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Nathan Goodyear

Estrogen Metabolism and Risk of Breast Cancer in Postmenopausal Women - 0 views

  • The ratio of the 2-hydroxylation pathway to parent estrogens was associated with a statistically significantly decreased risk of breast cancer
  • In this study, this ratio was more strongly associated with the risk of breast cancer compared with the ratio of 2-hydroxylation pathway to 16-hydroxylation pathway or unconjugated estradiol alone
  • 2-hydroxylation pathway catechols have relatively low affinities for estrogen receptors (4) and are rapidly cleared from circulation
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  • In this study, the ratio of the 2-hydroxylation pathway to the 16-hydroxylation pathway was associated with a non-statistically significantly decreased risk of breast cancer
  • In this study, the ratio of catechols to methylated catechols in the 4-hydroxylation pathway was associated with statistically significantly increased risk of breast cancer.
  • This result is consistent with the hypothesis that mutagenic quinones derived from 4-hydroxylation pathway catechols contribute to pathogenesis of postmenopausal breast cancer.
  • Catechols in both the 2- and 4-hydroxylation pathways can be oxidized to form quinones; these reactive electrophiles can then react with DNA to form a variety of adducts
  • Methylation of the catechols prevents their conversion to reactive quinones
  • the most common DNA adducts derived from 4-hydroxylation pathway catechols are depurinating and highly mutagenic (7,40), most of those derived from 2-hydroxylation pathway catechols are stable and can be repaired with little error
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    Lower 2-OH estrone metabolism associated with lower risk of breast cancer, but 4-OH estrone associated with increased risk of breast cancer.
Nathan Goodyear

Urinary Estrogens and Estrogen Metabolites and Subsequent Risk of Breast Cancer among P... - 0 views

  • both 2- and 4-catechol estrogen metabolites bind to the ER with affinities comparable with estradiol, 4-catechol estrogen metabolites have lower dissociation rates than estradiol and an enhanced ability to upregulate ER-dependent processes
  • 2-catechol estrogen metabolites act as either weak mitogens (39) or weak inhibitors of cell proliferation
  • While 16α-hydroxyestrone binds to the ER with lower affinity than estradiol, it binds covalently (41) and leads to a constitutively activated ER
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  • 4-hydroxyestradiol and 16α-hydroxyestrone increasing proliferation and decreasing apoptosis in a manner similar to estradiol; however, these effects were achieved only at concentrations 10-fold higher than estradiol (39). In contrast, 2-hydroxyestradiol did not have substantial proliferative or antiapoptotic effects
  • In our study, the associations with both 2-hydroxyestrone and 16α-hydroxyestrone were nonsignificantly inverse and we did not observe a consistent trend or significant associations between the 2-hydroxyestrone:16α-hydroxyestrone ratio and breast cancer risk
  • Ratios of the 3 hydroxylation pathways were not significantly associated with risk although the 2:16-pathway and 4:16-pathway ratios were suggestively inversely associated
  • a significant inverse association with the ratio of parent estrogens to estrogen metabolites
  • several potentially estrogenic and genotoxic mechanisms
  • Estrogen metabolites also can be genotoxic
  • Catechol estrogens can be oxidized into quinones and induce DNA damage directly through the formation of DNA adducts, or indirectly via redox cycling and generation of reactive oxygen species
  • the oxidized forms of the catechol estrogens differ in their ability to damage DNA through adducts, with oxidized 2-catechols forming stable and reversible DNA adducts and oxidized 4-catechols forming unstable adducts, which lead to depurination and mutations
  • 2- and 4-catechols have been shown to produce reactive oxygen species and induce oxidative DNA damage
  • act independently from the ER
  • 16α-Hydroxyestrone also may be genotoxic
  • While the catechol estrogens have estrogenic and genotoxic potential, the methylated catechol estrogens, which are catechol estrogens with one hydroxyl group methylated, have been hypothesized to lower the risk of breast cancer
  • The suggested mechanisms are indirect, by decreasing circulating levels of catechol estrogens and thereby the opportunity for catechols to exert genotoxic or proliferative effects, or direct, by inhibiting tumor growth and inducing apoptosis
  • the balance between phase I (oxidation) and phase II (methylation) metabolism of estrogen may be important in hormonally related cancer development.
  • Despite the estrogenic and genotoxic potential of many of the estrogen metabolites, we only observed a significantly increased breast cancer risk with one estrogen metabolite, 17-epiestriol, which has particularly strong estrogenic activity and binds to both ERα and ERβ with an affinity comparable with estradiol
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    review of estrogen metabolites and breast cancer risk in premenopausal women.
Nathan Goodyear

Urinary estrogens and estrogen metabolites and subsequent risk of breast cancer among p... - 0 views

  • While the catechol estrogens have estrogenic and genotoxic potential, the methylated catechol estrogens, which are catechol estrogens with one hydroxyl group methylated, have been hypothesized to lower risk of breast cancer.
  • Despite the estrogenic and genotoxic potential of many of the EM, we only observed a significantly increased breast cancer risk with one EM, 17-epiestriol, which has particularly strong estrogenic activity and binds to both ERα and ERβ with an affinity comparable to estradiol
  • We did not observe reduced risk for higher concentrations of 2-pathway EM relative to 16-pathway EM, nor did we observe a consistent benefit of higher concentrations of methylated catechol EM compared with catechol EM.
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  • EM also can be genotoxic, but the individual EM vary in their ability to induce DNA damage
  • Catechol estrogens can be oxidized into quinones and induce DNA damage directly through the formation of DNA adducts, or indirectly via redox cycling and generation of reactive oxygen species
  • the oxidized forms of the catechol estrogens differ in their ability to damage DNA through adducts, with oxidized 2-catechols forming stable and reversible DNA adducts and oxidized 4-catechols forming unstable adducts, which lead to depurination and mutations
  • 2- and 4-catechols have been shown to produce reactive oxygen species and induce oxidative DNA damage (46). These catechols also induce neoplastic transformation in ER-cells, and thus act independently from the ER
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    Estrogen metabolites.
Nathan Goodyear

Salivary Testosterone and a Trinucleotide (CAG) Length Polymorphism in the Androgen Rec... - 0 views

  • Testosterone correlated inversely with participant age (r = −0.39, p = 0.012) and positively with number of CAG repeats
  • transactivation potential of the AR appears to decline in graded relation to an increasing number of CAG repeats, which are distributed over a normative range of 11–37 and, in Caucasian populations, commonly average 21–22 repeats
  • When activated by androgens, ARs translocate to the cell nucleus, where they exert transcriptional control of androgen-dependent genes by binding to androgen response elements within gene regulatory sequences
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  • some evidence suggests a high number of CAG repeats may be associated with cognitive aging
  • androgens (like other steroid hormones) promote or repress the expression of genes specifying an array of cellular proteins
  • diurnal variation in testosterone levels
  • salivary testosterone correlated negatively with participant age and positively with CAG length variation in the AR gene
  • CAG repeat number varied inversely with reactivity of the ventral amygdala to facial expressions of negative affect
  • higher salivary testosterone was likewise associated with a greater number of AR CAG repeats
  • relative androgen insensitivity in ARs with a larger number of CAG repeats
  • Because circulating testosterone is regulated via negative feedback through the hypothalamic-pituitary-gonadal axis, diminished androgen sensitivity at higher CAG repeat lengths may reduce feedback suppression of luteinizing hormone (LH). LH would then be maintained at higher levels, in turn promoting higher testosterone production
  • Testosterone up-regulates AVP expression in the amygdala
  • Oxytocin exerts an inhibitory influence on AVP expression in the central amygdala, and the synthesis of oxytocin is mediated by estrogen and estrogen receptors
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    Study used saliva to measure Testosterone levels in men.  Testosterone levels were inversely associated with age, but positively associated with CAG repeat sequences in the AR.
Nathan Goodyear

Effect of chronic stress associated with unemploym... [Psychosom Med. 1995 Sep-Oct] - P... - 0 views

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    salivary testing of cortisol proven to be reliable method to evaluate/follow daily stress reactivity
Nathan Goodyear

Oxidative stress, mitochondrial dysfunction and ce... [J Neurol Sci. 2005] - PubMed result - 0 views

  • There is significant evidence that the pathogenesis of several neurodegenerative diseases, including Parkinson's disease, Alzheimer's disease, Friedreich's ataxia (FRDA), multiple sclerosis and amyotrophic lateral sclerosis, may involve the generation of reactive oxygen species (ROS) and/or reactive nitrogen species (RNS) associated with mitochondrial dysfunction
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    Mitochondrial dysfunction at heart of diseases such as Parkinson's, Alzheimers, MS, ALS..
Nathan Goodyear

Implications of free radicals and antioxidant levels in carcinoma of the breast: A neve... - 0 views

  • Experimental investigations as well as clinical and epidemiological findings have provided evidence supporting the role of reactive oxygen metabolites or free radicals such as singlet oxygen O 2 - , superoxide anions (O 2 ), hydrogen peroxide (H­2 O2 ) and hydroxyl radical in the etiology of cancer.
  • Certain aldehydes such as Malonyldialdehyde (MDA), the end product of lipid peroxidation arising from free radical degeneration of polyunsaturated fatty acids can cause cross linking in lipids, proteins and nucleic acids leading to cellular damage.
  • In this study, patients with cancer exhibited higher levels of MDA, both in tissues and serum (p<0.001) compared to the control group [Table 1]. In tissue, the MDA level in stage IV was significantly higher as compared to stage I indicating increased free radical activity with increasing severity of cancer
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  • From these observations, it can be concluded that MDA levels play an important role in assessing the outcome of cancer
  • SOD and CAT are considered primary antioxidant enzymes, since they are involved in direct elimination of reactive oxygen metabolites. [13-16] They also act as anti-carcinogens and inhibitors at initiation and promotion/transformation stage in carcinogenesis
  • In our study, SOD and CAT levels were found to be low in all cancer patients as compared to controls
  • Fridovich and Tayarani have demonstrated in their respective studies that the reduction in SOD activity increases the toxic effects of O2 - and this might lead to severe cellular damage.
  • Mehrotra et al. in their study also observed high levels of MDA and low levels of SOD and CAT in patients of cancer cervix which is in sync with our observations.
  • strong evidence regarding the definitive role of free radicals in breast malignancy.
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    This study finds a strong correlation between advancing breast cancer, decreased catalase and SOD with increasing MDA.  The authors of this study conclude this is a key factor in carcinogenesis and not a by-product of cancer.  This flies in the face of traditional medicines fear of antioxidant therapy in cancer.
Nathan Goodyear

Role of Oxidative Stress and the Microenvironment in Breast Cancer Development and Prog... - 0 views

  • oxidative stress leads to HIF-1α accumulation
  • increased levels of hydrogen peroxide in exhaled breath condensate from patients with localized breast malignancy, associated with increased clinical severity
  • Oxidative stress generated by breast cancer cells activates HIF-1α and NFκB in fibroblasts, leading to autophagy and lysosomal degradation of Cav-1
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  • Comparing mitochondrial metabolic activity revealed a difference between stroma and epithelial cells
  • metalloproteinases (MMP) such as MMP-2, MMP-3, and MMP-9 increase extracellular matrix turnover and are themselves activated by oxidative stress
  • Overexpression of NOX4 in normal breast epithelial cells results in cellular senescence, resistance to apoptosis, and tumorigenic transformation, as well as increased aggressiveness of breast cancer cells
  • Lowered expression of Cav-1 not only leads to myofibroblast conversion and inflammation but also seems to impact aerobic glycolysis, leading to secretion of high energy metabolites such as pyruvate and lactate that drive mitochondrial oxidative phosphorylation in cancer cells
  • Reverse Warburg Effect
  • secreted transforming growth factor β (TGFβ), insulin-like growth factor (IGF), platelet-derived growth factor (PDGF), fibroblast growth factor 2, and stromal-derived factor 1 (SDF1) are able to activate fibroblasts and increase cancer cell proliferation
  • oxidative stress has an important role in the initiation and preservation of breast cancer progression
  • cancer preventive role of healthy mitochondria
  • the cancer cells produce hydrogen peroxide and by driving the “Reverse Warburg Effect” initiate oxidative stress in fibroblasts. As a result of this process, fibroblasts exhibited reduced mitochondrial activity, increased glucose uptake, ROS, and metabolite production.
  • Oxidative stress results from an imbalance between unstable reactive species lacking one or more unpaired electrons (superoxide anion, hydrogen peroxide, hydroxyl radical, reactive nitrogen species) and antioxidants
  • cancer cells are able to induce drivers of oxidative stress, autophagy and mitophagy: HIF-1α and NFκB in surrounding stroma fibro-blasts
  • Studies show that loss of Cav-1 in adjacent breast cancer stroma fibroblasts can be prevented by treatment with N-acetyl cysteine, quercetin, or metformin
  • However, diets rich in antioxidants have fallen short in sufficiently preventing cancer
  • obstructing oxidative stress in the tumor microenvironment can lead to mitophagy and promote breast cancer shutdown is a promising discovery for the development of future therapeutic interventions.
  • It is widely held that HIF-1α function is dependent upon its location within the tumor microenvironment. It acts as a tumor promoter in CAFs and as a tumor suppressor in cancer cells
  • It was reported that overexpression of recombinant (SOD2) (Trimmer et al., 2011) or injection of SOD, catalase, or their pegylated counterparts can block recurrence and metastasis in mice
  • hydrogen peroxide is one of the main factors that can push fibroblasts and cancer cells into senescence
  • Recent studies show that in the breast cancer microenvironment, oxidative stress causes mitochondrial dysfunction
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    Really fascinating article on tumor signaling. The article points to a complex signaling between cancer cells and stromal fibroblasts that results in myofibroblast transformation that increases the microenvironment favorability of cancer. This article points to oxidative stress as the primary driving force.  
Nathan Goodyear

ScienceDirect - 0 views

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    Great review of the redox system in cancer cells. Everybody focus' on the ROS, but forget about the RNS from NO. The current marketing pushes NO for CVD.
Nathan Goodyear

HIF-1-mediated metabolic reprogramming reduces ROS levels and facilitates the metastati... - 0 views

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    HIF-1alpha and ROS relationship in cancer
Nathan Goodyear

Antineoplastic Mechanisms of Niclosamide in Acute Myelogenous Leukemia Stem C... - 0 views

  • Here, we report on niclosamide as an antileukemic agent with two independent antineoplastic mechanisms: NF-κB pathway inactivation and ROS generation
  • In this report, we validated the inhibitory action of niclosamide against tumor necrosis factor (TNF)–induced NF-κB activation in AML cells and identified its mechanism, together with generation of reactive oxygen species (ROS), as being responsible for induced apoptosis of AML cells
  • NF-κB plays a critical role in inflammation, antiapoptotic responses, and carcinogenesis
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  • pharmacologic inhibition of NF-κB was effective in killing AML cells
  • High NF-κB expression is found in primitive human AML blast cells
  • niclosamide inhibited the TNF-induced NF-κB reporter activity in a dose- and time-dependent manner
  • niclosamide inhibiting TNF-induced IKK phosphorylation (Fig. 2A), niclosamide may exert its inhibitory effect at the TAK1 step
  • Pretreatment with niclosamide completely blocked the time- and dose-dependent TNFα-induced alteration of the NF-κB–DNA complex
  • niclosamide inhibited constitutively active NF-κB binding to DNA in U266 cells
  • niclosamide completely abolished the TNFα-induced phosphorylation of IKKα/β and IκBα
  • Accordingly, the TNFα-induced degradation of IκBα was abrogated by niclosamide
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    Old anti-parasitic medication, niclosamide, found to have anti-leukemic acitivty through inactivation of NF-kappaB and increase in ROS production in in Vitro and in Vivo study.
Nathan Goodyear

LTT-MELISA is clinically relevant for detecting and monitoring metal sensitivity. - Pub... - 0 views

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    metal immune reactivity plays a role in disease, particularly inflammatory disease i.e. autoimmune.  This study find benefit from MELISA assays in metal sensitivity treatment.
Nathan Goodyear

Vitamin C increases viral mimicry induced by 5-aza-2′-deoxycytidine | PNAS - 0 views

  • Vitamin C alone at concentrations up to 57 μM had little effect on cell growth but was toxic at 228 μM (SI Appendix, Fig. S1B), in line with recent studies of high vitamin C concentrations (125–2,000 μM)
  • In our combination approach, vitamin C increased the effects of low doses of 5-aza-CdR, with 57 μM vitamin C almost doubling the growth inhibition
  • Using the Chou–Talalay method (28), we found that the two compounds indeed acted synergistically, rather than additively, to inhibit cancer cell growth over the physiological ranges of vitamin C in healthy individuals (26–84 μM)
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  • These results show that targeting the cancer DNA methylome by combining low-dose 5-aza-CdR and vitamin C stimulates the expression of ERVs, the induction of a cell-autonomous immune activation response, and increased apoptosis of cancer cells
  • The addition of vitamin C to treatment protocols therefore may be a straightforward way to increase the clinical efficacy of such drugs in MDS and leukemia patients
  • Vitamin C deficiency has been seen previously in patients with multiple types of cancer, including hematological malignancies (35⇓–37). We predict that these patients might receive the most benefits from the combination treatment.
  • induction of an innate immune response
  • We therefore measured plasma concentrations of vitamin C in a small number of patients with miscellaneous hematologic malignancies. Strikingly, 58% of patients with hematological neoplasia who were not taking vitamin C supplements had severe vitamin C deficiency (serum concentration <11.4 μM, at which clinical features of scurvy may be manifested) (34), and 33% had vitamin C levels below the normal range
  • it is possible that vitamin C was oxidized to DHA before it was transported into the cells
  • Oral administration of vitamin C should be sufficient for the therapeutic strategy, because the concentrations reported in this study would not require i.v. administration.
    • Nathan Goodyear
       
      This statement lacks a basic understanding of vitamin C pharmacokinetics.
  • Vitamin C is an essential nutrient for humans and has been reported to increase IFN levels in human cells upon virus infection
  • daily treatment with vitamin C alone at physiological concentrations enhanced the expression of viral-defense genes relative to untreated cells
  • When combined with low-dose 5-aza-CdR, physiological concentrations of vitamin C synergistically inhibited cancer-cell growth and induced apoptosis. Such synergy was associated with increased ERV expression and dsRNA in treated cells. The mechanism of action differs from that of vitamin C at higher doses, which involves its pro-oxidant activity, including GSH inhibition, to generate reactive oxygen species
  • This activity has been shown to induce DNA damage and to enhance the sensitivities of myeloid malignancies, multiple myeloma, and cutaneous T-cell lymphoma to arsenic trioxide (41⇓⇓–44). It also can increase chemosensitivity of ovarian cancer cells (27) and selectively kill KRAS or BRAF mutant colorectal cancer cells by inhibiting GAPDH
  • reactive oxygen species
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    91% of patients with hematologic malignancies have vitamin C levels that are either low or severly deficient. This study found that vitamin C plus low dose DNA methyltransferase inhibitors have synergistic inhibition of cancer cell proliferation and increased apoptosis.  Unfortunately, the authors claimed that oral vitamin C would be sufficient which indicates an incredible lack of understanding of vitamin C pharmacokinetics.
Nathan Goodyear

The anti-malarial drug artesunate causes cell cycle arrest and apoptosis of triple-nega... - 0 views

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    ART inhibited breast cancer cell proliferation via a reactive oxygen species (ROS)-dependent G2/M arrest and ROS-independent G1 arrest. ART-treated MDA-MB-468 and SK-BR-3 cells also experienced apoptotic cell death, which was both ROS- and iron-dependent. ART-induced oxidative stress caused the loss of mitochondrial outer membrane integrity and damage to the cellular DNA of MDA-MB-468 and SK-BR-3 cells. Only abstract available...I will post full article once available.
Nathan Goodyear

Hyperbaric Oxygen Therapy Can Improve Post Concussion Syndrome Years after Mild Traumat... - 0 views

  • The changes in SPECT images after treatment indicate that HBOT led to reactivation of neuronal activity in stunned areas that seemed normal under CT and MRI imaging. While SPECT imaging has a limited spatial resolution (compared, for example, to fMRI), the changes in activity were sufficiently robust to be clearly detected by the SPECT images.
  • HBOT might initiate a cellular and vascular repair mechanism and improve cerebral vascular flow
  • HBOT induces regeneration of axonal white matter [61], [62], [63], [64], has positive effect upon the myelinization and maturation of injured neural fibers [65], and can stimulate axonal growth and increase the ability of neurons to function and communicate with each other
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  • HBOT was found to have a role in initiation and/or facilitation of angiogenesis and cell proliferation processes needed for axonal regeneration [67].
  • The observed reactivation of neuronal activity in the stunned areas found here, along with similar results in post-stroke patients
  • At the cellular level, HBOT can improve cellular metabolism, reduce apoptosis, alleviate oxidative stress and increase levels of neurotrophins and nitric oxide through enhancement of mitochondrial function (in both neurons and glial cells)
  • HBOT may promote the neurogenesis of endogenous neural stem cells
  • With regard to secondary injury mechanisms in mTBI, HBOT can initiate vascular repair mechanism and improve cerebral vascular flow [58], [59], [68], [69], promote blood brain barrier integrity and reduce inflammatory reactions [28] as well as brain edema
  • It might be possible that HBOT enables the metabolic change simply by supplying the missing energy/oxygen needed for those regeneration processes.
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    Hbot therapy, according to study, induces neuroplasticity and improves brain function in post concussion syndrome and those with mTBI.  The important point about this study was that the study was done years after the injury; what if the therapy was employed immediately after...
Nathan Goodyear

CD40 may be key to activating immune response in pancreatic cancer - 0 views

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    "…it seems most patients who respond do so by reactivation of a previously existing immune response that was perhaps exhausted or subverted by the cancer. If you block these brakes that slow an immune response, you can resume immune activity and achieve a remarkable regression in many cases." "…data shows that CD40 is an important switch for converting a tumor from cold to hot."
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