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

 描述(由申请人提供)：黑色素瘤发病率在过去30年中有所增加，在美国有超过80万人以前被诊断为黑色素瘤。黑色素瘤有很高的转移(扩散到身体其他部位)的可能性，占皮肤癌相关死亡的80%。因此，许多黑色素瘤幸存者一直担心他们的癌症何时会复发和扩散。目前，对于黑色素瘤幸存者来说，还没有积极的手段来预防肿瘤的复发和转移。有证据表明，炎症与肿瘤进展和复发等不良临床预后有关。我们发现，人类转移性黑色素瘤细胞表现出一种特殊形式的炎症反应，称为“自身炎症”，因为一个独特的炎症平台被称为“炎症小体”的持续激活。这种自体炎症是由IL-1β介导的，它是一种促炎细胞因子，可以诱导大量的基因组合。EGCG是绿茶中的一种活性成分，具有抗癌、抗炎、抗病原体等多种生物学作用。由于许多被报道被EGCG抑制的炎性介质是由活性的IL-1β(分泌型)控制的，我们推测EGCG可能抑制IL-1β的激活，从而控制其他对肿瘤进展和转移至关重要的介质。我们确实发现，实际和生理上可达到的剂量的EGCG(1微米)抑制具有自体炎症特征的转移性黑色素瘤细胞的IL-1β分泌。我们建议探索实用剂量的EGCG在体外调节人转移性黑色素瘤IL-1β激活的分子机制，并分析EGCG对高倾向于启动肿瘤形成和复发的肿瘤细胞群体的影响。我们还建议利用体内自发转移模型来研究EGCG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(PDX)模型(“阿凡达模型”)，这是人类癌症研究中概括复杂肿瘤微环境的最佳模型之一。我们还将使用转移性黑色素瘤的基因工程小鼠(GEM)模型的细胞。用一种改进的标记方法标记PDX和GEM肿瘤细胞，该方法具有亮度增强、检测灵敏度高、转导效率高和标记稳定的特点。最先进的多模式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。我们将对肿瘤细胞进行检测，以确定EGCG对IL-1β途径、干细胞特性和上皮-间充质转化的影响。由于IL-1β在肿瘤进展中起关键作用，这类研究将阐明EGCG调节癌症细胞因子失调的作用机制，并将导致开发出有效的、无毒性的化学预防药物，癌症幸存者可以服用这些药物来控制肿瘤复发和延长他们的生命。

 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.