Maria Chiara Fontana

Chromothripsis in acute myeloid leukemia: biological features and impact on survival

Chromothripsis is a one-step genome-shattering catastrophe resulting from disruption of one or few chromosomes in multiple fragments and consequent random rejoining and repair. This study define incidence of chromothripsis in 395 newly-diagnosed adult acute myeloid leukemia (AML) patients from three institutions, its impact on survival and its genomic background. SNP 6.0 or CytoscanHD Array (Affymetrix®) were performed on all samples. We detected chromothripsis with a custom algorithm in 26/395 patients. Patients harboring chromothripsis had higher age (p=.002), ELN high risk (HR) (p<.001), lower white blood cell (WBC) count (p=.040), TP53 loss and/or mutations (p<.001) while FLT3 (p=.025) and NPM1 (p=.032) mutations were mutually exclusive with chromothripsis. Chromothripsis-positive patients showed a worse overall survival (OS) (p<.001) compared with HR patients (p=.011) and a poor prognosis in a COX-HR optimal regression model. Chromothripsis presented the hallmarks of chromosome instability [i.e. TP53 alteration, 5q deletion, higher mean of copy number alteration (CNA), complex karyotype, alterations in DNA repair and cell cycle] and focal deletions on chromosomes 4, 7, 12, 16, 17. CBA. FISH showed that chromothripsis is associated with marker, derivative and ring chromosomes. In conclusion, chromothripsis frequently occurs in AML (6.6%) and influences patient prognosis and disease biology.

SETD2 and histone H3 lysine 36 methylation deficiency in advanced systemic mastocytosis

The molecular basis of advanced systemic mastocytosis (SM) is not fully understood and despite novel therapies the prognosis remains dismal. Exome sequencing of an index-patient with mast cell leukemia (MCL) uncovered biallelic loss-of-function mutations in the SETD2 histone methyltransferase gene. Copy-neutral loss-of-heterozygosity at 3p21.3 (where SETD2 maps) was subsequently found in SM patients and prompted us to undertake an in-depth analysis of SETD2 copy number, mutation status, transcript expression and methylation levels, as well as functional studies in the HMC-1 cell line and in a validation cohort of 57 additional cases with SM, including MCL, aggressive SM and indolent SM. Reduced or no SETD2 protein expression—and consequently, H3K36 trimethylation—was found in all cases and inversely correlated with disease aggressiveness. Proteasome inhibition rescued SETD2 expression and H3K36 trimethylation and resulted in marked accumulation of ubiquitinated SETD2 in SETD2-deficient patients but not in patients with near-normal SETD2 expression. Bortezomib and, to a lesser extent, AZD1775 alone or in combination with midostaurin induced apoptosis and reduced clonogenic growth of HMC-1 cells and of neoplastic mast cells from advanced SM patients. Our findings may have implications for prognostication of SM patients and for the development of improved treatment approaches in advanced SM.

Single Nucleotide Polymorphisms as Genomic Markers for High-Throughput Pharmacogenomic Studies

Genetic variations in patients have strong impact on their drug therapies and responses because the variations may contribute to the efficacy and/or produce undesirable side effects for any given drug. The Drug Metabolizing Enzymes and Transporters (DMET) assay is a high-throughput technology by Affymetrix that is able to simultaneously genotype variants in multiple genes involved in absorption, distribution, metabolism, and excretion of drugs for subsequent clinical applications, i.e., the assay allows for a precise genetic map that can guide therapeutic interventions and avoid side effects.

Targeting WEE1 to enhance conventional therapies for acute lymphoblastic leukemia

BackgroundDespite the recent progress that has been made in the understanding and treatment of acute lymphoblastic leukemia (ALL), the outcome is still dismal in adult ALL cases. Several studies in solid tumors identified high expression of WEE1 kinase as a poor prognostic factor and reported its role as a cancer-conserving oncogene that protects cancer cells from DNA damage. Therefore, the targeted inhibition of WEE1 kinase has emerged as a rational strategy to sensitize cancer cells to antineoplastic compounds, which we evaluate in this study.MethodsThe effectiveness of the selective WEE1 inhibitor AZD-1775 as a single agent and in combination with different antineoplastic agents in B and T cell precursor ALL (B/T-ALL) was evaluated in vitro and ex vivo studies. The efficacy of the compound in terms of cytotoxicity, induction of apoptosis, and changes in gene and protein expression was assessed using different B/T-ALL cell lines and confirmed in primary ALL blasts.ResultsWe showed that WEE1 was highly expressed in adult primary ALL bone marrow and peripheral blood blasts (n = 58) compared to normal mononuclear cells isolated from the peripheral blood of healthy donors (p = 0.004). Thus, we hypothesized that WEE1 could be a rational target in ALL, and its inhibition could enhance the cytotoxicity of conventional therapies used for ALL. We evaluated the efficacy of AZD-1775 as a single agent and in combination with several antineoplastic agents, and we elucidated its mechanisms of action. AZD-1775 reduced cell viability in B/T-ALL cell lines by disrupting the G2/M checkpoint and inducing apoptosis. These findings were confirmed in human primary ALL bone marrow and peripheral blood blasts (n = 15). In both cell lines and primary leukemic cells, AZD-1775 significantly enhanced the efficacy of several tyrosine kinase inhibitors (TKIs) such as bosutinib, imatinib, and ponatinib, and of chemotherapeutic agents (clofarabine and doxorubicin) in terms of the reduction of cell viability, apoptosis induction, and inhibition of proliferation.ConclusionsOur data suggest that WEE1 plays a role in ALL blast’s survival and is a bona fide target for therapeutic intervention. These data support the evaluation of the therapeutic potential of AZD-1775 as chemo-sensitizer agent for the treatment of B/T-ALL.

Abstract 3472: Separase overexpression defines a new subset of acute myeloma leukemia patients characterized by high CD34 and MYC levels

The endopeptidase Separase, encoded by the ESPL1 gene, plays a key role in faithful segregation of sister chromatids by cleaving the cohesin complex at the metaphase to anaphase transition. Its overexpression associates with aneuploidy and bad prognosis in solid tumors. Little is known in Acute Myeloid Leukemia (AML). We profiled the genomic landscape of 405 and 78 AML cases by SNP array (SNP 6.0 and Cytoscan HD, Affymetrix) and whole exome sequencing (100 bp, paired-end, Illumina), respectively. Bone marrow blasts from 61 patients were analyzed by gene expression profiling (HTA 2.0, Affymetrix). Separase expression was determined by Immunohistochemistry (1:600 antibody dilution Abnova, clone 6H6) in 44 AML and 4 control bone marrow specimens. One patient exhibited a nonsynonimous mutation in ESPL1 (1.3%), which was predicted to alter the protein function. Moreover, ESPL1 copy number gain was observed in 5/405 cases (1.2%): 2 hyperdiploid AML, one trisomy 12 and 2 cases with a short gain at 12q. Notably, protein level detection in one of the 12q-gain cases confirmed Separase overexpression. To determine the incidence of Separase overexpression, we performed Immunohistochemistry on additional 43 AML. Separase was overexpressed in 29/44 AML (66%, Separase-high), being comparable to control marrow biopsies in the remaining 15 samples (Separase-low). Sixty-two percent of Separase-high AML were aneuploid. However, no significative association was observed, as previously reported for mutations in the cohesin genes in AML. Separase overexpression correlated with increased patients’ age (median age 64 vs. 57 years, p=.01), 17-fold upregulation of CD34 (p=.004) and a trend towards reduced overall survival (6-years follow-up). Separase overexpression was not mutually esclusive with cohesin gene mutations, it co-occurred with NPM1 and FLT3 lesions and frequent mutations in genes involved in protein post-translational modification and ubiquitination (p=.04). Separase-low cases were enriched for mutations in RAS signaling pathway (NRAS, KRAS, NF1, RIT1, GRAP2, RALGDS; p=4.5x10-5) and in cell migration-related genes (LIMS2, S1PR1, PPIA, PLXNB1, FAT1). Separase-high cases also showed a defined transcriptomic profile, characterized by reduced expression of HOXA/B family genes, the DNA damage repair gene ATM, the p53 regulator MDM2 and forced expression of the cell cycle markers CDC20, AURKB, NUSAP1 and of MYC, independently of chromosome 8 gain. Taken together, our data suggest that genomic lesions targeting ESPL1 are a rare event in AML. However, Separase overexpression is a common feature and defines a new subset of AML cases with a distinct gene expression profile, which may benefit of innovative targeted therapies including CDC20 and bromodomain inhibitors. Supported by: ELN, AIL, AIRC, progetto Regione-Universita 2010-12 (L. Bolondi), FP7 NGS-PTL project. Citation Format: Giorgia Simonetti, Antonella Padella, Simona Righi, Maria Chiara Fontana, Marco Manfrini, Cristina Papayannidis, Giovanni Marconi, Carmen Baldazzi, Marianna Garonzi, Alberto Ferrarini, Massimo Delledonne, Nicoletta Testoni, Elena Sabattini, Giovanni Martinelli. Separase overexpression defines a new subset of acute myeloma leukemia patients characterized by high CD34 and MYC levels [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 3472. doi:10.1158/1538-7445.AM2017-3472

Abstract 2451: Genomic wide microarray analysis identifies novel copy number alterations in adult acute myeloid leukemia

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 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-Universita 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

Abstract 3582: Chromothripsis in AML patients: A new mechanism of cancer initiation and progression

Introduction: Genomic rearrangements can drive the development of cancer through different mechanisms: chromothripsis, a catastrophic mechanism of genomic instability, could be relevant for hematological disease. Aim: To discover the mechanisms underlying the pathogenesis of Acute Myeloid Leukemia (AML), we studied chromothripsis in our cohort of patients (pts). Methods: We perform SNP Array 6.0 or Cytoscan HD Array (Affymetrix) in a cohort of 104 AML pts at diagnosis. SNP Array data were analyzed by Nexus Copy Number™ v7.5 (BioDiscovery). Results: Seven/104 pts (6.7%) showed chromothripsis events involving different chromosomes (8, 17, 11, 5 and 16). These pts had median age of 68.5 years (range 56-76), complex karyotype and high risk disease according to ELN definition. Among the pts showing chromothripsis, we compared chromosomic abnormalities of pts with de novo (5/7) and secondary (2/7) AML. De novo AML showed a prevalence of trisomy of chromosome 8 in a non-statistical way (4/5 vs 0/2), due to the low number of cases. However, we identified significant differences in the pattern of genes altered in the two groups. De novo AML had copy number gain of PEX1, ANK1, NCOA2, ESRP1, TPD52, ESRP1, ZFPM2 and MITF (p Conclusion: Our data suggest that different pathways and genomic alterations are involved in chromothripsis events in de novo and secondary AML, which could be explained by the repeated rounds of stress underwent by leukemic cells in secondary AML cases. Cytoskeleton and microtubules formation pathways appear to be the main cellular processes implicated in chromothripsis genesis, while alterations of histone acetyltransferase, immune response and antigen presentation pathways could sustain leukemic cells after chromothripsis. Acknowledgement: ELN, AIL, AIRC, PRIN, progetto Regione-Universita 2010-12(L. Bolondi), FP7 NGS-PTL project. Citation Format: Maria Chiara Fontana, Viviana Guadagnuolo, Cristina Papayannidis, Giovanni Marconi, Giorgia Simonetti, Antonella Padella, Marco Manfrini, Barbara Santacroce, Margherita Perricone, Silvia Lo Monaco, Emanuela Ottaviani, Simona Soverini, Michele Cavo, Giovanni Martinelli. Chromothripsis in AML patients: A new mechanism of cancer initiation and progression. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3582.

Abstract 368: Specific chromosomic alterations confer therapy resistance in a cohort of 49 patients with newly diagnosed acute myeloid leukemia treated with intensive chemotherapy

Introduction. Intensive induction chemotherapy in non-M3 young Acute Myeloid Leukemia (AML) patients is represented by the association of an antracycline and Cytarabine. Some treatment regimens including fludarabine or the addition of Gemtuzumab Ozogamicin (GO) as a third or fourth drug, proved to give a benefit in terms of CR rates. Aims of the study. In a group of 49 patients treated with intensive chemotherapy, we evaluated chromosomal abnormalities with SNP 6.0 and Cytoscan HD (Affymetrix) in order to improve conventional cytogenetic analysis and discover novel chromosomic aberrations related to clinical data and therapy response. Patients and Methods. From 2001 to 2014, 489 patients were treated in our Institution. Among those, in 49 newly diagnosed AML patients (median age 54 (range 19-71)), SNP microarray based-genotyping were performed and then analyzed by Nexus Copy Number™ v7.5 (BioDiscovery) and R Development Core Team. According to karyotype, FLT3 and NPM1 mutational status, 55.9% of the patients were considered at High Risk (HR) and 4.1% at low risk (LR). Ten patients had secondary AML. Patients were treated with induction schemes including MyFLAI, MyAIE, FLAI, FLAN, FLAG, 3+7 or DAE. Results. The CR rate after induction was 87.8% (43/49 patients). Deaths during induction (DDI), occurring in the first 50 days from 1st line therapy, were 1/49. The median OS was 135 months, the 5-years OS in our patients was 55,1%. Patients treated with GO showed a non-statistical trend toward a better OS than patients treated with other regimens (median OS not reached vs 133 months, respectively). We explored the alterations found by SNP array in our patients searching for novel markers of therapy resistance. We found a median of 192,5 total copy number aberrations (range 72- 1071): a median of 145,5 total copy number aberrations in responding patients group (RPG), and a median of 361 total copy number aberrations (p = ns) in non-responding patients group (NRPG). We compared the frequency of detected aberrations in RPG and in NRPG with Fisher9s exact test. We found that PIK3CA, Gain chr3:178,927,088-178,929,550 (p = 0,0016), SMAD4, Gain chr18:48,573,154-48,573,255 (p = 0,0166) and several other gene9s loci (CASC18, TCF12, UTY, GRB10, ZFY) are significant aberrations in NRPG compared with RPG. Conclusions. We identified a number of genes with significant aberrations in NRPG, particularly PIK3CA, a protein-coding gene involved in cell proliferation and metabolic pathway with interaction with HRAS/KRAS and EGF, and SMAD4, a transcription factor activated by TGF-beta. Those 2 genes were found overexpressed in other solid tumors. We suppose that those genes may be involved in a hyper-proliferative pathway that underlies a mechanism of chemo-resistance. Acknowledgments Work supported by ELN, AIL, AIRC, Progetto Regione-Universit⁁ 2010-12 (L.Bolondi), FP7 NGS-PTL project. Citation Format: Cristina Papayannidis, Maria Chiara Fontana, Giovanni Marconi, Viviana Guadagnuolo, Giorgia Simonetti, Antonella Padella, Simona Soverini, Stefania Paolini, Maria Chiara Abbenante, Sarah Parisi, Chiara Sartor, Silvia Lo Monaco, Marco Manfrini, Elisa Zuffa, Eugenia Franchini, Claudia Venturi, Maria Teresa Bochicchio, Andrea Ghelli Luserna di Rora, Emanuela Ottaviani, Giovanni Martinelli. Specific chromosomic alterations confer therapy resistance in a cohort of 49 patients with newly diagnosed acute myeloid leukemia treated with intensive chemotherapy. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 368.

Abstract 90: A cell cycle-related genomic and transcriptomic signature distinguish aneuploid and euploid acute myeloid leukemia

Chromosome gain or loss, which is the hallmark of aneuploidy, occurs in about 10% of adult Acute Myeloid Leukemia (AML) cases (Farag et al. IJO 2002, Breems et al. JCO 2008), despite inducing a dramatic reduction of cellular fitness in non-malignant cells (Torres et al. Science 2007). The study aimed to identify AML-specific molecular mechanisms having a causative and/or tolerogenic role towards aneuploidy. We performed 100 bp paired-end whole exome sequencing (WES, Illumina Hiseq2000) of 38 aneuploid (A) and 34 euploid (E) AML cases, identified according to cytogenetic analysis and SNP array (CytoScan HD, Affymetrix). Variants were called with GATK, MuTect and VarScan. We also compared the transcriptomic profile of leukemic bone marrow cells from 21 A-AML and 28 E-AML cases (HTA 2.0, Affymetrix). A-AML showed a significantly higher mutation load compared with E-AML (median number of variants: 25 and 15, respectively, p Our data show a link between aneuploidy and genomic instability in AML and highlight novel molecular mechanisms for the acquisition and/or maintenance of the aneuploid phenotype. Deregulation of the cell cycle machinery and DNA damage/repair checkpoints, either through mutations, copy number and transcriptomic alterations, cooperate with leukemogenic pathways, as KRAS signaling, to develop A-AML and overcome the unfitness barrier. This evidence suggests that a number of A-AML patients may benefit from pharmacological reactivation of TP53 and inhibition of KRAS pathway. Supported by: FP7 NGS-PTL project, ELN, AIL, AIRC, PRIN, progetto Regione-Universita 2010-12 (L. Bolondi). Citation Format: Giorgia Simonetti, Antonella Padella, Marco Manfrini, ĺtalo Faria do Valle, Cristina Papayannidis, Carmen Baldazzi, Maria Chiara Fontana, Viviana Guadagnuolo, Anna Ferrari, Elisa Zago, Marianna Garonzi, Simona Bernardi, Annalisa Astolfi, Maria Chiara Abbenante, Giovanni Marconi, Elisa Zuffa, Eugenia Franchini, Ilaria Iacobucci, Michele Cavo, Emanuela Ottaviani, Nicoletta Testoni, Alberto Ferrarini, Massimo Delledonne, Torsten Haferlach, Daniel Remondini, Giovanni Martinelli. A cell cycle-related genomic and transcriptomic signature distinguish aneuploid and euploid acute myeloid leukemia. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 90.

Abstract 4507: New JAK2 heterozygous loss: A role in overall survival in acute myeloid leukemia patients

Acute Myeloid Leukemia (AML) is a clonal hematopoietic disorder characterized by an abnormal proliferation and differentiation of immature blast cells in the bone marrow. SNP microarray approach has resulted in genome-wide screening for genomic alterations with information not previously achievable and also it allows to map all the genes involved in these alterations which may plays a role in oncogenesis. Our objective is to evaluate the prognostic impact of these genetic alterations on clinical outcome. We analyzed 285 AML samples at diagnosis of which 221 by SNP Array 6.0 (Affymetrix) (Affymetrix), while 64 by by CytoScan HD Array (Affymetrix). The results obtained were analyzed by Chromosome Analysis Suite (ChAS) v1.2 (Affymetrix Inc.) and Nexus Copy Number™ v7.5 softwares (BioDiscovery). The 285 AML patients (pts) analyzed are equally distributed between both sexes, they have a median age of 60 years, include miscellaneous cytogenetic abnormalities and normal karyotype. The 44% of pts are treated with chemotherapy (CHT), the 16% of pts with low-dose cytosine arabinoside, the 20% of pts with 5-azacytidine and the 19% of pts are not treated or had only supportive therapy. The ratio between responders and non responders pts was 57/43. Each pt presented an average of 1448 events so distributed: 31% of homozygous deletions, 32% of homozygous amplifications, while irrelevant events are related to heterozygous deletions and amplifications. We also found 36% of uniparental disomy (UPD)events. Among all these macroscopic and submicroscopic alterations, we focused on JAK2 gene, which is located on human chromosome 9 at p24.1 locus. It is composed of 25 exons and encodes a 1132 amino-acid protein of 130.7 kDa. This gene was amplified in 12/285 pts (4%) and deleted in 13/285 (5%). All these pts are treated with CHT but only those characterized by JAK2 deletion are responsive in first line. We showed that the group of pts which present this deletion had a better overall survival rate than the group with the amplification of this gene (p-value The deletion event of JAK2 gene involved two different regions: the first region had a length of 7.429 bp involving the intron 4 and was found in the database genome variant (DGV); the second deletion presented a variable length between different pts: the smallest deleted region had a length of 3342 bp and included the exons 17, 18, 19, while the largest one had a length of 76903 bp which included the portion from exon 9 to exon 19. This second deletion has not been described in DGV and it involved the pseudokinase and kinase domain of JAK2 protein. We have identified Copy Number Variation involving important cancer genes in AML. We have identified a new JAK2 deletion involving its Pseudokinase and Kinase domain and we observed that this deletion of JAK2 correleted with overall survival. ELN, AIL, AIRC, PRIN, progetto Regione-Universita 2010-12 (L. Bolondi), FP7 NGS-PTL project Citation Format: Viviana Guadagnuolo, Maria Chiara Fontana, Cristina Papayannidis, Marco Manfrini, Antonella Padella, Giorgia Simonetti, Anna Ferrari, Giovanni Marconi, Andrea Ghelli Luserna di Rora, Stefania Paolini, MariaChiara Abbenante, Sarah Parisi, Chiara Sartor, Emanuela Ottaviani, Giovanni Martinelli. New JAK2 heterozygous loss: A role in overall survival in acute myeloid leukemia patients. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4507.