Introduction. The focus of this study is on early lifestyle factors and their effect on mammary development during puberty and how they relate to increased breast cancer risk and disparities. At this time we do not understand what biological changes occur during pubertal mammary development which leads to a greater risk of developing cancer in later life. Identifying the molecular mechanisms that cause aberrant pubertal mammary development may lead to defined strategies to reduce breast cancer burden in later life. As our bodies use the sugars that we consume for energy they generate waste chemicals known as advanced glycation end products or AGEs for short. Significantly, low income, obesity and a sedentary lifestyle are established factors driving health disparity that also contribute to increased AGE accumulation levels in our bodies. In particular, AGE content in the Western Diet has consistently increased over the last 50 years due to increased consumption of sugar-laden and cheap processed/manufactured foods which are high in reactive AGE metabolites and can promote obesity. Methods. We use a dietary mouse model to assess impact of AGE on normal mammary development. Wild type FVB/n and RAGE null (RAGE-/-) mice are fed the respective diets from weaning until 7 (pubertal) or 12 (adult) weeks of age. Mammary glands are extracted for whole mounting and paraffin embedded for histology. Fibroblasts were isolated from mammary glands and cultured ex vivo. Transwell migration assays were performed with isolated fibroblasts and HC11 mouse mammary epithelial cells. qPCR was performed on the isolated fibroblasts to assess their activation status. Results. Early life exposures during mammary development influence the breast microenvironment to increase breast cancer risk. We show that due to an innate ability to influence the cellular matrix, dietary AGEs disrupt developmental programs during puberty and promote breast tumor growth. Through receptor for AGE (RAGE) dependent and independent mechanisms, chronic AGE consumption delayed ductal extension, increased ductal branching and caused aberrant terminal end bud (TEB) morphology. Dietary AGE activation of RAGE mediated a program of activated stroma leading to hyperplastic growth and the formation of pre-neoplastic lesions which persisted into adulthood. Importantly, AGE mediated effects remained even after diet intervention after puberty. In dietary-AGE breast tumor models, AGE mediated changes in tissue architecture and cell function were recapitulated and resulted in 3-fold increase in neoplastic growth. Through the perpetual activation of a reactive stroma, AGEs derived from diet represent a common early life exposure which can influence tumor behavior. Conclusions. A greater mechanistic understanding of the link between AGE intake during puberty and increased breast cancer risk may define novel potential strategies for lifestyle and pharmacological intervention aimed at reducing breast cancer risk and cancer disparities. Citation Format: Callan C Frye, Bradley A Krisanits, Reid Schuster, Jaime Randise, Lourdes M Nogueira, Kristi Helke, Amanda C LaRue, David P Turner, Victoria J Findlay. Consumption of dietary AGEs during puberty and increased breast cancer risk: A link between lifestyle and cancer disparity [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr C029.

Our research has demonstrated that advanced glycation end products (AGEs) derived from the diet can directly impact neoplastic growth by creating a tumor-enhancing micro-environment. Most people are unaware of what AGEs are or the damage they can cause, but we are exposed to them every day through the lives we lead and the foods that we eat. The Western diet together with more sedentary habits means that lifestyle-associated AGEs are accumulating in our bodies at a faster rate than ever before. Changes in the AGE equilibrium due to lifestyle cause protein dysfunction, reduced genetic fidelity, and aberrant cell signaling activation which we believe contribute to cancer disparity outcomes. Disparity populations defined by AGE-associated risk factors such as diet, smoking, drinking and physical inactivity often bear a greater cancer burden when compared to the general population (reviewed by the PI, Cancer Research 2015). Lifestyle associated AGEs therefore may represent a unifying biological consequence of the social, demographic and environmental risk factors that contribute to the increased cancer incidence and mortality associated with cancer disparity. An important discovery from our work is that consumption of a diet high in AGEs accelerates prostate tumor growth in syngeneic xenograft prostate cancer (PCa) models as well as disease progression in spontaneous PCa models. Critically, dietary-AGE mediated effects on prostate tumor growth were dependent upon the stromal activation of RAGE. An activated stroma is a critical pathway impacting prostate cancer outcomes in African American men. Our studies show that dietary-AGE alters cytokine profiles, increases the activation of cancer associated fibroblasts (CAFs) and increases immune cell recruitment to the tumor microenvironment. Tumor associated immune cells adopt distinct metabolic patterns which function to maintain the energy requirements needed for cell differentiation and functionality. Pathway analysis of expression data from excised tumors shows that AGE consumption significantly impacts energy metabolism through the aberrant expression of MYC regulated transcriptional targets. Our studies also show that AGEs are highest in African American men with prostate cancer. Dietary-AGE mediated activation of tumor stroma therefore may align with the ancestry specific stromal and immune profiles observed in African American men with prostate cancer. Due to their links with lifestyle, both pharmacological and/or interventional strategies aimed at reducing the AGE accumulation pool may be viewed as universal cancer preventive and/or therapeutic initiatives. This may be an attractive option for populations where lifestyle change is not feasible due to poverty, inability, illness, treatment side effects, time, apathy and depression. Citation Format: Bradley Krisanits, Callen Fry, Lourdes M Nogueira, Reid Schuster, Marvella El Ford, Mark T Hamann, Michaell B Lilly, Mahtabuddin Ahmed, Victoria J Findlay, David P Turner. Consumption of lifestyle-associated advanced glycation end products promotes prostate tumor growth by creating a tumor-enhancing stromal microenvironment [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr C083.

Advanced glycation end products, or AGEs, and their corresponding receptor, the receptor for AGE (RAGE), have roles in several chronic diseases such as diabetes and cardiovascular disease due to their proinflammatory properties. Recently AGE: RAGE signaling has been implicated in a number of cancers, including prostate and breast cancer; however, how AGE: RAGE signaling effects these cancers has not been elucidated. To examine this, we have developed a novel dietary AGE tumor model. Our regular and AGE (TestDiet DIO 58G7) diets consist of equal %k/cal from fat, protein, and carbohydrate; however, the predominant source of carbohydrate in the control diet is starch and in the AGE diet is sugar. To generate the high-AGE diet we autoclave at 120°C for 15 min. In the high-AGE diet, the autoclaving mimics the cooking process in foods and induces the formation of AGEs, allowing us to observe the effects of chronic AGE consumption on both normal developmental processes as well as tumor formation and progression. Specifically, we have been able to show the impact of this diet during time periods where the breast is more susceptible to chronic AGE consumption, namely the “windows of susceptibility.” Additionally, we have applied this novel dietary model to the RAGE null (-/-) mice to explore the role of AGE:RAGE signaling further. Specifically, we have shown that chronic consumption of a high-AGE diet disrupts normal pubertal growth in the mammary gland through the recruitment of aberrant stroma, including fibroblasts and macrophages, and that these aberrant changes persist into adulthood. We further show that dietary AGEs promote aggressive tumor growth through manipulation of the tumor microenvironment and that this is RAGE dependent. We propose that this dietary model can be used as an in vivo method to examine the impact of dietary AGEs on the TME and as a mechanism for potential therapeutic and preventative strategies. Citation Format: Reid K. Schuster, Bradley A. Krisanits, Jamie Randise, Lourdes M. Nogueira, Kristi Helke, Amanda C. LaRue, David P. Turner, Victoria J. Findlay. A novel dietary advanced glycation end product (AGE) model to assess impact on tumor progression [abstract]. In: Proceedings of the AACR Special Conference on the Evolving Landscape of Cancer Modeling; 2020 Mar 2-5; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2020;80(11 Suppl):Abstract nr B26.