Skip to main content

Home/ Dr. Goodyear/ Group items tagged Sites

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
Nathan Goodyear

The mineral selenium proves itself as powerful anti-cancer medicine - 0 views

www.naturalnews.com/016446.html

selenium cancer

shared by Nathan Goodyear on 12 May 11 - Cached
  • In a December 1996 article in the Journal of the American Medical Association, Dr. Larry Clark presented evidence that supplemental selenium could reduce cancer death rates by as much as 50%
  • patients receiving selenium had a 67% decrease in cancer of the prostate, a 58 percent decrease in colon or rectal cancer and a 45% decrease in lung cancer
  • An article in the Journal of the American Medical Association (JAMA) by Clark et al. (1996) showed that 200 mcg of supplemental selenium a day reduced overall cancer mortality by 50% in humans compared to a placebo group not receiving supplemental selenium
  • ...10 more annotations...
  • In a recent five-year study of nearly 30,000 rural Chinese people, researchers from the NCI found that daily doses of these three nutrients reduced cancer deaths by 13%.
  • In a study in Cancer Letters (Evangelou et al. 1997), animals with malignant tumors given high doses of vitamins C and E and selenium manifested a significant prolongation of the mean survival time. Complete remission of tumors developed in 16.8% of the animals
  • cities and states with high selenium content in the soil also had significantly lower rates of cancer, especially of the digestive and urinary systems.
  • In one study of hundreds of men, a daily intake of 200 micrograms of selenium cut the incidence of prostate cancer by 60 percent.
  • The statistics for breast cancer are particularly striking. "The higher the selenium, the lower the breast cancer
  • In Yugoslavia, scientists studied 33 patients with breast cancer. These women had selenium levels in their bloodstream only half those of healthy volunteers.
  • The overall reduction in cancer incidence was 37% in the selenium-supplemented group; a 50% reduction in cancer mortality was observed over a 10-year period
  • The following are the site-specific reductions in cancer incidence observed in the study: colon-rectal cancers (58%), lung cancer (46%), and prostate cancer (63%)
  • A selenium deficiency appears to increase the risk of prostate cancer fourfold to fivefold
  • It was determined that, as the male population ages, selenium levels decrease, paralleling an increase in prostate cancer
  • Nathan Goodyear on 12 May 11
     
    exhaustive discussion selenium deficiency and increased cancer risk
Nathan Goodyear

Splenda alters gut microflora and... [J Toxicol Environ Health A. 2008] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...entrez

splenda sucralose dysbiosis gut microflora bacteria

shared by Nathan Goodyear on 20 Sep 11 - No Cached
  • Nathan Goodyear on 20 Sep 11
     
    splenda shown to alter gut bacterial balance
Nathan Goodyear

Interaction of 5-methyltetrahydrofolate and tetrah... [Am J Physiol Heart Circ Physiol.... - 0 views

www.ncbi.nlm.nih.gov/...12003825

5-methyltetrahydrofolate tetrahydropbiopterin NO endothelial vascular function cardiovascular disease

shared by Nathan Goodyear on 29 Apr 11 - No Cached
  • We demonstrate that 5-methyltetrahydrofolate binds the active site of nitric oxide synthase and mimics the orientation of tetrahydrobiopterin
  • 5-methyltetrahydrofolate attenuates superoxide production (induced by inhibition of tetrahydrobiopterin synthesis) and improves endothelial function
  • e suggest that 5-methyltetrahydrofolate directly interacts with nitric oxide synthase to promote nitric oxide (vs. superoxide) production and improve endothelial function
  • ...1 more annotation...
  • 5-Methyltetrahydrofolate may represent an important strategy for intervention aimed at improving tetrahydrobiopterin bioavailability.
  • Nathan Goodyear on 29 Apr 11
     
    5-methyltetrahydrofolate promotes NO synthase and improves endothelial vascular function;  proposed as way to increase tetrahydropbiopterin
Nathan Goodyear

Marathons damage the hearts of less fit runners for up to three months - - Heart and St... - 0 views

www.heartandstroke.nb.ca/...content2.aspx

endurance training running runners marathon marathons heart health CVD exercise

shared by Nathan Goodyear on 09 Jan 15 - No Cached
  • Nathan Goodyear on 09 Jan 15
     
    Summary of 2010 report on marathons and the heart.  Less fit runners can do significant damage to the heart i.e. fibrosis compared to fit runners.  V02 max is a good way to assess aerobic endurance and differentiate between the two.  Dr Larose showed via MRI that it can take 3 months for the heart to recover.
Nathan Goodyear

Exercise-induced right ventricular dysfunction and structural remodelling in endurance ... - 0 views

eurheartj.oxfordjournals.org/...998

endurance athletes training heart health injury

shared by Nathan Goodyear on 09 Jan 15 - No Cached
  • In a cohort of well-trained athletes, we demonstrated that intense endurance exercise causes an acute reduction in RV function that increases with race duration and correlates with increases in biomarkers of myocardial injury
  • no relationship between LV function and biomarker levels
  • focal gadolinium enhancement and increased RV remodelling were more prevalent in those athletes with a longer history of competitive sport, suggesting that repetitive ultra-endurance exercise may lead to more extensive RV change and possible myocardial fibrosis
  • ...22 more annotations...
  • he cardiac impact of both acute and cumulative exercise is greatest on the RV.
  • Greater reductions in RV function occurred in those athletes competing for a longer duration, suggesting that the heart has a finite capacity to maintain the increased work demands of exercise
  • cardiac injury is greatest in the least trained
  • Previous investigators have documented reductions in RV function in less trained subjects over the marathon distance
  • We enrolled elite and subelite athletes and found a significant association between fitness (VO2max) and the reduction in post-race RVEF
  • Even after many years of detraining, cardiac dilation may not completely regress in elite athletes
  • The focus on well-trained athletes may be of particular relevance, given that they perform exercise of highest intensity and duration most frequently, and, thus, may be at a greater risk of cumulative injury.
  • The lack of correlation between increases in troponin and changes in LV function seen in this study has been previously interpreted as evidence that post-exercise elevations in cardiac biomarkers are benign.
  • a significant correlation between changes in RVEF and post-race biomarker levels and this relationship was even stronger in the athletes who completed the race of longest duration, the ultra-triathlon
  • The correlations with RVEF, but not LVEF, provide further evidence of the differential effects of intense exercise on RV and LV function
  • BNP release during intense exercise is associated with greater relative increases in RV systolic pressures, but not LV pressures
  • BNP may provide a measure of both acute RV load and the resultant fatigue which occurs when this load is sustained
  • It has been demonstrated that ventricular load increases with exercise intensity and is greater for the RV than the LV,29 thus potentially explaining why the RV is more susceptible to fatigue after prolonged exercise.
  • This study demonstrates, for the first time, an association between endurance exercise of increasing duration and structural, functional, and biochemical markers of cardiac dysfunction in highly trained athletes
  • Functional abnormalities were confined to the RV and were largely reversible 1 week following the event
  • there remained a significant minority of athletes in whom there was evidence of myocardial fibrosis in the interventricular septum
  • RV abnormalities may be acquired through cumulative bouts of intense exercise and provides direction for prospective investigations aimed at elucidating whether extreme exercise may promote arrhythmias in some athletes.
  • the acute injury and chronic remodelling of the myocardium both disproportionately affect the RV and it remains possible that the two are linked.
  • focal DGE was confined to the interventricular septum and commonly at the site of RV attachment
  • emerging evidence that intense endurance exercise may be associated with an excess in arrhythmic disorders, the mechanisms for which remain unexplained
  • RVEF (and not LVEF) was reduced in athletes with complex ventricular arrhythmias when compared with healthy athletes and non-athletes without arrhythmias
  • it is premature to conclude that these changes may represent a proarrhythmic substrate
  • Nathan Goodyear on 09 Jan 15
     
    Study finds endurance racing results in reduce Right ventricle ejection fraction even in elite athletes.  This post-race RVEF reduction is associated with VO2max.
Nathan Goodyear

Differential Effects of Dehydroepiandrosterone and Testosterone in Prostate and Colon C... - 0 views

press.endocrine.org/...en.2012-2249

testosterone prostate colon colon cancer cancer NGF nerve growth factor dhea dehydroepiandrosterone

shared by Nathan Goodyear on 19 Nov 14 - No Cached
  • Several studies indicate that DHEA may enhance cancer-promoting activities in several prostate cancer cell lines acting as agonist or antagonist for the intracellular AR
  • the estrogenic metabolites of DHEA, 5a-androstane-3b, 17b-diol (3b-Adiol) and E2 bind to estrogen receptors but not to AR
  • no specific receptor has been identified for DHEA
  • ...16 more annotations...
  • Different members of neurotrophins are expressed during cancer progression, suggesting their involvement in cell proliferation, anoikis protection, and malignancy
  • Regulation of the apoptotic machinery in prostate and colon cancer cells by testosterone occurs rapidly and is initiated at the plasma membrane level through specific membrane-binding sites not involving the classical cytoplasmic AR
  • testosterone exerts potent regulatory effects on prostate and colon cancer cell apoptosis
  • Testosterone increased cell death in a dose-dependent manner
  • testosterone antagonizes the prosurvival effects of DHEA in neuronal cells, blocking its binding to NGF receptors
  • treatment of cells with DHEA exerted a strong antiapoptotic effect,
  • Androgens hold a central role in prostate and colon cancer biology
  • elevated levels of DHEA or its sulfate ester DHEA-sulfate in young adults are associated to low incidence of androgen-dependent tumors
  • DHEA may play a protective role in young prostate
  • The decline of DHEA with aging may contribute to prostate cancer progression associated with advanced age
  • DHEA is an effective antiapoptotic factor, reversing the serum deprivation-induced apoptosis in prostate cancer cells (DU145 and LNCaP cell lines) as well as in colon cancer cells
  • NGF appears to exert similar antiapoptotic actions in both prostate and color cancer cells
  • exposure of prostate DU145 and colon Caco2 cancer cells to testosterone totally blocked the protective effects of both DHEA and NGF. These findings suggest that testosterone acts as an antagonist of DHEA and NGF
  • These findings support the hypothesis that testosterone may inhibit cancer cell growth by antagonizing the proliferative, antiapoptotic effects of endogenous factors, such as DHEA or NGF, in the case of prostate and colon cancer cells
  • intratumor hormonal microenvironment may play a critical role in tumor progression.
  • The paracrine interactions of androgens with locally produced NGF may define tumor cell fate
  • Nathan Goodyear on 19 Nov 14
     
    Full article of previously posted abstract.  Cancers are unique.  Not all cancers are alike.  Whether they are tissue specific or not, cancers are unique.  This article describes the uniqueness of DHEA and Testosterone cancer, with particular attention to colon.
Nathan Goodyear

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

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

cancer DCA

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

Low serum albumin levels and liver metastasis are powerful prognostic markers for survi... - 0 views

onlinelibrary.wiley.com/...cncr.22300

albumin cancer liver metastasis

shared by Nathan Goodyear on 09 Jul 18 - No Cached
  • poor PS,8-10 the presence of liver metastases,7, 9, 10 and elevated LDH levels10 were independent prognostic factors
  • lymphopenia (HR of, 1.89; P = .04) and hypoalbuminemia (HR of 2.7; P < .0001) were independent prognostic factors for overall survival
  • lymphopenia in cancer patients remain unclear and may reflect in part poor nutrition
  • ...2 more annotations...
  • may result in part from the destruction of lymphocytes by the tumor and/or an impaired differentiation of lymphocytes progenitors
  • presence of liver metastasis (HR of, 2.27; P = .0003) and hypoalbuminemia were the 2 most powerful adverse prognostic factors
  • Nathan Goodyear on 09 Jul 18
     
    study finds that lympohopenia and low albumin was associated with the worse prognosis in 317 patients with liver mets with unknown primary cancer. 
Nathan Goodyear

A Combined Preclinical Therapy of Cannabinoids and Temozolomide against Glioma | Molecu... - 0 views

mct.aacrjournals.org/...90.long

cancer THC medical marijuana glioblastoma CBD

shared by Nathan Goodyear on 18 Sep 18 - No Cached
  • Δ9-Tetrahydrocannabinol (THC; Supplementary Fig. 1), the main active component of the hemp plant Cannabis sativa
  • CB1, abundantly expressed in the brain and at many peripheral sites
  • CB2, expressed in the immune system and also present in some neuron subpopulations and glioma cells
  • ...3 more annotations...
  • antitumoral agents
  • Aside from THC, C. sativa produces approximately 70 other cannabinoids, although, unlike THC, many of them exhibit little affinity for CB receptors (10, 20). Of interest, at least one of these components, namely, cannabinol (CBD; Supplementary Fig. 1), has been shown to reduce the growth of different types of tumor xenografts including gliomas
  • the combined administration of THC and CBD is being therapeutically explored (10, 20, 26), although its effects on the proliferation and survival of cancer cells have only been analyzed in vitro
  • Nathan Goodyear on 18 Sep 18
     
    THC found to augment chemotherapy in the glioblastoma cell culture study.
Nathan Goodyear

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

www.ncbi.nlm.nih.gov/...PMC4287931

ivermectin cancer WTF Selamectin

shared by Nathan Goodyear on 19 Mar 18 - No Cached
  • 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
  • ...31 more annotations...
  • 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
  • Nathan Goodyear on 19 Mar 18
     
    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

Plasma 25-hydroxyvitamin D concentration and subsequent risk of total and site specific... - 0 views

www.bmj.com/bmj.k671

vitamin D cancer

shared by Nathan Goodyear on 15 Mar 18 - No Cached
  • Nathan Goodyear on 15 Mar 18
     
    New Study from BMJ finds that higher vitamin D levels are associated with a decreased relative risk for total cancer.  The most significant inverse association was found with risk of liver cancer. The study divided the vitamin D levels into quartiles.
Nathan Goodyear

American Journal of Obstetrics & Gynecology Home Page - 0 views

www.ajog.org/...fulltext

"Vaginal mesh" immune system

shared by Nathan Goodyear on 31 Aug 18 - No Cached
  • M1 macrophages are characterized by the secretion of reactive oxygen species and proinflammatory cytokines and chemokines and can be identified via the cell surface marker CD86
  • M2 macrophages secrete growth factors and antiinflammatory immune modulators and can be identified by the cell surface marker CD206
  • an overzealous M2 response can also lead to excess tissue deposition and fibrosis
  • ...14 more annotations...
  • Studies of similar meshes that are used in hernia repair have demonstrated that all polypropylene meshes induce a prolonged inflammatory response at the site of implantation
  • the long-term presence of activated inflammatory cells, such as macrophages at the mesh tissue interface, can impact negatively the ability of the mesh to function as intended.
  • All M1 proinflammatory and M2 proremodeling cytokines and chemokines were increased in mesh explants as compared with nonmesh tissue (Table 3Table 3), which indicated a robust, active, and ongoing host response to polypropylene long after implantation
  • Comparison of the ratio of the M2 proremodeling cytokines (IL-10+IL-4) with the M1 proinflammatory cytokines (TNF-α+IL-12p70) revealed a decrease in mesh explants as compared with controls (P = .003), which indicated a shift towards a proinflammatory profile.
  • Mesh explants contained a higher number of total cells/×200 field when compared with controls (682.46 ± 142.61 cells vs 441.63 ± 126.13 cells; P < .001) and a lower ratio of M2:M1 macrophages (0.260 ± 0.161 cells vs 1.772 ± 1.919; P = .001), which supported an ongoing proinflammatory response.
  • the host response was proportional to the amount of material in contact with the host
  • A persistent foreign body response was observed in mesh-tissue complexes that were excised from women who required surgical excision of mesh months to years after mesh implantation
  • The host response was characterized by a predominance of macrophages with an increase in both proinflammatory and proremodeling cytokines/chemokines along with increased tissue degradation, as evidenced by increased MMP-2 and -9
  • Mesh-tissue complexes removed for mesh exposure had increased pro–MMP-9 that indicated a proinflammatory and tissue destruction–type response
  • The presence of macrophages, elevated cytokines, chemokines, and MMPs in tissue-mesh complexes that were excised from patients with exposure or pain suggests that polypropylene mesh elicits an ongoing host inflammatory response
  • In the presence of a permanent foreign body, the implant is surrounded with a fibrotic capsule because it cannot be degraded
  • For hernia meshes, if the fibers are too close (<1 mm), the fibrotic response to neighboring fibers overlaps, or “bridges,” and results in “bridging fibrosis” or encapsulation of the mesh
  • Gynemesh PS has a highly unstable geometry when loaded that resulted in pore collapse and increasing stiffness of the product
  • mesh shrinkage (50-70%) has been described to occur after transvaginal insertion of prolapse meshes
  • Nathan Goodyear on 31 Aug 18
     
    Mesh and the abnormal immune response.
zoran de

Buy Innoveda Arthrella Online - Nutritional Supplements for Osteoarthritis & Joint Pain - 0 views

www.charakusa.com/...arthrella

Nutritional Supplements Dietary Natural Treatments Herbal Health Supplement Treatment Arthritis For What is osteoarthritis Medicine the of Ayurvedic Medicines Organic

shared by zoran de on 06 Oct 16 - No Cached
  • zoran de on 06 Oct 16
     
    Arthrella is a rich combination of joint support phytochemicals. Arthrella combines the extracts of 4 herbs which offer support to the bones and the joints and help regulate healthy active joints and muscles. Arthrella helps in promoting normal structure and functioning of musculoskeletal system Social Media Site https://www.youtube.com/user/CharakPharma https://www.facebook.com/CharakPharma https://twitter.com/charak_pharma https://plus.google.com/+charakpharma https://www.linkedin.com/company/charak-pharma-pvt.-ltd. https://www.pinterest.com/OTCSupermarket/charak-pharma/ https://plus.google.com/u/0/communities/112690639266834894016 CONTACT US Charak Pharma (USA) inc 303-5th Avenue, Suite # 1007 New York, NY 10016 United States Email : enquiry@charakusa.com info@charakusa.com 91 22 33016734 Google My Business Location- http://listings.findthecompany.com/l/474216049/Charak-Pharma-Usa-Inc-in-New-York-NY Buy Innoveda Arthrella Online - Shop, Cart & checkout Page Url Shop - http://www.charakusa.com/shop/ Add to Card - http://www.charakusa.com/cart/ Proceed to Checkout- http://www.charakusa.com/checkout/
Nathan Goodyear

Immune responses to malignancies - 0 views

www.ncbi.nlm.nih.gov/...PMC3721350

cancer immune system

shared by Nathan Goodyear on 18 Apr 18 - No Cached
  • increased densities of T-cell infiltrates with a high proportion of CD8+ T cells within primary colorectal carcinomas were associated with a significant protection against tumor recurrence
  • coexpression of genes mediating cytotoxicity and TH1 adaptive immune responses accurately predicted survival in patients with colorectal carcinoma independently of the metastatic status.
  • tumor-specific cytolytic T lymphocytes (CTLs)
  • ...10 more annotations...
  • tumor-associated antigens (TAs)
  • Proinflammatory cytokines secreted by inflammatory cells can contribute to tumor progression, and soluble factors produced by the tumor in response to nonspecific or tumor-specific signals, such as prostaglandin E2 (PGE2), adenosine, or TGF-β, downregulate functions of immune cells
  • they are largely ineffective in arresting tumor growth, although they can proliferate and mediate antitumor cytotoxicity on their removal from the tumor bed and ex vivo IL-2 activation.42
  • DCs (HLA-DR+CD86+CD80+CD14−) are nature’s best APCs
  • They are a common component of tumor immune infiltrates and are responsible for the uptake, processing, and cross-presentation of TAs to naive or memory T cells, thus playing a crucial role in the generation of tumor-specific effector T cells
  • DCs control the induction of Treg cells. In patients with cancer, cellular interactions between antigen-presenting DCs and T cells lead to expansion and accumulation of Treg cells at the tumor site and in the periphery
  • NK cells (CD3−CD56+CD16+), which mediate innate immunity and contain both perforin-rich and granzyme-rich granules, are well equipped to mediate lysis of tumor cells
  • B cells (CD19+, CD20+) are also rare in most human tumors, with the exception of breast cancer and melanoma
  • The initial acute inflammation involving the recruitment and influx of antitumor effector cells is replaced by chronic inflammation in later stages of tumor progression
  • Tissue hypoxia plays a major role in shaping the nature of immune infiltrates in tumors
  • Nathan Goodyear on 18 Apr 18
     
    Another great review of the immune system during different stages of carcinogenesis; how the cancer manipulates the immue system to cloak itself from the immune system.
Nathan Goodyear

Clinical experience with intravenous administration of ascorbic acid: achievable levels... - 0 views

www.ncbi.nlm.nih.gov/...PMC3751545

IV vitamin C dosing ascorbic acid inflammation disease cancer IV vitamin C intravenous vitamin C IV intravenous vitamin C vitamin C CRP therapy treatment alternative

shared by Nathan Goodyear on 26 Aug 14 - No Cached
  • Patients with higher tumor markers are likely to have higher tumor burden, higher oxidative stress and, therefore, are more likely to have lower post IVC plasma levels.
  • Our data also showed that cancer patients with metastasis tend to have lower post-IVC vitamin C levels than those without metastasis
  • Lower peak plasma concentrations are obtained in cancer patients than in healthy subjects. Cancer patients who are deficient in vitamin C prior to therapy tend to achieve lower plasma levels post infusion.
  • ...25 more annotations...
  • Patients with higher inflammation or tumor burdens, as measured by CRP levels or tumor antigen levels, tend to show lower peak plasma ascorbate levels after IVC.
  • Patients with metastatic tumors tend to achieve lower post infusion plasma ascorbate levels than those with localized tumors.
  • Meta-analyses of clinical studies involving cancer and vitamins also conclude that antioxidant supplementation does not interfere with the efficacy of chemotherapeutic regiments
  • Most of the prostate cancer patients studied, 75±19% (95% confidence), showed reductions in PSA levels during the course of their IVC therapy
  • Laboratory studies suggest that, at high concentrations, ascorbate does not interfere with chemotherapy or irradiation and may enhance efficacy in some situations
  • Cameron and Pauling observed fourfold survival times in terminal cancer patients treated with intravenous ascorbate infusions followed by oral supplementation
  • The inflammatory microenvironment of cancer cells leads to increasing oxidative stress, which apparently depletes vitamin C, resulting in lower plasma ascorbate concentrations in blood samples post IVC infusion. Another explanation for this finding may be that cancers are themselves more metabolically active in their uptake of vitamin C, causing subjects to absorb more of the vitamin, and as a results show lower plasma ascorbate concentrations in blood post IVC infusion.
  • patients with severely elevated CRP levels attain plasma ascorbate concentrations after IVC infusions that are only 65% of those attained for subjects with normal CRP levels
  • The finding of decreased plasma ascorbate levels in cancer patients may relate to the molecular structure of ascorbic acid; in particular, the similarity of its oxidized form, dihydroascorbic acid, to glucose
  • Since tumor have increased requirement for glucose [67], transport of dehydroascorbate into the cancer cells via glucose transport molecules and ascorbate through sodium-dependent transporter may be elevated
  • Increased accumulation of ascorbic acid in the tumor site was supported by measurements of the level of ascorbic acid in tumors in animal experiments
  • patients with advanced malignancies may have lower level of ascorbic acid in tissue, creating a higher demand for the vitamin C
  • IVC therapy appears to reduce CRP levels in cancer patients.
  • CRP concentrations directly correlate with disease activity in many cases and can contribute to disease progression through a range of pro-inflammatory properties.
  • Being an exquisitely sensitive marker of systemic inflammation and tissue damage, CRP is very useful in screening for organic disease and monitoring treatment responses
  • ncreases in CRP concentrations have been associated with poorer prognosis of survival in cancer patients, particularly with advance disease independent of tumor stage
  • Regarding inflammation, 73±13% of subjects (95% confidence) showed a reduction in CRP levels during therapy. This was an even more dramatic 86±13% (95% confidence) in subjects who started therapy with CRP levels above 10 mg/L
  • patients treated by IVC with follow-up several year showed that suppression of inflammation in cancer patients by high-dose IVC is feasible and potentially beneficial
  • Inflammation is a marker of high cancer risk, and poor treatment outcome
  • The subjects with highly elevated CRP concentrations have a three-fold elevation “all-cause” mortality risk and a twenty-eight fold increase in cancer mortality risk
  • cancer patients may need higher doses to achieve a given plasma concentration.
  • patients with lower vitamin C levels may see more distribution of intravenously administered ascorbate into tissues and thus attain less in plasma.
  • When treating patients with IVC, the first treatment likely serves to replenish depleted tissue stores, if those subjects were vitamin C deficient at the beginning of the treatment. Then, in subsequent treatments, with increasing doses, higher plasma concentrations can be attained. On-going treatments serve to progressively reduce oxidative stress in cancer patients.
  • large doses given intravenously may result in maximum plasma concentrations of roughly 30 mM, a level that has been shown to be sufficient for preferential cytotoxicity against cancer cells
  • oral intake of vitamin C exceeded 200 mg administered once daily, it was difficult to increase plasma and tissue concentrations above roughly 200 μM.
  • Nathan Goodyear on 26 Aug 14
     
    Great review on the use of IV vitamin C in cancer and to reduce inflammation.  The article does a great job of discussing the mechanism of vitamin C therapy in cancer as well as the proposed reasons for low vitamin C in cancer patients.  The study also highlights the obstacles to rise in vitamin C levels post IV vitamin C in cancer patients.
Nathan Goodyear

The Risk of Fluoroquinolone-induced Tendinopathy and Tendon Rupture - 0 views

www.ncbi.nlm.nih.gov/...PMC2921747

flouroquinolones ciprofloxacin levoquin tendinitis tendinopathy Tendon rupture

shared by Nathan Goodyear on 02 Aug 17 - No Cached
  • Achilles tendinitis or rupture is among the most serious side effects associated with FQ use
  • The large body of data provided by clinical reports, histopathological examination, and experimental studies provides cogent evidence supporting a direct link between FQ use and tendonitis/tendon rupture
  • Risk factors associated with FQ-induced tendon disorders include age greater than 60 years, corticosteroid therapy, renal failure, diabetes mellitus, and a history of musculoskeletal disorders
  • ...17 more annotations...
  • The average age of FQ-induced tendinopathy is 64 years, with a male-to-female ratio of 2:1, and a 27-percent incidence of bilateral involvement
  • Although more than 95 percent of cases of tendinitis/rupture secondary to FQ involve the Achilles tendon, other reported sites of tendon involvement include the quadriceps, peroneus brevis, and rotator cuff
  • FQs demonstrate a 3.8-fold greater risk for development of Achilles tendinitis/rupture
  • a large population-based case control analysis, patients treated with FQs exhibited a substantially increased risk of developing tendon disorders overall (1.7-fold), tendon rupture (1.3-fold), and ATR (4.1-fold)
  • patients taking FQs with concurrent exposure to corticosteroids were found to experience a compounding effect on the risk of tendon rupture, specifically a 46-fold greater predisposition
  • Some authors have recommended that patients with a history of Achilles tendinitis and advanced age should not be prescribed FQ antibiotics
  • Approximately 50 percent of patients will recover within 30 days, with 25 percent of patients having symptoms persistent for longer than two months
  • The mean latency period between the start of FQ treatment and occurrence of tendinopathy has been reported to be a few hours to months, with a median onset of 6 days
  • The exact pathophysiology of FQ-induced tendinopathy remains elusive
  • it is possible that FQs have a direct cytotoxic effect on enzymes found in mammalian musculoskeletal tissue
  • It has been theorized that FQs disproportionately affect human tendons that have a limited capacity for repair, such as in older patients or structural compromise (i.e., pre-existing tendinopathy or trauma)
  • histopathological findings are similar to those observed in overuse conditions in athletes
  • Treatment with a FQ should be discontinued and physical therapy initiated
  • treatment should include rest and decreasing the physical load on the tendon.
  • Approximately 85 percent of patients present in less than one month
  • Because rupture can occur even late in the course of treatment or after discontinuation of FQ use, patients receiving a FQ should be counseled to seek medical attention immediately if symptoms, such as redness, pain, swelling, and stiffness, develop
  • FQs should be used cautiously in patients with risk factors associated with tendinitis, such as advanced age, history of tendon rupture, corticosteroid use, and/or acute or chronic renal dysfunction
  • Nathan Goodyear on 02 Aug 17
     
    Great review of the link between flouroquinolones and Tendinitis and Tendon rupture.  Yes, there is a direct link.
Nathan Goodyear

Lipid Peroxidation: Production, Metabolism, and Signaling Mechanisms of Malondialdehyde... - 0 views

www.hindawi.com/...360438

MDA malondialdehyde peroxidation oxidative stress free radicals

shared by Nathan Goodyear on 05 Dec 17 - No Cached
  • Hydroxyl radicals cause oxidative damage to cells because they unspecifically attack biomolecules [22] located less than a few nanometres from its site of generation and are involved in cellular disorders such as neurodegeneration [23, 24], cardiovascular disease [25], and cancer [26, 27].
  • It is generally assumed that in biological systems is formed through redox cycling by Fenton reaction, where free iron (Fe2+) reacts with hydrogen peroxide (H2O2) and the Haber-Weiss reaction that results in the production of Fe2+ when superoxide reacts with ferric iron (Fe3+)
  • other transition-metal including Cu, Ni, Co, and V can be responsible for formation in living cells
  • ...20 more annotations...
  • The hydroperoxyl radical () plays an important role in the chemistry of lipid peroxidation
  • The is a much stronger oxidant than superoxide anion-radical
  • Lipid peroxidation can be described generally as a process under which oxidants such as free radicals or nonradical species attack lipids containing carbon-carbon double bond(s), especially polyunsaturated fatty acids (PUFAs) that involve hydrogen abstraction from a carbon, with oxygen insertion resulting in lipid peroxyl radicals and hydroperoxides as described previously
  • under medium or high lipid peroxidation rates (toxic conditions) the extent of oxidative damage overwhelms repair capacity, and the cells induce apoptosis or necrosis programmed cell death
  • The overall process of lipid peroxidation consists of three steps: initiation, propagation, and termination
  • Once lipid peroxidation is initiated, a propagation of chain reactions will take place until termination products are produced.
  • The main primary products of lipid peroxidation are lipid hydroperoxides (LOOH)
  • Among the many different aldehydes which can be formed as secondary products during lipid peroxidation, malondialdehyde (MDA), propanal, hexanal, and 4-hydroxynonenal (4-HNE) have been extensively studied
  • MDA has been widely used for many years as a convenient biomarker for lipid peroxidation of omega-3 and omega-6 fatty acids because of its facile reaction with thiobarbituric acid (TBA)
  • MDA is one of the most popular and reliable markers that determine oxidative stress in clinical situations [53], and due to MDA’s high reactivity and toxicity underlying the fact that this molecule is very relevant to biomedical research community
  • 4-HNE is considered as “second toxic messengers of free radicals,” and also as “one of the most physiologically active lipid peroxides,” “one of major generators of oxidative stress,” “a chemotactic aldehydic end-product of lipid peroxidation,” and a “major lipid peroxidation product”
  • MDA is an end-product generated by decomposition of arachidonic acid and larger PUFAs
  • Identifying in vivo MDA production and its role in biology is important as indicated by the extensive literature on the compound (over 15 800 articles in the PubMed database using the keyword “malondialdehyde lipid peroxidation” in December 2013)
  • MDA reactivity is pH-dependent
  • When pH decreases MDA exists as beta-hydroxyacrolein and its reactivity increases
  • MAA adducts are shown to be highly immunogenic [177–181]. MDA adducts are biologically important because they can participate in secondary deleterious reactions (e.g., crosslinking) by promoting intramolecular or intermolecular protein/DNA crosslinking that may induce profound alteration in the biochemical properties of biomolecules and accumulate during aging and in chronic diseases
  • MDA is an important contributor to DNA damage and mutation
  • This MDA-induced DNA alteration may contribute significantly to cancer and other genetic diseases.
  • Dietary intake of certain antioxidants such as vitamins was associated with reduced levels of markers of DNA oxidation (M1dG and 8-oxodG) measured in peripheral white blood cells of healthy subjects, which could contribute to the protective role of vitamins on cancer risk
  • 4-HNE is an extraordinarily reactive compound
  • Nathan Goodyear on 05 Dec 17
     
    Great review of lipid peroxidation
Nathan Goodyear

Induction of metastasis, cancer stem cell phenotype, and oncogenic metabolism in cancer... - 0 views

www.ncbi.nlm.nih.gov/...PMC5282724

EMT TME metastasis cancer stem cells cancer MMP2 Notch MMP-9 MMP-2 radioresistance Hedgehog CSC MMP9 Snail HIF-1alpha tumor microenvironment epithelial to mesenchymal transition TGF-beta radiation

shared by Nathan Goodyear on 09 Feb 21 - No Cached
  • More than half of cancer patients are treated with IR at some point during their treatment
  • fractionation schedule is the delivery of 1.8–2.0 Gy per day, five days per week
  • Nuclear DNA is the primary target of IR; it causes DNA damage (genotoxic stress) by direct DNA ionization
  • ...121 more annotations...
  • IR also indirectly induces DNA damage by stimulating reactive oxygen species (ROS) production
  • IR is known to induce EMT in vitro
  • p53 is activated in response to IR-induced DNA damage
  • IR paradoxically also promotes tumour recurrence and metastasis
  • DNA double-strand breaks (DSBs)
  • cancer cells undergoing EMT acquire invasive and metastatic properties
  • changes in the tumour microenvironment (TME)
  • IR seems to induce EMT and CSC phenotypes by regulating cellular metabolism
  • EMT, stemness, and oncogenic metabolism are known to be associated with resistance to radiotherapy and chemotherapy
  • Hanahan and Weinberg proposed ten hallmarks of cancer that alter cell physiology to enhance malignant growth: 1) sustained proliferation, 2) evasion of growth suppression, 3) cell death resistance, 4) replicative immortality, 5) evasion of immune destruction, 6) tumour-promoting inflammation, 7) activation of invasion and metastasis, 8) induction of angiogenesis, 9) genome instability, and 10) alteration of metabolism
  • EMT is a developmental process that plays critical roles in embryogenesis, wound healing, and organ fibrosis
  • IR is known to induce stemness and metabolic alterations in cancer cells
  • transforming growth factor-β [TGF-β], epidermal growth factor [EGF]) and their associated signalling proteins (Wnt, Notch, Hedgehog, nuclear-factor kappa B [NF-κB], extracellular signal-regulated kinase [ERK], and phosphatidylinositol 3-kinase [PI3K]/Akt
  • activate EMT-inducing transcription factors, including Snail/Slug, ZEB1/δEF1, ZEB2/SIP1, Twist1/2, and E12/E47
  • Loss of E-cadherin is considered a hallmark of EMT
  • IR has been shown to induce EMT to enhance the motility and invasiveness of several cancer cells, including those of breast, lung, and liver cancer, and glioma cells
  • IR may increase metastasis in both the primary tumour site and in normal tissues under some circumstance
  • sublethal doses of IR have been shown to enhance the migratory and invasive behaviours of glioma cells
  • ROS are known to play an important role in IR-induced EMT
  • High levels of ROS trigger cell death by causing irreversible damage to cellular components such as proteins, nucleic acids, and lipids, whereas low levels of ROS have been shown to promote tumour progression—including tumour growth, invasion, and metastasis
  • hypoxia-inducible factor-1 (HIF-1) is involved in IR-induced EMT
  • Treatment with the N-acetylcysteine (NAC), a general ROS scavenger, prevents IR-induced EMT, adhesive affinity, and invasion of breast cancer cells
    • Nathan Goodyear
      Nathan Goodyear on 09 Feb 21
       
      NAC for all patients receiving radiation therapy
  • Snail has been shown to play a crucial role in IR-induced EMT, migration, and invasion
  • IR activates the p38 MAPK pathway, which contributes to the induction of Snail expression to promote EMT and invasion
  • NF-κB signalling that promotes cell migration
  • ROS promote EMT to allow cancer cells to avoid hostile environments
  • HIF-1 is a heterodimer composed of an oxygen-sensitive α subunit and a constitutively expressed β subunit.
  • Under normoxia, HIF-1α is rapidly degraded, whereas hypoxia induces stabilisation and accumulation of HIF-1α
  • levels of HIF-1α mRNA are enhanced by activation of the PI3K/Akt/mammalian target of rapamycin (mTOR)
  • IR is known to increase stabilisation and nuclear accumulation of HIF-1α, since hypoxia is a major condition for HIF-1 activation
  • IR induces vascular damage that causes hypoxia
  • ROS is implicated in IR-induced HIF-1 activation
  • IR causes the reoxygenation of hypoxic cancer cells to increase ROS production, which leads to the stabilisation and nuclear accumulation of HIF-1
  • IR increases glucose availability under reoxygenated conditions that promote HIF-1α translation by activating the Akt/mTOR pathway
  • The stabilised HIF-1α then translocates to the nucleus, dimerizes with HIF-1β, and increases gene expression— including the expression of essential EMT regulators such as Snail—to induce EMT, migration, and invasion
  • TGF-β signalling has been shown to play a crucial role in IR-induced EMT
  • AP-1 transcription factor is involved in IR-induced TGF-β1 expression
  • Wnt/β-catenin signalling is also implicated in IR-induced EMT
  • Notch signalling is known to be involved in IR-induced EMT
  • IR also increases Notch-1 expression [99]. Notch-1 is known to induce EMT by upregulating Snail
  • PAI-1 signalling is also implicated in IR-induced Akt activation that increases Snail levels to induce EMT
  • EGFR activation is known to be associated with IR-induced EMT, cell migration, and invasion by activating two downstream pathways: PI3K/Akt and Raf/MEK/ERK
  • ROS and RNS are also implicated in IR-induced EGFR activation
  • IR has also been shown to activate Hedgehog (Hh) signalling to induce EMT
  • IR has been shown to induce Akt activation through several signalling pathways (EGFR, C-X-C chemokine receptor type 4 [CXCR4]/C-X-C motif chemokine 12 [CXCL12], plasminogen activator inhibitor 1 [PAI-1]) and upstream regulators (Bmi1, PTEN) that promote EMT and invasion
  • CSCs possess a capacity for self-renewal, and they can persistently proliferate to initiate tumours upon serial transplantation, thus enabling them to maintain the whole tumour
  • Conventional cancer treatments kill most cancer cells, but CSCs survive due to their resistance to therapy, eventually leading to tumour relapse and metastasis
  • identification of CSCs, three types of markers are utilised: cell surface molecules, transcription factors, and signalling pathway molecules
  • CSCs express distinct and specific surface markers; commonly used ones are CD24, CD34, CD38, CD44, CD90, CD133, and ALDH
  • Transcription factors, including Oct4, Sox2, Nanog, c-Myc, and Klf4,
  • signalling pathways, including those of TGF-β, Wnt, Hedgehog, Notch, platelet-derived growth factor receptor (PDGFR), and JAK/STAT
  • microRNAs (miRNAs), including let-7, miR-22, miR-34a, miR-128, the miR-200 family, and miR-451
  • Non-CSCs can be reprogrammed to become CSCs by epigenetic and genetic changes
  • EMT-inducing transcription factors, such as Snail, ZEB1, and Twist1, are known to confer CSC properties
  • Signalling pathways involved in EMT, including those of TGF-β, Wnt, and Notch, have been shown to play important roles in inducing the CSC phenotype
  • TGF-β1 not only increases EMT markers (Slug, Twist1, β-catenin, N-cadherin), but also upregulates CSC markers (Oct4, Sox2, Nanog, Klf4) in breast and lung cancer cells
  • some CSC subpopulations arise independently of EMT
  • IR has been shown to induce the CSC phenotype in many cancers, including breast, lung, and prostate cancers, as well as melanoma
  • Genotoxic stress due to IR or chemotherapy promotes a CSC-like phenotype by increasing ROS production
  • IR has been shown to induce reprogramming of differentiated cancer cells into CSCs
  • In prostate cancer patients, radiotherapy increases the CD44+ cell population that exhibit CSC properties
  • IR also induces the re-expression of stem cell regulators, such as Sox2, Oct4, Nanog, and Klf4, to promote stemness in cancer cells
  • EMT-inducing transcription factors and signalling pathways, including Snail, STAT3, Notch signalling, the PI3K/Akt pathway, and the MAPK cascade, have been shown to play important roles in IR-induced CSC properties
  • STAT3 directly binds to the Snail promoter and increases Snail transcription, which induces the EMT and CSC phenotypes, in cisplatin-selected resistant cells
  • Other oncogenic metabolic pathways, including glutamine metabolism, the pentose phosphate pathway (PPP), and synthesis of fatty acids and cholesterol, are also enhanced in many cancers
  • metabolic reprogramming
  • HIF-1α, p53, and c-Myc, are known to contribute to oncogenic metabolism
  • metabolic reprogramming
  • tumour cells exhibit high mitochondrial metabolism as well as aerobic glycolysis
  • occurring within the same tumour
  • CSCs can be highly glycolytic-dependent or oxidative phosphorylation (OXPHOS)-dependen
  • mitochondrial function is crucial for maintaining CSC functionality
  • cancer cells depend on mitochondrial metabolism and increase mitochondrial production of ROS that cause pseudo-hypoxia
  • HIF-1 then enhances glycolysis
  • CAFs have defective mitochondria that lead to the cells exhibiting the Warburg effect; the cells take up glucose, and then secrete lactate to 'feed' adjacent cancer cells
  • lactate transporter, monocarboxylate transporter (MCT)
  • nutrient microenvironment
  • Epithelial cancer cells express MCT1, while CAFs express MCT4. MCT4-positive, hypoxic CAFs secrete lactate by aerobic glycolysis, and MCT1-expressing epithelial cancer cells then uptake and use that lactate as a substrate for the tricarboxylic acid (TCA) cycle
  • MCT4-positive cancer cells depend on glycolysis and then efflux lactate, while MCT1-positive cells uptake lactate and rely on OXPHOS
  • metabolic heterogeneity induces a lactate shuttle between hypoxic/glycolytic cells and oxidative/aerobic tumour cells
  • bulk tumour cells exhibit a glycolytic phenotype, with increased conversion of glucose to lactate (and enhanced lactate efflux through MCT4), CSC subsets depend on oxidative phosphorylation; most of the glucose entering the cells is converted to pyruvate to fuel the TCA cycle and the electron transport chain (ETC), thereby increasing mitochondrial ROS production
  • the major fraction of glucose is directed into the pentose phosphate pathway, to produce redox power through the generation of NADPH and ROS scavengers
  • HIF-1α, p53, and c-Myc, are known to contribute to oncogenic metabolism
  • regulatory molecules involved in EMT and CSCs, including Snail, Dlx-2, HIF-1, STAT3, TGF-β, Wnt, and Akt, are implicated in the metabolic reprogramming of cancer cells
  • HIF-1 induces the expression of glycolytic enzymes, including the glucose transporter GLUT, hexokinase, lactate dehydrogenase (LDH), and MCT, resulting in the glycolytic switch
  • HIF-1 represses the expression of pyruvate dehydrogenase kinase (PDK), which inhibits pyruvate dehydrogenase (PDH), thereby inhibiting mitochondrial activity
  • STAT3 has been implicated in EMT-induced metabolic changes as well
  • TGF-β and Wnt play important roles in the metabolic alteration of cancer cells
  • Akt is also implicated in the glycolytic switch and in promoting cancer cell invasiveness
  • EMT, invasion, metastasis, and stemness
  • pyruvate kinase M2 (PKM2), LDH, and pyruvate carboxylase (PC), are implicated in the induction of the EMT and CSC phenotypes
  • decreased activity of PKM2 is known to promote an overall shift in metabolism to aerobic glycolysis
  • LDH catalyses the bidirectional conversion of lactate to pyruvate
  • High levels of LDHA are positively correlated with the expression of EMT and CSC markers
  • IR has been shown to induce metabolic changes in cancer cells
  • IR enhances glycolysis by upregulating GAPDH (a glycolysis enzyme), and it increases lactate production by activating LDHA, which converts pyruvate to lactate
  • IR enhances glycolysis by upregulating GAPDH (a glycolysis enzyme), and it increases lactate production by activating LDHA, which converts pyruvate to lactate
  • IR also elevates MCT1 expression that exports lactate into the extracellular environment, leading to acidification of the tumour microenvironment
  • IR increases intracellular glucose, glucose 6-phosphate, fructose, and products of pyruvate (lactate and alanine), suggesting a role for IR in the upregulation of cytosolic aerobic glycolysis
  • Lactate can activate latent TGF-
  • lactate stimulates cell migration and enhances secretion of hyaluronan from CAF that promote tumour metastasis
  • promote tumour survival, growth, invasion, and metastasis; enhance the stiffness of the ECM; contribute to angiogenesis; and induce inflammation by releasing several growth factors and cytokines (TGF-β, VEGF, hepatocyte growth factor [HGF], PDGF, and stromal cell-derived factor 1 [SDF1]), as well as MMP
  • tumours recruit the host tissue’s blood vessel network to perform four mechanisms: angiogenesis (formation of new vessels), vasculogenesis (de novo formation of blood vessels from endothelial precursor cells), co-option, and modification of existing vessels within tissues.
  • immunosuppressive cells such as tumour-associated macrophages (TAM), MDSCs, and regulatory T cells, and the immunosuppressive cytokines, TGF-β and interleukin-10 (IL-10)
  • immunosuppressive cells such as tumour-associated macrophages (TAM), MDSCs, and regulatory T cells, and the immunosuppressive cytokines, TGF-β and interleukin-10 (IL-10)
  • intrinsic immunogenicity or induce tolerance
  • cancer immunoediting’
  • three phases: 1) elimination, 2) equilibrium, and 3) escape.
  • The third phase, tumour escape, is mediated by antigen loss, immunosuppressive cells (TAM, MDSCs, and regulatory T cells), and immunosuppressive cytokines (TGF-β and IL-10).
  • IR can elicit various changes in the TME, such as CAF activity-mediated ECM remodelling and fibrosis, cycling hypoxia, and an inflammatory response
  • IR activates CAFs to promote the release of growth factors and ECM modulators, including TGF-β and MMP
  • TGF-β directly influences tumour cells and CAFs, promotes tumour immune escape, and activates HIF-1 signalling
    • Nathan Goodyear
      Nathan Goodyear on 09 Feb 21
       
      And now the receipts
  • MMPs degrade ECM that facilitates angiogenesis, tumour cell invasion, and metastasis
    • Nathan Goodyear
      Nathan Goodyear on 09 Feb 21
       
      Receipts and mechanisms
  • IR also promotes MMP-2/9 activation in cancer cells to promote EMT, invasion, and metastasis
  • IR-induced Snail increases MMP-2 expression to promote EMT
  • Radiotherapy has the paradoxical side-effect of increasing tumour aggressiveness
  • IR promotes ROS production in cancer cells, which may induce the activation of oncogenes and the inactivation of tumour suppressors, which further promote oncogenic metabolism
  • Metabolic alterations
  • oncogenic metabolism
  • elicit various changes in the TME
  • Although IR activates an antitumour immune response, this signalling is frequently suppressed by tumour escape mechanisms
  • Nathan Goodyear on 09 Feb 21
     
    Important review article.
« First ‹ Previous 81 - 100 of 110 Next ›
Showing 20▼ items per page