Chemical Inhibitors of CREB-mediated Gene Transcription

描述（由申请人提供）：拟议研究的目标是开发CREB （camp反应元件结合蛋白）介导的基因转录的小分子抑制剂，作为潜在的抗癌药物。近年来，越来越多的证据表明，CREB参与了癌细胞的永生化、转化和转移的调控。在某些癌症患者（如急性白血病、前列腺癌和乳腺癌）中，CREB的表达与癌症表型相关，包括癌细胞分化、转移、复发时间和生存。这表明抑制CREB的转录活性可能是一种很有前景的抗癌治疗策略。与这一假设一致，在黑色素瘤和肺癌细胞系中表达显性阴性CREB突变体或下调白血病细胞系中CREB的表达可减少癌细胞的转化表型。此外，在体外和体内实验中，将CRE诱饵寡核苷酸递送到人乳腺癌或前列腺癌细胞中，可显著抑制肿瘤细胞的生长，而在正常细胞中进行的类似实验没有显示出毒性。这些结果表明，从药理学上抑制CREB活性可能是治疗癌症的一种极好的策略。然而，creb介导的小分子抑制剂尚未开发用于抗癌活性评估。我们最近开发了一种新的检测方法，专门研究CREB-CBP相互作用，并发现萘酚as - e在体外和细胞中都是CREB-CBP相互作用的小分子抑制剂。此外，我们发现该化合物能够通过诱导许多不同癌细胞的凋亡来抑制癌细胞的生长，而不管它们的p53状态如何。基于这些有希望的初步结果，我们建议进一步评估其治疗潜力并优化其抗癌活性。本研究的目的如下：1)通过设计和合成萘酚as - e作为抗癌剂和CREB-CBP相互作用抑制剂的结构-活性关系（SAR）；2)开发一系列强效和水溶性萘酚as - e衍生物，作为结构研究的探针；3)探讨萘酚AS-E及其衍生物抗癌活性需要creb介导的基因转录的假设。CREB介导基因转录的小分子抑制剂的开发不仅将为癌症的治疗提供潜在的治疗方法，而且还为在体外和体内操纵CREB的活性进一步剖析其生物学功能提供了有力的工具。

DESCRIPTION (provided by applicant): The goal of the proposed research is to develop small molecule inhibitors of CREB (cAMP-response element binding protein)-mediated gene transcription as potential anticancer agents. Recently, accumulating evidence has revealed that CREB participates in the regulation of immortalization, transformation and metastasis of cancer cells. In some cancer patients (e.g. acute leukemia, prostate cancer and breast cancer), expression of CREB correlated with cancer phenotypes including cancer cell differentiation, metastasis, time to relapse and survival. This suggests that inhibiting the transcription activity of CREB could be a promising strategy for anticancer treatment. Consistent with this hypothesis, expression of a dominant-negative CREB mutant in melanoma and lung cancer cell lines or down-regulating the expression of CREB in leukemia cell lines reduced the transforming phenotypes of the cancer cells. Moreover, delivery of a CRE decoy oligonucleotide into human breast cancer or prostate cancer cells led to significant inhibition of tumor cell growth both in vitro and in vivo while similar experiments in normal cells showed no toxicity. These results indicate that pharmacologically inhibiting CREB activity could be an excellent strategy for cancer treatment. However, small molecule inhibitors of CREB-mediated have not been developed for evaluation of anticancer activity. We recently developed a novel assay to specifically look at CREB-CBP interaction and discovered naphthol AS-E as a small molecule inhibitor of CREB-CBP interaction both in vitro and in cells. Moreover, we found that this compound was able to inhibit cancer cell growth by inducing apoptosis in a number of different cancer cells irrespective of their p53 status. Based on these promising preliminary results, we propose to further evaluate its therapeutic potential and optimize its anticancer activity. The following aims will be addressed: 1) To define the structure-activity relationships (SAR) of naphthol AS-E as an anticancer agent and inhibitor of CREB-CBP interaction by designing and synthesizing analogs with different substitutions on the appendant phenyl ring; 2) To develop a novel series of naphthol AS-E derivatives with enhanced potency and aqueous solubility as probes for structural studies; 3) To investigate the hypothesis that CREB-mediated gene transcription is required for anticancer activity displayed by naphthol AS-E and its derivatives. Development of small molecule inhibitors CREB-mediated gene transcription will not only lead to potential therapeutics for cancer, but also provide a powerful tool to manipulate CREB's activity in vitro and in vivo to further dissect its biological functions. PUBLIC HEALTH RELEVANCE: The proposed research is to develop chemical inhibitors of CREB-mediated gene transcription. These inhibitors are expected to be potential candidates as anticancer agents for a variety of cancers.