Researchers have identified a specialized protein that appears to help prevent tumor cells from entering the bloodstream and spreading to other parts of the body. "We have discovered that this protein, TRPM7 (transient receptor potential cation channel subfamily M member 7), senses the pressure of fluid flowing in the circulation and stops the cells from spreading through the vascular system," said Kaustav Bera, a Johns Hopkins University PhD candidate in chemical and biomolecular engineering and a lead author of the study, which was done with colleagues at the University of Alberta and Universitat Pompeu Fabra (Spain). "We found that metastatic tumor cells have markedly reduced levels of this sensor protein, and that is why they efficiently enter into the circulation rather than turning away from fluid flow," said Bera. The findings, published in the July 9, 2021 issue of Science Advances, help shed light on a little-understood part of metastasis called intravasation, when cancer cells that have separated from a primary tumor enter the circulation in order to travel to other parts of the body and establish colonies. The open-access article is titled “The Fluid Shear Stress Sensor TRPM7 Regulates Tumor Cell Intravasation.”