DEVELOPMENT OF NOVEL CHEMOPRVENTIVE AGENTS

描述（由申请人提供）： 需要新的药剂来实现在开发癌症控制的化学预防方法中日益增长的兴趣和希望的目标（Sporn和Liby，2005，Smith等人，2005; Lippman和Lee，2006;弗朗西斯等人，2006年）。在追求核苷转运抑制剂作为潜在的化学预防剂，我们已经发现，双嘧达莫是一个有效的化学预防剂对12-O-佛波醇-13-肉豆蔻基乙酸酯（TPA）肿瘤促进JB 6 P+细胞。双嘧达莫的IC 50为10 nM，比已知的化学预防剂脱氢表雄酮（DHEA）更有效，后者在相同的JB 6 P+细胞致癌试验中表现出1.0 μ M的IC 50。因此，本申请计划利用这一新发现进行结构-活性关系（SAR）研究，并使用它来选择将在体内动物模型中作为新型癌症化学预防剂进行评价的化合物。将合成已经在申请人的实验室中建立了合成方法的新化合物，并在JB 6 P+细胞中针对12-O-佛波醇-13-肉豆蔻基乙酸酯（TPA）诱导的肿瘤促进进行评价。该应用程序与及时的计划公告（PAR-06-313）非常吻合，该计划有两个目标，即“化学预防新方法的试点测试和开发”。以及通过天然的、合成的、化学预防剂来预防、逆转或延缓癌前病变（以及因此癌症过程）的进展的分子靶点的开发和评估。“我们正在开发合成化学预防剂。我们在本申请中寻求实现两个具体目标。具体目标1。评价申请人实验室合成的新型核苷转运抑制剂作为体外抗肿瘤促进剂，并选择强效和“类药”化合物进行体内动物试验。具体目标2。研究选自特异性目标1的化合物在体内小鼠皮肤癌发生模型中的化学预防能力。申请人实验室开发的新AP-1-SEAP JB 6 P+细胞报告基因试验将与锚定非依赖性克隆形成试验结合使用，以评估靶化合物的体外化学预防活性。还将进行辅助研究，为化学预防剂的开发建立合理的基础。因此，将进行有丝分裂原活化蛋白激酶（MAPK）如ERK、p38和JNK的水平和活化的测定，所述MAPK已显示参与JB 6 P+小鼠表皮癌发生模型中的肿瘤促进信号转导途径。SENCAR小鼠DMBA引发-TPA促进皮肤致癌模型将用于特定目标2中的体内研究，以确定作为化学预防剂的临床前开发的潜在候选药物。将对肿瘤发生率和多样性进行组织学和免疫组织化学分析，以及对体内研究中诱导的肿瘤进行生物标志物分析。该项目的成功将扩大我们的化学预防剂的医疗设备，并发现新的化学预防分子靶点。

DESCRIPTION (provided by applicant): Novel agents are needed for achieving the goals of the growing interest and promise in developing chemoprevention approaches to cancer control (Sporn and Liby, 2005, Smith et al., 2005; Lippman and Lee, 2006; Francis et al., 2006). In pursuing nucleoside transport inhibitors as potential chemopreventive agents, we have discovered that dipyridamole is a potent chemopreventive agent against 12-O-phorbol-13-myristylacetate (TPA) tumor promotion in JB6 P+ cells. With an IC50 of 10 nM, dipyridamole is a much more potent than the known chemopreventive agent dehydroepiandrosterone (DHEA), which exhibited an IC50 of 1.0 ¿M in the same JB6 P+ cell carcinogenesis assay. This application is thus planned to capitalize on this novel finding to conduct a structure-activity relationship (SAR) study, and use it to select compounds that will be evaluated as novel cancer chemoprevention agents in an in vivo animal model. New compounds for which synthetic methods have already been established in the applicant's laboratory will be synthesized and evaluated against 12-O-phorbol-13- myristylacetate (TPA)-induced tumor promotion in JB6 P+ cells. This application fits well with the timely program announcement (PAR-06-313), which has two of its objectives as the "pilot testing and development of new methods of chemoprevention..." and the "development and evaluation of molecular targets to prevent, reverse, or retard progression of precancerous lesions (and, hence, the cancer process) by natural, synthetic, chemopreventive agents." We are developing synthetic chemopreventive agents. We seek to achieve two specific aims in this application. Specific Aim 1. To evaluate novel nucleoside transport inhibitors synthesized in the applicant's laboratory as antitumor promotion agents in vitro, and select potent and "drug-like" compounds for in vivo animal testing. Specific Aim 2. To investigate the chemopreventive ability of compounds selected from Specific Aim 1 in an in vivo mouse skin carcinogenesis model. A new AP-1-SEAP JB6 P+ cell reporter assay developed in the applicant's laboratory will be used in conjunction with an anchorage independent clonogenic assay to assess the in vitro chemopreventive activities of target compounds. Ancillary studies will also be undertaken to establish a rational basis for chemopreventive agent development. Thus, the determination of the levels and of activation of mitogen activated protein kinases (MAPKs) such as ERKs, p38 and JNK, which have been shown to be involved in tumor promotion signal transduction pathways in the JB6 P+ mouse epidermal carcinogenesis model, will be undertaken. The SENCAR mouse DMBA-initiation-TPA-promotion skin carcinogenesis model will be used for the in vivo studies in Specific Aim 2 to identify potential candidates for preclinical development as chemopreventive agents. Tumor incidence and multiplicity will be Histopathological and immunohistochemical analysis will be performed, as well as biomarker analysis of tumors that will be induced in the in vivo studies. The success of this project will expand our armamentarium of chemopreventive agents and uncover novel chemoprevention molecular targets.