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Nathan Goodyear

Cancer cells metabolically "fertilize" the tumor microenvironment with hydrogen peroxid... - 0 views

www.ncbi.nlm.nih.gov/...PMC3180189

cancer reverse warburg effect warburg effect NF-kapppB HIF-1alpha Cav-1 H2O2

shared by Nathan Goodyear on 12 Nov 14 - No Cached
  • reducing oxidative stress with powerful antioxidants, is an important strategy for cancer prevention, as it would suppress one of the key early initiating steps where DNA damage and tumor-stroma metabolic-coupling begins. This would prevent cancer cells from acting as metabolic “parasites
  • Oxidative stress in cancer-associated fibroblasts triggers autophagy and mitophagy, resulting in compartmentalized cellular catabolism, loss of mitochondrial function, and the onset of aerobic glycolysis, in the tumor stroma. As such, cancer-associated fibroblasts produce high-energy nutrients (such as lactate and ketones) that fuel mitochondrial biogenesis and oxidative metabolism in cancer cells. We have termed this new energy-transfer mechanism the “reverse Warburg effect.
  • Then, oxidative stress, in cancer-associated fibroblasts, triggers the activation of two main transcription factors, NFκB and HIF-1α, leading to the onset of inflammation, autophagy, mitophagy and aerobic glycolysis in the tumor microenvironment
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  • oxidative stress and ROS, produced in cancer-associated fibroblasts, has a “bystander effect” on adjacent cancer cells, leading to DNA damage, genomic instability and aneuploidy, which appears to be driving tumor-stroma co-evolution
  • tumor cells produce and secrete hydrogen peroxide, thereby “fertilizing” the tumor microenvironment and driving the “reverse Warburg effect.”
  • This type of stromal metabolism then produces high-energy nutrients (lactate, ketones and glutamine), as well as recycled chemical building blocks (nucleotides, amino acids, fatty acids), to literally “feed” cancer cells
  • loss of stromal caveolin (Cav-1) is sufficient to drive mitochondrial dysfunction with increased glucose uptake in fibroblasts, mimicking the glycolytic phenotype of cancer-associated fibroblasts.
  • oxidative stress initiated in tumor cells is transferred to cancer-associated fibroblasts.
  • Then, cancer-associated fibroblasts show quantitative reductions in mitochondrial activity and compensatory increases in glucose uptake, as well as high ROS production
  • These findings may explain the prognostic value of a loss of stromal Cav-1 as a marker of a “lethal” tumor microenvironment
  • aerobic glycolysis takes place in cancer-associated fibroblasts, rather than in tumor cells, as previously suspected.
  • our results may also explain the “field effect” in cancer biology,5 as hydrogen peroxide secreted by cancer cells, and the propagation of ROS production, from cancer cells to fibroblasts, would create an increasing “mutagenic field” of ROS production, due to the resulting DNA damage
  • Interruption of this process, by addition of catalase (an enzyme that detoxifies hydrogen peroxide) to the tissue culture media, blocks ROS activity in cancer cells and leads to apoptotic cell death in cancer cells
  • In this new paradigm, cancer cells induce oxidative stress in neighboring cancer-associated fibroblasts
  • cancer-associated fibroblasts have the largest increases in glucose uptake
  • cancer cells secrete hydrogen peroxide, which induces ROS production in cancer-associated fibroblasts
  • Then, oxidative stress in cancer-associated fibroblast leads to decreases in functional mitochondrial activity, and a corresponding increase in glucose uptake, to fuel aerobic glycolysis
  • cancer cells show significant increases in mitochondrial activity, and decreases in glucose uptake
  • fibroblasts and cancer cells in co-culture become metabolically coupled, resulting in the development of a “symbiotic” or “parasitic” relationship.
  • cancer-associated fibroblasts undergo aerobic glycolysis (producing lactate), while cancer cells use oxidative mitochondrial metabolism.
  • We have previously shown that oxidative stress in cancer-associated fibroblasts drives a loss of stromal Cav-1, due to its destruction via autophagy/lysosomal degradation
  • a loss of stromal Cav-1 is sufficient to induce further oxidative stress, DNA damage and autophagy, essentially mimicking pseudo-hypoxia and driving mitochondrial dysfunction
  • loss of stromal Cav-1 is a powerful biomarker for identifying breast cancer patients with early tumor recurrence, lymph-node metastasis, drug-resistance and poor clinical outcome
  • this type of metabolism (aerobic glycolysis and autophagy in the tumor stroma) is characteristic of a lethal tumor micro-environment, as it fuels anabolic growth in cancer cells, via the production of high-energy nutrients (such as lactate, ketones and glutamine) and other chemical building blocks
  • the upstream tumor-initiating event appears to be the secretion of hydrogen peroxide
  • one such enzymatically-active protein anti-oxidant that may be of therapeutic use is catalase, as it detoxifies hydrogen peroxide to water
  • numerous studies show that “catalase therapy” in pre-clinical animal models is indeed sufficient to almost completely block tumor recurrence and metastasis
  • by eliminating oxidative stress in cancer cells and the tumor microenvironment,55 we may be able to effectively cut off the tumor's fuel supply, by blocking stromal autophagy and aerobic glycolysis
  • breast cancer patients show systemic evidence of increased oxidative stress and a decreased anti-oxidant defense, which increases with aging and tumor progression.68–70 Chemotherapy and radiation therapy then promote further oxidative stress.69 Unfortunately, “sub-lethal” doses of oxidative stress during cancer therapy may contribute to tumor recurrence and metastasis, via the activation of myofibroblasts.
  • a loss of stromal Cav-1 is associated with the increased expression of gene profiles associated with normal aging, oxidative stress, DNA damage, HIF1/hypoxia, NFκB/inflammation, glycolysis and mitochondrial dysfunction
  • cancer-associated fibroblasts show the largest increases in glucose uptake, while cancer cells show corresponding decreases in glucose uptake, under identical co-culture conditions
  • Thus, increased PET glucose avidity may actually be a surrogate marker for a loss of stromal Cav-1 in human tumors, allowing the rapid detection of a lethal tumor microenvironment.
  • it appears that astrocytes are actually the cell type responsible for the glucose avidity.
  • In the brain, astrocytes are glycolytic and undergo aerobic glycolysis. Thus, astrocytes take up and metabolically process glucose to lactate.7
  • Then, lactate is secreted via a mono-carboxylate transporter, namely MCT4. As a consequence, neurons use lactate as their preferred energy substrate
  • both astrocytes and cancer-associated fibroblasts express MCT4 (which extrudes lactate) and MCT4 is upregulated by oxidative stress in stromal fibroblasts.34
  • In accordance with the idea that cancer-associated fibroblasts take up the bulk of glucose, PET glucose avidity is also now routinely used to measure the extent of fibrosis in a number of human diseases, including interstitial pulmonary fibrosis, postsurgical scars, keloids, arthritis and a variety of collagen-vascular diseases.
  • PET glucose avidity and elevated serum inflammatory markers both correlate with poor prognosis in breast cancers.
  • PET signal over-estimates the actual anatomical size of the tumor, consistent with the idea that PET glucose avidity is really measuring fibrosis and inflammation in the tumor microenvironment.
  • human breast and lung cancer patients can be positively identified by examining their exhaled breath for the presence of hydrogen peroxide.
  • tumor cell production of hydrogen peroxide drives NFκB-activation in adjacent normal cells in culture6 and during metastasis,103 directly implicating the use of antioxidants, NFκB-inhibitors and anti-inflammatory agents, in the treatment of aggressive human cancers.
  • Nathan Goodyear on 12 Nov 14
     
    Good description of the communication between cancer cells and fibroblasts.  This theory is termed the "reverse Warburg effect".
Nathan Goodyear

A Randomized Phase II Preoperative Study of Autophagy Inhibition With High-Dose Hydroxy... - 0 views

www.ncbi.nlm.nih.gov/...PMC8086597

immunomodulation hydroxychloroquine pancreatic cancer autophagy inhibitor

shared by Nathan Goodyear on 03 May 21 - No Cached
  • Nathan Goodyear on 03 May 21
     
    Preoperative hydroxychloroquine shows benefit as autophagy inhibitor in conjunction with surgery and chemotherapy
Nathan Goodyear

Chloroquine Inhibits Autophagy to Potentiate Antiestrogen Responsiveness in ER+ Breast ... - 0 views

clincancerres.aacrjournals.org/...3222.abstract

autophagy inhibitor breast cancer hydroxychloroquine cancer ER+

shared by Nathan Goodyear on 03 May 21 - No Cached
  • Nathan Goodyear on 03 May 21
     
    HCQ restores anti estrogen therapy in ER+ breast cancer.
Nathan Goodyear

Repurposing Drugs in Oncology (ReDO)-chloroquine and hydroxychloroquine as anti-cancer ... - 0 views

www.ncbi.nlm.nih.gov/...PMC5718030

chloroquine hydroxychloroquine cancer repurposed drugs

shared by Nathan Goodyear on 03 May 21 - No Cached
  • HCQ, doses for long-term use range between 200 and 400 mg per day.
  • Short-term administration of CQ or HCQ rarely causes severe side effects
  • Short-term administration of CQ or HCQ rarely causes severe side effects
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  • bone marrow suppression
  • cardiomyopathy
  • irreversible retinal toxicity
  • hypoglycaemia
  • daily doses up to 400 mg of HCQ or 250 mg CQ for several years are considered to carry an acceptable risk for CQ-induced retinopathies, with the exception of individuals of short stature
  • chronic CQ or HCQ therapy be monitored through regular ophthalmic examinations (3–6 month intervals), full blood counts and blood glucose level checks
  • long-term HCQ exposure, skeletal muscle function and tendon reflexes should be monitored for weakness
  • both CQ and HCQ, specific caution is advised in patients suffering from impaired hepatic function (especially when associated with cirrhosis), porphyria, renal disease, epilepsy, psoriasis, glucose-6-phosphate dehydrogenase deficiency and known hypersensitivity to 4-aminoquinoline compounds
  • CQ and HCQ can effectively increase the efficacy of various anti-cancer drugs
  • CQ can prevent the entrapment of protonated chemotherapeutic drugs by buffering the extracellular tumour environment and intracellular acidic spaces
  • This study recommends an adjuvant HCQ dose of 600 mg, twice daily.
  • HCQ addition was shown to produce metabolic stress in the tumours
  • HCQ (400 mg/day)
  • important effects of CQ and HCQ on the tumour microenvironment
  • The main and most studied anti-cancer effect of CQ and HCQ is the inhibition of autophagy
  • the expression levels of TLR9 are higher in hepatocellular carcinoma, oesophageal, lung, breast, gastric and prostate cancer cells as compared with adjacent noncancerous cells, and high expression is often linked with poor prognosis
  • TLR9-mediated activation of the NF-κB signalling pathway and the associated enhanced expression of matrix metalloproteinase-2 (MMP-2), MMP-7 and cyclo-oxygenase 2 mRNA
  • HCQ can activate caspase-3 and modulate the Bcl-2/Bax ratio inducing apoptosis in CLL, B-cell CLL and glioblastoma cells
  • In triple-negative breast cancer, CQ was shown to eliminate cancer stem cells through reduction of the expression of Janus-activated kinase 2 and DNA methyl transferase 1 [106] or through induction of mitochondrial dysfunction, subsequently causing oxidative DNA damage and impaired repair of double-stranded DNA breaks
  • CQ or HCQ would be considered for use in combination with immunomodulation anti-cancer therapies
  • Therapies used in combination with CQ or HCQ include chemotherapeutic drugs, tyrosine kinase inhibitors, various monoclonal antibodies, hormone therapies and radiotherapy
  • Most studies hypothesise that CQ and HCQ could increase the efficacy of other anti-cancer drugs by blocking pro-survival autophagy.
  • daily doses between 400 and 1200 mg for HCQ are safe and well tolerated, but two studies identified 600-mg HCQ daily as the MTD
  • HCQ is often administered twice daily to limit plasma fluctuations and toxicity
Nathan Goodyear

Drug Screening Identifies Niclosamide as an Inhibitor of Breast Cancer Stem-Like Cells - 0 views

journals.plos.org/...article

Niclosamide cancer cancer stem cells breast cancer

shared by Nathan Goodyear on 21 Mar 18 - No Cached
  • cancer stem cells may also contribute to tumor formation, metastasis, and treatment resistance
  • Studies have shown that some agents (such as metformin) can selectively target cancer stem cells and that dietary polyphenols, curcumin, peperine, and sulforaphane, which are derived from broccoli/broccoli sprouts, are able to target breast cancer stem cells via inhibition of the Wnt signaling, which affects mammosphere size and colony formation
  • niclosamide inhibits tumor growth and reduces tumor weight
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  • Niclosamide treatment inhibited the expression of cyclin D1, Hes1, and PTCH by 33%, 57%, and 79%, respectively
  • The mechanism via which niclosamide, a protonophoric anthelmintic drug, induces stem-like-cell-specific toxicity in breast cancer is interesting. It is an old drug that has been used to treat tapeworms in animals
  • Niclosamide is known to uncouple mitochondrial oxidative phosphorylation during tapeworm killing
  • A screening of autophagy modulators revealed that niclosamide is a novel inhibitor of mTORC1 signaling
  • A recent work also demonstrated that niclosamide induces the apoptosis of myelogenous leukemic cells via the inactivation of NF-kappaB and reactive oxygen species generation
  • Niclosamide was also reported to inhibit Wnt signaling [31]–[33] in colon cancer cells
  • Our recent work demonstrated that niclosamide disrupts multiple metabolic pathways in ovarian-cancer-initiating cells
  • The present study showed that niclosamide treatment resulted in the downregulation of target genes involved in the self-renewal of cancer stem-like cells and inhibited breast SPS
  • Nathan Goodyear on 21 Mar 18
     
    Old ant-parasitic, niclosamide, found to down-regulate cancer stem cell activity.
Nathan Goodyear

Niclosamide, an old antihelminthic agent, demonstrates antitumor activity by blocking m... - 0 views

www.ncbi.nlm.nih.gov/...PMC3777479

Niclosamide cancer NF-kappaB Wnt ROS mTOR

shared by Nathan Goodyear on 16 Apr 18 - No Cached
  • Accumulating evidence suggests that niclosamide targets multiple signaling pathways such as nuclear factor-kappaB (NF-kB), Wnt/β-catenin, and Notch, most of which are closely involved with cancer stem cell proliferation
  • The transcription factor NF-κB has been demonstrated to promote cancer growth, angiogenesis, escape from apoptosis, and tumorigenesis
  • NF-κB is sequestered in the cytosol of resting cells through binding the inhibitory subunit IκBα
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  • Niclosamide blocked TNFα-induced IκBα phosphorylation, translocation of p65, and the expression of NF-κB-regulated genes
  • Niclosamide also inhibited the DNA binding of NF-κB to the promoter of its target genes
  • niclosamide has two independent effects: NF-kB activation and ROS elevation
  • The Wnt signaling pathway plays fundamental roles in directing tissue patterning in embryonic development, in maintaining tissue homeostasis in differentiated tissue, and in tumorigenesis
  • niclosamide is a potent inhibitor of the Wnt/β-catenin pathway
  • The Notch signaling pathway plays important roles in a variety of cellular processes such as proliferation, differentiation, apoptosis, cell fate decisions, and maintenance of stem cells
  • niclosamide potently suppresses the luciferase activity of a CBF-1-dependent reporter gene in both a dose-dependent and a time-dependent manners in K562 leukemia cells
  • niclosamide treatment abrogated the epidermal growth factor (EGF)-stimulated dimerization and nuclear translocation and transcriptional activity of Stat3, and induced cell growth inhibition and apoptosis in several types of cancer cells (e.g. Du145, Hela, A549) that exhibit relatively higher levels of Stat3 constitutive activation
  • niclosamide can rapidly increase autophagosome formation
  • niclosamide induced autophagy and inhibited mammalian target of rapamycin complex 1 (mTORC1)
  • Niclosamide has low toxicity in mammals (oral median lethal dose in rats >5000 mg/kg
  • Niclosamide is active against cancer cells such as AML and colorectal cancer cells, not only as a monotherapy but also as part of combination therapy, in which it has been found to be synergistic with frontline chemotherapeutic agents (e.g., oxaliplatin, cytarabine, etoposide, and daunorubicin)
  • Because niclosamide targets multiple signaling pathways (e.g., NF-κB, Wnt/β-catenin, and Notch), most of which are closely involved with cancer stem cells, it holds promise in eradicating cancer stem cells
  • Nathan Goodyear on 16 Apr 18
     
    Review article: common anti-parasitic medication, niclosamide, provides anti-proliferative effect in cancer stem cells (CSC), via inhibition of NF-kappaBeta, Wnt/B-catenin, Notch, ROS, mTORC1, and STAT2 pathways.
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