Direct consequences of chromosomal instability in pre-malignant human adenoma

染色体不稳定性（CIN）发生在85%的结直肠癌（CRC）病例中，是CRC的一个重要标志。重要的是，CIN是CRC发展的早期事件，并且腺瘤性结肠息肉病（APC）突变的类型决定了CIN在早期肿瘤阶段的发生。最近的数据表明CIN直接促进细胞生长和细胞转化，并且CIN可能是肿瘤在后期疾病阶段发展转移潜力的先决条件。然而，我们对CIN在早期肿瘤病变和转化的结直肠癌细胞中直接触发的分子后果和下游信号通路的理解是不完整的。使用最先进的三维结肠干细胞培养系统和CRISPR/Cas9介导的基因组编辑，我们的目标是建模并进一步表征CIN在APC突变的人结肠类器官（=腺瘤），AURKA过表达基因组不稳定类器官及其检查点缺陷衍生物中的直接作用。下一代测序（NGS），定量蛋白质组学分析CIN影响的人结肠腺瘤细胞的细胞表面蛋白质组和分泌组将揭示CIN事件及其在人类CRC进展中的作用。此外，考虑到微环境在CRC发生和进展中的关键作用，我们假设CIN的促肿瘤发生作用超出了细胞自主机制，并可能有助于相关成纤维细胞向促肿瘤发生状态的重编程。为了证明这一点，我们将通过磁悬浮技术离体产生含有受CIN +原代结肠成纤维细胞影响的人原代上皮细胞的人类肿瘤。这将使我们能够研究癌前病变的人腺瘤细胞对邻近基质细胞的差异影响。破译人类腺瘤细胞中CIN诱导的信号通路以及早期人类结直肠肿瘤病变及其相关微环境之间的交叉信号传导将揭示癌症预防和治疗癌症的新药物靶点和创新策略。

Chromosomal instability (CIN) occurs in 85% of colorectal cancer (CRC) cases and represents an important CRC hallmark. Importantly, CIN is an early event in CRC development and the type of adenomatous polyposis coli (APC) mutation decides about CIN occurrence at early tumor stages. Recent data suggest CIN directly promotes cell growth and cellular transformation, and CIN might be a prerequisite for tumors to develop a metastatic potential at later disease stages. However, our understanding of the molecular consequences and downstream signaling pathways directly triggered by CIN in early tumor lesions and transformed colorectal cancer cells is incomplete. Using state-of-the-art 3-dimensional colonic stem cell culture systems and CRISPR/Cas9-mediated genome editing, we aim to model and further characterize the direct effects of CIN in APC-mutated human colonic organoids (=adenoma), AURKA overexpressing genomic instable organoids, and their checkpoint-deficient derivatives. Next generation sequencing (NGS), quantitative proteomic analysis of the cell surface proteome and secretome of CIN-affected human colon adenoma cells will shed new light on the CIN event and its role in human CRC progression. Moreover, considering the critical role of the microenvironment in CRC initiation and progression, we hypothesize that a pro-tumorigenic effect of CIN goes beyond cell autonomous mechanisms and likely contributes to the re-programming of associated fibroblasts towards a pro-tumorigenic state. To show this, we will generate human tumoroids ex vivo that contain human primary epithelial cells affected by CIN + primary colonic fibroblasts via magnetic levitation technique. This will allow us to study the differential effects of pre-malignant human adenoma cells suffering from CIN on adjacent stroma cells. Deciphering the CIN-induced signaling pathways in human adenoma cells and the cross-signaling between early human colorectal tumor lesions and their associated microenvironment will reveal novel drug targets and innovative strategies for cancer prevention and curative cancer therapy.