Chemical genetics of LIN-28 in C. elegans

描述（由申请人提供）：C。线虫lin-28基因编码进化上保守的RNA结合蛋白，其在涉及let-7家族microRNA的途径中起作用，以控制祖细胞从更增殖到更不增殖的行为的转变。类似地，哺乳动物LIN-28调节let-7家族microRNA的生物发生，并且还促进干细胞多能性和增殖行为。LIN-28还在人类癌细胞中的Myc致癌信号传导的下游起作用，部分通过抑制肿瘤抑制微RNA。因此，LIN-28代表了开发抗癌治疗剂的可行靶标。C. elegans和人类的LIN-28在增殖和多能性中的作用促使我们提出使用C. elegans作为筛选LIN- 28的小分子抑制剂的有效且廉价的系统。我们将利用与LIN-28在C. elegans来鉴定可以抑制LIN-28活性并抑制这些表型的化合物。我们将利用C. elegans lin-28途径，以将我们的药物分类为直接影响蠕虫中LIN-28蛋白的药物，因此最有可能在人类细胞中发挥类似的功能。 我们的主要目标是建立C。用于LIN-28的化学遗传学的elegans系统。与此同时，我们将通过将促进LIN-28靶向药物在临床上快速过渡的措施纳入我们的战略措施，进一步最大化该项目的潜在回报。因此，使用哺乳动物癌细胞系模型，我们将对我们最初在C. elegans来确定它们在哺乳动物细胞中的功效。最重要的是，我们对蠕虫的筛选将利用FDA批准的药物库，因此在C.优雅 公共卫生相关性：LIN-28在调节let-7家族的肿瘤抑制miRNA的生物发生中起主要作用，并且在Myc癌基因信号传导的下游起作用。因此，LIN-28代表了人类癌症背景下的潜在药物靶标。我们建议利用线虫C. elegans作为体内系统来有效筛选可抑制LIN-28活性的小分子药物。我们通过抑制C. elegans将形成进一步测试其在哺乳动物癌细胞系中抑制LIN-28的能力的基础。由于我们将在我们的筛选库中包括FDA批准的药物，因此我们将鉴定的抗LIN-28药物具有几乎立即临床应用的前景。

DESCRIPTION (provided by applicant): The C. elegans lin-28 gene encodes an evolutionarily conserved RNA- binding protein that functions in pathways involving let-7-family microRNAs to control transitions from more proliferative to less proliferative behavior for progenitor cells. Similarly, mammalian LIN-28 regulates the biogenesis of let-7- family microRNAs and also promotes stem cell pluripotency and proliferative behavior. LIN-28 also functions downstream of Myc oncogenic signaling in human cancer cells, in part by inhibiting tumor suppressor microRNAs. Thus, LIN-28 represents a viable target for development of anti-cancer therapeutics. The conservation between C. elegans and humans of the roles for LIN-28 in proliferation and pluripotency prompts us to propose to use C. elegans as an efficient and inexpensive system to screen for small molecule inhibitors of LIN- 28. We will take advantage of the striking developmental phenotypes associated with LIN-28 gain of function in C. elegans to identify compounds that can inhibit LIN-28 activity and suppress those phenotypes. We will leverage the well- developed genetics of the C. elegans lin-28 pathway to triage our drugs for those that directly affect the LIN-28 protein in worms, and hence are most likely to function similarly in human cells. Our main goal is to establish the feasibility of the C. elegans system for chemical genetics of LIN-28. At the same time, we will further maximize the potential payoff from the project by incorporating into our strategy measures that facilitate the rapid transition of LIN-28-targeting drugs in the clinic. Accordingly, using mammalian cancer cell line models, we will perform follow-up tests of candidate LIN-28 inhibitors that we initially identify in C. elegans to establish their efficacy in mammalian cells. Most importantly, our screens on worms will utilize libraries of FDA-approved drugs, and therefore there is the prospect of almost immediate clinical application against human cancer of anti-LIN-28 drugs identified in C. elegans. PUBLIC HEALTH RELEVANCE: LIN-28 plays a major role in regulating the biogenesis of the tumor suppressor miRNAs of the let-7 family and does so downstream of Myc oncogene signaling. LIN-28 therefore represents a potential druggable target in the context of human cancer. We propose to utilize the nematode C. elegans as an in vivo system to efficiently screen for small molecule drugs that can inhibit LIN-28 activity. The chemical compounds the we identify by their inhibition of LIN-28 function in C. elegans will form the basis for further testing of their ability to inhibit LIN-28 in mammalian cancer lines. Since we will include in our screens libraries of FDA-approved drugs, there is the prospect of almost immediate clinical application of anti-LIN-28 drugs that we will identify.