Cells Move in Groups Differently than They Do when Alone
Published:25 Feb.2024 Source:NYU Langone Health / NYU Grossman School of Medicine
A protein that helps generate the force needed for single cells to move works differently in cells moving in groups, a new study shows. Led by researchers at NYU Grossman School of Medicine, the new study examined how forces are generated by a group of 140 cells called the primordium that adhere to each other as they move in zebrafish embryos. To move, cells push out part of themselves called protrusions, use the protrusions to hold on to nearby tissues, and then haul them back in to pull forward, like casting out and hauling in an anchor.
Past studies had shown that single cells move forward in part by activating RhoA at their back ends. But the current study found that the cells in the primordium instead activate RhoA in pulses in the front of the cells where it does two jobs. At the front tip of the cell, RhoA grows the cell skeleton, called the actin meshwork, outward, forming protrusions that grip the surface. At the base of protrusions, RhoA triggers non-muscle myosin II to pull on the actin meshwork and haul in the protrusions. The pulling by myosin II makes the actin flow toward the center and back of the cells, pushing the cell group forward the way a banana slug moves along the ground, but at a different size scale. "Our findings suggest that RhoA-induced actin flow on the basal sides of cells constitutes the motor that pulls the primordium forward, a scenario that likely underlies the movement of many cell groups," added Dr. Knaut.
"The machinery suggests that the movement of single cells and groups of cells is similar, but that RhoA contributes to that machinery differently in each case. Within moving cell groups, RhoA generates actin flow directed toward the rear to propel the group forward." Dr. Knaut notes that a better understanding of the mechanisms by which cell groups move has the potential to be useful in stopping the spread of cancer, perhaps by guiding the design of treatments that block the action of proteins noted in the study.