In this article (), which was published in the October 2011 issue of Cancer Discovery (1), the following errors appear in the Results section. These changes do not affect any of the data presented in the manuscript or the conclusions. The authors regret these errors. The corrected passages are provided below:
Results, page 444, second column, 2nd paragraph:
Erlotinib (10 μM), LY294002 (20 μM), and Akti 1/2 (5 μM) treatment, targeted to block EGFR, PI3K, and Akt signaling respectively, each produced potent suppression of EGF-mediated SREBP-1 cleavage and LDLR expression (Fig. 1F).
EGFRvIII/EGFR signaling promotes LDLR expression through a PI3K/Akt-mediated, SREBP-1–dependent pathway. A, a total of 5 × 105 U87MG and U87MG/EGFRvIII cells were implanted into the flank of immunodeficient SCID/Beige mice. After 21 days, tumors were harvested and immunoblot analysis for p-EGFR, EGFR, p-Akt, and LDLR was performed. M, the mature form of LDLR, which is glycosylated; P, the precursor of LDLR, nonglycosylated. B, U87/EGFRvIII tumors were treated for 7 days with erlotinib (150 mg/kg by oral gavage) and harvested; immunoblot analysis was performed using the indicated antibodies. C, GBM39 cells, a human serially passaged model of endogenous EGFRvIII expression, were implanted in the flanks of SCID mice and treated for 7 days with erlotinib (150 mg/kg by oral gavage). Immunohistochemical analysis of p-EGFR and LDLR was performed. Scale bar, 20 μm. D, Western blot was performed to analyze GBM39 tumor lysates, using indicated antibodies. E, U87/EGFR cells were placed in serum-free medium for 24 hours and stimulated with EGF (20 ng/mL) for the indicated times; then immunoblot analysis was performed using the indicated antibodies. F, effect of the EGFR inhibitor erlotinib (10 μM), the PI3K inhibitor LY294002 (20 μM), the Akt inhibitor Akti-1/2 (5 μM), or the mTORC1 inhibitor rapamycin (1 nM) for 12 hours on SREBP-1 cleavage and LDLR protein levels in U87-EGFR cells. Cells were pretreated with inhibitors for 30 minutes before stimulation with EGF, 20 ng/mL; immunoblot analysis was performed using the indicated antibodies. G, U87/EGFRvIII cells were infected using SREBP-1 shRNA lentivirus for 48 hours at the indicated doses; immunoblot analysis was performed using the indicated antibodies. H, U87/EGFR cells were transfected using SREBP-1 siRNA (10 nM) for 24 hours; then serum-free overnight, cells were stimulated with EGF (20 ng/mL) for 16 hours. Immunoblot analysis was performed using the indicated antibodies. I, shRNA lentiviral knockdown of SREBP-2 had no effect on LDLR levels. Immunoblot analysis was performed using the indicated antibodies. P, the precursor of SREBP-2; C, the C-terminus of SREBP-2.
EGFRvIII/EGFR signaling promotes LDLR expression through a PI3K/Akt-mediated, SREBP-1–dependent pathway. A, a total of 5 × 105 U87MG and U87MG/EGFRvIII cells were implanted into the flank of immunodeficient SCID/Beige mice. After 21 days, tumors were harvested and immunoblot analysis for p-EGFR, EGFR, p-Akt, and LDLR was performed. M, the mature form of LDLR, which is glycosylated; P, the precursor of LDLR, nonglycosylated. B, U87/EGFRvIII tumors were treated for 7 days with erlotinib (150 mg/kg by oral gavage) and harvested; immunoblot analysis was performed using the indicated antibodies. C, GBM39 cells, a human serially passaged model of endogenous EGFRvIII expression, were implanted in the flanks of SCID mice and treated for 7 days with erlotinib (150 mg/kg by oral gavage). Immunohistochemical analysis of p-EGFR and LDLR was performed. Scale bar, 20 μm. D, Western blot was performed to analyze GBM39 tumor lysates, using indicated antibodies. E, U87/EGFR cells were placed in serum-free medium for 24 hours and stimulated with EGF (20 ng/mL) for the indicated times; then immunoblot analysis was performed using the indicated antibodies. F, effect of the EGFR inhibitor erlotinib (10 μM), the PI3K inhibitor LY294002 (20 μM), the Akt inhibitor Akti-1/2 (5 μM), or the mTORC1 inhibitor rapamycin (1 nM) for 12 hours on SREBP-1 cleavage and LDLR protein levels in U87-EGFR cells. Cells were pretreated with inhibitors for 30 minutes before stimulation with EGF, 20 ng/mL; immunoblot analysis was performed using the indicated antibodies. G, U87/EGFRvIII cells were infected using SREBP-1 shRNA lentivirus for 48 hours at the indicated doses; immunoblot analysis was performed using the indicated antibodies. H, U87/EGFR cells were transfected using SREBP-1 siRNA (10 nM) for 24 hours; then serum-free overnight, cells were stimulated with EGF (20 ng/mL) for 16 hours. Immunoblot analysis was performed using the indicated antibodies. I, shRNA lentiviral knockdown of SREBP-2 had no effect on LDLR levels. Immunoblot analysis was performed using the indicated antibodies. P, the precursor of SREBP-2; C, the C-terminus of SREBP-2.
Results, page 445, Figure 1E legend:
The following text was deleted: P, the precursor of SREBP-1; N, the N-terminus of SREBP-1, which is the active form.
The correct text is as follows:
U87/EGFR cells were placed in serum-free medium for 24 hours and stimulated with EGF (20 ng/mL) for the indicated times; then immunoblot analysis was performed using the indicated antibodies.
Results, page 445, Figure 1I legend:
shRNA lentiviral knockdown of SREBP-2 had no effect on LDLR levels. Immunoblot analysis was performed using the indicated antibodies. P, the precursor of SREBP-2; C, the C-terminus of SREBP-2.
In addition, the Western blot in Fig. 1I was mislabeled due to a production error. The corrected panel appears on the next page.
