PD-L1 promotes colorectal cancer stem cell expansion by activating HMGA1-dependent signaling pathways.

PD-L1 is critical for tumor cell escape from immune surveillance by inhibiting T cell function via the PD-1 receptor. Accumulating evidence demonstrates that anti-PD-L1 monoclonal antibodies might potently enhance antitumor effects in various tumors, but the effect of PD-L1 on colorectal cancer stem cells (CSCs) remains unclear. We observed high PD-L1 expression in CD133CD44 colorectal CSCs and CSC-enriched tumorspheres.