title: Integrative genomic analysis reveals distinct transcriptional and genetic features associated with chromosome 13 deletion in multiple myeloma.
abstract: OBJECTIVE
  The chromosome 13 deletion (Delta13) is one of the most frequent chromosomal alterations in multiple myeloma (MM). Delta13 is associated with an unfavorable prognosis, although there is increasing agreement that its prognostic relevance must be related to the ploidy status and the presence of different chromosomal translocations. The aim of this study was to provide a comprehensive analysis of the transcriptional features of Delta13 in MM.
  
  
  METHODS
  Highly purified plasma cells from 80 newly diagnosed MM patients were characterized by means of fluorescence in situ hybridization (FISH) and high-density oligonucleotide microarray for gene expression profiling and chromosomal alterations.
  
  
  RESULTS
  We identified 67 differentially expressed genes in the patients with and without the chromosome 13 deletion, all of which were downregulated in the cases with Delta13: 44 mapped along the whole chromosome 13, seven on chromosome 11 and three on chromosome 19. Functional analyses of the selected genes indicated their involvement in protein biosynthesis, ubiquitination and transcriptional regulation. An integrative genomic approach based on regional analyses of the gene expression data identified distinct chromosomal regions whose global expression modulation could differentiate Delta13-positive cases, in particular the upregulation of 1q21-1q42 and the downregulation of 19p and almost the entire chromosome 11. FISH analyses confirmed the close relationship between Delta13-positivity and the presence of extra copies of 1q21-1q42 (p=6 x 10(-4)) or the absence of chromosome 11 and 19 trisomy (p=5 x 10(-4)).
  
  
  CONCLUSIONS
  Our results indicate that distinct types of chromosomal aberrations are closely related to the transcriptional profiles of Delta13-positive cases, suggesting that the contribution of Delta13 to the malignancy should be considered together with associated abnormalities.
authors.affiliation: Centro di Genetica Molecolare ed Espressione Genica, Padiglione G. Marcora, Fondazione IRCCS Ospedale Policlinico, via Francesco Sforza 35, 20122 Milan, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Agnelli
authors.forename: Silvio
authors.initials: S
authors.lastname: Bicciato
authors.forename: Sonia
authors.initials: S
authors.lastname: Fabris
authors.forename: Luca
authors.initials: L
authors.lastname: Baldini
authors.forename: Fortunato
authors.initials: F
authors.lastname: Morabito
authors.forename: Daniela
authors.initials: D
authors.lastname: Intini
authors.forename: Donata
authors.initials: D
authors.lastname: Verdelli
authors.forename: Andrea
authors.initials: A
authors.lastname: Callegaro
authors.forename: Francesco
authors.initials: F
authors.lastname: Bertoni
authors.forename: Giorgio
authors.initials: G
authors.lastname: Lambertenghi-Deliliers
authors.forename: Luigia
authors.initials: L
authors.lastname: Lombardi
authors.forename: Antonino
authors.initials: A
authors.lastname: Neri
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002872:Chromosome Deletion; D002874:Chromosome Mapping; D002882:Chromosomes, Human, Pair 13 / Q000235:genetics*; D005260:Female; D020869:Gene Expression Profiling; D015894:Genome, Human; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D014158:Transcription, Genetic; D015854:Up-Regulation