Digital drugs

by Tyler Shendruk

Published: Feb 2

The problem
IT IS POSSIBLE to cure certain cancers by surgically removing the tumors, but this requires that every single cancer cell is extracted. If any cancer cells remain, or if they spread to further, undetected sites, only remission has been achieved—not a complete cure.
Therefore, tracking surviving cancer cells is vitally important. Given the opportunity, they will grow into deadly new tumors. Unfortunately, treatments that can deal with remaining cells, like radiation or chemotherapy, indiscriminately kill cancer cells and healthy cells alike, making the treatments brutal on the body. Targeted therapies are at the forefront of cancer treatment.

The researcher
In the Department of Chemistry, professor Maxim Berezovski has a laboratory that is, in many ways, obsessed with selectivity. In one project, Berezovski studies separation techniques that can teach him about biochemical reaction rates. In another, he isolates biomarkers from cells. In yet another, he marks cells of one type without marking any of the others. The flags he uses to mark cells are called aptamers.

The project
Aptamers are short polymers of nucleic acids that bind to specifically targeted molecules. In many ways, researchers can use them as synthetic artificial antibodies. Berezovski builds them from little chunks of DNA to target the surface of different cells, in particular cancer cells. The selectivity of aptamers makes them perfect for marking or attacking cancer cells while ignoring the healthy ones.

The key
Berezovski proposes that once a tumor is surgically removed, a cocktail of aptamers can be specifically designed for those individual tumor cells. Tumors that reappear are actually clones of the original tumor. This means that the personal recipe of aptamers for the original tumor could be kept as a digital record in case of recurrence. Since there is no need to keep the actual aptamers, Berezovski refers to this record as a digital drug.
The digital drug could be used to produce a personalized mixture of aptamers that will target clones of the original tumor. Doctors could then attach labels to the aptamers to track cancer cells that escaped surgical removal or to identify new tumors. The selectivity of aptamers could even direct the delivery of toxins or medicine specifically to the tumor, allowing for a more finite cancer survival rate.