Bone is one of the most frequent sites of metastasis in breast cancer, but the exact reasons for this high risk of bone metastases has not been well understood. However, research has found that physics may be partly the reason for this high risk.
A study published in Scientific Reports
found that “metastatic tumor cells are attracted to osteocytes,” which is why these tumor cells can move from the primary tumor site, through the body, and settle into bones.
Researchers at the Indiana University-Purdue University Indianapolis School of Science used a Forster resonance energy transfer-based tension sensor to monitor force dynamics used during cell movement. The sensor was inserted between the head and tail of the vinculin protein. Past research has found that vinculin acts as an inhibitor of tumor migration.
“"From a physics point of view, all the cell migration is driven by force," Jing Liu, an assistant professor in the Department of Physics, explained in a statement
. "We really want to discover the force architecture of a cell and deliver the biomechanical and biophysical explanations toward cellular activities.”
While monitoring the mobility of cancer cells, the researchers found that when a cancer cell gets close to a bone cell and interacts with it, the cancer cell exhibits low tensions and slow mobility. The researchers also found that depletion of the vinculin results in the migration of tumor cells.
The findings provide a more precise measurement of how fast a tumor cell moves and where it goes, Liu said, and shows the impact of treatment on the movement of cells.
"The basic idea is to use imaging as a method to see some of the physical parameters in cancer biology," Liu said. "Instead of only being able to look at millions of cells at time, technology has enabled us to examine a single cell. When the system is going smaller and smaller, the physical parameters inside the biological system become more and more useful and more and more important."
Li F, Chen A, Reeser A, et al. Vinculin force sensor detects tumor-osteocyte interactions. Sci Rep
. 2019;9(1):5615. doi: 10.1038/s41598-019-42132-x.