title: Promoter methylation of DAPK1, E-cadherin and thrombospondin-1 in de novo and therapy-related myeloid neoplasms.
abstract: DNA methylation is one of the major epigenetic changes in human cancers, leading to silencing of tumor suppressor genes, with a pathogenetic role in tumor development and progression in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). Methylation of key promoter regions, induced by cytotoxic therapy together with complex genetic changes, is important in the biology of therapy-related myeloid neoplasms (t-MN). We were interested in the characterization of the methylation pattern of AML and MDS de novo and therapy-related. We studied 385 patients (179 females, 206 males), of a median age of 66 years (range 16-98 years). There were 105 MDS, 208 de novo AML and 72 t-MN (45 MDS and 27 AML). Using a methylation-specific PCR, we studied the promoter methylation status of E-cadherin (CDH1), TSP1 and DAP-Kinase 1. These genes have been shown to be involved in the malignant transformation, interfering with angiogenesis, interaction with micro-environment, apoptosis and xenobiotic detoxification. We found no associations between promoter hypermethylation and gender or age at the time of initial diagnosis. In patients with MDS, there were no associations between hypermethylation and clinical characteristics, including IPSS score, WHO classification and cytogenetics. DAPK1 was more frequently methylated in t-MDS/AML when compared to de novo MDS and AML (39% vs 15.3% and 24.4%, p=0.0001), while methylation of CDH1 was similar in t-MDS/AML and AML (51% and 53.4%), but less frequent in de novo MDS (29%) (p=0.003). In the t-MDS/AML group, we found that the methylation pattern appeared to be related to the primary tumor, with DAPK1 more frequently methylated in patients with a previous lymphoproliferative disease (75% vs 32%, p=0.006). On the other hand, methylation of CDH1 was associated to radiotherapy for the primary malignancy (84.5% vs 38%, p=0.003). TSP1 hypermethylation was rare and not characteristic of t-MDS/AML. In 177 patients studied for concurrent methylation of several promoters, t-MN and AML de novo were significantly more frequently hypermethylated in 2 or more promoter regions than de novo MDS (20% vs 12.4%, p<0.001). Chemotherapy and individual genetic predisposition have a role in t-MDS/AML development, the identification of specific epigenetic modifications may explain complexity and genomic instability of these diseases and give the basis for targeted-therapy. The significant association with previous malignancy subtypes may underlie a likely susceptibility to methylation of specific targets and a role for constitutional epimutations as predisposing factors for the development of therapy-related myeloid neoplasm.
authors.affiliation: Istituto di Ematologia, Università Cattolica del Sacro Cuore, Roma, Italy.
authors.forename: Mariangela
authors.initials: M
authors.lastname: Greco
authors.forename: Francesco
authors.initials: F
authors.lastname: D'Alò
authors.forename: Alessandra
authors.initials: A
authors.lastname: Scardocci
authors.forename: Marianna
authors.initials: M
authors.lastname: Criscuolo
authors.forename: Emiliano
authors.initials: E
authors.lastname: Fabiani
authors.forename: Francesco
authors.initials: F
authors.lastname: Guidi
authors.forename: Annalisa
authors.initials: A
authors.lastname: Di Ruscio
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Migliara
authors.forename: Livio
authors.initials: L
authors.lastname: Pagano
authors.forename: Luana
authors.initials: L
authors.lastname: Fianchi
authors.forename: Patrizia
authors.initials: P
authors.lastname: Chiusolo
authors.forename: Stefan
authors.initials: S
authors.lastname: Hohaus
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Leone
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Voso
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD; D051017:Apoptosis Regulatory Proteins; D015820:Cadherins; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D019175:DNA Methylation; D064550:Death-Associated Protein Kinases; D005260:Female; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000378:metabolism*; D016609:Neoplasms, Second Primary / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D019700:Thrombospondin 1
chemical_list: D015703:Antigens, CD; D051017:Apoptosis Regulatory Proteins; C513384:CDH1 protein, human; D015820:Cadherins; D019700:Thrombospondin 1; C579096:DAPK1 protein, human; D064550:Death-Associated Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases