PO.ET02.12 · 实验与分子治疗
小分子JKYN-1抑制DNA修复蛋白RAD51的分子表征
Molecular characterization of inhibition of the DNA repair protein RAD51 by the small molecule JKYN-1
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
癌细胞形成大肿瘤并快速适应不断变化的环境条件的能力，源于其固有的遗传不稳定性，而这种不稳定性也使其对细胞毒性药物敏感。癌细胞高度依赖RAD51蛋白(在许多肿瘤中过表达)的作用，以在DNA损伤和复制应激(RS)中存活(Cells 12: 1169-1189, 2023. https://doi.org/10.3390/cells12081169)。IBR家族的RAD51抑制剂不仅在低微摩尔浓度下作为单药抑制肿瘤细胞增殖，还与多种现有抗癌药物协同作用以阻止生长并诱导细胞死亡(J Pharmacol Expt Ther, 364: 46-54, 2018. doi.org/10.1124/jpet.117.241661)。为更好地理解这种协同相互作用，并有助于改善对癌细胞的选择性，从而提高潜在的临床应用价值，我们采用多种方法对IBR2、IBR120和JKYN-1的活性进行了表征。JKYN-1的结构是对IBR120的修饰，作为单药增殖抑制剂其效力强5倍。如先前对IBR2和IBR120所证明的，JKYN-1与现有抗癌药物联用时，可协同抑制代表众多肿瘤来源的细胞系的增殖。在羟基脲处理的人乳腺癌MCF-7细胞中，B02(一种已确立的RAD51抑制剂，Mol Cancer Ther 20:1257-1269, 2021. doi: 10.1158/1535-7163.MCT-20-0252)和JKYN-1显著抑制了RAD51病灶的形成，同时增加了pRPA病灶的形成(RS的标志)。在暴露于电离辐射的人骨肉瘤U2OS细胞中，JKYN-1单独即可减少RAD51病灶的形成。在机制上，JKYN-1损害了RAD51依赖性的D-loop形成。JKYN-1抑制了RAD51的多聚化及其ATP酶活性，后者负责修复完成后RAD51从DNA上的正常解离。因此，JKYN-1如预期般抑制RAD51功能。这一作用如何促成与抗癌药物观察到的协同效应仍在研究中。目前正在研究JKYN-1的衍生物以改善其药代动力学特性。本研究由Sarissa, Inc.、Breast Cancer Canada和London Health Sciences Foundation资助。
查看英文原文 English abstract
The ability of cancer cells to form large tumors and rapidly adapt to changing environmental conditions results from inherent genetic instability that also confers upon them sensitivity to cytotoxic agents. Cancer cells rely heavily on the action of the protein RAD51, overexpressed in many tumors, to survive DNA damage and replication stress (RS) (Cells 12: 1169-1189, 2023. https://doi.org/10.3390/cells12081169). The IBR-family RAD51 inhibitors not only inhibit tumor cell proliferation as single agents at low micromolar concentrations, but also work synergistically with a variety of established anticancer agents to stop growth and induce cell death (J Pharmacol Expt Ther, 364: 46-54, 2018. doi.org/10.1124/jpet.117.241661). To better understand the synergistic interaction and help improve selectivity against cancer cells, and thus potential for clinical use, we have characterized the activity of IBR2, IBR120, and JKYN-1 using a variety of methods. JKYN-1, the structure of which is a modification of IBR120, is 5-fold stronger as a single-agent inhibitor of proliferation. As demonstrated previously for IBR2 and IBR120, JKYN-1 synergistically inhibited proliferation of cell lines representative of numerous tumor sources in combination with established anticancer drugs. In hydroxyurea-treated human breast carcinoma MCF-7 cells, B02, an established RAD51 inhibitor (Mol Cancer Ther 20:1257-1269, 2021. doi: 10.1158/1535-7163.MCT-20-0252), and JKYN-1 markedly suppressed formation of RAD51 foci while increasing pRPA foci formation, a marker of RS. In human osteosarcoma U2OS cells exposed to ionizing radiation, JKYN-1 alone reduced RAD51 foci formation. Mechanistically, JKYN-1 impaired RAD51-dependent D-loop formation. JKYN-1 inhibited multimerization of RAD51 as well as its ATPase activity, responsible for normal dissociation of RAD51 from DNA following completion of repair. Therefore, JKYN-1 acts as expected in inhibiting RAD51 function. How this contributes to the synergy observed with anticancer agents is being investigated. Derivatives of JKYN-1 are currently being studied for improvements to pharmacokinetic properties. Funded by Sarissa, Inc., Breast Cancer Canada, and London Health Sciences Foundation.
利益披露 Disclosure
P. Ferguson, None..
M. Vincent, None..
Y. Najajreh, None..
M. Black, None..
S. Sharma Saha, None..
M. Thomas, None..
O. Lord, None..
S. Ritter, None..
J. Masson, None..
B. Shilton, None..
J. Koropatnick, None.