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

Autor: Mian Zhou, Wenpeng Liu, Katharina Schlacher, Li Zheng, Judith L. Campbell, Piotr Polaczek, Vencat Popuri, Kenneth K. Karanja, Hongzhi Li, Zhengke Li, Qiong Wu, Changwei Liu, Shu-ou Shan, Binghui Shen, Huifang Dai
Rok vydání: 2016
Předmět:
0301 basic medicine
EMSA
electrophoretic mobility shift assay
Carboxylic Acids
RT
radiotherapy
MSFC
Multiple Stage Full Coverage
RMSD
root mean square deviation
DNA replicatoin fork protection
Neoplasms
BLM
Bloom Syndrome
WRN
Werner Syndrome
NCI DTP
National Cancer Institute Developmental Therapeutics Program
Enzyme Inhibitors
FA
Fanconi anemia
Cancer
Nitroquinolines
General Medicine
DNA2
DNA2 nuclease/helicase
3. Good health
Cell biology
MES
mouse embryonic stem
Sensitizer
MCF-7 Cells
DNA2 inhibitor
CPT
camptothecin
Research Paper
DNA re-replication
DNA Replication
EXO1
exonuclesae 1
DNA end resection
DNA repair
HDR
homology direct repair
Biology
SSB
single-strand break
General Biochemistry
Genetics and Molecular Biology
Replication fork protection
Helicase
Small Molecule Libraries
03 medical and health sciences
Nuclease
Replication factor C
Control of chromosome duplication
Drug Therapy
Cell Line
Tumor
Humans
Chemotherapy
Computer Simulation
DSB
double-strand break
DNA binding
FEN1
flap endonuclease 1
HTS
high throughput screening
Replication protein A
Binding Sites
Topoisomerase
DNA replication
DNA Helicases
Molecular biology
High-Throughput Screening Assays
SSA
single-strand annealing
030104 developmental biology
PARP inhibitor
A549 Cells
biology.protein
Camptothecin
Drug Screening Assays
Antitumor
Zdroj: EBioMedicine
ISSN: 2352-3964
DOI: 10.1016/j.ebiom.2016.02.043
Popis: 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.
Highlights • C5 binds to the helicase domain of DNA2 and inhibits its nuclease, ATPase, and helicase activities. • C5 inhibits DNA end resection for DNA double strand break repair and restart of stalled replication forks. • C5 suppresses over-resection of nascent DNA in cells defective in fork protection. • C5 sensitizes cancer cells to chemotherapeutic agents. Most chemotherapeutics introduce DNA lesions that block DNA replication to kill cancer cells. Upregulation of DNA repair proteins in cancer cells is a major reason for human cancer to become resistant to chemotherapeutics. DNA repair proteins such as DNA2 nuclease/helicase have long been proposed as targets for sensitization of cancer cells to chemotherapy. We identify a selective DNA2 inhibitor (C5) and demonstrate that DNA2 inhibition by C5 suppresses cancer cells to rescue stalled replication forks. Consequently, it sensitizes cancer cells to replication fork stalling agents such as camptothecin. Thus, C5 is a promising lead compound for developing new anticancer drugs.
Databáze: OpenAIRE
Externí odkaz: