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ABSTRACT: The cellular origin of chronic lymphocytic leukemia (CLL) is still debated, although this information is critical to understanding
its pathogenesis. Transcriptome analyses of CLL and the main normal B cell subsets from human blood and spleen revealed that
immunoglobulin variable region (IgV) gene unmutated CLL derives from unmutated mature CD5+ B cells and mutated CLL derives from a distinct, previously unrecognized CD5+CD27+ post–germinal center B cell subset. Stereotyped V gene rearrangements are enriched among CD5+ B cells, providing independent evidence for a CD5+ B cell derivation of CLL. Notably, these CD5+ B cell populations include oligoclonal expansions already found in young healthy adults, putatively representing an early
phase in CLL development before the CLL precursor lesion monoclonal B cell lymphocytosis. Finally, we identified deregulated
proteins, including EBF1 and KLF transcription factors, that were not detected in previous comparisons of CLL and conventional
B cells.
Journal of Experimental Medicine 11/2012; 209(12):2183-2198. · 13.85 Impact Factor
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Ludger Sellmann,
Alexander Carpinteiro,
Holger Nückel,
René Scholtysik,
Dörte Siemer,
Ludger Klein-Hipass,
Dieter Kube,
Jan Dürig,
Ulrich Dührsen,
Jens Stanelle,
Ralf Küppers
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ABSTRACT: Alterations in the function of the p53 pathway are frequently described in chronic lymphocytic leukemia (CLL), mostly associated with deletion of 17p13 and/or mutations of the TP53 gene. In the present study, we investigated 103 CLLs for the impact of protein expression of full-length p53 and its isoforms β and γ. A strong correlation between deletions of 17p13 and an accumulation of full-length p53 protein was found and was associated with a worse outcome compared to CLL with normal p53 (treatment-free survival p < 0.001, overall survival p = 0.04). Interestingly, the relative expression levels between full-length p53 protein and its isoforms β and γ were significantly altered in CLL even without deletions of 17p13, compared to normal B-cells (p = 0.005). Furthermore, CLLs with higher p53 protein ratios showed worse clinical courses compared to CLLs with lower p53 protein ratios. Taken together, the differential expression of p53 isoforms could disrupt the p53 response and contribute to CLL pathogenesis.
Leukemia & lymphoma 02/2012; 53(7):1282-8. · 2.40 Impact Factor
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Ludger Sellmann,
Dirk de Beer,
Marius Bartels,
Bertram Opalka,
Holger Nückel,
Ulrich Dührsen,
Jan Dürig,
Marc Seifert,
Dörte Siemer,
Ralf Küppers,
Gabriela M Baerlocher,
Alexander Röth
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ABSTRACT: In the present study, telomere length, telomerase activity, the mutation load of immunoglobulin variable heavy chain (IGHV) genes, and established prognostic factors were investigated in 78 patients with chronic lymphocytic leukaemia (CLL) to determine the impact of telomere biology on the pathogenesis of CLL. Telomere length was measured by an automated multi-colour flow-FISH, and an age-independent delta telomere length (ΔTL) was calculated. CLL with unmutated IGHV genes was associated with shorter telomeres (p = 0.002). Furthermore, we observed a linear correlation between the frequency of IGHV gene mutations and elongation of telomeres (r = 0.509, p < 0.001). With respect to prognosis, a threshold ΔTL of -4.2 kb was the best predictor for progression-free and overall survival. ΔTL was not significantly altered over time or with therapy. The correlation between the mutational load in IGHV genes and the ΔTL in CLL might reflect the initial telomere length of the putative cell of origin (pre- versus post-germinal center B cells). In conclusion, the ΔTL is a reliable prognostic marker for patients with CLL. Short telomeres and high telomerase activity as occurs in some patients with CLL with a worse prognosis might be an ideal target for treatment with telomerase inhibitors.
International journal of hematology 01/2011; 93(1):74-82. · 1.17 Impact Factor
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Ludger Sellmann,
Rene Scholtysik,
Markus Kreuz,
Sandra Cyrull,
Enrico Tiacci,
Jens Stanelle,
Alexander Carpinteiro,
Holger Nückel,
Tanja Boes,
Stefan Gesk,
Reiner Siebert,
Ludger Klein-Hitpass,
Ulrich Dührsen,
Jan Dürig,
Ralf Küppers
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ABSTRACT: To understand the influence of chromosomal alterations on gene expression in a genome-wide view, chromosomal imbalances detected by single nucleotide polymorphism (SNP) chips were compared with global gene expression in 16 cases of chronic lymphocytic leukemia (CLL). A strong concordance between chromosomal gain or loss and increased or reduced expression of genes in the affected regions was found, respectively. Regions of uniparental disomy (UPD) were rare and had usually no consistent influence on gene expression, but in one instance, a large UPD was associated with a downregulation of most genes in the affected chromosome. The frequently deleted miRNAs, MIRN15A and MIRN16-1, did not show a reduced expression in cases with monoallelic deletions. The BCL2 protein, considered to be downregulated by these miRNAs, was upregulated not only in CLL with biallelic deletion of MIRN15A and MIRN16-1, but also in cases with monoallelic deletion. This suggests a complex regulation of BCL2 levels in CLL cells. Taken together, in CLL, a global gene dosage effect exists for chromosomal gains and deletions and in some instances for UPDs. We did not confirm a consistent correlation between MIRN15A and MIRN16-1 expression levels and BCL2 protein levels, indicating a complex regulation of BCL2 expression.
Cancer genetics and cytogenetics 12/2010; 203(2):149-60. · 1.54 Impact Factor
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ABSTRACT: Fc receptor-like 2 (FCRL2) is highly expressed on B-cell chronic lymphocytic leukemia (B-CLL) cells and could possibly influence disease pathogenesis. Therefore, we investigated FCRL2 mRNA expression in a large cohort with 152 CLL patients in order to assess its role in risk prediction in B-CLL. FCRL2 mRNA expression was found to be expressed at considerably higher levels in peripheral blood mononuclear cells (PBMC) of B-CLL patients compared to controls (range 1.35- to 210-fold upregulation; P < 0.0001) and cells of other hematological diseases. Patients with high FCRL2 expression (according to ROC-analysis) had a significantly longer treatment-free survival (TFS) and overall survival (OS) than patients with low FCRL2 expression (median TFS: 119 vs. 34 months, P < 0.0001; median OS: 321 months vs. not reached, P = 0.009). Univariate comparisons found that FCRL2 expression was weakly associated with IGHV mutation status (P = 0.05), CD38 status (P < 0.0001) and ZAP-70 status (P < 0.0001). Furthermore, we show that the combination of FCRL2 with ZAP70-, CD38- or IGHV-status could further significantly refine the prognostic information provided by either of the factors alone in TFS and OS. In multivariate analysis low FCRL2 expression was a significant independent prognostic factor (HR 2.4; P = 0.005). Here we demonstrate that the level of FCRL2 expression is correlated with prognosis in B-CLL.
European Journal Of Haematology 09/2009; 83(6):541-9. · 2.61 Impact Factor
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ABSTRACT: CD49d plays a critical role in leucocyte trafficking, activation and survival, and facilitates interactions between leucocytes and stromal cells. Recent data give evidence for the prognostic relevance of CD49d protein expression in B-CLL. In our study we analyzed both the expression of CD49d protein and mRNA in a cohort of 101 CLL patients. The percentage of leukemic B-cells expressing CD49d determined by flow cytometry ranged from 0 to 100%. 37 patients with high CD49d protein expression >or=45% (according to ROC analysis) had a significantly shorter treatment-free survival (TFS) and overall survival (OS) than 64 patients with low CD49d expression (median TFS: 116 versus 43 months, p=0.015; median OS: not reached in both groups, p=0.018). CD49d protein expression was strongly associated with CD38 status (p=0.0001) and ZAP-70 status (p=0.03) but not with IGVH mutation. In multivariate analysis high CD49d expression was a significantly independent prognostic factor (HR 3.0; p=0.005). According to the strong correlation of CD49d protein expression with CD49d mRNA expression (r=0.39; p<0.0001) we could confirm the results on mRNA level with worse prognosis for patients with high mRNA level. Collectively, our data confirm the prognostic significance supporting the idea to use CD49d as target molecules for therapeutic approaches in B-CLL.
Clinical Immunology 04/2009; 131(3):472-80. · 4.05 Impact Factor
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British Journal of Haematology 12/2008; 144(2):268-70. · 4.94 Impact Factor
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ABSTRACT: Chronic lymphocytic leukemia (CLL) is characterized by a number of T-cell abnormalities, which may play a causative role in disease progression and immune dysfunction. Recently, expression levels of CD38 in T cells have been suggested as a novel adverse prognostic factor in male CLL patients. In the current study, CD38 expression on CLL T cells was examined by flow cytometry in 126 patients with B-CLL and correlated with clinical parameters and established molecular risk factors. In line with previous results we observed a positive correlation of CD38 expression on leukemic B and non-leukemic T cells with clinical stage. CD38 expression on B-CLL cells, cytogenetic aberrations and mutations of IgVH genes were found to significantly influence treatment-free survival. By contrast, CD38 expression on T cells was not significantly associated with an adverse clinical outcome.
Leukemia research 11/2008; 33(6):775-8. · 2.36 Impact Factor
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ABSTRACT: In contrast to other B-cell neoplasias, chronic lymphocytic leukaemia (CLL) is characterized by increased non-leukaemic T-cells. In order to assess their replicative history, telomere length was analyzed in subsets of leucocytes from CLL patients. Naive and memory T-cells from ZAP-70(+)/CD38(+) patients exhibited significantly shorter average telomere lengths than ZAP-70(-)/CD38(-) patients. Compared to the age-related percentiles of telomere length values from healthy individuals practically all values of the naive and memory T-cells from the ZAP-70(+)/CD38(+) CLL patients fell below the 50th percentile. This indicated an extensive expansion and a role for T-cells in ZAP-70(+)/CD38(+) CLL patients.
British Journal of Haematology 09/2008; 143(3):383-6. · 4.94 Impact Factor
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Jan Dürig,
Peter Ebeling,
Florian Grabellus,
Ursula R Sorg,
Michael Möllmann,
Philipp Schütt,
Joachim Göthert, Ludger Sellmann,
Siegfried Seeber,
Michael Flasshove,
Ulrich Dührsen,
Thomas Moritz
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ABSTRACT: We here describe a novel xenograft model of chronic lymphocytic leukemia (CLL) generated by infusion of human primary CLL cells into immunodeficient nonobese/severe combined immunodeficient (NOD/SCID) mice. Combined i.v. and i.p. injection of peripheral blood mononuclear cells (PBMC) from 39 patients with CLL resulted in highly reproducible splenic (37 of 39) and peritoneal (35 of 39) engraftment, which remained stable over a time span of 4 to 8 weeks. By comparison, recovery of leukemic cells from bone marrow (21 of 39) or peripheral blood (8 of 22) was substantially lower. The engraftment pattern of CLL PBMC 4 weeks posttransplant was correlated with clinical disease activity: infusion of PBMC from donors with Binet stage A, lymphocyte doubling time of >12 months, and normal lactate dehydrogenase (LDH) serum levels led to marked engraftment of T cells whereas comparably few tumor cells could be detected. In contrast, NOD/SCID mice receiving PBMC from donors with advanced stage Binet C, lymphocyte doubling time of <12 months, and elevated LDH serum levels exhibited predominant engraftment of tumor cells and comparably low numbers of T cells. These results suggest that this model reflects the heterogeneity and important clinical characteristics of the disease, and thus may serve as a tool for preclinical drug testing and investigation of the pathophysiology of CLL.
Cancer Research 09/2007; 67(18):8653-61. · 7.86 Impact Factor
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Ludger Sellmann,
Stefan Gesk,
Christoph Walter,
Matthias Ritgen,
Lana Harder,
José I Martín-Subero,
Roland Schroers,
Dörte Siemer,
Holger Nückel,
Martin J S Dyer,
Ulrich Dührsen,
Reiner Siebert,
Jan Dürig,
Ralf Küppers
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ABSTRACT: The occurrence of trisomy 19 was investigated in 705 cases of B-chronic lymphocytic leukaemia (CLL) by metaphase cytogenetic and/or fluorescence in situ hybridisation analyses. Trisomy 19 was detected in 11 cases (1.6%), all of which also carried a trisomy 12; nine of 10 had mutated IGHV genes. In contrast, B-CLL cases with trisomy 12 lacking trisomy 19 mostly had unmutated IGHV genes. Karyotypes of the present study and the literature identified a strong correlation to trisomy 18 in addition to trisomy 12. Trisomy 19 seems to be a secondary event in B-CLL with trisomy 12, mostly originating from mutated B cells.
British Journal of Haematology 08/2007; 138(2):217-20. · 4.94 Impact Factor
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Ludger Sellmann,
Stefan Gesk,
Christoph Walter,
Matthias Ritgen,
Lana Harder,
José I. Martín-Subero,
Roland Schroers,
Dörte Siemer,
Holger Nückel,
Martin J.S. Dyer,
Ulrich Dührsen,
Reiner Siebert,
Jan Dürig,
Ralf Küppers
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ABSTRACT: The occurrence of trisomy 19 was investigated in 705 cases of B-chronic lymphocytic leukaemia (CLL) by metaphase cytogenetic and/or fluorescence in situ hybridisation analyses. Trisomy 19 was detected in 11 cases (1·6%), all of which also carried a trisomy 12; nine of 10 had mutated IGHV genes. In contrast, B-CLL cases with trisomy 12 lacking trisomy 19 mostly had unmutated IGHV genes. Karyotypes of the present study and the literature identified a strong correlation to trisomy 18 in addition to trisomy 12. Trisomy 19 seems to be a secondary event in B-CLL with trisomy 12, mostly originating from mutated B cells.
British Journal of Haematology 06/2007; 138(2):217 - 220. · 4.94 Impact Factor
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ABSTRACT: Bcl-2 plays a key role in the regulation of apoptosis. We investigated the role of a novel regulatory single-nucleotide polymorphism (-938C>A) in the inhibitory P2 BCL2 promoter in B-cell chronic lymphocytic leukemia (B-CLL). The -938C allele displayed significantly increased BCL2 promoter activity and binding of nuclear proteins compared with the A allele. Concomitantly, Bcl-2 protein expression in B cells from CLL patients carrying the -938 AA genotype was significantly increased compared with CC genotypes. Genotype distribution between 123 CLL patients (42 AA, 55 AC, 26 CC) and 120 genotyped healthy controls (36 AA, 63 AC, 21 CC) was not significantly different, suggesting that genotypes of this polymorphism do not increase the susceptibility for B-CLL. However, median time from first diagnosis to initiation of chemotherapy and median overall survival were significantly shorter in patients with -938AA genotype (38 and 199 months, respectively) compared with AC/CC genotypes (120 and 321 months, respectively; P = .008 and P = .003, respectively). Multivariable Cox regression identified the BCL2-938AA genotype as an independent prognostic factor for the time to first treatment (hazard ratio [HR] 1.9; P = .034) together with disease stage at diagnosis (HR 2.5; P = .004) and ZAP-70 status (HR 3.0; P = .001). The BCL2-938AA genotype is associated with increased Bcl-2 expression and a novel unfavorable genetic marker in patients with B-CLL.
Blood 02/2007; 109(1):290-7. · 9.90 Impact Factor
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ABSTRACT: B-cell chronic lymphocytic leukemia (B-CLL) is characterized by the accumulation of monoclonal mature B cells. The G protein Galphas subunit has been linked to proapoptotic processes in cancer cell lines. The TT genotype of the GNAS1 T393C polymorphism is associated with increased Galphas transcript levels and a more favorable clinical course in different solid cancers.
We retrospectively genotyped 144 patients with B-CLL to examine a potential association between T393C genotypes with progression-free survival (time from diagnosis to initiation of chemotherapy) and overall survival.
The C-allele frequency in the patient group was 0.57 and not significantly different from that of healthy blood donors. Median progression-free survival was significantly different between genotypes (TT 130 months; TC 100 months; CC 31 months; P = 0.0066). Multivariable analysis showed that besides of ZAP-70 (P = 0.005) and Binet stage (P < 0.001), the T393C polymorphism was an independent prognostic factor for progression-free survival [hazard ratio (HR) CC versus TT 2.7; P = 0.010]. In Binet A stages, ZAP-70-positive patients with CC genotypes had a HR of 4.4 to receive first therapy compared with ZAP-70-negative patients with T-alleles (P = 0.0001). Regarding overall survival, CC genotypes (median overall survival, 197 months) were at highest risk for death compared with T-alleles (median overall survival, 310 months) in both univariate (HR, 4.8; P < 0.0001) and multivariable analysis (HR, 5.6; P = 0.002).
Here, we show that the GNAS1 T393C status is a novel independent prognostic marker in patients with B-CLL. These results could help to define patients who could benefit from an early individualized therapy.
Clinical Cancer Research 10/2006; 12(19):5686-92. · 7.74 Impact Factor
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ABSTRACT: B-cell chronic lymphocytic leukemia (B-CLL) is a heterogenous disease with a highly variable clinical course. Recent studies have shown that expression of lipoprotein lipase (LPL) and ADAM29 may serve as novel prognostic markers in B-CLL. To investigate the prognostic value of these genes, we quantified their expression in peripheral blood mononuclear cells using quantitative reverse transcriptase-polymerase chain reaction (RQ-PCR) in a cohort of 133 B-CLL patients and correlated the results with clinical outcome, and other known prognostic factors. LPL, ADAM29, LPL and ADAM29 ratios, as well as CD38 and ZAP-70 protein expression determined by multiparameter flow cytometry, were predictive of treatment-free survival. Multivariate Cox regression analysis identified LPL, ADAM29 and CD38 as independent prognostic markers. Evaluation of several disease characteristics in association with the LPL expression status of the patients' B-CLL cells showed highly significant differences for CD38 and ZAP-70 expression, suggesting a correlation of LPL expression with these established adverse prognostic factors. Sequential RQ-PCR analyses in a subset of 22 patients revealed that LPL mRNA expression was relatively stable in the majority of patients, whereas ADAM29 expression levels varied substantially over time. Furthermore, in a subgroup analysis, LPL provided prognostic information in both early stage (Binet A) and patients with more advanced disease (Binet B and C). Conversely, high ADAM29 expression was predictive of a long treatment-free interval in Binet stage A but did not retain its prognostic significance in Binet B and C patients. The LPL/ADAM29 expression ratio was not found to be an independent prognostic factor and did not offer any advantages over the use of LPL alone. Collectively, our data confirm a role for LPL as a novel prognostic indicator in B-CLL.
Leukemia and Lymphoma 07/2006; 47(6):1053-61. · 2.58 Impact Factor
