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Nathan Goodyear

Progesterone metabolites in breast cancer - 1 views

erc.endocrinology-journals.org/...717.full

progesterone metabolism tumor tumorigenesis cancer risk growth hormone hormones 5-beta-pregnanediol 5-alpha-pregnanediol 4-pregnenediol 5-alpha reductase

shared by Nathan Goodyear on 20 Feb 12 - No Cached
  • P metabolites produced within breast tissues might be independently active hormones functioning as cancer-promoting or -inhibiting regulatory agents
  • these P metabolites function as independent pro-or anti-cancer autocrine/paracrine hormones that regulate cell proliferation, adhesion, apoptosis and cytoskeletal, and other cell status molecules via novel receptors located in the cell membrane and intrinsically linked to cell signaling pathways
  • only a fraction of all breast cancer patients respond to this estrogen-based therapy and the response is only temporary
  • ...30 more annotations...
  • P serves as the precursor for the major steroid hormones (androgens, estrogens, corticosteroids) produced by the gonadal and adrenal cortical tissues.
  • 5α-pregnane, 5β-pregnane, and 4-pregnene metabolites of P
  • These P-metabolizing enzymes included 5α-reductase, 5β-reductase, 3α-hydroxysteroid oxido-reductase (3α-HSO), 3β-HSO, 20α-HSO, 20β-HSO, 6α(β)-, 11β-, 17-, and 21-hydroxylase, and C17–20-lyase
  • Reduction of P to 5α-pregnanes is catalyzed by 5α-reductase and the direct 5α-reduced metabolite of P is 5α-pregnane-3,20-dione (5αP). The 5α-reductase reaction is irreversible
  • The two 4-pregnenes resulting from direct P conversion are 4-pregnen-3α-ol-20-one (3αHP) and 4-pregnen-20α-ol-3-one (20αHP), catalyzed by the actions of 3α-HSO and 20α-HSO respectively
  • the P-metabolizing enzyme activities identified in human breast tissues and cell lines were: 5α-reductase, 3α-HSO, 3β-HSO, 20α-HSO, and 6α-hydroxylase
  • In normal breast tissue, conversion to 4-pregnenes greatly exceeded the conversion to 5α-pregnanes, whereas in tumorous tissue, conversion to 5α-pregnanes greatly exceeded that to 4-pregnenes
  • The results indicated that P 5α-reductase activity is significantly higher, whereas P 3α-HSO and 20α-HSO activities are significantly lower in tumor than in normal tissues
  • he results showed that production of 5α-pregnanes was higher and that of 4-pregnenes was lower in tumorigenic (e.g. MCF-7) than in nontumorigenic (e.g. MCF-10A) cells (Fig. 3c⇑), while differences in ER/P status did not appear to play a role
  • The 5α-pregnane-to-4-pregnene ratios were 7- to 20-fold higher in the tumorigenic than in the nontumorigenic cell lines
  • altered direction in P metabolism, and hence in metabolite ratios, was due to significantly elevated 5α-reductase and depressed 3α- and 20α-HSO activities in breast tumor tissues and tumorigenic cells. It appeared, therefore, that changes in P-metabolizing enzyme activities might be related to the shift toward mammary cell tumorigenicity and neoplasia
  • In vivo, changes in enzyme activity can result from changes in levels of the enzyme due to changes in expression of the mRNA coding for the enzyme, or from changes in the milieu in which the enzyme operates (such as temperature and pH, and concentrations of cofactors, substrates, products, competitors, ions, phospholipids, and other molecules)
  • Overall, the enzyme activity and expression studies strongly suggest that 5α-reductase stimulation and 3α- and 20α-HSO suppression are associated with the transition from normalcy to cancer of the breast
  • The level of expression of 5α-reductase is up-regulated by estradiol and P in the uterus (Minjarez et al. 2001) and by 5α-dihydrotestosterone (DHT) in the prostate
  • 3αHP inhibited whereas 5αP-stimulated proliferation
  • Stimulation in cell numbers was also observed when cells were treated with other 5α-pregnanes, such as 5α-pregnan-3α-ol-20-one, 5α-pregnan-20α-ol-3-one, and 5α-pregnane-3α,20α-diol, whereas other 4-pregnenes such as 20α-HP and 4-pregnene-3α,20α-diol resulted in suppression of cell proliferation
  • Stimulation of cell proliferation with 5αP and inhibition with 3αHP were also observed in all other breast cell lines examined, whether ER/P-negative (MCF-10A, MDA-MB-231) or ER/P-positive (T47D, ZR-75-1) and whether requiring estrogen for tumorigenicity (MCF-7, T47D) or not (MDA-MB-231), or whether they are nontumorigenic (
  • αHP resulted in significant increases in apoptosis and decreases in mitosis, leading to significant decreases in total cell numbers. In contrast, treatment with 5αP resulted in decreases in apoptosis and increases in mitosis.
  • The opposing actions of 5αP and 3αHP on both cell anchorage and proliferation strengthen the hypothesis that the direction of P metabolism in vivo toward higher 5α-pregnane and lower 4-pregnene concentrations could promote breast neoplasia and lead to malignancy.
  • he effects on proliferation and adhesion were not due to P, but due to the 5α-reduced metabolites
  • The studies showed that binding of 5αP or 3αHP occurs in the plasma membrane fractions, but not in the nuclear or cytosolic compartments
  • separate high-specificity, high-affinity, low- capacity receptors for 5αP and 3αHP that are distinct from each other and from the well-studied nuclear/cytosolic P, estrogen, and androgen and corticosteroid receptors
  • The studies thus provided the first demonstration of the existence of specific P metabolite receptors
  • the receptor results suggest that the putative tumorigenic actions of 5αP may be significantly augmented by the estradiol-induced increases in 5αP binding and decreases in 3αHP binding.
  • Estradiol and 5αP resulted in significant dose-dependent increases, whereas 3αHP and 20αHP each resulted in dose-dependent decreases in total ER
  • In combination, estradiol + 5αP or 3αHP + 20αHP resulted in additive increases or decreases respectively in ER numbers.
  • The data suggest that the action of 5αP on breast cancer cells involves modulation of the MAPK signaling pathway
  • current evidence does not appear to support the notion that increased 5α-reductase activity/ expression might significantly alter androgen influences on breast tumor growth.
  • both testosterone and DHT inhibit cell growth more or less to the same extent
  • Note that 5α-reductase reaction is not reversible
  • Nathan Goodyear on 20 Feb 12
     
    Fantastic read on the effects of progesterone metabolism on tumor and cancer growth.  Tumorigenesis is not just about the hormone, hormone balance, but about the metabolism of hormones.  This is why premarin is so carcinogenic: it is primarily metabolized by the 4-OH estrone pathway.
Nathan Goodyear

Dutasteride affects progesterone metabolizing enzyme activity/expression in human breas... - 0 views

www.sciencedirect.com/...S0960076006001397

hormones progesterone cancer breast cancer 5alpha-pregnane 4-pregnenes progesterone metabolites 5 alpha reductase 5 alpha reductase inhibitors

shared by Nathan Goodyear on 07 Oct 16 - No Cached
  • Nathan Goodyear on 07 Oct 16
     
    Cell culture study finds that 5alpha-reductase inhibition decreased 5alpha-pregnanes and thus inhibited cell proliferation and detachment; this is in contrast to the 4 pregnenes that occur through the enzymes 3alpha-hydroxysteroid oxidoreductase and the 20alpha-hydroxysteroid oxidoreductase, which show anti cell proliferation and cell detachment.
Nathan Goodyear

Activity and expression of progesterone metabolizing 5α-reductase, 20α-hydrox... - 0 views

www.ncbi.nlm.nih.gov/...PMC154104

progesterone metabolites breast cancer 5alpha-reductase 5-alpha pregnene 5-alpha pregnenes 4-pregnene 4-pregnenes

shared by Nathan Goodyear on 30 Jan 14 - No Cached
  • Exposure of human breast cell lines (MCF-7, MCF-10A, and ZR-75-1) to 5α-pregnanes results in changes associated with neoplasia, including increased proliferation and decreased attachment [1], depolymerization of F-actin [2] and decreases in adhesion plaque-associated vinculin
  • Exposure to 4-pregnenes results, in general, in opposite (anti-cancer-like) effects
  • 5αR1 has been detected in various androgen-independent organs, such as the liver and brain
  • ...10 more annotations...
  • 5αR2 has been found predominantly in androgen-dependent organs, such as epididymis and prostate
  • The 5α-pregnanes:4-pregnenes ratio was about 8-fold higher in tumorous than in nontumorous breast tissue after an 8-hour incubation with [14C]progesterone
  • Studies with breast cell lines, showing that 5α-pregnanes stimulate proliferation and decrease attachment of cells
  • both tissue and breast cell line studies suggest that an elevated level of progesterone 5α-reductase activity may be an indicator of breast tumorigenesis, regardless of presence or absence of ER and/or PR
  • 5αR1 is the main isoform expressed in human breast carcinomas [29] and that 5αR2 may not be associated with risk of breast cancer
  • the differences in 5α-pregnane production between the cells is due primarily to a difference in 5αR1 expression
  • As in the case of 5α-reductase activity, the presence or absence of ER and PR do not appear to be related to 5α-reductase expression.
  • the conversion of progesterone to the cancer promoting 5α-pregnanes is significantly higher in the human tumorigenic breast cell lines
  • lthough both 5αR1 and 5αR2 are expressed by these cells, the elevated 5α-reductase activity appears to be the result of significantly greater expression of 5αR1
  • Changes in progesterone metabolizing enzyme expression (resulting in enzyme activity changes) may be responsible for promoting breast cancer progression due to increased production of tumor-promoting 5α-pregnanes and decreased production of anti-cancer 20α – and 3α-4-pregnenes
  • Nathan Goodyear on 30 Jan 14
     
    balance of enzyme production between 5alpha-reductase and 20alpha-hydroxysteroid oxidoreductase and 3alpha(beta)-hydroxysteroid oxidoreductase play role in carcinogenesis and proliferation in the balance of production of progesterone metabolites. The 5alpha pregnenes are pro carcinogenic  and the 4-pregnenes are anti carcinogenic.
Nathan Goodyear

Anticancer mechanisms of cannabinoids - 0 views

www.ncbi.nlm.nih.gov/...PMC4791144

THC cannabinoids cancer

shared by Nathan Goodyear on 18 Sep 18 - No Cached
  • modulating key cell signalling pathways involved in the control of cancer cell proliferation and survival
  • cannabinoids inhibit angiogenesis and decrease metastasis in various tumour types in laboratory animals
  • Cannabis sativa L. (marijuana)
  • ...41 more annotations...
  • of the approximately 108 cannabinoids produced by C. sativa, Δ9-tetrahydrocannabinol (thc) is the most relevant because of its high potency and abundance in plant preparations
  • Tetrahydrocannabinol exerts a wide variety of biologic effects by mimicking endogenous substances—the endocannabinoids anandamide3 and 2-arachidonoylglycerol4,5—that engage specific cell-surface cannabinoid receptors
  • the cb2 receptor was initially described to be present in the immune system6, but was more recently shown to also be expressed in cells from other origins
  • transient receptor potential cation channel subfamily V, member 1
  • orphan G protein–coupled receptor 55
  • Most of the effects produced by cannabinoids in the nervous system and in non-neural tissues rely on cb1 receptor activation
  • two major cannabinoid-specific receptors—cb1 and cb2
  • cardiovascular tone, energy metabolism, immunity, and reproduction
  • cannabinoids are well known to exert palliative effects in cancer patients
  • best-established use is the inhibition of chemotherapy-induced nausea and vomiting
  • thc and other cannabinoids exhibit antitumour effects in a wide array of animal models of cancer
  • cannabinoid receptors and their endogenous ligands are both generally upregulated in tumour tissue compared with non-tumour tissue
  • cb2 promotes her2 (human epidermal growth factor receptor 2) pro-oncogenic signalling in breast cancer
  • pharmacologic activation of cannabinoid receptors decreases tumour growth
  • endocannabinoid signalling can also have a tumour-suppressive role
  • pharmacologic stimulation of cb receptors is, in most cases, antitumourigenic. Nonetheless, a few reports have proposed a tumour-promoting effect of cannabinoids
  • most prevalent effect is the induction of cancer cell death by apoptosis and the inhibition of cancer cell proliferation
  • impair tumour angiogenesis and block invasion and metastasis
  • thc and other cannabinoids induce the apoptotic death of glioma cells by cb1- and cb2-dependent stimulation
  • Autophagy is primarily a cytoprotective mechanism, although its activation can also lead to cell death
  • autophagy is important for cannabinoid antineoplastic activity
  • autophagy is upstream of apoptosis in the mechanism of cannabinoid-induced cell death
  • the effect of cannabinoids in hormone- dependent tumours might rely, at least in part, on the ability to interfere with the activation of growth factor receptors
  • glioma cells), pharmacologic blockade of either cb1 or cb2 prevents cannabinoid-induced cell death with similar efficacy
  • other types of cancer cells (pancreatic48, breast24, or hepatic43 carcinoma cells, for example), antagonists of cb2 but not of cb1 inhibit cannabinoid antitumour actions
  • thc promotes cancer cell death in a cb1- or cb2-dependent manner (or both) at lower concentrations
  • cannabidiol (cbd), a phytocannabinoid with a low affinity for cannabinoid receptors15, and other marijuana-derived cannabinoids57 have also been proposed to promote the apoptotic death of cancer cells acting independently of the cb1 and cb2 receptors
  • In cancer cells, cannabinoids block the activation of the vascular endothelial growth factor (vegf) pathway, an inducer of angiogenesi
  • In vascular endothelial cells, cannabinoid receptor activation inhibits proliferation and migration, and induces apoptosis
  • cb1 or cb2 receptor agonists (or both) reduce the formation of distant tumour masses in animal models of both induced and spontaneous metastasis, and inhibit adhesion, migration, and invasiveness of glioma64, breast65,66, lung67,68, and cervical68 cancer cells in culture
  • the ceramide/p8–regulated pathway plays a general role in the antitumour activity of cannabinoids targeting cb1 and cb2
  • cbd, by acting independently of the cb1 and cb2 receptors, produces a remarkable anti-tumour effect—including reduction of invasiveness and metastasis
  • cannabinoids can also enhance immune system–mediated tumour surveillance in some contexts
  • ability of thc to reduce inflammation75,76, an effect that might prevent certain types of cancer
  • recent observations suggest that the combined administration of cannabinoids with other anticancer drugs acts synergistically to reduce tumour growth
  • combined administration of gemcitabine (the benchmark agent for the treatment of pancreatic cancer) and various cannabinoid agonists synergistically reduced the viability of pancreatic cancer cells
  • Other reports indicated that anandamide and HU-210 might also enhance the anticancer activity of paclitaxel89 and 5-fluorouracil90 respectively
  • Combined administration of thc and cbd enhances the anticancer activity of thc and reduces the dose of thc needed to induce its tumour growth-inhibiting activity
  • Preclinical animal models have yielded data indicating that systemic (oral or intraperitoneal) administration of cannabinoids effectively decreases tumour growth
  • Combinations of cannabinoids with classical chemotherapeutic drugs such as the alkylating agent temozolomide (the benchmark agent for the management of glioblastoma80,84) have been shown to produce a strong anticancer action in animal models
  • pharmacologic inhibition of egfr, erk83, or akt enhances the cell-death-promoting action of thc in glioma cultures (unpublished observations by the authors), which suggests that targeting egfr and the akt and erk pathways could enhance the antitumour effect of cannabinoids
  • Nathan Goodyear on 18 Sep 18
     
    Good review of the anticancer effects of cananbinoids.
Nathan Goodyear

Hormetic dose response to L-ascorbic acid as an anti-cancer drug in colorectal cancer c... - 0 views

www.nature.com/...s41598-018-29386-7

hermetic dose response prooxidative low dose vitamin C vitamin sodium dependent vitamin C transporter High dose IV vitamin C SVCT C high dose vitamin C

shared by Nathan Goodyear on 11 Aug 22 - No Cached
  • Nathan Goodyear on 11 Aug 22
     
    Low dose vitamin C, via SVCT, increases tumor proliferation; whereas high dose decreases tumor proliferation.
Nathan Goodyear

In vivo loss-of-function screens identify KPNB1 as a new druggable oncogene in epitheli... - 0 views

www.pnas.org/E7301

Ivermectin cancer ovarian cancer oncogene oncogenes

shared by Nathan Goodyear on 20 Mar 18 - No Cached
  • we functionally validated a potent EOC oncogene, KPNB1, and showed its clinical relevance to human EOC
  • a well-established antiparasitic drug, ivermectin, has antitumor effects on EOC through its inhibition of KPNB1
  • EOC has high intertumor and intratumor heterogeneity at the molecular and epigenetic levels
  • ...22 more annotations...
  • the mortality rate of EOC has not been significantly changed for several decades
  • Sequencing revealed that almost all tumors (96%) had mutations in TP53, which serves as a major driver of this cancer
  • Low-prevalence but statistically significant mutations in nine other genes including NF1, BRCA1, BRCA2, RB1, and CDK12 were also identified, but the majority of genes were mutated at low frequency, making it difficult to distinguish between driver and passenger mutations
  • KPNB1 inhibition via any of three KPNB1 siRNAs or importazole treatment induced apoptosis in human EOC cell lines (Fig. 3 A–F and Fig. S4), and was accompanied by an increase in the expression levels of the proapoptotic proteins BAX and cleaved caspase-3
  • Stable overexpression of KPNB1 in SKOV3 and OVCAR3 (Fig. S6) significantly accelerated cell proliferation/survival (Fig. 5 A–C), confirming that KPNB1 functions as an oncogene in EOC
  • KPNB1 overexpression significantly decreased caspase-3/7 activity (Fig. 5D), in addition to the expression levels of cleaved caspase-3 and BAX proteins (Fig. 5E). KPNB1 overexpression also decreased p21 and p27 protein levels (Fig. 5E), as opposed to their increase by KPNB1 inhibition
  • KPNB1 functions as an antiapoptotic and proproliferative oncogene in EOC.
  • Patients with higher expression levels of KPNB1 showed earlier recurrence and worse prognosis than those with lower expression levels of KPNB1
  • KPNB1 acts as an oncogene in human EOC and represents a promising therapeutic target.
  • ivermectin treatment suppressed cell proliferation/viability in a dose-dependent manner (Fig. 7A), indicating that it exerts an antitumor effect on EOC
  • ivermectin also induced apoptosis
  • ivermectin increased the expression levels of BAX, and cleaved PARP, as well as p21 and p27
  • KPNB1 inhibition is responsible for the antitumor effect of ivermectin
  • we found that ivermectin synergistically reduced cell proliferation/viability in combination with paclitaxel in human EOC cells
  • Single treatment of ivermectin or paclitaxel reduced tumor growth in nude mice, but, notably, combination treatment of ivermectin and paclitaxel almost completely suppressed tumor growth
  • ERBB2, is amplified and overexpressed in many cancers, including breast (31), ovary (31), colon (32), bladder (33), non-small-cell lung (34), and gastric cancer (35), and is a poor prognostic factor in certain cancer types
  • KPNB1 was the second-highest-ranked gene identified in our screen
  • Increased KPNB1 protein levels have been reported in several cancers, including cervical cancer (42), hepatocellular carcinoma (43), and glioma (44), suggesting KPNB1’s oncogenic potential in these tumor types
  • our findings suggest that KPNB1 might serve as a master regulator of cell cycle by regulating several cell cycle-related proteins, including p21, p27, and APC/C family members
  • higher and/or more-frequent doses of ivermectin than currently approved for humans are well tolerated in humans
  • none of the mice in this study treated with the effective dosage of ivermectin for in vivo anticancer therapy showed severe adverse event
  • we found that the combination of ivermectin and paclitaxel produces a stronger antitumor effect on EOC cell lines than either drug alone
  • Nathan Goodyear on 20 Mar 18
     
    Ivermectin found to be pro-apoptotic for the epithelial ovarian cancer oncogene, KPNB1 in in Vivo study.  This effective anti-parasitic drug inhibits the KPNB1 oncogene.
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
  • ...13 more annotations...
  • 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.
Nathan Goodyear

PPARs, Obesity, and Inflammation - 0 views

www.ncbi.nlm.nih.gov/...PMC1783744

obesity inflammation PPARs perioxisome proliferator-activated receptor

shared by Nathan Goodyear on 16 Jan 12 - No Cached
  • increase of 61% within 10 years
  • Many of the inflammatory markers found in plasma of obese individuals appear to originate from adipose tissue
  • obesity is a state of chronic low-grade inflammation that is initiated by morphological changes in the adipose tissue.
  • ...19 more annotations...
  • secretion of MCP-1, resistin, and other proinflammatory cytokines is increased by obesity, the adipose secretion of the anti-inflammatory protein adiponectin is decreased
  • the peroxisome proliferators- activated receptor (PPAR) family are involved in the regulation of inflammation and energy homestasis
  • natural agonists, including unsaturated fatty acids and eicosanoids
  • PPARα also regulates inflammatory processes, mainly by inhibiting inflammatory gene expression
  • upregulation of COX-2 is seen in alcoholic steatohepatitis and nonalcoholic steatohepatitis and has been directly linked to the progression of steatosis to steatohepatitis, the inhibitory effect of PPARα on COX-2 may reduce steatohepatitis
  • PPARα agonists have a clear anorexic effect resulting in decreased food intake, evidence is accumulating that PPARα may also directly influence adipose tissue function, including its inflammatory status.
  • PPARα may govern adipose tissue inflammation in three different ways: (1) by decreasing adipocyte hypertrophy, which is known to be connected with a higher inflammatory status of the tissue [3, 11, 59], (2) by direct regulation of inflammatory gene expression via locally expressed PPARα, or (3) by systemic events likely originating from liver
  • PPARγ is considered the master regulator of adipogenesis
  • Unsaturated fatty acids and several eicosanoids serve as endogenous agonists of PPARγ
  • PPARγ2, which is adipose-tissue specific
  • two different molecular mechanisms have been proposed by which anti-inflammatory actions of PPARγ are effectuated: (1) via interference with proinflammatory transcription factors including STAT, NF-κB, and AP-1
  • and (2) by preventing removal of corepressor complexes from gene promoter regions resulting in suppression of inflammatory gene transcription
  • diet-induced obesity is associated with increased inflammatory gene expression in adipose tissue via adipocyte hypertrophy and macrophage infiltration
  • PPARγ is able to reverse macrophage infiltration, and subsequently reduces inflammatory gene expression
  • Inflammatory adipokines mainly originate from macrophages which are part of the stromal vascular fraction of adipose tissue [18, 19], and accordingly, the downregulation of inflammatory adipokines in WAT by PPARγ probably occurs via effects on macrophages
  • By interfering with NF-κB signaling pathways, PPARγ is known to decrease inflammation in activated macrophages
  • Recent data suggest that activation of PPARγ in fatty liver may protect against inflammation
  • PPARs may influence the inflammatory response either by direct transcriptional downregulation of proinflammatory genes
  • anti-inflammatory properties of PPARs in human obesity
  • Nathan Goodyear on 16 Jan 12
     
    PPARs play pivotal in obesity.  PPARs appear to reduce the inflammatory cascade associated with obesity.  Downregulation of PPARs are associated with increased inflammation.  Natural PPARs include unsaturated fats and eicosanoids.
Nathan Goodyear

Dietary supplementation with eicosapentaenoic and ... [Int J Cancer. 1998] - PubMed result - 0 views

www.ncbi.nlm.nih.gov/...9495237

Omega-3 DHA EPA cancer

shared by Nathan Goodyear on 11 Feb 11 - No Cached
  • t is concluded from the results of the present study that the anti-tumoral effect of EPA is related mainly to its inhibition of cell proliferation, whereas that of DHA corresponds with its induction of apoptosis. The alterations in fatty-acid composition induced by EPA or DHA appear to be factors underlying their differential actions on cell proliferation and apoptosis.
  • Nathan Goodyear on 11 Feb 11
     
    Omega-3, DHA and EPA, work differently in their anti-cancer effects
Nathan Goodyear

Ivermectin: enigmatic multifaceted 'wonder' drug continues to surprise and exceed expec... - 0 views

www.nature.com/ja201711

Ivermectin cancer

shared by Nathan Goodyear on 19 Mar 18 - No Cached
  • The avermectins are known to possess pronounced antitumor activity
  • Over the past few years, there have been steadily increasing reports that ivermectin may have varying uses as an anti-cancer agent, as it has been shown to exhibit both anti-cancer and anti-cancer stem cell properties
  • In human ovarian cancer and NF2 tumor cell lines, high-dose ivermectin inactivates protein kinase PAK1 and blocks PAK1-dependent growth
  • ...13 more annotations...
  • PAK1 is essential for the growth of more than 70% of all human cancers, including breast, prostate, pancreatic, colon, gastric, lung, cervical and thyroid cancers, as well as hepatoma, glioma, melanoma, multiple myeloma and for neurofibromatosis tumors
  • Ivermectin suppresses breast cancer by activating cytostatic autophagy, disrupting cellular signaling in the process, probably by reducing PAK1 expression
  • Cancer stem cells are a key factor in cancer cells developing resistance to chemotherapies and these results indicate that a combination of chemotherapy agents plus ivermectin could potentially target and kill cancer stem cells, a paramount goal in overcoming cancer
  • Triple-negative breast cancers, which lack estrogen, progesterone and HER2 receptors, account for 10–20% of breast cancers and are associated with poor prognosis
  • Ivermectin addition led to transcriptional modulation of genes associated with epithelial–mesenchymal transition and maintenance of a cancer stem cell phenotype in triple-negative breast cancers cells, resulting in impairment of clonogenic self-renewal in vitro and inhibition of tumor growth and metastasis in vivo
  • Ivermectin-induced cytostatic autophagy also leads to suppression of tumor growth in breast cancer xenografts, causing researchers to believe there is scope for using ivermectin to inhibit breast cancer cell proliferation and that the drug is a potential treatment for breast cancer
  • ivermectin synergizes with the chemotherapy agents cytarabine and daunorubicin to induce cell death in leukemia cells
  • Ivermectin inhibits proliferation and increases apoptosis of various human cancers
  • Activation of WNT-TCF signaling is implicated in multiple diseases, including cancers of the lungs and intestine,
  • A new screening system has found that ivermectin inhibits the expression of WNT-TCF targets
  • It represses the levels of C-terminal β-catenin phosphoforms and of cyclin D1 in an okadaic acid-sensitive manner, indicating its action involves protein phosphatases
  • In vivo, ivermectin selectively inhibits TCF-dependent, but not TCF-independent, xenograft growth without side effects
  • ivermectin has an exemplary safety record, it could swiftly become a useful tool as a WNT-TCF pathway response blocker to treat WNT-TCF-dependent diseases, encompassing multiple cancers.117
  • Nathan Goodyear on 19 Mar 18
     
    Ivermectin shows promise and usefullness in several cancer types.  This is a review article.
Nathan Goodyear

Cancers | Free Full-Text | A Second WNT for Old Drugs: Drug Repositioning against WNT-D... - 0 views

www.mdpi.com/htm

cancer Niclosamide ivermectin Wnt

shared by Nathan Goodyear on 16 Apr 18 - No Cached
  • To date nearly half of known human tumors show a dysregulation of the WNT signaling pathway
  • It should be also noted that the WNT pathway is not exclusively employed during development or overactivated in cancer. In adults many healthy tissues rely on it for renewal and homeostasis maintenance, most notably the intestine, haematopoietic system, hair, bones and skin. Therefore one might expect adverse reactions in all these organ systems, which has indeed been observed for many WNT-targeting compounds upon attempts to push them into the clinics
  • The intestine seems to be the most vulnerable in this regard
  • ...8 more annotations...
  • Ivermectin inhibits proliferation of human colon cancer and lung cancer cells both in vitro and in vivo
  • The anti-proliferative action, affecting both the bulk tumor cells and CSCs, was linked in this study to inhibition of WNT signaling
  • the anti-WNT IC50 of ivermectin is 5–10 times (~1–2 µM vs. 10 µM) lower than that of its toxic effect against chloride channels
  • oral bioavailability of the drug, as for other antiparasitic drugs discussed in this section, is very low
  • Toxicity studies in vivo have also demonstrated a wide therapeutic index for ivermectin
  • Its anti-proliferative activity has been demonstrated in a wide array of cancer cell lines representative of WNT-dependent cancers: non-small lung carcinoma [96], multiple myeloma [97], hepatoma [98], adrenocortical carcinoma [99], ovarian cancer [100] and glioblastoma
  • Niclosamide inhibits the canonical WNT pathway
  • In addition to inhibiting the canonical WNT pathway, niclosamide may mediate its anticancer activities through several other signaling pathways such as NOTCH [107], MTOR [108], NF-κB [97] and STAT3 [96]
  • Nathan Goodyear on 16 Apr 18
     
    review article highlights older medications that have anti-Wnt pathway effects in cancer.  Roughly, 50% of cancer involve upregulated Wnt pathway activity. Other drugs of note: metformin
Nathan Goodyear

Contribution of Reactive Oxygen Species to Ovarian Cancer Cell Growth Arrest and Killin... - 0 views

cancer artesunate ROS

shared by Nathan Goodyear on 06 Jun 19 - No Cached
  • Nathan Goodyear on 06 Jun 19
     
    Artesunate increased ROS in ovarian cancer cells that lead to G1 cell cycle arrest and halt in proliferation.
Nathan Goodyear

The anti-malarial drug artesunate causes cell cycle arrest and apoptosis of triple-nega... - 0 views

www.ncbi.nlm.nih.gov/...30660598

breast cancer cancer artesunate

shared by Nathan Goodyear on 01 Jul 19 - No Cached
  • Nathan Goodyear on 01 Jul 19
     
    ART inhibited breast cancer cell proliferation via a reactive oxygen species (ROS)-dependent G2/M arrest and ROS-independent G1 arrest. ART-treated MDA-MB-468 and SK-BR-3 cells also experienced apoptotic cell death, which was both ROS- and iron-dependent. ART-induced oxidative stress caused the loss of mitochondrial outer membrane integrity and damage to the cellular DNA of MDA-MB-468 and SK-BR-3 cells. Only abstract available...I will post full article once available.
Nathan Goodyear

The Anti-malarial Drug Artesunate Blocks Wnt/β-catenin Pathway and Inhibits G... - 0 views

www.eurekaselect.com/...article

artesunate cancer Wnt

shared by Nathan Goodyear on 23 Aug 19 - No Cached
  • Nathan Goodyear on 23 Aug 19
     
    In vitro study finds that artesunate blocks Wnt pathway a very important signaling pathway for cancer cell proliferation and TME immunosuppression.
Nathan Goodyear

Testosterone: a vascular hormone in health and disease - 0 views

joe.endocrinology-journals.org/...R47.full

testosterone hormone health disease hormones men male cardiovascular disease CVD

shared by Nathan Goodyear on 13 May 13 - No Cached
  • Testosterone has beneficial effects on several cardiovascular risk factors, which include cholesterol, endothelial dysfunction and inflammation
  • In clinical studies, acute and chronic testosterone administration increases coronary artery diameter and flow, improves cardiac ischaemia and symptoms in men with chronic stable angina and reduces peripheral vascular resistance in chronic heart failure.
  • testosterone is an L-calcium channel blocker and induces potassium channel activation in vascular smooth muscle cells
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  • Animal studies have consistently demonstrated that testosterone is atheroprotective, whereas testosterone deficiency promotes the early stages of atherogenesis
  • there is no compelling evidence that testosterone replacement to levels within the normal healthy range contributes adversely to the pathogenesis of CVD (Carson & Rosano 2011) or prostate cancer (Morgentaler & Schulman 2009)
  • bidirectional effect between decreased testosterone concentrations and disease pathology exists as concomitant cardiovascular risk factors (including inflammation, obesity and insulin resistance) are known to reduce testosterone levels and that testosterone confers beneficial effects on these cardiovascular risk factors
  • Achieving a normal physiological testosterone concentration through the administration of testosterone replacement therapy (TRT) has been shown to improve risk factors for atherosclerosis including reducing central adiposity and insulin resistance and improving lipid profiles (in particular, lowering cholesterol), clotting and inflammatory profiles and vascular function
  • It is well known that impaired erectile function and CVD are closely related in that ED can be the first clinical manifestation of atherosclerosis often preceding a cardiovascular event by 3–5 years
  • no decrease in the response (i.e. no tachyphylaxis) of testosterone and that patient benefit persists in the long term.
  • free testosterone levels within the physiological range, has been shown to result in a marked increase in both flow- and nitroglycerin-mediated brachial artery vasodilation in men with CAD
  • Clinical studies, however, have revealed either small reductions of 2–3 mm in diastolic pressure or no significant effects when testosterone is replaced within normal physiological limits in humans
  • Endothelium-independent mechanisms of testosterone are considered to occur primarily via the inhibition of voltage-operated Ca2+ channels (VOCCs) and/or activation of K+ channels (KCs) on smooth muscle cells (SMCs)
  • Testosterone shares the same molecular binding site as nifedipine
  • Testosterone increases the expression of endothelial nitric oxide synthase (eNOS) and enhances nitric oxide (NO) production
  • Testosterone also inhibited the Ca2+ influx response to PGF2α
  • one of the major actions of testosterone is on NO and its signalling pathways
  • In addition to direct effects on NOS expression, testosterone may also affect phosphodiesterase type 5 (PDE5 (PDE5A)) gene expression, an enzyme controlling the degradation of cGMP, which acts as a vasodilatory second messenger
  • the significance of the action of testosterone on VSMC apoptosis and proliferation in atherosclerosis is difficult to delineate and may be dependent upon the stage of plaque development
  • Several human studies have shown that carotid IMT (CIMT) and aortic calcification negatively correlate with serum testosterone
  • t long-term testosterone treatment reduced CIMT in men with low testosterone levels and angina
  • neither intracellular nor membrane-associated ARs are required for the rapid vasodilator effect
  • acute responses appear to be AR independent, long-term AR-mediated effects on the vasculature have also been described, primarily in the context of vascular tone regulation via the modulation of gene transcription
  • Testosterone and DHT increased the expression of eNOS in HUVECs
  • oestrogens have been shown to activate eNOS and stimulate NO production in an ERα-dependent manner
  • Several studies, however, have demonstrated that the vasodilatory actions of testosterone are not reduced by aromatase inhibition
  • non-aromatisable DHT elicited similar vasodilation to testosterone treatment in arterial smooth muscle
  • increased endothelial NOS (eNOS) expression and phosphorylation were observed in testosterone- and DHT-treated human umbilical vein endothelial cells
  • Androgen deprivation leads to a reduction in neuronal NOS expression associated with a decrease of intracavernosal pressure in penile arteries during erection, an effect that is promptly reversed by androgen replacement therapy
  • Observational evidence suggests that several pro-inflammatory cytokines (including interleukin 1β (IL1β), IL6, tumour necrosis factor α (TNFα), and highly sensitive CRP) and serum testosterone levels are inversely associated in patients with CAD, T2DM and/or hypogonadism
  • patients with the highest IL1β concentrations had lower endogenous testosterone levels
  • TRT has been reported to significantly reduce TNFα and elevate the circulating anti-inflammatory IL10 in hypogonadal men with CVD
  • testosterone treatment to normalise levels in hypogonadal men with the MetS resulted in a significant reduction in the circulating CRP, IL1β and TNFα, with a trend towards lower IL6 compared with placebo
  • parenteral testosterone undecanoate, CRP decreased significantly in hypogonadal elderly men
  • Higher levels of serum adiponectin have been shown to lower cardiovascular risk
  • Research suggests that the expression of VCAM-1, as induced by pro-inflammatory cytokines such as TNFα or interferon γ (IFNγ (IFNG)) in endothelial cells, can be attenuated by treatment with testosterone
  • Testosterone also inhibits the production of pro-inflammatory cytokines such as IL6, IL1β and TNFα in a range of cell types including human endothelial cells
  • decreased inflammatory response to TNFα and lipopolysaccharide (LPS) in human endothelial cells when treated with DHT
  • The key to unravelling the link between testosterone and its role in atherosclerosis may lay in the understanding of testosterone signalling and the cross-talk between receptors and intracellular events that result in pro- and/or anti-inflammatory actions in athero-sensitive cells.
  • testosterone functions through the AR to modulate adhesion molecule expression
  • pre-treatment with DHT reduced the cytokine-stimulated inflammatory response
  • DHT inhibited NFκB activation
  • DHT could inhibit an LPS-induced upregulation of MCP1
  • Both NFκB and AR act at the transcriptional level and have been experimentally found to be antagonistic to each other
  • As the AR and NFκB are mutual antagonists, their interaction and influence on functions can be bidirectional, with inflammatory agents that activate NFκB interfering with normal androgen signalling as well as the AR interrupting NFκB inflammatory transcription
  • prolonged exposure of vascular cells to the inflammatory activation of NFκB associated with atherosclerosis may reduce or alter any potentially protective effects of testosterone
  • DHT and IFNγ also modulate each other's signalling through interaction at the transcriptional level, suggesting that androgens down-regulate IFN-induced genes
  • (Simoncini et al. 2000a,b). Norata et al. (2010) suggest that part of the testosterone-mediated atheroprotective effects could depend on ER activation mediated by the testosterone/DHT 3β-derivative, 3β-Adiol
  • TNFα-induced induction of ICAM-1, VCAM-1 and E-selectin as well as MCP1 and IL6 was significantly reduced by a pre-incubation with 3β-Adiol in HUVECs
  • 3β-Adiol also reduced LPS-induced gene expression of IL6, TNFα, cyclooxygenase 2 (COX2 (PTGS2)), CD40, CX3CR1, plasminogen activator inhibitor-1, MMP9, resistin, pentraxin-3 and MCP1 in the monocytic cell line U937 (Norata et al. 2010)
  • This study suggests that testosterone metabolites, other than those generated through aromatisation, could exert anti-inflammatory effects that are mediated by ER activation.
  • The authors suggest that DHT differentially effects COX2 levels under physiological and pathophysiological conditions in human coronary artery smooth muscle cells and via AR-dependent and -independent mechanisms influenced by the physiological state of the cell
  • There are, however, a number of systematic meta-analyses of clinical trials of TRT that have not demonstrated an increased risk of adverse cardiovascular events or mortality
  • The TOM trial, which was designed to investigate the effect of TRT on frailty in elderly men, was terminated prematurely as a result of an increased incidence of cardiovascular-related events after 6 months in the treatment arm
  • trials of TRT in men with either chronic stable angina or chronic cardiac failure have also found no increase in either cardiovascular events or mortality in studies up to 12 months
  • Evidence may therefore suggest that low testosterone levels and testosterone levels above the normal range have an adverse effect on CVD, whereas testosterone levels titrated to within the mid- to upper-normal range have at least a neutral effect or, taking into account the knowledge of the beneficial effects of testosterone on a series of cardiovascular risk factors, there may possibly be a cardioprotective action
  • The effect of testosterone on human vascular function is a complex issue and may be dependent upon the underlying androgen and/or disease status.
  • the majority of studies suggest that testosterone may display both acute and chronic vasodilatory effects upon various vascular beds at both physiological and supraphysiological concentrations and via endothelium-dependent and -independent mechanisms
  • Nathan Goodyear on 13 May 13
     
    Good deep look into the testosterone and CVD link.
Nathan Goodyear

Effects of Angiotensin, Vasopressin and Aldosterone on Proliferation of MCF-7 Cells and... - 0 views

ar.iiarjournals.org/...1843.full

cancer breast cancer renin angiotensin system aldosterone

shared by Nathan Goodyear on 10 Sep 18 - No Cached
  • The renin-angiotensin system (RAS) has been associated with local tumor growth, inflammation, angiogenesis and facilitation of metastasis
  • Aldosterone and vasopressin did not alter cellular growth (Figure 1) and did not alter doxorubicin sensitivity
  • angiotensin increased the growth of MCF-7 cells
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  • losartan
  • evidence that breast cancer chemotherapy can be influenced by anti-hypertensive treatment
  • Nathan Goodyear on 10 Sep 18
     
    upregulated RAS associated with stimulated breast cancer growth.  Anti-hypertensive therapy not only can it impact the cancer growth potential but also can augment chemotherapy.
Nathan Goodyear

Telomerase at the intersection of cancer and aging - 0 views

www.ncbi.nlm.nih.gov/...PMC3896987

telomere telomeres telomerase telomerase activator aging disease cancer

shared by Nathan Goodyear on 18 May 16 - No Cached
  • The anti-aging role of telomerase has been demonstrated to be largely mediated by its canonical role in elongating telomeres, which prevents the accumulation of critically short telomeres and loss of tissue homeostasis
  • Short telomeres, and subsequent DDR activation, could occur both in cancer and aging
  • increased abundance of short telomeres correlates with higher genomic instability and decreased longevity in various organisms, including mice, zebrafish, and yeast
  • ...15 more annotations...
  • mice deficient for telomerase or for telomere binding proteins are characterized by accelerated age-related defects
  • In humans, short telomeres are considered good indicators of an individual’s health status and correlate with both genetic and environmental factors
  • Although recent findings strongly support the idea that short telomeres drive several age-related diseases 38 we cannot exclude the possibility that in some situations short telomeres may be a consequence of the disease itself.
  • the current view is that telomerase deficiency may contribute to the early steps of cancer development by fueling chromosomal instability, while subsequent activation of telomerase may be necessary to allow tumor growth and tumor progression towards more malignant states
  • telomerase activation can be an early event in cancer, it is not necessary for cancer initiation
  • telomerase can stimulate tumor progression by ensuring maintenance of telomeres above a critically short length, thus preventing induction of cellular senescence or apoptosis
  • Almost all human cancers present activation of telomerase as a hallmark, most likely as a mechanism to allow unlimited cell proliferation of tumor cells
  • recent evidence demonstrated that short telomeres alone could lead to genomic instability and cancer
  • Getting rid of telomerase can also be problematic; the lack of telomerase could lead to increased chromosomal instability, which in turn could be at the basis for cancer initiation when tumor suppressor barriers are bypassed
  • telomerase activation is a potential therapeutic strategy for the treatment of age-related diseases
  • telomerase activation in adult or old mice by means of a gene therapy strategy was shown to be sufficient to improve metabolic fitness, neuromuscular capacity, and prevent bone loss, as well as significantly increase both median and maximum longevity, without increased cancer incidence
  • These studies suggest that telomerase expression could be considered a feasible approach to reverse tissue dysfunction and extend healthy lifespan without increasing cancer incidence
  • humans almost completely lose telomerase activity from somatic tissues in the adulthood
  • a change of paradigm seems to be occurring in telomerase biology, with a switch from viewing telomerase as fueling cancer to reversing aging
  • Telomerase expression in a background of high levels of tumor suppressors or in aged organisms seems to prevent its expected pro-cancer activity and yet it still functions as an anti-aging factor
  • Nathan Goodyear on 18 May 16
     
    Telomerase activity and longer telomere length is shown to correlated inversely with many chronic diseases of aging.  In contrast, telomerase activity is found to be involved in carcinogenesis.  Increased carcinogenic potential of telomerase activity has not borne out in studies.  In addition, increased CD8 cell activity as a result of telomerase activation will actually decrease carcinogenic potential via NK activation.
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