Growing with an 'advantage': Dissecting the links between embryonic cell competition and tumourigenesis

带着“优势”成长：剖析胚胎细胞竞争与肿瘤发生之间的联系

• 批准号: 2740717
• 金额: --
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2740717
• 关键词: Growing; advantage; Dissecting; links; between

A key mechanism underlying tumour initiation involves the acquisition of a selective advantage by early malignant cells, which outcompete and eliminate neighbouring non-transformed cells. This 'super-competitive' behaviour is often linked to increased activity of the oncogene MYCN, which is also associated with neuroblastoma, the most common extra-cranial solid tumour in infants. Neuroblastoma tumours arise during embryonic development, typically at the trunk level, within a multipotent cell population - the neural crest (NC) - that gives rise to the adrenal gland and sympathetic ganglia. We recently established a tractable system that facilitates the temporal dissection of MYCN-driven neuroblastoma initiation. This involves the stepwise differentiation of human embryonic stem cells (hESCs) toward trunk NC and its derivatives (Frith et al. 2018; Frith et al. 2019). To mimic MYCN hyperactivity, we engineered hESCs to overexpress MYCN simultaneously with the fluorescent reporter in a Doxycycline (Dox)-inducible manner. Our preliminary data shows that Dox-inducible elevation of MYCN activity promotes hallmarks of tumourigenesis such as impaired differentiation and increased proliferation.This PhD project aims to understand how MYCN promotes tumour initiation in trunk NC cells and test the hypothesis that this occurs via the selection of super-competitive cells. We will first examine the mode of competitive cell interactions between MYCN-overexpressing cells and their normal isogenic counterparts. To this end we will monitor interactions of fluorescently-labelled wild-type and MYCN-overexpressing cells in mosaic cultures using time-lapse imaging at different time points of NC differentiation (Price et al. 2021). We will then define the mechanisms underlying the selection of super-competitive cells and elimination of their neighbours using a combination of transcriptome analysis, pharmacological inhibition of candidate signalling pathways and electrophysiology. Finally, we will integrate findings from the above experiments within an established computational framework for cell competition to obtain a quantitative, predictive model for neuroblastoma initiation and its clonal evolution.

肿瘤发生的一个关键机制涉及早期恶性细胞获得选择性优势，这些细胞在竞争中胜出并消灭邻近的非转化细胞。这种“超级竞争”行为通常与癌基因 MYCN 活性增加有关，而癌基因 MYCN 也与神经母细胞瘤（婴儿最常见的颅外实体瘤）有关。神经母细胞瘤发生在胚胎发育过程中，通常发生在躯干水平，位于多能细胞群（神经嵴 (NC)）内，产生肾上腺和交感神经节。我们最近建立了一个易于处理的系统，有助于 MYCN 驱动的神经母细胞瘤起始的时间解剖。这涉及人类胚胎干细胞 (hESC) 向主干 NC 及其衍生物的逐步分化（Frith 等人，2018 年；Frith 等人，2019 年）。为了模拟 MYCN 过度活跃，我们对 hESC 进行了改造，使其以强力霉素 (Dox) 诱导的方式与荧光报告基因同时过表达 MYCN。我们的初步数据表明，Dox 诱导的 MYCN 活性升高会促进肿瘤发生的标志，例如分化受损和增殖增加。这个博士项目旨在了解 MYCN 如何促进躯干 NC 细胞中的肿瘤发生，并测试这一假设，即通过选择具有超强竞争力的细胞。我们将首先检查 MYCN 过表达细胞与其正常同基因对应细胞之间竞争性细胞相互作用的模式。为此，我们将在 NC 分化的不同时间点使用延时成像监测镶嵌培养物中荧光标记的野生型细胞和 MYCN 过表达细胞的相互作用 (Price et al. 2021)。然后，我们将结合转录组分析、候选信号通路的药理学抑制和电生理学来定义选择超级竞争性细胞并消除其邻居的机制。最后，我们将把上述实验的结果整合到已建立的细胞竞争计算框架中，以获得神经母细胞瘤发生及其克隆进化的定量预测模型。