New Approach May Halt Development of Cancer Linked to Mono

A new treatment approach using gene-editing technology may prevent the development of cancer associated with 2 viruses, 1 of which causes mononucleosis, according to a study published in Nature Microbiology.

The viruses, Epstein-Barr virus (EBV) and Kaposi's sarcoma herpesvirus (KSHV), generally remain dormant and hide from being destroyed within the body.

"In most cases, the virus will remain dormant. However, sometimes these viruses can reactivate and lead to abnormal, cancerous cell growth,” lead study author Adam Cheng, a student in the Medical Scientist Training Program at the University of Minnesota Medical School, said in a press release. “But now, in the wake of our research, data suggests it may be possible to suppress the virus indefinitely."

A human DNA enzyme called APOBEC3B is able to mutate and kill EBV and KSHV as it replicates; however, the authors found that both viruses can produce a pair of proteins—BORF2 and ORF61—that bind directly to the enzyme. This renders the enzyme unable to mutate and kill viral DNA, redirecting it from sites where viral replication occurs.

"Our work suggests that by blocking the virus's defense proteins, it may be possible to treat mono and prevent the development of cancers caused by EBV and KSHV," senior author Reuben Harris, PhD, said in a press release. "The viral defense proteins are excellent targets for drug development."

Through the use of CRISPR/Cas9 gene-editing technology, the authors were able to eliminate the defensive proteins, which allowed the APOBEC3B enzyme to mutate the virus and prevent it from replicating in the cells.

“This is a great example of how an unbiased basic science experiment can lead to novel therapeutic opportunities. We could not have anticipated such an unusual role of BORF2 in disabling APOBEC3B and protecting EBV genomes," senior author Lori Frappier, PhD, professor at the University of Toronto, said in the release.

Reference

New strategy discovered toward possible prevention of cancers tied to mono, the “kissing disease” [news release]. https://twin-cities.umn.edu/news-events/research-brief-new-strategy-discovered-toward-possible-prevention-cancers-tied-mono. Accessed November 13, 2018.