Breast cancer is becoming increasingly treatable, but in some cases the disease can resurface even decades after a patient has been declared cancer free. This is because of cells that detach from the original tumor and hide in a dormant state in the breast or other organs.
Little is known about the mechanisms responsible for dormancy in cancer cells, and even less is known about what causes these cells to suddenly wake up. A new study from the laboratory of Israel Prize laureate Prof. Yosef Yarden at the Weizmann Institute of Science, published in Science Signaling, reveals the mechanism that puts breast cancer cells to sleep, as well as the reason that they emerge from dormancy more aggressive than they were before they became dormant.
From the earliest stage of embryonic development, through sexual maturation to the production of breast milk during pregnancy and after childbirth, breast tissue changes throughout a woman’s life. These changes are made possible by the metamorphosis that breast tissue cells undergo, from the early developmental stage, known as mesenchymal, when the cells are round, highly mobile and dividing rapidly, to the more mature, epithelial stage, when they are somewhat cubical, less active and dividing slowly.