Regulation of the LIN28/let-7 pathway in cancer

LIN28/let-7通路在肿瘤中的调控 RNA结合蛋白Lin28A/B控制LET-7肿瘤抑制基因miRNAs的生物发生。重新激活 这种胚胎途径足以促进小鼠的细胞转化和肿瘤形成。 模特们。值得注意的是，Lin28b在神经母细胞瘤、肾母细胞瘤(肾母细胞瘤)、 肝母细胞瘤等。在分子水平上，Lin28a招募尿嘧啶末端转移酶 (TUTase)，ZCCHC6/11，让靶向它们的-7前体RNA被Dis3l2核酸外切酶破坏。 生殖系Dis3l2突变导致Perlman综合征--一种罕见的发育和癌症易感性 疾病与Wilms肿瘤发生风险增加约6,000倍。Dis3l2的体细胞突变也是 在散发性肾母细胞瘤中发现约30%。尽管有遗传证据表明Dis3l2具有肿瘤功能 抑制者其分子和细胞功能仍未解决。同样，贝克维斯-威德曼 胎儿过度生长综合征(BWS)与发生肾母细胞瘤的风险增加约600倍相关，但 BWS中可能的肿瘤抑制基因H19长非编码RNA的分子和细胞功能 仍然不为人知。考虑到miRNA、LIN28、Dis3l2和Wilms之间的紧密联系以及 将H19与LIN28/let-7通路联系起来的初步数据，使我们假设let-7的调节失调 生物发生是Wilms肿瘤发生的统一机制。将进行功能丧失研究，以 解决ZCCHC6/11在LIN28B调节LET-7和生化方法中可能的冗余作用 将被用于阐明Lin28b抑制人类癌细胞LET-7的机制。 将在一组细胞系和原代细胞中测量let-7、H19、Lin28a/B和Dis3l2的相对水平 人类Wilms肿瘤和RNA测序分析将在一个子集上进行。H19-和Dis3l2损耗-和 将在人类癌细胞中进行功能获得实验，以及对基因表达、细胞 生长和致瘤性将被测量。将应用新的方法来确定新的Dis3l2目标 RNA。这将为人类癌细胞中的LIN28/let-7通路提供重要的机制洞察， 揭示H19在儿童癌症中的肿瘤抑制作用，并强调RNA衰变的相关性 通过阐明Dis3l2抑瘤功能在癌症中的作用机制。

Regulation of the LIN28/let-7 pathway in cancer The RNA-binding proteins LIN28A/B control the biogenesis of let-7 tumor suppressor miRNAs. Reactivation of this embryonic pathway is sufficient to promote cellular transformation and drive tumorigenesis in mouse models. Notably, LIN28B functions as an oncogene in neuroblastoma, Wilms tumors (nephroblastoma), hepatoblastoma, and others. At the molecular level, LIN28A recruits the Terminal Uridyl Transferases (TUTases), ZCCHC6/11, to let-7 precursor RNAs targeting them for destruction by the DIS3L2 exonuclease. Germline DIS3L2 mutations cause Perlman syndrome - a rare developmental and cancer predisposition disorder with ~6,000-fold elevated risk of Wilms tumorigenesis. Somatic mutations in DIS3L2 have also been found in ~30% sporadic Wilms tumors. Despite this genetic evidence that DIS3L2 functions as a tumor suppressor its molecular and cellular function remains unaddressed. Similarly, the Beckwith-Wiedemann syndrome (BWS) of fetal overgrowth is associated with ~600-fold elevated risk of developing Wilms tumors, yet the molecular and cellular function of the H19 long-non-coding RNA, a likely tumor suppressor gene in BWS, remains unknown. Considering the strong links between miRNA, LIN28, DIS3L2, and Wilms as well as preliminary data linking H19 to the LIN28/let-7 pathway, leads us to hypothesize that dysregulation of let-7 biogenesis is a unifying mechanism in Wilms tumorigenesis. Loss-of-function studies will be performed to address the possible redundant role of ZCCHC6/11 in LIN28B regulation of let-7, and biochemical approaches will be employed to elucidate the mechanism by which LIN28B suppresses let-7 in human cancer cells. Relative levels of let-7, H19, LIN28A/B, and DIS3L2 will be measured in a panel of cell lines and primary human Wilms tumors and RNA sequencing analysis will be performed on a subset. H19- and DIS3L2 loss- and gain-of-function experiments will be performed in human cancer cells and the effects on gene expression, cell growth, and tumorigenicity will be measured. Novel approaches will be applied to identify new DIS3L2 target RNAs. This will provide important mechanistic insight into the LIN28/let-7 pathway in human cancer cells, uncover the tumor suppressive role of H19 in pediatric cancer, and highlight the relevance of RNA decay mechanisms in cancer by elucidating DIS3L2 tumor suppressive function.