The role and mechanism of RNA m6A modification in the pathogenesis and drug-resistance of prostate cancer

项目名称： RNA m6A修饰在前列腺癌发生和耐药中的作用及机制 项目摘要(摘要)： 背景：N6-甲基腺苷(M6A)修饰是最普遍和最丰富的内部修饰 真核生物信使RNA(MRNAs)，在正常的生物过程中发挥着广泛而重要的作用。 新出现的证据表明，m6A和m6A相关蛋白在人类疾病中也起着关键作用。 包括癌症。前列腺癌(Pca)是最常见的癌症，居第二位。 据估计，美国十多年来的死亡人数。雄激素和雄激素受体(AR)调节 前列腺的正常生长和功能。然而，雄激素和AR信号的异常调节 通路与前列腺癌的发生、发展密切相关。因此，雄激素剥夺疗法 ADT或以AR功能为靶点一直是治疗晚期前列腺癌的主要策略 癌症。然而，目前的治疗策略不能治愈大多数PCa患者，因为耐药和 复发，并最终发展为转移性耐去势前列腺癌(MCRPC)，这是前列腺癌的一个致命阶段 疾病。对阿比特龙和苯扎鲁胺的获得性耐药被认为是 前列腺癌治疗失败和复发。因此，阐明其潜在的分子机制至关重要。 PCa的发病机制和耐药性可能有助于开发有效的新治疗方法 克服目前前列腺癌治疗局限性的方法。RNA m6A修饰由m6A沉积 甲基转移酶复合体由三个核心亚单位METTL3、METTL14和WTAP组成，可能有 作为一种重要的基因表达调节因子，可以影响mRNA的转录、剪接、输出， 稳定性和平移性。在此之前，我们已经报道过METTL3催化的m6A修饰靶基因 在包括前列腺癌在内的人类癌症中起着关键的致癌作用，但它在AR信号激活中起决定性作用 尤其是在耐药的AR信号仍然难以捉摸。我们的初步数据表明，M6A的修饰 在增强子RNAs(ERNAs)上，它是从非编码增强子元件转录的调节性RNA，可能 在PCa的耐药性中也有作用，这需要进一步的系统研究。这项提议的目标是 为了证明METTL3介导的RNA m6A修饰在AR中起关键作用的中心假设 信号转导与前列腺癌的发病机制及耐药。染色质相关调节子的M6A甲基组 RNAs(CarRNAs)和新生RNA将被绘制、分析并与全基因组结合 AR和转录机器。此外，YTHDC1，一种核M6A阅读器蛋白的作用将是系统的 研究它与AR反式激活和全基因组分布的关系，就像它已经做的那样 已知通过与m6A修饰的RNA结合来调节转录激活或抑制。亏损--和 功能增益实验将解决RNA m6A修饰在控制 激活AR信号和下游基因表达，从而有助于揭示 M6A修饰在前列腺癌发病机制中的作用机制。最后，M6A修饰的效果 利用异种移植研究AR耐药突变对AR信号调控的影响 PCA小鼠模型以及患者来源的异种移植(PDX)模型和一组分析将被放置到 研究潜在的分子机制。我们提出的研究将成功揭示RNAm6A的作用 AR信号转导和前列腺癌发病机制的修饰，并有助于评估临床潜在的药理学 抑制PCa中的m6A修饰，尤其是转移性和耐药的PCa。

PROJECT TITLE: The role and mechanism of RNA m6A modification in the pathogenesis and drug-resistance of prostate cancer PROJECT SUMMARY (ABSTRACT): Background: N6-methyladenosine (m6A) modification is the most prevalent and abundant internal modification in eukaryotic messenger RNAs (mRNAs) and plays diverse and important roles in normal biological processes. Emerging evidence suggest that m6A and m6A-assicated proteins also play critical roles in human diseases including cancers. Prostate cancer (PCa) is the most commonly diagnosed cancer with the second leading estimated deaths at the United States for more than a decade. Androgens and androgen receptor (AR) regulate normal growth and function of the prostate gland. However, aberrant regulation of androgens and AR signaling pathway are closely associated with PCa pathogenesis and progression. Thus, androgen deprivation therapies (ADT) or targeting AR function have always been the mainstay of therapeutic strategy against advanced prostate cancers. However, the current therapeutic strategies cannot cure most PCa patients due to drug resistance and relapse, and eventually develop metastatic, castration-resistant prostate cancer (mCRPC), a lethal stage of the disease. The acquired resistance to abiraterone and enzalutamide is considered as the main problem for the treatment failure and relapse of PCa. Therefore, it is crucial to elucidate the molecular mechanisms underlying PCa pathogenesis and drug resistance, which may contribute to the development of effective new therapeutic approaches to overcome the limitations of current treatment for PCa. RNA m6A modification is deposited by m6A methyltransferase complex composed of three core subunits METTL3, METTL14 and WTAP and may have functions as an important regulator of gene expression that can affect mRNA transcription, splicing, export, stability, and translation. Previously, we have reported that METTL3-catalyzed m6A modification of target mRNA plays critical oncogenic roles in human cancers including PCa, but its definitive roles in AR signaling activation and especially in drug-resistant AR signaling remain elusive. Our preliminary data imply that m6A modification on enhancer RNAs (eRNAs), which are regulatory RNAs transcribed from non-coding enhancer elements, may also have roles in drug resistance in PCa, which requires further systematic studies. The goal of this proposal is to prove the central hypothesis that METTL3-mediated RNA m6A modification plays essential roles in AR signaling, PCa pathogenesis and drug resistance. The m6A methylome of chromatin-associated regulator RNAs (carRNAs) and nascent RNAs will be mapped, analyzed and correlated with the genome-wide binding of AR and transcriptional machineries. Also, the role of YTHDC1, a nuclear m6A reader protein, will be systemically examined to investigate its relationship with the transactivation of AR and genome-wide distribution, as it has been known to regulate transcriptional activation or repression via binding to m6A-modified RNAs. Loss- and gain-of-function experiments will address the widespread impact of RNA m6A modification in controlling the activation of AR signaling and downstream gene expression, and thus will help uncover the molecular mechanism underlying the role of m6A modification in PCa pathogenesis. Finally, the effects of m6A modification manipulation in the AR signaling regulation with drug-resistant AR mutations will be explored using a xenograft PCa mouse model, as well as a patient-derived xenograft (PDX) models and a panel of assays will be placed to examine the underlying molecular mechanism. Our proposed study will successfully reveal the role of RNA m6A modification in AR signaling and PCa pathogenesis, and help evaluate the clinical potential pharmacological inhibition of m6A modification in PCa, especially metastatic and drug resistant PCa.