Renal cell carcinoma (RCC) treatment has improved in the last decade with the introduction of drugs targeting tumor angiogenesis. However, the 5-year survival of metastatic disease is still only 10-15%. Here, we explored the prognostic significance of compartment-specific expression of Neuropilin 1 (NRP1), a co-receptor for vascular endothelial growth factor (VEGF). NRP1 expression was analyzed in RCC tumor vessels, in perivascular tumor cells, and generally in the tumor cell compartment. Moreover, complex formation between NRP1 and the main VEGF receptor, VEGFR2, was determined. Two RCC tissue microarrays were used; a discovery cohort consisting of 64 patients and a validation cohort of 314 patients. VEGFR2/NRP1 complex formation in cis (on the same cell) and trans (between cells) configurations was determined by in situ proximity ligation assay (PLA), and NRP1 protein expression in three compartments (endothelial cells, perivascular tumor cells, and general tumor cell expression) was determined by immunofluorescent staining. Expression of NRP1 in perivascular tumor cells was explored as a marker for RCC survival in the two RCC cohorts. Results were further validated using a publicly available gene expression dataset of clear cell RCC (ccRCC). We found that VEGFR2/NRP1 trans complexes were detected in 75% of the patient samples. The presence of trans VEGFR2/NRP1 complexes or perivascular NRP1 expression was associated with a reduced tumor vessel density and size. When exploring NRP1 as a biomarker for RCC prognosis, perivascular NRP1 and general tumor cell NRP1 protein expression correlated with improved survival in the two independent cohorts, and significant results were obtained also at the mRNA level using the publicly available ccRCC gene expression dataset. Only perivascular NRP1 expression remained significant in multivariable analysis. Our work shows that perivascular NRP1 expression is an independent marker of improved survival in RCC patients, and reduces tumor vascularization by forming complexes in trans with VEGFR2 in the tumor endothelium. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

中文翻译：

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血管周围Neuropilin-1表达是肾细胞癌生存改善的独立标志。

在过去的十年中，随着针对肿瘤血管生成的药物的引入，肾细胞癌（RCC）的治疗得到了改善。但是，转移性疾病的5年生存率仍然只有10-15％。在这里，我们探讨了神经纤维蛋白1（NRP1），血管内皮生长因子（VEGF）的共同受体的隔室特异性表达的预后意义。在RCC肿瘤血管，血管周围肿瘤细胞中以及通常在肿瘤细胞区室中分析了NRP1表达。此外，确定了NRP1和主要VEGF受体VEGFR2之间的复合物形成。使用了两个RCC组织微阵列。由64位患者组成的发现队列和314位患者的验证队列。通过原位邻近结扎测定（PLA）和三个腔室（内皮细胞，血管周围肿瘤细胞和普通肿瘤）中的NRP1蛋白表达来确定顺式（在同一细胞上）和反式（在细胞之间）配置中的VEGFR2 / NRP1复合物形成细胞表达）通过免疫荧光染色确定。探索了NRP1在血管周肿瘤细胞中的表达，作为两个RCC队列中RCC存活的标志物。使用公开的透明细胞RCC（ccRCC）基因表达数据集进一步验证了结果。我们发现在75％的患者样本中检测到VEGFR2 / NRP1反式复合物。反式VEGFR2 / NRP1复合物或血管周围NRP1表达的存在与肿瘤血管密度和大小的减少有关。探索NRP1作为RCC预后的生物标志物时，在两个独立的队列中，血管周NRP1和普通肿瘤细胞NRP1蛋白的表达与存活率提高相关，并且使用可公开获得的ccRCC基因表达数据集，在mRNA水平上也获得了显着的结果。在多变量分析中，只有血管周围的NRP1表达仍然显着。我们的工作表明，血管周NRP1表达是RCC患者存活率提高的独立标志，并且通过与肿瘤内皮中的VEGFR2反式形成复合物来减少肿瘤血管形成。©2019作者。John Wiley＆Sons Ltd代表大不列颠及爱尔兰病理学会出版的《病理学杂志》。并且使用可公开获得的ccRCC基因表达数据集，在mRNA水平上也获得了显着结果。在多变量分析中，只有血管周围的NRP1表达仍然显着。我们的工作表明，血管周NRP1表达是RCC患者存活率提高的独立标志，并且通过与肿瘤内皮中的VEGFR2反式形成复合物来减少肿瘤血管形成。©2019作者。John Wiley＆Sons Ltd代表大不列颠及爱尔兰病理学会出版的《病理学杂志》。并且使用可公开获得的ccRCC基因表达数据集，在mRNA水平上也获得了显着的结果。在多变量分析中，只有血管周围的NRP1表达保持显着。我们的工作表明，血管周NRP1表达是RCC患者存活率提高的独立标志，并且通过与肿瘤内皮中的VEGFR2反式形成复合物来减少肿瘤血管形成。©2019作者。John Wiley＆Sons Ltd代表大不列颠及爱尔兰病理学会出版的《病理学杂志》。并通过在肿瘤内皮中与VEGFR2反式形成复合物来减少肿瘤血管生成。©2019作者。John Wiley＆Sons Ltd代表大不列颠及爱尔兰病理学会出版的《病理学杂志》。并通过在肿瘤内皮中与VEGFR2反式形成复合物来减少肿瘤血管生成。©2019作者。John Wiley＆Sons Ltd代表大不列颠及爱尔兰病理学会出版的《病理学杂志》。