The stabilized NF90 by the reduced lncRNA-LET is required for cancer cell stemness. (A) Western blotting showing NF90 protein level in T24 with depletion of lncRNA-LET and J82 cells with overexpression of lncRNA-LET. (B) Protein level of NF90 in J82 cells over-expressed lncRNA-LET, followed by 50 μg/ml cycloheximide (CHX) treatment for the indicated time points. (C-D) ALDHhigh population (C) and expression of CSC markers (D) were determined by flow cytometer and Western blotting in control (siNC), lncRNA-LET knockdown (siLET#2), and simultaneous knockdown lncRNA-LET and NF90 (siLET#2 + siNF90#1 or siLET#2 + siNF90 #2) of T24 cells (n=3 per group). (E) Protein level of NF90 was determined by Western blotting in untreated and GEM resistant T24 cells. (F) The ALDHhigh population was determined by flow cytometer in control (siNC) and NF90 knockdown (siNF90 #1 and #2) T24 cells treated with or without GEM. (G) Western blotting showing the levels of CSC markers in control (siNC) and NF90 knockdown (siNF90 #1 and #2) T24 cells, followed by the treatment with or without GEM. Data are shown as mean ± SD and represent at least two independent experiments with similar results. * P < 0.05, ** P < 0.01, *** P < 0.001 (Student's unpaired two-tailed t-test).