Restoration of Tumor Suppression Activity in Malignant Melanoma

描述（由申请人提供）：我们的实验室已经证明，S100 B蛋白与原发性恶性黑色素瘤中的野生型p53结合，解离p53四聚体，并下调p53依赖性肿瘤抑制;因此，开发S100 B-p53相互作用的抑制剂以恢复这种癌症中的野生型p53活性非常重要。作为原理的证明，我们还证明了用小干扰反义RNA（siRNASIOOB）抑制S100 B可以恢复原发性恶性黑色素瘤中野生型p53肿瘤抑制活性。因此，我们假设低分子量化合物可以被合理地设计为以高亲和力结合S100 B上明确定义的p53结合位点并抑制S100 B-p53相互作用。这一假设将在拟议的研究中进一步测试，通过发现和合成具有以下特定目标的此类分子。在目标1中，计算机辅助药物设计（CADD）结合高通量/自动化NMR、热力学结合和p53功能测定将用于发现结合S100 B并抑制S100 B-p53相互作用的先导化合物。在目标2中，将使用NMR光谱学和/或X射线晶体学确定S100 B-药物复合物的3D结构。这种结构的确定已经在进行中。在目标3中，将通过化学修饰进行抑制S100 B-p53相互作用的先导化合物的优化。有机合成将由3D结构数据（来自Aim 2）和CADD铅优化方法指导。新类似物的检测将使用现有的热力学结合和生物学试验进行（如目标1所示）。通过这种策略，我们的目标是发现/合成结合S100 B并恢复恶性黑色素瘤中p53活性的新化合物。在未来，最有前途的化合物将在动物模型中检查治疗黑色素瘤的疗效。诸如这些的抑制剂将可能对具有升高的S100 B水平和野生型p53的其他癌症（诸如星形细胞瘤、肾肿瘤和白血病患者中的恶性成熟T细胞）的治疗具有治疗价值。

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.