Jan Dürig - Academia.edu (original) (raw)

Papers by Jan Dürig

British Journal of Haematology, 2008

The existence of functional gap junctions between haematopoietic progenitor cells (HPCs) and stro... more The existence of functional gap junctions between haematopoietic progenitor cells (HPCs) and stromal cells of the haematopoietic microenvironment in the human system is a controversial issue. Primary CD34+ HPCs isolated from leukapheresis products were co‐incubated with the human fibroblastoid bone marrow stromal cell line L87/4 in short‐term liquid culture. Using the highly sensitive double whole‐cell patch‐clamp technique, we found that the majority (91%) of CD34+ HPCs are electrically coupled to L87/4 cells. Importantly, efficient coupling was observed within 1 h of the attachment of CD34+ HPCs to plastic adherent L87/4 cells. By comparison, homologous cell pairs formed by L87/4 cells exhibited a significantly higher electric coupling. Analysis of single‐channel conductances revealed an electric profile characteristic of connexin 43 (Cx43)‐type gap junctions for both homologous and heterologous cell pairs. The Cx phenotype was confirmed using Cx43‐specific monoclonal antibodies i...

Blood cancer journal, Jan 19, 2018

T-cell prolymphocytic leukemia (T-PLL) is an aggressive malignancy with a median survival of the ... more T-cell prolymphocytic leukemia (T-PLL) is an aggressive malignancy with a median survival of the patients of less than two years. Besides characteristic chromosomal translocations, frequent mutations affect the ATM gene, JAK/STAT pathway members, and epigenetic regulators. We here performed a targeted mutation analysis for 40 genes selected from a RNA sequencing of 10 T-PLL in a collection of 28 T-PLL, and an exome analysis of five further cases. Nonsynonymous mutations were identified in 30 of the 40 genes, 18 being recurrently mutated. We identified recurrently mutated genes previously unknown to be mutated in T-PLL, which are SAMHD1, HERC1, HERC2, PRDM2, PARP10, PTPRC, and FOXP1. SAMHD1 regulates cellular deoxynucleotide levels and acts as a potential tumor suppressor in other leukemias. We observed destructive mutations in 18% of cases as well as deletions in two further cases. Taken together, we identified additional genes involved in JAK/STAT signaling (PTPRC), epigenetic regu...

Oncotarget, Jan 20, 2016

The pathogenesis of ocular adnexal marginal zone lymphomas of mucosa-associated lymphatic tissue-... more The pathogenesis of ocular adnexal marginal zone lymphomas of mucosa-associated lymphatic tissue-type (OAML) is still poorly understood. We analyzed 63 cases of such lymphomas for non-synonymous mutations in 24 candidate genes by amplicon sequencing. We validated frequent mutations in the NF-κB regulators MYD88, TNFAIP3 and TNIP1 in OAML, but also identified recurrent mutations in several additional components of the NF-κB pathway, including BCL10 and NFKBIA. Overall, 60% of cases had mutations in at least one component of NF-κB signaling, pointing to a central role of its genetic deregulation in OAML pathogenesis. Mutations in NOTCH1 and NOTCH2 were each found in 8% of cases, indicating a pathogenetic function of these factors in OAML. KMT2D was identified as the first epigenetic regulator with mutations in OAML, being mutated in 22% of cases. Mutations in MYD88 were associated with an inferior disease-free survival. Overall, we identified here highly recurrent genetic lesions in c...

Genes, Chromosomes and Cancer, 2014

T-cell prolymphocytic leukemia (T-PLL) is an aggressive post-thymic T-cell malignancy characteriz... more T-cell prolymphocytic leukemia (T-PLL) is an aggressive post-thymic T-cell malignancy characterized by the recurrent inv(14)(q11q32)/t(14;14)(q11;q32) or t(X;14)(q28;q11) leading to activation of either the TCL1 or MTCP1 gene, respectively. However, these primary genetic events are insufficient to drive leukemogenesis. Recently, activating mutations in JAK3 have been identified in other T-cell malignancies. Since JAK3 is essential for T-cell maturation, we analyzed a cohort of 32 T-PLL patients for mutational hot spots in the JAK3 gene using a step-wise screening approach. We identified 14 mutations in 11 of 32 patients (34%). The most frequently detected mutation in our cohort was M511I (seen in 57% of cases) previously described as an activating change in other T-cell malignancies. Three patients carried two mutations in JAK3. In two patients M511I and R657Q were simultaneously detected and in another patient V674F and V678L. In the latter case we could demonstrate that the mutations were on the same allele in cis. Protein modeling and homology analyses of mutations present in other members of the JAK family suggested that these mutations likely activate JAK3, possibly by disrupting the activation loop and the interface between N and C lobes, increasing the accessibility of the catalytic loop. In addition, four of the 21 patients lacking a JAK3 point mutation presented an aberrant karyotype involving the chromosomal band 19p13 harboring the JAK3 locus. The finding of recurrent activating JAK3 mutations in patients with T-PLL could enable the use of JAK3 inhibitors to treat patients with this unfavorable malignancy who otherwise have a very poor prognosis.

HemaSphere, 2018

The MabThera and Involved field Radiotherapy study investigated efficacy and safety of involved f... more The MabThera and Involved field Radiotherapy study investigated efficacy and safety of involved field (IF) radiotherapy in combination with the anti-CD20 antibody Rituximab for early-stage follicular lymphoma (FL) in a prospective, single-arm multicenter phase 2 design. Eighty-five stage I-II FL patients received 8 cycles of Rituximab (375 mg/m 2) and IF irradiation (30/40 Gy). The primary endpoint was progression-free survival (PFS) 2 years from treatment start. Secondary endpoints were overall survival (OS), complete response rates, toxicity, quality of life, and minimal residual disease (MRD) response with protocol defined visits up to month 30. For the primary endpoint, PFS at 2 years was 85% for the intention-to-treat set. Long-term data were captured in selected sites and evaluated as post hoc analysis in the per protocol (PP) set: PFS and OS were 78% and 96% at 5 years with a median follow-up of 66 or 78 months, respectively. There were 17/76 recurrences in the PP set, of which 14 were outside the radiation volume only. MRD analyses revealed a clonal marker in 36% of patients at diagnosis. All but 1 marker positive patients experienced a molecular treatment response. There were 13 serious adverse events (4 related to the therapy) during the first 30 months. IF radiotherapy combined with Rituximab is well tolerated and highly efficient with low rates of recurrence in the first years in early-stage FL. The efficacy is comparable with more aggressive therapy approaches without compromising the quality of life and maintains for an extended follow-up of more than 5 years.

Bcl-2 plays a key role in the regulation of apoptosis. We investigated the role of a novel regula... more Bcl-2 plays a key role in the regulation of apoptosis. We investigated the role of a novel regulatory single-nucleotide polymorphism (938C&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;A) in the inhibi- tory P2 BCL2 promoter in B-cell chronic lymphocytic leukemia (B-CLL). The 938C allele displayed significantly in- creased BCL2 promoter activity and binding of nuclear proteins compared with the A allele. Concomitantly, Bcl-2 protein expression in B

International journal of cancer. Journal international du cancer, Jan 21, 2015

The pathogenesis of T-cell large granular lymphocytic leukemia (T-LGL) is poorly understood, as S... more The pathogenesis of T-cell large granular lymphocytic leukemia (T-LGL) is poorly understood, as STAT3 mutations are the only known frequent genetic lesions. Here, we identified non-synonymous alterations in the TNFAIP3 tumor suppressor gene in 3 of 39 T-LGL. In two cases these were somatic mutations, in one case the somatic origin was likely. A further case harbored a SNP that is a known risk allele for autoimmune diseases and B cell lymphomas. Thus, TNFAIP3 mutations represent recurrent genetic lesions in T-LGL that affect about 8% of cases, likely contributing to deregulated NF-κB activity in this leukemia.

Leukemia, 2001

Chemokines are a family of 8-10 kDa proteins with a wide range of biological activities including... more Chemokines are a family of 8-10 kDa proteins with a wide range of biological activities including the regulation of leukocyte trafficking, modulation of haemopoietic cell proliferation and adhesion to extracellular matrix molecules. Using a panel of chemokine receptor-specific monoclonal antibodies (MoAb) in a multicolour flow cytometry approach we analysed the expression of the lymphocyte-associated chemokine receptors CXCR4, CXCR5, CCR5 and CCR6 in B cell acute lymphoblastic leukaemia (precursor B-ALL; six cases), B cell chronic lymphocytic leukaemia (B-CLL; 31 cases), multiple myeloma (10 cases), mantle cell lymphoma (MCL, four cases), follicular lymphoma (FL, three cases) and hairy cell leukaemia (HCL, five cases). We demonstrate that CXCR4, CXCR5 and CCR6 are differentially expressed in these B lymphoproliferative disorders depending on the maturational stage of the malignant B cell population investigated. In particular, we found that CXCR4 is strongly expressed on immature AL...

Leukemia, 2000

We compared the biological effects of the CXC chemokine SDF-1α on immunomagnetically purified CD3... more We compared the biological effects of the CXC chemokine SDF-1α on immunomagnetically purified CD34+ cells isolated from human normal bone marrow (NBM), leukapheresis products (LP) and patients with chronic myeloid leukaemia (CML). LP CD34+ cells showed a significantly stronger migration response to SDF-1α (100 ng/ml) than CD34+ cells isolated from the peripheral blood (PB) of CML patients (P 0.05). Finally,

Leukemia Research, 2009

Chronic lymphocytic leukemia (CLL) is characterized by a number of T-cell abnormalities, which ma... more 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, 2008

Microarray-based gene expression profiling (GEP) was used to study how stroma modulates the survi... more Microarray-based gene expression profiling (GEP) was used to study how stroma modulates the survival of CLL cells in an in vitro coculture model employing the murine fibroblast cell line M2-10B4. CLL cells cultured in direct contact with the stromal layer (STR) showed a significantly better survival than cells cultured in transwell (TW) inserts above the M2-10B4 cells. STR as compared to TW conditions induced a significant up-regulation of PI3K/NF-kappaB pro-survival pathway genes and mediated a pro-angiogenetic switch in the CLL cells by up-regulation of vascular endothelial growth factor (VEGF) and osteopontin (OPN) and down-regulation of the anti-angiogenetic molecule thrombospondin-1 (TSP-1).

Leukemia Research, 2010

Recently developed molecular prognostic tests in patients with early Binet stage chronic lymphocy... more Recently developed molecular prognostic tests in patients with early Binet stage chronic lymphocytic leukemia (B-CLL) are costly and often require a high level of technologic expertise. Recent data give evidence for the prognostic relevance of the percentage of smudge cells in B-CLL. In our study we analysed the prognostic potential of this novel marker in a cohort of 100 CLL patients. The percentage of smudge cells ranged from 0% to 70% (median 21%). Patients with ≤20% smudge cells (according to ROC analysis) had a significantly shorter time to first treatment and overall survival than patients with >20% smudge cells. Multivariate Cox regression analysis identified percentages of smudge cells, stage according to Binet and CD38 expression as independent prognostic markers. The percentage of smudge cells was significantly lower in CD38+, ZAP-70+ and unmutated IgVH patients. Combined analysis of smudge cell percentages with CD38 expression provided complementary prognostic information identifying three patient subgroups with good, intermediate and poor prognosis. Comparing gene expression profiles in a subset of 12 patients we identified eight differentially expressed genes in groups with high vs. low percentage of smudge cells suggesting a role of these differentially expressed genes, especially for Tribbles homolog 2 (Trib2), in the disease progression of high risk CLL patients.

Leukemia, 2006

B-cell chronic lymphocytic leukaemia (B-CLL) is a heterogenous disease with a highly variable cli... more B-cell chronic lymphocytic leukaemia (B-CLL) is a heterogenous disease with a highly variable clinical course and analysis of zeta-associated protein 70 (ZAP-70) and CD38 expression on B-CLL cells allowed for identification of patients with good (ZAP-70 À CD38 À ) and poor (ZAP-70 þ CD38 þ ) prognosis. DNA microarray technology was employed to compare eight ZAP-70 þ CD38 þ with eight ZAP-70 À CD38 À B-CLL cases. The expression of 358 genes differed significantly between the two subgroups, including genes involved in B-cell receptor signaling, angiogenesis and lymphomagenesis. Three of these genes, that is, immune receptor translocation-associated protein 4 (IRTA4)/Fc receptor homologue 2 (FcRH2), angiopoietin 2 (ANGPT2) and Pim2 were selected for further validating studies in a cohort of 94 B-CLL patients. IRTA4/FcRH2 expression as detected by flow cytometry was significantly lower in the poor prognosis subgroup as compared to ZAP-70 À CD38 À B-CLL cells. In healthy individuals, IRTA4/FcRH2 protein expression was associated with a CD19 þ CD27 þ memory cell phenotype. ANGPT2 plasma concentrations were twofold higher in the poor prognosis subgroup (Po0.05). Pim2 was significantly overexpressed in poor prognosis cases and Binet stage C. Disease progression may be related to proangiogenic processes and strong Pim2 expression.

Leukemia, 2005

Prognostic predictions in B-cell chronic lymphocytic leukemia (B-CLL) at early clinical stage are... more Prognostic predictions in B-cell chronic lymphocytic leukemia (B-CLL) at early clinical stage are based on biological disease parameters, such as ZAP-70 and CD38 protein levels, genomic aberrations as well as immunoglobulin variable heavy chain gene (IgV H ) mutation status. In the current study, ZAP-70 and CD38 expressions were examined by flow cytometry in 252 patients with B-CLL. Cytoplasmic ZAP-70 expression in more than 20% (ZAP-70 þ ) and surface CD38 expression on more than 30% (CD38 þ ) of B-CLL cells were associated with an unfavorable clinical course. The levels of ZAP-70 and CD38 did not change over time in the majority of patients where sequential samples were available for analysis. Combined analysis of ZAP-70 and CD38 yielded discordant results in 73 patients (29.0%), whereas 120 patients (47.6%) were concordantly negative and 59 patients (23.4%) were concordantly positive for ZAP-70 and CD38 expression. Median treatment-free survival times in patients whose leukemic cells were ZAP-70 þ CD38 þ was 30 months as compared to 130 months in patients with a ZAP-70 À CD38 À status. In patients with discordant ZAP-70/CD38 results, the median treatment-free survival time was 43 months. Thus, ZAP-70 and CD38 expression analyses provided complementary prognostic information identifying three patient subgroups with good, intermediate and poor prognosis. Over-representation of high-risk genomic aberrations such as 17p deletion or 11q deletion and distribution of the IgV H mutation status in B-CLL discordant for ZAP-70/ CD38 pointed toward a distinct biologic background of the observed disease subgroups. This finding was also supported by microarray-based gene expression profiling in a subset of 35 patients. The expression of 37 genes differed significantly between the three groups defined by their expression of ZAP-70 and CD38, including genes that are involved in regulation of cell survival and chemotherapy resistance.

Leukemia, 2003

B-cell chronic lymphocytic leukemia (B-CLL) is a heterogenous disease with a highly variable clin... more B-cell chronic lymphocytic leukemia (B-CLL) is a heterogenous disease with a highly variable clinical course. Recent studies have shown that expression of the protein tyrosine kinase ZAP-70 may serve as a prognostic marker in B-CLL. Employing a semiquantitative RT-PCR assay, we examined purified leukemia B cells of 39 CLL patients for the expression of ZAP-70 mRNA transcripts. Significant ZAP-70 mRNA levels exceeding those found in control samples with 5% T cells were detected in 36% of the CLL cases. Patients in the ZAP-70 positive cohort were characterized by an unfavorable clinical course with a significantly shorter progression-free survival as compared to the ZAP-70-negative patients (64%). These results were confirmed by flow-cytometric analysis of the ZAP-70 protein, and expanded to a larger patient cohort (n=67). A combined statistical analysis of 79 patients showed that the two patient subgroups also differed with regard to overall survival and a panel of known clinical prognostic factors including LDH, thymidine kinase serum levels and expression of the CD38 surface antigen by the leukemic cell clone. The level of ZAP-70 expression did not change over time in the majority of patients where sequential samples were available for analysis.

Leukemia, 2011

SPC2996 is a novel locked nucleic acid phosphorothioate antisense molecule targeting the mRNA of ... more SPC2996 is a novel locked nucleic acid phosphorothioate antisense molecule targeting the mRNA of the Bcl-2 oncoprotein. We investigated the mechanism of action of SPC2996 and the basis for its clinically observed immunostimulatory effects in chronic lymphocytic leukemia (CLL). Patients with relapsed CLL were treated with a maximum of six doses of SPC2996 (0.2-6 mg/kg) in a multicenter phase I trial. Microarray-based transcriptional profiling of circulating CLL cells was carried out before and after the first infusion of SPC2996 in 18 patients. Statistically significant transcriptomic changes were observed at doses 4 mg/kg and occurred as early as 24 h after the first infusion of the oligonucleotide. SPC2996 induced the upregulation of 466 genes including a large number of immune response and apoptotic regulator molecules, which were enriched for Toll-like receptor response genes. Serum measurements confirmed the release of pro-inflammatory cytokines including chemokine (C-C motif) ligand 3 (macrophage inflammatory protein 1α) and tumor necrosis factor-α, thereby validating the in vivo transcriptomic data at the protein level. SPC2996 caused a 50% reduction of circulating lymphocytes in five of 18 (28%) patients, which was found to be independent of its immunostimulatory and anti-Bcl-2 effects.

Leukemia, 2002

Employing a multicolour flow cytometry assay, 133 B-chronic lymphocytic leukaemia (B-CLL) cases w... more Employing a multicolour flow cytometry assay, 133 B-chronic lymphocytic leukaemia (B-CLL) cases were analysed for surface expression of CD38. Based on a cut-off value of 20%, CLL patients were categorised into a CD38-positive (> or = 20%, n = 56) and a CD38-negative subgroup (< 20%, n = 77) and separately analysed for clinical and laboratory parameters. Patients in the CD38-positive cohort were characterised by an unfavourable clinical course with a more advanced disease stage, poor responsiveness to chemotherapy, short time to initiation of first treatment and shorter survival. In contrast, the CD38- negative group required minimal or no treatment, remained treatment-free for a longer time period and had prolonged survival (P < 0.05). CD38 expression was a robust marker in the majority of patients in that it was stable over time and not significantly influenced by chemotherapy. In conclusion, our data confirm recent studies suggesting a role of CD38 as a predictor of clinical outcome in patients with B-CLL.

Leukemia, 2007

To test the role of telomere biology in T-cell prolymphocytic leukemia (T-PLL), a rare aggressive... more To test the role of telomere biology in T-cell prolymphocytic leukemia (T-PLL), a rare aggressive disease characterized by the expansion of a T-cell clone derived from immuno-competent post-thymic T-lymphocytes, we analyzed telomere length and telomerase activity in subsets of peripheral blood leukocytes from 11 newly diagnosed or relapsed patients with sporadic T-PLL. Telomere length values of the leukemic T cells (mean+/-s.d.: 1.53+/-0.65 kb) were all below the 1st percentile of telomere length values observed in T cells from healthy age-matched controls whereas telomere length of normal T- and B cells fell between the 1st and 99th percentile of the normal distribution. Leukemic T cells exhibited high levels of telomerase and were sensitive to the telomerase inhibitor BIBR1532 at doses that showed no effect on normal, unstimulated T cells. Targeting the short telomeres and telomerase activity in T-PLL seems an attractive strategy for the future treatment of this devastating disease.