Abstract 2451: Genomic wide microarray analysis identifies novel copy number alterations in adult acute myeloid leukemia
Authors: Fontana Maria Chiara , Marconi Giovanni , Papayannidis Cristina , Fonzi Eugenio , Simonetti Giorgia , Padella Antonella , Ferrari Anna , Ottaviani Emanuela , Monaco Silvia Lo , Paolini Stefania , Soverini Simona , Martinelli Giovanni 
Published: July 2017

Introduction: Novel array-based technique as SNP microarray can detect losses or gains of chromosomic material, which could be predictive of response and can help define therapeutic strategies. The aim of this study is to improve conventional cytogenetic analysis and identify new genetic alterations relevant to leukemogenesis, by a SNP array-based genotyping approach.

Materials and Methods: We performed SNP 6.0 or Cytoscan HD (Affymetrix) in 235 Acute Myeloid Leukemia (AML) patients at diagnosis. Seventy-eight/235 samples were also performed by Whole Exome Sequencing, WES (HiSeq,Illumina). SNP Array data were analyzed by Nexus Copy Number v8.0 (BioDiscovery) and R Core Team.

Results: Copy Number Alterations (CNAs) were scattered across all chromosomes and all pts showed CNA events. SNP array analysis showed that several genes were preferentially deleted, including MRPS5 (14.8%), PHF6 (9.3%), SCAPER (7.2%), CASK (5.9%), WNK (4.6%), STAG2 (4.2%), LRRK1 (3.4%), PALB2 (3.4%), while the genes preferentially amplified were RABL2B (16.1%), NF2 (10.2%), NBPF9 (7.6%), JAK2 (6.8%), RB1, NF1 and KMT2A (4.2%), PTEN (3.4%), TP73 and SMAD2 (2.5%). Single-copy losses and deletions were enriched (p&lt;.001) for genes mapping into the following pathways: aberrant PD-1 signaling, loss of function of SMAD4 in cancer and SMAD4 MH2 Domain mutants in cancer. The functional pathways significantly (p&lt;.001) deregulated in our cohort with single copy gain and homozygous amplification were: regulation of transcription and nucleic acid, negative regulation of metabolic processes, constitutive signaling by aberrant PI3K in cancer and PI3K/AKT network. Finally, in order to define driver alterations, we correlate deletions and losses with mutational data. Interestingly, we found losses which are also targeted by mutations (BRCA2, LRRK1). Moreover, some deleted genes, as CASK, CDK6 and MAPT, were involved in pathways affected by genomic mutations (CASK deletion and MPP6 mutation, CDK6 deletion and PPM1D mutation, MAPT deletion and SPAG5 mutation).

Conclusion: We have identified new CNAs and pathways involving novel potential leukemia-related genes. Our results suggest that the comparison between SNP and WES data could provide important findings on prognosis of AML patients. Minimal deleted regions of genes implicated in deregulated pathways deserve further investigation in order to identify new candidate genes which could be relevant AML biomarkers. Acknowledgements: ELN,AIL,AIRC,progetto Regione-Università 2010-12 (L. Bolondi),FP7 NGS-PTL project,HARMONY.

Citation Format: Maria Chiara Fontana, Giovanni Marconi, Cristina Papayannidis, Eugenio Fonzi, Giorgia Simonetti, Antonella Padella, Anna Ferrari, Emanuela Ottaviani, Silvia Lo Monaco, Stefania Paolini, Simona Soverini, Giovanni Martinelli. Genomic wide microarray analysis identifies novel copy number alterations in adult acute myeloid leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2451. doi:10.1158/1538-7445.AM2017-2451