scholarly journals Enriched environment inhibits breast cancer progression in obese models with intact leptin signaling

2019 ◽  
Vol 26 (5) ◽  
pp. 483-495 ◽  
Author(s):  
Grant D Foglesong ◽  
Nicholas J Queen ◽  
Wei Huang ◽  
Kyle J Widstrom ◽  
Lei Cao
Keyword(s):  
Breast Cancer ◽  
Tumor Growth ◽  
Cancer Progression ◽  
Environmental Enrichment ◽  
Tumor Growth Rate ◽  
Breast Tumorigenesis ◽  
Leptin Signaling ◽  
Global Epidemic ◽  
Diet Induced Obesity ◽  
Mammary Tumor Growth

Obesity is becoming a global epidemic and is a risk factor for breast cancer. Environmental enrichment (EE), a model recapitulating an active lifestyle, leads to leanness, resistance to diet-induced obesity (DIO) and cancer. One mechanism is the activation of the hypothalamic–sympathoneural–adipocyte (HSA) axis. This results in the release of norepinephrine onto adipose tissue inducing a drop of leptin. This study aimed to test the effects of EE on breast cancer onset and progression while considering the effect of leptin by utilizing the transgenic MMTV-PyMT model as well as several models of varied leptin signaling. EE was highly effective at reducing weight gain, regardless of the presence of leptin. However, the effects of EE on tumor progression were dependent on leptin signaling. EE decreased leptin and reduced mammary tumor growth rate in MMTV-PyMT spontaneous and DIO transplantation models; in contrast, the absence of leptin in ob/ob mice resulted in increased tumor growth likely due to elevated norepinephrine levels. Our results suggest that the microenvironment is critical in breast tumorigenesis and that the drop in leptin is an important peripheral mediator of the EE anti-breast cancer effects, offsetting the potential pro-tumorigenic effects of norepinephrine responding to a complex environment.

scholarly journals Calorie restriction and rapamycin inhibit MMTV-Wnt-1 mammary tumor growth in a mouse model of postmenopausal obesity

2011 ◽  
Vol 19 (1) ◽  
pp. 57-68 ◽  
Author(s):  
Leticia M Nogueira ◽  
Sarah M Dunlap ◽  
Nikki A Ford ◽  
Stephen D Hursting
Keyword(s):  
Breast Cancer ◽  
Energy Balance ◽  
Tumor Growth ◽  
Cancer Progression ◽  
Calorie Restriction ◽  
Mammary Tumor ◽  
Treadmill Exercise ◽  
Mammary Tumor Growth ◽  
Postmenopausal Obesity ◽  
Ad Libitum

Obesity is an established risk and progression factor for postmenopausal breast cancer. Interventions to decrease caloric intake and/or increase energy expenditure beneficially impact tumor progression in normoweight humans and animal models. However, despite the increasingly high global prevalence of obesity, the effects and underlying mechanisms of these energy balance modulating interventions are poorly characterized in obese individuals. The goal of this study was to better characterize the mechanism(s) responsible for the link between energy balance and breast cancer progression in the postmenopausal obesity context. We compared the effects of calorie restriction (CR), treadmill exercise (EX), and mammalian target of rapamycin (mTOR inhibitor) treatment on body composition, serum biomarkers, cellular signaling, and mammary tumor growth in obese mice. Ovariectomized C57BL/6 mice were administered a diet-induced obesity regimen for 8 weeks, then randomized into three treatment groups: control (semipurified diet fedad libitum, maintained the obese state); 30% CR (isonutrient relative to control except 30% reduction in carbohydrate calories); and EX (control diet fedad libitumplus treadmill exercise). Mice were implanted with syngeneic MMTV-Wnt-1 mammary tumor cells at week 12. Rapamycin treatment (5 mg/kg every 48 h) started at week 14. Tumors were excised at week 18. CR and rapamycin (but not EX) significantly reduced final tumor weight compared to control. In follow-up analysis, constitutive activation of mTOR ablated the inhibitory effects of CR on Wnt-1 mammary tumor growth. We conclude that mTOR inhibition may be a pharmacologic strategy to mimic the anticancer effects of CR and break the obesity–breast cancer progression link.

scholarly journals Investigating New Therapeutic Strategies Targeting Hyperinsulinemia's Mitogenic Effects in a Female Mouse Breast Cancer Model

Endocrinology ◽  
2013 ◽  
Vol 154 (5) ◽  
pp. 1701-1710 ◽  
Author(s):  
Ran Rostoker ◽  
Keren Bitton-Worms ◽  
Avishay Caspi ◽  
Zila Shen-Orr ◽  
Derek LeRoith
Keyword(s):  
Breast Cancer ◽  
Tumor Growth ◽  
Breast Tumor ◽  
Experimental Studies ◽  
Tumor Development ◽  
Treated Group ◽  
Tumor Growth Rate ◽  
Breast Cancer Patients ◽  
Mitogenic Effect

Abstract Epidemiological and experimental studies have identified hyperinsulinemia as an important risk factor for breast cancer induction and for the poor prognosis in breast cancer patients with obesity and type 2 diabetes. Recently it was demonstrated that both the insulin receptor (IR) and the IGF-IR mediate hyperinsulinemia's mitogenic effect in several breast cancer models. Although IGF-IR has been intensively investigated, and anti-IGF-IR therapies are now in advanced clinical trials, the role of the IR in mediating hyperinsulinemia's mitogenic effect remains to be clarified. Here we aimed to explore the potential of IR inhibition compared to dual IR/IGF-IR blockade on breast tumor growth. To initiate breast tumors, we inoculated the mammary carcinoma Mvt-1 cell line into the inguinal mammary fat pad of the hyperinsulinemic MKR female mice, and to study the role of IR, we treated the mice bearing tumors with the recently reported high-affinity IR antagonist-S961, in addition to the well-documented IGF-IR inhibitor picropodophyllin (PPP). Although reducing IR activation, with resultant severe hyperglycemia and hyperinsulinemia, S961-treated mice had significantly larger tumors compared to the vehicle-treated group. This effect maybe secondary to the severe hyperinsulinemia mediated via the IGF-1 receptor. In contrast, PPP by partially inhibiting both IR and IGF-IR activity reduced tumor growth rate with only mild metabolic consequences. We conclude that targeting (even partially) both IR and IGF-IRs impairs hyperinsulinemia's effects in breast tumor development while simultaneously sparing the metabolic abnormalities observed when targeting IR alone with virtual complete inhibition.

scholarly journals Increased Tumor Growth in Mice with Diet-Induced Obesity: Impact of Ovarian Hormones

Endocrinology ◽  
2006 ◽  
Vol 147 (12) ◽  
pp. 5826-5834 ◽  
Author(s):  
Shoshana Yakar ◽  
Nomeli P. Nunez ◽  
Patricia Pennisi ◽  
Pnina Brodt ◽  
Hui Sun ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Tumor Growth ◽  
Glucose Intolerance ◽  
Tumor Development ◽  
Tumor Growth Rate ◽  
Obese Mice ◽  
Female Mice ◽  
Diet Induced Obesity ◽  
Body Adiposity ◽  
Obese Female

Obesity increases the risk of many cancers in both males and females. This study describes a link between obesity, obesity-associated metabolic alterations, and the risk of developing cancer in male and female mice. The goal of this study was to evaluate the relationship between gender and obesity and to determine the role of estrogen status in obese females and its effect on tumor growth. We examined the susceptibility of C57BL/6 mice to diet-induced obesity, insulin resistance/glucose intolerance, and tumors. Mice were injected sc with one of two tumorigenic cell lines, Lewis lung carcinoma, or mouse colon 38-adenocarcinoma. Results show that tumor growth rate was increased in obese mice vs. control mice irrespective of the tumor cell type. To investigate the effect of estrogen status on tumor development in obese females, we compared metabolic parameters and tumor growth in ovariectomized (ovx) and intact obese female mice. Obese ovx female mice developed insulin resistance and glucose intolerance similar to that observed in obese males. Our results demonstrate that body adiposity increased in ovx females irrespective of the diet administered and that tumor growth correlated positively with body adiposity. Overall, these data point to more rapid tumor growth in obese mice and suggest that endogenous sex steroids, together with diet, affect adiposity, insulin sensitivity, and tumor growth in female mice.

The cholesterol metabolite 27-hydroxycholesterol increases the secretion of extracellular vesicles which promote breast cancer progression

Endocrinology ◽  
2021 ◽  
Author(s):  
Amy E Baek ◽  
Natalia Krawczynska ◽  
Anasuya Das Gupta ◽  
Svyatoslav Victorovich Dvoretskiy ◽  
Sixian You ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Growth ◽  
Cancer Cells ◽  
Extracellular Vesicles ◽  
Cancer Progression ◽  
Myeloid Cells ◽  
Breast Cancer Progression ◽  
Label Free ◽  
Tumor Growth And Metastasis ◽  
Promote Breast Cancer

Abstract Cholesterol has been implicated in the clinical progression of breast cancer, a disease that continues to be the most commonly diagnosed cancer in women. Previous work has identified the cholesterol metabolite, 27-hydroxycholesterol (27HC), as a major mediator of the effects of cholesterol on breast tumor growth and progression. 27HC can act as an estrogen receptor (ER) modulator to promote the growth of ERα+ tumors, and a liver x receptor (LXR) ligand in myeloid immune cells to establish an immune-suppressive program. In fact, the metastatic properties of 27HC require the presence of myeloid cells, with neutrophils (PMNs) being essential for the increase in lung metastasis in murine models. In an effort to further elucidate the mechanisms by which 27HC alters breast cancer progression, we made the striking finding that 27HC promoted the secretion of extracellular vesicles (EVs), a diverse assortment of membrane bound particles that include exosomes. The resulting EVs had a size distribution that was skewed slightly larger, compared to EVs generated by treating cells with vehicle. The increase in EV secretion and size was consistent across three different subtypes: primary murine PMNs, RAW264.7 monocytic cells and 4T1 murine mammary cancer cells. Label-free analysis of 27HC-EVs indicated that they had a different metabolite composition to those from vehicle-treated cells. Importantly, 27HC-EVs from primary PMNs promoted tumor growth and metastasis in two different syngeneic models, demonstrating the potential role of 27HC induced EVs in the progression of breast cancer. EVs from PMNs were taken up by cancer cells, macrophages and PMNs, but not T cells. Since EVs did not alter proliferation of cancer cells, it is likely that their pro-tumor effects are mediated through interactions with myeloid cells. Interestingly, RNA-seq analysis of tumors from 27HC-EV treated mice do not display significantly altered transcriptomes, suggesting that the effects of 27HC-EVs occur early on in tumor establishment and growth. Future work will be required to elucidate the mechanisms by which 27HC increases EV secretion, and how these EVs promote breast cancer progression. Collectively however, our data indicate that EV secretion and content can be regulated by a cholesterol metabolite, which may have detrimental effects in terms of disease progression, important findings given the prevalence of both breast cancer and hypercholesterolemia.

scholarly journals LINC00665 promotes breast cancer progression through regulation of the miR-379-5p/LIN28B axis

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Wei Ji ◽  
Yu-Ling Diao ◽  
Yi-Ran Qiu ◽  
Jie Ge ◽  
Xu-Chen Cao ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Progression ◽  
Epithelial Mesenchymal Transition ◽  
Normal Breast ◽  
Breast Cancer Progression ◽  
Migration And Invasion ◽  
Breast Tumorigenesis ◽  
Mesenchymal Transition ◽  
Tumorigenesis And Progression ◽  
Mirna Sponges

AbstractBreast cancer is the most common malignant tumor among women worldwide. Although increasing evidence indicates that long noncoding RNAs (lncRNAs) play critical roles during breast tumorigenesis and progression, the involvement of most lncRNAs in breast cancer remains largely unknown. In the current study, we demonstrated that LINC00665 promotes breast cancer cell proliferation, migration, and invasion. Accumulating evidence indicates that many lncRNAs can function as endogenous miRNA sponges by competitively binding common miRNAs. In this study, we demonstrated that LINC00665 functions as a sponge for miR-379-5p, reducing the ability of miR-379-5p to repress LIN28B. LINC00665 promoted breast cancer progression and induced an epithelial–mesenchymal transition-like phenotype via the upregulation of LIN28B expression. Clinically, LINC00665 expression was increased but miR-379-5p expression was decreased in breast cancer tissues compared with that in normal breast tissues in the TCGA database. Furthermore, the expression of LINC00665 was negatively related with miR-379-5p expression. Collectively, our results reveal the LINC00665–miR-379-5p–LIN28B axis and shed light on breast cancer therapy.

Sign in / Sign up

Export Citation Format

Share Document