Evaluation of the molecular pathogenesis of adrenocortical tumors by functional genomics

肾上腺皮质肿瘤包括良性腺瘤和恶性癌。肾上腺皮质腺瘤是最常见的人类肿瘤之一，可以是激素活跃或内分泌沉默。另一方面，肾上腺皮质癌是一种罕见的癌症，预后很差，治疗选择有限。尽管最近取得了进展，但自主类固醇分泌（如肾上腺库欣综合征）和肾上腺皮质肿瘤发生的致病机制在很大程度上仍然不清楚。利用单核苷酸多态性（SNP）阵列和下一代外显子组测序，我们已经确定了影响基因或途径的关键改变，这些改变可能代表自主类固醇分泌（即PRKACA基因的体细胞突变）和早期肿瘤发生（即Notch信号通路的激活）的潜在驱动因素。该计划的目的是确定可能参与肾上腺皮质肿瘤发病机制的其他相关基因组变异和分子改变。因此，我们将扩展我们的研究，利用现代遗传分析的组合，如全基因组测序和rna测序。在研究的第一部分，我们将研究快速冷冻的肾上腺腺瘤样本，其中外显子组测序未发现任何“驱动”突变，以及早期肿瘤阶段的肾上腺皮质癌。因此，我们的目标是调查到目前为止尚未探索的遗传改变（例如在基因调控区域）及其与基因表达和临床表型变化的因果关系。在第二部分中，我们将首次在正常肾上腺和肾上腺皮质肿瘤的单细胞水平上进行分子分析。这种新方法将允许研究细胞亚群，肿瘤内分子异质性和克隆复杂性，以获得分子和细胞结构的基本新见解。这将导致更好地理解自主类固醇分泌和早期肾上腺皮质肿瘤的发生，以促进在未来的发展新的治疗方案。

Adrenocortical tumors comprise benign adenomas and malignant carcinomas. Adrenocortical adenomas are among the most prevalent human neoplasias and can be hormonally active or endocrinologically silent. On the other side, adrenocortical carcinoma is a rare cancer with very poor prognosis and limited treatment options. Despite recent advances, the pathogenic mechanisms underlying autonomous steroid secretion (e.g. adrenal Cushing Syndrome) and adrenocortical tumorigenesis still remain largely obscure. Using single nucleotide polymorphism (SNP) arrays and next generation exome-sequencing we have identified key alterations affecting genes or pathways that could represent potential drivers for autonomous steroid secretion (i.e. somatic mutations in the PRKACA gene) and early tumorigenesis (i.e. activation of the Notch signalling pathway). The aim of the proposed project is to identify additional relevant genomic variants and molecular alterations that may be involved in the pathogenesis of adrenocortical neoplasias. Therefore, we will extend our research, utilizing now a combination of modern genetic analyses such as whole-genome sequencing and RNA-sequencing. In the first part of the study, we will investigate snap-frozen adrenal adenoma samples, in which exome sequencing did not identify any "Driver" mutation, as well as adrenocortical carcinomas in early tumor stages. We thereby aim to investigate so far unexplored genetic alterations (for instance in gene-regulatory regions) and their causal link with changes in gene expression and clinical phenotype. In the second part, we will perform for the first time molecular analysis at the single-cell level in both normal adrenal glands and adrenocortical tumors. This novel approach will allow investigating cellular subpopulations, intra-tumoral molecular heterogeneity and clonal complexity to gain fundamental new insights in the molecular and cellular architecture. This will lead to a better understanding of autonomous steroid secretion and early adrenocortical tumorigenesis in order to facilitate in the future the development new therapeutic options.