PO.MCB07.01 · 分子与细胞生物学
KIF11在尤因肉瘤和透明细胞肉瘤中调控EWS-FLI1和EWS-ATF1靶基因表达
KIF11 regulates EWS-FLI1 and EWS-ATF1 target gene expression in Ewing and clear cell sarcomas
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
透明细胞肉瘤（CCS）和尤因肉瘤（ES）的5年生存率较低且缺乏靶向疗法。这些癌症由通过染色体易位产生的异常融合蛋白EWS-FLI1（ES）和EWS-ATF1（CCS）驱动。这些融合蛋白通过靶向位于远端基因间位点的增强子来激活和抑制靶基因，从而驱动ES和CCS的存活与增殖。由于这些融合蛋白高度无序的结构，对其进行直接药理学靶向一直很困难。因此，我们寻求鉴定对EWS-FLI1和EWS-ATF1驱动的肿瘤细胞至关重要的替代靶点。通过小分子文库筛选，我们鉴定出KIF11抑制剂可选择性降低ES和CCS细胞的活力。对其潜在作用机制的研究揭示，KIF11抑制剂filanesib在ES和CCS细胞中诱导G2/M期阻滞。这一结果在CCS体内模型以及复发耐药的转移性ES PDX体内模型中均可转化。有趣的是，我们观察到KIF11在ES和CCS中均特异性地在有丝分裂期间与融合蛋白相互作用。此外，敲低KIF11导致EWS-ATF1融合蛋白在整体上以及在有丝分裂期间的可视化观察中丧失。如ATAC-Seq所测量，KIF11敲低导致融合蛋白许多靶向远端基因间位点的染色质可及性显著降低。虽然KIF11与融合蛋白之间的关系仍有待充分探索，但我们的数据表明，KIF11对于维持融合蛋白在有丝分裂期间靶向其下游基因的能力至关重要。我们旨在进一步阐明为何ES和CCS中的融合蛋白在有丝分裂期间仍与靶基因结合。此外，基于这些发现，我们致力于开发KIF11降解剂，以进一步提高在ES和CCS中靶向KIF11的疗效。这项工作部分得到了流式细胞术、分析显微镜、生物统计学与生物信息学、蛋白质组学与代谢组学、分子基因组学核心平台以及H. Lee Moffitt癌症中心与研究所Nikon卓越中心的支持；该机构是由美国国家癌症研究所指定的综合性癌症中心，并部分由Moffitt癌症中心支持基金（P30-CA076292）资助。
查看英文原文 English abstract
Clear Cell Sarcoma (CCS) and Ewing Sarcoma (ES) have a poor 5-year survival rate and lack targeted therapies. The cancers are driven by aberrant fusion proteins generated through chromosomal translocations, EWS-FLI1 (ES) and EWS-ATF1 (CCS). These fusion proteins activate and repress target genes by targeting enhancers located on the distal intergenic sites, thereby driving the survival and proliferation of ES and CCS. Direct pharmacological targeting of these fusion proteins has been difficult due to their highly disordered structure. Therefore, we sought to identify alternative targets essential to EWS-FLI1 and EWS-ATF1 driven tumor cells. Using a small molecule library screen, we identified that KIF11 inhibitors selectively reduce the viability of ES and CCS cells. Investigating the underlying mechanism of action revealed that the KIF11 inhibitor, filanesib, induces G2/M arrest in ES and CCS cells. This result was translatable in CCS in vivo and in relapse-resistant metastatic ES PDXs in vivo . Interestingly, we observed that KIF11 interacted with the fusion proteins specifically during mitosis in both ES and CCS. Furthermore, knockdown of KIF11 results in the loss of the EWS-ATF1 fusion protein globally and visually during mitosis. KIF11 knockdown leads to a significant reduction in chromatin accessibility at many of the fusion proteins' target distal intergenic sites as measured with ATAC-Seq. While the relationship between KIF11 and the fusion proteins remains to be fully explored, our data suggest that KIF11 is essential in maintaining the fusion proteins' ability to target their downstream genes during mitosis. We aim to further elucidate why the fusion proteins in ES and CCS remain bound to target genes during mitosis. Furthermore, based on these findings, we are focused on developing KIF11 degraders to further improve the efficacy of targeting KIF11 in ES and CCS. This work has been supported in part by the Flow Cytometry, Analytical Microscopy, Biostatistics and Bioinformatics, Proteomics and Metabolomics, and Molecular Genomics Cores as well as the Nikon Center for Excellence at the H. Lee Moffitt Cancer Center & Research Institute, a comprehensive cancer center designated by the National Cancer Institute and funded in part by Moffitt's Cancer Center Support Grant (P30-CA076292)
利益披露 Disclosure
H. L. Walker-Mimms, None..
N. Londono, None..
N. Chaudhary, None..
D. Bean, None..
L. N. Darville, None..
J. Serrano-Velez, None..
Y. Liao, None..
J. Yao, None..
A. Smith, None..
F. Kinose, None..
X. Li, None..
J. O. Johnson, None..
U. Rix, None.