Figure 6.

G-MDSCs promote NEDD9 expression through the NOTCH pathway in esophageal squamous cell carcinoma (ESCC) cells. (A) Expression of NEDD9 was analyzed in KYSE70 before or after co-incubation with G-MDSCs. (B) Capability of tumor sphere formation was measured in ESCC cells with NEDD9 knockdown co-cultured with G-MDSCs. Scale bar = 100 μm. (C) Expressions of KLF4 and ALDH1A3 were analyzed in KYSE70 before or after co-incubation with G-MDSCs. (D–E) Correlations between CD33 and CD271/CD90 expression in 40 ESCC tissues were evaluated by Spearman’s correlation method. (F–G) Correlations between CD33 and CD271/CD90 expression were evaluated in The Cancer Genome Atlas (TCGA; https://cancergenome.nih.gov/) database. Expression of CD33, CD271, and CD90 were obtained from TCGA . All cases were patients with ESCC without any treatment. The correlations in CD33, CD271, and CD90 expression levels were determined by Pearson’s correlation coefficients. (H) Genes in the NOTCH and WNT pathways were analyzed by real-time PCR. (I) Cells were treated with or without a NOTCH inhibitor (RO4929097) and then expression of NEDD9 was detected with or without co-incubation with G-MDSCs. (J) Cells were treated with or without NOTCH inhibitor. The capability of tumor sphere formation was measured with or without co-incubation with G-MDSCs. (K) Cells were treated with or without NOTCH inhibitor (RO4929097). Expression of stemness-related transcription factors CD271 and CD90 was detected. (L) Schematic representation of the working model of the study. *P < 0.05; **P < 0.01.