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Technology in Cancer Research &... 2021To investigate the efficacy of a formula comprising arsenic trioxide and dimercaprol (BAL-ATO) as a radiosensitizing agent in model mice with pancreatic cancer...
OBJECTIVE
To investigate the efficacy of a formula comprising arsenic trioxide and dimercaprol (BAL-ATO) as a radiosensitizing agent in model mice with pancreatic cancer xenografts.
METHODS
Female BALB/c nude mice bearing SW1990 human pancreatic cancer xenografts were divided into four treatment arms, including control, radiotherapy (RT), BAL-ATO, and RT + BAL-ATO groups. Survival and tumor volume were analyzed. We also assessed apoptosis in tumor samples by live imaging and detected hypoxia by confocal laser microscope observation. We further investigated the mechanisms of BAL-ATO action in RT by detecting affected proteins by western blot and immunohistochemistry assays.
RESULTS
Median survival was significantly longer in the RT + BAL-ATO group (64.5 days) compared with the control (49.5 days), RT (39 days), and BAL-ATO (48 days) groups ( 0.001). RT + BAL-ATO inhibited the growth of tumors in mice by 73% compared with the control group, which was significantly higher than the rate of inhibition following RT alone (59%) ( < 0.01). Further analysis showed an improved microenvironment in terms of hypoxia in tumors treated with BAL-ATO alone or RT + BAL-ATO. Expression of signaling molecules associated with pancreatic cancer stem cells, including CD24, CD44, ALDH1A1, Gli-1, and Nestin, was detected in tumors treated with BAL-ATO alone or in combination with RT.
CONCLUSION
These data suggest that BAL-ATO function as a radiosensitizer in mice with pancreatic cancer xenografts, via mechanisms involving hypoxia reduction and inhibition of signaling pathways associated with pancreatic cancer stem cells. BAL-ATO may thus be a promising radiosensitizing agent in patients with pancreatic cancer.
Topics: Animals; Antineoplastic Agents; Arsenic Trioxide; Biomarkers; Cell Line, Tumor; Cell Proliferation; Dimercaprol; Disease Models, Animal; Drug Combinations; Drug Compounding; Female; Humans; Mice; Pancreatic Neoplasms; Prognosis; Radiation Tolerance; Radiation-Sensitizing Agents; Signal Transduction; Treatment Outcome; Xenograft Model Antitumor Assays
PubMed: 34433326
DOI: 10.1177/15330338211036324 -
Redox Biology Nov 2023Glutathione (GSH) depletion, and impaired redox homeostasis have been observed in experimental animal models and patients with epilepsy. Pleiotropic strategies that...
Glutathione (GSH) depletion, and impaired redox homeostasis have been observed in experimental animal models and patients with epilepsy. Pleiotropic strategies that elevate GSH levels via transcriptional regulation have been shown to significantly decrease oxidative stress and seizure frequency, increase seizure threshold, and rescue certain cognitive deficits. Whether elevation of GSH per se alters neuronal hyperexcitability remains unanswered. We previously showed that thiols such as dimercaprol (DMP) elevate GSH via post-translational activation of glutamate cysteine ligase (GCL), the rate limiting GSH biosynthetic enzyme. Here, we asked if elevation of cellular GSH by DMP altered neuronal hyperexcitability in-vitro and in-vivo. Treatment of primary neuronal-glial cerebrocortical cultures with DMP elevated GSH and inhibited a voltage-gated potassium channel blocker (4-aminopyridine, 4AP) induced neuronal hyperexcitability. DMP increased GSH in wildtype (WT) zebrafish larvae and significantly attenuated convulsant pentylenetetrazol (PTZ)-induced acute 'seizure-like' swim behavior. DMP treatment increased GSH and inhibited convulsive, spontaneous 'seizure-like' swim behavior in the Dravet Syndrome (DS) zebrafish larvae (scn1Lab). Furthermore, DMP treatment significantly decreased spontaneous electrographic seizures and associated seizure parameters in scn1Lab zebrafish larvae. We investigated the role of the redox-sensitive mammalian target of rapamycin (mTOR) pathway due to the presence of several cysteine-rich proteins and their involvement in regulating neuronal excitability. Treatment of primary neuronal-glial cerebrocortical cultures with 4AP or l-buthionine-(S,R)-sulfoximine (BSO), an irreversible inhibitor of GSH biosynthesis, significantly increased mTOR complex I (mTORC1) activity which was rescued by pre-treatment with DMP. Furthermore, BSO-mediated GSH depletion oxidatively modified the tuberous sclerosis protein complex (TSC) consisting of hamartin (TSC1), tuberin (TSC2), and TBC1 domain family member 7 (TBC1D7) which are critical negative regulators of mTORC1. In summary, our results suggest that DMP-mediated GSH elevation by a novel post-translational mechanism can inhibit neuronal hyperexcitability both in-vitro and in-vivo and a plausible link is the redox sensitive mTORC1 pathway.
Topics: Animals; Humans; Zebrafish; Glutathione; Glutamate-Cysteine Ligase; TOR Serine-Threonine Kinases; Mechanistic Target of Rapamycin Complex 1; Seizures; Buthionine Sulfoximine; Mammals
PubMed: 37769522
DOI: 10.1016/j.redox.2023.102895 -
International Journal of... 2005Wilson's disease (WD) is an autosomal recessive disorder characterized by copper accumulation and toxicity in the liver and in other tissues. WD presents with liver... (Review)
Review
Wilson's disease (WD) is an autosomal recessive disorder characterized by copper accumulation and toxicity in the liver and in other tissues. WD presents with liver disease, neurological or psychiatric disturbances or other less common clinical features. Diagnosis of WD is often difficult and may be formulated through clinical, biochemical, imaging, histochemical and genetic evaluations. Pharmacological approach in WD consists in copper chelating agents such as D-penicillamine, trientine, dimercaprol and tetrathiomolybdate. In 1997 zinc was approved for maintenance therapy of WD by the U.S. FDA. Orthotopic Liver Transplantation is indicated in fulminant hepatic failure, progressive hepatic insufficiency despite therapy, cirrhosis with complications of portal hypertension. However the most appropriate therapy, including OLT, remains controversial in WD and further studies are needed especially in order to differentiate the possibility of specific therapies for different WD phenotypes.
Topics: Chelating Agents; Copper; Hepatolenticular Degeneration; Humans; Liver Diseases
PubMed: 15698506
DOI: 10.1177/039463200501800102 -
Annals of the New York Academy of... Aug 2016Arsenicals are highly reactive inorganic and organic derivatives of arsenic. These chemicals are very toxic and produce both acute and chronic tissue damage. On the... (Review)
Review
Arsenicals are highly reactive inorganic and organic derivatives of arsenic. These chemicals are very toxic and produce both acute and chronic tissue damage. On the basis of these observations, and considering the low cost and simple methods of their bulk syntheses, these agents were thought to be appropriate for chemical warfare. Among these, the best-known agent that was synthesized and weaponized during World War I (WWI) is Lewisite. Exposure to Lewisite causes painful inflammatory and blistering responses in the skin, lung, and eye. These chemicals also manifest systemic tissue injury following their cutaneous exposure. Although largely discontinued after WWI, stockpiles are still known to exist in the former Soviet Union, Germany, Italy, the United States, and Asia. Thus, access by terrorists or accidental exposure could be highly dangerous for humans and the environment. This review summarizes studies that describe the biological, pathophysiological, toxicological, and environmental effects of exposure to arsenicals, with a major focus on cutaneous injury. Studies related to the development of novel molecular pathobiology-based antidotes against these agents are also described.
Topics: Animals; Arsenic Poisoning; Arsenicals; Chemical Warfare; Chemical Warfare Agents; Dimercaprol; Environmental Exposure; Humans; Oxidative Stress; Reactive Oxygen Species
PubMed: 27636894
DOI: 10.1111/nyas.13214 -
Translational Neurodegeneration Apr 2021The mechanisms underlying lesions of dopaminergic (DA) neurons, an essential pathology of Parkinson's disease (PD), are largely unknown, although oxidative stress is...
BACKGROUND
The mechanisms underlying lesions of dopaminergic (DA) neurons, an essential pathology of Parkinson's disease (PD), are largely unknown, although oxidative stress is recognized as a key factor. We have previously shown that the pro-oxidative aldehyde acrolein is a critical factor in PD pathology, and that acrolein scavenger hydralazine can reduce the elevated acrolein, mitigate DA neuron death, and alleviate motor deficits in a 6-hydroxydopamine (6-OHDA) rat model. As such, we hypothesize that a structurally distinct acrolein scavenger, dimercaprol (DP), can also offer neuroprotection and behavioral benefits.
METHODS
DP was used to lower the elevated levels of acrolein in the basal ganglia of 6-OHDA rats. The acrolein levels and related pathologies were measured by immunohistochemistry. Locomotor and behavioral effects of 6-OHDA injections and DP treatment were examined using the open field test and rotarod test. Pain was assessed using mechanical allodynia, cold hypersensitivity, and plantar tests. Finally, the effects of DP were assessed in vitro on SK-N-SH dopaminergic cells exposed to acrolein.
RESULTS
DP reduced acrolein and reversed the upregulation of pain-sensing transient receptor potential ankyrin 1 (TRPA1) channels in the substantia nigra, striatum, and cortex. DP also mitigated both motor and sensory deficits typical of PD. In addition, DP lowered acrolein and protected DA-like cells in vitro. Acrolein's ability to upregulate TRPA1 was also verified in vitro using cell lines.
CONCLUSIONS
These results further elucidated the acrolein-mediated pathogenesis and reinforced the critical role of acrolein in PD while providing strong arguments for anti-acrolein treatments as a novel and feasible strategy to combat neurodegeneration in PD. Considering the extensive involvement of acrolein in various nervous system illnesses and beyond, anti-acrolein strategies may have wide applications and broad impacts on human health.
Topics: Acrolein; Animals; Behavior, Animal; Cerebral Cortex; Dimercaprol; Dopaminergic Neurons; Hydroxydopamines; Male; Motor Activity; Neostriatum; Neuroprotective Agents; Pain; Pain Measurement; Parkinson Disease, Secondary; Rats; Rats, Sprague-Dawley; Substantia Nigra; TRPA1 Cation Channel
PubMed: 33910636
DOI: 10.1186/s40035-021-00239-0 -
Journal of Medical Toxicology :... Dec 2013Chelation for heavy metal intoxication began more than 70 years ago with the development of British anti-lewisite (BAL; dimercaprol) in wartime Britain as a potential... (Review)
Review
Chelation for heavy metal intoxication began more than 70 years ago with the development of British anti-lewisite (BAL; dimercaprol) in wartime Britain as a potential antidote the arsenical warfare agent lewisite (dichloro[2-chlorovinyl]arsine). DMPS (unithiol) and DMSA (succimer), dithiol water-soluble analogs of BAL, were developed in the Soviet Union and China in the late 1950s. These three agents have remained the mainstay of chelation treatment of arsenic and mercury intoxication for more than half a century. Animal experiments and in some instances human data indicate that the dithiol chelators enhance arsenic and mercury excretion. Controlled animal experiments support a therapeutic role for these chelators in the prompt treatment of acute poisoning by arsenic and inorganic mercury salts. Treatment should be initiated as rapidly as possible (within minutes to a few hours), as efficacy declines or disappears as the time interval between metal exposure and onset of chelation increases. DMPS and DMSA, which have a higher therapeutic index than BAL and do not redistribute arsenic or mercury to the brain, offer advantages in clinical practice. Although chelation following chronic exposure to inorganic arsenic and inorganic mercury may accelerate metal excretion and diminish metal burden in some organs, potential therapeutic efficacy in terms of decreased morbidity and mortality is largely unestablished in cases of chronic metal intoxication.
Topics: Animals; Arsenic Poisoning; Arsenicals; Chelating Agents; Chelation Therapy; Humans; Mercury Poisoning; Succimer; Treatment Outcome; Unithiol
PubMed: 24178900
DOI: 10.1007/s13181-013-0344-5 -
Journal of Neurochemistry Jun 2017Acrolein is one of the most toxic byproducts of lipid peroxidation, and it has been shown to be associated with multiple pathological processes in trauma and diseases,...
Acrolein is one of the most toxic byproducts of lipid peroxidation, and it has been shown to be associated with multiple pathological processes in trauma and diseases, including spinal cord injury, multiple sclerosis, and Alzheimer's disease. Therefore, suppressing acrolein using acrolein scavengers has been suggested as a novel strategy of neuroprotection. In an effort to identify effective acrolein scavengers, we have confirmed that dimercaprol, which possesses thiol functional groups, could bind and trap acrolein. We demonstrated the reaction between acrolein and dimercaprol in an abiotic condition by nuclear magnetic resonance spectroscopy. Specifically, dimercaprol is able to bind to both the carbon double bond and aldehyde group of acrolein. Its acrolein scavenging capability was further demonstrated by in vitro results that showed that dimercaprol could significantly protect PC-12 cells from acrolein-mediated cell death in a dose-dependent manner. Furthermore, dimercaprol, when applied systemically through intraperitoneal injection, could significantly reduce acrolein contents in spinal cord tissue following a spinal cord contusion injury in rats, a condition known to have elevated acrolein concentration. Taken together, dimercaprol may be an effective acrolein scavenger and a viable candidate for acrolein detoxification.
Topics: Acrolein; Animals; Body Weight; Cell Death; Dimercaprol; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Free Radical Scavengers; L-Lactate Dehydrogenase; Magnetic Resonance Spectroscopy; Male; PC12 Cells; Rats; Spinal Cord; Spinal Cord Injuries
PubMed: 28301040
DOI: 10.1111/jnc.14025 -
Daru : Journal of Faculty of Pharmacy,... Jun 2014Mercury poisoning cases have been reported in many parts of the world, resulting in many deaths every year. Mercury compounds are classified in different chemical types... (Review)
Review
Mercury poisoning cases have been reported in many parts of the world, resulting in many deaths every year. Mercury compounds are classified in different chemical types such as elemental, inorganic and organic forms. Long term exposure to mercury compounds from different sources e.g. water, food, soil and air lead to toxic effects on cardiovascular, pulmonary, urinary, gastrointestinal, neurological systems and skin. Mercury level can be measured in plasma, urine, feces and hair samples. Urinary concentration is a good indicator of poisoning of elemental and inorganic mercury, but organic mercury (e.g. methyl mercury) can be detected easily in feces. Gold nanoparticles (AuNPs) are a rapid, cheap and sensitive method for detection of thymine bound mercuric ions. Silver nanoparticles are used as a sensitive detector of low concentration Hg2+ ions in homogeneous aqueous solutions. Besides supportive therapy, British anti lewisite, dimercaprol (BAL), 2,3-dimercaptosuccinic acid (DMSA. succimer) and dimercaptopropanesulfoxid acid (DMPS) are currently used as chelating agents in mercury poisoning. Natural biologic scavengers such as algae, azolla and other aquatic plants possess the ability to uptake mercury traces from the environment.
Topics: Chelating Agents; Humans; Mercury; Mercury Poisoning; Metal Nanoparticles; Thymine
PubMed: 24888360
DOI: 10.1186/2008-2231-22-46 -
Experimental Biology and Medicine... Jul 2008Mercury is a major toxic metal ranked top in the Toxic Substances List. Cinnabar, which contains mercury sulfide, has been used in Chinese traditional medicines for... (Comparative Study)
Comparative Study Review
Mercury is a major toxic metal ranked top in the Toxic Substances List. Cinnabar, which contains mercury sulfide, has been used in Chinese traditional medicines for thousands of years as an ingredient in various remedies, and 40 cinnabar-containing traditional medicines are still used today. Little is known about toxicology profiles or toxicokinetics of cinnabar and cinnabar-containing traditional medicines, and the high mercury content in these Chinese medicines raises justifiably escalations of public concern. This minireview, by searching the available database of cinnabar and by comparing cinnabar with common mercurials, discusses differences in their bioavailability, disposition, and toxicity. The analysis showed that cinnabar is insoluble and poorly absorbed from the gastrointestinal tract. Absorbed mercury from cinnabar is mainly accumulated in the kidneys, resembling the disposition pattern of inorganic mercury. Heating cinnabar results in release of mercury vapor, which in turn can produce toxicity similar to inhalation of these vapors. The doses of cinnabar required to produce neurotoxicity are 1000 times higher than methyl mercury. Following long-term use of cinnabar, renal dysfunction may occur. Dimercaprol and succimer are effective chelation therapies for general mercury intoxication including cinnabar. Pharmacological studies of cinnabar suggest sedative and hypnotic effects, but the therapeutic basis of cinnabar is still not clear. In summary, cinnabar is chemically inert with a relatively low toxic potential when taken orally. In risk assessment, cinnabar is less toxic than many other forms of mercury, but the rationale for its inclusion in traditional Chinese medicines remains to be fully justified.
Topics: Dose-Response Relationship, Drug; Humans; Medicine, Chinese Traditional; Mercuric Chloride; Mercury; Mercury Compounds; Methylmercury Compounds
PubMed: 18445765
DOI: 10.3181/0712-MR-336 -
Science Progress 2013Wilson's disease is a rare autosomal recessive disease characterised by the deposition of copper in the brain, liver; cornea, and other organs. The overload of copper... (Review)
Review
Wilson's disease is a rare autosomal recessive disease characterised by the deposition of copper in the brain, liver; cornea, and other organs. The overload of copper inevitably leads to progressive liver and neurological dysfunction. Copper overload in patients with Wilson's disease is caused by impairment to the biliary route for excretion of dietary copper A combination of neurological, psychiatric and hepatic symptoms can make the diagnosis of Wilson's disease challenging. Most symptoms appear in the second and third decades of life. The disease affects between one in 30,000 and one in 100,000 individuals, and is fatal if left untreated. Five drugs are currently available to treat Wilson's disease: British Anti-Lewisite; D-penicillamine; trientine; zinc sulfate or acetate; and ammonium tetrathiomolybdate. Each drug can reduce copper levels and/or transform copper into a metabolically inert and unavailable form in the patient. The discovery and introduction of these five drugs owes more to the inspiration of a few dedicated physicians and agricultural scientists than to the resources of the pharmaceutical industry.
Topics: Brain; Chelating Agents; Copper; Cornea; Dimercaprol; Drug Discovery; Hepatolenticular Degeneration; History, 20th Century; Humans; Liver; Molybdenum; Penicillamine; Rare Diseases; Trientine; Zinc Sulfate
PubMed: 23738435
DOI: 10.3184/003685013X13587771579987