More than half of cancer patients are treated with IR at some point during their treatment
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shared by Nathan Goodyear on 21 Apr 14
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Triptolide inhibits ovarian cancer cell invasion by repression of matrix metalloprotein... - 0 views
www.ncbi.nlm.nih.gov/...PMC3509180
ovarian cancer triptolide thunder god vine Tripterygium wilfordii matrix metalloproteinase E-cadherin
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shared by Nathan Goodyear on 09 Feb 21
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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
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Nuclear DNA is the primary target of IR; it causes DNA damage (genotoxic stress) by direct DNA ionization
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EMT, stemness, and oncogenic metabolism are known to be associated with resistance to radiotherapy and chemotherapy
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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
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EMT is a developmental process that plays critical roles in embryogenesis, wound healing, and organ fibrosis
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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
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activate EMT-inducing transcription factors, including Snail/Slug, ZEB1/δEF1, ZEB2/SIP1, Twist1/2, and E12/E47
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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
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IR may increase metastasis in both the primary tumour site and in normal tissues under some circumstance
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sublethal doses of IR have been shown to enhance the migratory and invasive behaviours of glioma cells
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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
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Treatment with the N-acetylcysteine (NAC), a general ROS scavenger, prevents IR-induced EMT, adhesive affinity, and invasion of breast cancer cells
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IR activates the p38 MAPK pathway, which contributes to the induction of Snail expression to promote EMT and invasion
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HIF-1 is a heterodimer composed of an oxygen-sensitive α subunit and a constitutively expressed β subunit.
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Under normoxia, HIF-1α is rapidly degraded, whereas hypoxia induces stabilisation and accumulation of HIF-1α
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levels of HIF-1α mRNA are enhanced by activation of the PI3K/Akt/mammalian target of rapamycin (mTOR)
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IR is known to increase stabilisation and nuclear accumulation of HIF-1α, since hypoxia is a major condition for HIF-1 activation
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IR causes the reoxygenation of hypoxic cancer cells to increase ROS production, which leads to the stabilisation and nuclear accumulation of HIF-1
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IR increases glucose availability under reoxygenated conditions that promote HIF-1α translation by activating the Akt/mTOR pathway
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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
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PAI-1 signalling is also implicated in IR-induced Akt activation that increases Snail levels to induce EMT
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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
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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
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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
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Conventional cancer treatments kill most cancer cells, but CSCs survive due to their resistance to therapy, eventually leading to tumour relapse and metastasis
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identification of CSCs, three types of markers are utilised: cell surface molecules, transcription factors, and signalling pathway molecules
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CSCs express distinct and specific surface markers; commonly used ones are CD24, CD34, CD38, CD44, CD90, CD133, and ALDH
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signalling pathways, including those of TGF-β, Wnt, Hedgehog, Notch, platelet-derived growth factor receptor (PDGFR), and JAK/STAT
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EMT-inducing transcription factors, such as Snail, ZEB1, and Twist1, are known to confer CSC properties
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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
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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
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IR has been shown to induce the CSC phenotype in many cancers, including breast, lung, and prostate cancers, as well as melanoma
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Genotoxic stress due to IR or chemotherapy promotes a CSC-like phenotype by increasing ROS production
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In prostate cancer patients, radiotherapy increases the CD44+ cell population that exhibit CSC properties
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IR also induces the re-expression of stem cell regulators, such as Sox2, Oct4, Nanog, and Klf4, to promote stemness in cancer cells
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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
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STAT3 directly binds to the Snail promoter and increases Snail transcription, which induces the EMT and CSC phenotypes, in cisplatin-selected resistant cells
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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
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cancer cells depend on mitochondrial metabolism and increase mitochondrial production of ROS that cause pseudo-hypoxia
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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
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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
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MCT4-positive cancer cells depend on glycolysis and then efflux lactate, while MCT1-positive cells uptake lactate and rely on OXPHOS
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metabolic heterogeneity induces a lactate shuttle between hypoxic/glycolytic cells and oxidative/aerobic tumour cells
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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
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the major fraction of glucose is directed into the pentose phosphate pathway, to produce redox power through the generation of NADPH and ROS scavengers
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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
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HIF-1 induces the expression of glycolytic enzymes, including the glucose transporter GLUT, hexokinase, lactate dehydrogenase (LDH), and MCT, resulting in the glycolytic switch
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HIF-1 represses the expression of pyruvate dehydrogenase kinase (PDK), which inhibits pyruvate dehydrogenase (PDH), thereby inhibiting mitochondrial activity
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pyruvate kinase M2 (PKM2), LDH, and pyruvate carboxylase (PC), are implicated in the induction of the EMT and CSC phenotypes
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IR enhances glycolysis by upregulating GAPDH (a glycolysis enzyme), and it increases lactate production by activating LDHA, which converts pyruvate to lactate
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IR enhances glycolysis by upregulating GAPDH (a glycolysis enzyme), and it increases lactate production by activating LDHA, which converts pyruvate to lactate
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IR also elevates MCT1 expression that exports lactate into the extracellular environment, leading to acidification of the tumour microenvironment
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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
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lactate stimulates cell migration and enhances secretion of hyaluronan from CAF that promote tumour metastasis
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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
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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.
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immunosuppressive cells such as tumour-associated macrophages (TAM), MDSCs, and regulatory T cells, and the immunosuppressive cytokines, TGF-β and interleukin-10 (IL-10)
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immunosuppressive cells such as tumour-associated macrophages (TAM), MDSCs, and regulatory T cells, and the immunosuppressive cytokines, TGF-β and interleukin-10 (IL-10)
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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).
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IR can elicit various changes in the TME, such as CAF activity-mediated ECM remodelling and fibrosis, cycling hypoxia, and an inflammatory response
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IR activates CAFs to promote the release of growth factors and ECM modulators, including TGF-β and MMP
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TGF-β directly influences tumour cells and CAFs, promotes tumour immune escape, and activates HIF-1 signalling
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MMPs degrade ECM that facilitates angiogenesis, tumour cell invasion, and metastasis
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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
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Although IR activates an antitumour immune response, this signalling is frequently suppressed by tumour escape mechanisms
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NETosis and Neutrophil Extracellular Traps in COVID-19: Immunothrombosis and Beyond - PMC - 0 views
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Pneumonia is a typical symptom of COVID-19 infection, while acute respiratory distress syndrome (ARDS) and multiple organ failure are common in severe COVID-19 patients
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SARS-CoV-2 infection has also been linked to increased neutrophil-to-lymphocyte ratios, which is associated with disease severity and clinical prognosis
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NETosis is a special form of programmed cell death in neutrophils, which is characterized by the extrusion of DNA, histones, and antimicrobial proteins in a web-like structure known as neutrophil extracellular traps (NETs)
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increased generation of reactive oxygen species (ROS) is a crucial intracellular process that causes NETosis
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NETs are important for preventing pathogen invasion, their excessive formation can result in a slew of negative consequences, such as autoimmune inflammation and tissue damage
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In COVID-19, major NET protein cargos of NETs (i.e., NE, MPO, and histones) are significantly elevated.
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SARS-CoV-2 can also infect host cells through noncanonical receptors such as C-type lectin receptors
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Immunopathological manifestations, including cytokine storms and impaired adaptive immunity, are the primary drivers behind COVID-19, with neutrophil infiltration being suggested as a significant cause
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NETosis, leading to aberrant immunity such as cytokine storms, autoimmune disorders, and immunosuppression.
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SARS-CoV-2 and its components (e.g., spike proteins and viral RNA) attach to platelets and increase their activation and aggregation in COVID-19, resulting in vascular injury and thrombosis, both of which are linked to NET formation
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early bacterial coinfections were more prevalent in COVID-19 patients than those infected with other viruses
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NETosis and NETs may also have a role in the development of post COVID-19 syndromes, including lung fibrosis, neurological disorders, tumor growth, and worsening of concomitant disease
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NETs and other by-products of NETosis have been shown to act as direct inflammation amplifiers. Hyperinflammation
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SARS-CoV-2 drives NETosis and NET formation to allow for the release of free DNA and by-products (e.g., elastases and histones). This may trigger surrounding macrophages and endothelial cells to secrete excessive proinflammatory cytokines and chemokines, which, in turn, enhance NET formation and form a positive feedback of cytokine storms in COVID-19
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NET release enables self-antigen exposure and autoantibody production, thereby increasing the autoinflammatory response
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patients with COVID-19 who have higher anti-NET antibodies are more likely to be detected with positive autoantibodies [e.g., antinuclear antibodies (ANA) and anti-neutrophil cytoplasmic antibodies (ANCA)]
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can enhance this process by interacting with neutrophils through toll-like receptor 4 (TLR4), platelet factor 4 (PF4), and extracellular vesicle-dependent processes
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have weakened adaptive immunity as well as a high level of inflammation
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tumor-associated NETosis and NETs promote an immunosuppressive environment in which anti-tumor immunity is compromised
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Following initial onset of COVID-19, an estimated 50% or more of COVID-19 survivors may develop multi-organ problems (e.g., pulmonary dysfunction and neurologic impairment) or have worsening concomitant chronic illness
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NETs in the bronchoalveolar lavage fluid of severe COVID-19 patients cause EMT in lung epithelial cells
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decreased E-cadherin (an epithelial marker) expression
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Patients with tumors have been shown to be more vulnerable to SARS-CoV-2 infection and subsequent development of severe COVID-19
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patients who have recovered from COVID-19 may have an increased risk of developing cancer or of cancer progression and metastasis
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vitamin C has been tested in phase 2 clinical trials aimed at reducing COVID-19-associated mortality by reducing excessive activation of the inflammatory response
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vitamin C is an antioxidant that significantly attenuates PMA-induced NETosis in healthy neutrophils by scavenging ROS
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shared by Nathan Goodyear on 27 Jan 14
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The Androgen Derivative 5α-Androstane-3β,17β-Diol Inhibits Prostate Cancer Ce... - 0 views
cancerres.aacrjournals.org/...5445.full
prostate cancer 3-beta androstanediol DHT metabolite E-cadherin ER beta ER-beta male hormone hormones men
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In the early stages, prostate cancer growth is dependent on circulating androgens
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5α-reductase not only provides a potent amplification of the androgenic signal ( 4– 6), but it also prevents estrogen formation by subtracting testosterone from the action of aromatase ( 7, 8), thus blocking activation of the estrogen receptor subtypes (ERα and ERβ; refs. 9, 10)
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ERβ is the prevailing subtype ( 11), and a growing body of evidence points to the protective role of this receptor in prostate cancer
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It has been shown that the transformation of the dihydrotestosterone to 5α-androstane-3α,17β-diol (3α-diol) and 5α-androstane-3β,17β-diol (3β-Adiol), generates two metabolites unable to bind the androgen receptor, but possessing a very high affinity for the estrogen receptors
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the effects of testosterone may result from the balance between the androgenic and the estrogenic molecules originating from its catabolism.
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Recent data have been published postulating a direct estrogenic role of the 3β-hydroxylated derivatives of dihydrotestosterone in the prostate development and homeostasis
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Meta-analysis of Vitamin D Sufficiency for Improving Survival of Patients with Breast C... - 0 views
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Higher serum 25(OH)D concentrations were associated with lower fatality rates in patients with breast cancer
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Patients with the highest concentration of 25(OH)D had approximately half the fatality rate compared to those with the lowest concentration
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According to this hypothesis, the growth of a tumor may be arrested at almost any point in the DINOMIT model by restoring a high serum 25(OH)D concentration in the organism, resulting in up-regulation of E-cadherin and restoration of a well-differentiated state
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Laboratory studies have demonstrated anticancer effects of vitamin D metabolites on three critical phases in the development of breast tumors: differentiation, apoptosis, and angiogenesis
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Epithelial‐to‐mesenchymal transition (EMT) to sarcoma in recurrent lung adeno... - 0 views
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facilitates the dissemination of cancer cells to distant organs. In addition to facilitating metastasis, EMT is thought to generate cancer stem cells (CSCs), which are generally resistant to apoptosis and to standard chemotherapeutic drugs and radiotherapy
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aside from TGF‐β and Snail, several other signalling pathways including Notch, Wnt, and integrin are known to activate EMT through transcriptional repression of E‐cadherin
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increasing evidence that treatment with chemotherapy or chemoradiotherapy can induce EMT in NSCLC which in turn is thought to generate CSCs which are generally resistant to such treatments
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cisplatin has been shown to increase the release of Interleukin‐6 (IL‐6) and expression of transforming growth factor beta (TGF‐β)