PDF(Pubmed)
Abstract：
Pheochromocytomas (PCCs) are rare neuroendocrine tumors that originate from chromaffin cells in the adrenal gland. However, the cellular molecular characteristics and immune microenvironment of PCCs are incompletely understood. Here, we performed single-cell RNA sequencing (scRNA-seq) on 16 tissues from 4 sporadic unclassified PCC patients and 1 hereditary PCC patient with Von Hippel-Lindau (VHL) syndrome. We found that intra-tumoral heterogeneity was less extensive than the inter-individual heterogeneity of PCCs. Further, the unclassified PCC patients were divided into two types, metabolism-type (marked by NDUFA4L2 and COX4I2) and kinase-type (marked by RET and PNMT), validated by immunohistochemical staining. Trajectory analysis of tumor evolution revealed that metabolism-type PCC cells display phenotype of consistently active metabolism and increased metastasis potential, while kinase-type PCC cells showed decreased epinephrine synthesis and neuron-like phenotypes. Cell-cell communication analysis showed activation of the annexin pathway and a strong inflammation reaction in metabolism-type PCCs and activation of FGF signaling in the kinase-type PCC. Although multispectral immunofluorescence staining showed a lack of CD8+ T cell infiltration in both metabolism-type and kinase-type PCCs, only the kinase-type PCC exhibited downregulation of HLA-I molecules that possibly regulated by RET, suggesting the potential of combined therapy with kinase inhibitors and immunotherapy for kinase-type PCCs; in contrast, the application of immunotherapy to metabolism-type PCCs (with antigen presentation ability) is likely unsuitable. Our study presents a single-cell transcriptomics-based molecular classification and microenvironment characterization of PCCs, providing clues for potential therapeutic strategies to treat PCCs.
摘要：
嗜铬细胞瘤（PCCs）是罕见的神经内分泌肿瘤，起源于肾上腺的嗜铬细胞。然而,PCCs的细胞分子特征和免疫微环境尚未完全了解。这里,我们对4例散发性未分类PCC患者和1例VonHippel-Lindau综合征(VHL)遗传性PCC患者的16个组织进行了单细胞RNA测序(scRNA-seq).我们发现肿瘤内异质性不如PCCs个体间异质性广泛。Further,未分类的PCC患者分为两种类型，代谢型（由NDUFA4L2和COX4I2标记）和激酶型（由RET和PNMT标记），通过免疫组织化学染色验证。肿瘤演变的轨迹分析显示，代谢型PCC细胞表现出持续活跃的代谢表型和增加的转移潜力，而激酶型PCC细胞显示肾上腺素合成减少和神经元样表型。细胞-细胞通讯分析显示，在代谢型PCC中膜联蛋白途径的激活和强烈的炎症反应，在激酶型PCC中FGF信号的激活。尽管多光谱免疫荧光染色显示在代谢型和激酶型PCCs中均缺乏CD8+T细胞浸润,只有激酶型PCC表现出可能由RET调节的HLA-I分子的下调，提示激酶抑制剂联合治疗和免疫治疗激酶型PCCs的潜力；相反，将免疫疗法应用于代谢型PCCs(具有抗原呈递能力)可能不合适.我们的研究提出了基于单细胞转录组学的PCCs分子分类和微环境表征，为治疗PCCs的潜在治疗策略提供线索。
