Resistance to the atypical retinoid ST1926 in SK-N-AS cells selected the subline rAS-ST with enhanced sensitivity to ATRA mediated by not conventional mechanisms: DNA damage, G2 accumulation and late telomerase inhibition

•Retinoic acid is successful only in a subset of high-risk neuroblastoma patients.•Retinoic acid-mediated effects are complex and not fully elucidated yet.•Induced resistance to ST1926 in SK-N-AS cells selected a subline sensitive to ATRA.•In the subline ATRA induced G2 block, differentiation and telomerase inhibition.•Sensitivity to ATRA in this subline was mediated by not conventional pathways.