Mechanism of Chemoprevention Action and SAR of a Tetrahydroisoquinoline Riboside

描述(由申请人提供)： 结构-活性关系(SAR)指向某种机制的促进剂(S)，而不是NT抑制。例如，在JB6 P+致癌模型中被测试为抗肿瘤促进剂的新型四氢异喹啉核苷NT抑制剂中，关于抗促癌活性的相对效力顺序是：化合物23；化合物3；化合物4；而NT抑制效力顺序相反，化合物4最强(Ki=0.45 nM)，其次是化合物3(Ki=15 nM)，然后是化合物23，最弱(Ki=300 nM)。对化合物23的进一步研究表明，除了抑制TPA诱导的致瘤转化外，它还抑制TPA诱导的AP-1转录因子的激活，这已被证明在TPA诱导的JB6小鼠表皮细胞癌变模型以及许多其他体外和体内致癌过程中具有重要的促癌作用。因此，在这一应用中，我们建议开始研究化合物23的作用机制，并进行抗肿瘤促进SAR，并在体内小鼠皮肤癌变模型中测试化合物的癌症化学预防潜力。其具体目的是：1)合成和测试化合物23的新的芳香族和杂环类似物；2)研究化合物对AP-1 DNA结合的干扰，以及可能解释化合物可能的AP-1依赖的抗肿瘤促进活性的MAPK信号通路；3)在体内小鼠皮肤癌变模型中评价AIM 2的最佳化合物。我们建立的AP-1-SEAP JB6报告细胞将用于体外研究SAR及其机制。我们将使用AP-1-SEAP报告基因和Anclage非依赖细胞生长克隆转化实验来测试待合成的新化合物潜在的化学预防活性。将分析对AP-1 DNA结合、蛋白激酶C的干扰以及已知位于AP-1上游的丝裂原激活蛋白激酶(MAPK)ERK、p38和JNK的作用。Sencar小鼠皮肤两阶段致癌模型将用于评估这类化合物的体内抗肿瘤促进活性，试图确定潜在的先导化合物，用于临床前优化。这一研究计划的成功可能会导致发现新的有望用于皮肤癌化学预防的药物。

DESCRIPTION (provided by applicant): Promotion agents with a structure-activity relationship (SAR) that points to some mechanism(s) other than NT inhibition. For example, among novel tetrahydroisoquinoline riboside NT inhibitors tested as anti-tumor promotion agents in the JB6 P+ carcinogenesis model, the relative order of potency with regard to anti-promotion activity was: Compound 23 > Compound 3 > Compound 4, whereas the NT inhibitory potency order was the opposite, with Compound 4 being the most potent (Ki = 0.45 nM) followed by Compound 3 (Ki = 15 nM) and then followed by Compound 23, the least potent (Ki = 300 nM). Upon further investigation with Compound 23, we have shown that in addition to inhibiting TPA-induced tumorigenic transformation, it also inhibits TPA-induced AP-1 transcription factor activation, which has been shown to have a major role in TPA-induced tumor promotion in the JB6 mouse epidermal cell carcinogenesis model, as well as in many other in vitro and in vivo carcinogenesis processes. Thus, in this application, we propose to initiate an investigation of the mechanisms of action of compound 23, as well as conduct antitumor promotion SAR and test the compounds' cancer chemopreventive potential in an in vivo mouse skin carcinogenesis model. The specific aims are: 1) to synthesize and test new aromatic and heterocyclic analogs of Compound 23, 2) to investigate interference with AP-1 DNA binding, and MAP kinase signaling pathways that might account for the possible AP-1-dependent antitumor promotion activity of the compounds, and 3) to evaluate the best compound from Aim 2 in an in vivo mouse skin carcinogenesis model. AP-1-SEAP JB6 reporter cells created by us will be used for the in vitro investigations of SAR and mechanism. We will use the AP-1-SEAP reporter and anchorage independent cell growth clonogenic transformation assays to test the potential chemopreventive activity of new compounds to be synthesized activity. Interference with AP-1 DNA binding, protein kinase C, as well as the role of the mitogen-activated protein kinases (MAPKs) ERK, p38 and JNK, known to be upstream of AP-1, will be analyzed. The SENCAR mouse skin two-stage carcinogenesis model will be used to assess the in vivo anti-tumor promotion activity of this class of compounds in attempts to identify potential lead compounds for preclinical optimization. The success of this research program may lead to the identification of novel promising agents for skin cancer chemoprevention.