Fig. 4

NEAT1-mediated miR-361 suppression augments metastatic phenotypes and induces chemoresistance through STAT3 pathway activation. (a) The putative binding site of miR-361 in the STAT3 3′-UTR. (b) Luciferase reporter assay with SPAC-1-L cells cotransfected with a luciferase reporter plasmid containing wild-type (wt) or mutant (mt) STAT3 and miR-361 mimic (mi) or miR-361 inhibitor (in). (c) Western blot analysis of the indicated proteins in SPAC-1-L cells overexpressing miR-361 or HI cells with miR-361 expression knockdown. (d) Left panel: The protein expression of STAT3 in EM, SPAC-1-L and HI cells detected using Western blot analysis (upper). The protein expression of STAT3 and p-STAT3 in SPAC-1-L cells treated with or without the STAT3 inhibitor BP-1-102 (bottom). Right panel: Western blot analysis of the indicated proteins in SPAC-1-L cells cotransfected with control or miR-361 mimic with or without a STAT3 expression vector (vec). (e) Cell invasion and sphere formation abilities of SPAC-1-L cells treated with or without BP-1-102. (f) Cell invasion and sphere formation abilities of SPAC-1-L cells cotransfected with control or miR-361 mimic with or without a STAT3 expression vector. (g) Cell survival examined by a cell viability assay in SPAC-1-L and HI cells cotransfected with a control or miR-361 mimic with or without a STAT3 expression vector and treated with TX. (h, i) Cell invasion, sphere formation and drug sensitivity of control or NEAT1-silenced SPAC-1-L (h) and HI (i) cells transfected with or without a STAT3 expression vector. (j) Cell survival examined by a cell viability assay in control or NEAT1-silenced SPAC-1-L and HI cells transfected with or without a STAT3 expression vector and treated with TX. *P < 0.05