CD200 in Human Breast Cancer

Researchers: Co-Principal Investigators: D.A. Clark & B. Dhesy
Co-Investigator: J. Ramsay

Dhesy

Bindi Dhesy

clark

David Clark

Status: Funded 2011
Study closed to accrual- 30 patients accrued.
It has been recognized that an established tumor is able to shut down immune rejection cells so they can’t work. A molecule called CD200 appears to be very important in this shut down process. CD200 is expressed on stem cells. All tissues in the body develop from stem cells. When a genetic change occurs in a stem cell, it may become malignant and give rise to a collection of more developed cells recognized as a cancer, and many of these cells do not express CD200. However, as long as CD200 is present, the stem cell can evade rejection. Chemotherapy is most effective when aided by an immune response, but killing the last cell requires eradicating cancer stem cells. Over time, more and more genetic changes in stem cells enable the tumor to metastasize to different organs, and resist chemotherapy. In this project, tumor tissues removed at surgery are stained for CD200+ cells, to see if tumors with a large percentage of these cells are more aggressive. CD200+ cells can also protect CD200- tumor cells from rejection by releasing CD200 in soluble form into surrounding tissues and the blood stream. Thirty study participants consented to the study and investigators found greater CD200 staining in those with larger tumours. CD200 staining did not correlate with the presence of lymph node metastases. Eventually, we hope to predict which women will benefit most from a new monoclonal antibody to human CD200. The study results were published in the American Journal of Reproductive Immunology in 2014.