APOBECs: The Virus-Fighting Enzymes That Become Cancer’s Villains – And How Science & Medicine in San Antonio is Tackling This Frontline Battle

Science & Medicine is a collaboration between TPR and The University of Texas Health Science Center at San Antonio that explores how scientific discovery in San Antonio advances the way medicine is practiced everywhere. One of the most versatile tools in our immune system is an enzyme called apolipoprotein B mRNA-editing enzyme, catalytic polypeptide — better known as APOBECs. “From a virus perspective, these enzymes protect us,” said Reuben Harris, PhD, chair of the UT Health San Antonio Department of Biochemistry and Structural Biology.

APOBECs are DNA mutating enzymes that normally serve to protect us from invading viruses. However, in many instances in cancer becomes dysregulated. Instead of destroying viruses, they end up destroying our genomes. “So in cancer the good guys can become villains that do catastrophic damage,” said Harris. “But what we propose is in a lot of tumors, one of the frontline standards of care is surgical resection and therapy.” After an APOBEC positive tumor is removed, if you could shut off these enzymes, you could reduce the risk that the cancer will return or spread or change in such a way that it becomes resistant to medication.

“If we can stop that, we can make all of these adverse events much less likely to happen,” he said. “That’s something we get really excited about every day.” Reuben S. Harris, PhD, is Principle Investigator, Professor and Chairman of Biochemistry and Structural Biology at UT Health San Antonio.