MicroRNAs in cleft lip and palate

描述（由申请人提供）：我们将研究一种新的microRNA（miR）介导的遗传途径，该途径对正常颅面发育至关重要。MicroRNA是小的非编码RNA，其在转录后抑制基因表达。使用小鼠条件灭活和染色质免疫沉淀（ChIP），我们最近报道了miR 17 -92簇是心脏祖细胞中Bmp信号传导的直接靶点。我们的初步数据表明，miR 17 -92突变胚胎具有严重的颅面表型，包括唇腭裂（CL/P）和下颌发育不全，这与miR 17 -92是颅面形态发生中BMP靶点的假设一致。这是第一个遗传学证据表明，单个miR或miR簇在哺乳动物CL/P中具有重要的功能。重要的是，miR 17 -92位于人类染色体13q31.3上与13 q缺失综合征相关的唇腭裂的关键区域。此外，miR 17 -92簇与人类癌症如乳腺癌、视网膜母细胞瘤和淋巴瘤有关，表明对miR 17 -92功能的了解具有广泛的人类健康意义。我们最近发表的研究结果表明，miR 17 - 92通过下调祖基因如DiGeorge/velo-cardio-facial syndrome（DGS）基因Tbx 1，在从祖细胞向分化的cll的转变中起关键作用。我们的初步数据表明，miR 17 -92也抑制Tbx 3，尺骨乳腺综合征（UMS）基因。我们建议严格调查miR 17 -92调节途径在发展颅面结构：在具体目标1：我们将调查的假设，miR 17 -92抑制Tbox转录调节因子，Tbx 3，调节唇和腭的发展。在具体目标2中：我们将测试miR 17 -92通过精确调节Tbx 1表达水平是Tbx 1的遗传修饰剂的假设。在具体目标3中，我们将研究Tbx 1和Tbx 3中的miR 17 -92种子位点在体内面中部发育期间直接抑制Tbx 1和Tbx 3时空表达的假设。CL/P的遗传机制还不清楚，新的遗传学见解对未来的诊断测试和家庭咨询至关重要。此外，随着人类基因组测序变得越来越普遍，对CL/P遗传学的深入了解将为患者管理提供关键资源。最后，还有一个长期目标，即根据来自模式生物和人类遗传学工作的可靠科学信息开发新的治疗策略。

DESCRIPTION (provided by applicant): We will investigate a novel microRNA (miR) mediated genetic pathway that is essential for normal craniofacial development. MicroRNAs are small, non-coding RNAs that repress gene expression post-transcriptionally. Using conditional inactivation in mice and chromatin immunoprecipitation (ChIP), we recently reported that the miR17-92 cluster is a direct target for Bmp signaling in cardiac progenitors. Our preliminary data indicate that miR17-92 mutant embryos have severe craniofacial phenotypes, including cleft lip and palate (CL/P) and mandibular hypoplasia, consistent with the hypothesis that miR17-92 is a Bmp-target in craniofacial morphogenesis. This is the first genetic evidence that an individual miR or miR cluster is functionally important in mammalian CL/P. Importantly, miR17-92 is located on human chromosome 13q31.3 in a critical region for cleft lip and palate associated with 13q deletion syndrome. Moreover, the miR17-92 cluster has been implicated in human cancers such as breast cancer, retinoblastoma, and lymphoma indicating that insight into miR17-92 function has broad human health implications. Our recently published findings indicate that miR17- 92 plays a critical role in the transition from progenitor to differentiated cll by downregulating progenitor genes such as the DiGeorge/velo-cardio-facial syndrome (DGS) gene, Tbx1. Our preliminary data suggest that miR17-92 also represses Tbx3, the ulnar mammary syndrome (UMS) gene. We propose to rigorously investigate the miR17-92 regulated pathways in developing craniofacial structures: In Specific Aim 1: We will investigate the hypothesis that miR17-92 inhibits the Tbox transcriptional regulator,Tbx3, to regulate lip and palate development. In Specific Aim 2: We will test the hypothesis that miR17-92, by precisely regulating Tbx1 expression levels, is a genetic modifier for Tbx1. In Specific Aim 3, we will investigate the hypothesis that miR17-92 seed sites in Tbx1 and Tbx3 directly inhibit Tbx1 and Tbx3 spatiotemporal expression during in vivo midface development. There is poor understanding of the genetic mechanisms underlying CL/P. New genetic insights will be critical for diagnostic testing and family counseling in the future. Moreover, an in depth knowledge of genetics of CL/P will provide critical resources for patient management as human genome sequencing becomes more commonplace. Finally, there is the long term goal to develop novel therapeutic strategies based on solid scientific information that will come from work in model organisms and human genetics.