Molecular and spatial dissection of endothelial cell heterogeneity in clear cell renal cell carcinoma

透明细胞肾细胞癌内皮细胞异质性的分子和空间解剖

• 批准号: 497667643
• 负责人: Professor Dr. Michael Hölzel
• 金额: --
• 依托单位: Institut für Pathologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/497667643?language=en
• 关键词: Molecular; spatial; dissection; endothelial; cell

Endothelial cells (ECs) line the inner wall of blood vessels fulfilling different tasks in our organs. ECs are characterized by remarkable phenotypic and functional heterogeneity. However, only the recent advances in single-cell RNA sequencing (scRNA-seq) enabled researchers to define the molecular heterogeneity of ECs in a truly comprehensive manner. Also, scRNA-seq revealed novel principles how ECs respond to stresses and injuries being relevant for many major diseases. As tumour growth is dependent on constant nutrient and oxygen supply, de novo blood vessel formation (neoangiogenesis) is a hallmark of cancer. For many cancer types, anti-angiogenic therapy that blocks vascular endothelial growth factor (VEGF) signalling was less effective than hoped for, but renal cancers proved to be quite responsive to tyrosine kinase inhibitors (TKIs) targeting the VEGF receptor (VEGFR). This is in line with the fact that renal cancers are highly vascularized and harbour mutations that drive neoangiogenesis. Clear cell renal cell carcinoma (ccRCC) represents the most frequent subtype. VEGFR TKIs are the current mainstay of ccRCC treatment (advanced stage) combined with immune checkpoint blockade, though efficacy and durability are variable. In this context, the precise role of ECs in primary or acquired resistance to VEGFR TKIs treatment is poorly understood. Thus, more profound molecular and mechanistic insights into EC heterogeneity of ccRCCs are critically needed. Proliferation and sprouting of vessels within and around tumours are typical histological features of neoangiogenesis. Most studies in the field focused either on microvasculature density or on tumour cell characteristics like mutations, but our understanding of the complex interplay between ECs and ccRCC tumour cells lacks far behind. Moreover, pathologists appreciate that ccRCCs are characterized by very different blood vessel architectures, which can be roughly classified as glomeruloid, low branching, high branching and sinusoidal-anastomosing. As a matter of fact, it is unknown whether these distinct vascular patterns actually have distinct molecular correlates of ECs or not, and whether these phenotypes are intrinsically driven by ECs, instructed by the surrounding tumour cells or both. Essentially, these are the question that we aim to address in our project. For this, we will isolate ECs and perform scRNA-seq in order to explore the phenotypic space ECs in human ccRCCs. Further, we will link novel EC phenotypes to the genomic and spatial context of ccRCCs by whole-exome sequencing and high-plex immunofluorescence. Lastly, we will employ an innovative patient-derived tumour fragment platform and EC co-culture assays to study how phenotypic diversity of ECs from ccRCCs is linked to functional diversity. We believe that we will establish novel concepts of EC heterogeneity in ccRCCs and delineate new avenues how EC phenotypes may guide the stratification for VEGFR TKI-based therapies.

内皮细胞（EC）排列在血管内壁，在我们的器官中执行不同的任务。内皮细胞具有显著的表型和功能异质性。然而，只有单细胞RNA测序（scRNA-seq）的最新进展才能使研究人员以真正全面的方式定义EC的分子异质性。此外，scRNA-seq揭示了EC如何应对与许多重大疾病相关的压力和损伤的新原理。由于肿瘤生长依赖于持续的营养和氧气供应，新生血管形成（新血管生成）是癌症的标志。对于许多癌症类型，阻断血管内皮生长因子（VEGF）信号传导的抗血管生成治疗不如预期有效，但肾癌被证明对靶向VEGF受体（VEGFR）的酪氨酸激酶抑制剂（TKI）非常敏感。这与肾癌是高度血管化的并且具有驱动新血管生成的突变的事实一致。透明细胞肾细胞癌（ccRCC）是最常见的亚型。VEGFR TKI是目前ccRCC治疗（晚期）联合免疫检查点阻断的主要药物，但疗效和持久性各不相同。在这种情况下，EC在VEGFR TKI治疗的原发性或获得性耐药中的确切作用尚不清楚。因此，迫切需要对ccRCC的EC异质性的更深刻的分子和机制见解。肿瘤内和周围血管的增殖和出芽是新血管生成的典型组织学特征。该领域的大多数研究都集中在微血管密度或肿瘤细胞特征（如突变）上，但我们对EC和ccRCC肿瘤细胞之间复杂相互作用的理解远远落后。此外，病理学家认识到，ccRCC的特征在于非常不同的血管结构，其可以大致分为肾小球样、低分支、高分支和窦状血管闭塞。事实上，目前尚不清楚这些不同的血管模式是否实际上具有不同的EC分子相关性，以及这些表型是否由EC内在驱动，由周围的肿瘤细胞指示或两者兼而有之。从本质上讲，这些都是我们在项目中要解决的问题。为此，我们将分离EC并进行scRNA-seq，以探索人ccRCC中的表型空间EC。此外，我们将通过全外显子组测序和高重免疫荧光将新的EC表型与ccRCC的基因组和空间背景联系起来。最后，我们将采用创新的患者源性肿瘤片段平台和EC共培养试验来研究来自ccRCC的EC的表型多样性如何与功能多样性相关联。我们相信，我们将在ccRCC中建立EC异质性的新概念，并描绘EC表型如何指导基于VEGFR TKI的治疗分层的新途径。