Mechanisms of Cancer Initiation by TRIM32

项目总结 Trim32是一种E3-泛素连接酶，是支架蛋白家族的成员，与癌症和 人的发展。我们通过致癌将Trim32的激活与癌症联系起来 在小鼠角质形成细胞模型中的研究，并初步证实了这种关联在人类鳞状细胞中的存在 细胞癌(SCC)。我们已经确定Piasy是Trim32靶向降解的底物蛋白 泛素化，为Piasy如何在细胞中受到调控提供了第一个证据。其他人已经证实 PIASY是一种促凋亡的E3-SUMO连接酶，参与肿瘤抑制因子P53和NFkB细胞的调控 生存之路。Piasy在癌症中的作用是显而易见的，因为它是高危HPV-E6灭活的靶标 与人宫颈癌有关的蛋白质，其下调是预测从 骨髓增生异常综合征(MDS)到晚期和慢性粒细胞白血病(CML)。Piasy是一名职业选手- 凋亡因子，诱导慢性粒细胞白血病细胞、人成纤维细胞和小鼠角质形成细胞的凋亡。我们证明了 TRIM32对UVB诱导的角质形成细胞凋亡有保护作用，并与TNFa有协同作用。此外，我们发现一个 人鳞状细胞癌中Piasy和Trim32表达水平的负相关这些数据表明， Trim32激活和PIASY降解在上皮癌变和肿瘤进展中的作用我们 建议定义Trim32/Piasy在细胞内信号、癌变和人类鳞癌中的相互作用 根据以下目的：1)通过Trim32确定Piasy亚细胞定位的动态调节 E3连接酶支架蛋白及其在表皮角质形成细胞存活途径中的作用 检测Trim32和Piasy在角质形成细胞的启动、促进和恶性进展中的作用 3)探讨Trim32/Piasy状态在人皮肤和头部的预测价值。 颈部鳞状细胞癌预后作为未来Trim32/Piasy相互作用或分子靶向策略的基础 癌症中的下游效应器。Trim32和Piasy Beyond上皮细胞的表达，如在血液系统， 两个人类遗传性疾病患者肌肉和神经组织与Trim32失活突变的存在 这些症状意味着理解Trim32和Piasy在人类疾病中的调控具有更广泛的意义。项目叙事 Trim32和Piasy：两种在癌症发生中起相反作用的酶 Trim32是一种支架蛋白，它控制着必须相互作用的其他蛋白质的时间和位置 适当地导致正常的组织发育，如果不正常，可能会导致癌症。我们有 研究表明，Trim32增加了一个小分子泛素并破坏了Piasy(一种需要 重要基因调控因子P53、NFB、STAT和STAT介导的肿瘤抑制和细胞存活 Smad/TGFbeta)，为Piasy如何在细胞中受到调控提供了第一个证据。了解如何将 癌症中可检测到的最早变化，如Trim32激活，延长了异常细胞的存活时间 并促进进一步的变化(癌症基因的激活和肿瘤抑制基因的失活) 为新的选择性、低毒的皮肤分子靶向预防和治疗提供了基础 癌症，也可能来自表达Trim32和Piasy的其他组织的癌症，例如 慢性粒细胞白血病、肌肉和脑肿瘤。

PROJECT SUMMARY Trim32 is an E3-ubiquitin ligase and a member of a family of scaffold proteins involved in both cancer and human development. We made the novel association of Trim32 activation with cancer through carcinogenesis studies in mouse keratinocyte models and have preliminarily confirmed this association in human squamous cell carcinoma (SCC). We have identified Piasy as a substrate protein targeted for degradation by Trim32 ubiquitylation, providing the first evidence for how Piasy is regulated in cells. Others have established that Piasy is a pro-apoptotic E3-SUMO ligase involved in regulation of tumor suppressor p53 and of NFkB cellular survival pathways. Piasy's role in cancer is evident as it is targeted for inactivation by the high-risk HPV-E6 protein implicated in human cervical carcinoma, and its downregulation is prognostic for conversion from myelodysplastic syndrome (MDS) to later stages and chronic myeloid leukemia (CML). Piasy is a pro- apoptotic factor, inducing apoptosis in CML cells, human fibroblasts and mouse keratinocytes. We show that Trim32 protects keratinocytes from apoptosis induced by UVB and synergized by TNFa. Moreover, we find an inverse correlation between Piasy and Trim32 expression levels in human SCC. These data suggest a direct role of Trim32 activation and Piasy degradation in epithelial carcinogenesis and tumor progression. We propose to define Trim32/Piasy interactions in intracellular signaling, carcinogenesis and human SCC according to the following aims: 1) define the dynamic regulation of Piasy subcellular localization by the Trim32 E3 ligase scaffold protein and the role of these interactions in survival pathways in epidermal keratinocytes; 2) examine the role of Trim32 and Piasy in initiation, promotion and malignant progression in keratinocytes during epidermal carcinogenesis; 3) explore the predictive value of Trim32/Piasy status in human skin and head and neck SCC prognosis as a basis for future strategies for molecular targeting of Trim32/Piasy interactions or downstream effectors in cancer. The expression of Trim32 and Piasy beyond epithelia, such as in hematologic, muscle and neurological tissues and the presence of Trim32 inactivating mutations in two human hereditary syndromes imply broader significance of understanding Trim32 and Piasy regulation in human disease. PROJECT NARRATIVE Trim32 and Piasy: Two enzymes with opposing roles in cancer development Trim32 is a ¿scaffold¿ protein that controls the timing and location of other proteins that must interact appropriately to cause normal tissue development and that, if abnormal, can lead to cancer. We have shown that Trim32 adds a small molecule ¿ubiquitin¿ and destroys Piasy (an enzyme that is needed for tumor suppression and cell survival mediated by important gene regulators p53, NFB, STAT and Smad/TGFbeta), providing the first evidence for how Piasy is regulated in cells. Understanding how the very earliest changes detectable in cancer, such as Trim32 activation, extend abnormal cell survival and promote further changes (activation of cancer genes and inactivation of tumor suppressor genes) provides a basis for novel selective, less toxic molecular-targeted prevention and therapy of skin cancers and perhaps cancers from other tissues where Trim32 and Piasy are expressed, such as chronic myelogenous leukemia, muscle and brain tumors.