Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 32
Filter
Add more filters










Publication year range
2.
NPJ Breast Cancer ; 8(1): 15, 2022 Jan 27.
Article in English | MEDLINE | ID: mdl-35087024

ABSTRACT

Increased trunk fat is associated with an elevated risk of breast cancer in normal-weight postmenopausal women. The main objective of this study was to determine whether levels of trunk fat are associated with changes in breast gene expression in normal-weight women. Non-tumorous breast tissue was collected from 32 normal BMI women who underwent mastectomy for breast cancer risk reduction or treatment. Body composition was measured by dual-energy x-ray absorptiometry. High levels of trunk fat were associated with a large number of differentially expressed genes and changes in multiple pathways and processes potentially linked to breast cancer pathogenesis. High levels of trunk fat were also associated with an elevated immune score and increased levels of leptin, CCL2, VEGF-C, IL6, and aromatase. Collectively, these results help to explain why high levels of trunk fat are associated with an increased risk of breast cancer in normal BMI women.

4.
Cancer Prev Res (Phila) ; 14(5): 541-550, 2021 05.
Article in English | MEDLINE | ID: mdl-33648942

ABSTRACT

Excess body fat and sedentary behavior are associated with increased breast cancer risk and mortality, including in normal weight women. To investigate underlying mechanisms, we examined whether adiposity and exercise impact the breast microenvironment (e.g., inflammation and aromatase expression) and circulating metabo-inflammatory factors. In a cross-sectional cohort study, breast white adipose tissue (WAT) and blood were collected from 100 women undergoing mastectomy for breast cancer risk reduction or treatment. Self-reported exercise behavior, body composition measured by dual-energy x-ray absorptiometry (DXA), and waist:hip ratio were obtained prior to surgery. Breast WAT inflammation (B-WATi) was assessed by IHC and aromatase expression was assessed by quantitative PCR. Metabolic and inflammatory blood biomarkers that are predictive of breast cancer risk and progression were measured. B-WATi was present in 56 of 100 patients and was associated with older age, elevated BMI, postmenopausal status, decreased exercise, hypertension and dyslipidemia (Ps < 0.001). Total body fat and trunk fat correlated with B-WATi and breast aromatase levels (Ps < 0.001). Circulating C-reactive protein, IL6, insulin, and leptin positively correlated with body fat and breast aromatase levels, while negative correlations were observed for adiponectin and sex hormone binding globulin (P < 0.001). Inverse relationships were observed with exercise (Ps < 0.05). In a subgroup of 39 women with normal BMI, body fat levels positively correlated with B-WATi and aromatase expression (Ps < 0.05). In conclusion, elevated body fat levels and decreased exercise are associated with protumorigenic micro- and host environments in normal, overweight, and obese individuals. These findings support the development of BMI-agnostic lifestyle interventions that target adiposity. PREVENTION RELEVANCE: We report that individuals with high body fat and low exercise levels have breast inflammation, higher breast aromatase expression, and levels of circulating metabo-inflammatory factors that have been associated with increased breast cancer risk. These findings support interventions to lower adiposity, even among normal weight individuals, to prevent tumor growth.


Subject(s)
Adipose Tissue, White/pathology , Adiposity/immunology , Breast Neoplasms/prevention & control , Breast/pathology , Exercise/immunology , Absorptiometry, Photon , Adipose Tissue, White/immunology , Adipose Tissue, White/surgery , Adult , Aged , Aged, 80 and over , Breast/immunology , Breast/surgery , Breast Neoplasms/immunology , Breast Neoplasms/metabolism , Breast Neoplasms/surgery , Cross-Sectional Studies , Exercise/statistics & numerical data , Female , Humans , Mastectomy , Middle Aged , Sedentary Behavior , Self Report/statistics & numerical data , Tumor Microenvironment/immunology
5.
NPJ Breast Cancer ; 7(1): 18, 2021 Mar 01.
Article in English | MEDLINE | ID: mdl-33649363

ABSTRACT

Obesity is associated with an increased risk of breast cancer in post-menopausal women and decreased risk in pre-menopausal women. Conversely, in BRCA1/2 mutation carriers, pre-menopausal obesity is associated with early-onset breast cancer. Here we show that obese, pre-menopausal BRCA1/2 mutation carriers have increased levels of aromatase and inflammation in the breast, as occurs in post-menopausal women. In a prospective cohort study of 141 women with germline BRCA1 (n = 74) or BRCA2 (n = 67) mutations, leptin, and aromatase expression were higher in the breast tissue of obese versus lean individuals (P < 0.05). Obesity was associated with breast white adipose tissue inflammation, which correlated with breast aromatase levels (P < 0.01). Circulating C-reactive protein, interleukin-6, and leptin positively correlated with body mass index and breast aromatase levels, whereas negative correlations were observed for adiponectin and sex hormone-binding globulin (P < 0.05). These findings could help explain the increased risk of early-onset breast cancer in obese BRCA1/2 mutation carriers.

6.
Acad Med ; 95(9S A Snapshot of Medical Student Education in the United States and Canada: Reports From 145 Schools): S371-S374, 2020 Sep.
Article in English | MEDLINE | ID: mdl-33626723
7.
Carcinogenesis ; 40(7): 914-923, 2019 07 20.
Article in English | MEDLINE | ID: mdl-31067318

ABSTRACT

Obesity is associated with an increased incidence of high-grade prostate cancer (PC) and worse prognosis for PC patients. Recently, we showed in men that obesity-related periprostatic white adipose tissue (WAT) inflammation, characterized by macrophages surrounding dead or dying adipocytes forming crown-like structures, was associated with high-grade PC. Possibly, interventions that suppress periprostatic WAT inflammation will improve outcomes for men with PC. Here, we tested the hypothesis that supplemental 17ß-estradiol (E2) could decrease periprostatic WAT inflammation in obese male mice. Mice were fed a high-fat diet to induce periprostatic WAT inflammation before being treated with supplemental E2. E2 supplementation suppressed caloric intake, induced weight loss, decreased periprostatic WAT inflammation and downregulated the expression of genes linked to inflammation including Cd68, Mcp1 and Tnf. Similar to the effects of E2 supplementation, treatment with diethylstilbestrol, a synthetic estrogen, also suppressed caloric intake and reduced periprostatic WAT inflammation. To determine whether the observed effects of supplemental estrogen could be reproduced by caloric restriction (CR) alone, obese mice were put on a 30% CR diet. Like estrogen treatment, CR was effective in reducing body weight, periprostatic WAT inflammation and the expression of pro-inflammatory genes. Transcriptomic analyses of periprostatic fat showed that obesity was associated with enrichment in inflammatory response pathways, which were normalized by both supplemental E2 and CR. Taken together, these findings strengthen the rationale for future efforts to determine whether either CR or supplemental estrogen will decrease periprostatic WAT inflammation and thereby improve outcomes for men with PC.


Subject(s)
Caloric Restriction , Estradiol/administration & dosage , Estrogens/administration & dosage , Inflammation/therapy , Intra-Abdominal Fat/drug effects , Obesity/complications , Adipocytes/immunology , Adipocytes/pathology , Animals , Diet, High-Fat/adverse effects , Disease Models, Animal , Eating/drug effects , Humans , Inflammation/immunology , Inflammation/pathology , Intra-Abdominal Fat/immunology , Intra-Abdominal Fat/pathology , Male , Mice , Obesity/immunology , Obesity/therapy , Prostate/drug effects , Prostate/immunology , Prostate/pathology , Prostatic Neoplasms/immunology , Prostatic Neoplasms/pathology , Prostatic Neoplasms/therapy , Treatment Outcome , Weight Loss/drug effects
8.
Cancer Prev Res (Phila) ; 12(1): 21-30, 2019 01.
Article in English | MEDLINE | ID: mdl-30404870

ABSTRACT

Breast white adipose tissue inflammation (BWATi) is associated with obesity and higher breast cancer risk among non-Hispanic white women. Obesity is prevalent in Hispanic/Latina patients with breast cancer, and the occurrence of BWATi in this population is not well-characterized. The association between BWATi and body mass index (BMI) was evaluated in Hispanic/Latina patients with breast cancer who underwent mastectomy. BWATi was defined as the presence of crown-like structures of the breast (CLS-B), detected by CD68 IHC in nontumor breast tissue. BWATi severity was quantified as number of CLS-B/cm2 Adipocyte diameter was measured using hematoxylin and eosin-stained breast tissue sections. Preoperative BMI (within 1 week prior to mastectomy) was categorized as normal (18.5-<25.0 kg/m2), overweight (25.0-<30.0 kg/m2), class I obesity (30.0-<35.0 kg/m2), and class II-III obesity (35.0 kg/m2 or above). Patient charts were abstracted to record clinicopathologic features and liver function tests <90 days before mastectomy. The study included 91 women (mean age 69 years; range 36-96 years). Prevalence of BWATi increased with BMI (24% in normal weight, 34% in overweight, 57% in class I obesity, and 65% in class II-III obesity; P trend <0.01). Severe BWATi (>0.27 CLS-B/cm2) was associated with higher BMI (P trend = 0.046) and greater adipocyte diameter (P = 0.04). Adjusting for BMI, neoadjuvant chemotherapy, and elevated alanine aminotransferase were associated with severe BWATi, and current smoking was associated with mild BWATi (all P < 0.05). BWATi was associated with higher BMI in Hispanic/Latina patients with breast cancer, consistent with previously described associations in other populations.


Subject(s)
Adipose Tissue, White/physiopathology , Breast Neoplasms/etiology , Hispanic or Latino/statistics & numerical data , Inflammation/etiology , Obesity/complications , Adult , Aged , Aged, 80 and over , Breast Neoplasms/pathology , Female , Follow-Up Studies , Humans , Inflammation/pathology , Middle Aged , Prognosis , Retrospective Studies
9.
JCI Insight ; 3(14)2018 07 26.
Article in English | MEDLINE | ID: mdl-30046001

ABSTRACT

Obesity increases breast cancer mortality by promoting resistance to therapy. Here, we identified regulatory pathways in estrogen receptor-positive (ER-positive) tumors that were shared between patients with obesity and those with resistance to neoadjuvant aromatase inhibition. Among these was fibroblast growth factor receptor 1 (FGFR1), a known mediator of endocrine therapy resistance. In a preclinical model with patient-derived ER-positive tumors, diet-induced obesity promoted a similar gene expression signature and sustained the growth of FGFR1-overexpressing tumors after estrogen deprivation. Tumor FGFR1 phosphorylation was elevated with obesity and predicted a shorter disease-free and disease-specific survival for patients treated with tamoxifen. In both human and mouse mammary adipose tissue, FGF1 ligand expression was associated with metabolic dysfunction, weight gain, and adipocyte hypertrophy, implicating the impaired response to a positive energy balance in growth factor production within the tumor niche. In conjunction with these studies, we describe a potentially novel graft-competent model that can be used with patient-derived tissue to elucidate factors specific to extrinsic (host) and intrinsic (tumor) tissue that are critical for obesity-associated tumor promotion. Taken together, we demonstrate that obesity and excess energy establish a tumor environment with features of endocrine therapy resistance and identify a role for ligand-dependent FGFR1 signaling in obesity-associated breast cancer progression.


Subject(s)
Estrogens/metabolism , Obesity/metabolism , Receptor, Fibroblast Growth Factor, Type 1/metabolism , Receptors, Estrogen/metabolism , Adipose Tissue/metabolism , Adipose Tissue/pathology , Animals , Breast Neoplasms/etiology , Breast Neoplasms/genetics , Diet , Disease Progression , Female , Gene Expression Regulation, Neoplastic , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Humans , Loss of Function Mutation , Mice , Obesity/complications , Obesity/pathology , Receptor, Fibroblast Growth Factor, Type 1/genetics , Signal Transduction , Tamoxifen/therapeutic use , Tumor Microenvironment , Weight Gain
10.
Cancer Prev Res (Phila) ; 11(4): 227-236, 2018 04.
Article in English | MEDLINE | ID: mdl-29222346

ABSTRACT

Obesity is associated with white adipose tissue (WAT) inflammation in the breast, elevated levels of the estrogen biosynthetic enzyme, aromatase, and systemic changes that predispose to breast cancer development. We examined whether WAT inflammation and its associated systemic effects correlate with body fat levels in an Asian population where body mass index (BMI) is not an accurate assessment of obesity and cancer risk. We also investigated whether biologic differences could account for the greater proportion of premenopausal estrogen receptor (ER)-positive breast cancer in Asian versus Western countries. Breast WAT and fasting blood were prospectively collected from Taiwanese women undergoing mastectomy for breast cancer treatment. Body composition was measured in a subgroup using bioelectrical impedance analysis. WAT inflammation was defined by the presence of crown-like structures of the breast, which are composed of dead or dying adipocytes surrounded by macrophages. Findings were compared with U.S. Caucasian women. In the Taiwanese cohort (n = 72), breast WAT inflammation was present in 31 (43%) women and was associated with elevated BMI (P < 0.01) and increased levels of body fat (P < 0.01), C-reactive protein (P = 0.02), triglycerides (P < 0.01), insulin resistance scores (P = 0.04), and lower HDL cholesterol (P < 0.01). ER+ tumors were associated with greater body fat versus other subtypes (P = 0.03). Compared with U.S. Caucasians (n = 267), Taiwanese women had larger breast adipocytes despite lower BMI after adjusting for BMI and menopausal status (P = 0.01). A subclinical inflammatory state associated with increased adiposity and metabolic dysfunction could contribute to breast cancer pathogenesis in Asian women. Cancer Prev Res; 11(4); 227-36. ©2017 AACR.


Subject(s)
Adipose Tissue, White/pathology , Adiposity/immunology , Asian People/statistics & numerical data , Inflammation/complications , Triple Negative Breast Neoplasms/pathology , White People/statistics & numerical data , Adipose Tissue, White/immunology , Adult , Cohort Studies , Cross-Sectional Studies , Female , Follow-Up Studies , Humans , Inflammation/immunology , Middle Aged , Prognosis , Triple Negative Breast Neoplasms/etiology
11.
Cancer Prev Res (Phila) ; 11(4): 215-226, 2018 04.
Article in English | MEDLINE | ID: mdl-29222347

ABSTRACT

Obesity is associated with an increased incidence of high-grade prostate cancer and poor prognosis for prostate cancer patients. Recently, we showed that obesity-related periprostatic white adipose tissue (WAT) inflammation, characterized by crown-like structures (CLS) consisting of dead or dying adipocytes surrounded by macrophages, was associated with high-grade prostate cancer. It is possible, therefore, that agents that suppress periprostatic WAT inflammation will alter the development or progression of prostate cancer. Pioglitazone, a ligand of PPARγ, is used to treat diabetes and possesses anti-inflammatory properties. Here, our main objectives were to determine whether pioglitazone inhibited obesity-related periprostatic WAT inflammation in mice and then to elucidate the underlying mechanism. Treatment with pioglitazone reduced the density of CLS in periprostatic fat and suppressed levels of TNFα, TGFß, and the chemokine monocyte chemoattractant protein-1 (MCP-1). Importantly, the ability of pioglitazone to suppress periprostatic WAT inflammation was abrogated in MCP-1 knockout mice. Pioglitazone caused dose-dependent induction of both adiponectin, an anti-inflammatory adipokine, and its receptor AdipoR2 in cultured 3T3-L1 cells and in periprostatic WAT of obese mice. Pioglitazone blocked TNFα-mediated induction of MCP-1 in 3T3-L1 cells, an effect that was attenuated when either adiponectin or AdipoR2 were silenced. Taken together, pioglitazone-mediated induction of adiponectin suppressed the elevation in MCP-1 levels, thereby attenuating obesity-related periprostatic WAT inflammation. These findings strengthen the rationale for future efforts to determine whether targeting the PPARγ-adiponectin-MCP-1 axis will decrease periprostatic adipose inflammation and thereby reduce the risk of high-grade prostate cancer or improve outcomes for men with prostate cancer. Cancer Prev Res; 11(4); 215-26. ©2017 AACR.


Subject(s)
Adipose Tissue, White/drug effects , Chemokine CCL2/physiology , Hypoglycemic Agents/pharmacology , Inflammation/drug therapy , Pioglitazone/pharmacology , Prostate/drug effects , Adipose Tissue, White/immunology , Adipose Tissue, White/metabolism , Adipose Tissue, White/pathology , Animals , Cells, Cultured , Diet, High-Fat/adverse effects , Inflammation/etiology , Inflammation/metabolism , Inflammation/pathology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Obese , Prostate/immunology , Prostate/metabolism , Prostate/pathology
12.
Cancer Prev Res (Phila) ; 10(4): 235-243, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28270386

ABSTRACT

Obesity is associated with breast white adipose tissue (WAT) inflammation, elevated levels of the estrogen biosynthetic enzyme, aromatase, and systemic changes that have been linked to the pathogenesis of breast cancer. Here, we determined whether metabolic obesity, including changes in breast biology and systemic effects, occurs in a subset of women with normal body mass index (BMI). Breast WAT and fasting blood were collected from 72 women with normal BMI (<25 kg/m2) undergoing mastectomy for breast cancer risk reduction or treatment. WAT inflammation was defined by the presence of crown-like structures of the breast (CLS-B) which are composed of dead or dying adipocytes surrounded by macrophages. Severity of inflammation was measured as CLS-B/cm2 The primary objective was to determine whether breast WAT inflammation is associated with aromatase expression and activity. Secondary objectives included assessment of circulating factors and breast adipocyte size. Breast WAT inflammation was present in 39% of women. Median BMI was 23.0 kg/m2 (range, 18.4-24.9 kg/m2) in women with breast WAT inflammation versus 21.8 kg/m2 (range, 17.3-24.6 kg/m2) in those without inflammation (P = 0.04). Breast WAT inflammation was associated with elevated aromatase expression and activity, which increased with severity of inflammation (P < 0.05). Breast WAT inflammation correlated with larger adipocytes (P = 0.01) and higher circulating levels of C-reactive protein, leptin, insulin, and triglycerides (P ≤ 0.05). A subclinical inflammatory state associated with elevated aromatase in the breast, adipocyte hypertrophy, and systemic metabolic dysfunction occurs in some normal BMI women and may contribute to the pathogenesis of breast cancer. Cancer Prev Res; 10(4); 235-43. ©2017 AACRSee related article by Berger, p. 223-25.


Subject(s)
Adipose Tissue, White/pathology , Aromatase/biosynthesis , Breast Neoplasms/enzymology , Breast Neoplasms/pathology , Inflammation/pathology , Adult , Body Mass Index , Female , Humans , Middle Aged
13.
J Clin Endocrinol Metab ; 102(5): 1692-1701, 2017 05 01.
Article in English | MEDLINE | ID: mdl-28323914

ABSTRACT

Context: Most estrogen-dependent breast cancers occur after menopause, despite low levels of circulating estrogens. Breast expression of the estrogen-biosynthetic enzyme, aromatase, is proposed to drive breast cancer development after menopause. However, the effects of menopause on breast aromatase expression are unknown. Objective: To determine the effect of menopause on breast aromatase expression in relation to body mass index (BMI), white adipose tissue inflammation (WATi), and systemic markers of metabolic dysfunction. Design, Setting, and Participants: Cross-sectional study of 102 premenopausal (age 27 to 56) and 59 postmenopausal (age 45 to 74) women who underwent mastectomy for breast cancer treatment/prevention. Outcome: Breast tissue was assessed for the presence of crown-like structures and the expression and activity of aromatase. Systemic markers examined include interleukin (IL)-6, insulin, glucose, leptin, adiponectin, high-sensitivity C-reactive protein (hsCRP), cholesterol, and triglycerides. Multivariable analysis was performed for aromatase messenger RNA (mRNA) in relation to BMI, WATi, and blood markers. Results: Postmenopausal women had higher BMI and more breast WATi than premenopausal women. Fasting levels of IL-6, glucose, leptin, hsCRP, and homeostatic model assessment 2 insulin resistance score were higher in the postmenopausal group. BMI was positively correlated with aromatase mRNA in both pre- and postmenopausal women. Aromatase levels were higher in breast tissue of postmenopausal women, with levels being higher in inflamed vs noninflamed, independent of BMI. Adipocyte diameter and levels of leptin, hsCRP, adiponectin, and high-density lipoprotein cholesterol were more strongly correlated with aromatase in postmenopausal than premenopausal women. Conclusions: Elevated aromatase in the setting of adipose dysfunction provides a possible mechanism for the higher incidence of hormone-dependent breast cancer in obese women after menopause.


Subject(s)
Adiponectin/metabolism , Adipose Tissue, White/immunology , Aromatase/genetics , Breast/metabolism , C-Reactive Protein/immunology , Interleukin-6/immunology , Leptin/metabolism , Menopause/metabolism , Adult , Aged , Aromatase/metabolism , Blood Glucose/metabolism , Body Mass Index , Breast Neoplasms , Cholesterol/metabolism , Cholesterol, HDL/metabolism , Cholesterol, LDL/metabolism , Female , Gene Expression Regulation, Developmental , Humans , Inflammation , Insulin/metabolism , Insulin Resistance , Middle Aged , Multivariate Analysis , Postmenopause , Premenopause , RNA, Messenger/metabolism , Triglycerides/metabolism
14.
Diabetes ; 65(6): 1577-89, 2016 06.
Article in English | MEDLINE | ID: mdl-27207531

ABSTRACT

Insulin controls glucose uptake into adipose and muscle cells by regulating the amount of GLUT4 in the plasma membrane. The effect of insulin is to promote the translocation of intracellular GLUT4 to the plasma membrane. The small Rab GTPase, Rab10, is required for insulin-stimulated GLUT4 translocation in cultured 3T3-L1 adipocytes. Here we demonstrate that both insulin-stimulated glucose uptake and GLUT4 translocation to the plasma membrane are reduced by about half in adipocytes from adipose-specific Rab10 knockout (KO) mice. These data demonstrate that the full effect of insulin on adipose glucose uptake is the integrated effect of Rab10-dependent and Rab10-independent pathways, establishing a divergence in insulin signal transduction to the regulation of GLUT4 trafficking. In adipose-specific Rab10 KO female mice, the partial inhibition of stimulated glucose uptake in adipocytes induces insulin resistance independent of diet challenge. During euglycemic-hyperinsulinemic clamp, there is no suppression of hepatic glucose production despite normal insulin suppression of plasma free fatty acids. The impact of incomplete disruption of stimulated adipocyte GLUT4 translocation on whole-body glucose homeostasis is driven by a near complete failure of insulin to suppress hepatic glucose production rather than a significant inhibition in muscle glucose uptake. These data underscore the physiological significance of the precise control of insulin-regulated trafficking in adipocytes.


Subject(s)
Adipocytes/metabolism , Glucose Transporter Type 4/metabolism , Insulin Resistance , Insulin/metabolism , Liver/metabolism , rab GTP-Binding Proteins/deficiency , 3T3-L1 Cells , Animals , Cell Membrane/metabolism , Female , Glucose/biosynthesis , Mice , Mice, Inbred C57BL , Mice, Knockout , Muscle, Skeletal/metabolism , Protein Transport , Signal Transduction
15.
J Lipid Res ; 57(6): 980-92, 2016 06.
Article in English | MEDLINE | ID: mdl-27044658

ABSTRACT

Many types of apoptotic cells are phagocytosed and digested by macrophages. Adipocytes can be hundreds of times larger than macrophages, so they are too large to be digested by conventional phagocytic processes. The nature of the interaction between macrophages and apoptotic adipocytes has not been studied in detail. We describe a cellular process, termed exophagy, that is important for macrophage clearance of dead adipocytes and adipose tissue homeostasis. Using mouse models of obesity, human tissue, and a cell culture model, we show that macrophages form hydrolytic extracellular compartments at points of contact with dead adipocytes using local actin polymerization. These compartments are acidic and contain lysosomal enzymes delivered by exocytosis. Uptake and complete degradation of adipocyte fragments, which are released by extracellular hydrolysis, leads to macrophage foam cell formation. Exophagy-mediated foam cell formation is a highly efficient means by which macrophages internalize large amounts of lipid, which may ultimately overwhelm the metabolic capacity of the macrophage. This process provides a mechanism for degradation of objects, such as dead adipocytes, that are too large to be phagocytosed by macrophages.


Subject(s)
Adipocytes/physiology , Exocytosis/physiology , Macrophages/physiology , Obesity/physiopathology , Phagocytosis/physiology , Adipose Tissue/metabolism , Adipose Tissue/physiology , Animals , Foam Cells/pathology , Foam Cells/physiology , Humans , Lysosomes/physiology , Macrophages/metabolism , Mice , Obesity/metabolism
16.
Cancer Prev Res (Phila) ; 8(8): 751-9, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26038116

ABSTRACT

Obesity is a risk factor for the development of hormone receptor (HR)-positive breast cancer in postmenopausal women. Obesity causes subclinical inflammation in white adipose tissue (WAT), characterized by macrophages surrounding dead or dying adipocytes forming crown-like structures (CLS). Estrogen synthesis is catalyzed by aromatase. Previously, we demonstrated CLS and elevated levels of proinflammatory mediators and aromatase in the mammary glands of obese mice and breast tissue of obese women. Here, we tested the hypothesis that supplemental estrogen could prevent or reverse WAT inflammation (WATi) and related molecular changes in the mammary gland. C57BL/6J mice were ovariectomized (OVX) to simulate the postmenopausal state. Supplementation with 17ß-estradiol (E2) protected against high fat diet (HFD)-induced weight gain and mammary glands WATi. Expression of proinflammatory mediators (Cox-2, TNFα, IL1ß) and aromatase were also reduced in the mammary glands of mice that received supplemental E2. Next, to determine whether E2 supplementation can reverse WATi, obese OVX mice were treated with E2 or placebo and then continued on HFD. E2 supplementation induced weight loss, reversed mammary gland inflammation, and downregulated expression of proinflammatory mediators and aromatase. Finally, we determined whether the protective effects of E2 were mediated by estrogen receptor-α (ERα). Knocking out ERα in ovary intact mice fed a HFD led to weight gain, WATi and elevated levels of proinflammatory mediators and aromatase mimicking the effects of OVX. Taken together, our findings indicate that estrogen via ERα protects against weight gain, WATi and associated increases in proinflammatory mediators and aromatase in the mammary gland.


Subject(s)
Estrogens/therapeutic use , Mammary Glands, Animal/drug effects , Mastitis/prevention & control , Obesity/complications , Animals , Diet, High-Fat/adverse effects , Female , Inflammation Mediators/metabolism , Mammary Glands, Animal/pathology , Mastitis/etiology , Mice , Mice, Inbred C57BL , Obesity/physiopathology , Ovariectomy , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Weight Gain/drug effects
17.
Cancer Prev Res (Phila) ; 8(5): 349-58, 2015 May.
Article in English | MEDLINE | ID: mdl-25720743

ABSTRACT

Chronic inflammation is recognized as a risk factor for the development of several malignancies. Local white adipose tissue (WAT) inflammation, defined by the presence of dead or dying adipocytes encircled by macrophages that form crown-like structures (CLS), occurs in the breasts (CLS-B) of most overweight and obese women. Previously, we showed that the presence of CLS-B is associated with elevated tissue levels of proinflammatory mediators and aromatase, the rate-limiting enzyme for estrogen biosynthesis. The associated increased levels of aromatase in the breast provide a plausible mechanistic link between WAT inflammation and estrogen-dependent breast cancers. Thus, breast WAT inflammation could be relevant for explaining the high incidence of estrogen-dependent tumors with aging despite diminished circulating estrogen levels after menopause. To explore this possibility, we determined whether menopause in addition to body mass index (BMI) is associated with breast WAT inflammation among 237 prospectively enrolled women. The presence of CLS-B and its severity (CLS-B/cm(2)) as indicators of WAT inflammation correlated with menopausal status (P = 0.008 and P < 0.001) and BMI (P < 0.001 for both). In multivariable analyses adjusted for BMI, the postmenopausal state was independently associated with the presence (P = 0.03) and severity of breast WAT inflammation (P = 0.01). Mean adipocyte size increased in association with CLS-B (P < 0.001). Our findings demonstrate that breast WAT inflammation, which is associated with elevated aromatase levels, is increased in association with the postmenopausal state independent of BMI. Breast WAT inflammation, a process that can potentially be targeted, may help to explain the high incidence of estrogen-dependent tumors in postmenopausal women.


Subject(s)
Mastitis/epidemiology , Menopause/physiology , Panniculitis/epidemiology , Adipocytes/pathology , Adipose Tissue/pathology , Adult , Aged , Aged, 80 and over , Body Mass Index , Breast/pathology , Female , Humans , Mastitis/complications , Middle Aged , Panniculitis/complications , Risk Factors , Young Adult
18.
J Immunol ; 192(1): 349-57, 2014 Jan 01.
Article in English | MEDLINE | ID: mdl-24285838

ABSTRACT

The mechanisms by which IL-6 contributes to the pathogenesis of chronic inflammatory diseases and cancer are not fully understood. We previously reported that cyclooxygenase-2 (Cox-2)-dependent PGE2 synthesis regulates macrophage matrix metalloproteinase (MMP)-9 expression, an endopeptidase that participates in diverse pathologic processes. In these studies, we determined whether IL-6 regulates the Cox-2→PGE2→MMP-9 pathway in murine macrophages. IL-6 coinduced Cox-2 and microsomal PGE synthase-1, and inhibited the expression of 15-hydroxyprostaglandin dehydrogenase, leading to increased levels of PGE2. In addition, IL-6 induced MMP-9 expression, suggesting that the observed proteinase expression was regulated by the synthesis of PGE2. However, inhibition of PGE2 synthesis partially suppressed IL-6-mediated induction of MMP-9. In the canonical model of IL-6-induced signaling, JAK activation triggers STAT and MAPK(erk1/2)-signaling pathways. Therefore, the ability of structurally diverse JAK inhibitors to block IL-6-induced MMP-9 expression was examined. Inhibition of JAK blocked IL-6-induced phosphorylation of STAT3, but failed to block the phosphorylation of MAPK(erk1/2), and unexpectedly enhanced MMP-9 expression. In contrast, MEK-1 inhibition blocked IL-6-induced phosphorylation of MAPK(erk1/2) and MMP-9 expression without affecting the phosphorylation of STAT3. Thus, IL-6-induced MMP-9 expression is dependent on the activation of MAPK(erk1/2) and is restrained by a JAK-dependent gene product. Using pharmacologic and genetic approaches, we identified JAK-dependent induction of IL-10 as a potent feedback mechanism controlling IL-6-induced MMP-9 expression. Together, these data reveal that IL-6 induces MMP-9 expression in macrophages via Cox-2-dependent and -independent mechanisms, and identifies a potential mechanism linking IL-6 to the pathogenesis of chronic inflammatory diseases and cancer.


Subject(s)
Gene Expression Regulation/drug effects , Interleukin-10/genetics , Interleukin-6/pharmacology , Janus Kinases/metabolism , Macrophages/drug effects , Macrophages/metabolism , Matrix Metalloproteinase 9/metabolism , Animals , Cell Line , Cyclooxygenase 2/genetics , Cyclooxygenase 2/metabolism , Dinoprostone/biosynthesis , Extracellular Signal-Regulated MAP Kinases/metabolism , Hydroxyprostaglandin Dehydrogenases/genetics , Hydroxyprostaglandin Dehydrogenases/metabolism , Interleukin-10/metabolism , Intramolecular Oxidoreductases/genetics , Intramolecular Oxidoreductases/metabolism , Janus Kinases/antagonists & inhibitors , Mice , Models, Biological , Piperidines/pharmacology , Prostaglandin-E Synthases , Pyrimidines/pharmacology , Pyrroles/pharmacology
19.
Cancer Prev Res (Phila) ; 6(4): 282-9, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23430756

ABSTRACT

Obesity is a risk factor for the development of hormone receptor-positive breast cancer in postmenopausal women. Estrogen synthesis is catalyzed by aromatase. Recently, we identified an obesity→inflammation→aromatase axis in mouse models and women. In mouse models of obesity, inflammatory foci characterized by crown-like structures (CLS) consisting of dead adipocytes encircled by macrophages were found in the mammary gland. CLS of the breast were found in most overweight and obese women. CLS were associated with adipocyte hypertrophy, activation of NF-κB, elevated levels of proinflammatory mediators and aromatase, and increased expression of the progesterone receptor (PR). Collectively, these findings provide a plausible explanation for the link between obesity, chronic inflammation, and postmenopausal breast cancer. Here, we investigated whether caloric restriction (CR) reversed the inflammatory state and related molecular changes in the mammary gland of obese mice. Obese ovariectomized C57BL/6J mice were subjected to 30% CR for 7 or 14 weeks. Findings in CR mice were compared with the results in mice fed a high-fat diet ad libitum or with control mice fed a low-fat diet. CR was associated with more than a 75% decrease in mammary CLS/cm(2). Reduced histologic inflammation following CR was associated with decreased adipocyte diameter and monocyte chemoattractant protein-1 (MCP-1) levels, reduced NF-κB binding activity, and normalization of levels of proinflammatory mediators, aromatase, and PR. In summary, obesity-related inflammation of the mammary gland and elevated aromatase and PR levels were reversed with CR. Our results provide a rationale for determining whether weight loss can reverse breast inflammation associated with obesity in women.


Subject(s)
Caloric Restriction , Mastitis/diet therapy , Mastitis/etiology , Obesity/complications , Obesity/diet therapy , Animals , Aromatase/genetics , Aromatase/metabolism , Disease Models, Animal , Female , Inflammation Mediators/metabolism , Mammary Glands, Animal/metabolism , Mammary Glands, Animal/pathology , Mastitis/metabolism , Mastitis/pathology , Mice , Mice, Inbred C57BL , Obesity/genetics , Obesity/metabolism , Receptors, Progesterone/genetics , Receptors, Progesterone/metabolism , Weight Gain/immunology
20.
J Biomed Biotechnol ; 2012: 406273, 2012.
Article in English | MEDLINE | ID: mdl-23193360

ABSTRACT

Since its discovery as a src kinase substrate more than three decades ago, appreciation for the physiologic functions of annexin A2 and its associated proteins has increased dramatically. With its binding partner S100A10 (p11), A2 forms a cell surface complex that regulates generation of the primary fibrinolytic protease, plasmin, and is dynamically regulated in settings of hemostasis and thrombosis. In addition, the complex is transcriptionally upregulated in hypoxia and promotes pathologic neoangiogenesis in the tissues such as the retina. Dysregulation of both A2 and p11 has been reported in examples of rodent and human cancer. Intracellularly, A2 plays a critical role in endosomal repair in postarthroplastic osteolysis, and intracellular p11 regulates serotonin receptor activity in psychiatric mood disorders. In human studies, the A2 system contributes to the coagulopathy of acute promyelocytic leukemia, and is a target of high-titer autoantibodies in patients with antiphospholipid syndrome, cerebral thrombosis, and possibly preeclampsia. Polymorphisms in the human ANXA2 gene have been associated with stroke and avascular osteonecrosis of bone, two severe complications of sickle cell disease. Together, these new findings suggest that manipulation of the annexin A2/S100A10 system may offer promising new avenues for treatment of a spectrum of human disorders.


Subject(s)
Annexin A2/metabolism , Disease , Health , S100 Proteins/metabolism , Animals , Disease Models, Animal , Humans
SELECTION OF CITATIONS
SEARCH DETAIL
...