Spectral karyotype analysis of colon cancer cell lines of the tumor suppressor and mutator pathway.
OBJECTIVE
Microsatellite instability (MSI) is characterized by the size variation of microsatellites in tumor DNA as compared to matching normal DNA due to defects in the mismatch repair system. To examine the chromosomal differences in microsatellite-stable (MSS) and -unstable (MSI) tumors in detail, we analyzed MSS (Caco-2, Colo-205, SW948) and MSI (HCT-15, HCT-116, LoVo) cell lines by spectral karyotyping (SKY).


METHODS
SKY is a sensitive method to detect chromosome aberrations by visualizing each chromosome in a different color. Metaphases were hybridized with a SKY probe mixture. Images were visualized with the SpectraCube system and analyzed with the SKYview imaging software.


RESULTS
The average number of chromosomes was 49 in LoVo, 45 in HCT-116, 46 in HCT-15, 71 in Colo-205, 89 in Caco-2 and 66 in SW-948. Three aberrant chromosomes were detected in LoVo, three in HCT-116, two in HCT-15, seventeen in Colo-205, fourteen in Caco-2 and nine in SW948.


CONCLUSIONS
The karyotypes of MSS colon cancer cells displayed complex numerical and structural aberrations. In contrast the chromosomes of MSI colon cancer cells were mostly unaltered but displayed a few isolated numerical and structural aberrations. We speculate that these isolated aberrations may be specifically involved in the pathogenesis of MSI tumors.
Melcher
R
R
Department of Medicine, University of Würzburg, Germany. r.melcher@medizin.uni-wuerzburg.de
Koehler
S
S
Steinlein
C
C
Schmid
M
M
Mueller
C R
CR
Luehrs
H
H
Menzel
T
T
Scheppach
W
W
Moerk
H
H
Scheurlen
M
M
Koehrle
J
J
Al-Taie
O
O
D002871:Chromosome Banding / Q000379:methods; D002874:Chromosome Mapping; D041322:Chromosomes, Human, Y; D003110:Colonic Neoplasms / Q000235:genetics*; D004273:DNA, Neoplasm / Q000235:genetics / Q000302:isolation & purification; D016147:Genes, Tumor Suppressor; D006801:Humans; D007621:Karyotyping; D008297:Male; D009154:Mutation; D009691:Nucleic Acid Denaturation; D014407:Tumor Cells, Cultured
D004273:DNA, Neoplasm