Zhu Xin-Yu, Liu Wen-Ting, Hou Xiao-Juan, Zong Chen, Yu Wei, Shen Zhe-Min, Qu Shu-Ping, Tao Min, Xue Meng-Meng, Zhou Dao-Yu, Bai Hao-Ran, Gao Lu, Jiang Jing-Hua, Zhao Qiu-Dong, Wei Li-Xin, Yang Xue, Han Zhi-Peng, Zhang Li
Changhai Clinical Research Unit, Changhai Hospital of Naval Medical University, Shanghai, China; Tumor Immunology and Metabolism Center, National Center for Liver Cancer, Naval Medical University, Shanghai, China.
Tumor Immunology and Metabolism Center, National Center for Liver Cancer, Naval Medical University, Shanghai, China; Department of Medical Oncology, Fudan University Shanghai Cancer Center, Shanghai, China.
J Adv Res. 2024 Dec 12. doi: 10.1016/j.jare.2024.12.008.
The heterogeneity of hepatocellular carcinoma (HCC) is linked to tumor malignancy and poor prognosis. Nevertheless, the precise mechanisms underlying the development of the cholangiocellular phenotype (CCA) within HCC remain unclear. Emerging studies support that the cross-talk among the host cells within tumor microenvironment (TME) sustains the cancer cell plasticity.
This study sought to identify the specific cell types involved in the formation of CCA and to elucidate their functional roles in the progression of HCC.
Single-cell RNA sequencing was employed to identify the specific cell types involved in the formation of CCA. Both in vitro and vivo analyses were used to identify the tumor-associated senescent ECs and investigate the function in TME. The diethylnitrosamine-induced model was utilized to investigate the interaction between senescent ECs and MSCs, aiming to elucidate their synergistic contributions to the progression of CCA.
Using single-cell RNA sequencing, we identified a distinct senescent-associated subset of endothelial cells (ECs), namely CD34CLDN5 ECs, which mainly enriched in tumor tissue. Further, the senescent ECs were observed to secrete IGF2, which recruited mesenchymal stem cells (MSCs) into the TME through IGF2R/MAPK signaling. In primary liver cancer model, MSCs exhibited a strong tumor-promoting effect, increasing the CCA and tumor malignancy after HCC formation. Interestingly, knockdown of IGF2R expression in MSCs inhibited the increase of CCA caused by MSCs in HCC. Meanwhile, it was revealed that MSCs released multiple inflammatory and trophic-related cytokines to enhance the cancer stem cell-like characteristics in HCC cells. Finally, we demonstrated that CEBPβ up-regulated IGF2 expression in tumor senescent ECs by combining with Igf2-promtor-sequence.
Together, our findings illustrated that tumor associated senescent ECs in HCC recruited the MSCs into TME, enhancing cancer stem cell (CSC)-like features of HCC cells and contributing to the CCA formation.
肝细胞癌（HCC）的异质性与肿瘤恶性程度及预后不良相关。然而，HCC内胆管细胞表型（CCA）形成的精确机制仍不清楚。新兴研究支持肿瘤微环境（TME）中宿主细胞之间的相互作用维持了癌细胞的可塑性。
本研究旨在确定参与CCA形成的特定细胞类型，并阐明它们在HCC进展中的功能作用。
采用单细胞RNA测序来确定参与CCA形成的特定细胞类型。体外和体内分析均用于鉴定肿瘤相关的衰老内皮细胞（ECs）并研究其在TME中的功能。利用二乙基亚硝胺诱导的模型研究衰老ECs与间充质干细胞（MSCs）之间的相互作用，旨在阐明它们对CCA进展的协同作用。
通过单细胞RNA测序，我们鉴定出一种独特的衰老相关内皮细胞亚群，即CD34CLDN5 ECs，其主要富集于肿瘤组织中。此外，观察到衰老ECs分泌胰岛素样生长因子2（IGF2），其通过IGF2R/丝裂原活化蛋白激酶（MAPK）信号通路将间充质干细胞（MSCs）招募到TME中。在原发性肝癌模型中，MSCs表现出强大的肿瘤促进作用，在HCC形成后增加了CCA和肿瘤恶性程度。有趣的是，敲低MSCs中IGF2R的表达可抑制HCC中MSCs引起的CCA增加。同时，研究表明MSCs释放多种炎症和营养相关细胞因子以增强HCC细胞中癌干细胞样特征。最后，我们证明CCAAT增强子结合蛋白β（CEBPβ）通过与Igf2启动子序列结合上调肿瘤衰老ECs中IGF2的表达。
总之，我们的研究结果表明，HCC中肿瘤相关的衰老ECs将MSCs招募到TME中，增强了HCC细胞的癌干细胞（CSC）样特征并促进了CCA的形成。
