Modelling DNA methylation in the systemic progression of cancer

DNA甲基化是一种可遗传的表观遗传机制，在癌症中经常发生改变，并显示出显著的肿瘤内异质性。它还整合了转录和代谢信号，因此可以稳定/支持转移性转录程序，补充遗传改变的影响。我们研究的BalbNeuT小鼠模型缺乏转移性驱动突变的遗传证据。然而，它显示了原发性肿瘤和转移瘤之间显着的表观遗传差异。因此，它非常适合模拟甲基化进展，解决有关表观遗传改变对转移进展的影响的关键问题。在第一个资助期内，项目A2（斯潘）和A4（斯佩里）密切合作，在BalbNeuT小鼠模型的背景下研究甲基化进展。我们已经监测了系统性进展过程中的DNA甲基化，确定了多种不同的甲基化进展模式，并开发了一种新型的动态横截面模型，可以联合分析甲基化时间以及甲基化和传播之间的因果关系。在这些结果的基础上，我们现在提出开发一种新型的表观遗传进展模型，包括早期病变以及完全生长的原发性肿瘤和肺转移，在代表性的一组25个启动子区域上对它们进行微调，这些区域反复显示甲基化进展，并使用CRISPR/Cas9介导的基因沉默测定来验证模型。此外，我们将使用纵向液体活检来寻找系统性进展早期的进展甲基化。

DNA methylation is a heritable epigenetic mechanism that is frequently altered in cancer and that shows significant intratumoural heterogeneity. It also integrates transcriptional and metabolic signals, and may thus stabilize/support metastatic transcriptional programs complementing the effects of genetic alterations. The BalbNeuT mouse model studied by our consortium lacks genetic evidence for metastatic driver mutations. However, it shows marked epigenetic differences between primary tumours and metastasis. It is therefore ideally suited to model methylation progression addressing key questions regarding the impact of epigenetic alterations on metastatic progression. In the first funding period the projects A2 (Spang) and A4 (Rehli) collaborated intensively to study methylation progression in the context of the BalbNeuT mouse model. We have monitored DNA methylation during systemic progression, have identified multiple distinct patterns of methylation progression, and have developed a new type of dynamic cross sectional models that allows for the joint analysis of methylation timing and the causal relations between methylation and dissemination.Joining forces and building on these results, we now propose to develop a novel type of epigenetic progression models, that include early lesions in addition to full grown primary tumours and lung metastasis, fine tune them on a representative set of 25 promoter regions that recurrently show methylation progression, and validate the model using CRISPR/Cas9 mediated gene silencing assays. Moreover, we will use longitudinal liquid biopsies to search for progressed methylation early in systemic progression.