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

项目摘要/摘要 恶性间皮瘤(MM)，尤其是胸膜间皮瘤，是一种耐药、迅速致死的疾病。 位于体内腔内的浆膜细胞癌。暴露在石棉中与 多发性骨髓瘤的发展，石棉引起的炎症是这一过程中的一个主要因素。在一些 家系，某些癌症相关基因，特别是BAP1的杂合胚系突变，易患MM， 携带BAP1突变的小鼠模型增强了对BAP1致癌作用的敏感性 石棉。此外，体细胞BAP1突变/缺失发生在50-60%的人类多发性骨髓瘤标本中。我们最近 有癌症家族史的多发性骨髓瘤患者的全基因组测序研究发现两个家系 帕金森病易感基因LRRK2的胚系突变，包括一个家系的截短突变 其中6个兄弟姐妹发展为胸膜MM。我们后来发现在61%的原发性MM中LRRK2蛋白表达缺失 胸膜MPM和来自无关个体的MPM细胞系。LRRK2与多种细胞 途径，其中之一(NFAT信号)与炎症/免疫反应和癌症的发生有关。 我们广泛的、长期的目标是确定LRRK2缺失是否有助于多发性骨髓瘤的形成和进展 部分是通过失调NFAT，以及靶向这一途径是否会有显著的治疗益处。在……里面 在这个项目中，我们建议测试LRRK2介导的与NFAT的相互作用是否在石棉- 诱导炎症与多发性骨髓瘤的发生。我们的假设是LRRK2作为肿瘤抑制基因 在多发性骨髓瘤中，LRRK2表达缺失在多发性骨髓瘤的发病机制中起着重要作用，而且未来的治疗 利用与LRRK2丢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。总体而言，该项目试图阐明LRRK2失活有助于 使用细胞生物学和体内方法相结合的方法来促进石棉的致癌和多发性骨髓瘤的发展。 我们提出了以下具体目标：1)LRRK2缺失是否促进石棉诱导的肿瘤发生？我们 将确定LRRK2基因缺陷的小鼠是否容易受到石棉致癌作用的影响，正如所证明的那样 与野生型(WT)产仔相比，石棉诱导的MM发育加速。此外，我们还将 确定LRRK2缺陷小鼠的MMS和MMS之间的免疫肿瘤微环境是否不同 WT小鼠，如果在人类MPM中出现类似的差异。2)LRRK2损失是否增强了NFAT驱动 发炎信号？石棉被认为通过引起炎症而促进MPM的发展，以及 我们建议测试LRRK2是否通过抑制转录活性来抑制这种炎症 因数NFAT。LRRK2已被证明与NRON复合体结合，阻断NFAT从胞浆的运输 当细胞处于静息状态时，向细胞核发出信号。因此，LRRK2的丢失预计将导致NFAT 转位到细胞核以调节转录。在这里，我们将测试这一机制是否可以解释LRRK2 丢失可能会加剧石棉引起的炎症和多发性骨髓瘤的发生。

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.