Molecular targets of hypoxia in signaling cancer

描述（由申请人提供）：有令人信服的证据表明，肿瘤血管生成是肿瘤生长超过最小尺寸所必需的。肿瘤细胞分泌的血管生成肽诱导肿瘤内新血管的生长。这些血管生成因子的产生的刺激是肿瘤缺氧，并且它通过特定癌基因和肿瘤抑制基因的突变而加重。缺氧诱导转录因子（HIF）是细胞对缺氧反应的中心调节因子，也是几种血管生成因子的上游激活因子。 其中HIF失调的原型病症是Von HippeI-Lindau（VHL）病。VHL功能的丧失直接稳定HIF，并通过促进肿瘤细胞增殖导致恶性表型的基因的反式激活。 HIF可能是VHL+/+和VHL-/-实体瘤生长所必需的。因此，可以想象，抑制HIF而不是分别靶向每种特定的血管生成因子，可能是抑制和/或预防肿瘤形成的有力策略。 在目标1中，我们提出从肿瘤细胞系中产生稳定的和可诱导的克隆，其中HIF活性通过短干扰RNA的表达被抑制。作为第二个策略（目标1和2），我们将使用我们在高通量筛选中发现的小分子HIF抑制剂。我们将确定抑制的分子机制和这些化合物对VHL+/+和VHL-/-肿瘤细胞系的总体促血管生成特征的影响。药理学指导的给药方案将用于研究抑制剂对小鼠异种移植和自发发展肿瘤的影响。这些研究将测试HIF是否是肿瘤血管生成所必需的。在这些原理验证实验过程中产生的试剂可以为抗癌药物开发提供直接基础。

DESCRIPTION (provided by applicant): There is compelling evidence that tumor angiogenesis is necessary for a tumor to grow beyond a minimal size. Tumor cell secreted angiogenic peptides induce the growth of new blood vessels into tumors. The stimulus for the production of these angiogenic factors is tumor hypoxia and it is accentuated by mutations in specific oncogenes and tumor suppressor genes. The Hypoxia Inducible transcription Factor (HIF) is a central regulator of this cellular response to hypoxia and an upstream activator of several angiogenic factors. A prototypic disorder in which HIF is deregulated is Von HippeI-Lindau (VHL) disease. Loss-of-VHL function directly stabilizes HIF and results in the transactivation of genes contributing to the malignant phenotype by promoting tumor cell proliferation. HIF may be necessary for growth of VHL+/+ and VHL-/- solid tumors. It is, therefore, conceivable that inhibiting HIF, instead of targeting each specific angiogenic factor separately, may be a powerful strategy to inhibit and/or prevent tumor formation. In Aim 1 we propose to generate stable and inducible clones derived from tumor cell lines, in which HIF activity is inhibited through expression of short interfering RNA. As a second strategy (Aims 1 and 2) we will use small molecule HIF inhibitors that we discovered in a high throughput screen. We will determine the molecular mechanism of inhibition and the effect of these compounds on the overall pro-angiogenic profile of VHL+/+ and VHL-/- tumor cell lines. Pharmacologically guided dosing regimens will be used to study the effect of inhibitors on xenografted and spontaneously developing tumors in mice. These studies will test whether HIF is necessary for tumor angiogenesis. Reagents generated at the course of these proof-of-principle experiments may provide the direct basis for anti-cancer drug development.