Biophysics of cancer: modelling and assessing physical resistance to therapy

本提案将使用器官芯片技术和原子力显微镜（AFM）来研究体外培养的胰腺癌微肿瘤在生理相关流动条件下的力学特性，以及这些肿瘤的机械刚度与耐药性的关系。实体瘤在体内形成致密、坚硬的组织区域，类似于疤痕组织。在肿瘤内部，存在一个复杂的生物物理条件微环境，它决定了疾病的进展，并为药物递送提供了物理障碍。胰腺癌的特点是密集的纤维状肿瘤团块，其中固体应力和液压导致血管塌陷，血管是药物输送的主要途径。此外，体内的高压会阻碍药物进入肿瘤。然而，尽管有这些至关重要的物理因素，大多数药物的体外测试都是针对完全忽略这些生物物理参数的细胞培养模型进行的。我们将利用微流控液滴发生器将胰腺肿瘤细胞系植入规定尺寸（500微米）的微凝胶中，并在类似于细胞在体内所经历的连续流动条件下培养，从而创造出胰腺癌的微肿瘤，为它们提供一个更自然的生长环境。我们将使用AFM来评估这些肿瘤在细胞增殖和将基质硬化成分沉积到微环境中时的机械刚度，并将它们与在静态井中生长的相同肿瘤进行比较，以确定水力线索在微环境发育中的作用和重要性。然后，我们将使用该平台来研究这些微肿瘤的机械特性与它们对药物穿透其结构的抵抗力之间的关键关系。我们预计，微肿瘤越硬，药物摄取就越少。然后，这将与微肿瘤的生存能力相关联，以全面了解肿瘤的发展和对药物的耐药性。最后，利用我们的创新方法，我们将研究通过将微肿瘤暴露于主动分解僵硬基质并可能增加药物渗透的药物来促进实体肿瘤药物摄取的新途径。胰腺癌仍然是最致命的现代癌症之一，93%的确诊患者在5年内死亡。目前治疗胰腺癌的药物大多无效。只有通过改进我们的体外疾病模型，准确地模拟耐药性模式，我们才能改善治疗和患者的预后。这一建议侧重于胰腺癌，但将适用于所有实体肿瘤。

This proposal will use organ-on-chip technology and Atomic Force Microscopy (AFM) to investigate the mechanical properties of in vitro cultured microtumours of pancreatic cancer as they develop under physiologically relevant flow conditions and how the mechanical stiffness of these tumours relates to drug resistance. Solid tumours develop in the body to form areas of dense, rigid tissue, similar to that of scar tissue. Within tumours, there is a complex microenvironment of biophysical conditions that determine the progression of the disease and provide physical barriers to drug delivery. Pancreatic cancer is hallmarked by a dense, fibrous tumour mass in which solid stress and hydraulic pressure cause the collapse of blood vessels, the main route for drug delivery. In addition, the high internal pressures act against the movement of drugs into the tumour mass. Yet despite these critically important physical factors, most in vitro testing of drugs is done against cell culture models that neglect these biophysical parameters entirely. This proposal we will create microtumours of pancreatic cancer by using microfluidic droplet generators to seed pancreatic tumour cell lines into microgels of defined size (500 um) and culture them under continuous flow conditions similar to what the cells would experience in the body, giving them a more natural environment in which to develop. We will use AFM to assess the mechanical rigidity of these tumours as cells proliferate and deposit matrix stiffening components into their microenvironment and compare them to the same tumours grown in static wells in order to determine the role and importance of hydraulic cues in microenvironment development. We will then use the platform to investigate the crucial relationship between the mechanical properties of these microtumours and their resistance to the penetration of drugs into their structure. We expect that the stiffer the microtumour, the less drug uptake will be observed. This will then be correlated to microtumour viability for a complete picture of tumour development and resistance to drug delivery. Lastly, using our innovative approach, we will investigate new routes to facilitate drug uptake in solid tumours by exposing microtumours to agents that actively break down the stiff matrix and potentially increase drug penetration. Pancreatic cancer remains one of the deadliest modern-day cancers, with 93% of those being diagnosed dying within 5 years. Current drug treatments for pancreatic cancer are largely ineffective. Only by improving our in vitro models of disease, in which we accurately model the mode of drug resistance, can we improve treatments and patient outcomes. This proposal focussing on pancreatic cancer but will be applicable to all solid tumours.