Purpose

High levels of heterogeneity and immunosuppression characterize the HCC immune microenvironment (TME). Unfortunately, the majority of hepatocellular carcinoma (HCC) patients do not benefit from immune checkpoint inhibitors (ICIs) therapy. New small molecule therapies for the treatment of HCC are the goal of our research.

Methods

SUMOylation inhibitors (TAK-981 and ML-792) were evaluated for the treatment of preclinical mouse HCC models (including subcutaneous and orthotopic HCC models). We profile immune cell subsets from tumor samples after SUMOylation inhibitors treatment using single-cell RNA sequencing (scRNA-seq), mass cytometry (CyTOF), flow cytometry, and multiple immunofluorescences (mIF).

Results

We discover that SUMOylation is higher in HCC patient samples compared to normal liver tissue. TAK-981 and ML-792 decrease SUMOylation at nanomolar levels in HCC cells and also successfully reduced the tumor burden. Analysis combining scRNA-seq and CyTOF demonstrate that treatment with SUMOylation inhibitors reduces the exhausted CD8⁺T (T_ex) cells while enhancing the cytotoxic NK cells, M1 macrophages and cytotoxic T lymphocytes (CTL) in preclinical mouse HCC model. Furthermore, SUMOylation inhibitors have the potential to activate innate immune signals from CD8⁺T, NK and macrophages while promoting TNFα and IL-17 secretion. Most notably, SUMOylation inhibitors can directly alter the TME by adjusting the abundance of intestinal microbiota, thereby restoring anti-tumor immunity in HCC models.

Conclusions

This preclinical study suggests that SUMO signaling inhibitors may be beneficial for the treatment of HCC.

Graphical abstract

中文翻译：

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SUMO化抑制剂通过重塑肝细胞癌临床前模型中的免疫微环境来激活抗肿瘤免疫

目的

HCC 免疫微环境 (TME) 具有高度异质性和免疫抑制的特征。不幸的是，大多数肝细胞癌（HCC）患者无法从免疫检查点抑制剂（ICIs）治疗中受益。治疗 HCC 的新小分子疗法是我们研究的目标。

方法

对 SUMO 化抑制剂（TAK-981 和 ML-792）对临床前小鼠 HCC 模型（包括皮下和原位 HCC 模型）的治疗进行了评估。我们使用单细胞 RNA 测序 (scRNA-seq)、质谱流式细胞术 (CyTOF)、流式细胞术和多重免疫荧光 (mIF) 分析 SUMO 化抑制剂治疗后肿瘤样本的免疫细胞亚群。

结果

我们发现，与正常肝组织相比，HCC 患者样本中的 SUMO 化程度更高。TAK-981 和 ML-792 在 HCC 细胞中以纳摩尔水平降低 SUMOylation，并成功减轻肿瘤负荷。结合 scRNA-seq 和 CyTOF 的分析表明，在临床前小鼠 HCC 模型中，SUMOylation 抑制剂治疗可减少耗竭的 CD8 ⁺ T (T _ex ) 细胞，同时增强细胞毒性 NK 细胞、M1 巨噬细胞和细胞毒性 T 淋巴细胞 (CTL)。此外，SUMOylation 抑制剂有可能激活 CD8 ⁺ T、NK 和巨噬细胞的先天免疫信号，同时促进 TNFα 和 IL-17 的分泌。最值得注意的是，SUMO化抑制剂可以通过调节肠道微生物群的丰度来直接改变TME，从而恢复HCC模型中的抗肿瘤免疫力。

结论

这项临床前研究表明 SUMO 信号抑制剂可能有益于 HCC 的治疗。

图形概要