Introduction Immunotherapy is becoming a promising approach for unresectable-hepatocellular carcinoma (HCC); the anti-tumor response is affected by the tumor microenvironment (TME). Although Wnt/β-catenin mutations are reported to cause non-inflamed phenotype, their role on TME remains controversial. We aimed to clarify the heterogeneity of immunophenotype in HCC with Wnt/β-catenin mutations. Methods This study includes 152 resected HCCs; mutations in the catenin beta-1, adenomatous polyposis coli, or AXIN1, or AXIN2 genes were defined as Wnt/β-catenin mutations. With hierarchical cluster analyses, TME was classified into inflamed or non-inflamed classes based on the gene expressions associated with T-cell activation. Expression profiles of molecules related to cell differentiation and biliary-stem cell markers were compared between the TME classes to investigate whether differences in tumor traits were associated with TME. Results Forty of 152 (26.3%) HCCs carried the Wnt/β-catenin mutations. Of these, 33 were classified as non-inflamed (33/40, 82.5%) and 7 as inflamed (7/40, 17.5%). Non-inflamed class was characterized by low number of CD3+, CD4+, and CD8+ cells on immunostaining, and high mRNA expressions of AXIN2 and GLUL, which are involved in the canonical Wnt/β-catenin signaling and hepatocyte differentiation, respectively. Non-inflamed tumors showed higher enhancement on the hepatobiliary-phase of gadolinium-ethoxybenzyl-diethylenetriamine (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) compared to inflamed tumors. HCCs classified as inflamed class are revealed to have high numbers of CD3+, CD4+, and CD8+ tumor infiltrating lymphocytes on immunostaining. This class is associated with increased expression of anti-epithelial cell adhesion molecule and FOXM1 accompanied by upregulation of genes related to interferon-gamma signaling, dendritic cell migration, regulatory T cells, and myeloid-derived suppressor cell activation and recognized as low enhancement nodule on Gd-EOB-DTPA-enhanced MRI. Conclusion Heterogeneity of tumor traits and TME was observed in HCC with Wnt/β-catenin mutation. The potential was indicated that tumor traits and TME are determined not only by the activation of the HNF4A but also by FOXM1, both of which are downstream transcription factor of the Wnt/β-catenin signaling pathway.

中文翻译：

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具有 Wnt/β-Catenin 突变的人肝细胞癌免疫微环境的两个独特特征。


简介 免疫疗法正在成为治疗不可切除的肝细胞癌 (HCC) 的一种有前景的方法。抗肿瘤反应受到肿瘤微环境（TME）的影响。尽管据报道 Wnt/β-catenin 突变会导致非炎症表型，但它们在 TME 中的作用仍然存在争议。我们的目的是阐明 Wnt/β-catenin 突变 HCC 免疫表型的异质性。方法 本研究包括 152 例切除的 HCC；连环蛋白β-1、腺瘤性息肉病大肠杆菌、AXIN1 或 AXIN2 基因的突变被定义为 Wnt/β-连环蛋白突变。通过层次聚类分析，根据与 T 细胞激活相关的基因表达，将 TME 分为炎症类或非炎症类。对 TME 类别之间与细胞分化和胆道干细胞标记物相关的分子的表达谱进行比较，以研究肿瘤性状的差异是否与 TME 相关。结果 152 例 HCC 中有 40 例 (26.3%) 携带 Wnt/β-catenin 突变。其中，33 例被分类为非炎症（33/40，82.5%），7 例被分类为炎症（7/40，17.5%）。非炎症类的特点是免疫染色中 CD3+、CD4+ 和 CD8+ 细胞数量较少，而 AXIN2 和 GLUL mRNA 表达较高，它们分别参与经典的 Wnt/β-catenin 信号传导和肝细胞分化。与炎症肿瘤相比，非炎症肿瘤在钆-乙氧基苯甲基-二亚乙基三胺 (Gd-EOB-DTPA) 增强磁共振成像 (MRI) 的肝胆相上显示出更高的增强。免疫染色显示，分类为炎症类的 HCC 具有大量 CD3+、CD4+ 和 CD8+ 肿瘤浸润淋巴细胞。 此类与抗上皮细胞粘附分子和 FOXM1 表达增加相关，并伴有与干扰素-γ信号传导、树突状细胞迁移、调节性 T 细胞和骨髓源性抑制细胞激活相关的基因上调，并被认为是低强化结节。 Gd-EOB-DTPA 增强 MRI。结论 Wnt/β-catenin 突变的 HCC 中观察到肿瘤性状和 TME 的异质性。研究表明，肿瘤性状和 TME 不仅由 HNF4A 的激活决定，还由 FOXM1 决定，两者都是 Wnt/β-catenin 信号通路的下游转录因子。