Some melanoma cancer cells can invade the body

Cells have a cytoskeleton and membrane that separates the high pressure interior of the cell from the lower pressure outside. Sometimes, cracks form in the cytoskeleton. Internal pressure pushes the cell membrane outward, forming a bubble called a vesicle.

By developing a new type of microscope, the team was able to capture this faint form of cell movement, says Danuser, of the University of Texas Southwestern Medical Center in Dallas. Most microscopes hold samples in place with hard surfaces, and this extra pressure can change the behavior of the cells. The team’s new microscope allows a soft gel to surround the cells.

The researchers saw that the flashes “extend and retract about every 20 seconds,” says co-author Meghan Driscoll, a pharmacologist at the University of Minnesota Twin Cities in Minneapolis. “As the hours pass, the balloons are [mechanically] degrading enough material to create a tunnel through which the cell can move.”

Driscoll and colleagues measured increased levels of phosphoinositide 3-kinase — an enzyme involved in cell signaling — near the front of the cells, leading the team to hypothesize that the cells are constantly driven forward by a continuous cycle of vesicle formation and feeling of resistance from the tissues. ahead.

Bubbles can form anywhere in the cell, but only those at the front will meet a surface (those at the back exit into an empty tunnel). Molecular adhesions that act like little feet can then allow the cell to sense the surface of the tunnel and signal where the front is, Danuser says. Then the cell will “enhance balloon formation only where you really need ballooning,” with larger bubbles concentrated toward the direction of travel.

The “mechanically driven kind of reinforcement” that holds the vesicles at the front of the cell is a “fairly new aspect of this work,” says Jeremy Logue, a cancer biologist at Albany Medical College in New York, who was not involved. involved in research. “I think it’s certainly not rated at this level.”