“This is the great thing about the work, because once you have more insight about how a pathway works, you tackle one of the biggest hurdles in cancer immunology.”
Rosa Barreira da Silva is a postdoctoral fellow at Genentech in the Department of Cancer Immunology.
Barreira da Silva is researching how cancer interacts with the body’s natural defenses. Patients who didn’t benefit from immunotherapy had elevated levels of what are called chemokines, proteins emitted by tumors that would normally signal to the immune system that something was amiss. Barreira da Silva discovered an enzyme called DPP4 was interrupting the normal process, modifying the cancer proteins in a way that shielded them from the immune system and allowed tumors to grow unbothered.
There are widely available drugs that block DPP4, approved by the FDA to treat type 2 diabetes by lowering blood sugar. Barreira da Silva tested the DPP4 inhibitors in cancer-afflicted mice, and the results affirmed her theory: By keeping the enzyme at bay, chemokines alerted the immune system, which attracted cancer-killing cells to the site of the malignancy.