Upstream Regulation and Downstream effectors of c-MYC in Ovarian Cancer

摘要 卵巢癌仍然是女性癌症相关死亡的重要原因， 预计2017年将有约14，080例病例和约14，080例死亡。根据本建议的目标， 迫切需要确定治疗晚期和耐药的高级别浆液性胰腺炎的更好靶点， 卵巢癌（HGSOC）是妇科癌症中最恶性和致命的。其中一种可能性是 c-MYC是一种在大多数癌症（包括HGSOC）中高度丰富的癌基因。我们以前的研究 使用“癌症基因组图谱”（TCGA）数据门户的研究小组显示，HGSOC的复发发生在 c-MYC表达更高的患者更快。此外，小干扰RNA（siRNA）介导的c-MYC 在卵巢癌小鼠模型中，沉默降低了细胞增殖并减少了肿瘤生长。在一起， 这些结果提示c-MYC可能是HGSOC患者的临床相关靶点。虽然 c-MYC过表达的分子机制已经在不同类型的癌症中被广泛研究， 导致HGSOC中c-MYC上调的机制尚未得到解决。的初步结果 我们的研究小组表明，c-MYC可以在HGSOC中通过microRNA进行转录后调节。 微小RNA（miRNAs）是小的非编码RNA，其可以潜在地结合数千种不同的RNA。 信使RNA和抑制蛋白质合成。通过使用生物信息学和分子研究， 几种可能调节卵巢癌细胞中c-MYC表达的miRNA。最重要的是， 这些miRNA的寡核苷酸miRNA模拟物的转染显示，miR-98、miR-106 a和miR-18 a 显著降低c-MYC蛋白水平，并降低卵巢癌细胞的细胞增殖。 总之，我们的数据提供了对HGSOC中c-MYC调控的新机制的深入了解。我们的整体 假设miR-98、miR-106 a和miR-18 a转录后调节c-MYC表达， HGSOC。此外，我们将检验c-MYC调控与细胞存活相关的关键基因的假设 并与HGSOC细胞的顺铂耐药性有关。这一假设将通过以下方式加以解决： 具体目的：（1）鉴定HGSOC细胞中转录后调控c-MYC表达的microRNA; (2)研究siRNA介导的c-MYC沉默的生物学后果和治疗效果， 与miR-98、miR-106 a或miR-18 a模拟物组合，在HGSOC中;和（3）阐明c-MYC下游 卵巢癌细胞中的效应子。我们对耐药分子机制领域的贡献将 详细阐述了c-MYC在HGSOC中的上游调控和下游效应。在 响应“健康差异合作研究中心”（RCMI）的主要任务之一， 该提案将改善少数族裔机构研究人员对基础和转化领域的参与 癌症研究，并将导致培训当地研究生和本科生在尖端 癌症研究中的新技术和新概念。

ABSTRACT Ovarian cancer remains an important cause of female cancer-related deaths, with approximately 22,440 new cases and about 14,080 deaths predicted for 2017. Consistent with the objective of this proposal, there is an urgent need to identify better targets for therapy against advanced and drug-resistant high-grade serous ovarian cancer (HGSOC), the most malignant and lethal of the gynecological cancers. One such possibility is c-MYC, an oncogene highly abundant in most cancers, including HGSOC. Previous studies by our research team using “The Cancer Genome Atlas” (TCGA) data portal showed that recurrence of HGSOC occurred faster for patients with higher c-MYC expression. In addition, small-interference RNA (siRNA)-mediated c-MYC silencing decreased cell proliferation and reduced tumor growth in an ovarian cancer mouse model. Together, these results suggest that c-MYC could be a clinically relevant target for HGSOC patients. Although the molecular mechanisms of c-MYC overexpression have been extensively studied in different types of cancer, the mechanism leading to c-MYC up-regulation in HGSOC have not been addressed. Preliminary results from our research team indicate that c-MYC could be regulated post-transcriptionally by microRNAs in HGSOC. MicroRNAs (miRNAs) are small non-coding RNAs that can potentially bind to thousands of different messenger RNAs and inhibit protein synthesis. By using bioinformatics and molecular studies we identified several miRNAs that potentially regulate c-MYC expression in ovarian cancer cells. Most important, transient transfection of oligonucleotide miRNA mimics for those miRNAs showed that miR-98, miR-106a and miR-18a significantly decreased the c-MYC protein levels, and reduced the cell proliferation of ovarian cancer cells. Together, our data provide insight into novel mechanisms of c-MYC regulation in HGSOC. Our overall hypothesis is that miR-98, miR-106a and miR-18a post-transcriptionally regulate c-MYC expression in HGSOC. In addition, we will test the hypothesis that c-MYC regulates key genes associated with cell survival and with the cisplatin resistance of HGSOC cells. This hypothesis will be addressed by pursuing the following Specific Aims: (1) identify the microRNAs post-transcriptionally regulating c-MYC expression in HGSOC cells; (2) investigate the biological consequences and therapeutic effects of siRNA-mediated c-MYC silencing in combination with miR-98, miR-106a or miR-18a mimics, in HGSOC; and (3) elucidate the c-MYC downstream effectors in ovarian cancer cells. Our contribution to the field of molecular mechanisms of drug resistance will be a detailed elucidation of the Upstream Regulation and Downstream Effectors of c-MYC in HGSOC. In response to one of the main missions of the “Center for Collaborative Research in Health Disparities” (RCMI), this proposal will improve the participation of researchers in minority institutions in basic and translational cancer research and will result in the training of local graduate and undergraduate students in cutting-edge technology and novel concepts in cancer research.