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A Selective Small Molecule DNA2 Inhibitor for Sensitization of Human Cancer Cells to Chemotherapy

Liu, Wenpeng and Zhou, Mian and Li, Zhengke and Li, Hongzhi and Polaczek, Piotr and Dai, Huifang and Wu, Qiong and Liu, Changwei and Karanja, Kenneth K. and Popuri, Vencat and Shan, Shu-ou and Schlacher, Katharina and Zheng, Li and Campbell, Judith L. and Shen, Binghui (2016) A Selective Small Molecule DNA2 Inhibitor for Sensitization of Human Cancer Cells to Chemotherapy. EBioMedicine, 6 . pp. 73-86. ISSN 2352-3964. PMCID PMC4856754.

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Cancer cells frequently up-regulate DNA replication and repair proteins such as the multifunctional DNA2 nuclease/helicase, counteracting DNA damage due to replication stress and promoting survival. Therefore, we hypothesized that blocking both DNA replication and repair by inhibiting the bifunctional DNA2 could be a potent strategy to sensitize cancer cells to stresses from radiation or chemotherapeutic agents. We show that homozygous deletion of DNA2 sensitizes cells to ionizing radiation and camptothecin (CPT). Using a virtual high throughput screen, we identify 4-hydroxy-8-nitroquinoline-3-carboxylic acid (C5) as an effective and selective inhibitor of DNA2. Mutagenesis and biochemical analysis define the C5 binding pocket at a DNA-binding motif that is shared by the nuclease and helicase activities, consistent with structural studies that suggest that DNA binding to the helicase domain is necessary for nuclease activity. C5 targets the known functions of DNA2 in vivo: C5 inhibits resection at stalled forks as well as reducing recombination. C5 is an even more potent inhibitor of restart of stalled DNA replication forks and over-resection of nascent DNA in cells defective in replication fork protection, including BRCA2 and BOD1L. C5 sensitizes cells to CPT and synergizes with PARP inhibitors.

Item Type:Article
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URLURL TypeDescription CentralArticle
Shan, Shu-ou0000-0002-6526-1733
Zheng, Li0000-0002-3744-185X
Shen, Binghui0000-0002-4408-407X
Additional Information:© 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( Received 22 February 2016; Received in revised form 29 February 2016; Accepted 29 February 2016; Available online 10 March 2016. Funding Sources: The work was supported by an NIH grant RO1 CA085344, the Margaret E. Early Medical Research Trust grant ADF-1481M to B.H.S., Margaret Early Medical Research Trust grant and ARO W81XWH-09-1-0041 to J.L.C., a Caltech-City of Hope Biomedical Research Initiative to B.H.S. and J.L.C., and K22 grant 5K22CA175262–04 to K.S. Wenpeng Liu is supported by the China Scholarship Council (CSC) during his visit to California Institute of Technology and City of Hope, and K.S. is a CPRIT scholar in cancer biology. We thank the City of Hope Microscopy and Bioinformatics Core Facilities, National Cancer Institute (NCI) designated cancer center support grant P30 CA033572, and Nancy Linford, Ph.D. for her critical reading and editing of the manuscript and S. Howard and J. Stark for their technical support. Author Contributions: L.Z., J.L.C. and B.S. designed the study and supervised the entire project. L.Z., J.L.C., B.S. and K.S. wrote the manuscript. H.L. established the 3-D model and virtually screened the chemical inhibitors. W.L., P.P., J.L.C., Q.W., C.L, and K.K.J. purified the proteins and performed all of the biochemical experiments in the current study. K.S. and V.P. designed and executed the fork protection experiments. Z.L. performed the DNA fiber experiments. Correspondence concerning fork protection experiments may be addressed to K.S. and V.P. M.Z., Z.L., H.D., K.K.J., L.C., performed the cellular functional (SSA, HR, P-RPA resection, replication fork restart) and toxicological assays. S.S. supervised the enzyme kinetics experiments. We declare no financial or other relationships that may lead to a conflict of interest in this study.
Funding AgencyGrant Number
NIHRO1 CA085344
Margaret E. Early Medical Research TrustADF-1481M
Army Research Office (ARO)W81XWH-09-1-0041
Caltech-City of Hope Biomedical InitiativeUNSPECIFIED
China Scholarship CouncilUNSPECIFIED
Subject Keywords:DNA2 inhibitor; Nuclease; Helicase; DNA binding; DNA end resection; DNA replicatoin fork protection; Chemotherapy; Sensitizer; Camptothecin; PARP inhibitor; Cancer
PubMed Central ID:PMC4856754
Record Number:CaltechAUTHORS:20160525-094720168
Persistent URL:
Official Citation:Wenpeng Liu, Mian Zhou, Zhengke Li, Hongzhi Li, Piotr Polaczek, Huifang Dai, Qiong Wu, Changwei Liu, Kenneth K. Karanja, Vencat Popuri, Shu-ou Shan, Katharina Schlacher, Li Zheng, Judith L. Campbell, Binghui Shen, A Selective Small Molecule DNA2 Inhibitor for Sensitization of Human Cancer Cells to Chemotherapy, EBioMedicine, Volume 6, April 2016, Pages 73-86, ISSN 2352-3964, (
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:67340
Deposited By: Tony Diaz
Deposited On:26 May 2016 19:27
Last Modified:09 Mar 2020 13:19

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