It’s surprisingly difficult for the body’s infection-fighting apparatus to figure out which cells to target.
Immunotherapy — an alternative to cancer therapies that use drugs or radiation to kill cancer cells directly — aims to better equip the body’s existing immune system to kill tumorous cells. Immunotherapy has many benefits, like being able to adapt to fight rapidly mutating cancers. But a key challenge is nudging immune cells in the right direction. Immunotherapy’s response rate, especially for solid tumors, can be quite low.
“You want the T cells to catch the bad guys but you need to first of all identify what the bad guys look like,” said Yifan Wang, a postdoctoral fellow at MD Anderson Cancer Center.
That’s the basis of a system Wang designed that uses ultrasounds to help deliver drugs to macrophages, which eat cancer cells, and also educate the immune system about the cancer cells they should be targeting.. The approach blends bioengineering with Wang’s keen grasp of cell development, leaning on “microbubbles” to deliver an immune-activating drug to cells that use it to fight cancer.
Along with the radiology at UT Southwestern, his team used an antibody that can recognize immune cells and load drugs into these microbubbles, which can then bond with the immune cells. When they burst, they force the drug into the immune cell.
That model could potentially be used in other cells to deliver other types of molecules, Wang says.
Wang’s journey to cancer research began with his undergraduate interest in embryonic development. While he carefully studied the growth of mice in a lab, he was also reading cancer textbooks in his free time. He realized there were some similarities, but also key differences, between the development of a multicelled organism and a tumor.
“One cell becomes two, two cells become four and after a while these cells become differentiated to different things,” he says. “The difference is that embryonic development is well-programmed … the nature of cancer is that it has no rules, it changes very fast and it’s difficult to handle, even within one cancer.”
His ultrasound immune-activating microbubbles are still a way out from actually reaching patients, but Wang said it could start impacting their treatment in three to five years if research and clinical trials progress as planned.
— Mohana Ravindranath
