The Role of Chromosomal Instability and Epigenetics in Colorectal Cancers Lacking β-Catenin/TCF Regulated Transcription

Table 1

Cytogenetic characteristics of RKO cell line compared to MSI and MSS cell lines.

Cell line	Aneuploid Index	Variability of centromere number	Rearranged Chromosomes by M-FISH/SKY	Copy number changes by CGH
RKO	2	1	14	9
MSI cell lines	1–8 (3.1)	1–3 (2)	0–5 (2.7)	0–4 (2.4)
MSS cell lines	8–19 (14.2)	6–30 (15.4)	9–24 (15.8)	11–30 (19.4)

The aneuploid index was calculated as the sum of all the consistent chromosomal gains or losses present in the karyotype. Thus, for each monosomy or each trisomy present, a score of 1 was contributed to the aneuploid index. The aneuploid index is different from the modal chromosome number because of cell to cell variability in the presence or absence of a specific chromosome. The variability of centromere numbers was calculated by counting in each of the examined metaphases the number of copies of each centromere, whether in normal or rearranged copies of a chromosome; noting the percentage of metaphases that have deviations from the modal centromere number; and averaging over all centromeres. The data of the MSS and MSI cell lines, shown as range followed by average, were pooled from the published literature [8, 17, 18] omitting the newest duplicate data in chronological order and excluding the nonclassical cell lines C70, HCA7, and LS411.