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Nathan Goodyear

Circulating 2-hydroxy and 16-α hydroxy estrone levels and risk of breast canc... - 1 views

www.ncbi.nlm.nih.gov/...PMC2562592

estrogen metabolism menopause post-menopause post menopause estrogen metabolite 2-OH-estrone 16-alpha-OH-estrone 2:16alpha-OH estrone breast cancer risk hormone hormones

shared by Nathan Goodyear on 21 Aug 14 - No Cached
  • 2-OH estrogens bind to the estrogen receptor (ER) with affinity equivalent to or greater than estradiol
  • previous prospective studies have not observed any significant associations with either 2-OH or 16α-OH estrone or the ratio of the two metabolites and breast cancer risk overall.
    • Nathan Goodyear
      Nathan Goodyear on 08 Oct 15
       
      whether that risk is increased or decreased
  • it has been hypothesized that metabolism favoring the 2-OH over the 16α-OH pathway may be inversely associated with breast cancer risk (28).
  • ...24 more annotations...
  • they may act as only weak mitogens (14, 15), or as inhibitors of proliferation
  • No significant associations have been observed between 2-OH estrone and breast cancer risk
  • While 16α-OH estrone binds to the ER with lower affinity than estradiol, it binds covalently (18-20) and once bound, fails to down-regulate the receptor (21). Thus, 16α-OH estrone stimulates cell proliferation in a manner comparable to estradiol in ER+ breast cancer cell lines
  • In this large prospective study of 2-OH and 16α-OH estrone metabolites and breast cancer risk, we did not observe any significant associations overall with either individual metabolite or with the ratio of the two metabolites
  • we observed positive associations with 2-OH estrone and the 2:16α-OH estrone ratio among women with lower BMI and women with ER-/PR-tumors,
  • To date, several epidemiologic studies have examined the association between the 2-OH and 16α-OH estrogen metabolites and breast cancer risk with inconclusive results.
  • circulating estrogen levels have been associated more strongly with ER+/PR+ tumors than with ER-/PR- tumors
  • our results do not support the hypothesis that metabolism favoring the 2-OH estrone pathway is more beneficial to breast cancer risk than that favoring the 16α-OH estrone pathway
  • we observed significant positive associations of both 2-OH estrone and the 2:16α-OH estrone ratio with ER-/PR-tumors
  • Three (30, 32, 33) of four (30-33) studies observed RRs above 1 for the association between 16α-OH estrone and breast cancer risk (range of RRs=1.23-2.47); none of the point estimates was statistically significant though one trend was suggestive
  • based on animal studies, 2-OH estrone and the 2:16α-OH estrone ratio have been hypothesized to be inversely associated with breast cancer risk
  • No significant associations have been observed between 2-OH estrone, 16α-OH estrone, or the 2:16α-OH estrone ratio and breast cancer risk and the direction of the estimates is not consistent across studies.
    • Nathan Goodyear
      Nathan Goodyear on 08 Oct 15
       
      better worded is no consistent, significant associations.   There are some studies that point to the 16 catecholestrogen and increased cancer risk; limited studies show negative effects of 2 catecholestrogens on cancer risk and prospective studies available pretty much dispel the idea that the 2:16 ratio has an risk predictability.
  • we observed a suggestive inverse association with 16α-OH estrone and a significant positive association with the 2:16α-OH estrone ratio among lean women, suggesting possible associations in a low estrogen environment.
  • 16α-OH estrone increases unscheduled DNA synthesis in mouse mammary cells (27) and hence also may be genotoxic
  • Although 2-OH estrogens are capable of redox cycling, the semiquinones and quinones (i.e., the oxidized forms) form stable DNA adducts that are reversible without DNA destruction
  • In our population of PMH nonusers, we observed no associations with ER+/PR+ tumors, but significant positive associations with 2-OH estrone and the 2:16α-OH estrone ratio among women with ER-/PR- tumors
    • Nathan Goodyear
      Nathan Goodyear on 08 Oct 15
       
      one of the few studies to find this association between 2 catecholestrogens and the 2:16 ratio and ER-/PR-tumors
  • Animal and in vitro studies have shown that hydroxy estrogens can induce DNA damage either directly, through the formation of quinones and DNA adducts, or indirectly, through redox cycling and the generation of reactive oxygen species
    • Nathan Goodyear
      Nathan Goodyear on 08 Oct 15
       
      genotoxic via directe DNA adducts and indirectly via ROS; this is in addition to the proliferative effect
  • we observed a significant positive association between the 2:16α-OH estrone ratio and breast cancer risk among lean women
  • No significant associations have been observed with the 2:16α-OH estrone ratio
  • In the Danish study, no associations were observed with either ER+ or ER- tumors among PMH nonusers
  • significant positive associations with 2-OH estrone and the 2:16α-OH estrone ratio were observed among PMH users with ER+, but not ER-, tumors
  • it is possible that the genotoxicity of 2-OH estrone plays a role in hormone receptor negative tumors
  • 4-OH estrogens have a greater estrogenic potential than 2-OH estrogens, given the lower dissociation rate from estrogen receptors compared with estradiol (61), and are potentially more genotoxic since the quinones form unstable adducts, leading to depurination and mutation in vitro and in vivo
  • the balance between the catechol (i.e., 2-OH and 4-OH) and methoxy (i.e., 2-Me and 4-Me) estrogens may impact risk
  • Nathan Goodyear on 21 Aug 14
     
    The risks of estrogen metabolism are not clear cut.  Likely never will be due to the complexity of individual metabolism.  This study found no correlation between 2OH-Estrone and 2OH:16alpha-Estrone and breast cancer risk in ER+/PR+ breast cancer.  Translated: no benefit in breast cancer risk in 2OH-Estrone metabolism or increased 2OH:16alpha estrone metabolism.  There was a positive association between 2OH-Estrone and 2:16alpha-Estrone in women with ER-/PR- tumors and low BMI.
  • anonymous on 28 Oct 15
     
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Nathan Goodyear

Urinary Estrogens and Estrogen Metabolites and Subsequent Risk of Breast Cancer among P... - 0 views

cancerres.aacrjournals.org/...696.full

estrogen metabolites estrogen metabolism ER estrogen receptors ROS hormones cancer breast cancer

shared by Nathan Goodyear on 07 Oct 15 - No Cached
  • both 2- and 4-catechol estrogen metabolites bind to the ER with affinities comparable with estradiol, 4-catechol estrogen metabolites have lower dissociation rates than estradiol and an enhanced ability to upregulate ER-dependent processes
  • 2-catechol estrogen metabolites act as either weak mitogens (39) or weak inhibitors of cell proliferation
  • While 16α-hydroxyestrone binds to the ER with lower affinity than estradiol, it binds covalently (41) and leads to a constitutively activated ER
  • ...15 more annotations...
  • 4-hydroxyestradiol and 16α-hydroxyestrone increasing proliferation and decreasing apoptosis in a manner similar to estradiol; however, these effects were achieved only at concentrations 10-fold higher than estradiol (39). In contrast, 2-hydroxyestradiol did not have substantial proliferative or antiapoptotic effects
  • In our study, the associations with both 2-hydroxyestrone and 16α-hydroxyestrone were nonsignificantly inverse and we did not observe a consistent trend or significant associations between the 2-hydroxyestrone:16α-hydroxyestrone ratio and breast cancer risk
  • Ratios of the 3 hydroxylation pathways were not significantly associated with risk although the 2:16-pathway and 4:16-pathway ratios were suggestively inversely associated
  • a significant inverse association with the ratio of parent estrogens to estrogen metabolites
  • several potentially estrogenic and genotoxic mechanisms
  • Estrogen metabolites also can be genotoxic
  • Catechol estrogens can be oxidized into quinones and induce DNA damage directly through the formation of DNA adducts, or indirectly via redox cycling and generation of reactive oxygen species
  • the oxidized forms of the catechol estrogens differ in their ability to damage DNA through adducts, with oxidized 2-catechols forming stable and reversible DNA adducts and oxidized 4-catechols forming unstable adducts, which lead to depurination and mutations
  • 2- and 4-catechols have been shown to produce reactive oxygen species and induce oxidative DNA damage
  • act independently from the ER
  • 16α-Hydroxyestrone also may be genotoxic
  • While the catechol estrogens have estrogenic and genotoxic potential, the methylated catechol estrogens, which are catechol estrogens with one hydroxyl group methylated, have been hypothesized to lower the risk of breast cancer
  • The suggested mechanisms are indirect, by decreasing circulating levels of catechol estrogens and thereby the opportunity for catechols to exert genotoxic or proliferative effects, or direct, by inhibiting tumor growth and inducing apoptosis
  • the balance between phase I (oxidation) and phase II (methylation) metabolism of estrogen may be important in hormonally related cancer development.
  • Despite the estrogenic and genotoxic potential of many of the estrogen metabolites, we only observed a significantly increased breast cancer risk with one estrogen metabolite, 17-epiestriol, which has particularly strong estrogenic activity and binds to both ERα and ERβ with an affinity comparable with estradiol
  • Nathan Goodyear on 07 Oct 15
     
    review of estrogen metabolites and breast cancer risk in premenopausal women.
Nathan Goodyear

Estrogen Metabolism and Risk of Breast Cancer in Postmenopausal Women - 0 views

www.ncbi.nlm.nih.gov/...PMC3283536

estrogen metabolism estrogen metabolism breast cancer breast cancer

shared by Nathan Goodyear on 14 Oct 13 - No Cached
  • The ratio of the 2-hydroxylation pathway to parent estrogens was associated with a statistically significantly decreased risk of breast cancer
  • In this study, this ratio was more strongly associated with the risk of breast cancer compared with the ratio of 2-hydroxylation pathway to 16-hydroxylation pathway or unconjugated estradiol alone
  • 2-hydroxylation pathway catechols have relatively low affinities for estrogen receptors (4) and are rapidly cleared from circulation
  • ...6 more annotations...
  • In this study, the ratio of the 2-hydroxylation pathway to the 16-hydroxylation pathway was associated with a non-statistically significantly decreased risk of breast cancer
  • In this study, the ratio of catechols to methylated catechols in the 4-hydroxylation pathway was associated with statistically significantly increased risk of breast cancer.
  • This result is consistent with the hypothesis that mutagenic quinones derived from 4-hydroxylation pathway catechols contribute to pathogenesis of postmenopausal breast cancer.
  • Catechols in both the 2- and 4-hydroxylation pathways can be oxidized to form quinones; these reactive electrophiles can then react with DNA to form a variety of adducts
  • Methylation of the catechols prevents their conversion to reactive quinones
  • the most common DNA adducts derived from 4-hydroxylation pathway catechols are depurinating and highly mutagenic (7,40), most of those derived from 2-hydroxylation pathway catechols are stable and can be repaired with little error
  • Nathan Goodyear on 14 Oct 13
     
    Lower 2-OH estrone metabolism associated with lower risk of breast cancer, but 4-OH estrone associated with increased risk of breast cancer.
Nathan Goodyear

NETosis and Neutrophil Extracellular Traps in COVID-19: Immunothrombosis and Beyond - PMC - 0 views

www.ncbi.nlm.nih.gov/...PMC8924116

cancer NETosis SARS-CoV-2 COVID COVID-19 COVID19 platelets

shared by Nathan Goodyear on 18 Apr 23 - No Cached
  • Pneumonia is a typical symptom of COVID-19 infection, while acute respiratory distress syndrome (ARDS) and multiple organ failure are common in severe COVID-19 patients
  • NETs are important for preventing pathogen invasion, their excessive formation can result in a slew of negative consequences, such as autoimmune inflammation and tissue damage
  • SARS-CoV-2 infection has also been linked to increased neutrophil-to-lymphocyte ratios, which is associated with disease severity and clinical prognosis
  • ...40 more annotations...
  • NETosis is a special form of programmed cell death in neutrophils, which is characterized by the extrusion of DNA, histones, and antimicrobial proteins in a web-like structure known as neutrophil extracellular traps (NETs)
    • Nathan Goodyear
      Nathan Goodyear on 23 Apr 23
       
      Definition
  • increased generation of reactive oxygen species (ROS) is a crucial intracellular process that causes NETosis
  • Another indirect route of SARS-CoV-2-induced NET production is platelet activation
  • When NETs are activated in the circulation, they can also induce hypercoagulability and thrombosis
  • In COVID-19, major NET protein cargos of NETs (i.e., NE, MPO, and histones) are significantly elevated.
  • SARS-CoV-2 can also infect host cells through noncanonical receptors such as C-type lectin receptors
  • Immunopathological manifestations, including cytokine storms and impaired adaptive immunity, are the primary drivers behind COVID-19, with neutrophil infiltration being suggested as a significant cause
  • NETosis and NETs are increasingly recognized as causes of vascular injury
  • SARS-CoV-2 and its components (e.g., spike proteins and viral RNA) attach to platelets and increase their activation and aggregation in COVID-19, resulting in vascular injury and thrombosis, both of which are linked to NET formation
    • Nathan Goodyear
      Nathan Goodyear on 23 Apr 23
       
      Connects SARS-CoV-2 to TLR on Platelets to NETosis to metastasis.
  • NET formation may be caused by activated platelets rather than SARS-CoV-2 itself
  • NETosis, leading to aberrant immunity such as cytokine storms, autoimmune disorders, and immunosuppression.
  • early bacterial coinfections were more prevalent in COVID-19 patients than those infected with other viruses
  • NETosis and NETs may also have a role in the development of post COVID-19 syndromes, including lung fibrosis, neurological disorders, tumor growth, and worsening of concomitant disease
    • Nathan Goodyear
      Nathan Goodyear on 23 Apr 23
       
      NETosis-> tumor growth
  • NETs and other by-products of NETosis have been shown to act as direct inflammation amplifiers. Hyperinflammation
  • “cytokine storm”
  • SARS-CoV-2 drives NETosis and NET formation to allow for the release of free DNA and by-products (e.g., elastases and histones). This may trigger surrounding macrophages and endothelial cells to secrete excessive proinflammatory cytokines and chemokines, which, in turn, enhance NET formation and form a positive feedback of cytokine storms in COVID-19
    • Nathan Goodyear
      Nathan Goodyear on 23 Apr 23
       
      Cycle of hyperinflammation
  • NET release enables self-antigen exposure and autoantibody production, thereby increasing the autoinflammatory response
  • patients with COVID-19 who have higher anti-NET antibodies are more likely to be detected with positive autoantibodies [e.g., antinuclear antibodies (ANA) and anti-neutrophil cytoplasmic antibodies (ANCA)]
  • COVID-19 NETs may act as potential inducers for autoimmune responses
  • have weakened adaptive immunity as well as a high level of inflammation
    • Nathan Goodyear
      Nathan Goodyear on 23 Apr 23
       
      Immunomodulation
  • tumor-associated NETosis and NETs promote an immunosuppressive environment in which anti-tumor immunity is compromised
  • NETs have also been shown to enhance macrophage pyroptosis in sepsis
  • facilitating an immunosuppressive microenvironment
  • persistent immunosuppression may result in bacterial co-infection or secondary infection
  • can enhance this process by interacting with neutrophils through toll-like receptor 4 (TLR4), platelet factor 4 (PF4), and extracellular vesicle-dependent processes
  • NET-induced immunosuppression in COVID-19 in the context of co-existing bacterial infection
  • Following initial onset of COVID-19, an estimated 50% or more of COVID-19 survivors may develop multi-organ problems (e.g., pulmonary dysfunction and neurologic impairment) or have worsening concomitant chronic illness
  • NETs in the bronchoalveolar lavage fluid of severe COVID-19 patients cause EMT in lung epithelial cells
  • decreased E-cadherin (an epithelial marker) expression
    • Nathan Goodyear
      Nathan Goodyear on 23 Apr 23
       
      Leads to emt
  • COVID-19 also has a long-term influence on tumor progression
  • Patients with tumors have been shown to be more vulnerable to SARS-CoV-2 infection and subsequent development of severe COVID-19
  • patients who have recovered from COVID-19 may have an increased risk of developing cancer or of cancer progression and metastasis
  • awaken cancer cells
  • NETs have been shown to change the tumor microenvironment
  • enhance tumor progression and metastasis
  • vitamin C has been tested in phase 2 clinical trials aimed at reducing COVID-19-associated mortality by reducing excessive activation of the inflammatory response
  • vitamin C is an antioxidant that significantly attenuates PMA-induced NETosis in healthy neutrophils by scavenging ROS
  • vitamin C may also inhibit NETosis and NET production in COVID-19
  • Metformin
  • Vitamin C
  • Nathan Goodyear on 18 Apr 23
     
    NETosis intimately involved in progressive COVID, long COVID, autoimmunity, and cancer
Nathan Goodyear

Tumor regionalization after surgery: Roles of the tumor microenvironment and neutrophil... - 0 views

www.nature.com/...s12276-022-00784-2

TME NETosis metastasis surgery cancer tumor microenvironment

shared by Nathan Goodyear on 20 Apr 23 - No Cached
  • tumor surgery must be carefully considered because the risk of metastasis could be increased by the surgical procedure.
  • NETosis, which is the process of forming neutrophil extracellular traps (NETs)
  • surgery-induced metastasis
  • ...61 more annotations...
  • surgery per se can promote cancer metastasis through a series of local and systemic events
  • surgery results in a serious wound that disrupts the structural barrier preventing the outspreading of cancer cells, change the properties of the cancer cells and stromal cells remaining in the tumor microenvironment, or impairs the host defense systems against cancers
    • Nathan Goodyear
      Nathan Goodyear on 23 Apr 23
       
      Key point; add to presentation on surgery and metastasis
  • After the primary tumor is surgically removed, the metastases can start to grow vigorously via neoangiogenesis because the circulating inhibitors disappear
  • infection and inflammation during the postoperative period have been reported to increase the risk of cancer recurrence in patients
  • Surgeons have long suspected that surgery, even if it is a necessary step in cancer treatment, facilitates cancer metastasis
  • Surgery-induced cancer metastasis has been well established in animal models
  • tumor cell dissemination, tumor-favoring immune responses, and neoangiogenesis
  • the surgical resection of primary tumors is beneficial is controversial
  • CTCs abruptly increase just after surgery
  • Even externally palpitating tumors for diagnosis could increase the numbers of CTCs in skin cancer and breast cancer
  • excessive glucocorticoids negatively modulate immune functions
  • immune surveillance against tumors is considered to be impaired by surgical stress
  • In addition to glucocorticoids, during stimulation of the HPA axis, the catecholamine hormones epinephrine and norepinephrine are released from the adrenal medulla
  • NK cell suppression may be attributed to increased levels of catecholamines as well as glucocorticoids
  • In mice bearing a primary tumor, it was observed that the removal of the primary tumor facilitated the growth of highly vascularized metastases
  • primary tumors may secrete angiogenic inhibitors as well as angiogenic activators
  • second phase of tumor recurrence and metastasis, which are newly acquired events, rather than just outcomes of incomplete treatment.
    • Nathan Goodyear
      Nathan Goodyear on 23 Apr 23
       
      Another key point
  • double-edged sword
  • HIF-1 in neutrophils plays a critical role in NETosis and bacteria-killing activity
  • neutrophils play various roles in the initiation and progression of cancer
  • NETosis
  • many inflammatory and neoplastic diseases
  • formation of neutrophil extracellular traps (NETs), which are large extracellular complexes composed of chromatin and cytoplasmic/granular proteins1
  • NETosis has been highlighted as an inflammatory event that promotes cancer metastasis
  • Once activated, neutrophils produce intracellular precursors by using DNA, histones, and granular and cytoplasmic proteins and then spread the mature form of NETs out around themselves
  • A series of these events is called NETosis.
  • neutrophil elastase, myeloperoxidase, cathepsin G, proteinase 3, lactoferrin, gelatinase, lysozyme C, calprotectin, neutrophil defensins, and cathelicidins
  • innate immune response against infection
  • Neutrophils are the most abundant type of granulocytes, comprising 40–70% of all white blood cells
  • two types of NEToses, suicidal (or lytic) NETosis and vital NETosis
  • Suicidal NETosis mainly depends on the production of reactive oxygen species (ROS)
  • Since neutrophils die during this process, it is called suicidal NETosis.
  • vital NETosis
  • vital NETosis occurs independently of ROS production
  • Vital NETosis can be induced by Gram-negative bacteria. LPS
  • NETs are present in a variety of cancers, such as lung cancer, colon cancer, ovarian cancer, and leukemia
  • neutrophils actively undergo NETosis in the tumor microenvironment
  • Hypoxia
  • NETosis plays a pivotal role in noninfectious autoimmune diseases,
  • cytokines
  • tumor-derived proteases
  • tumor exosomes
  • NETosis generally actively progresses in the tumor microenvironment.
  • the proliferative cytokines TGFβ and IL-10 and the angiogenic factor VEGF are representative of neutrophil-derived tissue repair proteins.
  • NETosis is a defense system to protect the body from invading pathogens
  • when neutrophils are excessively stimulated, they produce excess NETs, thereby leading to pathological consequences
  • plasma levels of NETosis markers are elevated after major surgeries
  • local invasion, intravasation into the blood or lymphatic vessels, escape from the immune system, anchoring to capillaries in target organs, extravasation into the organs, transformation from dormant cells to proliferating cells, colonization to micrometastases, and growth to macrometastases
  • NETs promote metastasis at multiple steps
  • NETs loosen the ECM and capillary wall to promote the intravasation of cancer cells
  • NETs and platelets wrap CTCs, which protects them from attack by immune cells and shearing force by blood flow
  • NETs promote the local invasion of cancer cells by degrading the extracellular matrix (ECM)
  • neutrophil elastase, matrix metalloproteinase 9, and cathepsin G
  • NETs also promote the intravasation of cancer cells
  • millions of tumor cells are released into the circulation every day,
  • NETs can wrap up CTCs with platelets
  • β1-integrin plays an important role in the interaction between CTCs and NETs
  • NET-platelet-CTC aggregates.
  • After metastasizing to distant tissues, tumor cells are often found to remain dormant for a period of time and unexpectedly regrow late
  • NETs are believed to participate in the reactivation of dormant cancer cells in metastatic regions
  • NET-associated proteases NE and MMP-9 were found to be responsible for the reactivation of dormant cancer cells
  • Nathan Goodyear on 20 Apr 23
     
    Surgery induced metastasis: it is real and steered by NETosis.
Nathan Goodyear

Undetectable circulating tumor DNA (ctDNA) levels correlate with favorable outcome in m... - 0 views

www.ncbi.nlm.nih.gov/...PMC6727487

ctDNA melanoma cancer

shared by Nathan Goodyear on 06 Jul 23 - No Cached
  • Nathan Goodyear on 06 Jul 23
     
    Title tells it all, ctDNA decrease levels portends treatment response.
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