引言：清晰的肾细胞癌(ccRCC)与不利的临床结果相关联。为了确定可行的治疗靶点，对肿瘤内部异质性的全面理解至关重要。在本研究中，我们进行了生物信息学分析，以审查ccRCC肿瘤和癌旁样本的单细胞RNA测序数据，旨在阐明ccRCC肿瘤微环境(TME)的肿瘤内部异质性。方法：我们在七个ccRCC肿瘤和五个癌旁样本中鉴定并分组了总共51,780个单细胞，使用生物信息学分析将其分为11个细胞谱系。这些细胞谱系包括肿瘤细胞、髓样细胞、T细胞、成纤维细胞和内皮细胞，表明TME存在高度异质性。我们进行了拷贝数变异(CNV)分析，比较了肿瘤和正常细胞之间的CNV频率。髓样细胞人群进一步被重新聚类为三个主要亚群：单核细胞、巨噬细胞和树突细胞。我们采用差异表达分析、基因本体论和基因集富集分析来评估ccRCC TME内部群集和群集功能异质性。结果：我们的发现显示TME中的免疫细胞主要采用炎症抑制状态，促进肿瘤细胞生长和免疫逃逸。此外，与正常细胞相比，肿瘤细胞显示更高的CNV频率。髓样细胞亚群表现出不同的功能特性，单核细胞、巨噬细胞和树突细胞在TME中展示了多样的角色。某些免疫细胞表现出促肿瘤和免疫抑制作用，而另一些则显示出抗肿瘤和免疫刺激性特性。结论：该研究有助于了解ccRCC TME中的肿瘤内部异质性，并为ccRCC治疗提供潜在的治疗靶点。研究结果强调了在进行有效的治疗干预时考虑TME中免疫细胞的多样功能角色的重要性。 版权所有 © 2023 王，王，刘，高，李，李和周。

Introduction: Clear cell renal cell carcinoma (ccRCC) is associated with unfavorable clinical outcomes. To identify viable therapeutic targets, a comprehensive understanding of intratumoral heterogeneity is crucial. In this study, we conducted bioinformatic analysis to scrutinize single-cell RNA sequencing data of ccRCC tumor and para-tumor samples, aiming to elucidate the intratumoral heterogeneity in the ccRCC tumor microenvironment (TME). Methods: A total of 51,780 single cells from seven ccRCC tumors and five para-tumor samples were identified and grouped into 11 cell lineages using bioinformatic analysis. These lineages included tumor cells, myeloid cells, T-cells, fibroblasts, and endothelial cells, indicating a high degree of heterogeneity in the TME. Copy number variation (CNV) analysis was performed to compare CNV frequencies between tumor and normal cells. The myeloid cell population was further re-clustered into three major subgroups: monocytes, macrophages, and dendritic cells. Differential expression analysis, gene ontology, and gene set enrichment analysis were employed to assess inter-cluster and intra-cluster functional heterogeneity within the ccRCC TME. Results: Our findings revealed that immune cells in the TME predominantly adopted an inflammatory suppression state, promoting tumor cell growth and immune evasion. Additionally, tumor cells exhibited higher CNV frequencies compared to normal cells. The myeloid cell subgroups demonstrated distinct functional properties, with monocytes, macrophages, and dendritic cells displaying diverse roles in the TME. Certain immune cells exhibited pro-tumor and immunosuppressive effects, while others demonstrated antitumor and immunostimulatory properties. Conclusion: This study contributes to the understanding of intratumoral heterogeneity in the ccRCC TME and provides potential therapeutic targets for ccRCC treatment. The findings emphasize the importance of considering the diverse functional roles of immune cells in the TME for effective therapeutic interventions.Copyright © 2023 Wang, Wang, Liu, Gao, Li, Li and Zhou.