Early and late effects of pharmacological ALK inhibition on the neuroblastoma transcriptome

// Shana Claeys 1, 2 , Geertrui Denecker 1, 2 , Robrecht Cannoodt 1, 2, 3, 4, 5 , Candy Kumps 1, 6 , Kaat Durinck 1, 2 , Frank Speleman 1, 2 and Katleen De Preter 1, 2 1 Center for Medical Genetics, Ghent University, Ghent, Belgium 2 Cancer Research Institute Ghent, Ghent University, Ghent, Belgium 3 Bioinformatics Institute Ghent From Nucleotides to Networks, Ghent, Belgium 4 Data Mining and Modelling for Biomedicine group, VIB Inflammation Research Center, Ghent, Belgium 5 Department of Respiratory Medicine, Ghent University, Ghent, Belgium 6 Department of Uro-Gynaecology, Ghent University Hospital, Ghent, Belgium Correspondence to: Katleen De Preter, email: Katleen.DePreter@UGent.be Keywords: neuroblastoma; ALK; ALK inhibition; ALK signaling; dynamic Received: July 28, 2017      Accepted: October 17, 2017      Published: November 06, 2017 ABSTRACT Background: Neuroblastoma is an aggressive childhood malignancy of the sympathetic nervous system. Despite multi-modal therapy, survival of high-risk patients remains disappointingly low, underscoring the need for novel treatment strategies. The discovery of ALK activating mutations opened the way to precision treatment in a subset of these patients. Previously, we investigated the transcriptional effects of pharmacological ALK inhibition on neuroblastoma cell lines, six hours after TAE684 administration, resulting in the 77-gene ALK signature, which was shown to gradually decrease from 120 minutes after TAE684 treatment, to gain deeper insight into the molecular effects of oncogenic ALK signaling. Aim: Here, we further dissected the transcriptional dynamic profiles of neuroblastoma cells upon TAE684 treatment in a detailed timeframe of ten minutes up to six hours after inhibition, in order to identify additional early targets for combination treatment. Results: We observed an unexpected initial upregulation of positively regulated MYCN target genes following subsequent downregulation of overall MYCN activity. In addition, we identified adrenomedullin (ADM), previously shown to be implicated in sunitinib resistance, as the earliest response gene upon ALK inhibition. Conclusions: We describe the early and late effects of ALK inhibitor TAE684 treatment on the neuroblastoma transcriptome. The observed unexpected upregulation of ADM warrants further investigation in relation to putative ALK resistance in neuroblastoma patients currently undergoing ALK inhibitor treatment.