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Nathan Goodyear

The river blindness drug Ivermectin and related macrocyclic lactones inhibit WNT-TCF pa... - 0 views

  • WNT signaling
  • early colon cancers commonly display loss of function of the tumor suppressor Adenomatous polyposis coli (APC), a key component of the β-CATENIN destruction complex
  • Other cancers also show an active canonical WNT pathway; these include carcinomas of the lung, stomach, cervix, endometrium, and lung as well as melanomas and gliomas
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  • In normal embryogenesis and homeostasis, the canonical WNT pathway is activated by secreted WNT ligands produced in highly controlled context-dependent manners and in precise amounts. WNT activity is transduced in the cytoplasm, inactivates the APC destruction complex, and results in the translocation of activate β-CATENIN to the nucleus, where it cooperates with DNA-binding TCF/LEF factors to regulate WNT-TCF targets and the ensuing genomic response
  • beyond the loss of activity of the APC destruction complex, for instance throughAPC mutation, phosphorylation of β-CATENIN at C-terminal sites is required for the full activation of WNT-TCF signaling and the ensuing WNT-TCF responses in cancer.
  • The WNT-TCF response blockade that we describe for low doses of Ivermectin suggests an action independent to the deregulation of chloride channels
  • involve the repression of the levels of C-terminally phosphorylated β-CATENIN forms and of CYCLIN D1, a critical target that is an oncogene and positive cell cycle regulator.
  • the Avermectin single-molecule derivative Selamectin, a drug widely used in veterinarian medicine (Nolan & Lok, 2012), is ten times more potent acting in the nanomolar range
  • Ivermectin also diminished the protein levels of CYCLIN D1, a direct TCF target and oncogene, in both HT29 and H358 tumor cells
  • Activated Caspase3 was used as a marker of apoptosis by immunohistochemistry 48 h after drug treatment. Selamectin and Ivermectin induced up to a sevenfold increase in the number of activated Caspase3+ cells in two primary (CC14 and CC36) and two cell line (DLD1 and Ls174T) colon cancer cell types (Fig​(Fig2C).2C). All changes were significative
  • The strong downregulation of the expression of the intestinal stem cell genesASCL2 andLGR5 (van der Flieret al, 2009; Scheperset al, 2012; Zhuet al, 2012b) by Ivermectin and Selamectin (Fig​(Fig2D)2D) raised the possibility that these drugs could affect WNT-TCF-dependent colon cancer stem cell behavior
  • Pre-established H358 tumors responded to Ivermectin showing a ˜ 50% repression of growth
  • Ivermectin hasin vivo efficacy against human colon cancer xenografts sensitive to TCF inhibition with no discernable side effects
  • Ivermectin (Campbellet al, 1983), an off-patent drug approved for human use, and related macrocyclic lactones, have WNT-TCF pathway response blocking and anti-cancer activities
  • these drugs block WNT-TCF pathway responses, likely acting at the level of β-CATENIN/TCF function, affecting β-CATENIN phosphorylation status.
  • anti-WNT-TCF activities of Ivermectin and Selamectin
  • Ivermectin has a well-known anti-parasitic activity mediated via the deregulation of chloride channels, leading to paralysis and death (Hibbs & Gouaux, 2011; Lynagh & Lynch, 2012). The same mode of action has been suggested to underlie the toxicity of Ivermectin for liquid tumor cells and the potentiation or sensitization effect of Avermectin B1 on classical chemotherapeutics
  • the specificity of the blockade of WNT-TCF responses we document, at low micromolar doses for Ivermectin and low nanomolar doses for Selamectin, indicate that the blockade of WNT-TCF responses and chloride channel deregulation are distinct modes of action
  • What is key then is to find a dose and a context where the use of Ivermectin has beneficial effects in patients, paralleling our results with xenografts in mice.
  • Cell toxicity appears at doses greater (> 10 μM for 12 h or longer or > 5 μM for 48 h or longer for Ivermectin) than those required to block TCF responses and induce apoptosis.
  • Our data point to a repression of WNT-β-CATENIN/TCF transcriptional responses by Ivermectin, Selamectin and related macrocylic lactones.
  • (i) The ability of Avermectin B1 to inhibit the activation of WNT-TCF reporter activity by N-terminal mutant (APC-insensitive) β-CATENIN as detected in our screen
  • (ii) The ability of Avermectin B1, Ivermectin, Doramectin, Moxidectin and Selamectin to parallel the modulation of WNT-TCF targets by dnTCF
  • (iii) The finding that the specific WNT-TCF response blockade by low doses of Ivermectin and Selamectin is reversed by constitutively active TCF
  • (iv) The repression of key C-terminal phospho-isoforms of β-CATENIN resulting in the repression of the TCF target and positive cell cycle regulator CYCLIN D1 by Ivermectin and Selamectin
  • (v) The specific inhibition ofin-vivo-TCF-dependent, but notin-vivo-TCF-independent cancer cells by Ivermectin in xenografts.
  • These results together with the reduction of the expression of the colon cancer stem cell markersASCL2 andLGR5 (e.g., Hirschet al, 2013; Ziskinet al, 2013) raise the possibility of an inhibitory effect of Ivermectin, Selamectin and related macrocyclic lactones on TCF-dependent cancer stem cells.
  • the capacity of cancer cells to form 3D spheroids in culture, as well as the growth of these, is also WNT-TCF-dependent (Kanwaret al, 2010) and they were also affected by Ivermectin treatment
  • If Ivermectin is specific, it should only block TCF-dependent tumor growth. Indeed, the sensitivity and insensitivity of DLD1 and CC14 xenografts to Ivermectin treatment, respectively, together with the desensitization to Ivermectin actionin vivo by constitutively active TCF provide evidence of the specificity of this drug to block an activated WNT-TCF pathway in human cancer.
  • Ivermectin has a good safety profile since onlyin-vivo-dnTCF-sensitive cancer xenografts are responsive to Ivermectin treatment, and we have not detected side effects in Ivermectin-treated mice at the doses used
  • previous work has shown that side effects from systemic treatments with clinically relevant doses in humans are rare (Yang, 2012), that birth defects were not observed after exposure of pregnant mothers (Pacquéet al, 1990) and that this drug does not cross the blood–brain barrier (Kokozet al, 1999). Similarly, only dogs with mutantABCB1 (MDR1) alleles leading to a broken blood–brain barrier show Ivermectin neurotoxicity (Mealeyet al, 2001; Orzechowskiet al, 2012)
  • Indications may include treatment for incurable β-CATENIN/TCF-dependent advanced and metastatic human tumors of the lung, colon, endometrium, and other organs.
  • Ivermectin, Selamectin, or related macrocyclic lactones could also serve as topical agents for WNT-TCF-dependent skin lesions and tumors such as basal cell carcinomas
  • they might also be useful as routine prophylactic agents, for instance against nascent TCF-dependent intestinal tumors in patients with familial polyposis and against nascent sporadic colon tumors in the general aging population
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    Ivermectin, a common anti-parasitic, found to inhibit WTF-TCF pathway and decrease c-terminal phosophorylaiton of Beta-CATENIN all resulting in increased aptosis and inhibition of cancer growth in colon cancer cell lines and lung cancer cell lines.
Nathan Goodyear

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

  • 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
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  • 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]
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    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

Treatment-induced secretion of WNT16B promotes tumor growth and acquired resistance to ... - 0 views

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    increased expression of Wnt family member wingless-type MMTV integration site family member 16B (WNT16B) by the tumor microenvironment in response to cytotoxic damage and signals through the canonical Wnt pathway to promote tumor growth and chemotherapy resistance
Nathan Goodyear

Telomerase at the intersection of cancer and aging - 0 views

  • 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
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  • 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
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    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.
Nathan Goodyear

The Canonical NF-κB Pathway Governs Mammary Tumorigenesis in Transgenic Mice ... - 0 views

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    NF-kappaB and the associated inflammatory pathways are associated with tumor growth, vascular growth within the tumor, and increased migration of macrophages--thus more inflammation.  When NF-kappaB inhibition was achieved, tumor macrophages and new tumor blood vessel growth was decreased.  Reduced blood vessel growth to the tumor has implications on metastasis of the tumor.
Nathan Goodyear

5alpha-androstane-3alpha,17beta-diol selectively activates the canonical PI3K/AKT pathw... - 0 views

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    3-alpha androstanediol known to stimulate prostate cancer cell proliferation via ER alpha with little no affinity for AR.  This study finds cell signaling via AR independent mechanism--AKT pathway.
Nathan Goodyear

Estrogenic regulation of skeletal muscle proteome: a study of premenopausal women and p... - 0 views

  • Female aging is characterized by menopausal change in sex steroid hormones concomitant to increase in aging-related decrements in skeletal muscle performance that can be attenuated by HRT use
  • The major canonical pathways found to be differentially regulated included mitochondrial dysfunction, oxidative phosphorylation, glycolysis, and TCA-cycle, strong indicators for affected energy metabolism
  • E2 to exert anti-apoptotic effects in muscle progenitor cells by improving mitochondrial function
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  • E2 is a major regulator of human skeletal muscle signaling in women
  • After menopause, when ovarian E2 production is ceased, the prevalence of cardio-metabolic diseases increases. Our result that different trajectories of the energy pathways in the skeletal muscle may be regulated by E2 provides candidate molecules as key targets for future interventions to prevent or treat postmenopausal metabolic dysregulation
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    Study finds Estradiol regulates human skeletal muscle cell signaling (mitochondrial function, oxidative phosphorylation, glycolysis, and TCA cycle) in study of pre/post menopause women through proteome analysis. This study would have been complete if they had carried to search beyond that of protein to epigenetics.
trungtamnamkhoa

THỦ DÂM NHIỀU LỢI ÍT HẠI NHIỀU - Sức Khoẻ Nam Giới - 1 views

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    Thủ dâm hay "bắt sóc bỏ lọ" là 1 hành động tự thỏa mãn tình dục bằng đôi tay. Theo nghiên cứu hơn 60 % nam giới mất đi lần đầu tiên do chính bàn tay của mình. Đây là cách mà nam giới giải tỏa các bức xúc tình dục khi chưa có cách nào khác giải quyết nhu cầu tình dục của bản thân như xa vợ, chưa có vợ, chưa có người yêu. Thủ dâm chừng mực sẽ giúp bạn giải tỏa bức xúc tức thời, cảm thấy thoải mái và trong giới hạn nào đó thì rất tốt cho sức khỏe của bạn. Thủ dâm giúp bạn tránh khỏi các bệnh lây qua đường tình dục tuyệt đối, tuy nhiên thủ dâm quá mức sẽ dẫn đến những tác hại nguy hiểm cho bản thân.
Nathan Goodyear

Anti-helminth compound niclosamide downregulates Wnt Signaling and elicits antitumor re... - 0 views

  • Others have reported that niclosamide inhibits the NF-κB pathway in leukemia cell lines (26) or mTOR signaling in MCF-7 breast cancer cells
  • niclosamide enhances the anti-tumor effect of oxaliplatin
  • In the more rapidly growing tumor (HCT116), a dose of 200 mg/kg of body weight was needed to suppress the tumor growth
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  • however, 100 mg/kg of niclosamide could suppress the growth of the relatively slow-growing tumor (CRC039) to the same level
  • niclosamide was confirmed to inhibit the growth of human CRCs in NOD/SCID mice
  • niclosamide can inhibit Wnt pathway activation in CRC
  • The mechanism of action of the niclosamide in our studies is thought to be through internalization of Fzd1 and downregulation of Wnt pathway intermediaries
  • Recently, Jin et al. (26) reported that niclosamide inhibited the NF-κB pathway and increased reactive oxygen species levels to induce apoptosis in AML cells. In contrast, we did not observe any inhibitory effect of niclosamide on NF-κB signaling in our CRC model
  • One potential concern for the use of niclosamide as an anticancer therapy is the poor absorption of this drug
  • we required higher doses (100 ~ 200 mg/kg body weight) of niclosamide in order to demonstrate significant inhibition of tumor growth in NOD/SCID mice
  • niclosamide concentrations in tumor tissue showed good correlation with those in plasma, suggesting the efficient distribution of niclosamide from blood to tumor tissue
  • we observed downregulation of Dvl2 and ß-catenin cytosolic expression in niclosamide-treated tumor cells in vivo
  • oral administration of niclosamide does result in sufficient distribution of the drug into tumor tissue, to prove a prolonged inhibitory effect on Wnt/ß-catenin signaling, resulting in tumor growth inhibition
  • The Wnt signaling pathway, fundamental to embryonic tissue patterning, is also activated in stem-like cells
  • The canonical Wnt pathway is activated in approximately 80% of sporadic CRC primarily due to mutations in the APC gene
  • recent observations reveal that Wnt ligands or inhibitors may affect the growth and survival of colon cancer cells in spite of the presence of APC or CTNNB1 mutations
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    Niclosamide found to inhibit Wnt/B-catenin signaling pathway, and thus promotion of apoptosis, in colorectal cancer cells in Vivo study.  It was also found to augment chemotherapeutic.
Nathan Goodyear

The SARS-CoV-2 Spike Protein Activates the Epidermal Growth Factor Receptor-Mediated Si... - 0 views

  • we wanted to investigate if other molecular targets and pathways may be used by SARS-CoV-2. We investigated the possibility of the spike 1 S protein and its receptor-binding domain (RBD) to target the epidermal growth factor receptor (EGFR) and its downstream signaling pathway in vitro using the lung cancer cell line (A549 cells). Protein expression and phosphorylation were examined upon cell treatment with the recombinant full spike 1 S protein or RBD. We demonstrate for the first time the activation of EGFR by the Spike 1 protein associated with the phosphorylation of the canonical Extracellular signal-regulated kinase1/2 (ERK1/2) and AKT kinases and an increase in survivin expression controlling the survival pathway.
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    WTF!!
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