Erratum to: PDK1-mTOR signaling pathway inhibitors reduce cell proliferation in MK2206 resistant neuroblastoma cells

Erratum to: Cancer Cell Int (2015) 15:91 DOI 10.1186/s12935-015-0239-4

Unfortunately, the original version of this article [1] contained an error. After publication it came to the authors’ attention that the figure legends were displayed incorrectly. The correct figure legends can be found below in this erratum.

Fig. 1 MK-2206 suppressed the cell growth of NB cells. a MK-2206 suppressed the cell growth of NB cell lines. LAN-1, KP-N-SIFA, NB-19, and SK-N-DZ cells were cultured in RPMI1640 + 10 % FBS with MK-2206 at indicated concentrations. Cell growth was evaluated as cell numbers at 72 h, and it was repeated three times. Data are expressed as the mean (±SD). b Photomicrographs of MK-2206 non-resistant and resistant cells. Cells were cultured in glass bottom slide chambers with RPMI1640 + 10 % FBS, with MK-2206 (resistant sublines)/without MK-2206 (non-resistant cells) overnight. A 50 µm scale is indicated (Olympus Fluoview fv1000, DIC acquisition, ×40). c MK-2206 showed less inhibition in the proliferation of MK-2206-resistant sublines than in the non-resistant cells. Indicated cells were cultured in RPMI1640 + 10 % FBS with MK-2206 at indicated concentrations. Cell growth was evaluated as cell numbers at indicated hours, and it was repeated three times. Data are expressed as the mean (±SD). *P < 0.01

Fig. 2 MK-2206 showed less inhibition in cell growth of MK-2206-resistant sublines. a MK2206 suppressed cell growth in a dose dependent method, and MK-2206-resistant sublines maintained resistance after 2-week withdrawal of MK-2206. Indicated cells were cultured in RPMI1640 + 10 % FBS with MK-2206 at the indicated concentrations. Cell growth was evaluated as cell numbers at 72 h, and it was repeated three times. Data are expressed as the mean (±SD). b IC50 of MK-2206 in indicated cells. c The effect of MK-2206 on cell cycle phase distribution. LAN-1 and LAN-1-MK were treated with/without MK-2206 (5 µM) in RPMI1640 with 10 % FBS for 12 h followed by analysis of cell cycle phase distribution, as introduced in “Methods”. Cells were stained with propidium iodide (PI) for 30 min followed by FACScan flow cytometer. dColumn chart of cell cycle distribution in c

Fig. 3 Effect of GSK2334470 (GSK), PDK1 inhibitor, in MK-2206-resistant sublines compared with non-resistant cells. a Indicated cells were treated with GSK at indicated concentrations, with/without MK-2206 (5 µM) in RPMI1640 + 10 % FBS. Cell growth was evaluated as cell numbers at 72 h, and it was repeated three times. Data are expressed as the mean (±SD). b IC50 of GSK in indicated cells. c The effect of GSK on cell cycle phase distribution in LAN-1 and LAN-MK. LAN-1 and LAN-1-MK were treated with GSK (5 µM) with/without MK-2206 (5 µM) in RPMI1640 with 10 % FBS for 12 h followed by analysis of cell cycle phase distribution, as introduced in “Methods”. Indicated cells were stained with PI for 30 min followed by FACScan flow cytometer

Fig. 4 Effect of AZD8055 (AZD), mTOR inhibitor, in MK2206 resistant sublines compared with non-resistant cells. a Indicated cells were treated with AZD at indicated concentrations, with/without MK-2206 (5 µM) in RPMI1640 + 10 % FBS. Cell growth was evaluated as cell numbers at 72 h, and it was repeated three times. Data are expressed as the mean (±SD). b IC50 of AZD in indicated cells. c The effect of AZD on cell cycle phase distribution in LAN-1 and LAN-MK. LAN-1 and LAN-1-MK were treated with AZD (50 nM) with/without MK-2206 (5 µM) in RPMI1640 with 10 % FBS for 12 h followed by analysis of cell cycle phase distribution, as introduced in “Methods”. Indicated cells were stained with PI for 30 min followed by FACScan flow cytometer

Fig. 5 Effect of GSK2334470 (GSK) on PDK1-mTOR-S6K axis in MK-2206-resistant sublines. a–d After 1 h serum starvation, indicated cells were incubated in RPMI1640 + 10 % FBS with/without MK-2206 (5 µM) or GSK (5 µM). Phosphorylation of PDK1, AKT, mTOR, and S6K were detected by western blot at 1.5 and 12 h, so were AKT and Actin. GSK3β, p-GSK3β and N-MYC were also detected