Abstract P3-03-12: Obesity promotes the activation of genes and pathways in tumor associated breast fat

Tumor-associated adipocytes play an active role in breast tumor progression. Moreover, obesity has been established as a risk factor in cancer-related mortality. The altered expression of genes and signaling pathways in breast adipose as a result of obesity may create a more favorable microenvironment for tumor progression. To this end, we analyzed transcriptome profiles of human adipose tissue from lean and obese women with invasive breast cancer using RNA sequencing (n=10/group). Within individuals, adipose tissue was sampled proximal and distal (2 cm) to the breast tumor. A heat map of normalized expression values was generated with unsupervised clustering for the most informative genes. A cluster heat map was obtained by the analysis of the express of 35 DEGs with the most significant differences (adjusted p-value P< 0.01 and fold change > 2) recorded. Starting with a list of genes marked as significant in the analysis of lean vs obese, we queried the STRING database. Using ClusterMaker2 and MCL clustering, we performed enrichment analysis and found KEGG pathway hsa05224 breast cancer was enriched with an FDR of 2.7e-40. Using KEGGParser, we over-layed fold changes from lean vs obese data. In examining obese women, there were 16 Hallmark pathways that were statistically significant (adjusted p-value P< 0.10); whereas a subset of these (11 pathways) were significant in lean women. Pathways that were significant in both lean and obese individuals were pathways that regulate EMT, adipogenesis and TGF-β signaling. EMT transcription factors and TGF-β signaling are known to regulate cancer adipogenesis. The results underscore the link between obesity and altered gene expression in mammary fat associated with breast cancer. (Supported by NIH P20GM103434 and NIGMS U54GM104942)

Citation Format: Niel Infante, James Coad, Don Primerano, James Denvir, Linda Vona-Davis. Obesity promotes the activation of genes and pathways in tumor associated breast fat [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-03-12.

Abstract 4241: Molecular profile of tumor-associated adipose in obese women with breast cancer

Breast tumors have a direct physical and vascular interface with white adipose tissue, making them ideal model systems to study the adipose-tumor microenvironment, especially within the context of obesity. As a first initiative to understanding how adipose tissue contributes to breast tumor etiology, we explored cancer-associated adipose tissue in patients with invasive breast cancer. We hypothesized that obesity leads to greater alterations in cancer-associated adipose tissue by expressing genes involved in cellular growth, angiogenesis, and invasion, thus providing support for breast cancer progression. We also proposed that adipocytes adjacent to tumors express a genotype unique to obese breast cancers. Adipose tissue samples (n=10) were obtained from obese and lean women with breast cancer. Within individuals, tissue was sampled proximal and distal (2 cm) to the tumor. Using next-generation whole transcriptome sequencing, we examined genes from cancer-associated adipose tissue in both groups. A heat map of normalized expression values was generated with unsupervised clustering and the fifty most informative genes. Samples from obese individuals with breast cancer tended to cluster together. There were significant gene differences between adipose collected proximal versus distal from the tumor in obese but not in lean women, such as genes associated with myosin heavy chains MYH1, 4, 8, and 11 (adj. p < 0.05). In examining obese women, there were 16 Hallmark pathways that were statistically significant (adj. p < 0.10); whereas a subset of these (11 pathways) were significant in lean women. Of interest, pathways that were significant in both were pathways that regulate EMT, adipogenesis and TGF beta signaling. The molecular signature of cancer-associated adipocytes is different between lean and obese patients. (Supported by NIH P20GM103434 and NIGMS U54GM104942)

Citation Format: Niel Infante, James Coad, Donald Primerano, James Denvir, Linda Vona-Davis. Molecular profile of tumor-associated adipose in obese women with breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4241.

Abstract 4492: Aggressive breast cancer cells reduce CCL5 and Nodal expression in response to a human adipose-derived stromal cell microenvironment

Clinical studies indicate that obesity is correlated with poor outcomes in breast cancer patients. Obese individuals have a high proportion of adipose tissue, which is abundant in stem and progenitor cells. Human adipose-derived stromal cells (hADSCs) secrete several cytokines including CCL5, an inflammatory chemokine shown to increase tumor metastatic ability in vitro. We previously identified that CCL5 is secreted into the microenvironment when hADSCs are co-cultured with breast tumor cells. When the clinical relevance of CCL5 was assessed using cBioPortal, an open-source genomics database, we found that CCL5 mRNA overexpression was correlated with increased overall survival in breast cancer patients, which counters what we and others have observed in vitro. In this study, we compared the expression of CCL5 and Nodal, a potent embryonic morphogen re-expressed by aggressive cancer cells, in either hADSC or MDA-MB-231 breast cancer cells in response to three-dimensional collagen matrices conditioned by hADSCs or breast cancer cells. After preconditioning a three-dimensional collagen matrix with either hADSCs or MDA-MB-231 cells (and following removal of the cells), the denuded three-dimensional matrices were reseeded with the opposite cell type. We found that the expression of both CCL5 and Nodal was significantly reduced in the breast cancer cells plated on the hADSC-preconditioned matrix. However, hADSCs did not express Nodal or alter CCL5 protein expression when grown on a MDA-MB-231-preconditioned matrix. MDA-MB-231 cells plated onto a hADSC-preconditioned matrix appeared more mesenchymal and stem-like, while the adipose stem cells placed into a tumor-preconditioned matrix were induced into a more aggressive cancer cell phenotype by engaging in vasculogenic mimicry. Furthermore, we found there was no change in cell proliferation of any cells grown under these different conditions. These observations suggest a relationship between hADSCs and the breast tumor microenvironment where human adipose-derived stem cells appear to inhibit the expression of CCL5 and Nodal by the aggressive tumor cells without altering tumor cell proliferation.

Citation Format: Daniel Berrebi, Abhishek Yadav, Eric Lundstrom, Nicole Werwie, Dominic Muttillo, Richard E. Seftor, Elisabeth A. Seftor, Linda Vona-Davis. Aggressive breast cancer cells reduce CCL5 and Nodal expression in response to a human adipose-derived stromal cell microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4492.

Abstract P5-03-10: IL-6 and CCL5 secretion by adipose-derived stem cells and the breast tumor microenvironment

Introduction: Obesity is a key factor in promoting aggressive breast cancers in women. In previous studies, we found increased production of IL-6 and CCL5, common pro-inflammatory cytokines, in co-cultures of adipose stem cells and triple negative breast tumor cells. When we probed The Cancer Genome Atlas (TCGA) for triple negative breast cancer, we discovered that CCL5 overexpression was associated with improved survival. This finding contradicts the majority of in vitro studies regarding the role of CCL5 in the breast tumor microenvironment; the literature suggests that CCL5 promotes tumor metastatic ability. Furthermore, TCGA data did not indicate a significant correlation between IL-6 production and survival outcomes. It remains unclear whether CCL5 and IL-6 are produced by adipose stromal cells or cancer cells within the tumor microenvironment. We predict that the primary source of CCL5 and IL-6 is from adipose stromal cells. However, the production of these cytokines may be altered when exposed to tumor-secreted factors. Methods: Adipose-derived stem cells (ASC) and preadipocytes differentiated from ASCs (Pread(A)) were treated with the conditioned media of triple negative breast tumor cells (MDA-MB-231) and luminal A breast tumor cells (MCF-7). In addition, MDA-MB-231 and MCF-7 cells were treated with the conditioned media of each adipose stromal cell type. After 72 hours of treatment, the media harvested from each cell type was analyzed for secreted IL-6 and CCL5 proteins. Results: IL-6 and CCL5 levels in the conditioned media of ASCs treated with MDA-MB-231 or MCF-7 cells were significantly lower (p<0.05) when compared to the media of ASCs alone. The reverse occurred when tumor cells were provided conditioned media from adipose progenitor cells. When both breast tumor cell lines were exposed to conditioned media from ASCs and Pread(A), the secretion of IL-6 and CCL5 increased significantly (p<0.05). The conditioned media of Pread(A) cells treated with breast tumor cells were lower than untreated cells, however, this decrease in cytokine production was not significant. Conclusions: This study suggests that IL-6 and CCL5 secretion by adipocytes is modified by the presence of breast tumor cells. The significant decrease in IL-6 and CCL5 secretion from both adipose-derived stem cells and preadipocytes in the presence of tumor may suggest an attempt by the tumor to inhibit an inflammatory response by adipose stromal cells while increasing its own IL-6 and CCL5 production. Although the human genome data indicates that CCL5 and IL-6 provide a survival benefit in vivo, laboratory in vitro studies thus far have failed to mimic the observed clinical responses. Further studies will investigate the clinical relevance of CCL5 and IL-6 receptors in breast cancer. (Supported by NIH P20GM103434 and NIGMS U54GM104942)

Citation Format: Vona-Davis L, Lundstrom E, Berrebi D, Werwie N, Yadav A. IL-6 and CCL5 secretion by adipose-derived stem cells and the breast tumor microenvironment [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-03-10.

Hyperspectral Imaging and K-Means Classification for Histologic Evaluation of Ductal Carcinoma In Situ

Hyperspectral imaging (HSI) is a non-invasive optical imaging modality that shows the potential to aid pathologists in breast cancer diagnoses cases. In this study, breast cancer tissues from different patients were imaged by a hyperspectral system to detect spectral differences between normal and breast cancer tissues. Tissue samples mounted on slides were identified from 10 different patients. Samples from each patient included both normal and ductal carcinoma tissue, both stained with hematoxylin and eosin stain and unstained. Slides were imaged using a snapshot HSI system, and the spectral reflectance differences were evaluated. Analysis of the spectral reflectance values indicated that wavelengths near 550 nm showed the best differentiation between tissue types. This information was used to train image processing algorithms using supervised and unsupervised data. The K-means method was applied to the hyperspectral data cubes, and successfully detected spectral tissue differences with sensitivity of 85.45%, and specificity of 94.64% with true negative rate of 95.8%, and false positive rate of 4.2%. These results were verified by ground-truth marking of the tissue samples by a pathologist. In the hyperspectral image analysis, the image processing algorithm, K-means, shows the greatest potential for building a semi-automated system that could identify and sort between normal and ductal carcinoma in situ tissues.

Abstract B16: The detection of ductal carcinoma using noninvasive hyperspectral imaging

Introduction: Hyperspectral imaging (HSI) technology is an optical medical imaging modality that has great potential for noninvasive tissue analysis in breast cancer. This imaging method may be able to enhance the detection of cancer tissue and lead to advances in the optical diagnosis of patients. Objective: The goal of this study was to use high resolution hyperspectral imaging microscopy to differentiate marked biopsies of normal and breast cancer tissues. Methods: For our hyperspectral imaging platform, we obtained stained (n=10) and unstained (n=10) pathology slides from ductal carcinomas of the breast and compared them. To capture the HSI, we used a hyperspectral camera that generates a spectral cube containing the spectra of each pixel between 460 to 640 nm and normalized the data to a gray scale to maximize data stability. The spectral signatures were graphed using MATLAB software. Results: The system was able to detect a clear spectral difference between cancer and normal tissues in hematoxylin and eosin stained slides. The spectrum of cancer tissue had a relatively lower intensity than that of normal tissue in the wavelength range between 480 and 610 nm. Conclusions: Our preliminary study showed a clear hyperspectral snapshot differentiating normal breast tissue from ductal carcinoma. Further HSI and quantitative analysis will demonstrate the feasibility of using this new imaging technique in breast cancer.

Citation Format: Yasser Khouj, Jeremy Dawson, James Coad, Linda Vona-Davis. The detection of ductal carcinoma using noninvasive hyperspectral imaging. [abstract]. In: Proceedings of the AACR Special Conference on Engineering and Physical Sciences in Oncology; 2016 Jun 25-28; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2017;77(2 Suppl):Abstract nr B16.

Loss of Adipocyte VEGF Impairs Endurance Exercise Capacity in Mice

PURPOSE

Reducing vascular endothelial growth factor (VEGF) in adipose tissue alters adipose vascularity and metabolic homeostasis. We hypothesized that this would also affect metabolic responses during exercise-induced stress and that adipocyte-specific VEGF-deficient (adipoVEGF-/-) mice would have impaired endurance capacity.

METHODS

Endurance exercise capacity in adipoVEGF-/- (n = 10) and littermate control (n = 11) mice was evaluated every 4 wk between 6 and 24 wk of age using a submaximal endurance run to exhaustion at 20 m·min(-1) at 10° incline. Maximal running speed, using incremental increases in speed at 30-s intervals, was tested at 25 and 37 wk of age.

RESULTS

White and brown adipose tissue capillarity were reduced by 40% in adipoVEGF-/-, and no difference in skeletal muscle capillarity was observed. Endurance run time to exhaustion was 30% lower in adipoVEGF-/- compared with that in controls at all time points (P < 0.001), but no difference in maximal running speed was observed between the groups. After exercise (1 h at 50% maximum running speed), adipoVEGF-/- mice displayed lower circulating insulin (P < 0.001), lower glycerol (P < 0.05), and tendency for lower blood glucose (P = 0.06) compared with controls. There was no evidence of altered oxidative damage or changes in carnitine palmitoyltransferase-1β expression in skeletal muscle of adipoVEGF-/- mice.

CONCLUSIONS

These data suggest that VEGF-mediated deficits in adipose tissue blunt the availability of lipid substrates during endurance exercise, which likely reduced endurance performance. Surprisingly, we also found an unchanged basal blood glucose despite lower circulating insulin in adipoVEGF-/- mice, suggesting that loss of adipocyte VEGF can blunt insulin release and/or increase basal insulin sensitivity.

Essential Components of Cancer Education

Modern cancer therapy/care involves the integration of basic, clinical, and population-based research professionals using state-of-the-art science to achieve the best possible patient outcomes. A well-integrated team of basic, clinical, and population science professionals and educators working with a fully engaged group of creative junior investigators and trainees provides a structure to achieve these common goals. To this end, the structure provided by cancer-focused educational programs can create the integrated culture of academic medicine needed to reduce the burden of cancer on society. This summary outlines fundamental principles and potential best practice strategies for the development of integrated educational programs directed at achieving a work force of professionals that broadly appreciate the principals of academic medicine spanning the breadth of knowledge necessary to advance the goal of improving the current practice of cancer care medicine.

The Interactions of Obesity, Inflammation and Insulin Resistance in Breast Cancer

Obese postmenopausal women have an increased breast cancer risk, the principal mechanism for which is elevated estrogen production by adipose tissue; also, regardless of menstrual status and tumor estrogen dependence, obesity is associated with biologically aggressive breast cancers. Type 2 diabetes has a complex relationship with breast cancer risk and outcome; coexisting obesity may be a major factor, but insulin itself induces adipose aromatase activity and estrogen production and also directly stimulates breast cancer cell growth and invasion. Adipose tissue inflammation occurs frequently in obesity and type 2 diabetes, and proinflammatory cytokines and prostaglandin E2 produced by cyclooxygenase-2 in the associated infiltrating macrophages also induce elevated aromatase expression. In animal models, the same proinflammatory mediators, and the chemokine monocyte chemoattractant protein-1, also stimulate tumor cell proliferation and invasion directly and promote tumor-related angiogenesis. We postulate that chronic adipose tissue inflammation, rather than body mass index-defined obesity per se, is associated with an increased risk of type 2 diabetes and postmenopausal estrogen-dependent breast cancer. Also, notably before the menopause, obesity and type 2 diabetes, or perhaps the associated inflammation, promote estrogen-independent, notably triple-negative, breast cancer development, invasion and metastasis by mechanisms that may involve macrophage-secreted cytokines, adipokines and insulin.

Exercise and dietary advice intervention for survivors of triple-negative breast cancer: effects on body fat, physical function, quality of life, and adipokine profile

PURPOSE

Regular exercise and healthy eating are routinely recommended for breast cancer survivors, and past studies show benefits in quality of life and decreased inflammation. However, this has not been tested specifically in triple-negative breast cancer survivors. Increasing physical activity and losing body fat are thought to positively affect inflammatory biomarkers that have been associated with breast cancer. Therefore, the primary purpose of this study was to determine if participation in an exercise and dietary counseling program can improve body fat, physical function, and quality of life in survivors of this aggressive breast cancer. Secondarily, we sought to determine if participation in the program had beneficial effects on obesity-related markers of the adipokine profile.

METHODS

Sixty-six survivors of triple-negative breast cancer with BMI >25 were invited to participate. Twenty-eight enrolled and 23 completed the randomized, controlled trial (13 intervention, 10 control). Moderate-intensity aerobic exercise (150 min per week, for 12 weeks) and diet counseling were compared to usual care, education only. The primary outcome of interest was weight loss (body mass, BMI, % fat), and secondary outcomes included physical function (exercise capacity), quality of life (Function After Cancer Therapy-Breast (FACT-B)), cytokines (C-reactive protein (CRP), TNF-α, IL-6), and adipokine profile (leptin, adiponectin, insulin).

RESULTS

Participants in the program lost more body fat (2.4 % loss vs. 0.4 % gain, p < 0.05) than the control group. The intervention group also improved quality of life (FACT-B total score +14 pts) and decreased sedentary time but did not improve peak exercise capacity. The intervention had no effect on serum cytokines and adipokines after 12 weeks in the program. However, serum leptin and adiponectin and their ratio were significantly correlated with BMI in the intervention group (p < 0.05).

CONCLUSIONS

Exercise and dietary counseling led to loss of body fat and improved quality of life in survivors of triple-negative breast cancer. BMI was associated with favorable changes in leptin and adiponectin which may reflect a change in adiposity with intervention. Exercise and healthy eating may be equally effective in this high-risk population as in other breast cancer survivors and should be encouraged as a part of a cancer survivorship program.

High-Fat, High-Calorie Diet Enhances Mammary Carcinogenesis and Local Inflammation in MMTV-PyMT Mouse Model of Breast Cancer

Epidemiological studies provide strong evidence that obesity and the associated adipose tissue inflammation are risk factors for breast cancer; however, the molecular mechanisms are poorly understood. We evaluated the effect of a high-fat/high-calorie diet on mammary carcinogenesis in the immunocompetent MMTV-PyMT murine model. Four-week old female mice (20/group) were randomized to receive either a high-fat (HF; 60% kcal as fat) or a low-fat (LF; 16% kcal) diet for eight weeks. Body weights were determined, and tumor volumes measured by ultrasound, each week. At necropsy, the tumors and abdominal visceral fat were weighed and plasma collected. The primary mammary tumors, adjacent mammary fat, and lungs were preserved for histological and immunohistochemical examination and quantification of infiltrating macrophages, crown-like structure (CLS) formation, and microvessel density. The body weight gains, visceral fat weights, the primary mammary tumor growth rates and terminal weights, were all significantly greater in the HF-fed mice. Adipose tissue inflammation in the HF group was indicated by hepatic steatosis, pronounced macrophage infiltration and CLS formation, and elevations in plasma monocyte chemoattractant protein-1 (MCP-1), leptin and proinflammatory cytokine concentrations. HF intake was also associated with higher tumor-associated microvascular density and the proangiogenic factor MCP-1. This study provides preclinical evidence in a spontaneous model of breast cancer that mammary adipose tissue inflammation induced by diet, enhances the recruitment of macrophages and increases tumor vascular density suggesting a role for obesity in creating a microenvironment favorable for angiogenesis in the progression of breast cancer.

Abstract P1-09-12: Effect of a 12-week supervised physical activity and healthy eating program on body weight, functional capacity and serum biomarkers in survivors of triple-negative breast cancer: A randomized, controlled trial

Regular physical activity and healthy body composition are important predictors of good outcomes for breast cancer survivors, especially in overweight/obese individuals. However, individualized exercise and healthy eating programs have not focused on lifestyle changes and outcomes among women recovering from triple-negative breast cancer. Our purpose was to examine the associations between baseline levels of inflammatory cytokines and obesity-related adipokines after weight loss, diet and physical activity intervention in survivors of triple-negative breast cancer. We enrolled overweight/obese survivors (average time since diagnosis, 4 years) and randomly assigned them to a 12-week supervised exercise and low-fat diet (n=18) or a usual care group (n=10). The program consisted of supervised exercise 3 times/week, as well as 2 unsupervised sessions per week. The goal of our Get Fit for the Fight® program was to complete 150 min/week of moderate-intensity aerobic exercise. Participants completed a 3-day diet record during baseline testing and the dietitian recommended ways to cut calories from these typical eating patterns. The goal of caloric restriction was to decrease dietary fat in order for the participant to consume 200 kcal/week less. Assessments included aerobic fitness, body composition, and self-reported physical activity, mood and quality of life. Blood cytokines and obesity-related adipokines were also analyzed before and after the intervention period. The intervention group lost an average of 2% body fat compared with the control group (p&lt;0.01). Significant (p&lt;0.05) decreases were seen in the intervention group for body weight, BMI, and all skinfold measures except mid-axillary. Self-reported physical activity and breast-cancer specific quality of life also improved significantly in the intervention group from baseline to 12 weeks, indicating a shift from inactivity toward increasing time spent in moderate physical activity, primarily during weekends. No significant associations were observed between the intervention group and serum levels of inflammatory cytokines. However, BMI was significantly correlated (p&lt;0.05) with serum leptin/adiponectin ratios, an indicator of insulin resistance. These findings indicate that a pragmatic lifestyle intervention with physical activity and healthy eating were consistent with improvements in body composition, functional capacity and quality of life for triple-negative breast cancer survivors. The intervention also evoked favorable changes in blood leptin/adiponectin ratios which are linked to reductions in central adiposity and improved insulin sensitivity.

Citation Format: Linda Vona-Davis, Jame Abraham, Daniel Bonner, Diana Gilleland, Gerald Hobbs, Sobha Kurian, Mary Anne Yanosik, Anne Swisher. Effect of a 12-week supervised physical activity and healthy eating program on body weight, functional capacity and serum biomarkers in survivors of triple-negative breast cancer: A randomized, controlled trial [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-09-12.

"Don't know" and accuracy of breast cancer risk perceptions among Appalachian women attending a mobile mammography program: implications for educational interventions and patient empowerment

Risk perceptions are motivating factors for engaging in preventive health behaviors. Yet, almost one third of women attending a mobile mammography program targeted to rural and medically underserved Appalachian women respond "don't know" to their perceived 5-year risk of breast cancer. This study used cross-sectional data from women aged >40 years participating in Bonnie's Bus Mammography Screening and Preventive Care Survey from 2009 to 2011 to identify factors associated with "don't know" responses and accuracy of perceived risk according to constructs of the health belief model and sociodemographic characteristics. Women who responded "don't know" were more likely to be less educated, of lower income, insured by Medicaid, and less knowledgeable about breast cancer. Conversely, women who accurately perceived their risk were more likely to be of higher education, more knowledgeable about breast cancer, and have a family history of breast cancer. However, women with a high objective 5-year risk of breast cancer and older age at childbirth or were nulliparous were less likely to accurately perceive their risk. These findings suggest that women who indicate "don't know" responses and hold inaccurate risk perceptions are a population vulnerable to health disparities and may benefit from educational interventions focused on improving breast cancer knowledge and perceptions to empower them to take an active role in their preventive health and make informed decisions based on their individual level of risk.

Biochemical and molecular mechanisms for the association between obesity, chronic inflammation, and breast cancer

Upper body obesity is a risk factor for postmenopausal breast cancer and is related to an aggressive tumor phenotype and a poor prognosis regardless of menopausal status. After the menopause, the major mechanism for the association with disease risk is elevated estrogen production by adipose tissue, due to a high level of aromatase activity: these hormone-dependent tumors express both estrogen and progesterone receptors. Other important biological factors of risk include leptin and adiponectin, adipokines with opposing endocrine and paracrine activities, and obesity-related hyperinsulinemia. Chronic inflammation of the breast adipose tissue, which occurs in some obese women and is indicated by the accumulation of macrophages around dead adipocytes ("crown-like structures"), rather than adiposity per se, may prove to be the pathological lesion responsible for both local aromatase induction, and enhanced invasiveness and metastatic capacity through biological mechanisms that involve leptin, tumor necrosis factor-α, and insulin. A causal association between obesity in premenopausal women and breast cell epithelial-mesenchymal transition, perhaps with the participation of the Wnt signaling pathway, and aggressive hormone-independent breast cancer is suggested by a number of experimental and clinical studies.

Abstract P6-01-01: Diet-induced obesity increases tumor growth and promotes angiogenesis in a murine model of breast cancer

Recent epidemiological studies provide strong evidence suggesting obesity is a risk factor in several cancers, including breast cancer. However, the exact molecular mechanisms by which obesity increases the risk of breast cancer are poorly understood. In this study, we evaluated the effect of diet-induced obesity on breast carcinogenesis in the MMTV-PyMT breast cancer model. Four-week old, female mice (n = 40) were randomized to high fat (HFD) or low fat (LFD) diets for 8 weeks. Body weights were obtained weekly and mice were imaged for mammary tumor volumes by 3D ultrasound. Tumor burden was collected during early and late stages, weighed and fixed for immunohistochemical staining. Blood and tissue from the liver, lung, and mesenteric fat were also collected. We also compared the basal VEGF protein expression in skeletal muscle, adipose tissue and mammary tumors from MMTV-PyMT mice and compared these levels against background nontransgenic FVB/N mice. Average tumor volumes and tumor burdens were markedly greater in the mice fed HFD than in LFD and showed an increased number of metastases to the lung by 2-fold. HFD increased mammary cell proliferation and elevated Chemokine (C-C motif) ligand 2 (CCL2) in the blood, tumor beds and adipose tissue. Histopathological analysis showed more tumor-associated macrophages and increased microvessel density with diet-induced obesity. Significantly more crown-like structures were evident in adipose tissue from obese mice at both early and late stage carcinoma. Adipose tissue of MMTV-PyMT mice exhibited greater VEGF protein expression compared to adipose tissue of control FVB mice, and greater VEGF protein compared to tumor VEGF expression. Our findings demonstrate that diet-induced obesity exacerbates breast cancer progression in MMTV-PyMT mice and suggests that high body adiposity caused by diet-induced changes promotes an inflammatory and angiogenic phenotype in breast cancer. NIH P20 RR016440, P30 R032138 and GM103488, and P20 RR016477.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-01-01.

The obesity-inflammation-eicosanoid axis in breast cancer

Inflammation of the adipose tissues occurs in association with obesity. This inflammatory process leads to the induction of cyclooxygenase-2 (COX-2) expression and a consequent elevation in prostaglandin (PG) production, which, together with proinflammatory cytokines, induce aromatase expression and estrogen synthesis. Infiltrating macrophages support the growth of breast epithelial cells and vascular endothelial cells by producing a milieu of cytokines and growth factors. This scenario creates a microenvironment favorable to breast cancer growth and invasion. The eicosanoids promote further development and growth of breast cancers indirectly by the induction of aromatase, particularly in estrogen positive breast cancers, or by direct stimulatory effect of PGE2 and lipoxygenase (LOX) products on the more aggressive, estrogen-independent tumors. Beyond this, the local production of estrogens and proinflammatory cytokines which occurs in association with breast adipose tissue inflammation, and consequent activation of the estrogen receptor and nuclear factor-κB, provides a mechanism by which breast cancers develop resistance to selective estrogen receptor modulation and aromatase inhibitor therapy. The obesity-inflammation-eicosanoid axis in breast cancer does offer a therapeutic target for the prevention of relapse in breast cancer by improving the efficacy of antiaromatase therapy using COX/LOX inhibitors; however, careful consideration of menopausal status and obesity in patients is warranted.

Abstract 1549: Diet-induced obesity increases tumor levels of MCP-1, macrophage infiltration and microvessel density in a murine model of breast cancer

Epidemiological studies indicate that obesity is associated with poor outcomes in breast cancer. In our previous work, we demonstrated that a chronic consumption of a high fat diet increases solid tumor growth and metastasis in a spontaneous mammary cancer mouse model. In addition to higher tumor burdens and rates of metastases, mice fed a high fat diet showed elevated levels of adipocyte derived monocyte chemoattractant protein-1 (MCP-1) in the blood. We hypothesized that diet-induced obesity promotes mammary carcinogenesis by inducing an inflammatory and tumor-supportive microenvironment. We further compared chow fed lean MMTV(PyMT) mice with those fed 45.0% (w/w) high fat (HF) to investigate the impact of body adiposity and dietary nutrient overload on levels of MCP-1 in tissue, tumor associated macrophages (TAMs) and for the degree of microvessel density. We analyzed early and late carcinoma stage tumors together with adipose tissue from mice fed HF and control diets in order to identify possible sources of MCP-1 production. MCP-1 levels in tumors of mice differed significantly by cancer stage and diet, with late stage tumors showing more MCP-1 (P&lt;0.05). Moreover, MCP-1 production was elevated in adipose tissue of obese mice compared to lean mice. Tumors and adjacent adipose were stained with CD68 and the numbers of TAMs were quantified. Significantly more TAMs (P&lt;0.05) were found within tumor beds and more crown-like structures were evident in adipose tissue from obese mice at both early and late stage carcinoma. Tumor beds also showed increased microvessel density when stained with CD31. In summary, diet-induced obesity increased levels of MCP-1 in tumors and adipose with more macrophage infiltration and greater vascular density evident in mammary tumor beds. Taken together, these findings suggest that high body adiposity caused by diet-induced changes promote an inflammatory and tumor-supportive microenvironment in breast cancer. NIH P20 RR016440, P30 R032138/GM103488, and P20 RR016477

Citation Format: Emily Ngan, Alessandra Pacilli, Eva Marshall, Kirstie Cutlip, James Coad, Amanda Ammer, Linda Vona-Davis. Diet-induced obesity increases tumor levels of MCP-1, macrophage infiltration and microvessel density in a murine model of breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1549. doi:10.1158/1538-7445.AM2013-1549

The cellular and molecular mechanisms by which insulin influences breast cancer risk and progression

Epidemiological studies have related hyperinsulinemia and type 2 diabetes to an increased breast cancer risk, an aggressive and metastatic phenotype, and a poor prognosis. Furthermore, diabetic retinopathy arises from pathological angiogenesis, which is also essential for breast cancer growth and metastasis. Insulin stimulates the proliferation of some human breast cancer cell lines in vitro by mechanisms that use both the phosphatidylinositol-3 kinase and the mitogen-activated protein kinase/Akt signaling pathways; it is also a cell survival (anti-apoptotic) agent and enhances tumor cell migration and invasive capacity. Hyperinsulinemia affects breast cancer cells via the endocrine system, but experimental studies suggest the importance of paracrine mechanisms operating by the effects of insulin on the secretion of adipokines from tumor-associated adipose tissue. In such a system, one adipokine, leptin, has stimulatory paracrine effects on breast cancer cell proliferation and survival, while a second, adiponectin, is inhibitory. Leptin, vascular endothelial growth factor, another insulin-regulated adipokine, and insulin itself also stimulate angiogenesis. Insulin has complex interactions with estrogens: it induces adipose stromal cell aromatase and tumor cell sex steroid hormone receptor expression and suppresses sex hormone-binding globulin, which may enhance estrogen synthesis and bioactivity with consequent promotion of estrogen-dependent breast cancer. All these actions influence the later steps in breast cancer development but genetic studies are also revealing connections between gene abnormalities related to type 2 diabetes and the initiation stage of breast carcinogenesis. Understanding the various mechanisms by which insulin participates in breast cancer cell biology provides opportunities for novel approaches to treatment.

Factors influencing adherence to mammography screening guidelines in Appalachian women participating in a mobile mammography program

The objectives of this study were to evaluate the characteristics (demographic, access to care, health-related behavioral, self and family medical history, psychosocial) of women age 40 years and above who participated in a mobile mammography screening program conducted throughout West Virginia (WV) to determine the factors influencing their self-reported adherence to mammography screening guidelines. Data were analyzed using the Andersen Behavioral Model of Healthcare Utilization framework to determine the factors associated with adherence to mammography screening guidelines in these women. Of the 686 women included in the analysis, 46.2% reported having had a mammogram in the past 2 years. Bivariate analyses showed predisposing factors such as older age and unemployed status, visit to a obstetrician/gynecologist (OB/GYN) in the past year (an enabling factor) and need-related factors such as having a family history of breast cancer (BC), having had breast problems in the past, having had breast biopsy in the past, having had a Pap test in past 2 years, and having had all the screenings for cholesterol, blood glucose, bone mineral density and high blood pressure in past 2 years to be significant predictors of self-reported adherence to mammography guidelines. In the final model, being above 50 years (OR=2.132), being morbidly obese (OR=2.358), having BC-related events and low knowledge about mammography were significant predictors of self-reported adherence. Breast cancer related events seem to be associated with mammography screening adherence in this rural Appalachian population. Increasing adherence to mammography screening may require targeted, community-based educational interventions that precede and complement visits by the mobile mammography unit.

Type 2 diabetes and obesity metabolic interactions: common factors for breast cancer risk and novel approaches to prevention and therapy

The objective was to review type 2 diabetes as a risk factor for breast cancer, its influence on tumor aggressiveness and prognosis, and the interactions with obesity. Consideration was given to the responsible biological mechanisms and how these relate to the potential of hypoglycemic agents, notably metformin, as breast cancer chemotherapeutic agents. Most epidemiological studies indicate that type 2 diabetes is a modest positive risk factor for postmenopausal, but not premenopausal, breast cancer; indeed before the menopause it may be associated with a reduced risk. This pattern of differing effects on risk according to menopausal status is well established in obesity; however, although most type 2 diabetics are obese, the relationship with postmenopausal breast cancer does not appear to be a function of the body mass index. We suggest that before menopause the protective effect of obesity may modify any adverse effects of the metabolic changes related to type 2 diabetes. Regardless of menopausal status, obesity is associated with breast cancers that exhibit aggressive biological characteristics at the time of diagnosis and have a poor prognosis; a similar relationship is emerging for type 2 diabetes. The two metabolic disorders share biological mechanisms for their associations with breast cancer, including a direct effect of insulin on breast cancer cell proliferation, increased extraglandular estrogen production and bioavailability, changes in the adipokines, notably adiponectin, and activation of the AMP-activated protein kinase pathway. These mechanistic considerations are consistent with metformin having high potential as a breast cancer chemopreventive and therapeutic agent.

Abstract B83: Factors influencing adherence to mammography screening guidelines in Appalachian women participating in a mobile mammography program

Objectives: The objectives of this study were to evaluate the characteristics (demographic, access to care, health-related behavioral, self and family medical history, psychosocial) of women age 40 years and above who participated in a mobile mammography screening program conducted throughout West Virginia to determine the factors influencing their self-reported adherence to mammography screening guidelines.

Methods: The data were collected from 738 women who participated in the Bonnie Wells Wilson Mobile Mammography Program and completed a six-page Preventive Care Survey. Data were analyzed using the Andersen Behavioral Model of Healthcare Utilization framework to determine the factors associated with adherence to mammography screening guidelines in these women.

Results: Of the 686 women included in the analysis, 46.2% reported having had a mammogram in the past two years as per current mammography screening guidelines. The unadjusted model showed predisposing factors such as older age and unemployed status, visit to a gynecologist in the past year (an enabling factor) and need-related factors such as having a family history of breast cancer (BC), having had breast problems in the past, having had breast biopsy in the past, having had a Pap test in past two years, and having had all the screenings for cholesterol, blood glucose, bone mineral density and high blood pressure in past two years to be significant predictors of self-reported adherence to mammography guidelines. In the adjusted model, being of age 65 and above (OR=3.787), having a family history of BC (OR=1.909), having had breast problems in the past (OR=1.992) and having had a Pap test (OR=6.035) were significant predictors of self-reported mammography screening adherence.

Conclusions: Forty-six percent of the sample reported having had a mammogram in the past two years as per current mammography screening guidelines which is lower than the 70% goal of Healthy People 2010. Breast cancer related events seem to be associated with mammography screening adherence in this rural Appalachian population. Increasing adherence to mammography screening may require targeted, community-based educational interventions that precede and complement visits by the mobile mammography unit.

Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):B83.

Abstract 1213: Neuropeptide Y, adipose tissue and breast cancer

Adipose tissue contributes to obesity-associated risk in breast cancer progression. Recent work has demonstrated the involvement of preadipocytes in promoting the induction of breast tumor cell migration and invasion. Neuropeptide Y (NPY) stimulates proliferation of preadipocytes in vitro by the Y1 receptor. NPY receptors are present in almost all primary breast cancers and in lymph node metastases from ER-positive primary cancers. By contrast, the peptide has been shown to inhibit the invasion of certain tumor cells. However, the relative contribution of adipose and NPY to breast tumor survival remains to be determined. Using the highly metastatic ER-negative human breast cancer cell line MDA-MB-231, we found that NPY significantly inhibited cell proliferation, an effect that was reversed by treatment with the Y1-receptor antagonist BIBP-3226 (P&lt;0.05). Breast tumor cells treated with NPY exhibited changes in cell morphology and demonstrated a two-fold increase in early apoptosis. When breast tumor cells were incubated in the presence of conditioned media harvested from 3T3-L1 preadipocytes, NPY enhanced apoptosis. Significantly more breast tumor cells migrated toward the preadipocytes compared to conditioned media alone (P&lt;0.0001), but less in the presence of NPY. In conclusion, it appears that adipose tissue promotes breast tumor survival and migration, while NPY limits its. It will be of interest to determine whether the tumor migration-promoting activity of preadipocytes varies among breast cancer subtypes, and if so, whether it serves as a predisposing factor for breast cancer progression. In addition, the targeting of NPY-Y1 receptors in breast tumors may have a diagnostic and possibly therapeutic value.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1213. doi:10.1158/1538-7445.AM2011-1213

Abstract PD09-03: Disease Outcomes in Primary Breast Cancer Are Associated with Obesity, Lymph Node Status and Angiolymphatic Invasion

Background: Obesity is associated with higher rates of breast cancer and poorer survival. Our previous work has shown that lymph node metastases are more frequently associated with advanced disease in obese patients. We sought to investigate the association of obesity with angiolymphatic invasion on disease outcomes in patients with invasive breast cancer. Methods: This retrospective study involved 627 predominately white women with invasive breast cancer. Hospital tumor registry, charts, and pathology records provided demographics and tumor biologic features. Body mass index (BMI) values were categorized according to WHO criteria: normal or underweight (lean), &lt; 25.0 kg/m2; overweight, 25.0 to 29.9 kg/m2; obese, 30.0 kg/m2 or higher. Univariate and multivariate analyses were conducted between BMI and clinical outcomes, controlling for menopausal status. Recurrence-free survival and overall survival were calculated and a log-rank test was used to determine significance between groups.

Results: In our study cohort, 175 (27.9%) were normal weight, 211 (33.7%) overweight and 241 (38.4%) were considered obese. Greater lymph node involvement and angiolymphatic invasion (P = 0.04) were present with obesity. Triple-negative tumors were more common in those patients classified as overweight and obese (43%) compared to normal weight individuals (20%). Factors associated with BMI were tumor size and lymph node status. In postmenopausal women, obesity was associated with an increased risk of lymph node metastases (OR 1.81, 95% CI 1.14-2.91; P = 0.010) and angiolymphatic invasion (OR 2.09, 95% CI 1.01-4.72; P = 0.049) when compared with normal weight individuals. The probability of developing a relapse within 10 years was higher among women with BMI ≥30.0 with positive lymph nodes and the presence of angiolymphatic invasion.

Conclusions: In obese women with breast cancers, higher rates of lymph node involvement and angiolymphatic invasion may explain poorer outcomes. These findings further support the relationship between obesity and the factors that are elaborated by adipocytes as instrumental in promoting a more aggressive growth and progression of breast cancer.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD09-03.

Predominance of Brain and Lung Metastases in Triple-Negative Breast Cancer Patients

Background: Patients with triple-negative breast cancer have an increased likelihood of recurrence compared to other types of breast cancer, however, little is known about their pattern of metastatic spread. Our object was to evaluate the metastatic patterns of women diagnosed with triple-negative breast cancer compared to other subtypes. Methods: We studied a cohort of 572 white patients diagnosed with invasive breast cancer at West Virginia University Hospital between 1999 and 2004. Hospital registry, charts, and pathology records provided clinical data including tumor receptor status and biopsy-proven metastatic spread to bone, brain, liver and lung. Breast cancers that were negative for estrogen, progesterone, and HER2neu, otherwise known as triple-negative were compared with HER2neu-postive and HER2neu-negative (endocrine receptor positive) disease. Body mass index was calculated and a value of ≥30 considered indicative of obesity. Specimens of primary carcinoma were available for analysis of Ki67 mitotic index and expression of p53. Results: 134/572 (23.4%) had triple-negative breast cancer, while the frequencies were 108/572 (18.9%) and 330/572 (57.7%) in HER2neu-positive and HER2neu-negative (endocrine receptor positive) groups. Women with triple-negative disease were more likely to have brain-metastasizing breast cancer; 10.5% versus 4.6% for HER2neu-positive and 3.3% for HER2neu-negative (P&lt;0.05). They were also more likely to have metastasis to the lung; 10.5% versus 2.8% for HER2neu-positive and 7.0% for HER2neu-negative (P&lt;0.05). Triple-negative breast cancer patients who developed brain and lung metastases were younger &lt;50 years and significantly more obese (P=0.0236). High Ki67 labeling index and p53 expression were associated with more advanced disease indicating an aggressive phenotype for this group.Patterns of metastasis in breast cancer subtypesSite of metastasisTriple-negativeHER2-positiveHER2-negativeP valueBone20/134 (14.9)7/108 (6.5)38/330 (11.5)0.1037Brain14/134 (10.5)5/108 (4.6)11/330 (3.3)0.0136*Liver11/134 (8.2)4/108 (3.7)22/330 (6.7)0.3261Lung14/134 (10.5)3/108 (2.8)23/330 (6.9)0.0507*Other5/134 (3.7)3/108 (2.8)3/330 (0.91)0.1093 Conclusion: The excess risk of brain and lung metastasis in women with triple-negative breast cancers versus other subtypes needs further validation. The unique biology of triple-negative tumors may explain this pattern of metastatic spread.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6159.

Triple-negative breast cancer in West Virginia

In 2007, the American Cancer Society ranked West Virginia 43rd in breast cancer incidence rates for individual states. Despite our improvements in medical care, the advanced pathological characteristics of breast cancer at diagnosis receive little attention. Consequently, we compared the changing pattern of early breast cancer in several cohort studies conducted at regional medical centers in West Virginia. The data used in this analysis was derived from 320 women presenting at West Virginia University Hospital (WVUH) in Morgantown between 1999 and 2004, with a diagnosis of invasive breast cancer. Details of age, tumor size and axillary lymph node status were compared with tumor registry information published from a cohort study of 191 patients from the Charleston Area Medical Center (CAMC) between 1990 and 1991. Only histologically documented adenocarcinomas of the breast were included. Tumor size was characterized using the TNM system and staged according to AJCC criteria. For comparative purposes, details from the two regional centers were compared with tumor characteristics from a large longitudinal cohort of 2,484 breast cancers from the Women's Health Initiative (WHI) study. Baseline median age at diagnosis of women screened at WVUH was younger than patients at CAMC (52 vs. 60). Women diagnosed with triple-negative breast cancer at WVUH and CAMC had similar age distributions. Within the triple-negative patients at WVUH, 44% of patients were less than 50 years of age and 20% were less than 40 years of age. At CAMC, 35% were less than 50 years of age and 7% were less than 40 years of age. For women at WVUH, 61.5% presented with T1 tumors compared to 65.5% at CAMC. These figures were lower than the WHI average of 80.3%. In contrast, more women presented with larger T2 tumors at our medical centers compared with the national study, 32.6% versus 17.4% respectively. At WVUH, 2.3% of women had T3 tumors (> or =5 cm) compared with 1% at CAMC. Similar to the WHI study, 35-42% of women at WVUH and CAMC were diagnosed at the T1c stage. Approximately, 30% were diagnosed with positive lymph nodes, compared to 23% in the national study. Combined breast cancer data from our medical centers show an increase in more advanced tumors and positive regional lymph node involvement at the time of diagnosis compared to national reports. Other factors such as obesity, diabetes, poverty and access to mammography screening could be influencing the poorer outcomes for women with breast cancer in West Virginia.

Angiogenesis, adipokines and breast cancer

The prevalence of overweight and obesity is rapidly increasing world wide. Numerous epidemiological studies have shown that obesity is a risk factor for postmenopausal breast cancer and relapse. However, the biological factors that drive the growth and progression of these tumors and how obesity contributes to the tumor microenvironment are poorly understood. Tumor development and metastasis are dependent on the process of angiogenesis or the formation of new blood vessels. More importantly, a ready supply of adipose tissue-derived angiogenic adipokines, notably VEGF and leptin, and the production of inflammatory cytokines by infiltrating macrophages that occurs in adipose tissues with obesity, promotes the paracrine stimulation of vascular endothelial cell growth needed for adipogenesis, while maintaining a microenvironment that is favorable for breast tumorigenesis.

Triple-negative breast cancer and obesity in a rural Appalachian population

BACKGROUND

Our objective was to determine the clinicopathologic features of triple-negative (estrogen receptor, progesterone receptor, and human epidermal growth factor-2 receptor negative) breast cancer and their relationship to obesity in women drawn from a population with one of the highest obesity rates in the United States.

METHODS

This retrospective study involved 620 White patients with invasive breast cancer in West Virginia. Hospital tumor registry, charts, and pathology records provided age at diagnosis, tumor histologic type, size, nodal status, and receptor status. Body mass index was calculated and a value of > or = 30 was considered indicative of obesity.

RESULTS

Triple-negative tumors occurred in 117 (18.9%) of the 620 patients, most often in association with invasive ductal carcinomas. Patients with triple-negative tumors were younger than those with other receptor types, 44.5% and 26.7%, respectively, being diagnosed at age <50 years (P = 0.0004). The triple-negative tumors were larger (P = 0.0003), most notably in the younger women, but small tumors (<2.0 cm) were more often accompanied by lymph node metastases. Obesity was present in 49.6% of those with triple-negative tumors but in only 35.8% of those with non-triple-negative tumors (P = 0.0098). Lymph node metastases were more frequently associated with T(2) tumors in obese patients (P = 0.032) regardless of their receptor status.

CONCLUSIONS

Triple-negative breast cancers within a White, socioeconomically deprived, population occurred in younger women, with later stage at diagnosis, and in association with obesity, which itself has been associated with a poor prognosis in breast cancer.

Triple-negative breast cancer and obesity in a rural Appalachian population

Abstract #6099

Background: Our objective was to determine the clinico-pathological features of triple-negative (estrogen, progesterone and HER-2 receptor negative) breast cancer and their relationship to obesity in women drawn from a population with one of the highest obesity rates in the United States.&#x2028; Methods: This retrospective study involved 620 white patients with invasive breast cancer in West Virginia. Hospital tumor registry, charts, and pathology records provided age at diagnosis, tumor histologic type, size, and nodal status, and receptor status. Body mass index (BMI) was calculated and a value of ≥30 considered indicative of obesity.&#x2028; Results: Triple-negative tumors occurred in 117 (18.9%) of the 620 patients, most often in association with invasive ductal carcinomas. Patients with triple-negative tumors were younger than those with other receptor types, 44.5% and 26.7%, respectively, being diagnosed before age 50 years (P = 0.0004). The triple-negative tumors were larger (P = 0.0003), most notably in the younger women, but small tumors (&lt;2.0 cm) were more often accompanied by lymph node metastases. Obesity was present in 49.6% of those with triple-negative tumors, but only 35.8% of those with non-triple-negative tumors (P = 0.0098). Lymph node metastases were more frequently associated with T2 tumors in obese patients (P = 0.032) regardless of their receptor status.&#x2028; Conclusions: Triple-negative breast cancers within a white, socioeconomically-deprived, population occurred in younger women, with later stage at diagnosis, and in association with obesity. The elevated adipokine production which is present in obesity may exert tumor proliferative and angiogenic effects that contribute to an aggressive phenotype.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6099.

Adiposity, type 2 diabetes and the metabolic syndrome in breast cancer

Upper body obesity and the related metabolic disorder type 2 diabetes have been identified as risk factors for breast cancer, and associated with late-stage disease and a poor prognosis. Components of the metabolic syndrome, including visceral adiposity, insulin resistance, hyperglycemia and hyperinsulinemia, with or without clinically manifest diabetes mellitus, low serum high-density lipoprotein cholesterol and hypertension have all been related to increased breast cancer risk. The biochemical mechanisms include extraglandular oestrogen production, reduced sex hormone-binding globulin with consequent elevation of the bioactive plasma free oestradiol and increased insulin biosynthesis, all of which exert mitogenic effects on both untransformed and neoplastic breast epithelial cells. Obesity, type 2 diabetes and the metabolic syndrome also have in common an increased production of leptin and a decreased production of adiponectin by adipose tissue, with consequent elevations and reductions, respectively, in the circulating levels of these two adipokines. These changes in plasma leptin and adiponectin, acting through endocrine and paracrine mechanisms, have been associated in several studies with an increase in breast cancer risk and, perhaps, to more aggressive tumours; studies in vitro showed that leptin stimulates, and adiponectin inhibits, tumour cell proliferation and the microvessel angiogenesis which is essential for breast cancer development and progression.

Phenotypic characteristics of triple negative breast cancer in a rural population

17060

Background: Triple negative breast tumors are a basal-like subtype of breast cancer associated with the poorest clinical outcomes. Typically they are found in younger patients, African-American women, and patients with the BRCA mutation. To date, however, the epidemiology of triple negative breast cancers in a rural, Caucasian population has not been described. Methods: 96 breast cancer patients presenting with a basal-like subtype of breast cancer had tumor biopsies and demographic and epidemiologic information were collected. Standard histologic and immunohistochemical analysis was done for ER, PR, HER-2/neu status for all high nuclear grade tumors from January 2000 to December 2005 at West Virginia University Hospital. The tumor registry was reviewed to determine tumor size, stage at diagnosis, age at diagnosis, race, menopausal status, body mass index (BMI) and BRCA1/BRCA2 status. Variables in the triple negative group were then compared to all patients who were diagnosed with infiltrating ductal carcinoma between 1999–2004. Results: The basal-like breast cancer subtype was more prevalent among the 40–59 year old group (52%, 50/96) versus women <40 years (12.5%, 12/96) (p= 0.01). Most patients presented with T2 tumors (57%) and the majority had stage II disease (61%, p-value = 0.01). 67% of the population was postmenopausal and were more likely to be overweight or obese (73%, p-value = 0.03). Only one African-American patient met all criteria (2.8%). Of the 7 patients with triple negative tumors who received BRCA testing, four were BRCA1 positive. Age, tumor stage and BMI were similar between the populations of triple negative tumors and infiltrating ductal carcinoma. Conclusions: The demographic and phenotypic characteristics of basal-like breast cancers are still being defined. In contrast to previous findings, triple negative tumors in a rural area were found in middle aged, postmenopausal Caucasian women with Stage II disease and a higher BMI. This analysis will help to identify possible risk factors such as obesity in triple negative cancer subtypes and may prompt further research into differences in breast cancer survival in obese populations from rural areas.

No significant financial relationships to disclose.

Adipokines as endocrine, paracrine, and autocrine factors in breast cancer risk and progression

Adipokines (leptin, adiponectin, and hepatocyte growth factor (HGF)) secreted from adipose tissue have come to be recognized for their contribution to the mechanisms by which obesity and related metabolic disorders influence breast cancer risk. In this review, we discuss the direct and indirect effects of these protein factors on the biological and clinical aspects of breast cancer biology, and emphasize their distinctive modes of action through endocrine-, paracrine-, and autocrine-mediated pathways. The stimulatory effects of leptin on breast cancer growth were considered to occur primarily via activation of the estrogen receptor; however, new evidence suggests that leptin may be acting on downstream cell signaling pathways in both estrogen-dependent and -independent cell types. Another secretory adipokine, HGF, may act largely not only to promote tumor cell invasion, but also to enhance tumor growth indirectly by stimulating angiogenesis. In contrast, adiponectin, an endogenous insulin sensitizer, exerts a direct growth-inhibitory effect on tumor cells by downregulating cell proliferation and upregulating apoptosis, and also inhibits tumor-related angiogenesis.

PYY and the pancreas: inhibition of tumor growth and inflammation

Peptide YY (PYY) orchestrates function of the gut and pancreas by regulating growth, digestion and absorption. In addition to its physiological role, PYY exhibits immune and antitrophic properties in the pancreas by decreasing cytokine and amylase release. Although the exact mechanism(s) of action are still not fully understood, PYY interacts at the acinar level with numerous intracellular transcription factors. In addition to ameliorating pancreatic inflammation, novel synthetic analogs of PYY have been developed that are potent inhibitors in the proliferation of pancreatic cancer. The present paper reviews our current findings with PYY and examines the therapeutic implications of its utility in treating inflammation and cancer.

Peptide YY Reverses TNF-α Induced Transcription Factor Binding of Interferon Regulatory Factor-1 and p53 in Pancreatic Acinar Cells

BACKGROUND

Cytokine activation in the pancreatitis induces local and systemic cellular damage. Transcription factors interferon regulatory factor-1 (IRF-1) and the tumor suppressor gene p53 collaborate to enhance p21 related cell cycle regulation during pathological disease progression. However, little is known about their role in the pancreas after cytokine challenge. Our laboratory has previously shown that TNF-alpha induces the binding of many transcription factors, including NF-kappa B, and treatment with the gut hormone, Peptide YY (PYY), ameliorates the effects. We hypothesized that TNF-alpha would induce IRF-1 and p53 protein binding in pancreatic acinar cells and that PYY would attenuate the effect.

MATERIALS AND METHODS

Rat pancreatic acinar AR42J cells were treated with rat recombinant TNF-alpha (200 ng/ml). To verify that our model was inducing pancreatitis, alpha-amylase activity was measured in the cell culture supernatant by fluorescence spectroscopy. PYY [3-36] was added at 500 pM 30 min post-TNF treatment; cells were harvested at 2 h for extraction of nuclear protein. Transcription factor binding of IRF-1 and p53 were determined by protein/DNA array analysis using chemiluminescence detection, and relative spot densities were measured by densitometry. A two-fold increase or decrease in density was considered significant.

RESULTS

Amylase enzyme activity was significantly (P < 0.05) elevated in the TNF-alpha-treated cells by 2 h. Protein/DNA array analysis revealed significant up-regulation of both IRF-1 and p53 protein in nuclear extracts. Induction by TNF-alpha increased IRF-1 protein binding 3.5-fold, while binding levels of p53 protein increased six-fold. The addition of PYY to TNF-treated cells reduced IRF-1 and p53 binding to control levels.

CONCLUSIONS

We have shown for the first time that short-term exposure to TNF-alpha induces the binding activity of transcription factors IRF-1 and p53 in rat pancreatic acinar cells, and that addition of PYY reduces it. Regulation of transcription factor activity by PYY may have therapeutic potential in altering the progression of pancreatitis.

Peptide YY attenuates STAT1 and STAT3 activation induced by TNF-alpha in acinar cell line AR42J

BACKGROUND

STAT1 and STAT3, members of the cytoplasmic family of signal transducers and activators of transcription factors (STAT), have been associated with numerous inflammatory pathologies, including inflammatory bowel disease, hepatitis, and acute lung injury. But little is known about their role in the pancreas. Peptide YY (PYY), an inhibitory gastrointestinal hormone, ameliorates pancreatitis in vivo and in vitro. In addition, we have shown that PYY attenuates transcription factors, such as nuclear transcription factor (NF)-kappaB and Smad3/4, which mediate inflammation. We hypothesized that tumor necrosis factor (TNF)-alpha would induce STAT1 and STAT3, and PYY would attenuate their transcription factor binding.

STUDY DESIGN

Rat pancreatic acinar cells were treated with recombinant TNF-alpha (200 ng/mL); PYY (3-36; 500 pM) was added 30 minutes post-TNF-alpha treatment. Cells were harvested at 2 hours, and nuclear protein and conditioned media were extracted. Levels of amylase secretion and cytokine production were measured using commercially available kits. STAT transcription factor binding was determined by protein/DNA array analysis and densitometry; results were verified again by electrophoretic mobility shift assay (EMSA) and ELISA-based assay.

RESULTS

Amylase production was considerably increased (p < 0.05) as early as 5 minutes after addition of exogenous TNF-alpha and remained elevated for 24 hours. PYY decreased amylase production to control levels. A notable increase (p < 0.05) in the production of cytokines interleukin (IL)-1beta, IL-4, IL-6, IL-10, and TNF-alpha was observed with TNF-alpha treatment; production was reduced with PYY. TNF-alpha substantially upregulated STAT1 and STAT3 (two-fold or greater); PYY downregulated their binding activity to control levels. Results from both the electrophoretic mobility shift assay- and the ELISA-based assays verified STAT1 and STAT3 responses to TNF-alpha and PYY.

CONCLUSIONS

In pancreatic acinar cells, TNF-alpha activated STAT1 and STAT3, known mediators of inflammatory cytokines. Interestingly, PYY attenuated their protein/DNA binding, which may have an impact on development of the disease. Additional investigation of STAT proteins and PYY could provide new therapeutic strategies for pancreatitis.

Inositol hexaphosphate (IP6): a novel treatment for pancreatic cancer

BACKGROUND

Inositol hexaphosphate (IP6) is a naturally occurring polyphosphorylated carbohydrate found in food sources high in fiber content. IP6 has been reported to have significant inhibitory effects against a variety of primary tumors including breast and colon. The effects of IP6 have not been evaluated in pancreatic cancer. We hypothesized that IP6 would significantly inhibit cell growth and increase the apoptotic rate of pancreatic cancer in vitro.

MATERIALS AND METHODS

Two pancreatic cancer cell lines (MIAPACA and PANC1) were cultured using standard techniques and treated with IP6 at doses of 0.5, 1.0, and 5.0 mm. Cell viability was measured by MTT at 24 and 72 h. Apoptosis was evaluated by Annexin V-FITC and results calculated using FACS analysis. Statistical analysis was performed by ANOVA.

RESULTS

Significant reductions (P < 0.01) in cellular proliferation were observed with all IP6 concentrations tested in both cell lines and at both time points. Reductions in cell proliferation ranged from 37.1 to 91.5%. IP6 increased early and late apoptotic activity (P < 0.01).

CONCLUSIONS

Treatment of pancreatic cancer with the common dietary polyphosphorylated carbohydrate IP6 significantly decreased cellular growth and increased apoptosis. Our findings suggest that IP6 has the potential to become an effective adjunct for pancreatic cancer treatment. Further in vivo and human studies are needed to evaluate safety and clinical utility of this agent in patients with pancreatic cancer.

In vitro effects of keyhole limpet hemocyanin in breast and pancreatic cancer in regards to cell growth, cytokine production, and apoptosis

BACKGROUND

We have previously shown the inhibitory effects of keyhole limpet hemocyanin (KLH) against breast and pancreatic cancer in vitro. We hypothesize that its actions in breast and pancreas cancer cells are via apoptotic or cytokine pathways.

METHODS

Two breast cancer cell lines, ZR75-1 and MCF-7, and one pancreas cancer cell line, PANC-1, were treated with KLH at 500 mug, 250 mug, and 250 ng/mL. Cell viability, cytokine production, and apoptosis were measured.

RESULTS

Significant growth inhibition was observed in all cell lines at all KLH concentrations tested. Significant changes in cytokine production were observed in all cell lines. An increase in early and late apoptotic activity was observed in the MCF-7, whereas a reduction in late apoptotic activity was observed in the ZR75-1 cells.

CONCLUSIONS

KLH directly inhibits the growth of human breast and pancreas cancer in vitro by apoptotic and nonapoptotic mechanisms.

MAPK and PI3K Inhibition Reduces Proliferation of Barrett’s Adenocarcinoma in Vitro1

BACKGROUND

Esophageal adenocarcinoma often arises from Barrett's esophagus. Mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) play critical roles in cell survival. We hypothesized that inhibition of these pathways in Barrett's adenocarcinoma would decrease cell proliferation and alter apoptosis in vitro.

MATERIALS AND METHODS

Two Barrett's-associated adenocarcinoma cell lines, SEG-1 (wild-type p53) and BIC-1 (mutant p53), were treated with MAPK (U0126) and PI3K (LY294002) inhibitors at 20 microm concentrations. After 24 and 72 h, cell viability was measured by MTT assay. Apoptosis and necrosis were evaluated by the Annexin V-FITC assay. Statistical analysis was performed by ANOVA.

RESULTS

LY294002 and U0126 treatment produced significant reductions (range 15.7 to 62.0%, P < 0.05) in cellular proliferation at both 24 and 72 h in the SEG-1 cells. BIC-1 cell viability was reduced (39.3 to 56.4%, P < 0.05) at 72 h. Both early and late apoptotic activity were significantly increased (P < 0.05) in the SEG-1 cells using both inhibitors. Necrosis was significantly reduced (P < 0.05) using both inhibitors. No changes in either early or late apoptosis or necrosis were observed in the BIC-1 cells.

CONCLUSIONS

Herein, we report significant antiproliferative effects against Barrett's adenocarcinoma by MAPK and PI3K inhibition in vitro. Pro-apoptotic mechanisms prevail in the wild-type p53 cells. Further investigation is warranted to advance the clinical treatment of this devastating disease.

Proteomic analysis of SEG-1 human Barrett's-associated esophageal adenocarcinoma cells treated with keyhole limpet hemocyanin

Keyhole limpet hemocyanin (KLH) is an immune stimulant derived from a circulating glycoprotein of the marine mollusk Megathura crenulata. We previously reported that KLH inhibited the growth of human Barrett's-associated esophageal adenocarcinoma in vitro via apoptotic and nonapoptotic mechanisms. We hypothesize that KLH reduces the growth of Barrett's cancer cells by altering protein expression profiles. A cell line (SEG-1) derived from Barrett's-associated adenocarcinomas of the distal esophagus was selected. Cells were administered KLH (500 microg/ml) or vehicle. After 24 hours, cytosolic fractions were separated through two-dimensional gel electrophoresis. Statistical analysis was performed with Evolution Pro software to identify spots that were differentially expressed between the KLH and control groups. Proteins displaying a twofold or greater change in expression levels were selected for identification. In a total of 420 spots, 31 were differentially expressed between the KLH and control groups. In all, 12 were upregulated and 19 were downregulated. Of the 31, 17 were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Proteomic evaluation shows downregulation of proteins associated with metabolic processes (glycolysis, protein synthesis). KLH also induced proteins indicative of oxidative stress (heat shock 70 family and UDP-glucose 6-dydrogenase). Our results indicate that growth arrest by KLH is accompanied by a cellular stress response and attenuation of metabolic processes. The use of KLH as adjuvant or topical therapy for Barrett's adenocarcinoma provides a promising development in the treatment of this disease.

Peptide YY inhibits the growth of Barrett's esophageal adenocarcinoma in vitro

BACKGROUND

Peptide YY (PYY) is an endogenous gut hormone that inhibits the growth of certain cancers. Adenocarcinoma of the esophagus usually arises from Barrett's esophagus. We hypothesized that treatment of Barrett's adenocarcinoma with PYY would result in decreased proliferation.

METHODS

Barrett's cancer cell lines (BIC and SEG-1) were treated with PYY (3-36) at 500 pmol/mL. Viability was measured by MTT at 24 and 72 hours. Apoptosis and necrosis was evaluated by flow cytometry.

RESULTS

PYY reduced proliferation in SEG-1 cells at 24 hours (21.2% +/- 3.4%, P <0.001) and 72 hours (14.2% +/- 6.2%, P <0.001). In the BIC cells, growth was inhibited by 7.9% +/- 7.0%, P = 0.021 after 72 hours. PYY increased late apoptotic activity in SEG-1 cells by 31%, P = 0.014.

CONCLUSIONS

This is the first report of antiproliferative effects of PYY against Barrett's carcinoma in vitro. Reductions in cell growth appear to be mediated by proapoptotic mechanisms. Further investigation of PYY in the treatment of Barrett's adenocarcinoma is warranted.

Peptide YY attenuates transcription factor activity in tumor necrosis factor-alpha-induced pancreatitis1 1No competing interests declared

BACKGROUND

Acute pancreatitis (AP) is a disease characterized by inflammation. Nuclear factor (NF)-kappaB, Smad proteins, and the steroid hormone family peroxisome proliferator-activated receptors (PPARs) are involved in regulation of gene transcription during the disease process. Peptide YY (PYY), a gastrointestinal hormone, inhibits NF-kappaB translocation to acinar nuclei in tumor necrosis factor (TNF)-alpha-induced AP. We investigated TNF-alpha induction of Smad proteins, PPARalpha/gamma, and NF-kappaB by TNF-alpha, and hypothesized that PYY would attenuate this effect.

STUDY DESIGN

Rat acinar cells were treated with recombinant TNF-alpha (200 ng/mL). PYY (3 to 36) was added at 500 pM at 30 minutes after TNF-alpha treatment until cell harvest at 2 hours. Western blot analysis and intracellular staining of the p65 subunit of NF-kappaB were performed. NF-kappaB, Smad3/4, and PPARalpha/gamma binding activities were determined by protein/DNA array analysis and verified by electrophoretic-mobility shift assay and densitometry.

RESULTS

Cellular localization of NF-kappaB p65 showed nuclear staining within 2 hours, with controls stained in the cytoplasm. With PYY, p65 stained in the cytoplasm. Nuclear p65 was increased significantly (p < 0.05) by TNF-alpha at 2 hours and PYY reduced it. Array analysis revealed upregulation of NF-kappaB, PPARalpha/gamma, and Smad3/4 with TNF-alpha. TNF-alpha stimulated NF-kappaB activation sevenfold, and binding was enhanced (p < 0.05). PYY reduced NF-kappaB binding to control levels. PPAR binding increased 51% after TNF-alpha treatment and was reduced to 33% with PYY. Smad3/4 binding was increased (p < 0.05) above controls with TNF-alpha and PYY reduced it by 40%.

CONCLUSIONS

TNF-alpha increases early nuclear translocation of the p65 subunit of NF-kappaB in acinar cells. Exposure to TNF-alpha activates transcription factors NF-kappaB, Smad3/4, and PPARalpha/gamma. PYY reduces this activation. Treatment with PYY may have therapeutic potential in improving AP.

Antiproliferative and apoptotic effects of rofecoxib on esophageal cancer in vitro1

BACKGROUND

The incidence of Barrett's adenocarcinoma has increased dramatically in the United States, whereas squamous cell carcinoma of the esophagus remains a worldwide problem. Cyclooxygenase (COX)-2 may play an important role in gastrointestinal carcinogenesis and is overexpressed in both Barrett's metaplasia and adenocarcinoma. We hypothesized that a selective and commercially available COX-2 inhibitor, rofecoxib (Vioxx), would inhibit growth of Barrett's adenocarcinoma and squamous cell carcinoma of the esophagus by apoptotic pathways. Additional comparison studies were performed with commercially available COX-2 and COX-1 inhibitors.

MATERIALS AND METHODS

Two esophageal adenocarcinoma cell lines (SEG-1 and BIC) and two esophageal squamous cell cancer lines (KYSE 150 and KYSE 410) were treated with rofecoxib at doses ranging from 8.0 to 125 microg/well. NS-398 (a COX-2 antagonist) and Catechin (a COX-1 antagonist) were also used at doses of 50 and 100 microM. Esophageal cell viability was measured by MTT at 24 and 72 h. Apoptosis was evaluated after 18 h of incubation with rofecoxib, NS398, and Catechin by flow cytometry via annexin V assay.

RESULTS

Rofecoxib, NS-398, and Catechin treatments all resulted in significant antiproliferative effects in both adenocarcinoma and squamous cell carcinoma of the esophagus in vitro. Substantial increases in apoptotic activity were also found in all cell lines.

CONCLUSIONS

Our findings suggest that COX-2 and COX-1 inhibition has potential to become an effective treatment for both histological variants of esophageal cancer. Further in vivo and human studies are warranted to evaluate the safety and clinical utility of these agents in patients with all cancers of the esophagus.