CD200: Association with cancer stem cell features and response to chemoradiation in head and neck squamous cell carcinoma

ABSTRACT Background The purpose of this study was to characterize the expression of CD200, a membrane protein that functions in immune evasion, to examine its correlations with cancer stem cell (CSC)‐like features and analyze its response to chemotherapy and radiation in human papillomavirus (HPV)‐positive (+) and negative (−) head and neck squamous cell carcinomas (HNSCCs). Methods CD200 expression was analyzed in several HNSCC cell lines. CD200 was overexpressed in HPV(+) murine tonsil epithelial cells, its effects on Shh and Bmi‐1 were examined in vitro, and tumor growth and response to chemoradiation were analyzed in vitro and in vivo. Results CD200 was diversely expressed and consistently associated with expression of Bmi‐1 and Shh. Overexpression of CD200 induced Bmi‐1 and Shh. Tumors grew similarly between C57BL/6 and Rag1‐/‐ C57BL/6 mice. CD200 expression enhanced the resistance to chemoradiation only in vivo. Conclusion CD200 was related to CSC features and modulates response to chemoradiation in vivo. Attenuating this might be a potential therapeutic strategy. © 2014 Wiley Periodicals, Inc. Head Neck, 37: 327–335, 2015