Inhibition of Poly(ADP-Ribose) Polymerase by Nucleic Acid Metabolite 7-Methylguanine

• Published in: Actanaturae Vol. 8; no. 2; pp. 108 - 115
• Main Authors: Nilov, D K, Tararov, V I, Kulikov, A V, Zakharenko, A L, Gushchina, I V, Mikhailov, S N, Lavrik, O I, Švedas, V K
• Format: Journal Article
• Language: English
• Published: Russia (Federation) A.I. Gordeyev 01.04.2016
• Subjects: docking; molecular modeling; PARP inhibitors
• ISSN: 2075-8251
• DOI: 10.32607/20758251-2016-8-2-108-115

The ability of 7-methylguanine, a nucleic acid metabolite, to inhibit poly(ADP-ribose)polymerase-1 (PARP-1) and poly(ADP-ribose)polymerase-2 (PARP-2) has been identified in silico and studied experimentally. The amino group at position 2 and the methyl group at position 7 were shown to be important substituents for the efficient binding of purine derivatives to PARPs. The activity of both tested enzymes, PARP-1 and PARP-2, was suppressed by 7-methylguanine with IC50 values of 150 and 50 μM, respectively. At the PARP inhibitory concentration, 7-methylguanine itself was not cytotoxic, but it was able to accelerate apoptotic death of BRCA1-deficient breast cancer cells induced by cisplatin and doxorubicin, the widely used DNA-damaging chemotherapeutic agents. 7-Methylguanine possesses attractive predictable pharmacokinetics and an adverse-effect profile and may be considered as a new additive to chemotherapeutic treatment.