Laminin-111 and the Level of Nuclear Actin Regulate Epithelial Quiescence via Exportin-6

N-actin levels control transcription and proliferation of normal mammary cells. Here, the authors show that laminin 111 (LN111) induces a drastic decrease of nuclear actin in human mammary epithelial cells in a process mediated by XPO6 and required for the acquisition of cellular quiescence. LN1111 attenuates PI3K, leading to the upregulation of XPO6 activity. The LN111/XPO6/N-actin pathway is abnormal in malignant cells that are unresponsive to LN111 and proliferate uncontrollably.