Once the assay for the RNAseH was developed, Tavis and his team were able to try out this theory.
"We found that what worked with the first enzyme worked with the second enzyme," Tavis said. "This is a proof of principle. We're on the right track."
Tavis now has a measuring tool and evidence that a number of the techniques that stopped HIV, including inhibitors of HIV RNAseH, could also inhibit the hepatitis B virus RNAseH, showing that the parallels held true. From there, Tavis and his team went on to prove that hepatitis B replication could in fact be stopped in cells with drugs that targeted the elusive second enzyme, RNAseH.
Hope on the Horizon
With these promising advances, researchers say that the search for anti-hepatitis B RNAseH drugs is now feasible and that using similar anti-HIV compounds as a guide is likely to have a high chance of success.
The research team's next step will be to study several variations of hepatitis B virus, different genotypes of the virus, to be able to measure and study the RNAseH enzyme in all forms of the virus. Current findings demonstrated success in only some genotypes. Findings from the current study suggest some promising avenues as researchers will now attempt to block RNAseH in the two most common genotypes, B and C.
In addition, researchers will aim to improve the strength and speed of the RNAseH assay for high throughput screening, a process for rapidly screening many thousands of compounds. These developments will clear the way for full-scale antiviral drug discovery.
Investigators have reason to hope that combining a new anti-hepatitis B RNAseH drug with the existing drugs may suppress the virus far enough to cure patients with hepatitis B.
"I anticipate a new drug targeting the second enzyme would be used together with the existing drugs," Tavis said. "They jam different parts of the
|Contact: Carrie Bebermeyer|
Saint Louis University