Detection of genomic imbalances in microdissected Hodgkin and Reed-Sternberg cells of classical Hodgkin's lymphoma by array-based comparative genomic hybridization.
BACKGROUND
Cytogenetic analysis of classical Hodgkin's lymphoma is limited by the low content of the neoplastic Hodgkin-Reed-Sternberg cells in the affected tissues. However, available cytogenetic data point to an extreme karyotype complexity. To obtain insights into chromosomal imbalances in classical Hodgkin's lymphoma, we applied array-based comparative genomic hybridization (array comparative genomic hybridization) using DNA from microdissected Hodgkin-Reed-Sternberg cells.


METHODS
To avoid biases introduced by DNA amplification for array comparative genomic hybridization, cHL cases rich in Hodgkin-Reed-Sternberg cells were selected. DNA obtained from approximately 100,000 microdissected Hodgkin-Reed-Sternberg cells of each of ten classical Hodgkin's lymphoma cases was hybridized onto commercial 105 K oligonucleotide comparative genomic hybridization microarrays. Selected imbalances were confirmed by interphase cytogenetics and quantitative polymerase chain reaction analysis and further studied in an independent series of classical Hodgkin's lymphoma.


RESULTS
Gains identified in at least five cHL affected 2p12-16, 5q15-23, 6p22, 8q13, 8q24, 9p21-24, 9q34, 12q13-14, 17q12, 19p13, 19q13 and 20q11 whereas losses recurrent in at least five cases involved Xp21, 6q23-24 and 13q22. Copy number changes of selected genes and a small deletion (156 kb) of the CDKN2B (p15) gene were confirmed by interphase cytogenetics and polymerase chain reaction analysis, respectively. Several gained regions included genes constitutively expressed in cHL. Among these, gains of STAT6 (12q13), NOTCH1 (9q34) and JUNB (19p13) were present in additional cHL with the usual low Hodgkin-Reed-Sternberg cell content.


CONCLUSIONS
The present study demonstrates that array comparative genomic hybridization of microdissected Hodgkin-Reed-Sternberg cells is suitable for identifying and characterizing chromosomal imbalances. Regions affected by genomic changes in Hodgkin-Reed-Sternberg cells recurrently include genes constitutively expressed in cHL.
Hartmann
Sylvia
S
Senckenberg Institute of Pathology, University of Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany. s.hartmann@em.uni-frankfurt.de
Martin-Subero
José I
JI
Gesk
Stefan
S
Hüsken
Julia
J
Giefing
Maciej
M
Nagel
Inga
I
Riemke
Jennifer
J
Chott
Andreas
A
Klapper
Wolfram
W
Parrens
Marie
M
Merlio
Jean-Philippe
JP
Küppers
Ralf
R
Bräuninger
Andreas
A
Siebert
Reiner
R
Hansmann
Martin-Leo
ML
D055028:Comparative Genomic Hybridization; D015894:Genome, Human / Q000235:genetics*; D006689:Hodgkin Disease / Q000145:classification / Q000235:genetics* / Q000601:surgery; D006801:Humans; D042282:Microdissection; D020411:Oligonucleotide Array Sequence Analysis; D016539:Reed-Sternberg Cells / Q000378:metabolism*