Interferon regulation by NBR1-driven chaperone-mediated autophagy in stellate cells in liver cancer

项目总结 这项提议的长期目标是了解肿瘤的分子和细胞机制。 控制肝细胞癌(HCC)发展的微环境，特别关注 肝星状细胞(HSCs)在这一过程中扮演中心角色。而很明显，非实质的激活 细胞是肝脏肿瘤发生的关键因素，不幸的是，我们对其分子机制的了解 其中关键的间质和免疫细胞群调控的肝细胞癌的启动和进展仍然是零散的。 活化的HSC是肝纤维化和炎症的关键因素。目前的建议是基于我们的 先前发表的结果表明，在造血干细胞中，自噬和信号转接器p62被减少。 在小鼠中，无论是全局的还是HSC特异性的，它的失活都会促进肝癌的发生，这是因为 肝星状细胞的炎症和纤维化活性过度激活。我们新的未公布的初步结果 证明了NBR1的基因消融，无论是全局的还是选择性的，在HSCs中，完全逆转了亲... P62缺乏在造血干细胞中的致瘤作用。然而，NBR1缺陷的这种意想不到的影响不会恢复 P62缺失的促纤维化、TGFb驱动的作用，不影响自噬，但导致过度激活 干扰素(干扰素)的级联作用使CD8+T细胞更加活跃，增强抗肿瘤免疫监视。 我们的初步数据还表明，这种干扰素途径的过度激活是由于伴侣- 介导的自噬(CMA)。因此，在这项提案中，我们打算解开NBR1 促进CMA抑制干扰素的激活。我们还将确定由于停用 HSCs中的NBR1导致肿瘤微环境的重新编程，以抑制肿瘤的发生。为此， 我们将基于我们的初步数据来解决以下关键问题：(目标1)建立分子 NBR1调节HSCs干扰素应答的机制(Aim 1.1) 和p62对HSC中CMA活性的失活；(目标1.2)确定CMA对NBR1的功能贡献- 介导的干扰素在肝星状细胞中的调节；以及(目标1.3)确定NBR1 监管CMA。我们还将(目标2)确定NBR1对HSC激活和创建 肿瘤抑制微环境(目标2.1)确定NBR1缺失在HSCs中的影响 肝癌的肿瘤微环境；(目标2.2)确定CMA-STING-干扰素的功能贡献 Axis在NBR1缺陷的HSCs中对体内肝癌进展的影响；以及(Aim 2.3)确定NBR1缺失在 造血干细胞在肝细胞癌治疗反应中的作用及其相关性。这些研究的结果将有助于识别新的 预防和治疗肝癌的生物标志物和非实质性治疗新靶点。

PROJECT SUMMARY The long-term goal of this proposal is to understand the molecular and cellular mechanisms in the tumor microenvironment that govern hepatocellular carcinoma (HCC) development, with a special focus on the role of hepatic stellate cells (HSCs) as central players in this process. While it is clear that activation of non-parenchymal cells is a key contributor to liver tumorigenesis, unfortunately, our knowledge of the molecular mechanisms whereby key stromal and immune cell populations regulated HCC initiation and progression still is fragmentary. Activated HSCs are key contributors to liver fibrosis and inflammation. The present proposal is based on our previously published results demonstrating that the autophagy and signaling adaptor p62 is reduced in HSCs from HCC patients and that its inactivation in mice, either globally or HSC-specific, promoted HCC due to the hyperactivation of the inflammatory and fibrotic activities of HSCs. Our new unpublished preliminary results demonstrate that the genetic ablation of NBR1, either globally or selectively in HSCs, completely reverts the pro- tumorigenic role of p62 deficiency in HSCs. However, this unexpected effect of NBR1 deficiency does not revert the pro-fibrotic, TGFb-driven effect of p62 loss and did not affect autophagy but resulted in the hyperactivation of the interferon (IFN) cascade that renders CD8+ T cells more active, increasing anti-tumor immunosurveillance. Our preliminary data also suggest that this hyperactivation of the IFN pathways is due to impaired chaperone- mediated autophagy (CMA). Therefore, in this proposal we intend to unravel the mechanisms whereby NBR1 promotes CMA to restrain IFN activation. We will also establish how reduced CMA due to the inactivation of NBR1 in HSCs results in the reprograming of the tumor microenvironment to repress tumorigenesis. To that end, we will build on our preliminary data to address the following critical questions: (Aim 1) Establish the molecular mechanisms whereby NBR1 regulates the IFN response in HSCs by (Aim 1.1) determining the effect of NBR1 and p62 inactivation on CMA activity in HSCs; (Aim 1.2) determining the functional contribution of CMA to NBR1- mediated IFN regulation in HSCs; and (Aim 1.3) determining the molecular mechanisms whereby NBR1 regulates CMA. We will also (Aim 2) establish the contribution of NBR1 to HSC activation and the creation of a tumor-suppressive microenvironment by (Aim 2.1) determining the impact that NBR1 deletion in HSCs has in the tumor microenvironment of HCC; (Aim 2.2) determining the functional contribution of the CMA-STING-IFN axis in NBR1-deficient HSCs to HCC progression in vivo; and (Aim 2.3) determining the impact of NBR1 loss in HSCs in therapy response and its relevance in human HCC. Results from these studies will serve to identify new biomarkers as well as non-parenchymal new therapeutic targets for the prevention and treatment of HCC.