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Promising role for Gc-MAF in cancer immunotherapy: from bench to bedside - 0 views

www.ncbi.nlm.nih.gov/...PMC5686300 nagalase Gc-MAF cancer
shared by Nathan Goodyear on 29 Jan 18 - No Cached
  • MAF precursor activity has also been lost or reduced after Gc-globulin treatment in some cancer cell lines
  • This appears to result from the deglycosylated ɑ-N-acetylgalactosaminidase (nagalase) secreted from cancerous cells
  • Nagalase has been detected in many cancer patients, but not in healthy individuals
  • ...31 more annotations...
  • Studies have shown that the production of nagalase has a mutual relationship with Gc-MAF level and immunosuppression
  • It has been demonstrated that serum levels of nagalase are good prognosticators of some types of cancer
  • The nagalase level in serum correlates with tumor burden and it has been shown that Gc-MAF therapy progresses, nagalase activity decreases
  • It has been shown that Gc-MAF can inhibit the angiogenesis induced by pro-inflammatory prostaglandin E1
  • The effect of Gc-MAF on chemotaxis or activation of tumoricidal macrophages is likely the main mechanism against angiogenesis.
  • Administration of Gc-MAF stimulates immune-cell progenitors for extensive mitogenesis, activates macrophages and produces antibodies. “This indicates that Gc-MAF is a powerful adjuvant for immunization.”
  • Cancer cell lines do not develop into tumor genes in mouse models after Gc-MAF-primed immunization (29-31) and the effect of Gc-MAF has been approved for macrophage stimulation for angiogenesis, proliferation, migration and metastatic inhibition on tumors induced by MCF-7 human breast cancer cell line
  • The protocol included: "a high dose of second-generation Gc-MAF (0.5 ml) administered twice a week intramuscularly for a total of 21 injections.”
  • Yamamoto et al. showed that the administration of Gc-MAF to 16 patients with prostate cancer led to improvements in all patients without recurrence
  • Inui et al. reported that a 74-year-old man diagnosed with prostate cancer with multiple bone metastases was in complete remission nine months after initiation of GcMAF therapy simultaneously with hyper T/NK cell, high-dose vitamin C and alpha lipoic acid therapy
  • It has also been approved for non-neoplastic diseases such as autism (41), multiple sclerosis (42, 43), chronic fatigue syndrome (CFS) (40), juvenile osteoporosis (44) and systemic lupus erythematous (45).
  • Gc-MAF has been verified for use in colon, thyroid (38), lung (39), liver, thymus (36), pancreatic (40), bladder and ovarian cancer and tongue squamous carcinoma
  • Prostate, breast, colon, liver, stomach, lung (including mesothelioma), kidney, bladder, uterus, ovarian, head/neck and brain cancers, fibrosarcomas and melanomas are the types of cancer tested thus far
  • weekly administration of 100 ng Gc-MAF to cancer at different stages and types showed curative effects at different follow-up times
  • this treatment has been suggested for non-anemic patients
  • Studies have shown that weekly administration of 100 ng Gc-MAF to cancer patients had curative effects on a variety of cancers
  • Because the half-life of the activated macrophages is approximately one week, it must be administered weekly
  • In vivo weekly intramuscular administration of Gc-MAF (100 ng) for 16-22 weeks was used to treat patients with breast cancer
  • individuals harboring different VDR genotypes had different responses to Gc-MAF and that some genotypes were more responsive than others
  • Administration of Gc-MAF for cancer patients exclusively activates macrophages as an important cell in adaptive immunity
  • Gc-MAF supports humoral immunity by producing, developing and releasing large quantities of antibodies against cancer. Clinical evidence from a human model of breast cancer patients supports this hypothesis
  • There is also evidence that confirms the tumoricidal role of Gc-MAF via Fc-receptor mediation
  • It is likely that the best therapeutic responses will be observed when the nutritional and inflammatory aspects are taken together with stimulation of the immune system
  • it should be noted that no harmful side effects of Gc-MAF treatment have been reported, even when it was successfully administered to autistic children
  • The natural activation mechanism of macrophages by Gc-MAF is so natural and it should not have any side effects on humans or animal models even in cell culture
  • Besides the Gc-MAF efficacy on macrophage activity, it can be a potential anti-angiogenic agent (28) and an inhibitor of the migration of cancerous cells in the absence of macrophages (47).
  • Activating or modifying natural killer cells, dendritic cells, DC, CTL, INF and IL-2 have all been recommended for cancer immunotherapy
  • It has been reported that nagalase cannot deglycosylate Gc-MAF as it has specificity for Gc globulin alone
  • inflammation-derived macrophage activation with the participation of B and T lymphocytes is the main mechanism
  • macrophages highly-activated by the addition of Gc-MAF can show tumoricidal activity
  • Previous clinical investigations have confirmed the efficacy of Gc-MAF. In addition to activating existing macrophages, Gc-MAF is a potent mitogenic factor that can stimulate the myeloid progenitor cells to increase systemic macrophage cell counts by 40-fold in four days
  • Nathan Goodyear on 29 Jan 18
     
    great review on Gc-MAF in cancer.  An increase in nagalase blocks Gc-protein to Gc-MAF activity leaving the host immune system compromised.
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Learn The Pathology Of Premature Ejaculation In Young People - Men's Health Viet Nam - 1 views

menhealth.vn/...xuat-tinh-som hormones cancer Testosterone hormone Men health healthy Premature Ejaculation
shared by trungtamnamkhoa on 25 Jun 19 - No Cached
  • trungtamnamkhoa on 25 Jun 19
     
    This situation of "not going to the market has run out of money" is also a complaint that most doctors in Nam Khoa listen to from patients. If from the beginning, sexual and sexual attractions were simply a kind of human instinct, through which the race would be passed on to the next generation, today with development. The prosperity of human society, sex is also a joy, a happiness and sometimes also a powerful demonstration of love for couples. Because of that, the strategy of "beating fast and fast" which is an advantage in the past has become a difficult obstacle for the heart of the foolish love. Let's find out how to overcome "the market has not run out of money" by the article Premature ejaculation cause and treatment - Men Health!
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The development, retention and decay rates of strength and power in elite rugby union, ... - 0 views

www.ncbi.nlm.nih.gov/...23529287 exercise resistance training weight lifting training
shared by Nathan Goodyear on 30 Nov 17 - No Cached
  • Nathan Goodyear on 30 Nov 17
     
    Study finds 2-4 resistance training episodes per week is optimal.   Strength increased across the 3 time groups evaluated.  The presence of inflammation is key in the interval between and # of workouts per week.  Study found a point of plateau and diminishing returns.
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Frontiers | Microbiome-Derived Lipopolysaccharide Enriched in the Perinuclear Region of... - 0 views

journal.frontiersin.org/...full LPS lipopolysaccharides Alzheimer's disease brain inflammation
shared by Nathan Goodyear on 23 Sep 17 - No Cached
  • lipopolysaccharides (LPS), either alone or in combination, have indicated that when compared, bacterial LPSs exhibit the strongest induction of pro-inflammatory signaling in human neuronal–glial cells in primary coculture of any single inducer, and different LPS extracts from different gastrointestinal (GI)-tract resident Gram-negative bacteria appeared to have different pro-inflammatory potential
  • powerful inducer of the NF-κB
  • In both neocortex and hippocampus, LPS has been detected to range from a ~7- to ~21-fold increase abundance in AD brain
  • ...15 more annotations...
  • Major Gram-negative bacilli of the human GI-tract, such as the abundant B. fragilis and Escherichia coli (E. coli), are capable of discharging a remarkably complex assortment of pro-inflammatory neurotoxins
  • (i) bacterial amyloids (10, 21); (ii) endotoxins and exotoxins (5, 12); (iii) LPS (12, 18); and (iv) small non-coding RNAs (sncRNAs)
  • integral components of the outer leaflet of the outer membrane of Gram-negative bacteria, LPS
  • LPS, the major molecular component of the outer membrane of Gram-negative bacteria normally serves as a physical barrier providing the bacteria protection from its surroundings
  • LPS is also recognized by the immune system as a marker for the detection of bacterial pathogen invasion and responsible for the development of inflammatory response is perhaps the most potent stimulator and trigger of inflammation known
  • AD-affected brains have remarkably large loads of bacterial-derived toxins compared to controls. The transfer of noxious, pro-inflammatory molecules from the GI-tract microbiome to the CNS may be increasingly important during the course of aging when both the GI-tract and blood–brain barriers become significantly more permeable
  • first evidence of a perinuclear association of LPS with AD brain cell nuclei
  • LPS-mediated stimulation of chronic inflammation, beta-amyloid accumulation, and episodic memory decline in murine models of AD (39, 40) and a biophysical association of LPS with amyloid deposits and blood vessels in human AD patients
  • Strong adherence of LPS to the nuclear periphery has recently been shown to inhibit nuclear maturation and function that may impair or block export of mRNA signals from brain cell nuclei, a highly active organelle with extremely high rates of transcription, mRNA processing, and export into the cytoplasm
  • LPS may be further injurious to the nuclear membrane just as LPS contributes to cerebrovascular endothelial cell membrane injury
  • high intake of dietary fiber is a strong inhibitor of B. fragilis abundance and proliferation in the intact human GI-tract and as such is a potent inhibitor of the neurotoxic B. fragilis-derived amyloids, LPS, enterotoxins, and sncRNAs.
  • GI-tract microbiome-derived LPS may be an important initiator and/or significant contributor to inflammatory degeneration in the AD CNS
  • LPS has been recently localized to the same anatomical regions involved in AD-type neuropathology
  • a known pro-inflammatory transcription factor complex that triggers the expression of pathogenic pathways involved in neurodegenerative inflammation
  • pro-inflammatory amyloids, endo- and exotoxins, LPSs, and sncRNAs but also serve as potent sources of membrane-disrupting agents
  • Nathan Goodyear on 23 Sep 17
     
    LPS links gut to inflammation in Alzheimer's disease
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Cross-kingdom inhibition of breast cancer growth by plant miR159 - 0 views

www.ncbi.nlm.nih.gov/...PMC4746606 cancer epigenetics nutrigenomics nutrition diet
shared by Nathan Goodyear on 11 Dec 17 - No Cached
  • MicroRNAs (miRNAs), a major family of small RNAs, are ∼23 nt-long single strands of RNA that bind to mRNA transcripts to inhibit their translation
  • We found that plant miR159 could be detected in human sera and its levels were inversely correlated with BC incidence and progression.
  • The group demonstrates that the plant miRNA miR168 may be taken up through dietary intake to inhibit the expression of its target low-density lipoprotein receptor 1 in the liver21, providing the first evidence that miRNA in food may influence gene expression in mammalian organs.
  • ...6 more annotations...
  • A more recent finding by the same group shows that a plant miRNA from honeysuckle is able to inhibit Influenza A replication22, indicating that plant miRNAs may be useful for treating human diseases.
  • A recent study by Zhang et al. reported that plant-derived miRNAs can be found in human serum.
  • We further identified TCF7 as a mammalian target for miR159 and showed the anti-proliferative function of miR159 in BC cells using in vitro and in vivo models, demonstrating for the first time that a plant miRNA is able to influence BC cell growth.
  • certain dietary miRNAs from plants and other species may serve as highly affordable and powerful means of treatment with minimal inconvenience to patients.
  • miR159 which (using a synthetic mimic) targets TCF7 to inhibit the proliferation of cells whose growth is dependent on TCF7 such as the BC cells MDA-MB-231
  • our study using a BC model clearly indicates the anti-tumor effect of orally administered synthetic miR159 in its naturally existing form with the plant-specific 2'-O-methylation, suggesting the feasibility of using synthetic forms of plant miRNAs as dietary supplements in the treatment of human cancers, including those outside of the GI track
  • Nathan Goodyear on 11 Dec 17
     
    Plant microRNA found to exist in human serum from gut absorption to then alter genetic expression in in-vitro and in vivo studies.
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Oncotarget | NADH autofluorescence, a new metabolic biomarker for cancer stem cells: Id... - 0 views

www.oncotarget.com/index.php vitamin C IV vitamin C cancer cancer stem cells milk thistle silymarin ascorbic acid bee propolis CAPE glycolytic inhibitor natural
shared by Nathan Goodyear on 08 Dec 17 - No Cached
  • Vitamin C was ~10 times more potent than 2-DG for the targeting of CSCs
  • Cancer stem-like cells (CSCs) are thought to be the root cause of chemotherapy-resistance and radio-resistance
  • ultimately leading to treatment failure in patients with advanced disease [1-3]. They have been directly implicated mechanistically in tumor recurrence and metastasis, resulting in poor patient survival
  • ...26 more annotations...
  • mitochondrial biogenesis may be a key driver of the CSC phenotype
  • Our results indicate that increased mitochondrial oxidative stress and high NADH levels are both key characteristics of the CSC metabolic phenotype
  • high levels of NAD(P)H auto-fluorescence are known to be a surrogate marker for mitochondrial “power”, high OXPHOS capacity and increased ATP production
  • CSCs may be strictly dependent on NAD(P)H to maintain their enhanced mitochondrial function
  • an intact NAD+ salvage pathway is strictly required for mammosphere formation, supporting our results using NAD(P)H auto-fluorescence, which enriched CSC activity by more than 5-fold.
  • Since glycolysis is especially critical for maintaining the TCA cycle, OXPHOS and overall mitochondrial function, we next assessed the effects of known glycolytic inhibitors
  • we show that two other natural products that function as effective glycolysis inhibitors, also inhibited mammosphere formation. More specifically, vitamin C (ascorbic acid), which induces oxidative stress and inhibits the activity of GAPDH (a key glycolytic enzyme) [17], also inhibited mammosphere formation, with an IC-50 of 1 mM (Figure 7B). Therefore, vitamin C was ~10 times more potent than 2-DG at targeting CSC propagation
  • silibinin (the major active constituent of silymarin, an extract of milk thistle seeds) [18], which specifically functions as an inhibitor of glucose uptake, blocked mammosphere formation, with an IC-50 between 200 and 400 µM
  • caffeic acid phenyl ester (CAPE), a key component of honey-bee propolis, has potent anti-cancer properties
  • Propolis has a strong history of medicinal use, dating back more than 2,000 years
  • Because of it aromatic ring structure (Figure 8), we speculated that CAPE might function as a potent inhibitor of oxidative mitochondrial metabolism
  • CAPE quantitatively inhibits the mitochondrial oxygen consumption rate (OCR) and, in turn, induces the onset of aerobic glycolysis (ECAR)
  • CAPE shows a clear selectivity for targeting CSCs and adherent cancer cells, relative to normal fibroblasts.
  • CAPE functions as a “natural” mitochondrial OXPHOS inhibitor, that preferentially targets the CSC sub-population. This could explain CAPE’s known anti-cancer properties
  • Our data directly shows that a small fraction of the total cell population, characterized by increased PGC1α activity, high mitochondrial ROS/H2O2 and high NADH levels, has the ability to survive and grow under anchorage-independent conditions, driving mammosphere formation
  • We highlight the utility of certain natural products, such as Silibinin, Vitamin C and CAPE, that could be used to therapeutically target CSCs. Silibinin is the major active component of silymarin, which is an extract prepared from milk thistle seeds.
  • high NADH is a property that is conserved between normal and cancerous stem cells
  • Previous studies have also shown that when non-CSCs and CSCs are both fed mitochondrial fuels (such as L-lactate or ketone bodies), that CSCs quantitatively produce more NADH in response to this stimulus
  • CSCs may be strictly dependent on NADH to maintain their enhanced mitochondrial function
  • The Noble Prize winner, Linus Pauling, was among the first to describe and clinically test the efficacy of Vitamin C, as a relatively non-toxic anti-cancer agent
  • Vitamin C has two mechanisms of action. First, it is a potent pro-oxidant, that actively depletes the reduced glutathione pool, leading to cellular oxidative stress and apoptosis in cancer cells. Moreover, it also behaves as an inhibitor of glycolysis, by targeting the activity of GAPDH, a key glycolytic enzyme.
  • Here, we show that Vitamin C can also be used to target the CSC population, as it is an inhibitor of energy metabolism that feeds into the mitochondrial TCA cycle and OXPHOS
  • Vitamin C may prove to be promising agent for new clinical trials, aimed at testing its ability to reduce CSC activity in cancer patients, as an add-on to more conventional therapies, to prevent tumor recurrence, further disease progression and metastasis
  • Interestingly, a breast cancer based clinical study has already shown that the use of Vitamin C, concurrent with or within 6 months of chemotherapy, significantly reduces both tumor recurrence and patient mortality
  • CAPE quantitatively reduces mitochondrial oxygen consumption (OCR), while inducing a reactive increase in glycolysis (ECAR). As such, it potently inhibits mammosphere formation with an IC-50 of ~2.5 µM. Similarly, it also significantly inhibits cell migration
  • we also demonstrate that 7 different inhibitors of key energetic pathways can be used to effectively block CSC propagation, including three natural products (silibinin, ascorbic acid and CAPE). Future studies will be necessary to test their potential for clinical benefit in cancer patients.
  • Nathan Goodyear on 08 Dec 17
     
    The future of cancer therapy is cancer stem cells.  Study finds that Vitamin C, silymarin, and bee propolis blocks mitochondrial energy pathways in cancer stem cells.  Vitamin C is a known glycolytic inhbitor. Vitamin C was found to inhibit glycolysis via GAPDH targeting to inhibit the energy pathways of the mitochondria in CSCs.  The authors propse that Vitamin C can be used as add on therapies for conventional therapies to specifically attack the CSCs and their contribution to recrurence, treatment resistance, and metastasis potential all in addition to the ability of vitamin C to reduce the side effects of chemotherapy.
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Availability of evidence of benefits on overall survival and quality of life of cancer ... - 0 views

www.bmj.com/bmj.j4530 cancer cancer treatment survival quality of life
shared by Nathan Goodyear on 20 Dec 17 - No Cached
  • Although the goal of cancer treatment is to improve the quantity and quality of life,123 clinical trials designed to gain regulatory approval for new drugs often evaluate indirect or “surrogate” measures of drug efficacy. These endpoints show that an agent has biological activity, but they are not reliable surrogates for improved survival4567891011 or quality of life46111213
  • two recent systematic reviews suggest that the strength of association between surrogates in cancer clinical trials and life extension is generally low
  • Available data from the US show that only a small proportion of cancer treatments approved by the US Food and Drug Administration (FDA) unequivocally show benefits on survival or quality of life.30
  • ...16 more annotations...
  • We sought to systematically evaluate the evidence base for all new drugs and new indications for the treatment of solid tumours and haematological malignancies approved by the EMA in the five year period 2009-13
  • Three investigators (AP, EP, and EG) independently extracted data on and descriptively analysed the following trial features: characteristics of the participant population, study design (randomisation, crossover from experimental to control group, and blinding of investigators and participants), experimental and control groups, enrolment, primary and secondary endpoints, magnitude of benefit on survival and quality of life, and narrative interpretation of the findings
  • Only 18 of the 68 (26%) were supported by a pivotal study powered to evaluate overall survival as the primary outcome
  • From 2009 to 2013, the EMA approved use of 48 oncology drugs
  • Seventeen drugs were approved for treatment of haematological malignancies and 51 for treatment of solid tumours
  • Overall, 72 clinical trials supported the approval of 68 novel drug uses
  • Our scoring was limited to drugs for solid tumours
  • Among 68 cancer drug indications approved by the EMA in the period 2009-13, and with a median of 5.4 years’ follow-up, only 35 (51%) were associated with a significant improvement in survival (26/35) or quality of life (9/35) over existing treatment options, placebo, or as add on treatment
  • Only two of the 26 drugs shown to extend life also showed benefits on quality of life
  • 33 (49%) had not shown any improvement on survival or quality of life
  • This systematic evaluation of oncology drug approvals by the EMA in 2009-13 shows that most of the drugs (39/68, 57%) entered the market without evidence of improved survival or quality of life
  • At a minimum 3.3 years after market entry, there was still no conclusive evidence that 33 of these 39 cancer drugs either extended or improved life
  • What are potential reasons for the paucity of drug approvals with demonstrable survival advantages over existing treatments?
  • Firstly, only 18 (26%) indications for use in our cohort were supported by trials in which extension of life was the primary outcome
  • None of the pivotal studies supporting oncology drug approvals from 2009 to 2013 included quality of life as a primary outcome measure
  • Most new oncology drugs authorised by the EMA in 2009-13 came onto the market without clear evidence that they improved the quality or quantity of patients’ lives
  • Nathan Goodyear on 20 Dec 17
     
    New study from European Medicines Agency questions alot of the new cancer drugs brought to the market 2009-2013.  57% of the new drugs (39/68) were brought to the market without evidence of improved survival or quality of life.
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Induction of metastasis, cancer stem cell phenotype, and oncogenic metabolism in cancer... - 0 views

www.ncbi.nlm.nih.gov/...PMC5282724 EMT TME metastasis cancer stem cells cancer MMP2 Notch MMP-9 MMP-2 radioresistance Hedgehog CSC MMP9 Snail HIF-1alpha tumor microenvironment epithelial to mesenchymal transition TGF-beta radiation
shared by Nathan Goodyear on 09 Feb 21 - No Cached
  • More than half of cancer patients are treated with IR at some point during their treatment
  • fractionation schedule is the delivery of 1.8–2.0 Gy per day, five days per week
  • Nuclear DNA is the primary target of IR; it causes DNA damage (genotoxic stress) by direct DNA ionization
  • ...121 more annotations...
  • IR also indirectly induces DNA damage by stimulating reactive oxygen species (ROS) production
  • IR is known to induce EMT in vitro
  • p53 is activated in response to IR-induced DNA damage
  • IR paradoxically also promotes tumour recurrence and metastasis
  • DNA double-strand breaks (DSBs)
  • cancer cells undergoing EMT acquire invasive and metastatic properties
  • changes in the tumour microenvironment (TME)
  • IR seems to induce EMT and CSC phenotypes by regulating cellular metabolism
  • EMT, stemness, and oncogenic metabolism are known to be associated with resistance to radiotherapy and chemotherapy
  • Hanahan and Weinberg proposed ten hallmarks of cancer that alter cell physiology to enhance malignant growth: 1) sustained proliferation, 2) evasion of growth suppression, 3) cell death resistance, 4) replicative immortality, 5) evasion of immune destruction, 6) tumour-promoting inflammation, 7) activation of invasion and metastasis, 8) induction of angiogenesis, 9) genome instability, and 10) alteration of metabolism
  • EMT is a developmental process that plays critical roles in embryogenesis, wound healing, and organ fibrosis
  • IR is known to induce stemness and metabolic alterations in cancer cells
  • transforming growth factor-β [TGF-β], epidermal growth factor [EGF]) and their associated signalling proteins (Wnt, Notch, Hedgehog, nuclear-factor kappa B [NF-κB], extracellular signal-regulated kinase [ERK], and phosphatidylinositol 3-kinase [PI3K]/Akt
  • activate EMT-inducing transcription factors, including Snail/Slug, ZEB1/δEF1, ZEB2/SIP1, Twist1/2, and E12/E47
  • Loss of E-cadherin is considered a hallmark of EMT
  • IR has been shown to induce EMT to enhance the motility and invasiveness of several cancer cells, including those of breast, lung, and liver cancer, and glioma cells
  • IR may increase metastasis in both the primary tumour site and in normal tissues under some circumstance
  • sublethal doses of IR have been shown to enhance the migratory and invasive behaviours of glioma cells
  • ROS are known to play an important role in IR-induced EMT
  • High levels of ROS trigger cell death by causing irreversible damage to cellular components such as proteins, nucleic acids, and lipids, whereas low levels of ROS have been shown to promote tumour progression—including tumour growth, invasion, and metastasis
  • hypoxia-inducible factor-1 (HIF-1) is involved in IR-induced EMT
  • Treatment with the N-acetylcysteine (NAC), a general ROS scavenger, prevents IR-induced EMT, adhesive affinity, and invasion of breast cancer cells
    • Nathan Goodyear
      Nathan Goodyear on 09 Feb 21
       
      NAC for all patients receiving radiation therapy
  • Snail has been shown to play a crucial role in IR-induced EMT, migration, and invasion
  • IR activates the p38 MAPK pathway, which contributes to the induction of Snail expression to promote EMT and invasion
  • NF-κB signalling that promotes cell migration
  • ROS promote EMT to allow cancer cells to avoid hostile environments
  • HIF-1 is a heterodimer composed of an oxygen-sensitive α subunit and a constitutively expressed β subunit.
  • Under normoxia, HIF-1α is rapidly degraded, whereas hypoxia induces stabilisation and accumulation of HIF-1α
  • levels of HIF-1α mRNA are enhanced by activation of the PI3K/Akt/mammalian target of rapamycin (mTOR)
  • IR is known to increase stabilisation and nuclear accumulation of HIF-1α, since hypoxia is a major condition for HIF-1 activation
  • IR induces vascular damage that causes hypoxia
  • ROS is implicated in IR-induced HIF-1 activation
  • IR causes the reoxygenation of hypoxic cancer cells to increase ROS production, which leads to the stabilisation and nuclear accumulation of HIF-1
  • IR increases glucose availability under reoxygenated conditions that promote HIF-1α translation by activating the Akt/mTOR pathway
  • The stabilised HIF-1α then translocates to the nucleus, dimerizes with HIF-1β, and increases gene expression— including the expression of essential EMT regulators such as Snail—to induce EMT, migration, and invasion
  • TGF-β signalling has been shown to play a crucial role in IR-induced EMT
  • AP-1 transcription factor is involved in IR-induced TGF-β1 expression
  • Wnt/β-catenin signalling is also implicated in IR-induced EMT
  • Notch signalling is known to be involved in IR-induced EMT
  • IR also increases Notch-1 expression [99]. Notch-1 is known to induce EMT by upregulating Snail
  • PAI-1 signalling is also implicated in IR-induced Akt activation that increases Snail levels to induce EMT
  • EGFR activation is known to be associated with IR-induced EMT, cell migration, and invasion by activating two downstream pathways: PI3K/Akt and Raf/MEK/ERK
  • ROS and RNS are also implicated in IR-induced EGFR activation
  • IR has also been shown to activate Hedgehog (Hh) signalling to induce EMT
  • IR has been shown to induce Akt activation through several signalling pathways (EGFR, C-X-C chemokine receptor type 4 [CXCR4]/C-X-C motif chemokine 12 [CXCL12], plasminogen activator inhibitor 1 [PAI-1]) and upstream regulators (Bmi1, PTEN) that promote EMT and invasion
  • CSCs possess a capacity for self-renewal, and they can persistently proliferate to initiate tumours upon serial transplantation, thus enabling them to maintain the whole tumour
  • Conventional cancer treatments kill most cancer cells, but CSCs survive due to their resistance to therapy, eventually leading to tumour relapse and metastasis
  • identification of CSCs, three types of markers are utilised: cell surface molecules, transcription factors, and signalling pathway molecules
  • CSCs express distinct and specific surface markers; commonly used ones are CD24, CD34, CD38, CD44, CD90, CD133, and ALDH
  • Transcription factors, including Oct4, Sox2, Nanog, c-Myc, and Klf4,
  • signalling pathways, including those of TGF-β, Wnt, Hedgehog, Notch, platelet-derived growth factor receptor (PDGFR), and JAK/STAT
  • microRNAs (miRNAs), including let-7, miR-22, miR-34a, miR-128, the miR-200 family, and miR-451
  • Non-CSCs can be reprogrammed to become CSCs by epigenetic and genetic changes
  • EMT-inducing transcription factors, such as Snail, ZEB1, and Twist1, are known to confer CSC properties
  • Signalling pathways involved in EMT, including those of TGF-β, Wnt, and Notch, have been shown to play important roles in inducing the CSC phenotype
  • TGF-β1 not only increases EMT markers (Slug, Twist1, β-catenin, N-cadherin), but also upregulates CSC markers (Oct4, Sox2, Nanog, Klf4) in breast and lung cancer cells
  • some CSC subpopulations arise independently of EMT
  • IR has been shown to induce the CSC phenotype in many cancers, including breast, lung, and prostate cancers, as well as melanoma
  • Genotoxic stress due to IR or chemotherapy promotes a CSC-like phenotype by increasing ROS production
  • IR has been shown to induce reprogramming of differentiated cancer cells into CSCs
  • In prostate cancer patients, radiotherapy increases the CD44+ cell population that exhibit CSC properties
  • IR also induces the re-expression of stem cell regulators, such as Sox2, Oct4, Nanog, and Klf4, to promote stemness in cancer cells
  • EMT-inducing transcription factors and signalling pathways, including Snail, STAT3, Notch signalling, the PI3K/Akt pathway, and the MAPK cascade, have been shown to play important roles in IR-induced CSC properties
  • STAT3 directly binds to the Snail promoter and increases Snail transcription, which induces the EMT and CSC phenotypes, in cisplatin-selected resistant cells
  • Other oncogenic metabolic pathways, including glutamine metabolism, the pentose phosphate pathway (PPP), and synthesis of fatty acids and cholesterol, are also enhanced in many cancers
  • metabolic reprogramming
  • HIF-1α, p53, and c-Myc, are known to contribute to oncogenic metabolism
  • metabolic reprogramming
  • tumour cells exhibit high mitochondrial metabolism as well as aerobic glycolysis
  • occurring within the same tumour
  • CSCs can be highly glycolytic-dependent or oxidative phosphorylation (OXPHOS)-dependen
  • mitochondrial function is crucial for maintaining CSC functionality
  • cancer cells depend on mitochondrial metabolism and increase mitochondrial production of ROS that cause pseudo-hypoxia
  • HIF-1 then enhances glycolysis
  • CAFs have defective mitochondria that lead to the cells exhibiting the Warburg effect; the cells take up glucose, and then secrete lactate to 'feed' adjacent cancer cells
  • lactate transporter, monocarboxylate transporter (MCT)
  • nutrient microenvironment
  • Epithelial cancer cells express MCT1, while CAFs express MCT4. MCT4-positive, hypoxic CAFs secrete lactate by aerobic glycolysis, and MCT1-expressing epithelial cancer cells then uptake and use that lactate as a substrate for the tricarboxylic acid (TCA) cycle
  • MCT4-positive cancer cells depend on glycolysis and then efflux lactate, while MCT1-positive cells uptake lactate and rely on OXPHOS
  • metabolic heterogeneity induces a lactate shuttle between hypoxic/glycolytic cells and oxidative/aerobic tumour cells
  • bulk tumour cells exhibit a glycolytic phenotype, with increased conversion of glucose to lactate (and enhanced lactate efflux through MCT4), CSC subsets depend on oxidative phosphorylation; most of the glucose entering the cells is converted to pyruvate to fuel the TCA cycle and the electron transport chain (ETC), thereby increasing mitochondrial ROS production
  • the major fraction of glucose is directed into the pentose phosphate pathway, to produce redox power through the generation of NADPH and ROS scavengers
  • HIF-1α, p53, and c-Myc, are known to contribute to oncogenic metabolism
  • regulatory molecules involved in EMT and CSCs, including Snail, Dlx-2, HIF-1, STAT3, TGF-β, Wnt, and Akt, are implicated in the metabolic reprogramming of cancer cells
  • HIF-1 induces the expression of glycolytic enzymes, including the glucose transporter GLUT, hexokinase, lactate dehydrogenase (LDH), and MCT, resulting in the glycolytic switch
  • HIF-1 represses the expression of pyruvate dehydrogenase kinase (PDK), which inhibits pyruvate dehydrogenase (PDH), thereby inhibiting mitochondrial activity
  • STAT3 has been implicated in EMT-induced metabolic changes as well
  • TGF-β and Wnt play important roles in the metabolic alteration of cancer cells
  • Akt is also implicated in the glycolytic switch and in promoting cancer cell invasiveness
  • EMT, invasion, metastasis, and stemness
  • pyruvate kinase M2 (PKM2), LDH, and pyruvate carboxylase (PC), are implicated in the induction of the EMT and CSC phenotypes
  • decreased activity of PKM2 is known to promote an overall shift in metabolism to aerobic glycolysis
  • LDH catalyses the bidirectional conversion of lactate to pyruvate
  • High levels of LDHA are positively correlated with the expression of EMT and CSC markers
  • IR has been shown to induce metabolic changes in cancer cells
  • IR enhances glycolysis by upregulating GAPDH (a glycolysis enzyme), and it increases lactate production by activating LDHA, which converts pyruvate to lactate
  • IR enhances glycolysis by upregulating GAPDH (a glycolysis enzyme), and it increases lactate production by activating LDHA, which converts pyruvate to lactate
  • IR also elevates MCT1 expression that exports lactate into the extracellular environment, leading to acidification of the tumour microenvironment
  • IR increases intracellular glucose, glucose 6-phosphate, fructose, and products of pyruvate (lactate and alanine), suggesting a role for IR in the upregulation of cytosolic aerobic glycolysis
  • Lactate can activate latent TGF-
  • lactate stimulates cell migration and enhances secretion of hyaluronan from CAF that promote tumour metastasis
  • promote tumour survival, growth, invasion, and metastasis; enhance the stiffness of the ECM; contribute to angiogenesis; and induce inflammation by releasing several growth factors and cytokines (TGF-β, VEGF, hepatocyte growth factor [HGF], PDGF, and stromal cell-derived factor 1 [SDF1]), as well as MMP
  • tumours recruit the host tissue’s blood vessel network to perform four mechanisms: angiogenesis (formation of new vessels), vasculogenesis (de novo formation of blood vessels from endothelial precursor cells), co-option, and modification of existing vessels within tissues.
  • immunosuppressive cells such as tumour-associated macrophages (TAM), MDSCs, and regulatory T cells, and the immunosuppressive cytokines, TGF-β and interleukin-10 (IL-10)
  • immunosuppressive cells such as tumour-associated macrophages (TAM), MDSCs, and regulatory T cells, and the immunosuppressive cytokines, TGF-β and interleukin-10 (IL-10)
  • intrinsic immunogenicity or induce tolerance
  • cancer immunoediting’
  • three phases: 1) elimination, 2) equilibrium, and 3) escape.
  • The third phase, tumour escape, is mediated by antigen loss, immunosuppressive cells (TAM, MDSCs, and regulatory T cells), and immunosuppressive cytokines (TGF-β and IL-10).
  • IR can elicit various changes in the TME, such as CAF activity-mediated ECM remodelling and fibrosis, cycling hypoxia, and an inflammatory response
  • IR activates CAFs to promote the release of growth factors and ECM modulators, including TGF-β and MMP
  • TGF-β directly influences tumour cells and CAFs, promotes tumour immune escape, and activates HIF-1 signalling
    • Nathan Goodyear
      Nathan Goodyear on 09 Feb 21
       
      And now the receipts
  • MMPs degrade ECM that facilitates angiogenesis, tumour cell invasion, and metastasis
    • Nathan Goodyear
      Nathan Goodyear on 09 Feb 21
       
      Receipts and mechanisms
  • IR also promotes MMP-2/9 activation in cancer cells to promote EMT, invasion, and metastasis
  • IR-induced Snail increases MMP-2 expression to promote EMT
  • Radiotherapy has the paradoxical side-effect of increasing tumour aggressiveness
  • IR promotes ROS production in cancer cells, which may induce the activation of oncogenes and the inactivation of tumour suppressors, which further promote oncogenic metabolism
  • Metabolic alterations
  • oncogenic metabolism
  • elicit various changes in the TME
  • Although IR activates an antitumour immune response, this signalling is frequently suppressed by tumour escape mechanisms
  • Nathan Goodyear on 09 Feb 21
     
    Important review article.
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