title: Epigenetic alteration of microRNAs in DNMT3B-mutated patients of ICF syndrome.
abstract: Immunodeficiency, Centromeric region instability, Facial anomalies (ICF; OMIM #242860) syndrome, due to mutations in the DNMT3B gene, is characterized by inheritance of aberrant patterns of DNA methylation and heterochromatin defects. Patients show variable agammaglobulinemia and a reduced number of T cells, making them prone to infections and death before adulthood. Other variable symptoms include facial dysmorphism, growth and mental retardation. Despite the recent advances in identifying the dysregulated genes, the molecular mechanisms, which underlie the altered gene expression causing ICF phenotype complexity, are not well understood. Held the recently-shown tight correlation between epigenetics and microRNAs (miRNAs), we searched for miRNAs regulated by DNMT3B activity, comparing cell lines from ICF patients with those from healthy individuals. We observe that eighty-nine miRNAs, some of which involved in immune function, development and neurogenesis, are dysregulated in ICF (LCLs) compared to wild-type cells. Significant DNA hypomethylation of miRNA CpG islands was not observed in cases of miRNA up-regulation in ICF cells, suggesting a more subtle effect of DNMT3B deficiency on their regulation; however, a modification of histone marks, especially H3K27 and H3K4 trimethylation, and H4 acetylation, was observed concomitantly with changes in microRNA expression. Functional correlation between miRNA and mRNA expression of their targets allow us to suppose a regulation either at mRNA level or at protein level. These results provide a better understanding of how DNA methylation and histone code interact to regulate the class of microRNA genes and enable us to predict molecular events possibly contributing to ICF condition.
authors.affiliation: Institute of Genetics and Biophysics A.B.T., CNR, Naples, Italy.
authors.forename: Sole
authors.initials: S
authors.lastname: Gatto
authors.forename: Floriana
authors.initials: F
authors.lastname: Della Ragione
authors.forename: Amelia
authors.initials: A
authors.lastname: Cimmino
authors.forename: Maria
authors.initials: M
authors.lastname: Strazzullo
authors.forename: Muller
authors.initials: M
authors.lastname: Fabbri
authors.forename: Margherita
authors.initials: M
authors.lastname: Mutarelli
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Ferraro
authors.forename: Alessandro
authors.initials: A
authors.lastname: Weisz
authors.forename: Maurizio
authors.initials: M
authors.lastname: D'Esposito
authors.forename: Maria R
authors.initials: MR
authors.lastname: Matarazzo
mesh_terms: D000015:Abnormalities, Multiple / Q000201:enzymology / Q000235:genetics*; D043171:Chromosomal Instability / Q000235:genetics*; D018899:CpG Islands; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics*; D044127:Epigenesis, Genetic / Q000235:genetics*; D005145:Face / Q000002:abnormalities; D006657:Histones / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000201:enzymology / Q000235:genetics; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D000081207:Primary Immunodeficiency Diseases; D015854:Up-Regulation; D000097584:DNA Methyltransferase 3B
chemical_list: D004248:DNA (Cytosine-5-)-Methyltransferases; D006657:Histones; D035683:MicroRNAs; D000097584:DNA Methyltransferase 3B