Polymerase θ Coordinates Multiple Intrinsic Enzymatic Activities during DNA Repair.
Genes (Basel)
; 12(9)2021 08 25.
Article
in En
| MEDLINE
| ID: mdl-34573292
ABSTRACT
The POLQ gene encodes DNA polymerase θ, a 2590 amino acid protein product harboring DNA-dependent ATPase, template-dependent DNA polymerase, dNTP-dependent endonuclease, and 5'-dRP lyase functions. Polymerase θ participates at an essential step of a DNA double-strand break repair pathway able to join 5'-resected substrates by locating and pairing microhomologies present in 3'-overhanging single-stranded tails, cleaving the extraneous 3'-DNA by dNTP-dependent end-processing, before extending the nascent 3' end from the microhomology annealing site. Metazoans require polymerase θ for full resistance to DNA double-strand break inducing agents but can survive knockout of the POLQ gene. Cancer cells with compromised homologous recombination, or other DNA repair defects, over-utilize end-joining by polymerase θ and often over-express the POLQ gene. This dependency points to polymerase θ as an ideal drug target candidate and multiple drug-development programs are now preparing to enter clinical trials with small-molecule inhibitors. Specific inhibitors of polymerase θ would not only be predicted to treat BRCA-mutant cancers, but could thwart accumulated resistance to current standard-of-care cancer therapies and overcome PARP-inhibitor resistance in patients. This article will discuss synthetic lethal strategies targeting polymerase θ in DNA damage-response-deficient cancers and summarize data, describing molecular structures and enzymatic functions.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Nucleic Acid Synthesis Inhibitors
/
DNA-Directed DNA Polymerase
/
DNA Breaks, Double-Stranded
/
DNA End-Joining Repair
/
Neoplasms
Type of study:
Prognostic_studies
Limits:
Animals
/
Humans
Language:
En
Journal:
Genes (Basel)
Year:
2021
Document type:
Article
Affiliation country:
Estados Unidos