(A) No changes on GLUT1 expression were detected by knocking down EGFR, but SGLT1 was downregulated to an undetectable level. β-actin served as a loading control.
(B) Cells treated with SGLT siRNA led to downregulation of SGLT1 after 4 days of culture in MEM.
(C) This treatment also led to a significant proportion of cell deaths (p < 0.01) as evidenced by the presence of sub-G1 cells (arrow), and hgMEM was able to prevent cells from death. (The flow cytometry data of control vector-transfected cells were similar to those of the control cells used in the EGFR siRNA experiment in Figure 2.)
(D) As with the EGFR siRNA-treated cells, cells that underwent SGLT1 siRNA treatment also showed a large amount of autophagosomes (arrows) on transmission electron microscopy (bar, 2 μm).