Researchers from the Massachusetts Institute of Technology report they have found the mechanism that allows cancer cells to break off the initial tumor site and spread to other parts of the body. Cancer cells are typically anchored in place, but understanding how they break free and migrate, the researchers believe, is the key to uncovering a new approach to cancer treatment.
The researchers report that metastasis is the cause of nearly 90 percent of cancer deaths. Pleural mesothelioma, a cancer of the lining of the lungs caused by past asbestos exposure, is one cancer that is highly aggressive and spreads quickly. The National Cancer Institute reports that treatments for patients with metastatic cancer are to control further growth of the cancer or to relieve symptoms caused by it. In some cases, metastatic cancer treatments may help prolong life. However, according to the NCI, most people who die of cancer die of metastatic disease. Understanding how to stop metastasis is critical for increasing survival in mesothelioma patients.
In a study published Oct. 9 in Nature Communications, MIT researchers reported that proteins called integrins, located on cell surfaces, form the anchors that hold the cells in place. But cells temporarily lose their ability to adhere as they become more metastatic, and the anchors “let go.” The freed cells then move to another area and regain their ability to adhere or stick to tissues, forming another tumor.
“If we can prevent them from growing at these new sites, we may be able to interfere with metastatic disease,” says Sangeeta Bhatia, the John and Dorothy Wilson Professor of Health Sciences and Technology and Electrical Engineering and Computer Science, and leader of the research team.
The authors of the study found that metastatic tumors stuck especially well to fibronectin and galectin-3 proteins that are made of proteins that contain or bind to sugars. This finding, they suggest, can lead to development of new anti-cancer drugs that focus on “a specific protein-protein or protein-sugar interaction, rather than a particular gene mutation.”
The research team is currently developing drugs aimed at inhibiting tumor cell interactions with galectin-3.
2,500 to 3,000 people are diagnosed with mesothelioma each year in the U.S. Mesothelioma takes decades to appear after exposure, but then advances rapidly.