Cancer becomes exponentially harder to treat once the cells begin to spread throughout the body in a process called metastasis. Metastasis is implicated in 90 percent of all cancer deaths, though not much is known about how the cancer cells are able to escape through the vascular system and spread throughout the body. Once in the blood stream, these metastatic cancer cells can be carried away to form tumors in other organs that may be harder to treat, such as the lungs.
Andrew Wong and Peter Searson of Johns Hopkins University have developed an artificial vessel which allows them to get an unprecedented view of how cancer cells metastasize in real time. Better understanding this process could lead to new methods of treatment. Their paper was published in the journal Cancer Research, and the pair were given a provisional patent for the invention.
“There’s still so much we don’t know about exactly how tumor cells migrate through the body, partly because, even using our best imaging technology, we haven’t been able to see precisely how these individual cells move into blood vessels,” Wong said in a press release. “Our new tool gives us a clearer, close-up look at this process.”
Wong and Searson tested their artificial vessel device with fluorescent-tagged human breast cancer cells that had been embedded into a collagen matrix similar to breast tissue. The vasculature of the device is made out of a transparent material that has the same properties as natural blood vessels. A clear, nutrient-rich medium was circulated through the vessels, replicating blood. Through live-cell fluorescence microscopy, the pair were able to film and track the cancer cells as they maneuvered through the tissue and into the vessel.
“In the past it’s been virtually impossible to see the steps involved in this process with this level of clarity,” added Searson. “We’ve taken a significant leap forward.”
This close-up view allowed the pair to see that the tissue attempted to surround and contain the cancer cells. Unfortunately, some of those cells escaped and began to burrow in to a vulnerable point along the vessel. After a while the force from the artificial bloodstream was great enough to pull the cell into the vessel completely and flush it along.
“Cancer cells would have a tough time leaving the original tumor site if it weren’t for their ability to enter our bloodstream and gain access to distant sites,” Wong continued. “So it’s actually the entry of cancer cells into the bloodstream that allows the cancer to spread very quickly.”
Moving forward, the researchers will use the device to test existing cancer drugs, in order to see if they affect cancer metastasis. In the future, this could even be integrated into the drug discovery process.
“This device allows us to look at the major steps of metastasis as well as to test different treatment strategies at a relatively fast pace,” Wong added. “If we can find a way to stop one of these steps in the metastatic cascade, we may be able to find a new strategy to slow down or even stop the spread of cancer.”