Using patient-led genetics to identify new therapeutic targets in metastatic cholangiocarcinoma

胆管细胞癌(CCA)包括一组不同种类的恶性肿瘤，可出现在胆道树的任何一点。发病率(约5：100,000)在全球范围内呈上升趋势，CCA已成为第二大最常见的原发性肝肿瘤，约占所有胃肠道肿瘤的3%。值得注意的是，在过去20年中，欧洲登记的死亡人数增加了37%，这使CCA成为主要的卫生、社会和经济负担。CCA通常在早期没有症状，通常在晚期被诊断出来，那时大多数患者都有转移性疾病。这种情况极大地损害了主要以手术或肝移植为基础的潜在治疗选择，并明显影响到世界各地的所有卫生系统。此外，肿瘤复发的高风险和CCA化疗耐药性的增加导致预后较差。一线化疗包括吉西他滨和顺铂的组合，这种药物是姑息性的，仅能增加患者12个月的总存活率。CCA的发病机制目前尚不清楚。在分子水平上，CCA是一种遗传异质性疾病，虽然已经发现了少量的驱动程序突变，但三分之一的患者不包含可治疗的突变，对于其余三分之二的患者来说，针对这些突变的靶向治疗效果有限。这项拟议的工作将研究转移性CCA的分子基础，并确定CCA的遗传多样性如何塑造不同的肿瘤微环境。使用整个外显子组测序候选“转移驱动因素”突变的CCA患者来源的循环肿瘤细胞(CTC)将被识别。将实施一种创新的体内CRISPR筛查方法，以产生含有小鼠“转移驱动因素”突变的原发肿瘤，并将评估这些驱动因素在体内启动CCA转移的潜力。我们将在这里利用这些信息来确定不同的突变如何影响癌细胞和肿瘤微环境之间的相互作用，并最终允许肿瘤发生转移。这项工作将极大地增加我们对CCA功能遗传学的理解，以及可能为具有不同基因组图谱的转移性CCA的未来治疗开发识别新的靶向途径。此外，它有望确定可在其他癌症中测试的广泛适用的转移原则。最终，通过了解基因变化如何相互作用来塑造肿瘤的结构，我们将更好地调节这些过程以获得治疗益处。

Cholangiocarcinoma (CCA) includes a heterogeneous group of malignancies that can emerge at every point of the biliary tree. Incidence (~5:100,000) is rising worldwide and CCA already represents the second most frequent primary liver tumour and ~3% of all gastrointestinal cancers. Noteworthy, a 37% increase in deaths were registered in Europe in the past two decades, which makes CCA a major health, social and economic burden. CCA is generally asymptomatic in early stages and is commonly diagnosed in advanced phases, when the majority of patients have metastatic disease. This circumstance extremely compromises the potential curative options mainly based on surgery or liver transplantation and clearly impacts on all the health systems worldwide. Moreover, the high risk of tumour recurrence and the elevated chemoresistance of CCAs contribute to poor prognosis. The first line chemotherapy includes the combination of gemcitabine and cisplatin, which is palliative and solely increases patients overall survival in 12 months. The etiopathogenesis of CCA remains largely unknown. At the molecular level, CCA is a genetically heterogeneous disease and whilst a small number of driver-mutations have been found, one-third of patients do not contain therapeutically actionable mutations and for the remaining two-thirds that do, targeted therapies against these mutations have limited efficacy. The proposed work will examine the molecular basis of metastatic CCA and determine how genetic diversity in CCA sculpts a diverse tumour microenvironment. Using whole exome sequencing candidate "metastatic driver" mutations in CCA patient-derived circulating tumour cells (CTC) will be identified. An innovative in vivo CRISPR screening method to generate primary tumours containing mutations in "metastatic drivers" in the mouse will be performed, and the potential of these drivers to initiate CCA metastasis in vivo will be assessed. We will use the information here to identify how distinct mutations affect the interactions between cancer cells and the tumour microenvironment, and ultimately allow a tumour to become permissive to metastasis. This work should substantially increase our understanding of the functional genetics in CCA, as well as the likely identification of novel target pathways for future therapeutic development in metastatic CCA with diverse genomic profiles. Furthermore, it is expected to identify broadly applicable principles of metastasis that can be tested in other cancers. Ultimately, by understanding how genetic changes interact to shape the architecture of a tumour, we will be better placed to modulate these processes for therapeutic benefit.