Fig. 4

HCQ sensitizes NB cells to chemotherapy by inhibition of autophagy. a IGR-N91 and SK-N-SH cells were treated with 15 to 60 μM of HCQ and analyzed for LC3B, p62, mTOR, p-mTOR, AKT, pAKT, Beclin 1 protein expression by immunoblotting. β-actin was used as a loading control. b Cell viability of SK-N-DZ, IGR-N91 and IGR-NB8 was measured using an MTT assay pre and post HCQ treatment (30 μM). c Confocal microscopy analysis was done on transfected IGR-N91 cells with GFP-LC3 not treated or treated 7 h with HCQ 30 μM, vincristine 1 μM or the combination of the two drugs. d Autophagy in SK-N-DZ, IGR-N91 and IGR-NB8 cells was measured by an MDC assay pre and post HCQ treatment (30 μM). e SK-N-DZ cell viability was measured after vincristine or doxorubicin treatment combined or not with HCQ (30 μM). f The autophagic activity of SK-N-DZ cells was measured using a MDC agent after treatment with vincristine or doxorubicin, combined or not with HCQ (30 μM). Results are expressed as percentage of corresponding control and represent mean ± SEM of 4 independent experiments (*: P < 0.05, **: P < 0.01, ***: P < 0.001)