Investigators have developed a technique that allowed them to track single tumor circulating in the blood of mice.
The method, described in Chemistry & Biology, involves photoswitchable fluorescent proteins that change color in response to light.
When one laser light hits the circulating tumor cells, they appear to be fluorescent green. A second laser makes the cells appear fluorescent red.
To label cells, the investigators use a violet laser beam aimed at small blood vessels.
The fluorescence from each cell is collected, detected, and reproduced on a computer monitor as real-time signal traces, allowing the team to count and track individual cells in the bloodstream.
“This technology allows for the labeling of just one circulating pathological cell among billions of other normal blood cells by ultrafast changing color of photosensitive proteins inside the cell in response to laser light,” said study author Ekaterina Galanzha, PhD, of the University of Arkansas for Medical Sciences in Little Rock.
In tumor-bearing mice, the investigators could monitor the real-time dynamics of circulating cancer cells released from a primary tumor.
They could also image the various final destinations of individual circulating cells and observe how these cells travel through circulation and colonize healthy tissue, existing sites of metastasis, or the site of the primary tumor.
“Therefore, the approach may give oncologists knowledge on how to intervene and stop circulating cancer cell dissemination that might prevent the development of metastasis,” Dr Galanzha said.
The investigators believe the approach might also prove useful for other areas of medicine—for example, tracking bacteria during infections or immune-related cells during the development of autoimmune disease.
