Controlling the behavior of cells — including cancers — with light is now possible with engineered cell receptors. To accomplish this, researchers from the Institute of Science and Technology Austria and the Medical University of Vienna linked receptor tyrosine kinases (RTK) — essential cell surface receptors that sense growth factors and hormones — with a light-sensitive protein from yellow-green algae. When signaling molecules bind to RTKs at a cell surface, the two receptors bind to each other in a process called dimerization, which activates signaling in the cell. The engineered RTK were capable of turning on and off signaling within treated cancer and blood endothelial cells, triggering complex cellular programs. Also, the intensity of the light offered precise control of the engineered receptors, the researchers said. In cancer cells, activation of the engineered receptors caused changes in cell morphology, proliferation and gene expression, characteristic of increased cancer malignancy, the researchers said. In blood cells, activation led to cell sprouting, typical of the formation of new blood vessels, the researchers said. The researchers said the optogenetic approach could be used to develop new methods to identify medications. In addition, the signaling process also shows potential for restoring cells associated with degenerative diseases, they said. The research was published in The EMBO Journal (doi: 10.15252/embj.201387695). For more information, visit www.ist.ac.at.