Microelectrode oxygenation control of tumor necrosis

描述(由申请人提供)：不同种类的氧气输送到组织中在许多生物过程和许多疾病的治疗中起着至关重要的作用。这项建议描述了使用一种新型的氧气微电极装置来测量局部氧气输送对肿瘤坏死的影响。其具体目标是：1)开发一种氧气微梯度芯片，能够以微尺度的时空分辨率测量和控制组织中的氧气环境；2)精确地将氧气输送到肿瘤组织，测量单个细胞的死亡，并确定低氧导致肿瘤坏死的程度；以及3)证明HIF1-α反应对于缺氧肿瘤组织中的细胞生存至关重要。肿瘤的缺氧和坏死都是由氧气供应不足引起的，都与患者预后不良有关。缺氧诱导因子1-α(HIF1-α)是一种很有前途的治疗靶点，因为它可以促进细胞在缺氧条件下的存活，从而可能导致肿瘤的生长。目前还没有一种技术能够以细胞分辨率控制组织的氧气微环境。该装置将产生稳定的微梯度气体剖面，以响应瞬变实验条件。该设备将用于广泛的组织和应用，包括组织工程和干细胞分化。在这项提议中，氧气将被输送到含有HIF1-a和无效的体外肿瘤中，同时保留其他浓度梯度(葡萄糖、酸性废物等)。通过测量细胞死亡的程度，氧梯度对细胞存活的影响将被独立地识别出来。许多有希望的治疗药物正在被设计成针对肿瘤独特的微环境。在这里，精确控制的实验将评估同时针对缺氧和HIF1-α的治疗潜力。综上所述，微电极将被用于向三维肿瘤组织输送氧气，以测量氧气对细胞存活和HIF1-α表达的影响。

DESCRIPTION (provided by applicant): Heterogeneous delivery of oxygen to tissues plays a crucial role in many biological processes and the treatment of many diseases. This proposal describes the use of a novel oxygen microelectrode device to measure the effect of localized oxygen delivery on tumor necrosis. The specific goals are to: 1) develop an oxygen microgradient chip that allows measurement and control of the oxygen environment in a tissue with microscale spatio-temporal resolution; 2) precisely deliver oxygen to tumor tissue, measure individual cell death, and determine the extent that poor oxygenation causes tumor necrosis; and 3) demonstrate that a HIF1-alpha response is critical for cell survival in hypoxic tumor tissue. Tumor hypoxia and necrosis are both caused by poor oxygen supply and are both correlated with poor patient prognosis. Hypoxia inducible factor1-alpha (HIF1-alpha) is a promising therapeutic target because it promotes cell survival in hypoxic conditions, which may lead to tumor growth. No technology currently exists that allows control of the oxygen microenvironment of tissues with cellular resolution. The proposed device will generate stable microgradient gas profiles that are responsive to transient experimental conditions. This device will be useful with a wide range of tissues and applications including tissue engineering and stem cell differentiation. In this proposal, oxygen will be delivered to HIF1-a-containing and null in vitro tumors while preserving other concentration gradients (glucose, acidic waste products, etc.). By measuring the extent of cell death, the effect of oxygen gradients on cell survival will be independently discerned. Many promising therapeutics are being designed to target the unique microenvironments of tumors. Here, precisely controlled experiments will evaluate the therapeutic potential of targeting both hypoxia and HIF1-alpha. In summary, microelectrodes will be used to deliver oxygen to three-dimensional tumor tissue to measure the effect of oxygen on cell survival and HIF1-alpha expression.