硬癌性肝细胞癌（SHCC）是肝细胞癌（HCC）的一种特殊亚型，其特点是肿瘤微环境中丰富的纤维基质。然而，SHCC的分子特征尚不清楚，这对于开发专门的SHCC治疗方法至关重要。我们对134名患者的SHCC和常见HCC样本进行了单细胞RNA测序、全外显子组测序和批量RNA测序的综合分析，以描绘SHCC的基因组特征、转录组剖析和基质免疫微环境。我们进行了多重免疫荧光染色、流式细胞术和功能实验以进行验证。在这里，我们发现SHCC在基因组异质性较少的情况下，具有与常见HCC不同的独特转录组剖析。与常见HCC相比，硬癌性肝细胞癌（SHCC）中胰岛素样生长因子2（IGF2）在肿瘤细胞中显著升高，并可能作为SHCC的潜在诊断生物标志物。我们观察到SHCC中出现了显著的肿瘤基质重塑和缺氧，伴有基质癌相关成纤维细胞的富集和缺氧途径的上调。IGF2被确定为塑造SHCC缺氧基质微环境的关键介质。在这种微环境下，SHCC表现出与增强的血管内皮生长因子A信号通路相关的免疫抑制微环境，其中CD4+T细胞和CD8+T细胞功能异常。此外，我们发现来自SHCC肿瘤细胞的另一种缺氧相关分子SPP1通过SPP1-CD44轴抑制了树突状细胞的功能，并可能阻碍了T细胞的激活。我们揭示了SHCC的基因组特征，并揭示了SHCC中缺氧驱动的肿瘤基质重塑和免疫抑制微环境。版权所有©2023年美国肝脏疾病研究协会。

Scirrhous hepatocellular carcinoma (SHCC) is one of the unique subtypes of hepatocellular carcinoma (HCC), characterized by abundant fibrous stroma in tumor microenvironment. However, it remains unclear about the molecular traits of SHCC, which is essential to develop specialized therapeutic approaches for SHCC.We presented an integrative analysis containing single-cell RNA-sequencing, whole-exome sequencing, and bulk RNA-sequencing in SHCC and usual HCC samples from 134 patients, to delineate genomic features, transcriptomic profiles, and stromal immune microenvironment of SHCC. Multiplexed immunofluorescence staining, flow cytometry, and functional experiments were performed for validation. Here, we identified SHCC presented with less genomic heterogeneity while possessed a unique transcriptomic profile different from usual HCC. Insulin-like growth factor 2 (IGF2) was significantly upregulated in SHCC tumor cells comparing to usual HCC, and could serve as a potential diagnostic biomarker for SHCC. Significant tumor stromal remodeling and hypoxia were observed in SHCC with enrichment of matrix cancer-associated fibroblasts and upregulation of hypoxic pathways. And IGF2 was identified as a key mediator in shaping the hypoxic stromal microenvironment of SHCC. Under this microenvironment, SHCC exhibited an immunosuppressive niche correlated to enhanced vascular-endothelial-growth-factor A signaling activity, where CD4+T cells and CD8+T cells were dysfunctional. Furthermore, we found another hypoxic-related molecule SPP1 from SHCC tumor cells suppressed the function of dendritic cells via SPP1-CD44 axis, which also probably hindered the activation of T cells.We uncovered the genomic characteristics of SHCC, and revealed a hypoxia-driven tumor stroma remodeling and immunosuppressive microenvironment in SHCC.Copyright © 2023 American Association for the Study of Liver Diseases.