Researchers at the University of Turku have made a discovery about how cancer stiffness controls the growth of malignant cells.
Many cancer patients discover their disease by finding a “lump”. Cancer induces stiffening of the surrounding tissue, which in turn accelerates the growth of the cancer cells and creates a proliferation-inducing vicious cycle. Academy Professor Johanna Ivaska´s research team at the University of Turku has been studying the mechanosensitivity of normal and tumor tissue. Mechanosensitivity means the ability of cells to sense the stiffness of their surrounding tissue. Many of the human tissues, such as breast tissue, are very soft, and the cells of the tissue have been optimized to grow normally in that specific environment. The cell adhesion receptors, called integrins, transmit signals about the tissue’s softness into the cell’s nucleus and control cellular responses to stiffness via multiple mechanisms.
“New research results prove for the first time that the firmness of the cancerous tumor affects the epigenetic regulation of gene expression and increases the malignancy of the cancer. In a laboratory environment we were able to stop the cancer growth simply by restoring the stiffness of the cancer’s surrounding tissue to match a normal soft breast tissue,” explains Ivaska.
In addition, research results of Research Fellow Riina Kaukonen revealed that increased tissue stiffness induced translocation of an epigenetic enzyme, (JMJD1A) from the cytoplasm to the nucleus and enabled JMJD1A to alter cancer gene expression comprehensively and increased cell growth. By removing the JMJD1A enzyme Kaukonen was able to prevent the growth of various cancer types in vitro and their ability to form cancerous tumors in vivo. In collaboration with doctors from Turku and Helsinki University Hospitals, researchers also discovered that the level of JMJD1A expression was higher in cancers where the tumor’s surrounding tissue displayed markers of higher density.
The research findings were published in Nature Communications on 4 August 2016.
Photo of Johanna Ivaska, Photo: Hanna Oksanen
