B7H1 expression and epithelial-to-mesenchymal transition phenotypes on colorectal cancer stem-like cells

Abstract

Cancer stem cells (CSCs) can invade and metastasize by epithelial-to-mesenchymal transition (EMT). However, how they escape immune surveillance is unclear. B7H1 is crucial negative co-stimulatory molecule but little information about whether it works in CSCs. Therefore, we determined the expression of B7H1 and EMT-associated markers in colorectal cancer stem-like cells to investigate a possible immunoevasion way of CSCs. We enriched CD133 + colorectal cancer cells which manifested the CSCs-like properties such as higher levels of other stem cell markers Oct-4 and Sox-2, tumor sphere forming ability and more tumorigenic in NOD/SCID mice. These CD133 + cells possess EMT gene expression profile including higher level of Snail, Twist, vimentin, fibronectin and lower level of Ecadherin. Moreover, CD133 + cells in both cell line and colorectal cancer tissues expressed high level of negative co-stimulate molecule B7H1. Furthermore, some B7H1 + cancer cells also showed the characteristic of EMT, indicating EMT cells could escape immune attack during metastasis. B7H1 expression and EMT phenotypes on CSCs indicates a possible immunoevasion way. Copyright: