How Signals Get Inside Cancer Cells and Spur Aggressive Growth
Source: University of Michigan
Summary: Researchers have found a connection between the cancer cell ‘swallowing’ certain molecules and its ability to activate tumor suppressor genes.
Many cancers develop because of cell signaling problems. Signals must get from outside the cell into its nucleus to produce proteins. If the signal is altered, it alters what the cell makes, which then alters how the cell grows. The outside of a cancer cell is bombarded by signals. They come from the immune system, supporting tissues and other structures. But how do those signals impact cancer? A new study provides a surprising model of the process by which those signals enter and influence the cell. Researchers from the University of Michigan has found a connection between the cancer cell ‘swallowing’ certain molecules and its ability to activate tumor suppressor genes. The finding could open up a potential new avenue to pursue new therapies against cancer. The study findings were published in the Journal of Cell Science.
The team focused on a protein called clathrin, which impacts how metabolites, hormones and other proteins enter into a cell. Clathrin-coated pits form little indentations inwards on the surface of cells that fold in on themselves and internalize these molecules. In this study, they looked at breast cancer cells that did not express PTEN, a protein known to be mutated or deleted in about a third of breast cancers. They found PTEN played a role in the dynamics of clathrin-coated pits. Changing these dynamics by deleting PTEN resulted in shorter-lived pits. This study finds that the short-lived clathrin-coated pits are used to help control the signals that enter the cell. Additionally, PTEN alters the signaling of the clathrin-coated pits that make cancer more aggressive.
Prof. Sofia Merajver said, “This finding opens a new view to the potential role of PTEN on how cancers modulate the outside world and how aggressive they get. It potentially opens new lines of thinking about how to attack the cancer and prevent it from becoming more aggressive.”
More Information: Luciana K. Rosselli-Murai et al, “Loss of PTEN promotes formation of signaling-capable clathrin-coated pits”, Journal of Cell Science (2018). DOI: 10.1242/jcs.208926