Dr. Cyrus Ghajar

About cyrus

Dr. Cyrus Ghajar is a faculty member at the Fred Hutchinson Cancer  Center in Seattle.  Cyrus grew up in the San Francisco Bay Area, where he used to love playing all kinds of sports through college. He moved to Seattle with his wife and one son, Grayson, in 2013. Since, they’ve added a son (Owen, now 11) and daughter (Ava, now 7) to their family.  Their favorite things to do as a family are to play sports and video games together, and to go skiing and kayaking. 

Cyrus got into science because he loved getting to satisfy his curiosities doing something that could help people survive deadly diseases. His favorite thing about his job is that on any given day, he may see something no one has ever seen (or appreciated) before. 

Three big questions in Cyrus’ field of research are:

1) How are disseminated tumor cells kept dormant

2) Why do they wake up? And,

3) How can we keep them from waking up, or get rid of them all together?

Previous studies have helped Cyrus understand where disseminated tumor cells end up in the body after they leave the original tumor site.  By studying tumors in mice, they found that they live on something called endothelial cells, which make up the tissue that lines blood vessels. Specifically, they found them on the outside of tiny blood vessels in the lungs and in the bone marrow. They found that these endothelial cells can make DTCs go dormant and keep them that way using a molecule called thrombospondin-1, a protein that is made naturally by the body and that plays a role in tumor suppression. They explored how they might use thrombospondin-1 to keep DTCs from waking up, but what they really wanted to do was figure out how to get rid of the DTCs for good.

Ultimately, Cyrus and his collaborators at Fred Hutch wanted to know how the body's own immune responses could be used to find and kill DTCs, rather than a pharmaceutical drug. The cells responsible for immune responses in our bodies are called T cells. According to a recent Fred Hutch article about Cyrus' research, "Our immune system continually surveils our bodies for threats — from viruses, bacteria and our own mutated cells — in order to destroy them and keep us healthy. But that doesn’t always happen when it comes to disseminated tumor cells."  Cyrus said, "We find these cells in the bone marrows of breast cancer patients, so we know they haven’t been surveilled and destroyed by T cells...We wanted to know how these cells persist.”

After several years of research, Cyrus and his collaborators realized the answer was very simple--there were so few DTCS, and also so few T cells capable of finding them, that the chances of successfully killing the DTCs were very, very low. Cyrus compared the likelihood to that of winning the lottery not just once or twice, but many times over. According to Cyrus, "“The only way you could win the lottery over and over again is if you cheat,” he said. “How are we cheating? Not by upping the number of tumor cells, but by upping the number of T cells that can surveil that tumor.”

They found three methods that are very promising for for getting rid of disseminated tumor cells. The first two involve boosting the number of T cells in a patient's body to get around what Cyrus describes as "a numbers game". Instead of relying on the one in a million T cells capable of destroying a disseminated tumor cell, they used an infusion (where drugs or treatment are put into the body through an IV) of genetically engineered T cells that are better at detecting DTCs than natural T cells. They found two different kinds of genetically engineered T cells that do a very good job of this--adding in millions of them got rid of nearly all the DTCs. 

The third method is a vaccine. Instead of injecting parts of a virus, like the vaccines we get for flu, covid, etc., and training the body to fight it off, they developed a vaccine that stimulated the body to make many of the T cells that could recognize and kill DTCs. Instead of injecting a patient with millions of lab-made T cells, the vaccine allows the body to make its own.

This is very exciting and cutting edge research that has the potential to save many, many lives! If you'd like to read the article referred to here, you can do so here. It goes into quite a bit more depth, but is still pretty accessible.