c-myc mRNA expression and genomic alterations in mantle cell lymphomas and other nodal non-Hodgkin's lymphomas.
Cyclin D1 is a weak oncogene that cooperates with c-myc activation in the development of B cell lymphomas in transgenic animals. Cyclin D1 is constantly overexpressed in human mantle cell lymphomas (MCL). However, the status of c-myc gene in these tumors is not known. We have examined the c-myc mRNA expression and genomic alterations, including mutational analysis of exon 1, intron 1, and exon 2 regulatory elements, in a series of 33 MCL, 22 typical and 11 blastoid variants. In addition, c-myc alterations were also examined in 56 nodal non-Hodgkin's lymphomas (NHL). c-myc mRNA overexpression was found in 38% (11/29) of MCL with a slightly higher frequency in blastoid variants (5/10, 50%) than in typical cases (6/19, 31%). Genetic alterations were only found in one blastoid MCL showing a three-fold c-myc gene amplification. In other nodal NHL, c-myc overexpression was found in 24% (7/29) of indolent tumors but in 70% (19/27) of aggressive variants. c-myc Genetic alterations detected in these cases were gene rearrangement and hypermutations in one Burkitt's lymphoma, and individual point mutations in intron 1 or exon 2 in 1/19 (5%) indolent and 7/16 (44%) aggressive variants. These results indicate that c-myc is overexpressed in a subset of MCL, but structural gene alterations are less frequent than in other nodal NHL.
Hernández
L
L
Laboratory of Anatomic Pathology, Hospital Clínic, Institut d'Investigacions Biomédiques 'August Pi i Sunyer' (IDIBAPS), University of Barcelona, Barcelona, Spain.
Hernández
S
S
Beà
S
S
Pinyol
M
M
Ferrer
A
A
Bosch
F
F
Nadal
A
A
Fernández
P L
PL
Palacín
A
A
Montserrat
E
E
Campo
E
E
D015139:Blotting, Southern; D015972:Gene Expression Regulation, Neoplastic; D016259:Genes, myc; D006801:Humans; D020522:Lymphoma, Mantle-Cell / Q000235:genetics*; D008228:Lymphoma, Non-Hodgkin / Q000235:genetics*; D017354:Point Mutation; D018807:Polymorphism, Single-Stranded Conformational; D012333:RNA, Messenger / Q000032:analysis*
D012333:RNA, Messenger