c-myc overexpression is not mandatory in aggressive-phase multiple myeloma with Burkitt's type translocation.
This report concerns a case of aggressive-phase multiple myeloma (AGMM) with Burkitt's type translocation t(8;14)(q24;q32), detected by Giemsa-banding. Double-color fluorescence in situ hybridization identified the breakpoint on 8q24 at a comparatively centromeric site, which was at least 300 kb and possibly 600 kb distant from the c-myc coding region. The breakpoint on 8q24 of the present case was far removed from that seen in other B-cell neoplasms with t(8;14)(q24;q32). Despite the presence of t(8;14)(q24;q32), neither rearrangement nor overexpression of the c-myc gene was observed in this case. Although our case may be a special case of multiple myeloma, it nevertheless suggests that overexpression of c-myc is not mandatory in an AGMM patient with Burkitt's type translocation. t(8;14)(q24;q32) which was seen in our case represents one of the first to be mapped at more than 300 kb 5' of c-myc. It should also be noted that this result could mean that a centromeric boundary 5' of c-myc exists where the influence of the immunoglobulin (Ig) H enhancer on c-myc transcription is not effective.
Kuroda
J
J
Division of Hematology, Kyoto Second Red Cross Hospital, Japan.
Kimura
S
S
Akaogi
T
T
Hayashi
H
H
Nishida
K
K
Taniwaki
M
M
Kashima
K
K
Abe
T
T
Kobayashi
Y
Y
Kondo
M
M
D000368:Aged; D002883:Chromosomes, Human, Pair 14; D002898:Chromosomes, Human, Pair 8; D005784:Gene Amplification; D015972:Gene Expression Regulation, Neoplastic; D015321:Gene Rearrangement; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D008297:Male; D009101:Multiple Myeloma / Q000235:genetics*; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics*; D014178:Translocation, Genetic
D016271:Proto-Oncogene Proteins c-myc