title: Small-molecule inhibitors of APE1 DNA repair function: an overview.
abstract: APE1 is a multifaceted protein that orchestrates multiple activities in the cell, one of which is the preservation of genomic integrity; a vital process that takes place in the context of the base excision repair (BER) pathway. Studies have implicated APE1 in rendering cancerous cells less vulnerable to the effects of DNA-damaging agents that are commonly used for the treatment of cancer. Furthermore, suppression of APE1 expression in cancer cell lines is accompanied by the potentiation of the activity of cytotoxic agents. As a result, major efforts have been directed towards the identification of small-molecule inhibitors of this DNA-repair enzyme. Herein, we review all patented small-molecule APE1 inhibitors reported prior to 2011. Unfortunately, the potency and selectivity of many of the reported inhibitors were not disclosed by the original authors, and at present it is unclear if APE1 is a bona fide target for many of the purported inhibitors. Moreover, cellular activity and toxicity of many inhibitors remain to be established. Since this is the first comprehensive review of small molecule APE1 inhibitors, we present all compounds reported to inhibit APE1 activity with an IC50 value ≤ 25 μM. Efforts towards a careful validation and optimization of these compounds are warranted. Furthermore, we explore potential allosteric drug-binding sites on the protein as an alternative approach for modulating the activity of this multifunctional protein. In addition, we give an overview of APE2, as well as other APE1 homologues in some disease-causing pathogens. Finally, given the universal importance of DNA repair, as well as the considerable conservation of repair proteins across all living organisms, we propose targeting the AP endonuclease activity of pathogens by the compounds discussed in this review, thereby expanding their therapeutic potential and application.
authors: Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, School of Pharmacy, 1985 Zonal Avenue, Los Angeles, CA 90089, USA.
authors: Rasha I
authors: RI
authors: Al-Safi
authors: Srinivas
authors: S
authors: Odde
authors: Yumna
authors: Y
authors: Shabaik
authors: Nouri
authors: N
authors: Neamati
mesh_terms: D020134:Catalytic Domain; D004260:DNA Repair / Q000187:drug effects*; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004720:Endonucleases; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D064251:Multifunctional Enzymes; D009369:Neoplasms / Q000188:drug therapy / Q000201:enzymology; D054852:Small Molecule Libraries / Q000737:chemistry* / Q000627:therapeutic use; D013329:Structure-Activity Relationship
chemical_list: D004791:Enzyme Inhibitors; D064251:Multifunctional Enzymes; D054852:Small Molecule Libraries; D004720:Endonucleases; C085108:APEX1 protein, human; C530688:APEX2 protein, human; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase