Fig. 4

DCLK1 activates IL-6/JAK1/STAT3 signaling. a Gene set variation analysis (GSVA) showing DCLK1-associated pathways in TNBC. b Gene set enrichment analysis (GSEA) revealing the significant activation of IL-6/JAK/STAT3 pathway in DCLK1-high expressed TNBC patients. c Spearman correlation analysis showing the positive association between DCLK1 expression and IL6 expression. d, e Western blotting to determine expression levels of phosphorylated STAT3 (Tyr705) and total STAT3 as well as CSC-associated markers (d) and EMT-associated markers (e) in TNBC cells treated with exogenous IL-6 stimulation for 24 h. f TIDE analysis showing a lower response in TNBC patients with a higher IL-6 expression (left, 21%, 38/180) than patients with a lower IL-6 expression (right, 32%, 58/122) in the FUSCC dataset. g CFSE-based T-cell proliferation assay revealing a lower activity of CD8+ T cell treated with exogenous IL-6 stimulation for 72 h compared to the control group. h Real-time qPCR determination of the effects of DCLK1 on IL-6 mRNA expression levels. i Western blotting detection of activated IL-6/JAK1/STAT3 signaling in DCLK1-overexpressing MDA-MB-468 cells (left) and inactivated IL-6/JAK1/STAT3 signaling in DCLK1-knockout BT549 cells (middle), 4T1 cell (right). j IHC examination of DCLK1, IL-6, phosphorylated STAT3 (Tyr705) and CD8 in the control and DCLK1-knockout 4T1 subcutaneous tumors