Immunomodulatory Mechanisms of Withafarin A in Her-2 neu breast cancer

描述（由申请人提供）：天然植物产品作为抗癌剂新来源的重要性日益明显。使用天然植物衍生产品的好处是它们的低毒性，多模式作用和它们增强免疫系统的潜在能力。随着分析技术的进步，我们可以分析这些化合物的活性成分的活性，这些化合物特异性靶向癌细胞中的生物学途径。Withaferin A（WA）是Withania somnifera（通常称为Ashwagandha）的纯化产品，并作为印度阿育吠陀医学的一部分用于许多土著药物制剂许多世纪。WA已经显示出有效的抗癌特性，并且靶向通过各种途径导致肿瘤细胞凋亡的几种细胞途径。 机制等最近显示它通过抑制HSP 90而增强人胰腺癌细胞的凋亡（Oh等人，2009）以及通过上调人肾癌细胞中的ER应激蛋白（Choi等人，2011年）。此外，已经证明来自亲本植物的粗根和叶提取物通过上调细胞因子如干扰素γ、诱导抗原呈递细胞上的共刺激分子和增加T细胞增殖来刺激1型辅助T细胞（Th 1）免疫（Malik et al.，2009年，Stan等人，2009年）。然而，关于全身施用WA影响肿瘤特异性免疫的机制还没有建立。我们的初步数据表明，WA导致细胞死亡，也诱导免疫刺激蛋白的表达，如热休克蛋白70（HSP 70）的剂量依赖性的方式。HSP 70在肿瘤细胞中的表达通过诱导肿瘤特异性的体液免疫和细胞免疫在免疫系统中起着基础性作用。基于这些结果，我们提出，WA可以刺激免疫介导的癌细胞死亡引发肿瘤特异性反应的主机，通过激活先天免疫细胞，如树突状细胞（DC）和随后的刺激适应性免疫。因此，本研究申请将集中于两个目标：a）WA处理的肿瘤细胞对先天免疫的影响：树突状细胞和巨噬细胞和B）WA在小鼠临床前模型（可移植和Her-2/neu转基因模型）中的肿瘤延迟和存活中的影响，包括WA是否可以特异性靶向Her-2/neu肿瘤特异性免疫。我们的目标是建立并提供证据，证明天然产物如Withaferin A可用作治疗Her-2/neu乳腺癌的化学免疫抑制剂。这种策略的益处将影响常规化疗方案后休眠肿瘤细胞转移的频繁复发，这可能导致肿瘤复发和治疗失败。

DESCRIPTION (provided by applicant): The importance of natural plant products as novel sources of anticancer agents is increasingly becoming evident. The benefit of using natural plant derived products is their low toxicity, multimodal action and their potential ability to enhance the immune system. With the advancement of analytical techniques we can analyze the activity of active components of these compounds that specifically target biological pathways in the cancer cell. Withaferin A (WA) is a purified product of Withania somnifera, (commonly known as Ashwagandha) and is used in many indigenous drug preparations as part of Indian ayurvedic medicine for many centuries. WA has demonstrated potent anti- cancer properties and targets several cellular pathways that result in apoptosis of tumor cells by various mechanisms. Recently it was shown to potentiate apoptosis of human pancreatic cancer cells through inhibition of HSP90 (Oh et al., 2009) as well as through up-regulation of ER stress proteins in human renal carcinoma cells (Choi et al., 2011). Additionally, it was demonstrated that crude root and leaf extracts from the parent plant stimulates T helper Type 1 (Th1) immunity by up-regulation of cytokines such as interferon gamma, induction of co-stimulatory molecules on antigen presenting cells and increased proliferation of T cells (Malik et al., 2009, Stan et al., 2009). However, nothing has been established about the mechanisms by which systemic administration of WA impacts tumor specific immunity. Our preliminary data indicates that WA causes cell death and also induces the expression of immunostimulatory proteins such as heat shock protein 70 (HSP70) in a dose dependent fashion. Expression of HSP70 in the tumor cells plays a fundamental role in the immune system by inducing tumor specific humoral and cellular immunity. Based on these results, we propose that WA can stimulate an immune mediated cancer cell death by eliciting tumor specific response by the host, through activation of innate immune cells such as dendritic cells (DCs) and subsequent stimulation of adaptive immunity. This research application will therefore focus on two goals: a) effect of WA treated tumor cells on innate immunity: dendritic cells and macrophages and b) effect of WA in tumor delay and survival in murine preclinical models (transplantable and Her-2/neu transgenic models) including whether WA can specifically target Her-2/neu tumor specific immunity. Our goal is to establish and provide evidence that natural products such as Withaferin A can be used as a chemoimmunotherapeutic agent in the treatment of Her-2/neu breast cancers. The benefit of such a strategy would impact the frequent recurrence of metastases of dormant tumor cells after conventional chemotherapy regimens that can cause tumor relapse and therapeutic failure.