Project description:CD38 expression is an important prognostic marker in CLL with high levels of CD38 associated with shorter overall survival. In this study, we used gene expression profiling and protein analysis of highly purified cell-sorted CD38+ and CD38- chronic lymphocytic leukemia cells to elucidate a molecular basis for the association between CD38 expression and inferior clinical outcome. Paired CD38+ and CD38- CLL cells derived from the same patient were shown to be monoclonal by VH gene sequencing but despite this, CD38+ CLL cells possessed a distinct gene expression profile when compared with their CD38- sub-clones. Keywords: Sub-clonal analysis of CLL cells derived from the same leukemia sample
Project description:CD38 expression is an important prognostic marker in CLL with high levels of CD38 associated with shorter overall survival. In this study, we used gene expression profiling and protein analysis of highly purified cell-sorted CD38+ and CD38- chronic lymphocytic leukemia cells to elucidate a molecular basis for the association between CD38 expression and inferior clinical outcome. Paired CD38+ and CD38- CLL cells derived from the same patient were shown to be monoclonal by VH gene sequencing but despite this, CD38+ CLL cells possessed a distinct gene expression profile when compared with their CD38- sub-clones. Experiment Overall Design: These experiments compared the gene expression profile of CD38+ and CD38- sub-clones derived from 6 individual CLL patients.
Project description:The ecto-enzyme CD38 is a marker of unfavorable prognosis for chronic lymphocytic leukemia (CLL) patients and an indicator of activation and proliferation of leukemic cells. Here we show that CD38 is enzymatically active in primary CLL cells and that its forced expression increases disease aggressiveness in a xenograft model. The effect is completely lost when using an enzyme deficient version of CD38 with a single amino-acid mutation. Through the enzymatic conversion of NAD, CD38 increases cytoplasmic Ca2+ concentrations, positively influencing proliferation, chemotaxis, adhesion and matrix digestion. Inhibition of the enzymatic activities of CD38 using the flavonoid kuromanin blocks CLL homing. In a short-term xenograft model using primary cells, kuromanin treatment traps CLL cells in the blood, increasing responses to chemotherapy. Microarrays were performed comparing genetic signature derived from Mec-1 cell line variants, generated infecting cells by lentiviruses carrying the genetic material for a wild-type (CD38WT ) or an enzymatically-inactive form of CD38 (CD38M), grown in vitro and in vivo in NSG mice. GFP+ Mec-1 clones (Mec-1/GFP) were generated with the same protocol and used as control.
Project description:B-cell chronic lymphocytic leukemia (B-CLL) is a heterogenous disease with a highly variable clinical course and analysis of ZAP-70 and CD38 expression on B-CLL cells allowed for identification of patients with good (ZAP-70-CD38-), intermediate (discordant expression of ZAP-70 and CD38) and poor (ZAP-70+CD38+) prognosis. In an attempt to identify a molecular basis that may underly this diverse clinical behaviour DNA microarray technology was employed to compare eight ZAP-70+CD38+ with eight ZAP-70-CD38- B-CLL cases. We used microarrays to detail the global programme of gene expression distinguising B-CLL from patient with good (samples 1 to 8) and poor prognosis (sample 9 to 16) and identified distinct classes of up- and down-regulated genes. Experiment Overall Design: To compare the transcriptosomes of good prognosis CLL cases (ZAP-70-CD38-) to poor prognosis cases (ZAP-70+CD38+), we purified CD19+ cells from peripheral blood samples by immunomagnetic isolation using MidiMacs, resulting in >95% purity of leukemic cells as detected by FACS analysis of CD19+CD5+ cells. The leukemic cells were freshly purified from untreated patients and RNA was directly isolated from fresh cells without further ex vivo treatment of the cells. Eight immunomagnetically purified peripheral blood derived ZAP-70+CD38+ CLL cases were compared with eight ZAP-70-CD38- B-CLL cases.
Project description:With an objective to identify novel copy number alterations (CNAs) critical to CLL pathogenesis, we performed array comparative genomic hybridization (array CGH) on genomic DNA extracted from purified leukemic cells of 51 CLL patients. We used the 1.4 Mb HumArray platform, and analyzed data using a combination of three different statistical algorithms and in full awareness of the copy number variations (CNVs) found in normal populations. Use of reference DNA extracted from matched patient neutrophils in four cases also assisted a more comprehensive interpretation of constitutional versus CLL-specific copy number alterations. A total of 108 clones showed alterations in >10% of the cases. Of these, 25 clones corresponded to known recurrently acquired CNAs for CLL, representing +12 in 8 cases (16%) and del(13)(q14) in 26 cases (51%). For the remaining 83 clones, frequent deletions corresponded to loci within cytobands 17q12 (71% of CLL cases), 9q32 (55%), 8p23 (47%) and 2q21 (33%), and frequent gains corresponded to loci within cytobands 18q22.3 (51%), 20p12 (33%) and 15q13 (31%), most of which have been reported in normal population cohorts. We further analysed associations between CNV status across the 108 frequently affected clones and CD38 expression status. Consistent with previous findings, loss of 13q14 (represented in clone RPI-269F22) and gain of chromosome 12 (clones RP11-64J22, RMC12P001 and RP11-282G15) were associated with low and high CD38 expression, respectively. We also found that loss within the beta-defensin (DEFB) locus at 8p23, and gains across clones CTB-120N12 (17q25) and RP11-118K20 (13q31.1) were associated with the poor prognostic CD38+ subgroup (p<0.05). Further studies are needed to assess biological relevance of genes located within these regions and prognostic outcomes in CLL.
Project description:B-cell chronic lymphocytic leukemia (B-CLL) is a heterogenous disease with a highly variable clinical course and analysis of ZAP-70 and CD38 expression on B-CLL cells allowed for identification of patients with good (ZAP-70-CD38-), intermediate (discordant expression of ZAP-70 and CD38) and poor (ZAP-70+CD38+) prognosis. In an attempt to identify a molecular basis that may underly this diverse clinical behaviour DNA microarray technology was employed to compare eight ZAP-70+CD38+ with eight ZAP-70-CD38- B-CLL cases. We used microarrays to detail the global programme of gene expression distinguising B-CLL from patient with good (samples 1 to 8) and poor prognosis (sample 9 to 16) and identified distinct classes of up- and down-regulated genes. Keywords: Disease progression
Project description:CD38 and CD49d are associated negative prognosticators in chronic lymphocytic leukemia (CLL). Despite evidence that both molecules are involved in interactions occurring between CLL and normal cells in the context of CLL-involved tissues, a functional link is still missing. Using gene expression profiles comparing CD38+CD49d+ vs. CD38-CD49d- CLL cells, we demonstrated overexpression of the CCL3 and CCL4 chemokines in cells from the former group. These chemokines were also upregulated by CD38 signals in CLL; moreover, CCL3 was expressed by CLL cells from bone marrow biopsies (BMB) of CD38+CD49d+ but not CD38-CD49d- cases. High levels of CCR1 and, to a lesser extent, CCR5, the receptors for CCL3 and CCL4, were found in CLL-derived monocyte-macrophages. Consistently, CCL3 increased monocyte migration, and CD68+ macrophage infiltration was particularly high in BMB from CD38+CD49d+ CLL. Conditioned media from CCL3-stimulated macrophages induced endothelial cells to express VCAM-1, the CD49d ligand, likely through TNFα over-production. These effects were apparent in BMB from CD38+CD49d+CLL, where lymphoid infiltrates were characterized by a prominent meshwork of VCAM-1+ stromal/endothelial cells. Lastly, CD49d engagement by VCAM-1-transfectants increased viability of CD38+CD49d+ CLL cells. Altogether, CD38 and CD49d can be thought of as a part of a consecutive chain of events ultimately leading to improved survival of CLL cells.