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Hôpital-Camfrout, France

Cosson A.,French Institute of Health and Medical Research | Chapiro E.,French Institute of Health and Medical Research | Chapiro E.,University Pierre and Marie Curie | Belhouachi N.,Service dhematologie biologique | And 35 more authors.
Genes Chromosomes and Cancer

Deletions of the long arm of chromosome 14 [del(14q)] are rare but recurrently observed in mature B-cell neoplasms, particularly in chronic lymphocytic leukemia (CLL). To further characterize this aberration, we studied 81 cases with del(14q): 54 of CLL and 27 of small lymphocytic lymphoma (SLL), the largest reported series to date. Using karyotype and fluorescence in situ hybridization (FISH), the most frequent additional abnormality was trisomy 12 (tri12), observed in 28/79 (35%) cases, followed by del13q14 (12/79, 15%), delTP53 (11/80, 14%) delATM (5/79, 6%), and del6q21 (3/76, 4%). IGHV genes were unmutated in 41/53 (77%) patients, with a high frequency of IGHV1-69 (21/52, 40%). NOTCH1 gene was mutated in 14/45 (31%) patients. There was no significant difference in cytogenetic and molecular abnormalities between CLL and SLL. Investigations using FISH and SNP-array demonstrated the heterogeneous size of the 14q deletions. However, a group with the same del(14)(q24.1q32.33) was identified in 48% of cases. In this group, tri12 (P=0.004) and NOTCH1 mutations (P=0.02) were significantly more frequent than in the other patients. In CLL patients with del(14q), median treatment-free survival (TFS) was 27 months. In conclusion, del(14q) is associated with tri12 and with pejorative prognostic factors: unmutated IGHV genes (with over-representation of the IGHV1-69 repertoire), NOTCH1 mutations, and a short TFS. © 2014 Wiley Periodicals, Inc. Source

Havelange V.,Catholic University of Louvain | Pepermans X.,Catholic University of Louvain | Ameye G.,Catholic University of Louvain | Theate I.,Catholic University of Louvain | And 12 more authors.
British Journal of Haematology

Dysregulation of MYC is the genetic hallmark of Burkitt lymphoma (BL) but it is encountered in other aggressive mature B-cell lymphomas. MYC dysregulation needs other cooperating events for BL development. We aimed to characterize these events and assess the differences between adult and paediatric BLs that may explain the different outcomes in these two populations. We analysed patterns of genetic aberrations in a series of 24 BLs: 11 adults and 13 children. We looked for genomic imbalances (copy number variations), copy-neutral loss of heterozygosity (CN-LOH) and mutations in TP53, CDKN2A, ID3 (exon 1), TCF3 (exon17) and CCND3 (exon 6). Young patients displayed more frequent 13q31.3q32.1 amplification, 7q32q36 gain and 5q23.3 CN-LOH, while 17p13 and 18q21.3 CN-LOH were only detected in adult BLs. ID3 mutations were present in all adult samples, but only in 42% of childhood cases. CCND3 and ID3 double-hit mutations, as well as 18q21 CN-LOH, seemed to be associated with poorer outcome. For the first time, we report different genetic anomalies between adult and paediatric BLs, suggesting age-related heterogeneity in Burkitt lymphomagenesis. This may explain the poorer prognosis of adult BLs. Additional studies are needed to confirm these results in the setting of clinical trials. © 2016 John Wiley & Sons Ltd. Source

Havelange V.,Catholic University of Louvain | Ameye G.,Catholic University of Louvain | Theate I.,Catholic University of Louvain | Callet-Bauchu E.,Lyon University Hospital Center | And 19 more authors.
Genes Chromosomes and Cancer

We previously showed that complex karyotypes (CK) and chromosome 13q abnormalities have an adverse prognostic impact in childhood Burkitt lymphomas/leukemias (BL) and diffuse large B-cell lymphomas (DLBCL). The aim of our study was to identify recurrent alterations associated with MYC rearrangements in aggressive B-cell lymphomas with CK. Multicolor fluorescence in situ hybridization (M-FISH) was performed in 84 patient samples (59 adults and 25 children), including 37 BL (13 lymphomas and 24 acute leukemias), 12 DLBCL, 28 B-cell lymphomas with intermediate features (DLBCL/BL), 4 B-cell precursor acute lymphoblastic leukemias (BCP-ALL), and 3 unclassifiable B-cell lymphomas. New (cytogenetically undetected) abnormalities were identified in 80% of patients. We also refined one-third of the chromosomal aberrations detected by karyotyping. M-FISH proved to be more useful in identifying chromosomal partners involved in unbalanced translocations and in revealing greater complexity of 13q rearrangements. Most of the newly identified or refined recurrent alterations involved 1q, 13q and 3q (gains/losses), 7q and 18q (gains), or 6q (losses), suggesting that these secondary aberrations may play a role in lymphomagenesis. Several patterns of genomic aberrations were identified: 1q gains in BL, trisomies 7 in DLBCL, and 18q-translocations in adult non-BL. BCP-ALL usually displayed an 18q21 rearrangement. BL karyotypes were less complex and aneuploid than those of other MYC-rearranged lymphomas. BCP-ALL and DLBCL/BL were associated with a higher rate of early death than BL and DLBCL. These findings support the categorization of DLBCL/BL as a distinct entity and suggest that BL with CK are indeed different from other aggressive MYC-rearranged lymphomas, which usually show greater genetic complexity. © 2012 Wiley Periodicals, Inc. Source

Chapiro E.,University Paris - Sud | Chapiro E.,French Institute of Health and Medical Research | Leporrier N.,Caen University Hospital Center | Radford-Weiss I.,French Institute of Health and Medical Research | And 21 more authors.
Leukemia Research

Using array-based CGH, we identified 2p gain in 22/78 (28%) untreated Binet stages B/C CLL, which was the second most frequent copy number change after 13q deletion. It never occurred as a sole abnormality and was associated with other changes (6q deletion; 1p gain). The region of 2p gain frequently included two oncogenes, REL and MYCN. All patients with gain of REL were unmutated for IGHV (p = 0.03). Gain of MYCN was associated with increased mRNA expression (p = 0.005), suggesting a pathogenic role for MYCN. Gain of 2p appears to be a marker of progression and may contribute to the poor prognosis. © 2009 Elsevier Ltd. All rights reserved. Source

Sebaa A.,University of Paris 13 | Sebaa A.,University Djilali Liabes | Ades L.,University of Paris 13 | Baran-Marzack F.,University of Paris 13 | And 9 more authors.
Genes Chromosomes and Cancer

TP53 mutations are frequent in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) with complex karyotype that include del(5q) and are often associated with deletion of 17p. They have also recently been observed in MDS with isolated del(5q). We assessed the incidence of 17p deletion detected by fluorescence in situ hybridization (FISH) and of TP53 mutations detected by direct sequencing and their correlation and prognostic value in 26 MDS and 17 AML with del(5q). In the 20 cases with isolated del(5q) or one additional abnormality, no 17p deletion was found and 3 of the 18 cases analyzed (17%) had TP53 mutation. In the 23 patients with complex karyotype, 17p deletion was suspected by conventional cytogenetics in 15 cases and confirmed by FISH in 10 of them, while TP53 mutation was found in 8 of the 15 patients tested (53%), only five of whom had 17p deletion. In the whole patient series, TP53 mutations were associated with shorter survival (P = 0.07). We confirm the existence of TP53 mutations in 17% of MDS with isolated del(5q). In patients with del(5q) and complex karyotype, FISH and direct sequencing are complementary techniques to analyze TP53 abnormalities. Our findings also suggest that sequencing of the TP53 gene should be included in the study of patients with del(5q) as a single abnormality or in complex karyotype before lenalidomide treatment. © 2012 Wiley Periodicals, Inc. Source

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