Predicting Radiation Response by Tumor pO2

描述（由申请人提供）：本申请的基础来自新的数据，这些数据表明中等氧浓度（约1%）的细胞主导肿瘤的治疗反应和生物学的假设。 我们的假设起源于利用定量方法确定组织缺氧的体内研究。 本实验室开发的该方法测量2-硝基咪唑缺氧标记物EF 5（2-（2-硝基-1H-咪唑-1-基）-N-（2，2，3，3，3-五氟丙基）乙酰胺）的结合。 使用荧光单克隆抗体和校准至实际细胞pO 2的生物测量的荧光标度测量结合的EF 5加合物。 使用该方法预测迄今为止研究的两种类型的个体大鼠肿瘤（9 L胶质瘤和Morris 7777肝癌）的辐射反应。 已经提出了两种用于产生肿瘤缺氧的模型：在第一种模型中，血流处于稳定状态，导致扩散限制缺氧，而在第二种模型中，血流循环开和关，导致灌注限制缺氧。 这些模型中的哪一个在啮齿动物或人类肿瘤中最相关，仍然是一个重要的未解决的问题。 尽管具有许多生物学和治疗分支，但以前仅通过间接方法解决。 由于这两种模型的缺氧预测形成不同的模式的缺氧相对于肿瘤血管系统，我们提出了一个直接调查这个问题，通过详细的三维图像分析，使用皮下和原位的裸鼠人异种移植瘤。 为了支持体内图像分析研究，将在体外对稳态与循环缺氧的生化和分子后果进行定量评估。 这些研究将强调那些已知被肿瘤微环境修饰的分子标志物，目前正在考虑作为临床预后标志物（例如HIF-1 α、碳酸酐酶IX、Glut-1和VEGF）。 人体研究继续支持缺氧在限制治疗反应方面的重要性-因此需要新的致敏方法。 Sonus公司（西雅图）生产的一种新的全氟化学乳剂（PFC）将用于确定缺氧肿瘤细胞（中度和重度缺氧）是否可以作为治疗靶点。 该乳液（DDFP）具有在28度以上形成稳定的亚微米尺寸气泡的显著特性。 DDFP气泡，像以前的液体PFC乳液，作为高容量的氧载体，但不像所有以前的配方，这样做在低得多的浓度。 DDFP因此可能是第一个PFC乳剂实用和安全的多组分临床方案。

DESCRIPTION (provided by applicant): The basis of this application arises from new data suggesting the hypothesis that cells at intermediate oxygen concentrations (centered around approximately 1%) dominate the therapeutic response and biology of tumors. Our hypothesis originated from in vivo studies utilizing a quantitative method for determining tissue hypoxia. This method, developed in our laboratory, measures binding of the 2-nitroimidazole hypoxia marker EF5 (2-(2-nitro-1H-imidazol-1-yl)-N- (2,2,3,3,3-pentafluoropropyl)acetamide). The bound EF5 adducts are measured using fluorescent monoclonal antibodies and a fluorescence scale calibrated to biological measures of actual cellular pO2. Use of this method predicts the radiation response in individual rat tumors of two types studied to date (9L glioma and Morris 7777 hepatoma). There have been two models proposed for the production of tumor hypoxia: in the first, blood flow is in a steady state leading to diffusion limited hypoxia whereas in the second, blood flow cycles on and off leading to perfusion limited hypoxia. Which of these models is most relevant, in either rodent or human tumors, remains an important unresolved question. Despite having many biological and therapeutic ramifications, it has previously been addressed solely by indirect methods. Since the two models of hypoxia are predicted to form different patterns of hypoxia with respect to the tumor vasculature, we propose a direct investigation of this question by detailed 3-dimensional image analysis, using subcutaneous and orthotopic human xenograft tumors in nude rats. To support the in vivo image analysis studies, quantitative assessments of the biochemical and molecular consequences of steady state vs. cycling hypoxia will be made in vitro. These studies will emphasize those molecular markers known to be modified by the tumor microenvironment and presently under consideration as clinical prognostic markers (e.g. HIF-1alpha, Carbonic Anhydrase IX, Glut-1 and VEGF). Studies in humans continue to support the importance of hypoxia in limiting treatment response - thus new sensitization approaches are required. A new perfluorochemical emulsion (PFC) made by the Sonus Company (Seattle) will be employed to determine whether hypoxic tumor cells (both intermediate and severe hypoxia) can be targeted therapeutically. This emulsion (DDFP) has the remarkable property of forming stable, sub-micron sized gas bubbles above 28 degrees. The DDFP bubbles, like former liquid PFC emulsions, serve as high-capacity oxygen carriers but, unlike all previous formulations, do so at much lower concentrations. DDFP may thus be the first PFC emulsion practical and safe for use in multifraction clinical regimens.