Identification of copy number abnormalities and inactivating mutations in two negative regulators of nuclear factor-kappaB signaling pathways in Waldenstrom's macroglobulinemia.
Waldenström's macroglobulinemia (WM) is a distinct clinicobiological entity defined as a B-cell neoplasm characterized by a lymphoplasmacytic infiltrate in bone marrow (BM) and IgM paraprotein production. Cytogenetic analyses were historically limited by difficulty in obtaining tumor metaphases, and the genetic basis of the disease remains poorly defined. Here, we performed a comprehensive analysis in 42 WM patients by using a high-resolution, array-based comparative genomic hybridization approach to unravel the genetic mechanisms associated with WM pathogenesis. Overall, 83% of cases have chromosomal abnormalities, with a median of three abnormalities per patient. Gain of 6p was the second most common abnormality (17%), and its presence was always concomitant with 6q loss. A minimal deleted region, including MIRN15A and MIRN16-1, was delineated on 13q14 in 10% of patients. Of interest, we reported biallelic deletions and/or inactivating mutations with uniparental disomy in tumor necrosis factor (TNF) receptor-associated factor 3 and TNFalpha-induced protein 3, two negative regulators of the nuclear factor-kappaB (NF-kappaB) signaling pathway. Furthermore, we confirmed the association between TRAF3 inactivation and increased transcriptional activity of NF-kappaB target genes. Mutational activation of the NF-kappaB pathway, which is normally activated by ligand receptor interactions within the BM microenvironment, highlights its biological importance, and suggests a therapeutic role for inhibitors of NF-kappaB pathway activation in the treatment of WM.
Braggio
Esteban
E
Mayo Clinic, Scottsdale, Arizona 85259-5494, USA.
Keats
Jonathan J
JJ
Leleu
Xavier
X
Van Wier
Scott
S
Jimenez-Zepeda
Victor H
VH
Valdez
Riccardo
R
Schop
Roelandt F J
RF
Price-Troska
Tammy
T
Henderson
Kimberly
K
Sacco
Antonio
A
Azab
Feda
F
Greipp
Philip
P
Gertz
Morie
M
Hayman
Suzanne
S
Rajkumar
S Vincent
SV
Carpten
John
J
Chesi
Marta
M
Barrett
Michael
M
Stewart
A Keith
AK
Dogan
Ahmet
A
Bergsagel
P Leif
PL
Ghobrial
Irene M
IM
Fonseca
Rafael
R
D000483:Alleles; D002869:Chromosome Aberrations; D002882:Chromosomes, Human, Pair 13; D055028:Comparative Genomic Hybridization; D017353:Gene Deletion; D018628:Gene Dosage; D006801:Humans; D019656:Loss of Heterozygosity; D035683:MicroRNAs / Q000235:genetics; D009154:Mutation; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D048008:TNF Receptor-Associated Factor 3 / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D008258:Waldenstrom Macroglobulinemia / Q000235:genetics* / Q000378:metabolism*
C505361:MIRN15 microRNA, human; C505362:MIRN16 microRNA, human; D035683:MicroRNAs; D016328:NF-kappa B; D048008:TNF Receptor-Associated Factor 3; C090656:TRAF3 protein, human; D014409:Tumor Necrosis Factor-alpha