title: Prognostic role of immunohistochemical analysis of 5 mc in myelodysplastic syndromes.
abstract: BACKGROUND
  Aberrant DNA methylation at CpG islands within promoters is increasingly recognised as a common event in human cancers and has been associated with the silencing of important tumour suppressor genes. Epigenetic therapy using hypomethylating agents has demonstrated clinical effectiveness; the drugs azacitidine and decitabine have been approved for the treatment of MDS.
  
  
  METHODS
  We investigated the association between global DNA methylation and clinical outcome in MDS. We evaluated 134 MDS bone marrow trephine biopsies (BMTB) by immunohistochemistry and compared the results with those from an age-matched group of normal BMTB. Immunohistochemistry was performed on paraffin-embedded sections using the anti-5-methylcytosine (5mc) antibody.
  
  
  RESULTS
  Our results showed that the 5mc immunostaining score (M-score) of patients with MDS was higher than those of normal controls and that overall survival significantly correlated with global DNA methylation, age and IPSS score. Therefore, we found that patients with high levels of methylation had a shorter median overall survival (OS) compared with patients with lower levels. These immunohistochemistry results were confirmed by analysing global DNA methylation on LINE-1 sequences using the COBRA method and pyrosequencing.
  
  
  CONCLUSIONS
  This study reports that global DNA methylation detected by immunohistochemistry predicts OS in MDS.
authors.affiliation: Clinica di Ematologia, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica Marche, Ancona, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Poloni
authors.affiliation: Anatomia Patologica, Dipartimento di Neuroscienze, Università Politecnica Marche, Ancona, Italy.
authors.forename: Gaia
authors.initials: G
authors.lastname: Goteri
authors.affiliation: Anatomia Patologica, Dipartimento di Neuroscienze, Università Politecnica Marche, Ancona, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Zizzi
authors.affiliation: Clinica di Ematologia, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica Marche, Ancona, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Serrani
authors.affiliation: Clinica di Ematologia, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica Marche, Ancona, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Trappolini
authors.affiliation: Clinica di Ematologia, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica Marche, Ancona, Italy.
authors.forename: Benedetta
authors.initials: B
authors.lastname: Costantini
authors.affiliation: Clinica di Ematologia, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica Marche, Ancona, Italy.
authors.forename: Marianna
authors.initials: M
authors.lastname: Mariani
authors.affiliation: Clinica di Ematologia, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica Marche, Ancona, Italy.
authors.forename: Attilio
authors.initials: A
authors.lastname: Olivieri
authors.affiliation: Divisione di Medicina, Macerata, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Catarini
authors.affiliation: Divisione di Medicina, Civitanova Marche, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Centurioni
authors.affiliation: Divisione di Oncologia, Camerino, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Alesiani
authors.affiliation: Anatomia Patologica, Dipartimento di Neuroscienze, Università Politecnica Marche, Ancona, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Giantomassi
authors.affiliation: Anatomia Patologica, Dipartimento di Neuroscienze, Università Politecnica Marche, Ancona, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Stramazzotti
authors.affiliation: Anatomia Patologica, Dipartimento di Neuroscienze, Università Politecnica Marche, Ancona, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Biagetti
authors.affiliation: Anatomia Patologica, Dipartimento di Neuroscienze, Università Politecnica Marche, Ancona, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Alfonsi
authors.affiliation: Clinica di Ematologia, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica Marche, Ancona, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Berardinelli
authors.affiliation: Clinica di Ematologia, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica Marche, Ancona, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Leoni
mesh_terms: D044503:5-Methylcytosine / Q000378:metabolism; D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000473:pathology; D001854:Bone Marrow Cells / Q000378:metabolism / Q000473:pathology; D019070:Cell Lineage / Q000235:genetics; D003596:Cytosine / Q000378:metabolism; D019175:DNA Methylation; D005260:Female; D006801:Humans; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics; D008297:Male; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D011379:Prognosis; D017422:Sequence Analysis, DNA
chemical_list: D044503:5-Methylcytosine; D003596:Cytosine
keywords: DNA methylation; hypomethylating agents; immunohistochemistry; myelodysplastic syndromes; pyrosequencing