Role of the Parkinson's susceptibility gene LRRK2 in NFAT-mediated malignant mesothelioma tumorigenesis

项目总结/摘要 恶性间皮瘤（MM），特别是胸膜形式的这种疾病，是一种治疗耐药，迅速致命的， 衬在身体内部空腔的浆膜细胞的癌症。暴露于石棉是因果关系与 在MM的发展中，石棉诱导的炎症是这一过程的主要促成因素。在一些 家族中，某些癌症相关基因（尤其是BAP 1）中的杂合种系突变易患MM， 携带Bap 1突变的小鼠模型对以下致癌作用的易感性增强： 石棉此外，体细胞BAP 1突变/缺失发生在50-60%的人MM标本中。我们最近 对有癌症家族史的MM患者进行的全基因组测序研究发现了两个家族， 帕金森病易感基因LRRK 2的种系突变，包括一个家族中的截短突变 其中6名同胞患上了胸膜多发性骨髓瘤。我们后来发现，在61%的原发性骨髓瘤患者中，LRRK 2蛋白表达缺失。 胸膜MPM和来自无关个体的MPM细胞系。LRRK 2与多种细胞 NFAT信号通路，其中之一（NFAT信号传导）涉及炎症/免疫反应和致癌作用。 我们广泛的长期目标是确定LRRK 2缺失是否有助于MM的形成和进展， 部分，通过失调NFAT，以及是否靶向这一途径将有显着的治疗效果。在 在这个项目中，我们建议测试LRRK 2介导的与NFAT的相互作用是否在石棉中发挥关键作用- 诱导的炎症和MM肿瘤发生。我们的假设是LRRK 2作为肿瘤抑制基因 在MM中，LRRK 2表达缺失对MM发病机制有重要作用，未来的治疗 利用与LRRK 2缺失相关的功能属性的方法可以改善临床结果 在这种疾病中。总的来说，该项目旨在阐明LRRK 2失活的机制， 石棉致癌作用和MM的发展使用细胞生物学和体内方法的组合。 我们提出以下具体目标：1）LRRK 2缺失是否促进石棉诱导的肿瘤发生？我们 将确定Lrrk 2缺陷小鼠是否易受石棉致癌作用的影响， 与野生型（WT）同窝仔相比，石棉诱导的MM发展加速。此外，我们将 确定Lrrk 2缺陷小鼠的肿瘤微环境与Lrrk 2缺陷小鼠的肿瘤微环境是否不同。 WT小鼠，并且如果在人MPM中发生可比较的差异。2)LRRK 2缺失是否增强NFAT驱动 炎症信号天冬氨酸被认为通过诱导炎症而促进MPM的发展， 我们建议测试LRRK 2是否通过抑制转录活性来抑制这种炎症， NFAT因子。已显示LRRK 2与NRON复合物结合，阻断NFAT从胞质溶胶的转运 在细胞处于静止状态的时候，因此，LRRK 2的缺失将导致NFAT 转移到细胞核以介导转录。在这里，我们将测试这种机制是否可以解释LRRK 2如何 损失可能增强石棉诱导的炎症和MM肿瘤发生。

PROJECT SUMMARY/ABSTRACT Malignant Mesothelioma (MM), particularly the pleural form of this disease, is a treatment-resistant, rapidly fatal cancer of serosal cells lining the internal body cavities. Exposure to asbestos is causally associated with the development of MM, and asbestos-induced inflammation is a major contributing factor in this process. In some families, heterozygous germline mutations in certain cancer-related genes, especially BAP1, predispose to MM, and mouse models carrying Bap1 mutations have enhanced susceptibility to the carcinogenic effects of asbestos. Moreover, somatic BAP1 mutations/deletions occur in 50-60% of human MM specimens. Our recent whole genome sequencing study of MM patients with a family history of cancer uncovered two families with germline mutations in the Parkinson’s susceptibility gene LRRK2, including a truncating mutation in one family in which 6 siblings developed pleural MM. We later found loss of LRRK2 protein expression in 61% of primary pleural MPMs and MPM cell lines from unrelated individuals. LRRK2 has been linked with various cellular pathways, one of which (NFAT signaling) is implicated in inflammation/immune response and carcinogenesis. Our broad, long-term objective is to determine if LRRK2 loss contributes to MM formation and progression, in part, by dysregulating NFAT, and whether targeting this pathway would have significant therapeutic benefits. In this project, we propose to test whether LRRK2-mediated interactions with NFAT play a key role in asbestos- induced inflammation and MM tumorigenesis. Our hypothesis is that LRRK2 acts as a tumor suppressor gene in MM, that loss of LRRK2 expression contributes significantly to MM pathogenesis, and that future therapeutic approaches exploiting functional attributes associated with LRRK2 loss can lead to improved clinical outcomes in this disease. Overall, this project seeks to elucidate mechanisms by which inactivation of LRRK2 contributes to asbestos carcinogenesis and MM development using a combination of cell biological and in vivo approaches. We propose the following Specific Aims: 1) Does LRRK2 loss promote asbestos-induced tumorigenesis? We will determine if Lrrk2-deficient mice are predisposed to the carcinogenic effects of asbestos, as demonstrated by accelerated asbestos-induced MM development compared to wild-type (WT) littermates. Additionally, we will ascertain if the immune tumor microenvironment differs between MMs from Lrrk2-deficient mice and MMs from WT mice, and if a comparable difference occurs in human MPM. 2) Does LRRK2 loss enhance NFAT-driven inflammatory signaling? Asbestos is thought to contribute to MPM development by inducing inflammation, and we propose to test whether LRRK2 suppresses such inflammation by dampening activity of the transcription factor NFAT. LRRK2 has been shown to bind to the NRON complex, blocking transport of NFAT from the cytosol to the nucleus when cells are in a resting state. Loss of LRRK2 will therefore be expected to cause NFAT to be translocated to the nucleus to mediate transcription. Here we will test if this mechanism may explain how LRRK2 loss may potentiate asbestos-induced inflammation and MM tumorigenesis.