CD271 Defines a Stem Cell-Like Population in Hypopharyngeal Cancer

Cancer stem cells contribute to the malignant phenotypes of a variety of cancers, but markers to identify human hypopharyngeal cancer (HPC) stem cells remain poorly understood. Here, we report that the CD271 + population sorted from xenotransplanted HPCs possesses an enhanced tumor-initiating capability in immunodeficient mice. Tumors generated from the CD271 + cells contained both CD271 + and CD271 − cells, indicating that the population could undergo differentiation. Immunohistological analyses of the tumors revealed that the CD271 + cells localized to a perivascular niche near CD34 + vasculature, to invasive fronts, and to the basal layer. In accordance with these characteristics, a stemness marker, Nanog , and matrix metalloproteinases (MMPs) , which are implicated in cancer invasion, were significantly up-regulated in the CD271 + compared to the CD271 − cell population. Furthermore, using primary HPC specimens, we demonstrated that high CD271 expression was correlated with a poor prognosis for patients. Taken together, our findings indicate that CD271 is a novel marker for HPC stem-like cells and for HPC prognosis.