Researchers reveal how migrating tumour cells produce protein that helps set up home in bones

Migrating tumour cells produce a protein that aids them to set up home in bones, as University of Freiburg researchers show
Cancer cells that migrate to the bone acquire a unique trait: They start to express the protein cathepsin K. Researchers from the University of Freiburg and the BIOSS Centre for Biological Signalling Studies have now solved why it is important for the migrating cells to produce this protein. Polymer chemist Prof. Dr. Prasad Shastri and the pharmacist Jon Christensen discovered that cathepsin K activates another protein, which helps the cancer cells to alter their microenvironment so that they are able to develop into tumours. The researchers published their findings in a paper in the open access journal BMC Research Notes.
If a tumour develops metastases, the chances of the patient’s survival will be severely diminished. Cancer cells that leave the primary tumour, travel through the body, and set up home in distal organs such as lungs and bones start to express cathepsin K. Cathepsin K is primarily found only in the bone and is secreted by osteoclasts. These cells resorb bone tissue to maintain, repair, and remodel the bone. Why it is important for migrating cancer cells to produce cathepsin K has remained a mystery, however.