Human prostate cancer bone metastases have an actionable immunosuppressive microenvironment.

Bone metastases are devastating complications of cancer. They are particularly common in prostate cancer (PCa), represent incurable disease, and are refractory to immunotherapy. We seek to define distinct features of the bone marrow (BM) microenvironment by analyzing single cells from bone metastatic prostate tumors, involved BM, uninvolved BM, and BM from cancer-free, orthopedic patients, and healthy individuals. Metastatic PCa is associated with multifaceted immune distortion, specifically exhaustion of distinct T cell subsets, appearance of macrophages with states specific to PCa bone metastases. The chemokine CCL20 is notably overexpressed by myeloid cells, as is its cognate CCR6 receptor on T cells. Disruption of the CCL20-CCR6 axis in mice with syngeneic PCa bone metastases restores T cell reactivity and significantly prolongs animal survival. Comparative high-resolution analysis of PCa bone metastases shows a targeted approach for relieving local immunosuppression for therapeutic effect.

Cancer cell. 2021 Oct 15 [Epub ahead of print]

Youmna Kfoury, Ninib Baryawno, Nicolas Severe, Shenglin Mei, Karin Gustafsson, Taghreed Hirz, Thomas Brouse, Elizabeth W Scadden, Anna A Igolkina, Konstantinos Kokkaliaris, Bryan D Choi, Nikolas Barkas, Mark A Randolph, John H Shin, Philip J Saylor, David T Scadden, David B Sykes, Peter V Kharchenko, as part of the Boston Bone Metastases Consortium

Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Stem Cell Institute, Cambridge, MA, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA., Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Stem Cell Institute, Cambridge, MA, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA; Childhood Cancer Research Unit, Department of Women's Health and Children's, Karolinska Institutet, Stockholm, Sweden. Electronic address: ., Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA., Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, USA., St. Petersburg Polytechnical University, St. Petersburg, Russia., Department of Neurosurgery, Harvard Medical School, Boston, MA, USA., Division of Plastic and Reconstructive Surgery, Massachusetts General Hospital, Boston, MA, USA., Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, USA., Harvard Stem Cell Institute, Cambridge, MA, USA; Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA. Electronic address: .