Detection limits of DNA copy number alterations in heterogeneous cell populations.

Autor: Krijgsman O; Department of Pathology, VU University Medical Center, MB, Amsterdam, The Netherlands., Israeli D, van Essen HF, Eijk PP, Berens ML, Mellink CH, Nieuwint AW, Weiss MM, Steenbergen RD, Meijer GA, Ylstra B
Jazyk: angličtina
Zdroj: Cellular oncology (Dordrecht) [Cell Oncol (Dordr)] 2013 Feb; Vol. 36 (1), pp. 27-36. Date of Electronic Publication: 2012 Nov 02.
DOI: 10.1007/s13402-012-0108-2
Abstrakt: Background: Array Comparative Genomic Hybridization (aCGH) is a widely used technique to assess chromosomal copy number alterations. Chromosomal content, however, is often not uniform throughout cell populations. Here we evaluated to what extent aCGH can detect DNA copy number alterations in heterogeneous cell populations. A systematic evaluation is currently lacking, despite its importance in diagnostics and research. The detection limits reported are a compound of analytical software and laboratory techniques and do not account for the number of probes in relation to sample homogeneity.
Methods: Detection limits were explored with DNA isolated from a patient with intellectual disability (ID) and from tumor cell line BT474. Both were diluted with increasing amounts of normal DNA to simulate different levels of cellularity. Samples were hybridized on microarrays containing 180,880 oligonucleotides evenly distributed over the genome (spacing ~17 kb).
Results: Single copy number alterations, represented by down to 249 probes (4 Mb) and present in 10 % of a cell population, could be detected. Alterations encompassing as few as 14 probes (~238 Kb) could also be detected, but for this a 35 % mosaic level was required.
Conclusions: DNA copy number alterations can be detected in cell populations containing 10 % abnormal cells. Detection of sub-megabase alterations requires a higher percentage of abnormal cells or microarrays with a higher probe density.
Databáze: MEDLINE
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