Researchers at Baylor College of Medicine and collaborating institutions have developed a method that reveals the cellular makeup of tissues that support metastatic cancer growth, which is the primary cause of death for most patients with solid tumors. The technique, sortase A-based microenvironment niche tagging (SAMENT), is designed to selectively label cells encountered by cancer cells during metastasis. The team’s tests using SAMENT not only revealed cellular features shared by metastatic niches of multiple cancer models but also uncovered an unexpected driver of immune suppression in bone metastasis. “As tumors progress, cancer cells leave the original site and spread or metastasize to other organs where they seed new tumors,” said Xiang Zhang, PhD, William T. Butler, MD, Endowed Chair for Distinguished Faculty, professor of molecular and cellular biology, and director of the Lester and Sue Smith Breast Center at Baylor. “Our lab is interested in better understanding what cellular and molecular features support metastasis as these could guide the development of therapies to prevent, slow down, or eliminate them. In the current study, we first developed a new method to identify the makeup of metastatic niches.” Zhang, also a member of Baylor’s Dan L Duncan Comprehensive Cancer Center, is senior and corresponding author of the team’s published paper in Cell, titled “Unbiased niche labeling maps immune-excluded niche in bone metastasis.” During metastasis, cancer cells interact constantly with other normal cells in the body, and these interactions affect cell behavior, fate, and even response to therapies. “Numerous previous studies have elucidated…