Detection of unidentified chromosome abnormalities in human neuroblastoma by spectral karyotyping (SKY)

Abstract

Spectral karyotyping (SKY) is a novel technique based on the simultaneous hybridization of 24 fluorescently labeled chromosome painting probes. It provides a valuable addition to the investigation of many tumors that can be difficult to define by conventional banding techniques. One such tumor is neuroblastoma, which is often characterized by poor chromosome morphology and complex karyotypes. Ten primary neuroblastoma tumor samples initially analyzed by G-banding were analyzed by SKY. In 8/10 tumors, we were able to obtain additional cytogenetic information. This included the identification of complex rearrangements and material of previously unknown origin. Structurally rearranged chromosomes can be identified even in highly condensed metaphase chromosomes. Following the SKY results, the G-banding findings were reevaluated, and the combination of the two techniques resulted in a more accurate karyotype. This combination allows identification not only of material gained and lost, but also of breakpoints and chromosomal associations. The use of SKY is therefore a powerful tool in the genetic characterization of neuroblastoma and can contribute to a better understanding of the molecular events associated with this tumor.

Distinct cytogenetic pathways of advanced‐stage neuroblastoma tumors, detected by spectral karyotyping

“…The translocations der(3)t(3; 17) and der(22)t(17;22) appeared as additional secondary translocations to der(11)t(11;17) in 2 of our patients. Similar findings were reported in a cell line (Van Roy et al, 1994 and in fresh tumors (Cohen et al, 2001). Using the CGH technique, 17q gain was detected in 60 -70% of advanced-stage NBL (Lastowska et al, 1997a;Plantaz et al, 1997;Vandesompele et al, 1998;Bown et al, 1999;Hirai et al, 1999;Breen et al, 2000;Janoueix-Lerosey et al, 2000;Plantaz et al, 2001;Vandesompele et al, 2001), similar to findings of the present series.…”

“…This is in contrast to the present series where this translocation was detected in only one patient. We detected der(5)t(5; 17) and der(3)t(3;17) in one patient each, similar to earlier reports in fresh tumors (Meddeb et al, 1996;Cohen et al, 2001). The translocations der(3)t(3; 17) and der(22)t(17;22) appeared as additional secondary translocations to der(11)t(11;17) in 2 of our patients.…”

Polyploidization of Murine Mesenchymal Cells Is Associated with Suppression of the Long Noncoding RNA H19 and Reduced Tumorigenicity

“…Chromosome preparations and spectral karyotyping (SKY) analysis were acquired as previously described (30), and 25 to 75 mitoses were analyzed for each cell line.…”

Preferential Occurrence of Chromosome Breakpoints within Early Replicating Regions in Neuroblastoma

“…1 The specific genetic alterations of NB tumors and cell lines have been explored through a panel of techniques, including Southern blot, FISH, allelotyping, chromosomal CGH (Comparative Genomic Hybridisation) and 24-color or spectral karyotyping. [2][3][4][5][6][7][8][9] Interestingly, these analyses revealed that most rearrangements were unbalanced. At the difference of balanced translocations, which exchange two chromosomal segments, giving rise to two derivative chromosomes without any gain or loss of genetic material, unbalanced translocations replace the distal segment of one chromosome by material from another chromosome.…”