Modulation of Inflammasome-mediated cytokine activation by EGCG in human melanoma

 描述（由申请人提供）：黑色素瘤的发病率在过去30年中有所增加，在美国有超过800，000人先前诊断为黑色素瘤。黑色素瘤有很高的可能性转移（扩散到身体的其他部位），占皮肤癌相关死亡的80%。因此，许多黑色素瘤幸存者总是担心他们的癌症可能会复发和扩散。目前，对于黑色素瘤幸存者，没有积极的手段来预防肿瘤复发和转移。证据强烈表明，炎症与不利的临床预后相关，如肿瘤进展和复发。我们已经发现，人转移性黑色素瘤细胞显示出一种称为“自身炎症”的特殊形式的炎症反应，这是因为一种称为“炎性体”的独特炎症平台的持续激活。这种自身炎症由IL-1β介导，IL-1 β是一种诱导大量基因组合的促炎细胞因子。表没食子儿茶素没食子酸酯是绿色茶中的活性成分，具有多种生物学作用，包括抗癌、抗炎和抗病原体特性。由于许多被EGCG抑制的炎症介质是由活性IL-1β（分泌形式）控制的，我们假设EGCG可能抑制IL-1β的活化，从而控制其他对肿瘤进展和转移重要的介质。我们确实发现，一个实际的和生理上可实现的剂量的EGCG（1 μM）抑制IL-1β分泌的人转移性黑色素瘤细胞携带的自体炎症的特征。我们建议探索实际剂量的EGCG在体外调节人转移性黑色素瘤中IL-1β活化的分子作用机制，并分析EGCG对肿瘤细胞群[推定的癌症干细胞（CSC）群]的影响，该肿瘤细胞群具有启动肿瘤形成和复发的高趋势。我们还建议使用体内自发转移模型研究表没食子儿茶素没食子酸酯对黑色素瘤复发的生物学作用。我们将使用患者来源的肿瘤异种移植物（PDX）模型（“化身模型”），这是人类癌症研究中最好的模型之一，它重现了复杂的肿瘤微环境。我们还将使用来自转移性黑色素瘤的基因工程小鼠（GEM）模型的细胞。PDX和GEM肿瘤细胞将用改进的标记方法标记，具有增强的亮度、高检测灵敏度、高转导效率和稳定的标记。最先进的多模态成像将用于纵向监测初始肿瘤部位、淋巴结和远处转移部位的肿瘤复发。将检查肿瘤细胞以确定EGCG对IL-1β通路、CSC性状和上皮-间充质转化的影响。由于IL-1β在肿瘤进展中起着关键作用，因此这些研究将阐明EGCG在调节癌症中失调的细胞因子方面的作用机制，并将导致开发有效的化学预防剂，其毒性有限或无毒性，可由癌症幸存者服用以控制肿瘤复发并延长其生命。

 DESCRIPTION (provided by applicant): Melanoma incidence has increased in the last 30 years and over 800,000 people have a previous diagnosis of melanoma in the US. Melanoma has a high likelihood to metastasize (spread to other parts of the body) and accounts for 80% of the skin cancer-related deaths. As a result, many melanoma survivors constantly fear when their cancers might come back and spread. Currently, there is no active means to prevent tumor recurrence and metastasis for melanoma survivors. Evidence strongly suggests that inflammation is associated with unfavorable clinical prognosis such as tumor progression and recurrence. We have found that human metastatic melanoma cells show a special form of inflammatory response called "autoinflammation" because of constant activation of a unique inflammatory platform called "inflammasome". This autoinflammation is mediated by IL-1β, a pro-inflammatory cytokine inducing a large portfolio of genes. EGCG is an active ingredient in green tea and has many biological effects including anti-cancer, anti-inflammatory, and anti-pathogen properties. Because many inflammatory mediators reported to be inhibited by EGCG are controlled by active IL-1β (secreted form), we hypothesized that EGCG might inhibit IL-1β activation, thereby controlling other mediators that are important for tumor progression and metastasis. We indeed found that a practical and physiologically achievable dose of EGCG (1 µM) suppresses IL-1β secretion in human metastatic melanoma cells that carry a feature of autoinflammation. We propose to explore the molecular mechanisms of action of a practical dose of EGCG in regulating IL-1β activation in human metastatic melanoma in vitro, and analyze the effects of EGCG on a tumor cell population [putative cancer stem cell (CSC) population] that has a high tendency to initiate tumor formation and recurrence. We also propose to study the biological effects of EGCG on melanoma recurrence using a spontaneous metastasis model in vivo. We will use patient-derived tumor xenograft (PDX) model ("avatar model"), one of the best models in human cancer research that recapitulates complex tumor microenvironment. We will also use cells from a genetically engineered mouse (GEM) model of metastasizing melanoma. PDX and GEM tumor cells will be labeled with a modified labeling method with enhanced brightness, high detection sensitivity, high transduction efficiency and stable labeling. State-of-the-art multimodality imaging will be used to longitudinally monitor tumor recurrence at the initial tumor site, lymph nodes and distant metastatic sites. Tumor cells will be examined to define the effects of EGCG on IL-1β pathway, CSC traits, and epithelial-mesenchymal transition. Because IL-1β plays a critical role in tumor progression, such studies will elucidate the mechanisms of action of EGCG on regulating dysregulated cytokines in cancers and will lead to the development of effective chemopreventive agents with limited to no toxicity that can be taken by cancer survivors to control tumor recurrence and prolong their lives.