Role of polycystin-1 in centrosome duplication and cell cycle control

描述（由申请方提供）：迄今为止，ADPKD囊肿中发现的显著遗传异质性的分子机制仍不清楚。类似的核型改变已被描述为基因组不稳定性的结果。我们的总体假设是PC1失调通过改变正常的中心体功能和细胞周期进程，导致基因组不稳定性，从而导致囊源性过度增殖过程。我们的初步结果已经发现了支持这一主张的有力证据。特异性siRNA介导的PC1抑制改变了体外细胞周期进程和中心体扩增，这一发现在人类ADPKD肾组织中得到证实。中心体完整性的丧失与显著的基因组不稳定性相关。本申请的实验重点是阐明这些新发现的分子机制。第一个具体的目的是确定是否PC1失调导致异常调制的蛋白质参与中心体复制过程。第二个具体目标是评估PC1敲低可能干扰正常细胞分裂周期进程的分子机制。第三个具体的目的是在体内的特征PC1敲低囊性增生和中心体扩增的作用，使用转基因小鼠模型含有多西环素诱导的siRNA特异性鼠PKD1。总之，这些新的研究将扩大药物开发的治疗细胞周期目标，以及我们对疾病过程的理解。 公共卫生相关性 阐明ADPKD过度增殖过程的机制将有助于理解触发囊肿发生的事件。我们的研究将有助于评估细胞周期抑制剂在ADPKD治疗中的治疗潜力。

DESCRIPTION (provided by applicant): To date, the molecular mechanisms responsible for the remarkable genetic heterogeneity found in ADPKD cysts remain unknown. Similar karyotypic alterations have been described consequently to genomic instability. Our overall hypothesis is that PC1 disregulation contributes to the cystogenic hyperproliferative process by altering normal centrosomal functions and cell cycle progression, leading to genomic instability. Our preliminary results have uncovered strong evidence in support of this proposition. Specific siRNA- mediated inhibition of PC1 altered cell cycle progression and centrosome amplification in vitro, a finding corroborated in human ADPKD renal tissues. Loss of centrosome integrity was associated with dramatic genomic instability. The experimental focus of this application is to elucidate the molecular mechanisms underlying these novel findings. The first specific Aim is to determine whether PC1 disregulation causes an abnormal modulation of the proteins involved in the centrosome duplication process. The second specific Aim is to evaluate molecular mechanisms by which PC1 knockdown may cause interference with the normal cell division cycle progression. The third specific Aim is to characterize in vivo the role of PC1 knockdown in cystic hyperproliferation and centrosome amplification, using a transgenic mouse model containing a doxycyclin inducible siRNA specific for murine PKD1. Taken together, these novel studies will expand therapeutic cell cycle targets for drug development, as well as our understanding of the disease process. PUBLIC HEALTH RELEVANCE The elucidation of mechanisms underlying ADPKD hyperproliferative processes will help the understanding of the events triggering cystogenesis. Our study will contribute to ongoing efforts assessing the therapeutic potential for cell cycle inhibitors in the treatment of ADPKD.