title: Novel pharmacodynamic biomarkers for MYCN protein and PI3K/AKT/mTOR pathway signaling in children with neuroblastoma.
abstract: There is an urgent need for improved therapies for children with high-risk neuroblastoma where survival rates remain low. MYCN amplification is the most common genomic change associated with aggressive neuroblastoma and drugs targeting PI3K/AKT/mTOR, to activate MYCN oncoprotein degradation, are entering clinical evaluation. Our aim was to develop and validate pharmacodynamic (PD) biomarkers to evaluate both proof of mechanism and proof of concept for drugs that block PI3K/AKT/mTOR pathway activity in children with neuroblastoma. We have addressed the issue of limited access to tumor biopsies for quantitative detection of protein biomarkers by optimizing a three-color fluorescence activated cell sorting (FACS) method to purify CD45-/GD2+/CD56+ neuroblastoma cells from bone marrow. We then developed a novel quantitative measurement of MYCN protein in these isolated neuroblastoma cells, providing the potential to demonstrate proof of concept for drugs that inhibit PI3K/AKT/mTOR signaling in this disease. In addition we have established quantitative detection of three biomarkers for AKT pathway activity (phosphorylated and total AKT, GSK3β and P70S6K) in surrogate platelet-rich plasma (PRP) from pediatric patients. Together our new approach to neuroblastoma cell isolation for protein detection and suite of PD assays provides for the first time the opportunity for robust, quantitative measurement of protein-based PD biomarkers in this pediatric patient population. These will be ideal tools to support clinical evaluation of PI3K/AKT/mTOR pathway drugs and their ability to target MYCN oncoprotein in upcoming clinical trials in neuroblastoma.
authors.affiliation: Division of Cancer Therapeutics, The Institute of Cancer Research, London, SM2 5NG, United Kingdom; Division of Clinical Studies, The Institute of Cancer Research, London, SM2 5NG, United Kingdom.
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Smith
authors.affiliation: Division of Clinical Studies, The Institute of Cancer Research, London, SM2 5NG, United Kingdom; Children's and Young People's Unit, Royal Marsden NHS Foundation Trust, Sutton, SM2 5PT, United Kingdom; CNIO, Spanish National Cancer Research Centre, Melchor Fernandez Almagro 3, 28029, Madrid, Spain.
authors.forename: Lucas
authors.initials: L
authors.lastname: Moreno
authors.affiliation: Division of Cancer Therapeutics, The Institute of Cancer Research, London, SM2 5NG, United Kingdom.
authors.forename: Simon P
authors.initials: SP
authors.lastname: Heaton
authors.affiliation: Division of Clinical Studies, The Institute of Cancer Research, London, SM2 5NG, United Kingdom; Children's and Young People's Unit, Royal Marsden NHS Foundation Trust, Sutton, SM2 5PT, United Kingdom.
authors.forename: Louis
authors.initials: L
authors.lastname: Chesler
authors.affiliation: Division of Clinical Studies, The Institute of Cancer Research, London, SM2 5NG, United Kingdom; Children's and Young People's Unit, Royal Marsden NHS Foundation Trust, Sutton, SM2 5PT, United Kingdom.
authors.forename: Andrew D J
authors.initials: AD
authors.lastname: Pearson
authors.affiliation: Division of Cancer Therapeutics, The Institute of Cancer Research, London, SM2 5NG, United Kingdom; School of Biosciences, University of Kent, Canterbury, Kent, CT2 7NJ, United Kingdom. Electronic address: m.d.garrett@kent.ac.uk.
authors.forename: Michelle D
authors.initials: MD
authors.lastname: Garrett
mesh_terms: D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001854:Bone Marrow Cells / Q000378:metabolism* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D000071447:N-Myc Proto-Oncogene Protein / Q000378:metabolism*; D009447:Neuroblastoma / Q000188:drug therapy / Q000378:metabolism*; D010599:Pharmacokinetics; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D000071447:N-Myc Proto-Oncogene Protein; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases; C459801:MYCN protein, human; C546842:MTOR protein, human
keywords: AKT; Biomarker; MYCN; Neuroblastoma; Pharmacodynamic