Pathogenesis and Novel Therapeutic Targets of Fatty Liver Disease and Cancer

我们的实验室一直在积极研究酒精相关性肝病的发病机制，重点是酒精相关性肝炎和肝癌中炎性细胞的特征。我们已经鉴定了miR-223，这是一种在酒精相关性肝病中高度升高的miRNA，在调节肿瘤环境和肝癌发展中起重要作用。 目前用于肝细胞癌（HCC）的阻断血管生成和免疫抑制的治疗仅为患有HCC的患者的子集提供一些益处，因此优化的治疗方案是未满足的需求。解决这些需求需要彻底了解肿瘤细胞协调炎症肿瘤微环境与显著骨髓细胞浸润的潜在机制。microRNA-223（miR-223）在骨髓细胞中高度表达，但其在调节肿瘤微环境中的作用尚不清楚。对野生型和miR-223敲除小鼠进行两种炎症相关HCC小鼠模型，所述小鼠模型通过注射二乙基亚硝胺（DEN）或在慢性四氯化碳（CCl 4）处理的小鼠中原位HCC细胞植入诱导。miR-223基因缺失显著加重炎症相关HCC的肿瘤发生。与野生型小鼠相比，DEN+ CCl 4给药后，miR-223敲除小鼠有更多的程序性细胞死亡1（PD-1+）T细胞和程序性细胞死亡配体1（PD-L1+）巨噬细胞浸润。RNA测序数据的生物信息学分析揭示了miR-223水平与肿瘤缺氧之间的强相关性，肿瘤缺氧是一种调节PD-1/PD-L1的条件。体内和体外机制研究表明，miR-223不直接靶向免疫细胞中的PD-1和PD-L1。相反，它通过抑制HCC中缺氧诱导因子1驱动的CD 39/CD 73-腺苷途径调节肿瘤微环境而间接下调它们。此外，在两种HCC模型中，通过腺病毒基因递送miR-223抑制了血管生成和缺氧介导的PD-1/PD-L1活化，从而阻碍了HCC进展。miR-223在调节缺氧诱导的肿瘤免疫抑制和血管生成中起着关键作用，可能成为HCC治疗的新靶点。

Our laboratory has been actively studying the pathogenesis of alcohol-associated liver disease, focusing on characterization of inflammatory cells in alcohol-associated hepatitis and liver cancer. we have identified miR-223, a miRNA that is highly elevated in alcohol-associated liver disease, and plays an important role in regulating tumor environment and liver cancer development. The current treatment for hepatocellular carcinoma (HCC) to block angiogenesis and immunosuppression provides some benefits only for a subset of patients with HCC, thus optimized therapeutic regimens are unmet needs. Addressing these needs require a thorough understanding of the underlying mechanisms by which tumor cells orchestrate an inflamed tumor microenvironment with significant myeloid cell infiltration. MicroRNA-223 (miR-223) is highly expressed in myeloid cells but its role in regulating tumor microenvironment remains unknown. Wild-type and miR-223 knockout mice were subjected to two mouse models of inflammation-associated HCC induced by injection of diethylnitrosamine (DEN) or orthotopic HCC cell implantation in chronic carbon tetrachloride (CCl4)-treated mice. Genetic deletion of miR-223 markedly exacerbated tumorigenesis in inflammation-associated HCC. Compared with wild-type mice, miR-223 knockout mice had more infiltrated programmed cell death 1 (PD-1+) T cells and programmed cell death ligand 1 (PD-L1+) macrophages after DEN+CCl4 administration. Bioinformatic analyses of RNA sequencing data revealed a strong correlation between miR-223 levels and tumor hypoxia, a condition that is well-documented to regulate PD-1/PD-L1. In vivo and in vitro mechanistic studies demonstrated that miR-223 did not directly target PD-1 and PD-L1 in immune cells. Rather, it indirectly downregulated them by modulating tumor microenvironment via the suppression of ha ypoxia-inducible factor 1-driven CD39/CD73-adenosine pathway in HCC. Moreover, gene delivery of miR-223 via adenovirus inhibited angiogenesis and hypoxia-mediated PD-1/PD-L1 activation in both HCC models, thereby hindering HCC progression. The miR-223 plays a critical role in modulating hypoxia-induced tumor immunosuppression and angiogenesis, which may serve as a novel therapeutic target for HCC.