Restoration of Tumor Suppression Activity in Malignant Melanoma

描述（申请人提供）：我们实验室发现S100B蛋白在原发性恶性黑色素瘤中与野生型p53结合，解离p53四聚体，下调p53依赖性肿瘤抑制；因此，开发S100B-p53相互作用的抑制剂来恢复野生型p53在这种癌症中的活性是很重要的。作为原理证明，我们还证明了用小干扰反义RNA （siRNASIOOB）抑制S100B可以恢复原发恶性黑色素瘤中野生型p53肿瘤抑制活性。因此，我们假设可以合理设计低分子量化合物，以高亲和力结合S100B上明确的p53结合位点，抑制S100B-p53相互作用。这一假设将在拟议的研究中进一步得到验证，通过发现和合成这些具有以下具体目标的分子。在Aim 1中，计算机辅助药物设计（CADD），结合高通量/自动化核磁共振，热力学结合和p53功能分析将用于发现结合S100B并抑制S100B-p53相互作用的先导化合物。在Aim 2中，s100b药物配合物的3D结构将使用核磁共振波谱和/或x射线晶体学来确定。这种结构的确定已经在进行中。在Aim 3中，将通过化学修饰来优化抑制S100B-p53相互作用的先导化合物。有机合成将以3D结构数据（来自Aim 2）和CADD导联优化方法为指导。新类似物的测试将使用现有的热力学结合和生物分析（如目标1）进行。利用这一策略，我们的目标是发现/合成结合S100B并恢复恶性黑色素瘤中p53活性的新化合物。在未来，最有希望的化合物将在动物模型中检查治疗黑色素瘤的功效。这些抑制剂可能对其他S100B水平升高和野生型p53的癌症有治疗价值，如星形细胞瘤、肾肿瘤和白血病患者的恶性成熟t细胞。

DESCRIPTION (provided by applicant): Our lab has shown that the S100B protein binds to wild-type p53 in primary malignant melanoma, dissociates the p53 tetramer, and down-regulates p53-dependent tumor suppression; therefore, it is important to develop inhibitors of the S100B-p53 interaction to restore wild-type p53 activity in this cancer. As a proof of principle, we have also demonstrated that inhibiting S100B with small interfering antisense RNA (siRNASIOOB) restores wild-type p53 tumor suppressor activity in primary malignant melanoma. Accordingly, we hypothesize that low molecular weight compounds can be rationally designed to bind the well-defined p53 binding site on S100B with high affinity and inhibit the S100B-p53 interaction. This hypothesis will be tested further in the proposed study, via discovery and synthesis of such molecules with the following specific aims. In Aim 1, computer aided drug design (CADD), combined with high- throughput/automated NMR, thermodynamic binding and p53 functional assays will be used to discover lead compounds that bind S100B and inhibit the S100B-p53 interaction. In Aim 2, 3D structures of S100B-drug complexes will be determined using NMR spectroscopy and/or X-ray crystallography. Such structure determinations are already underway. In Aim 3, optimization of lead compounds that inhibit the S100B-p53 interaction will be performed via chemical modifications. Organic syntheses will be guided by 3D structural data (from Aim 2) and CADD lead optimization approaches. Testing of new analogues will be performed using existing thermodynamic binding and biological assays (as in Aim 1). With this strategy, it is our aim to discover/synthesize new compounds that bind S100B and restore p53 activity in malignant melanoma. In the future, the most promising compounds will be examined for efficacy in treating melanoma in animal models. Inhibitors such as these will likely have therapeutic value for treatment of other cancers that have elevated S100B levels and wild-type p53 such as astrocytomas, renal tumors and malignant mature T-cells in leukemia patients.