Identification of a gene on chromosome 12q22 uniquely overexpressed in chronic lymphocytic leukemia

Blood ◽  
2006 ◽  
Vol 107 (7) ◽  
pp. 2904-2911 ◽  
Author(s):  
Anne Mette Buhl ◽  
Jesper Jurlander ◽  
Flemming S. Jørgensen ◽  
Anne Marie Ottesen ◽  
Jack B. Cowland ◽  
...  

Abstract The pathogenesis of chronic lymphocytic leukemia (CLL) is unknown but may involve aberrant activation of signaling pathways. Somatic hypermutations in rearranged immunoglobulin heavy-chain (IgVH) genes allow a division of CLL patients into 2 categories: mutated IgVH genes are associated with an indolent disease, whereas unmutated IgVH genes define an aggressive form. Using differential display to compare gene expression in CLL cells with and without IgVH hypermutations, we identified a novel gene, CLL up-regulated gene 1 (CLLU1), that was highly up-regulated in CLL cells without IgVH hypermutations. CLLU1 mapped to chromosome 12q22, within a cluster of genes that are active in germinal center B cells. However, appreciable levels of CLLU1 were detectable only in CLL cells and not in a panel of normal tissue extracts or in any other tested hematologic malignancy. High expression of CLLU1 in CLL samples occurred irrespective of trisomy 12 or large chromosomal rearrangements. CLLU1 encodes 6 mRNAs with no sequence homology to any known gene, and most transcripts appear to be noncoding. Two transcripts, however, potentially encode a peptide with remarkable structural similarity to human interleukin 4. These data, in particular the unique and restricted expression pattern, suggest that CLLU1 is the first disease-specific gene identified in CLL.

2018 ◽  
Vol 40 (4) ◽  
pp. 261-267 ◽  
Author(s):  
K Tari ◽  
Z Shamsi ◽  
H Reza Ghafari ◽  
A Atashi ◽  
M Shahjahani ◽  
...  

Chronic lymphocytic leukemia (CLL) is increased proliferation of B-cells with peripheral blood and bone marrow involvement, which is usually observed in older people. Genetic mutations, epigenetic changes and miRs play a role in CLL pathogenesis. Del 11q, del l17q, del 6q, trisomy 12, p53 and IgVH mutations are the most important genetic changes in CLL. Deletion of miR-15a and miR-16a can increase bcl2 gene expression, miR-29 and miR-181 deletions decrease the expression of TCL1, and miR-146a deletion prevents tumor metastasis. Epigenetic changes such as hypo- and hypermethylation, ubiquitination, hypo- and hyperacetylation of gene promoters involved in CLL pathogenesis can also play a role in CLL. Expression of CD38 and ZAP70, presence or absence of mutation in IgVH and P53 mutation are among the factors involved in CLL prognosis. Use of monoclonal antibodies against surface markers of B-cells like anti-CD20 as well as tyrosine kinase inhibitors are the most important therapeutic approaches for CLL.


2014 ◽  
Vol 53 (8) ◽  
pp. 657-666 ◽  
Author(s):  
Adrien Cosson ◽  
Elise Chapiro ◽  
Nabila Belhouachi ◽  
Hong-Anh Cung ◽  
Boris Keren ◽  
...  

Blood ◽  
2002 ◽  
Vol 100 (5) ◽  
pp. 1787-1794 ◽  
Author(s):  
Urban Novak ◽  
Elisabeth Oppliger Leibundgut ◽  
Jörg Hager ◽  
Dominique Mühlematter ◽  
Martine Jotterand ◽  
...  

The most frequent chromosomal aberrations in B-cell chronic lymphocytic leukemia (B-CLL) are deletions on 13q, 11q, and 17p, and trisomy 12, all of which are of prognostic significance. Conventional cytogenetic analysis and fluorescence in situ hybridization (FISH) are used for their detection, but cytogenetic analysis is hampered by the low mitotic index of B-CLL cells, and FISH depends on accurate information about candidate regions. We used a set of 400 highly informative microsatellite markers covering all chromosomal arms (allelotyping) and automated polymerase chain reaction (PCR) protocols to screen 46 patients with typical B-CLL for chromosomal aberrations. For validation, we compared data with our conventional karyotype results and fine mapping with conventional single-site PCR. All clonal cytogenetic abnormalities potentially detectable by our microsatellite PCR (eg, del13q14 and trisomy 12) were picked up. Allelotyping revealed additional complex aberrations in patients with both normal and abnormal B-CLL karyotypes. Aberrations detectable in the samples with our microsatellite panel were found on almost all chromosomal arms. We detected new aberrant loci in typical B-CLL, such as allelic losses on 1q, 9q, and 22q in up to 25% of our patients, and allelic imbalances mirroring chromosomal duplications, amplifications, or aneuploidies on 2q, 10p, and 22q in up to 27% of our patients. We conclude that allelotyping with our battery of informative microsatellites is suitable for molecular screening of B-CLL. The technique is well suited for analyses in clinical trials, it provides a comprehensive view of genetic alterations, and it may identify new loci with candidate genes relevant in the molecular biology of B-CLL.


2017 ◽  
Vol 39 (2) ◽  
pp. 141-144
Author(s):  
S V Andreieva ◽  
K V Korets ◽  
O E Ruzhinska ◽  
I M Skorokhod ◽  
O G Alkhimova

Aim: The genetic mechanisms of resistance to chemotherapy in B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma (B-CLL/SLL) are not clear. We aimed to determine the peculiarities of abnormal karyotype formation in bone marrow (BM) cells and peripheral blood (PB) blast transformed B-cells in relapse of B-CLL/SLL. Materials and Methods: Cytogenetic GTG banding technique and molecular cytogenetic in interphase cells (i-FISH) studies of BM cells and PB blast transformed B-lymphocytes were performed in 14 patients (10 males and 4 females) with B-CLL/SLL. Results: The results of karyotyping BM and PB cells revealed the heterogeneity of cytogenetic abnormalities in combined single nosological group of B-CLL/SLL. In PB B-cells, chromosome abnormalities related to a poor prognosis group were registered 2.5 times more often than in BM cells. Additional near tetraploid clones that occurred in 57.1% cases were the peculiar feature of BM cell karyotypes. Chromosomal rearrangements characteristic of the group of adverse cytogenetic prognosis were revealed in all cases from which in 2 cases by karyotyping BM cells, in 6 cases in PB B-cells and in 8 cases by the i-FISH method in BM cells, i.e. their detection frequency was 3 times higher in PB B-cells and 4 times higher when analyzing by i-FISH in BM cells. Conclusions: Mismatch in abnormal karyotypes in BM and PB B-cells by the presence of quantitative and structural chromosomal rearrangements may be indicative of simultaneous and independent processes of abnormal clone formation in the lymph nodes and BM hematopoietic cells. Accumulation the information about previously unidentified chromosomal rearrangements in relapse of the disease may help to understand the ways of resistance formation to chemotherapy.


2000 ◽  
Vol 23 (3) ◽  
pp. 531-533 ◽  
Author(s):  
Maria de Lourdes L.F. Chauffaille ◽  
Eliana Azevedo Marques ◽  
Jose Salvador Rodrigues de Oliveira ◽  
Maria Madalena Rodrigues ◽  
Maria Stella Figueiredo ◽  
...  

Chronic lymphocytic leukemia (CLL) presents a varying incidence of karyotypic abnormalities whose detection is complicated by difficulties in obtaining mitosis for analysis in this type of mature lymphocyte disorder. Since the introduction of molecular cytogenetics (FISH = fluorescent in situ hybridization), applying centromeric probes for chromosome 12 has made it possible to detect a higher percentage of trisomy 12 cases. The objective of the present study was to detect trisomy 12 by FISH (alpha satellite probe) in 13 patients with CLL whose karyotypes by G-banding were either normal or inadequate. Using this method trisomy 12 was detected in three patients in a percentage of positive cells varying from 55.5% to 79%, showing that FISH is a sensitive and highly specific method for trisomy detection and should be routinely performed when the karyotype is normal.


2003 ◽  
Vol 127 (5) ◽  
pp. 561-566 ◽  
Author(s):  
Ellen Schlette ◽  
L. Jeffrey Medeiros ◽  
Michael Keating ◽  
Raymond Lai

Abstract Context.—CD79b is a relatively newly characterized B-cell marker that is expressed in a minority of chronic lymphocytic leukemia (CLL) cases. Objective.—To systematically correlate CD79b expression with specific morphologic and immunophenotypic findings and trisomy 12. Design.—We assessed CD79b expression in 100 consecutively accrued CLL cases that were also analyzed by conventional cytogenetics. Based on the association between trisomy 12 and CD79b expression, we then assessed 43 additional CLL cases with trisomy 12. CD79b expression was correlated with morphology and expression of other immunophenotypic markers. Results.—Eighteen (18%) of 100 consecutively accrued cases were CD79b positive. No significant association was found between CD79b expression and atypical morphology. CD79b expression correlated with CD22 and FMC7 positivity. Eight (8%) cases had trisomy 12; 4 (50%) of these were CD79b positive, suggesting an association with trisomy 12. Examination of a second group of 51 CLL cases with trisomy 12 (including 8 cases from the initial study group) showed that CD79b was positive in 26 cases (49%), a frequency significantly higher than that of the consecutively accrued CLL cases without trisomy 12 (P < .05). Conclusions.—We conclude that CD79b immunoreactivity is positive in approximately 20% of CLL cases and that expression correlates with trisomy 12 and atypical immunophenotypic findings.


2020 ◽  
Author(s):  
Malihe Bagheri ◽  
Behzad Khansarinejad ◽  
Ghasem Mosayebi ◽  
Alireza Moradabadi ◽  
Mahdieh Mondanizadeh

Abstract Background: Chronic lymphocytic leukemia (CLL) is one of the most common hematologic malignancy in adults worldwide. This cancer has a poor prognosis at different stages. So, the identification of new biomarkers is important for early diagnosis of B-CLL. Considering the oncogenic role of APRIL molecule in this leukemia as well as the regulatory role of microRNAs (miRNAs) in different signaling pathways, the present study evaluated the miRNAs targeting APRIL gene in B-CLL.Methods: The miRNAs were predicted and selected using bioinformatics algorithms. A total of 80 plasma samples (40 samples of healthy individuals and 40 samples of B-CLL patients) were subjected to RNA extraction and synthesis of cDNA. The expressions levels of predicted miRNAs and APRIL gene in plasma of B-CLL patients and healthy individuals were assessed by Real time PCR analysis. ROC analysis was performed to investigate the role predicted miRNAs as novel biomarkers in diagnosis of B-CLL. Results: The results of the prediction showed that miR-145-5p and miR-185-5p target the APRIL gene. The expression level of APRIL gene was strikingly higher in plasma of B-CLL patients than in the healthy individuals (102, P= 0.001). On the other hand, expression levels of miR-145-5p and miR-185-5p were strikingly lower in B-CLL patients than in the healthy individuals (0.07, P= 0.001) (0.29, P= 0.001). Also, ROC curve analyses demonstrated that miR-145-5p and miR-185-5p are specific and sensitive and may serve as new biomarkers for the early detection of B-CLL. Conclusions: These data suggest that the study miRNAs may have a role in B-CLL development and progression. Moreover, miR-145-5p and miR-185-5p can be served as a novel and potential biomarker in the diagnosis of B-CLL.


Hematology ◽  
2017 ◽  
Vol 2017 (1) ◽  
pp. 329-337 ◽  
Author(s):  
Gianluca Gaidano ◽  
Davide Rossi

Abstract The typical genome of chronic lymphocytic leukemia (CLL) carries ∼2000 molecular lesions. Few mutations recur across patients at a frequency >5%, whereas a large number of biologically and clinically uncharacterized genes are mutated at lower frequency. Approximately 80% of CLL patients carry at least 1 of 4 common chromosomal alterations, namely deletion 13q14, deletion 11q22-23, deletion 17p12, and trisomy 12. Knowledge of the CLL genome has translated into the availability of molecular biomarkers for prognosis and treatment prediction. Prognostic biomarkers do not affect treatment choice, and can be integrated into prognostic scores that are based on both clinical and biological variables. Molecular predictive biomarkers affect treatment choice, and currently include TP53 disruption by mutation and/or deletion and IGHV mutation status. TP53 disruption by gene mutation and/or deletion associates with chemoimmunotherapy failure and mandates treatment with innovative drugs, including ibrutinib, idelalisib, or venetoclax. The mutation status of IGHV genes represents a predictive biomarker for identifying patients that may benefit the most from chemoimmunotherapy with fludarabine, cyclophosphamide, and rituximab. Assessment of these biomarkers at the time of treatment requirement is recommended by most current guidelines for CLL management. Other molecular predictors are under investigation, but their application in clinical practice is premature.


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