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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
  • 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
  • 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
  • aerobic glycolysis takes place in cancer-associated fibroblasts, rather than in tumor cells, as previously suspected.
  • 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 lipoxygenase inhibitor in breast cancer brain metastases | SpringerLink - 0 views

link.springer.com/...s11060-006-9248-4

Boswellia brain metastasis cancer

shared by Nathan Goodyear on 29 Apr 21 - No Cached
  • Nathan Goodyear on 29 Apr 21
     
    Boswellia reduced brain metastasis; in oral delivery of 800 mg TID
Nathan Goodyear

Melanoma Unknown Primary Brain Metastasis Treatment with ECHO-7 Oncolytic Virus Rigvir:... - 0 views

www.ncbi.nlm.nih.gov/...PMC5834433

Cancer RIGVIR immunotherapy

shared by Nathan Goodyear on 19 Oct 18 - No Cached
  • Nathan Goodyear on 19 Oct 18
     
    Case study of the oncolytic therapy RIGVIR for Brain metastasis.
Nathan Goodyear

Digoxin Induced Dissolution of CTC Clusters | Clinical Research Trial Listing ( Breast ... - 0 views

www.centerwatch.com/...ed-dissolution-of-ctc-clusters

circulating tumor cells CTC digoxin metastasis cancer

shared by Nathan Goodyear on 04 May 23 - No Cached
  • Nathan Goodyear on 04 May 23
     
    Digoxin disrupts CTC "clusters". Very interesting.
Nathan Goodyear

Full article: Local recurrence of brain metastasis reduced by intra-operative hyperther... - 0 views

www.tandfonline.com/...02656736.2018.1488004

hyperthermia metastasis recurrence brain cancer local recurrence

shared by Nathan Goodyear on 26 Apr 21 - No Cached
  • Nathan Goodyear on 26 Apr 21
     
    Hyperthermia reduces recurrence risk by 55% of metastatic brain cancer after surgery over conventional therapies.
Nathan Goodyear

Hyperbaric oxygen therapy promotes neurogenesis: where do we stand? - 0 views

www.ncbi.nlm.nih.gov/...PMC3231808

hbot hyperbaric therapy hyperbaric brain TBI stroke neurogenesis neuorplasticity

shared by Nathan Goodyear on 18 May 17 - No Cached
  • Numerous in vivo and in vitro studies confirm that HBOT induces neurogenesis
  • HIF-1α is the principal mediator of cellular hypoxia adaptations
  • activated by hypoxia, HIF-1α causes the transcription of its regulated downstream genes, including erythropoietin (EPO) and VEGF which are known to promote neurogenesis
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  • The safety of HBOT was also evaluated and it was pointed out that, if given at proper paradigms, like 1.5 ATA for 60 minutes, HBOT will not cause oxygen toxicity
  • Rockswold et al., on the other hand, found that HBOT might be potentially beneficial for severe TBI patients
  • McDonagh et al., concluded that there was insufficient evidence to establish the effectiveness of HBOT in the treatment of TBI
  • The first multicenter, randomized, double-blind, controlled trial in 2009 found that 40-hour HBOT of 24% oxygen at 1.3 ATM produced significant improvement in children's overall functioning, receptive language, social interaction, eye contact, and sensory/cognitive awareness compared to those received slightly pressurized room air
  • Another study in 2010 on 16 autism patients, adopting a similar treatment paradigm, showed no effect on a wide array of behavioral evaluations
  • To date, there is little evidence that HBOT causes malignant growth or metastasis. A history of malignancy should therefore not be considered as a contraindication for HBOT
  • HBOT enhances the production of reactive oxygen species (ROS) and causes oxidative stress in body tissues
  • Excessive accumulation of oxidative stress may contribute to neurodegenerative processes and cell death in the brain, as seen in diseases like Alzheimer's disease (AD) and Parkinson's disease (PD)
  • Hormesis
  • process that results in a functional improvement of cellular stress resistance, survival, and longevity in response to sub-lethal levels of stress
  • Nathan Goodyear on 18 May 17
     
    great review of hbot, brain injury, neuroplasticity and neurogenesis.
Nathan Goodyear

Antitumor activity of dichloroacetate on C6 glioma cell: in vitro and in vivo evaluation - 0 views

www.ncbi.nlm.nih.gov/...PMC3601023

cancer DCA

shared by Nathan Goodyear on 12 Nov 14 - No Cached
  • the oral bioavailability of DCA is nearly 100%
  • the oral bioavailability of DCA is almost 100%.
  • DCA can penetrate into the traditional chemotherapy sanctuary sites. Interestingly, it was reported that DCA could penetrate across the BBB,30 exhibiting the potential activity for brain therapy.
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  • Clinical studies of DCA have shown reduced lactate levels
  • It has been reported that DCA activates the PDH by inhibition of PDK in a dose-dependent manner, and results in increased delivery of pyruvate into the mitochondria
  • The antitumor activity of DCA on nonsmall cell lung cancer, breast cancer, glioblastomas, and endometrial and prostate cancer cells has been demonstrated
  • It is well known that many chemotherapeutic agents have a low therapeutic index in brain tumors.
  • The most common metabolic hallmark of cancer cells is their propensity to metabolize glucose to lactic acid at a high rate even in the presence of oxygen
  • Pyruvate dehydrogenase kinase (PDK) is a gate-keeping enzyme that regulates the flux of carbohydrates (pyruvate) into the mitochondria
  • In the presence of activated PDK, pyruvate dehydrogenase (PDH), a critical enzyme that converts pyruvate to acetyl-CoA instead of lactate in glycolysis, is inhibited, limiting the entry of pyruvate into the mitochondria.
  • the level of Hsp70 was significantly decreased
  • DCA can penetrate the BBB
  • It has been reported that DCA treatment resulted in an increase in the proportion of tumor cells in the S phase, showing a decrease in proliferation as well as the induction of apoptosis
  • Heat shock proteins (HSPs) are involved in protein folding, aggregation, transport, and/or stabilization by acting as a molecular chaperone, leading to the inhibition of apoptosis by both caspase-dependent and/or independent pathways
  • HSPs are overexpressed in a wide range of human cancers and are implicated in tumor cell proliferation, differentiation, invasion, and metastasis
  • Considering the fact that high expression of HSPs is essential for cancer survival, the inhibition of HSPs is an important strategy of anticancer therapy.
  • In addition, after 5 years of continued treatment with oral DCA at a dose of 25 mg/kg, the serum DCA levels are only slightly increased compared with the levels after the first several doses, also showing its safety for oral administration at this dose.
  • DCA can enter the circulation rapidly after oral administration and then generate the stimulation of PDH activity generally within minutes.
  • Our in vivo results in tumor tissues indicated that DCA significantly induced ROS production and decreased MMP in tumor tissues
  • The numbers of microvessels in the DCA treatment groups were significantly decreased, suggesting the potential antiangiogenic effect of DCA
  • Under hypoxic conditions, hypoxia-inducible factor (HIF-1α) is activated and induces angiogenesis
  • In addition, HIF-1α can also induce the expression of PDK,48 which can inhibit the activity of PDH
  • The inhibition effect of DCA on HIF-1α would decrease vascular endothelial growth factor and inhibit angiogenesis
  • the antiangiogenic effect in the 25 mg/kg treatment group was lower than that in 75 mg/kg or 125 mg/kg treatment groups
  • In conclusion, DCA induces the apoptosis of C6 cells through the activation of the mitochondrial pathway, arresting the cell cycle of C6 cells in S phase and down-regulating Hsp70 expression.
  • DCA significantly induced the ROS production and decreased the MMP in tumor tissues. Our in vivo antitumor activity results also indicated that DCA has an antiangiogenic effect
  • Nathan Goodyear on 12 Nov 14
     
    DCA as proposed therapy in cancer.
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