Novel arginine-methylation mediated regulation of YAP1 in K-Ras mutant lung adenocarcinomas

肺癌是美国癌症相关死亡的主要原因，占大多数，约85% 由非小细胞肺癌(NSCLC)引起。非小细胞肺癌的总体存活率很低，原因是 靶向治疗的反应和耐药性的发展。虽然免疫疗法对大约 然而，30%存在KRAS癌基因突变的患者并不能使绝大多数患者受益 病人们。在此背景下，研究表明，转录共激活蛋白，YAP1，下游 河马信号通路的介体，在河马的茎、生长和转移中起着重要作用。 非小细胞肺癌。在目前的研究中，我们发现一种非规范的I激酶，Tbk1(Tank-bindingKinase1)可以 物理上相互作用并使YAP1磷酸化。耗尽或抑制TBK1可显著提高血管紧张素转换酶 YAP1蛋白，在KRAS突变的肺癌细胞中选择性地表达。这是通过增强甲基化来实现的 精氨酸残基上的YAP1。已知TBK1在先天免疫中发挥重要作用，但其致癌作用 其作用，特别是在肺癌领域的作用，还没有完全阐明。我们建议的项目将调查 这种新的精氨酸的功能重要性--某些蛋白质精氨酸-甲基对YAP1蛋白的甲基化 转移酶(PRMTs)，尤其是PRMT4/CARM1和PRMT5。PAN-PRMT对这些PRMT的抑制作用 即使在TBK1耗竭的情况下，抑制剂也能显著下调YAP1的水平。这些小说 研究结果提出，同时抑制TBK1和PRMT可能是一种可行的策略，以 对抗非小细胞肺癌，我们将在一系列深入的体外和体内研究中检验这一点。具体目标 内容包括：(1)了解Tbk1在KRAS和KRAS中对YAP1的差异调控 EGFR突变的肺腺癌和(2)研究新的YAP1分子甲基化状态。 KRAS突变背景中的TBK1缺失导致了YAP1蛋白的稳定性。

Lung cancer is the leading cause of cancer-related death in the United States, with a majority, around 85% resulting from non-small cell lung cancer (NSCLC). The overall survival rate for NSCLC is low, due to poor response to targeted therapy and the development of resistance. While immunotherapy is beneficial for about 30% of patients that harbor mutations in the KRAS oncogene, however, does not benefit the vast majority of the patients. In this context, studies showed that the transcriptional co-activator protein, YAP1, a downstream mediator of the Hippo signaling pathway, plays a major role in the stemness, growth, and metastasis of NSCLCs. In the present study, we find that a non-canonical I kinase, TBK1 (Tank-binding Kinase 1) can physically interact and phosphorylate YAP1. Depletion or inhibition of TBK1 significantly elevated the levels of the YAP1 protein, selectively in KRAS mutant lung cancer cells. This occurred through enhanced methylation of YAP1 on arginine residues. TBK1 is known to play an important role in innate immunity but its oncogenic role, especially in the field of lung cancer, is not fully elucidated. Our proposed project will investigate the functional importance of this novel arginine-methylation of YAP1 protein by certain protein arginine-methyl transferases (PRMTs), especially PRMT4/CARM1 and PRMT5. Inhibition of these PRMTs by a pan-PRMT inhibitor significantly downregulated the levels of YAP1 even in the TBK1 depleted condition. These novel findings raise the possibility that inhibiting TBK1 and PRMTs simultaneously might be a viable strategy to combat NSCLCs, and we will examine this in a series of in-depth in vitro and in vivo studies. The Specific Aims which will be covered are: (1) To understand the differential regulation of YAP1 by TBK1 in KRAS versus EGFR mutant lung adenocarcinoma and (2) To study the novel methylation status of YAP1 molecule under TBK1 depletion in KRAS mutant background leading to YAP1 protein stability.