title: Heterogeneous pattern of chromosomal breakpoints involving the MYC locus in multiple myeloma.
abstract: Chromosomal rearrangements of the MYC locus, which often involve the IG loci, are recurrent events in multiple myeloma (MM) and plasma cell leukemia (PCL). We used dual-color fluorescence in situ hybridization (FISH) to characterize the breakpoint locations of chromosomal translocations/rearrangements involving the MYC locus at 8q24 found in a panel of 14 MM cell lines and 70 primary tumors (66 MM and 4 PCL). MYC locus alterations were observed in 21 cases: MYC/IG (mainly IGH@) fusions in 11 cell lines and three patients (2 MM and 1 PCL), and extra signals and/or abnormal MYC localizations in seven patients (5 MM and 2 PCL). Fourteen of these cases were investigated by FISH analyses by use of a panel of BAC clones covering about 6 Mb encompassing the MYC locus. The breakpoints were localized in a region 100-250 kb centromeric to MYC in four cases, a region 500-800 kb telomeric to the gene in four cases, and regions > or = 2 Mb centromeric or telomeric to MYC in five cases. Two different breakpoints were detected in the KMS-18 cell line, whereas the insertion of a MYC allele was found in a complex t(16;22) chromosomal translocation in the RPMI8226 cell line. Our data document a relatively high dispersion of 8q24 breakpoints in MM.
authors.affiliation: Laboratorio di Ematologia Sperimentale e Genetica Molecolare, U.O. Ematologia 1, Dipartimento di Scienze Mediche, Università degli Studi di Milano, Ospedale Maggiore IRCCS, Italy.
authors.forename: Sonia
authors.initials: S
authors.lastname: Fabris
authors.forename: Clelia Tiziana
authors.initials: CT
authors.lastname: Storlazzi
authors.forename: Luca
authors.initials: L
authors.lastname: Baldini
authors.forename: Lucia
authors.initials: L
authors.lastname: Nobili
authors.forename: Luigia
authors.initials: L
authors.lastname: Lombardi
authors.forename: Anna Teresa
authors.initials: AT
authors.lastname: Maiolo
authors.forename: Mariano
authors.initials: M
authors.lastname: Rocchi
authors.forename: Antonino
authors.initials: A
authors.lastname: Neri
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002461:Cell Line, Transformed; D019457:Chromosome Breakage / Q000235:genetics*; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics; D005260:Female; D015321:Gene Rearrangement / Q000235:genetics; D016259:Genes, myc / Q000235:genetics*; D018740:Genetic Heterogeneity; D005819:Genetic Markers / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000235:genetics* / Q000473:pathology; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D014178:Translocation, Genetic / Q000235:genetics; D014407:Tumor Cells, Cultured
chemical_list: D005819:Genetic Markers; D015514:Oncogene Proteins, Fusion