Antiviral Res. 2019 Feb 12. pii: S0166-3542(18)30640-5. doi: 10.1016/j.antiviral.2019.02.005. [Epub ahead of print]
Inhibition of HBV replication by N-hydroxyisoquinolinedione and N-hydroxypyridinedione ribonuclease H inhibitors.
Edwards TC1, Mani N2, Dorsey B3, Kakarla R4, Rijnbrand R5, Sofia MJ6, Tavis JE7.
Author information
1
Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, MO, USA; Saint Louis University Liver Center, Saint Louis University School of Medicine, St. Louis, MO, USA. Electronic address: [email protected].
2
Arbutus Biopharma Incorporated, Warminster, PA, USA. Electronic address: [email protected].
3
Arbutus Biopharma Incorporated, Warminster, PA, USA. Electronic address: [email protected].
4
Arbutus Biopharma Incorporated, Warminster, PA, USA. Electronic address: [email protected].
5
Arbutus Biopharma Incorporated, Warminster, PA, USA. Electronic address: [email protected].
6
Arbutus Biopharma Incorporated, Warminster, PA, USA. Electronic address: [email protected].
7
Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, MO, USA; Saint Louis University Liver Center, Saint Louis University School of Medicine, St. Louis, MO, USA. Electronic address: [email protected].
Abstract
We recently developed a screening system capable of identifying and evaluating inhibitors of the Hepatitis B virus (HBV) ribonuclease H (RNaseH), which is the only HBV enzyme not targeted by current anti-HBV therapies. Inhibiting the HBV RNaseH blocks synthesis of the positive-polarity DNA strand, causing early termination of negative-polarity DNA synthesis and accumulation of RNANA heteroduplexes. We previously reported inhibition of HBV replication by N-hydroxyisoquinolinediones (HID) and N-hydroxypyridinediones (HPD) in human hepatoma cells. Here, we report results from our ongoing efforts to develop more potent anti-HBV RNaseH inhibitors in the HID/HPD compound classes. We synthesized and screened additional HIDs and HPDs for preferential suppression of positive-polarity DNA in cells replicating HBV. Three of seven new HIDs inhibited HBV replication, however, the therapeutic indexes (TI = CC50/EC50) did not improve over what we previously reported. All nine of the HPDs inhibited HBV replication with EC50s ranging from 110 nM to 4 μM. Cellular cytotoxicity was evaluated by four assays and CC50s ranged from 15 to >100 μM. The best compounds have a calculated TI of >300, which is a 16-fold improvement over the primary HPD hit. These studies indicate that the HPD compound class holds potential for antiviral discovery.