Using measles to treat cancerby Sea Stachura, Minnesota Public Radio
Researchers today know more about the measles than ever, and doctors are using that knowledge to develop new treatments for certain cancers. The first step is to understand how the measles virus infects its host.
Rochester, Minn. — Mayo Clinic researcher Roberto Cattaneo tells a story to illustrate the infectiousness of the measles virus.
In 1848, a group of soldiers was greeted with a big party when they returned to a small island off the coast of Denmark.
"One of them had measles. And within three or four days, almost half of the participants of this dance, which was organized to welcome these soldiers, were infected," said Cattaneo. "So this person alone, in one evening, infected 300 or 400 people of the 800 who attended this dance."
One guy breathes in a room and hundreds of people catch a virus.
Cattaneo is the primary investigator of the Mayo Clinic study that examined exactly how the measles virus infects the body. For centuries doctors assumed, reasonably, the virus infected the cells that line the lung cavity, and then attacked the immune system.
"It's very difficult to follow, technically, what happens when a very small virus enters into an organism with billions of cells," Cattaneo said.
Doctors don't really need to know how the virus accesses the immune system to prescribe treatment. That's straightforward -- bed rest, fluid and something to soothe the itch. Nor will this research create a more effective vaccine. The measles vaccine is one of the best.
The reason Cattaneo studied this old and hearty virus is so he and other researchers could use what they've learned to treat some types of cancers.
A virus is akin to a heat-seeking missile. When it enters the body, the virus searches for the organ or system that it can most easily attack. A stomach virus doesn't begin replication in the bone marrow, but in the stomach.
Since measles appears to attack the lungs first, it might have served as a treatment for lung cancer. But researchers were running into some trouble understanding what receptor the measles virus uses to enter the system.
Cattaneo had done other research that prompted him to wonder if perhaps measles were entering some other part of the body first.
To test that theory, he genetically modified the virus so that it couldn't detect the receptors on the superficial -- called epitheliam -- lung cells.
"It somehow found a way to infect directly the immune cells which peak through the airways. So there is a barrier, but it goes around the barrier," Cattaneo said.
Since the virus naturally works around lung tissue, the measles virus would be a good fit for treating immune system cancers. Cattaneo says researchers can genetically reprogram viruses to target cancer cells instead of healthy cells.
"To make them enter selectively in cancer cells, and replicate selectively in cancer cells," said Cattaneo. "To basically develop these avenues of experimentation, it is necessary to understand precisely how the virus spreads and propagates in its host."
Cattaneo says the measles virus could treat cancers like lymphoma and myeloma. Lymphoma is cancer of white blood cells; myeloma is a cancer of the immune cells in bone marrow called plasma cells.
- All Things Considered, 06/20/2008, 5:24 p.m.