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Nathan Goodyear

The HK2 Dependent "Warburg Effect" and Mitochondrial Oxidative Phosphorylation in Cance... - 0 views

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    biochemistry strikes again: hexokinase 2 shown to be key step in cancer proliferation, energy metabolism and mortality. 3BP shown to be a potent glycolytic inhibitor and in animal studies shown to have significant mortality effects on cancer. Also, great review of cancer cell metabolism i.e Warburg effect, Crabtree effect, LDH, PD, PDK...
Nathan Goodyear

Serum lactate dehydrogenase and survival following cancer diagnosis - 0 views

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    LDH found to correlate with overall and cancer-specific mortality.
Nathan Goodyear

Overall survival of cancer patients with serum lactate dehydrogenase greater ... - 0 views

  • catalyzes the interconversion of pyruvate and lactate during glycolysis and gluconeogenesis
  • It has long been known that many human cancers have higher LDH levels than normal tissues
  • It has long been appreciated that LDH is a prognostic factor for survival
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  • The serum level of LDH correlated with tumor burden and was thought to reflect the tumor’s growth and invasive potential
  • the majority of patients with advanced or metastatic disease could be detected to have extremely high serum level of LDH
  • strong evidence to support effective chemotherapy of full dose even in patients with high LDH level
  • LDH is a key enzyme in the process of energy production in cancer cells, it catalyzes the conversion of pyruvate to lactate in hypoxic conditions
  • its function in anaerobic metabolism, cancer cells grow even after their rapid proliferation that leads to low-oxygen conditions in the tumor microenvironment
  • LDH plays an important role in tumor progression and maintenance
  • inhibition of LDH inhibits tumor progression and has been considered for the therapeutic target of cancer energy metabolism
  • LDH levels are increased in response to tissue injury or during disease states
  • LDH could be a marker of tumor burden for advanced cancer patients
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    High LDH, defined as >1,000, found to be maker for very poor overall survival in retrospective study.
Nathan Goodyear

Dichloroacetate (DCA) as a potential metabolic-targeting therapy for cancer - 0 views

  • The generic drug dichloroacetate is an orally available small molecule that, by inhibiting the pyruvate dehydrogenase kinase, increases the flux of pyruvate into the mitochondria, promoting glucose oxidation over glycolysis
  • The most important reason for the poor performance of cancer drugs is the remarkable heterogeneity and adaptability of cancer cells. The molecular characteristics of histologically identical cancers are often dissimilar and molecular heterogeneity frequently exists within a single tumour.
  • Because GO is far more efficient in generating ATP compared with GLY (producing 36 vs 2 ATP per glucose
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  • molecule), cancer cells upregulate glucose receptors and significantly increase glucose uptake in an attempt to ‘catch up
  • early carcinogenesis often occurs in a hypoxic microenvironment, the transformed cells have to rely on anaerobic GLY for energy production.
  • Hypoxia-inducible factor (HIF) is activated in hypoxic conditions
  • evidence suggests that transformation to a glycolytic phenotype offers resistance to apoptosis
  • non-small cell lung cancer, breast cancer and glioblastoma
  • Dichloroacetate activated the pyruvate dehydrogenase, which resulted in increased delivery of pyruvate into the mitochondria
  • DCA increased GO and depolarised the mitochondria, returning the membrane potential towards the levels of the non-cancer cells, without affecting the mitochondria of non-cancerous cells
  • induction of apoptosis by DCA in non-small cell lung cancer, breast cancer and glioblastoma cell lines
  • DCA was shown to induce apoptosis in endometrial (Wong et al, 2008) and prostate (Cao et al, 2008) cancer cells
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    DCA as targeted therapy in cancer.
Nathan Goodyear

Effect of High-Dose Vitamin C Infusion in a Glucose-6-Phosphate Dehydrogenase-Deficient... - 0 views

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    interesting case study
Nathan Goodyear

Stress-induced epinephrine enhances lactate dehydrogenase A and promotes breast cancer ... - 0 views

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    Epinephrine increases LDH-A in breast cancer
Nathan Goodyear

Metabolic adaptations in cancers expressing isocitrate dehydrogenase mutations - Scienc... - 0 views

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    Oncogenic metabolic shift via the 2HG oncometabolite.
Nathan Goodyear

Stress-induced epinephrine enhances lactate dehydrogenase A and promotes breast cancer ... - 0 views

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    Mood, i.e., fear and stress push glycolytic shift and immunosuppression favoring carcinogenesis. Medicine must revisit how it approaches cancer diagnosis and movement forward. Propagation of fear only accelerates cancer progression.
Nathan Goodyear

Metabolic management of brain cancer - 0 views

  • Glutamine is a major metabolic fuel for both brain tumor cells and tumor-associated macrophages (TAMs)
  • the malignant phenotype of brain tumor cells that survive radiotherapy is often greater than that of the cells from the original tumor.
  • Conventional chemotherapy has faired little better than radiation therapy for the long-term management of malignant brain cancer
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  • most conventional radiation and brain cancer chemotherapies can enhance glioma energy metabolism and invasive properties, which would contribute to tumor recurrence and reduced patient survival [34].
  • We contend that all cancer regardless of tissue or cellular origin is a disease of abnormal energy metabolism
  • complex disease phenotypes can be managed through self-organizing networks that display system wide dynamics involving oxidative and non-oxidative (substrate level) phosphorylation
  • As long as brain tumors are provided a physiological environment conducive for their energy needs they will survive; when this environment is restricted or abruptly changed they will either grow slower, growth arrest, or perish [8] and [19]
  • New information also suggests that ketones are toxic to some human tumor cells and that ketones and ketogenic diets might restrict availability of glutamine to tumor cells [68], [69] and [70].
  • The success in dealing with environmental stress and disease is therefore dependent on the integrated action of all cells in the organism
  • Tumor cells survive in hypoxic environments not because they have inherited genes making them more fit or adaptable than normal cells, but because they have damaged mitochondria and have thus acquired the ability to derive energy largely through substrate level phosphorylation
  • Cancer cells survive and multiply only in physiological environments that provide fuels (mostly glucose and glutamine) subserving their requirement for substrate level phosphorylation
  • Integrity of the inner mitochondrial membrane is necessary for ketone body metabolism since β-hydroxybutyrate dehydrogenase, which catalyzes the first step in the metabolism of β-OHB to acetoacetate, interacts with cardiolipin and other phospholipids in the inner membrane
  • the mitochondria of many gliomas and most tumors for that matter are dysfunctional
  • Cardiolipin is essential for efficient oxidative energy production and mitochondrial function
  • Any genetic or environmental alteration in the content or composition of cardiolipin will compromise energy production through oxidative phosphorylation
  • The Crabtree effect involves the inhibition of respiration by high levels of glucose
  • the Warburg effect involves elevated glycolysis from impaired oxidative phosphorylation
  • the Crabtree effect can be reversible, the Warburg effect is largely irreversible because its origin is with permanently damaged mitochondria
  • The continued production of lactic acid in the presence of oxygen is the metabolic hallmark of most cancers and is referred to as aerobic glycolysis or the Warburg effect
  • We recently described how the retrograde signaling system could induce changes in oncogenes and tumor suppressor genes to facilitate tumor cell survival following mitochondrial damage [48].
  • In addition to glycolysis, glutamine can also increase ATP production under hypoxic conditions through substrate level phosphorylation in the TCA cycle after its metabolism to α-ketoglutarate
  • mitochondrial lipid abnormalities, which alter electron transport activities, can account in large part for the Warburg effect
  • targeting both glucose and glutamine metabolism could be effective for managing most cancers including brain cancer
  • The bulk of experimental evidence indicates that mitochondria are dysfunctional in tumors and incapable of generating sufficient ATP through oxidative phosphorylation
  • Cardiolipin defects in tumor cells are also associated with reduced activities of several enzymes of the mitochondrial electron transport chain making it unlikely that tumor cells with cardiolipin abnormalities can generate adequate energy through oxidative phosphorylation
  • The Crabtree effect involves the inhibition of respiration by high levels of glucose
  • Warburg effect involves elevated glycolysis from impaired oxidative phosphorylation
  • TCA cycle substrate level phosphorylation could therefore become another source of ATP production in tumor cells with impairments in oxidative phosphorylation
  • Caloric restriction, which lowers glucose and elevates ketone bodies [63] and [64], improves mitochondrial respiratory function and glutathione redox state in normal cells
  • DR naturally inhibits glycolysis and tumor growth by lowering circulating glucose levels, while at the same time, enhancing the health and vitality of normal cells and tissues through ketone body metabolism
  • DR is anti-angiogenic
  • DR also reduces angiogenesis in prostate and breast cancer
  • We suggest that apoptosis resistance arises largely from enhanced substrate level phosphorylation of tumor cells and to the genes associated with elevated glycolysis and glutaminolysis, e.g., c-Myc, Hif-1a, etc, which inhibit apoptosis
  • Modern medicine has not looked favorably on diet therapies for managing complex diseases especially when well-established procedures for acceptable clinical practice are available, regardless of how ineffective these procedures might be in managing the disease
  • More than 60 years of clinical research indicates that such approaches are largely ineffective in extending survival or improving quality of life
  • The process is rooted in the well-established scientific principle that tumor cells are largely dependent on substrate level phosphorylation for their survival and growth
  • Glucose and glutamine drive substrate level phosphorylation
  • targeting the glycolytically active tumor cells that produce pro-cachexia molecules, restricted diet therapies can potentially reduce tumor cachexia
  • It is important to recognize, however, that “more is not better” with respect to the ketogenic diet
  • Blood glucose ranges between 3.0 and 3.5 mM (55–65 mg/dl) and β-OHB ranges between 4 and 7 mM should be effective for tumor management
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    Dr Seyfriend presents his metabolic approach to the treatment of brain cancer.
Nathan Goodyear

Pre-receptor regulation of the androgen receptor - 0 views

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    Great read on the regulation of the androgen receptor by the different iso forms of 5-alpha reductase and HSD.
Nathan Goodyear

Estrogen receptor β and the progression of prostate cancer: role of 5α-andros... - 0 views

  • In the prostate, ERβ is highly expressed in the epithelial compartment, where it is the prevailing isoform
  • In the gland, DHT may be either reversibly 3α- or irreversibly 3β-hydroxylated by the different 3α- and 3β-hydroxysteroid dehydrogenases respectively (Steckelbroeck et al. 2004); these transformations generate two metabolites respectively 3α-diol and 3β-Adiol, which are both unable to bind the AR. Instead, 3β-Adiol displays a high affinity for ERβ (Kuiper et al. 1998, Nilsson et al. 2001), and it has been proposed that this metabolite may play a key role in prostate development
  • ERβ signaling, in contrast to ERα, seems to act as a suppressor of prostate growth, and may be positively involved in breast cancer
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  • 3β-Adiol counteracts PC cell proliferation in vitro
  • 3β-Adiol counteracts the biological actions of its androgenic precursors testosterone and DHT
  • functional antagonism of 3β-Adiol appears to be molecularly independent from the activation of the androgenic pathway
  • the action of 3β-Adiol is mediated, at the molecular levels, by the estrogenic pathway.
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    another awesome article dealing with hormone metabolites. Physicians that don't understand metabolites and receptors may be doing more harm than good.   One of the mainstays of the treatment of metastatic prostate disease is androgen deprivation therapy.  This article requires a reassessment of this due to the DHT metabolite 3-beta androstanediol.  This metabolite is produced from DHT production via the enzyme 3beta HSD.  This metabolite binds to ER beta, an estrogen receptor, and inhibits proliferation, migration, promotes adhesion (limits spreading), and stimulates apoptosis.  This is contrast to 3-alpha androstanediol.  Androgen deprivation therapy will decrease 3-beta androstanediol.  This is the likely reason for the increased aggressive prostate cancer found in those men using 5 alpha reductase inhibitors.
Nathan Goodyear

Highly efficient ketone body treatment in multiple acyl-CoA dehydrogenase deficiency-re... - 0 views

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    case study of a young boy with MADD treated with ketones. Significant improvement/resolution after 5 months of therapy with ketone therapy.  There was even improvement in brain MRI.
Nathan Goodyear

Association of Hypertension and Hypokalemia with Cushing's Syndrome Caused by Ectopic A... - 0 views

  • cortisol may act as a mineralocorticoid when in excess, perhaps by saturating the 11β-hydroxysteroid-dehydrogenase (11β-HSD2 enzyme) that inactivates cortisol at the renal tubule
  • high cortisol levels may be the principal cause of hypokalemic alkalosis
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    high cortisol, whether exogenous or endogenous, can have a mineral corticoid effect and resultant low potassium.
Nathan Goodyear

Adrenocortical dysregulation as a major player in insulin resistance and onset of obesity - 0 views

  • acute GC secretion during stress mobilizes peripheral amino acids from muscle as well as fatty acids and glycerol from peripheral fat stores to provide substrates for glucose synthesis by the liver
  • chronically elevated GC levels alter body fat distribution and increase visceral adiposity as well as metabolic abnormalities in a fashion reminiscent of metabolic syndrome
  • This local production may play an important role in the onset of obesity and insulin resistance.
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  • In adipocytes, cortisol inhibits lipid mobilization in the presence of insulin, thus leading to triglyceride accumulation and retention.
  • Since the density of GC receptors is higher in intra-abdominal (visceral) fat than in other fat depots, the activity of cortisol leading to accumulation of fat is accentuated in visceral adipose tissue (24, 158), providing a mechanism by which excessive endogenous or exogenous GC lead to abdominal obesity and IR
  • obese patients generally have normal or subnormal plasma cortisol concentrations
  • This may be explained by an increased intratissular/cellular concentration of cortisol in adipose tissues
  • Intracellular GC may be produced from recycling of GC metabolites such as cortisone in adipose tissues
  • Local GC recycling metabolism is mediated by 11β-hydroxysteroid dehydrogenase enzymes (11β-HSD1 and 11β-HSD2
  • Cortisol also increases 11β-HSD1 expression in human adipocytes
  • In humans, elevated 11β-HSD1 expression in visceral adipose tissue is also associated with obesity
  • even if obese patients generally have normal or subnormal plasma cortisol concentrations (131, 158), triglyceride accumulation in visceral adipose tissue may be due, at least in part, to the local production of GC in insulin- and GC-responsive organs such as adipose tissue, liver, and skeletal muscle
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    another nice article on the dysregulation of cortisol and its role in insulin resistance, metabolic syndrome, and obesity.
Nathan Goodyear

11beta-hydroxysteroid dehydrogenase type 1 an... [Front Horm Res. 2008] - PubMed - NCBI - 0 views

  • Adipose-selective 11beta -HSD1 transgenic mice exhibited elevated intra-adipose and portal, but not systemic corticosterone levels, abdominal obesity, hyperglycaemia, insulin resistance, dyslipidaemia and hypertension
  • transgenic overexpression of 11beta -HSD1 in liver yielded an attenuated metabolic syndrome with mild insulin resistance, dyslipidaemia, hypertension and fatty liver, but not obesity or glucose intolerance
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    11-betaHSD1 expression and effect is site specific.
Nathan Goodyear

Obesity - Abstract of article: 11[beta]-Hydroxysteroid Dehydrogenase 2 Activity Is Elev... - 0 views

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    11-betaHSD type II increased in adipose tissue.  This correlates with insulin sensitivity.
Nathan Goodyear

Aluminum decreases the glutathione regeneration by the inhibition of NADP-isocitrate de... - 0 views

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    Aluminum decreases the regeneration of reduced glutathione, leading to depletion of glutathione.
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