Scholar databases. Available literature points to adverse side effects associated with intoxication, withdrawal, and addiction to phenibut. Some of these effects can be life-threatening, requiring hospitalization and therapeutic interventions. Supportive efforts are often complicated by a lack of knowledge regarding phenibut's toxicology and pharmacology. Ingestion of phenibut was often associated with concomitant use of other substances of abuse. As control over its online marketing seems unrealistic, current efforts need to be focused on the addition of phenibut to current drug screening tests and the development of generally accepted treatment strategies for phenibut-associated toxicities.


Subject(s)
gamma-Aminobutyric Acid , Humans , gamma-Aminobutyric Acid/analogs & derivatives , Substance-Related Disorders , Animals , Substance Withdrawal Syndrome/drug therapy , Nootropic Agents/adverse effects , Nootropic Agents/pharmacology
19.
J Diet Suppl ; : 1-18, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38562009

ABSTRACT

Acetaminophen (APAP) overdose is one of the most common causes of acute liver injury. The current standard-of-care treatment for APAP hepatotoxicity, N-acetyl-l-cysteine, is highly effective when administered early after overdose, but loses efficacy in later-presenting patients. As a result, there is interest in the identification of new treatments for APAP overdose patients. Natural products are a promising source of new treatments because many are purported to have hepatoprotective effects. In fact, a great deal of research has been done to identify natural products that can protect against APAP-induced liver injury. However, serious concerns have been raised about the rigor and human relevance of these studies. Here, we systematically reviewed the APAP-natural product literature from 2013 to 2023 to determine the veracity of these concerns and the scope of the potential problem. The results substantiate the concerns that have been previously raised and point to concrete steps that can be taken to improve APAP-natural product research.

20.
PLoS One ; 19(10): e0312322, 2024.
Article in English | MEDLINE | ID: mdl-39471171

ABSTRACT

BACKGROUND: Scholarly publications are important indicators of research productivity and investigator development in Centers of Biomedical Research Excellence (COBREs). However, no information is available to describe implementation and evaluation of writing development programs within COBREs. Therefore, this paper aimed to evaluate the first year of a campus-wide COBRE-supported writing program. METHODS: A convergent parallel mixed-methods design (QUAN + QUAL) was used. All writing program participants were invited to complete post-participation surveys, and a subgroup was selected using purposive sampling to complete individual semi-structured interviews. Descriptive statistics were used to characterize survey data, and qualitative content analysis was employed to analyze interview data. Self-determination theory served as the theoretical framework by which themes were developed and interpreted. RESULTS: Professional staff, post-doctoral fellows, and faculty from all academic ranks (n = 29) participated in the writing program during its first year. Survey respondents (n = 18, response rate 62%) rated social support (89%), group accountability (89%), hearing group members' writing goals (78%), receiving group advice (67%), and setting a weekly writing schedule (56%) as beneficial program components. Participants rated program benefits such as breaking away from other responsibilities, staying on task with writing goals, and receiving social support as most beneficial. During interviews, participants (n = 14) described five major themes related to the benefits received: 1) belonging to a community of writers; 2) managing writing-related emotions; 3) improved productivity; 4) establishing helpful writing habits; and 5) improved motivation for scholarly writing. CONCLUSIONS: This first-year programmatic evaluation demonstrates the writing program's effectiveness as a campus-level development resource supported by a research center. Both survey and interview data affirmed that participants perceived autonomy, competence, and relatedness were supported through participation in the writing program. Participants placed particular emphasis on the writing program's successful development of a community of scholarly writers.


Subject(s)
Biomedical Research , Writing , Humans , Female , Male , Program Evaluation , Surveys and Questionnaires , Research Personnel/psychology , Universities , Faculty/psychology , Adult
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