CD133 Regulates IL-1β Signaling and Neutrophil Recruitment in Glioblastoma

CD133, a pentaspan transmembrane glycoprotein, is generally used as a cancer stem cell marker in various human malignancies, but its biological function in cancer cells, especially in glioma cells, is largely unknown. Here, we demonstrated that forced expression of CD133 increases the expression of IL-1β and its downstream chemokines, namely, CCL3, CXCL3 and CXCL5, in U87MG glioma cells. Although there were no apparent changes in cell growth and sphere formation in vitro and tumor growth in vivo, in vitro trans-well studies and in vivo tumor xenograft assays showed that neutrophil recruitment was markedly increased by the ectopic expression of CD133. In addition, the clinical relevance between CD133 expression and IL-1β gene signature was established in patients with malignant gliomas. Thus, these results imply that glioma cells expressing CD133 are capable of modulating tumor microenvironment through the IL-1β signaling pathway.