Fig. 3

miR-155, a modulator of PIK3R1 and FOXO3a protein expression, positively regulate glucose metabolism in human breast cancer cells. a Left: A schematic diagram of the PIK3R1 cDNA with 3′UTR. The predicted miR-155 binding site is indicated as yellow. Light panel: A graph showing luciferase activity of control (empty) or WT or Mutant PIK3R1 UTR (Mut1 or Mut2) reporters. Luciferase reporters were transfected with either scrambled (in blue) or miR-155 mimics (in red). b Left: A schematic diagram of the FOXO3a cDNA with 3′UTR. The predicted miR-155 binding site is indicated as yellow. Light panel: A Graph showing measurement of luciferase activity to confirm whether FOXO3a is a direct target of miR-155. Luciferase constructs containing the 3′UTR of FOXO3a or 3′UTR with point mutations (Mut1 or Mut2) in the miR-155 binding site were transfected with either scrambled (in blue) or miR-155 mimics (in red). (c–e) qRT-PCR results of PIK3R1 (c), FOXO3a (d), and cMYC (e) in human primary breast cancer cells. The human primary breast cancer cells are classified into miR-155 high (PDCH1,2,3) or low (PDCL1,2,3) groups by miR-155 level (See Supplementary Fig 3b). f Western blot results of GLUT1, HK2, PKM2, and LDHA proteins in human primary breast cancer cells used in (c–e). β-ACTIN was used as loading control. g–j Relative glucose-6P (g), glucose (h), pyruvate (i), and NAD (j) levels, measured by LC-MS/MS in miR-155 low control (in blue) or miR-155 over-expressed cells via lentiviral infection (miRH155, in red)