An additional segment at 1p36 derived from der(18)t(14;18) in patients with diffuse large B-cell lymphomas transformed from follicular lymphoma.
The particular translocation in follicular lymphomas (FLs) is a t(14;18)(q32;q21), recombining the immunoglobulin heavy chain (IgH) gene on chromosome 14 with the B-cell leukemia/lymphoma 2 (BCL2) gene on chromosome 18. Some low-grade FLs are aggressively transformed into diffuse large B-cell lymphomas, presumably by acquisition of secondary chromosomal changes, including chromosomal band 1p36. A common example is add(1)(p36). Because it is difficult to identify the origin of add(1)(p36) even on high-resolution G-banding analysis, we used spectral karyotyping (SKY) and double-color fluorescence in situ hybridization (DC-FISH) to define the t(14;18) and the extra band at 1p36 in two cases of diffuse large B-cell lymphoma (DLBCL). SKY revealed that the extra chromosomal segment on 1p36 was derived from chromosome 18. DC-FISH defined BCL2/IgH fusion signals at 1p36 in addition to t(14;18), suggesting that BCL2/IgH fusion at 1p36 was an evolutionary alteration following the primary BCL2/IgH translocation on der(18) in both cases. Our results indicate that IgH alleles, implicated in chromosomal rearrangement, may themselves frequently be targets for secondary translocations, suggesting that multiple IgH translocations and insertions are associated with the progression of FL.
Nomura
Kenichi
K
Molecular Hematology and Oncology, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kawaramachi-Hirokoji, Kyoto, 602-8566, Japan. nomuken@koto.kpu-m.ac.jp
Kanda-Akano
Yumiko
Y
Shimizu
Daisuke
D
Okuda
Takashi
T
Yoshida
Naohisa
N
Matsumoto
Yosuke
Y
Nishida
Kazuhiro
K
Taki
Tomohiko
T
Yokota
Shohei
S
Horiike
Shigeo
S
Taniwaki
Masafumi
M
D002871:Chromosome Banding / Q000379:methods; D020223:Chromosome Painting / Q000379:methods; D002883:Chromosomes, Human, Pair 14 / Q000235:genetics*; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D005260:Female; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007621:Karyotyping / Q000379:methods; D016393:Lymphoma, B-Cell / Q000235:genetics* / Q000473:pathology; D008297:Male; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D014178:Translocation, Genetic
D007143:Immunoglobulin Heavy Chains; D015514:Oncogene Proteins, Fusion; D019253:Proto-Oncogene Proteins c-bcl-2