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Nathan Goodyear

Pharmacological Ascorbate Radiosensitizes Pancreatic Cancer - 0 views

  • Previous studies from our laboratory have demonstrated that pharmacological ascorbate is cytotoxic to pancreatic cancer cells while normal cells are resistant
  • Ascorbate-induced cytotoxicity is mediated by the formation of H2O2 during the oxidation of ascorbate
  • the combination of IR + ascorbate increased the concentration of intracellular H2O2
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  • Under steady-state conditions, intracellular GSH is maintained at millimolar concentrations, which keeps cells in a reduced environment and serves as the principal intracellular redox buffer when cells are subjected to an oxidative stressor including H2O2 (26). Glutathione peroxidase (GPx) activity catalyzes the reduction of H2O2 to water with the conversion of GSH to glutathione disulfide (GSSG). Under steady-state conditions, GSSG is recycled back to GSH by glutathione disulfide reductase using reducing equivalents from NADPH. However, under conditions of increased H2O2 flux, this recycling mechanism may become overwhelmed leading to a depletion of intracellular GSH (27, 28).
  • ascorbate radiosensitization can create an overwhelming oxidative stress to pancreatic cancer cells resulting in oxidation/depletion of the GSH intracellular redox buffer, resulting in cell death.
  • Treatment with the combination of ascorbate + IR significantly delayed tumor growth compared to controls or ascorbate alone
  • Ascorbate + IR also significantly increased overall survival compared to controls, IR alone or ascorbate alone
  • 54% of mice treated with the combination of IR + ascorbate had no measurable tumors
  • Glutathione is a measurable marker indicative of the oxidation state of the thiol redox buffer in cells. In severe systemic oxidative stress, the GSSG/2GSH couple may become oxidized, i.e. the concentration of GSH decreases and GSSG may increase because the capacity to recycle GSSG to GSH becomes rate-limiting
  • This suggests that the very high levels of pharmacological ascorbate in these experiments may have a pro-oxidant toward red blood cells as seen by a decrease in the capacity of the intracellular redox buffer
  • These data support the hypothesis that ascorbate radiosensitization does not cause an increase in oxidative damage from lipid-derived aldehydes to other organs.
  • Our current study demonstrates the potential for pharmacological ascorbate as a radiosensitizer in the treatment of pancreatic cancer.
  • pharmacological ascorbate enhances IR-induced cell killing and DNA fragmentation leading to induction of apoptosis in HL60 leukemia cells
  • pharmacological ascorbate significantly decreases clonogenic survival and inhibits the growth of all pancreatic cancer cell lines as a single agent, as well as sensitizes cancer cells to IR
  • Hurst et al. demonstrated that pharmacological ascorbate combined with IR leads to increased numbers of double-strand DNA breaks and cell cycle arrest when compared to either treatment alone
  • pharmacological ascorbate could serve as a “pro-drug” for the delivery of H2O2 to tumors
  • the double-strand breaks induced by H2O2 were more slowly repaired
  • The combination of ascorbate and IR provide two distinct mechanisms of action: ascorbate-induced toxicity due to extracellular production of H2O2 that then diffuses into cells and causes damage to DNA, protein, and lipids; and radiation-induced toxicity as a result of ROS-induced damage to DNA. In addition, redox metal metals like Fe2+ may play an important role in ascorbate-induced cytotoxicity. By catalyzing the oxidation of ascorbate, labile iron can enhance the rate of formation of H2O2; labile iron can also react with H2O2. Recently our group has demonstrated that pharmacological ascorbate and IR increase the labile iron in tumor homogenates from this murine model of pancreatic cancer
  • we demonstrated that ascorbate or IR alone decreased tumor growth, but the combination treatment further inhibited tumor growth, indicating that pharmacological ascorbate is an effective radiosensitizer in vivo
  • data suggest that pharmacological ascorbate may protect the gut locally by decreasing IR-induced damage to the crypt cells, and systemically, by ameliorating increases in TNF-α
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    IV vitamin C effective as radiosensitizer in pancreatic cancer.
Nathan Goodyear

Pharmacologic ascorbic acid concentrations selectively kill cancer cells: Action as a p... - 0 views

  • Taken together, these data indicate that ascorbate at concentrations achieved only by i.v. administration may be a pro-drug for formation of H2O2, and that blood can be a delivery system of the pro-drug to tissues.
  • These findings give plausibility to i.v. ascorbic acid in cancer treatment, and have unexpected implications for treatment of infections where H2O2 may be beneficial
  • pharmacologic concentrations of ascorbate killed cancer but not normal cells, that cell death was dependent only on extracellular but not intracellular ascorbate, and that killing was dependent on extracellular hydrogen peroxide (H2O2) formation with ascorbate radical as an intermediate
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  • Our data show that ascorbic acid selectively killed cancer but not normal cells, using concentrations that could only be achieved by i.v. administration
  • Ascorbate-mediated cell death was due to protein-dependent extracellular H2O2 generation, via ascorbate radical formation from ascorbate as the electron donor. Like glucose, when ascorbate is infused i.v., the resulting pharmacologic concentrations should distribute rapidly in the extracellular water space (42). We showed that such pharmacologic ascorbate concentrations in media, as a surrogate for extracellular fluid, generated ascorbate radical and H2O2. In contrast, the same pharmacologic ascorbate concentrations in whole blood generated little detectable ascorbate radical and no detectable H2O2. These findings can be accounted for by efficient and redundant H2O2 catabolic pathways in whole blood (e.g., catalase and glutathione peroxidase) relative to those in media or extracellular fluid
  • ascorbic acid administered i.v. in pharmacologic concentrations may serve as a pro-drug for H2O2 delivery to the extracellular milieu
  • H2O2 generated in blood is normally removed by catalase and glutathione peroxidase within red blood cells, with internal glutathione providing reducing equivalents
  • The electron source for glutathione is NADPH from the pentose shunt, via glucose-6-phosphate dehydrogenase. If activity of this enzyme is diminished, the predicted outcome is impaired H2O2 removal causing intravascular hemolysis, the observed clinical finding.
    • Nathan Goodyear
       
      The mechansism here is inadequate recycling of GSH due to lack of G6PD, build up of intracellular H2O2 and RBC lysis--hemolysis.
  • Only recently has it been understood that the discordant clinical findings can be explained by previously unrecognized fundamental pharmacokinetics properties of ascorbate
  • Intracellular transport of ascorbate is tightly controlled in relation to extracellular concentration
  • Intravenous ascorbate infusion is expected to drastically change extracellular but not intracellular concentrations
  • For i.v. ascorbate to be clinically useful in killing cancer cells, pharmacologic but not physiologic extracellular concentrations should be effective, independent of intracellular ascorbate concentrations.
    • Nathan Goodyear
       
      accumulation of extracellular vitamin C is the effect.
  • It is unknown why ascorbate, via H2O2, killed some cancer cells but not normal cells.
  • There was no correlation with ascorbate-induced cell death and glutathione, catalase activity, or glutathione peroxidase activity.
  • H2O2, as the product of pharmacologic ascorbate concentrations, has potential therapeutic uses in addition to cancer treatment, especially in infections
  • Neutrophils generate H2O2 from superoxide,
  • i.v. ascorbate is effective in some viral infections
  • H2O2 is toxic to hepatitis C
  • Use of ascorbate as an H2O2-delivery system against sensitive pathogens, viral or bacterial, has substantial clinical implications that deserve rapid exploration.
  • Recent pharmacokinetics studies in men and women show that 10 g of ascorbate given i.v. is expected to produce plasma concentrations of nearly 6 mM, which are >25-fold higher than those concentrations from the same oral dose
  • As much as a 70-fold difference in plasma concentrations is expected between oral and i.v. administration,
  • Complementary and alternative medicine practitioners worldwide currently use ascorbate i.v. in some patients, in part because there is no apparent harm
  • Human Burkitt's lymphoma cells
  • We first investigated whether ascorbate in pharmacologic concentrations selectively affected the survival of cancer cells by studying nine cancer cell lines
  • Clinical pharmacokinetics analyses show that pharmacologic concentrations of plasma ascorbate, from 0.3 to 15 mM, are achievable only from i.v. administration
  • plasma ascorbate concentrations from maximum possible oral doses cannot exceed 0.22 mM because of limited intestinal absorption
  • For five of the nine cancer cell lines, ascorbate concentrations causing a 50% decrease in cell survival (EC50 values) were less than 5 mM, a concentration easily achievable from i.v. infusion
  • All tested normal cells were insensitive to 20 mM ascorbate.
    • Nathan Goodyear
       
      meaning safe.
  • Lymphoma cells were selected because of their sensitivity to ascorbate
  • As ascorbate concentration increased, the pattern of death changed from apoptosis to pyknosis/necrosis, a pattern suggestive of H2O2-mediated cell death
  • Apoptosis occurred by 6 h after exposure, and cell death by pyknosis was ≈90% at 14 h after exposure
    • Nathan Goodyear
       
      work continued beyond the IVC therapy itself
  • In contrast to lymphoma cells, there was little or no killing of normal lymphocytes and monocytes by ascorbate
  • Ascorbate is transported into cells as such by sodium-dependent transporters, whereas dehydroascorbic acid is transported into cells by glucose transporters and then immediately reduced internally to ascorbate
  • Whether or not intracellular ascorbate was preloaded, extracellular ascorbate induced the same amount and type of death.
  • extracellular ascorbate in pharmacologic concentrations mediates death of lymphoma cells by apoptosis and pyknosis/necrosis, independently of intracellular ascorbate.
  • H2O2 as the effector species mediating pharmacologic ascorbate-induced cell death
  • Superoxide dismutase was not protective
  • Because these data implicated H2O2 in cell killing, we added H2O2 to lymphoma cells and studied death patterns using nuclear staining (19, 28). The death patterns found with exogenous H2O2 exposure were similar to those found with ascorbate
  • For both ascorbate and H2O2, death changed from apoptosis to pyknosis/necrosis as concentrations increased
  • Sensitivity to direct exposure to H2O2 was greater in lymphoma cells compared with normal lymphocytes and normal monocytes
  • There was no association between the EC50 for ascorbate-mediated cell death and intracellular glutathione concentrations, catalase activity, or glutathione peroxidase activity
  • H2O2 generation was dependent on time, ascorbate concentration, and the presence of trace amounts of serum in media
  • ascorbate radical is a surrogate marker for H2O2 formation.
  • whatever H2O2 is generated should be removed by glutathione peroxidase and catalase within red blood cells, because H2O2 is membrane permeable
  • The data are consistent with the hypothesis that ascorbate in pharmacologic concentrations is a pro-drug for H2O2 generation in the extracellular milieu but not in blood.
  • The occurrence of one predicted complication, oxalate kidney stones, is controversial
  • In patients with glucose-6-phosphate dehydrogenase deficiency, i.v. ascorbate is contraindicated because it causes intravascular hemolysis
  • ascorbate at pharmacologic concentrations in blood is a pro-drug for H2O2 delivery to tissues.
  • ascorbate, an electron-donor in such reactions, ironically initiates pro-oxidant chemistry and H2O2 formation
  • data here showed that ascorbate initiated H2O2 formation extracellularly, but H2O2 targets could be either intracellular or extracellular, because H2O2 is membrane permeant
    • Nathan Goodyear
       
      the conversion of ascorbate to H2O2 occurs extracellular
  • More than 100 patients have been described, presumably without glucose-6-phosphate dehydrogenase deficiency, who received 10 g or more of i.v. ascorbate with no reported adverse effects other than tumor lysis
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    IV vitamin C benefits cancer patients
Nathan Goodyear

Vitamin C and cancer revisited - 0 views

  • It is well known that vitamin C, or ascorbic acid, is an effective biologic antioxidant and does not act as a pro-oxidant under normal conditions (5) because it does not readily autoxidize, i.e., react with oxygen (O2) to produce reactive oxygen species, such as superoxide radicals (O2•−) or H2O2
  • However, ascorbate readily donates an electron to redox-active transition metal ions, such as cupric (Cu2+) or ferric (Fe3+) ions, reducing them to cuprous (Cu+) and ferrous (Fe2+) ions, respectively
  • Reduced transition metal ions, in contrast to ascorbic acid, readily react with O2, reducing it to superoxide radicals (Reaction 2), which in turn dismutate to form H2O2 and O2
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  • The H2O2 produced this way (Reactions 1–3) seems to be key to ascorbate's antitumor effect because H2O2 causes cancer cells to undergo apoptosis, pyknosis, and necrosis
  • In contrast, normal cells are considerably less vulnerable to H2O2
  • The reason for the increased sensitivity of tumor cells to H2O2 is not clear but may be due to lower antioxidant defenses
  • In fact, a lower capacity to destroy H2O2—e.g., by catalase, peroxiredoxins, and GSH peroxidases—may cause tumor cells to grow and proliferate more rapidly than normal cells in response to low concentrations of H2O2
  • These observations, combined with the inhibitory effect on xenograft growth, provide the proof of concept that millimolar concentrations of extracellular ascorbate, achievable by i.p. injection or i.v. infusion in experimental animals and humans, respectively, exert pro-oxidant, antitumor effects in vivo.
  • They also show that the concentration of the ascorbyl radical correlates with the concentration of H2O2 in interstitial fluid, whereas no H2O2 can be detected in blood or plasma
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    review of the mechanism of how extracellular AA, only obtainable from parenteral dosing, can produce H2O2 extracellularly to then be cytotoxic to cancer cells.
Nathan Goodyear

Sex hormones affect neurotransmitters and shape the adult female brain during hormonal ... - 0 views

  • estrogen administration has been found to increase tryptophan hydroxylase
  • 5-HT2A mRNA levels in brain areas relevant for the control of mood, mental state and cognition (Sumner and Fink, 1998) and 5-HTT mRNA when administered for a longer period
  • n the other hand, estrogen treatment has also been observed to decrease mRNA related to serotonergic neurotransmission
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  • Furthermore, acute estrogen administration decreases 5-HTT mRNA levels (Pecins-Thompson et al., 1998) and 5-HT1A mRNA levels and binding
  • assigning the effects of estrogen on serotonin to a homogenous functional class of stimulation or inhibition seems not to be feasible
  • Progesterone has been suggested to increase serotonergic neurotransmission via the regulation of the expression of serotonin-related genes and proteins
  • menopausal women gain less benefit from antidepressant treatments compared to women during their reproductive years
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    good review of the relationship of the sex hormones and neurotransmitters.
Nathan Goodyear

Demystified . . . Human endogenous retroviruses - 0 views

  • HERVs have been inherited by successive generations and it is possible that some have conferred biological benefits
  • However, several HERVs have been implicated in certain cancers and autoimmune diseases
  • HERVs constitute about 1% of the human genome
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  • Human endogenous retroviruses (HERVs) represent footprints of previous retroviral infection and have been termed “fossil viruses”
  • HERVs possess a similar genomic organisation to present day exogenous retroviruses such as human immunodeficiency virus (HIV) and human T cell leukaemia virus (HTLV)
  • Retroviruses in effect are retrograde, because the flow of genetic information is reversed compared with the normal pathway of molecular biosynthesis—DNA → RNA → protein. Indeed, all retroviruses necessitate the conversion of viral RNA into a cDNA intermediary, which is catalysed by the enzyme reverse transcriptase
  • Overall, human endogenous retroviruses constitute about 1% of the human genome”
  • some HERVs have been implicated in certain autoimmune diseases and cancers
  • A unit of sugar, phosphate, and base is strictly termed a nucleotide
  • human genes are composed of exons, which are transcribed and translated into amino acids
  • introns, which are interspersed between exons and represent non-translated regions that contribute to the large size of some genes
  • convincing argument for the possible involvement of HERVs in malignancy
  • HERVs may be involved in carcinogenesis by virtue of the expression of HERV mRNA,26 functional proteins,27 or retroviral-like particles
  • They may also be associated with the generation of new promoters29 or the activation of proto-oncogenes
  • inhibition of an effective immune response,
  • encode immunosuppressive proteins
  • “It has been suggested that HERV-K may be important in the progression of testicular germ cell tumours through inhibition of an effective immune response”
  • HERV-K might be important in the pathogenesis of human breast cancer
  • activation of proto-oncogenes of the ras family is common in many tumour types, and some studies have suggested a potential role for HERVs in ras activation
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    good review of HERVs.
Nathan Goodyear

Improved leukemia-free survival after postconsolidation immunotherapy with histamine di... - 0 views

  • several independent lines of evidence suggest that cytotoxic effector cells such as T cells and natural killer (NK) cells participate in protecting patients with AML against relapse
  • A plethora of mechanisms have been proposed to account for the dysfunctional antileukemic lymphocytes in AML, including the production of T-cell- and NK-cell-inhibitory factors by AML blasts,48 a deficient expression of NK-cell receptors on leukemic cells,49 inhibition of antileukemic lymphocytes by mononuclear phagocytes,4 and an impaired stimulatory interaction between the CD28 antigen expressed by T cells and contact antigens on AML blasts
  • This trial met the primary endpoint and thus showed a significantly improved LFS for patients receiving HDC/IL-2 as compared with the current standard of care
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  • T cells and NK cells with antileukemic activity can be recovered from most patients with AML in remission not receiving a transplant,
  • The present study evaluated an approach to immunotherapy in AML in which IL-2 is supplemented with histamine dihydrochloride (HDC) to enhance the function of cytotoxic antileukemic lymphocytes
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    IL-2 plus histamine in patients with AML complete remission improves leukemia free survival.
Nathan Goodyear

Doxycycline and other tetracyclines in the treatment of bone... : Anti-Cancer Drugs - 0 views

  • This hypothesis has now been confirmed by experimental evidence showing that doxycycline reduces tumor burden in a mouse model of breast cancer-derived osteolytic bone metastasis
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    Doxycycline inhibits MMPs, matrix metalloproteinases, and also inhibits tumor burden.
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Pediatric Wheelchair - 0 views

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Nathan Goodyear

Minireview: Inflammation and Obesity Pathogenesis: The Hypothalamus Heats Up - 0 views

  • Leptin, secreted by adipocytes in proportion to body fat mass
  • The saturated fatty acid palmitate (16:0) induces NF-κB signaling through a TLR4-dependent mechanism
  • 18:0 (stearic) and longer saturated fatty acids as well as linolenic acid (18:3) increased proinflammatory cytokines, ER stress markers, and TLR4 activation
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  • (SOCS)-3. A member of a protein family originally characterized as negative feedback regulators of inflammation (13, 37), SOCS3 inhibits insulin and leptin signaling
  • IKKβ signaling in discrete neuronal subsets appears to be required for both hypothalamic inflammation and excess weight gain to occur during HF feeding
  • the paradoxical observation that hyperphagia and weight gain occur when hypothalamic inflammation is induced by HF feeding, yet when it occurs in response to systemic or local inflammatory processes (e.g. administration of endotoxin), anorexia and weight loss are the rule
  • , serves as a circulating signal of energy stores in part by providing feedback inhibition of hypothalamic orexigenic pathways [e.g. neurons that express neuropeptide Y and agouti-related peptide (AgRP)]
  • and stimulating anorexigenic neurons
  • signals from Toll-like receptors (TLRs), evolutionarily conserved pattern recognition molecules critical for detecting pathogens, amplified through signaling intermediates such as MyD88 activate the inhibitor of κB-kinase-β (IKKβ)/nuclear factor-κB (NF-κB), c-Jun N-terminal kinase (Jnk) and other intracellular inflammatory signals in response to stimulation by circulating saturated fatty acids
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    great read on the current understanding of how obesity and resultant inflammation disrupts hypothalamic function.
Windows Customer Support Number

1-800-485-4057 Windows technical support number - San Jose computer services - backpage... - 0 views

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    Windows tech support offers the world class services to all our Windows software clients and help you to resolve all the queries for all the windows software issues, just call us on Windows technical support number 1-800-485-4057 and also visit our websites as http://technicalsupportnumberforwindows.com
Nathan Goodyear

Beta Glucan: Health Benefits in Obesity and Metabolic Syndrome - 0 views

  • beta glucan (β-glucan), which is a dietary fiber readily found in oat and barley bran
  • Among cereals, the highest content (g per 100 g dry weight) of β-glucan has been reported for barley: 2–20 g (65% is water-soluble fraction) and for oats: 3–8 g (82% is water-soluble fraction). Other cereals also contain β-glucan but in much lower amounts: sorghum 1.1–6.2 g, rye 1.3–2.7 g, maize 0.8–1.7 g, triticale 0.3–1.2 g, wheat 0.5–1.0 g, durum wheat 0.5-0.6 g, and rice 0.13 g
  • Other sources of β-glucan include some types of seaweed [17] and various species of mushrooms such as Reishi, Shiitake, and Maitake [18].
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  • Distinction between soluble and insoluble dietary fibers is based on the solubility characteristics of dietary fiber in hot aqueous buffer solutions
  • Insoluble fibers primarily consist of cellulose and some hemicelluloses, resistant starch, and chitin while soluble fibers include pectins, β-glucans, galactomannan gums, mucilages, and some hemicelluloses
  • insoluble fibers increase fecal bulk and the excretion of bile acids and decrease intestinal transit time
  • Soluble fibers increase total transit time by delaying gastric emptying and also slow glucose absorption
  • only soluble viscous fibers delay gastric emptying time and slow glucose absorption while nonviscous soluble fibers primarily act as a substrate for microbial fermentation in the colon
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    good review on Beta glucan.
Alan Rann

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Windows Customer Support Number

Windows support number 1-800-261-4071 - 0 views

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    We are offering the world class tech support services for all Windows software issues, if you facing any type of issues such as Windows update issues, windows repair, new windows installation, uninstallation and reinstallation etc, just dial our Windows support number 1-800-261-4071
Nathan Goodyear

Deficient Glutathione in the Pathophysiology of Mycotoxin-Related Illness - 0 views

  • Decreased function of the enzymes of glutathione production results in a microenvironment depleted of glutathione on a chronic basis
  • In humans, deficiency of glutathione can lead to chronic conditions [97], including chronic asthma
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    Mycotoxins deplete glutathione production and this depletion of glutathione is a portion go the toxicity/ill effects related to mycotoxins.  This article also points to evidence that glutathione can actually be employed in the treatment of mycotoxin related conditions/illnesses.
Nathan Goodyear

Interleukin 10(IL-10) inhibits cytokine synthesis by human monocytes: an autoregulatory... - 0 views

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    role of IL-10 cytokine.  IL-10 down regulates  monocyte inflammatory cytokines and class II MHC.  The source of IL-10 is now known to be Treg cells (Th3).  Interesting, viruses can produce a similar IL-10 to suppress the immune reaction.
Nathan Goodyear

The 4-Pregnene and 5α-Pregnane Progesterone Metabolites Formed in Nontumorous... - 0 views

  • We report here the first evidence that tumorous breast tissue exhibits elevated 5α-reductase activity, which promotes significant increases in 5α-pregnanes, especially 5αP,4 whereas the normal (nontumorous) breast tissue produces more 4-pregnenes, especially 3αHP
  • 3αHP and other 4-pregnenes inhibit, whereas 5αP and other 5α-pregnanes stimulate, breast cell proliferation and detachment
  • it is evident that breast tissue can convert progesterone into two classes of metabolites: the δ-4-pregnenes (which retain the C4–5 double bond), and the 5α-reduced 21-carbon steroids (5α-pregnanes)
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  • irreversible action of 5α-reductase
  • in normal (nontumorous) breast tissue, the 4-pregnene metabolites of progesterone greatly exceeded the 5α-pregnanes, whereas in tumorous tissue, 5α-pregnanes exceeded 4-pregnenes.
  • These differences in 5α-pregnane and 4-pregnene amounts were largely attributable to differences in 5αP and 3αHP production in tumorous and nontumorous tissues
  • the metabolic activities were in general similar, regardless of the age and ER state of the patient or whether she was pre- or postmenopausal.
  • These findings suggest greatly elevated 5α-reductase activity in tumorous, as compared with nontumorous, breast tissue.
  • progesterone metabolites that retain the C-4 double bond (i.e., the 4-pregnenes) exert an antiproliferative effect in the three cell lines that were tested, whereas the 5α-pregnanes stimulate breast cell line proliferation.
  • the degree of mitogenicity would be determined by the ratio of 5α-pregnanes:4-pregnenes. Tissues with a high 4-pregnene:5α-pregnane ratio would maintain a higher degree of normalcy, whereas those with a high 5α-pregnane:4-pregnene ratio would tend toward tumorigenicity
  • The observations that progesterone metabolites affect both ER-positive and ER-negative cells as well as tumorigenic (MCF-7) and nontumorigenic (MCF-10A) cells strengthen the argument that these factors may be endocrinologically relevant for all forms of breast cancer.
  • progesterone metabolites as the active endocrine/paracrine/autocrine factors
  • Estrogen-based therapies elicit responses in only one-third of all breast cancer patients, and most of these show relapse.
  • the metabolic activities were in general similar, regardless of the age and ER state of the patient or whether she was pre- or postmenopausal.
    • Nathan Goodyear
       
      Interesting that the effect of progesterone metabolites were found to be independent from ER status, age, and pre/post menopause
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    Different progesterone metabolites shown to have different tumor effects.  Implications are that, just as estrogen metabolism effects cancer risk, so does progesterone metabolism.
Nathan Goodyear

The Complex Role of Estrogens in Inflammation - 0 views

  • These studies suggest inflammation-dependent up-regulation of ERβ relative to ERα.
  • up-regulation of ERβ relative to ERα under hypoxic conditions, which might lead to a preponderance of signaling through ERβ pathways
  • it seems that E2 at periovulatory to pregnancy levels inhibited proinflammatory cytokines from PBMCs
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  • it is clear that E2 can stimulate antibody production by B cells, probably by inhibiting T cell suppression of B cells
  • In cycling women, the largest quantities of Ig were detected before ovulation
  • In contrast, E2 at high concentrations leads to a suppression of B-lymphocyte lineage precursors
  • E2 at periovulatory to pregnancy serum levels is able to stimulate antibody secretion under healthy conditions but also in autoimmune diseases, whereas similar serum levels of E2 lead to a suppression of bone marrow B cell lineage precursors
  • In chronic inflammatory disorders, where B cells play a decisive role, E2 would promote the disease when autoaggressive B cells are already present, whereas chronically elevated E2 would inhibit initiation of an autoimmune disease when no such B cells are available. This might be a good reason why particularly B cell-dependent diseases such as SLE, mixed connective tissue disease (Sharp syndrome), IgA nephropathy, dermatitis herpetiformis, gluten sensitive enteropathy, myasthenia gravis, and thyroiditis appear in women in the reproductive years, predominantly, in the third or fourth decades of life
  • Th17 cells are thought to be the main responsible cells for chronic inflammatory tissue destruction in autoimmune diseases
  • IFN-γ, IL-12, and TNF were allocated to Th1 reactions
  • IL-4, IL-5, and IL-10 to Th2 responses
  • antiinflammatory T regulatory cells producing TGF-β and proinflammatory T helper type 17 cells (Th17) producing IL-17
  • no direct effects of estrogens on Th17 cells or IL-17 secretion have been described until now.
  • So-called Th17 cells producing IL-17 are the main T cells responsible for chronic inflammation.
  • Because IFN-γ has been allocated a Th17-inhibiting role (Fig. 1⇑), its increase by E2 at pregnancy doses and the E2-mediated inhibition of TNF must be viewed as a favorable effect in chronic inflammation
  • in humans and mice, E2 at periovulatory to pregnancy levels stimulates IL-4, IL-10, and IFN-γ but inhibits TNF from CD4+ T cells
  • In humans and mice, E3 and E2, respectively, at pregnancy levels inhibit T cell-dependent delayed type hypersensitivity
  • increased IL-4, IL-10, and IFN-γ in the presence of low TNF support an antiaggressive immune response
  • secretion of IL-1β is increased at periovulatory/proestrus to early pregnancy levels, whereas IL-1 secretion is inhibited at high pregnancy levels
  • The dichotomous effect of E2 on IL-1β and TNF at high and low concentrations is most probably due to inhibition of NF-κB at high concentrations
  • experiments with mouse and rat macroglial and microglial cells demonstrate that E2 at proestrus to pregnancy levels exerts neuroprotective effects by increasing TGF-β and by inhibiting iNOS and NO release, and reducing expression of proinflammatory cytokines and prostaglandin E2 production.
  • E2 at periovulatory to pregnancy levels inhibits NF-κB activation, which must be viewed as an antiinflammatory signal
  • It was shown that E2 concentrations equal to or above 10−10 m are necessary to inhibit NF-κB activation
  • important proinflammatory cytokines are typically inhibited at periovulatory (proestrus) to pregnancy levels of E2, which is evident for IL-6, IL-8, and TNF
  • low E2 concentrations were demonstrated to have no or even stimulatory effects
  • This renders a woman in the postmenopausal phase to a more proinflammatory situation
  • most in vitro studies demonstrated a stimulatory effect of E2 on secretion of IL-4, IL-10, and TGF-β typically at periovulatory to pregnancy levels
  • E2 at periovulatory to pregnancy levels has an ameliorating effect on chronic inflammatory diseases as long as B cell-dependent immunity or an overshooting fibrotic tissue repair process do not play a crucial pathogenic role. However, when the B cell plays an important role, E2 might even stimulate the disease process as substantiated by flare-ups in SLE during pregnancy
    • Nathan Goodyear
       
      SLE, mixed connective tissue disease (Sharp syndrome), IgA nephropathy, dermatitis herpetiformis, gluten sensitive enteropathy, myasthenia gravis, and thyroiditis
  • Short-term administration of E2 at pregnancy levels was shown to induce an inflammatory response specific to the lateral prostate of the castrated male rat
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    great review of the complex interaction between Estrogens and inflammation.  Reference here is in females.
Nathan Goodyear

JAMA Network | Archives of Internal Medicine | Statin Use and Risk of Diabetes Mellitus... - 0 views

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    women using statin therapy to lower cholesterol have increased type II Diabetes.  Variables were accounted for and this existed across all classes of statins.
Nathan Goodyear

An endocrine pathway in the prostate, ERβ, AR, 5α-androstane-3β,17β-diol, and... - 0 views

  • Although the prostate is an androgen-dependent tissue, estrogens influence both normal functions and pathological changes in this gland
  • This dual action may be due to the existence of two estrogen receptors, ERα and ERβ
  • ERα and ERβ have similar affinities for estradiol-17β
  • ...6 more annotations...
  • In this study we have shown that regulation of the levels of 3βAdiol by CYP7B1 is a key factor in regulation of prostatic growth
  • We provide evidence that proliferating cells in the prostate epithelium have elevated levels of AR and that AR protein but not mRNA levels are regulated by ERβ and its ligand 3βAdiol in the prostate epithelium.
  • because inhibition of 5α-reductase causes accumulation of testosterone and removal of ERβ action increases the level of AR in the prostate, the overall effect of Finasteride would be to favor proliferation of the prostate epithelium
  • studies show that ERβ tends to be lost in advanced prostate cancer.
  • DHEA is converted in the body to 5-androstene-3β,17β-diol, which is also a ligand for estrogen receptors (25, 39) and a substrate for CYP7B1
  • At the peak of proliferation, the proliferating epithelial cells in the ventral prostate expressed high levels of CYP7B1 but had no detectable ERβ, whereas in nonproliferating cells the level of ERβ was high and that of CYP7B1 was low.
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    3-beta androstanediola, a product of 3alpha-HSD from DHT binds to ER beta and down regulates AR in prostate cancer.  This study proposes that the mechanism is via CYP7B1.  CYP7B1 inactivates 3-beta androstanediol.  Interesting, because 3-beta androstanediol is considered "inactive" when compared to 3-alpha androstanediol and its interaction with ER alpha.  
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