Rotational Movement Discovered in Cells. Spatial organization of cells into ducts and acini (spheres) results in tissue architecture of organs such as lungs, salivary or mammary glands. To do this, cells need to polarize, or preferentially organize in space. Loss of polarity is one of the earliest signs of cancer malignancy.
Mina Bissell’s group at Lawrence Berkeley Labs discovered a new form of cell movement required to form spherical structures. The video shows rotation of cells around a central axis, resulting from centripetal force caused by contraction of crescent shaped actin-myosin complexes (“muscle-like”) in the cytoskeleton. Rotation is slow, about once an hour, may be clockwise or anti-clockwise, and the axis may shift but the motion is cohesive.
Without this movement, “the cells lose their way and do not form structures that allow mammary cells to make and secrete milk,” says lead author Tanner. “In order to form a polarized sphere, the cells have to be properly oriented so that certain components are up and certain components are down.” Cancer cells move randomly, but the authors were able to coax them with inhibitors to revert from their cancer phenotype and form spheres, which has significant implications in breast cancer treatment.
Ref.: Kandice Tanner, et al., Coherent angular motion in the establishment of multicellular architecture of glandular tissues, Proceedings of the National Academy of Sciences, 2012; [DOI: 10.1073/pnas.1119578109] open access