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.

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.

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), < 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<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<0.05). Triple-negative breast cancer patients who developed brain and lung metastases were younger <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 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.
 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.
 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 (<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.
 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.

Vitamin E and the Y4 agonist BA-129 decrease prostate cancer growth and production of vascular endothelial growth factor

BACKGROUND

A biologically active form of vitamin E, alpha-tocopherol succinate (ATS), has been shown to induce apoptosis of hormone-refractory prostate cancer in vitro and inhibit cell growth in vivo. The gastrointestinal hormone peptide YY (PYY) has growth inhibitory activity against multiple cancer cell lines and is synergistic with ATS against breast and pancreatic cancer growth. BA-129, a specific Y4 receptor agonist, has growth inhibitory effects on pancreatic cancer in vitro. We investigated the effects of BA-129 and ATS on prostate cancer growth and evaluated their effects on vascular endothelial growth factor (VEGF) production.

METHODS

A hormone-refractory human prostate cancer cell line, PC-3, was treated with ATS alone at 10 pg/ml, PYY or BA-129 alone at doses of 75 and 500 pmol/ml, or a combination of the two agents. Cell growth was measured by MTT assay and hemocytometry using trypan blue. Quantitative measurement of VEGF was performed by ELISA. Statistical analysis was achieved by ANOVA.

RESULTS

ATS exhibited significant (P < 0.05) growth inhibitory effects in prostate cancer cells. PYY also inhibited growth (P < 0.05). ATS treatment reduced VEGF production (P < 0.05). PYY treatment increased VEGF. When ATS was given in combination with BA-129, VEGF production was further reduced (P < 0.05).

CONCLUSIONS

Both PYY and ATS inhibit growth in hormone-refractory prostate cancer, with augmentation when used in combination. VEGF production is inhibited by vitamin E, but increased by PYY. ATS abolishes the augmented VEGF response to PYY. Our data suggest that PYY is involved in the regulation of VEGF production and prostate cancer growth.

Effect of creatine monohydrate on cardiac function in a rat model of endotoxemia

BACKGROUND

Reports have attributed cardiac failure during acute models of endotoxemia to a lack of high-energy phosphates. This study was undertaken to investigate whether creatine (Cr) administered during perfusion could enhance myocardial protection and improve recovery of cardiac function in a rat model of endotoxemia.

METHODS

Acute endotoxemia was induced in rats by a bolus injection of Escherichia coli endotoxin (LPS: 4 mg/kg, ip) while control rats were injected with an equal volume of 0.9% normal saline. To assess the adequacy of energy metabolism, freeze-clamped hearts were obtained from animals to study the concentrations of endogenous ATP, phosphocreatine (PCr), inorganic phosphate (P(i)), and intracellular pH by (31)P-cryomagnetic resonance spectroscopy. In a separate experiment, isolated hearts were perfused via a Langendorff column with Krebs-Henseleit buffer containing different concentrations of creatine monohydrate (1, 3, or 10 mM). Cardiac performance was evaluated via a paced (300 bpm) isovolumetric balloon preparation. Measurements of cardiac function including left ventricular developed pressure (LVDP), the maximum rates of ventricular pressure rise (LV +dP/dt) and fall (LV -dP/dt), and coronary flow were made for both LPS and saline-treated animals.

RESULTS

High-energy phosphate ratios of PCr/ATP and PCr/P(i) in hearts declined significantly at 4 h after endotoxin treatment. As anticipated, LVDP and LV +dP/dt(max) at a given preload and heart rate were significantly (P < 0.05) lower at 4 h when measured at the same time point. The functional recovery of these parameters was not improved by the addition of creatine monohydrate to the perfusion buffer. Creatine produced a significant (P < 0.05) negative inotropic effect in hearts from saline-treated animals. The LVDP was reduced by 30% at the lowest concentration and by 50% at the highest concentration of creatine monohydrate. Furthermore, creatine significantly (P < 0.05) reduced LV -dP/dt(max) in both saline and LPS-treated rats. These data demonstrate that exogenous creatine does not contribute to myocardial preservation in endotoxemia.

CONCLUSIONS

Energy stores in the rat heart decline early in endotoxemia accompanied by reduced myocardial performance, suggesting that the ability of the heart to perform mechanical work is impaired. Cardiac dysfunction in an acute model of endotoxemia was not improved with exogenous creatine during perfusion. Creatine's effects were primarily lusitropic by delaying the onset of myocardial relaxation in all hearts. The deleterious effects of exogenous creatine monohydrate in normal hearts should be examined in future experimental studies.