Unique breast cancer cells that control their ability to proliferate and colonize lungs, identified

Scientists from The Tisch Cancer Institute have uncovered a mechanism by which certain breast cancer cells regulate their own metastases, fuel dissemination from the original tumor site, and determine routes to invade distant organs such as the lungs, according to a study published in Cell Reports in September.

For the first time, scientists have identified a type of cancer cell in triple negative breast tumors, which is highly efficient in invading and colonizing distant organs but slow their growth upon colonization. These cells have a hallmark of slowed production of a protein called srGAP1, which is usually attributed to cancer growth.

Scientists also found in animal models that these unique cells trigger a phenomenon that keeps them in a dormant state in distant organs such as the lungs. This is an important finding because cancer cells have to efficiently survive at distant sites, and staying in this "asleep" existence allows these cells to evade therapies that target cancer cells' normal rapid growth.

Cells that are missed could later become metastatic.

To conduct this study, researchers used high-resolution in vivo imaging to visualize extravasation, the process of tumor cells exiting the blood vessels to enter a target tissue. This  event was observed in real time, revealing with unprecedented detail the early stages of tumor extravasation. The microscopy studies revealed that after these tumor cells invade the lungs, they enter into a dormant state by secreting the protein TGFβ2. The studies also showed that interfering with that protein can block tumor cell invasion into the lungs.

Reference:

Jose Javier Bravo-Cordero, et al,THE MOUNT SINAI HOSPITAL / MOUNT SINAI SCHOOL OFMEDICINE, JOURNAL:Cell Reports