Department of Medical Oncology and Therapeutics Research, City of Hope Comprehensive Cancer Center, Duarte, CA, United States.
Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY, United States.
Front Immunol. 2023 Aug 11;14:1182581. doi: 10.3389/fimmu.2023.1182581. eCollection 2023.
To characterize and further compare the immune cell populations of the tumor microenvironment (TME) in both clear cell and papillary renal cell carcinoma (RCC) using heavy metal-labeled antibodies in a multiplexed imaging approach (imaging mass cytometry).
Formalin-fixed paraffin-embedded (FFPE) baseline tumor tissues from metastatic patients with clear cell renal cell carcinoma (ccRCC) and papillary renal cell carcinoma (pRCC) were retrospectively requisitioned from an institutional biorepository. Pretreated FFPE samples from 33 RCC patients (10 ccRCC, 23 pRCC) were accessioned and stained for imaging mass cytometry (IMC) analysis. Clinical characteristics were curated from an institutional RCC database. FFPE samples were prepared and stained with heavy metal-conjugated antibodies for IMC. An 11-marker panel of tumor stromal and immune markers was used to assess and quantify cellular relationships in TME compartments. To validate our time-of-flight (CyTOF) analysis, we cross-validated findings with The Cancer Genome Atlas Program (TCGA) analysis and utilized the CIBERSORTx tool to examine the abundance of main immune cell types in pRCC and ccRCC patients.
Patients with ccRCC had a longer median overall survival than did those with pRCC (67.7 vs 26.8 mo, respectively). Significant differences were identified in the proportion of CD4 T cells between disease subtypes (ccRCC 14.1%, pRCC 7.0%, p<0.01). Further, the pRCC cohort had significantly more PanCK tumor cells than did the ccRCC cohort (24.3% vs 9.5%, respectively, p<0.01). There were no significant differences in macrophage composition (CD68) between cohorts. Our results demonstrated a significant correlation between the CyTOF and TCGA analyses, specifically validating that ccRCC patients exhibit higher levels of CD4 T cells (ccRCC 17.60%, pRCC 15.7%, p<0.01) and CD8 T cells (ccRCC 17.83%, pRCC 11.15%, p<0.01). The limitation of our CyTOF analysis was the large proportion of cells that were deemed non-characterizable.
Our findings emphasize the need to investigate the TME in distinct RCC histological subtypes. We observed a more immune infiltrative phenotype in the TME of the ccRCC cohort than in the pRCC cohort, where a tumor-rich phenotype was noted. As practical predictive biomarkers remain elusive across all subtypes of RCC, further studies are warranted to analyze the biomarker potential of such TME classifications.
使用多重成像方法（成像质谱细胞术）中的重金属标记抗体，对透明细胞和乳头状肾细胞癌（RCC）的肿瘤微环境（TME）中的免疫细胞群进行特征描述并进一步比较。
从机构生物库中回顾性索取患有透明细胞肾细胞癌（ccRCC）和乳头状肾细胞癌（pRCC）的转移性患者的福尔马林固定石蜡包埋（FFPE）基线肿瘤组织。对 33 名 RCC 患者（10 名 ccRCC，23 名 pRCC）的预处理 FFPE 样本进行了采集，并进行成像质谱细胞术（IMC）分析染色。从机构 RCC 数据库中整理了临床特征。FFPE 样本用重金属偶联抗体进行 IMC 染色。使用 11 种肿瘤基质和免疫标志物的标志物面板来评估和量化 TME 隔室中的细胞关系。为了验证我们的飞行时间（CyTOF）分析，我们使用 TCGA 分析对发现结果进行了交叉验证，并利用 CIBERSORTx 工具来检查 pRCC 和 ccRCC 患者中主要免疫细胞类型的丰度。
ccRCC 患者的中位总生存期长于 pRCC 患者（分别为 67.7 个月和 26.8 个月）。疾病亚型之间 CD4 T 细胞的比例存在显著差异（ccRCC 为 14.1%，pRCC 为 7.0%，p<0.01）。此外，pRCC 队列的 PanCK 肿瘤细胞明显多于 ccRCC 队列（分别为 24.3%和 9.5%，p<0.01）。两个队列之间的巨噬细胞组成（CD68）没有显著差异。我们的结果表明 CyTOF 和 TCGA 分析之间存在显著相关性，特别是验证了 ccRCC 患者具有更高水平的 CD4 T 细胞（ccRCC 为 17.60%，pRCC 为 15.7%，p<0.01）和 CD8 T 细胞（ccRCC 为 17.83%，pRCC 为 11.15%，p<0.01）。我们的 CyTOF 分析的局限性在于很大比例的细胞被认为是不可描述的。
我们的研究结果强调了需要对不同的 RCC 组织学亚型的 TME 进行研究。我们观察到 ccRCC 队列的 TME 中存在更具免疫浸润性的表型，而在 pRCC 队列中则存在以肿瘤为主的表型。由于在所有 RCC 亚型中实用的预测性生物标志物仍然难以捉摸，因此需要进一步研究来分析这种 TME 分类的生物标志物潜力。
