Induction of a tumor-hostile breast cancer microenvironment by metformin

 描述（由申请人提供）：关于乳腺癌化学预防，已经开发出很少的药物来破坏维持肿瘤支持性微环境的自分泌/旁分泌信号传导回路。通过 PGE2（前列腺素 E2）和促炎细胞因子的慢性炎症信号通过促进癌细胞增殖而在介导肿瘤进展中发挥重要作用。抗糖尿病药物二甲双胍与降低乳腺癌发病率有关，在实验模型中表现出抗增殖、抗炎作用。然而，很少有研究调查二甲双胍暴露是否可以减弱肿瘤促进的自分泌/旁分泌炎症信号，这些信号调节乳腺癌微环境。本研究的目标是确定二甲双胍调节的炎症信号在肿瘤微环境中的影响，从而对肿瘤进展产生影响。 PGE2、膜联蛋白 A2 以及生长和分化因子 15 (GDF15) 都是在癌症和炎症的细胞外源信号传导中发挥独特作用的分子。因此，总体假设是二甲双胍通过破坏 PGE2/膜联蛋白 A2/GDF15 信号轴来破坏乳腺癌中的促肿瘤自分泌/旁分泌炎症信号。因此，本研究的具体目标包括： 目标 1 将检验二甲双胍调节导致 BCC 细胞内在和细胞外在抑制的假设 体外和体内的增殖和侵袭性。目标 2 将检验二甲双胍通过抑制 PGE2 和膜联蛋白 A2 的产生以及诱导 GDF15 表达来调节乳腺癌微环境中肿瘤支持性炎症信号传导的假设。这些研究的长期目标将通过识别抗肿瘤作用中涉及的关键信号元件，促进二甲双胍和类似“代谢修复药物”作为治疗/化学预防药物的开发。更重要的是，这些研究将为肿瘤疾病中代谢和炎症的交叉提供有价值的见解。

 DESCRIPTION (provided by applicant): With regard to breast cancer chemoprevention, few drugs have been developed to disrupt the autocrine/paracrine signaling circuits which maintain the tumor-supportive microenvironment. Chronic inflammatory signaling through PGE2 (prostaglandin E2) and proinflammatory cytokines play significant roles in mediating tumor progression by promoting cancer cell proliferation. The anti-diabetic drug metformin is associated with decreased incidence of breast cancer, exhibits anti-proliferative, anti-inflammatory, effects in experimental models. However, there are few studies investigating if metformin exposure can attenuate tumor promoting autocrine/paracrine inflammatory signals which condition the breast cancer microenvironment. For this study, the goal is to ascertain the impact of metformin-modulated inflammatory signaling in the tumor microenvironment and consequently on tumor progression. PGE2, Annexin A2, and growth and Differentiation Factor 15(GDF15) are each molecules which play a distinct role in cell-extrinsic signaling in cancer and inflammation. As such, the overall hypothesis is that metformin disrupts pro-neoplastic autocrine/paracrine inflammatory signaling in breast cancer by disrupting the PGE2/annexin A2/GDF15 signaling axis. As such, the specific aims of this study include: Aim 1 will test the hypothesis that metformin-conditioning leads to cell intrinsic and cell extrinsic inhibition of BCC proliferation and invasiveness in vitro and in vivo. Aim 2 will test the hypothesis that metformin modulates tumor-supportive inflammatory signaling in breast cancer microenvironment by repressing PGE2 and annexin A2 production, and by inducing of GDF15 expression. The long term goal of these studies will contribute to the development of metformin and similar "metabolic reconditioning drugs" as therapeutic/chemo-preventive agents by identifying the key signaling elements involved in their antineoplastic effects. More fundamentally, these studies will provide valuable insight into the intersection of metabolism and inflammation in neoplastic disease.