What causes cancer cells to become metastatic, moving beyond their local environment to infiltrate other parts of the body? Some researchers have called metastasis “the most dangerous event in cancer,” and many believe that a better understanding of metastasis could lead to new cancer treatments.
Microfluidics researchers have long been investigating metastasis, because metastasis is all about cell movement. When cells move inside the body, they are often moving in microfluidic-type environments. Using microfluidic platforms, scientists gain fine spatial and temporal control of the cell microenvironment, something that’s difficult-to-impossible using conventional methods. A few examples of how microfluidic technology is being used to investigate metastasis:
Microfluidics can help us understand what external influences cause cell motion Much of the initial work in applying microfluidics to metastasis has focused on studying how cancer cells respond to concentration gradients of chemicals suspected to drive cell motion. For example, Noo Li Jeon’s group at UC Irvine, a leader in using microfluidics to generate microscale chemotactic gradients, created a platform to investigate how epidermal growth factor may cause breast cancer cells to move (2006, free full text). David Beebe’s group hasexpanded this concept to three dimensions (2008, free full text).
More recently, Mehmet Toner and Daniel Irimia have found using microfluidics that chemotactic gradients may not be necessary for cancer cell motion. Their work, published in 2009, implies that a simple microchannel may be sufficient to get cancer cells moving (nice video here!).
Microfluidics can detect circulating cancer cells Toner’s group has also developed a microfluidic platform for detecting rare metastatic cancer cells circulating in the blood (make sure to click on the video) for earlier detection of metastasis. In 2007 Technology Review reported that this device was undergoing clinical trials in lung and prostate cancer. Clinicaltrials.gov lists an ongoing clinical trial with a very similar type of device — possibly the same device or a competing design. The study lists 2012 as the target for completion, so it may be a while before a commercial product is announced.
Microfluidics can be used to study mechanical properties of cells Finally, the Guck group at the University of Cambridge has attacked the problem from the inside, instead looking at the mechanical properties of individual cancer cells. The Guck group has developed a microfluidic optical stretcher to help investigate how the cytoskeleton, cell mechanics, and cell motility may be related, so that we may better understand how to develop therapies that hinder movement of metastatic cells.