Promotes Immunosuppressive Function of Myeloid-Derived Suppressor Cells in Tumor and Inflammatory Environments.

Myeloid-derived suppressor cells (MDSCs) are major regulators of immune responses in cancer. Both C/EBP homologous protein (CHOP) and C/EBPβ play a critical role in regulating immunosuppressive function of MDSCs. In this study， we identified a novel long noncoding RNA termed as in MDSCs， which may interact with CHOP and the C/EBPβ isoform liver-enriched inhibitory protein. The binding of with both CHOP and the C/EBPβ isoform liver-enriched inhibitory protein promoted the activation of C/EBPβ and upregulated the expression of arginase-1， NO synthase 2， NADPH oxidase 2， and cyclooxygenase-2， which are related to the immunosuppressive function of MDSCs in inflammatory and tumor environments. Additionally， also promoted the enrichment of H3K4me3 on the promoter region of arginase-1， NO synthase 2， NADPH oxidase 2， and cyclooxygenase-2. These findings suggest an important role of in controlling immunosuppressive function of MDSCs in the tumor environment.