Molecular cytogenetic analysis of the bladder carcinoma cell line BK-10 by spectral karyotyping

Abstract

The bladder cancer cell line BK‐10 was established from a grade III–IV transitional cell carcinoma (TCC). BK‐10 is near‐tetraploid (±4n) and consists of two subclones with 20–25 structural aberrations. Here we report the cytogenetic analysis of BK‐10 by G‐banding, spectral karyotyping (SKY), and FISH. SKY refers to the hybridization of 24 differentially labeled chromosome painting probes and the simultaneous visualization of all human chromosomes using spectral imaging. SKY enabled us to confirm 12 markers in BK‐10 previously described by G‐banding, redefine 11 aberrations, and detect 4 hidden chromosomal rearrangements, 2 of which had been identified as normal or deleted copies of chromosome 20 and 1 as a normal chromosome 3. Twenty out of 21 translocations identified were unbalanced. FISH analysis of BK‐10 using chromosome arm‐specific paints, centromere probes, and oncogene/tumor suppressor gene‐specific probes revealed a deletion of CDKN2A (p16) in all copies of chromosome 9, a low‐level amplification of MYC (five copies), and loss of one copy of TP53; detected the presence of the Y chromosome in a hidden translocation; and detected four copies of ERBB‐2. A probe set for BCR and ABL verified breakpoints for all translocations involving chromosomes 9 and 22. A new karyotype presentation, “SKY‐gram,” is introduced by combining data from G‐banding, SKY, and FISH analysis. This study demonstrates the approach of combining molecular cytogenetic techniques to characterize fully the multiple complex chromosomal rearrangements found in the bladder cancer cell line BK‐10, and to refine the chromosomal breakpoints for all translocations. Genes Chromosomes Cancer 25:53–59, 1999 Published 1999 Wiley‐Liss, Inc.

Molecular cytogenetic analysis of two primary squamous cell carcinomas of the lung using multicolor fluorescence in situ hybridization

“…SKY has proven to be a powerful technique, complementing existing cytogenetic methods, particularly in characterizing complex karyotypes. The SKY technology has been applied successfully to the analysis of constitutional chromosomal abnormalities [14], cytogenetic alterations in hematological malignancies [12,17], and tumor cell lines [10]. More recently, mFISH has been used to analyze radiation-induced chromosomal aberrations in lymphocytes and hematopoietic progenitor cells [5].…”

Sensitivity of Multiple Color Spectral Karyotyping in Detecting Small Interchromosomal Rearrangements

“…SKY has already demonstrated its diagnostic value in clinical and cancer cytogenetics. Many complex chromosom e rearrangem ents in leukemia and cancer cells have been characterized with this recently developed technology (Coleman et al, 1997;Veldman et al, 1997;Allen et al, 1998;Rao et al, 1998;Sawyer et al, 1998;Zattara-Cannon i et al, 1998;Fleischm an et al, 1999;Padilla-Nash et al, 1999;Rogatta et al, 1999;Rowley et al, 1999;Trakhtenbrot et al, 1999). SKY has also refined the cytogenetic diagnosis for some constitutional chromosomal abnormalities, thereby contributing to the understanding of genotype-phenotype correlations in dysmorphic syndromes Haddad et al, 1998;Huang et al, 1998;Phelan et al, 1998;Reddy et al, 1999).…”

“…The recently developed technology of spectral karyotyping (SKY) allows a simultaneous visualization of all human chromosom es by a single hybridization of 24 differentially labeled chromosom e painting probes and provides a very useful tool for the characterization of the complex chromosome rearrangements in cancer cells Schröck et al, 1996;Coleman et al, 1997;Veldman et al, 1997;Allen et al, 1998;Rao et al, 1998;Sawyer et al, 1998;Zattara-Cannon i et al, 1998;Fleischman et al, 1999;Padilla-Nash et al, 1999;Rogatta et al, 1999;Rowley et al, 1999;Trakhtenbrot et al, 1999) and in de novo constitutional structural abnormalities Haddad et al, 1998;Huang et al, 1998;Phelan et al, 1998;Reddy et al, 1999).…”

Spectral karyotyping analysis of human and mouse chromosomes

“…The systematic analysis of chromosomal abnormalities in cancer cells using SKY allows for the characterization of novel and hidden chromosomal translocations, identification of complex rearrangements 15 and reconstruction of clonal evolution events during cancer progression, and it has revealed the role of unstable chromosome rearrangements, such as jumping translocations, occurring as tissue-specific genomic imbalances 11 . Although SKY allows for the identification of which particular piece of DNA may be contained within a chromosome aberration, the spectral image alone does not provide information as to the specific region of the chromosome localized within a rearrangement.…”