New Approaches to Prevent or Treat Breast Cancer Metastases

描述(由申请人提供)： 在确诊为乳腺癌的女性中，约40%会进展为转移性疾病。然而，转移瘤不能通过手术或放疗去除，而且大多数转移瘤对化疗耐药。因此，专门预防或消除转移的治疗方法在结果中提供了很大的希望。最近的研究表明，通过接种疫苗来增强对乳腺肿瘤的特异性辅助性或细胞毒性T淋巴细胞(CTL)反应，可能会导致特异性地消除微转移。然而，疫苗诱导的免疫和临床反应不佳，突显了改进疫苗策略的必要性。本研究利用临床前转移的小鼠乳腺肿瘤模型4T1，通过联合接种IL-6抑制剂姜黄素来提高转移性乳腺癌的疫苗治疗效果。我们以前证明，MAGE-b DNA疫苗在这个模型中提供了对乳腺癌转移的显著保护，尽管不是完全的。白介素6可能是疫苗效力下降的原因之一。它在4T1原发肿瘤和转移瘤中高度上调，可能是通过核因子KappaB(NFkB)，是体内树突状细胞(DC)分化的有效调节因子。IL-6可激活未成熟树突状细胞转导和转录激活因子(STAT)3的表达，阻止未成熟树突状细胞成熟并向T细胞递呈抗原。这可能会导致T细胞无反应。能够抑制IL-6的药物可能会增强疫苗的效力。姜黄素可能就是这样一种药物，因为它抑制IL-6的产生。MAGE-b和IL-6在人类乳腺癌中经常被检测到，这使得4T1模型具有临床意义。这项提议的长期目标是在4T1模型中开发一种新的无毒的MAGE-b疫苗接种和姜黄素联合疗法，如果成功，重点是将其转化为人类临床试验。假设是姜黄素改善了MAGE-b DNA疫苗接种后T细胞的激活和随后的免疫反应，从而进一步降低了乳腺癌转移的频率。具体目的如下：(1)检测MAGE-b疫苗加和不加姜黄素对肿瘤和转移瘤的影响。为此，将用MAGE-b DNA疫苗预防性或治疗性地免疫小鼠，并用4T1肿瘤细胞攻击。一旦可以感觉到原发肿瘤，就会每天服用姜黄素。将确定转移频率、肿瘤大小和生存时间；(2)测试姜黄素对疫苗和肿瘤诱导的免疫反应以及对肿瘤细胞增殖和凋亡的直接作用(S)。为此，将分析治疗和对照小鼠的脾、淋巴结、肿瘤和转移是否存在激活的CD4和CD8T细胞、调节性T细胞和成熟的DC。此外，还将分析治疗和对照小鼠的肿瘤和转移瘤中NFkB和NFkB调节的基因的表达，这些基因直接参与免疫反应，如IL-6、TNF1和STAT3，以及增殖和凋亡。与公共卫生相关：目前的癌症治疗对转移没有效果。在这项研究提案中，将利用反映人类转移性乳腺癌的临床前小鼠模型，开发一种新的无毒的MAGE-b疫苗接种和姜黄素联合疗法，对乳腺癌转移有效。

DESCRIPTION (provided by applicant): About 40% of the women diagnosed with breast cancer will progress to metastatic disease. However, metastases cannot be removed by surgery or radiation, and most metastases are chemoresistant. Therefore, therapies that specifically prevent or eliminate metastases offer great promise in the outcome. Recent studies indicate that enhancement of specific helper or cytotoxic T lymphocyte (CTL) responses to breast tumors through vaccination could potentially lead to the specific elimination of micro-metastases. However, poor vaccine-induced immune and clinical responses underscore the need for improved vaccine strategies. This research proposal is focused on the improvement of vaccine therapy against metastatic breast cancer by combining vaccination with the IL-6 inhibitor curcumin, using the preclinical metastatic mouse breast tumor model 4T1. We previously demonstrated that Mage-b DNA vaccination provides significant protection against breast cancer metastases in this model, albeit not completely. Interleukin (IL)-6 may contribute to decreased vaccine efficacy. It is highly up regulated in the 4T1 primary tumors and metastases, probably via the Nuclear Factor Kappa B (NFkB), and is a potent regulator of dendritic cells (DC) differentiation in vivo. IL-6 activates the expression of transducer and activator of transcription (STAT)3 in immature DC, preventing the DC from maturation and subsequent presentation of antigens to T cells. This may lead to T cell unresponsiveness. Agents that are able to inhibit IL-6 may lead to enhanced vaccine efficacy. Curcumin could be such an agent, since it inhibits IL-6 production. Both Mage-b and IL-6 are frequently detected in human breast cancer, which makes the 4T1 model clinically relevant. The long-term objective of this proposal is to develop a novel non- toxic combination therapy of Mage-b vaccination and curcumin in the 4T1 model, with a focus on its translation into human clinical trials, if successful. The hypothesis is that curcumin improves T cell activation and subsequent immune responses upon Mage-b DNA vaccination, resulting in further reduction of the frequency of breast cancer metastases. The specific aims are as follows:(1) Testing the effect of Mage-b vaccination with and without curcumin on tumors and metastases. For this purpose, mice will be immunized preventively or therapeutically with Mage-b DNA vaccine and challenged with 4T1 tumor cells. As soon as the primary tumor can be felt curcumin will be administered daily. Frequency of metastases, tumor size, and survival times will be determined; (2) Testing the direct effect(s) of curcumin on vaccine- and tumor-induced immune responses, and on proliferation and apoptosis of tumor cells. For this purpose, spleen, lymph nodes, tumors and metastases of treated and control mice will be analyzed for the presence of activated CD4 and CD8 T cells, regulatory T cells and mature DC. In addition, tumors and metastases of treated and control mice will also be analyzed for the expression of NFkB and NFkB-regulated genes that are directly involved in immune responses such as IL-6, TNF1, and STAT3, and for proliferation and apoptosis. PUBLIC HEALTH RELEVANCE: Current treatment of cancer is ineffective against metastases. In this research proposal a novel non-toxic combination therapy of Mage-b vaccination and curcumin will be developed that is effective against breast cancer metastases, using a preclinical mouse model that reflects metastatic breast cancer in humans.