PURPOSE Recurrent renal cell carcinoma(reRCC) is associated with poor prognosis and the underlying mechanism is not yet clear. A comprehensive understanding of tumor microenvironment (TME) of reRCC may aid in designing effective anticancer therapies, including immunotherapies. Single-cell transcriptomics holds great promise for investigating the TME, however, this technique has not been used in reRCC. Here, we aimed to explore the difference in the TME and gene expression pattern between primary RCC (pRCC) and reRCC at single-cell level. EXPERIMENTAL DESIGN We performed single-cell RNA sequencing analyses of 32,073 cells from 2 pRCC, 2 reRCC, and 3 adjacent normal kidney samples. 41 pairs of pRCC and reRCC samples were collected as a validation cohort to assess differences observed in single-cell sequencing. The prognostic significance of related cells and markers were studied in 47 RCC patients underwent immunotherapy. The function of related cells and markers were validated via in vitro and in vivo experiments. RESULTS reRCC had reduced CD8+ T cells but increased cancer-associated fibroblasts (CAFs) infiltration compared with pRCC. Reduced CD8+ T cells and increased CAFs infiltration were significantly associated with a worse response from immunotherapy. Remarkably, CAFs showed substantial expression of LGALS1 (Gal1). In vitro, CAFs could induce CD8+ T cells apoptosis via Gal1. In vivo, knockdown of Gal1 in CAFs suppressed tumor growth, increased CD8+ T cells infiltration, reduced the proportion of apoptotic CD8+ T cells and enhanced the efficacy of immunotherapy. CONCLUSIONS We delineated the heterogeneity of reRCC and highlighted an innovative mechanism that CAFs acted as a suppressor of CD8+ T cells via Gal1. Targeting Gal1 combined with anti-PD1 showed promising efficacy in treating RCC.

中文翻译：

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单细胞转录组学揭示了复发性肾细胞癌中成纤维细胞介导的低 CD8+ T 细胞浸润状态。

目的 复发性肾细胞癌（reRCC）与预后不良有关，其潜在机制尚不清楚。全面了解 reRCC 的肿瘤微环境 (TME) 可能有助于设计有效的抗癌疗法，包括免疫疗法。单细胞转录组学对研究 TME 具有很大的前景，但是，该技术尚未用于 reRCC。在这里，我们旨在探讨单细胞水平上原发性 RCC (pRCC) 和 reRCC 之间 TME 和基因表达模式的差异。实验设计 我们对来自 2 个 pRCC、2 个 reRCC 和 3 个相邻的正常肾脏样本的 32,073 个细胞进行了单细胞 RNA 测序分析。收集了 41 对 pRCC 和 reRCC 样本作为验证队列，以评估在单细胞测序中观察到的差异。在 47 名接受免疫治疗的 RCC 患者中研究了相关细胞和标志物的预后意义。通过体外和体内实验验证了相关细胞和标志物的功能。结果 与 pRCC 相比，reRCC 减少了 CD8+ T 细胞，但增加了癌症相关成纤维细胞 (CAF) 浸润。CD8+ T 细胞减少和 CAF 浸润增加与免疫治疗的较差反应显着相关。值得注意的是，CAFs 显示出 LGALS1 (Gal1) 的大量表达。在体外，CAFs 可以通过 Gal1 诱导 CD8+ T 细胞凋亡。在体内，CAFs 中 Gal1 的敲低抑制了肿瘤生长，增加了 CD8+ T 细胞浸润，降低了凋亡 CD8+ T 细胞的比例并增强了免疫治疗的功效。结论 我们描述了 reRCC 的异质性，并强调了 CAF 通过 Gal1 作为 CD8+ T 细胞抑制因子的创新机制。靶向 Gal1 联合抗 PD1 治疗 RCC 显示出有希望的疗效。