The ectopic expression of olfactory receptors (ORs) in the human body has been of major interest in the past decade. Several studies have reported the expression of ORs not only in healthy tissues ...such as heart, sperm or skin cells, but also in cancerous tissues of the liver, prostate or intestine. In the present study, we detected the expression of OR51B5 in the chronic myelogenous leukemia (CML) cell line K562 and in white blood cell samples of clinically diagnosed acute myelogenous leukemia (AML) patients by reverse transcription-PCR and immunocytochemical staining. The known OR51B5 ligand isononyl alcohol increased the levels of intracellular Ca(2+) in both AML patient blood cells and K562 cells. With calcium imaging experiments, we characterized in greater detail the OR51B5-mediated signaling pathway. Here, we observed an involvement of adenylate cyclase and the downstream L-type and T-type calcium channels. In addition, the activation of OR51B5 leads to an inhibition of cell proliferation in K562 cells. In western blot experiments, we found that incubation with isononyl alcohol led to a reduction in p38-MAPK (mitogen-activated protein kinase) phosphorylation that might be responsible for the decreased cell proliferation. In the present study, we characterized the OR51B5-mediated signaling pathway downstream of the activation with isononyl alcohol, which leads to reduced proliferation and therefore provide a novel pharmacological target for CML and AML, the latter of which remains difficult to treat.
In the CORAL study, 255 chemosensitive relapses with diffuse large B-cell lymphoma (DLBCL) were consolidated with autologous stem cell transplantation (ASCT), and 75 of them relapsed thereafter. The ...median time between ASCT and progression was 7.1 months. The median age was 56.1 years; tertiary International Prognosis Index (tIPI) observed at relapse was 0-2 in 71.6% of the patients and >2 in 28.4%. The overall response rate to third-line chemotherapy was 44%. The median overall survival (OS) was 10.0 months (median follow-up: 32.8 months). Thirteen patients received an allogeneic SCT, and three a second ASCT. The median OS was shorter among patients who relapsed <6 months (5.7 months) compared with those relapsing ⩾12 months after ASCT (12.6 months, P=0.0221). The median OS in patients achieving CR, PR or no response after the third-line regimen was 37.7 (P<0.0001), 10.0 (P=0.03) and 6.3 months, respectively. The median OS varied according to tIPI: 0-2: 12.6 months and >2: 5.3 months (P=0.0007). In multivariate analysis, tIPI >2, achievement of response and remission lasting <6 months predicted the OS. This report identifies the prognostic factors for DLBCL relapsing after ASCT and thus helps to select patients for experimental therapy.
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.
Lysine (K)-specific demethylase 1A (LSD1/KDM1A) has been identified as a potential therapeutic target in solid cancers and more recently in acute myeloid leukemia. However, the potential side effects ...of a LSD1-inhibitory therapy remain elusive. Here, we show, with a newly established conditional in vivo knockdown model, that LSD1 represents a central regulator of hematopoietic stem and progenitor cells. LSD1 knockdown (LSD1-kd) expanded progenitor numbers by enhancing their proliferative behavior. LSD1-kd led to an extensive expansion of granulomonocytic, erythroid and megakaryocytic progenitors. In contrast, terminal granulopoiesis, erythropoiesis and platelet production were severely inhibited. The only exception was monopoiesis, which was promoted by LSD1 deficiency. Importantly, we showed that peripheral blood granulocytopenia, monocytosis, anemia and thrombocytopenia were reversible after LSD1-kd termination. Extramedullary splenic hematopoiesis contributed to the phenotypic reversion, and progenitor populations remained expanded. LSD1-kd was associated with the upregulation of key hematopoietic genes, including Gfi1b, Hoxa9 and Meis1, which are known regulators of the HSC/progenitor compartment. We also demonstrated that LSD1-kd abrogated Gfi1b-negative autoregulation by crossing LSD1-kd with Gfi1b:GFP mice. Taken together, our findings distinguish LSD1 as a critical regulator of hematopoiesis and point to severe, but reversible, side effects of a LSD1-targeted therapy.
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.
T-cell prolymphocytic leukemia (T-PLL) is a rare aggressive lymphoma derived from mature T cells, which is, in most cases, characterized by the presence of an inv(14)(q11q32)/t(14;14)(q11;q32) and a ...characteristic pattern of secondary chromosomal aberrations. DNA microarray technology was employed to compare the transcriptomes of eight immunomagnetically purified CD3+ normal donor-derived peripheral blood cell samples, with five highly purified inv(14)/t(14;14)-positive T-PLL blood samples. Between the two experimental groups, 734 genes were identified as differentially expressed, including functionally important genes involved in lymphomagenesis, cell cycle regulation, apoptosis and DNA repair. Notably, the differentially expressed genes were found to be significantly enriched in genomic regions affected by recurrent chromosomal imbalances. Upregulated genes clustered on chromosome arms 6p and 8q, and downregulated genes on 6q, 8p, 10p, 11q and 18p. High-resolution copy-number determination using single nucleotide polymorphism chip technology in 12 inv(14)/t(14;14)-positive T-PLL including those analyzed for gene expression, refined chromosomal breakpoints as well as regions of imbalances. In conclusion, combined transcriptional and molecular cytogenetic profiling identified novel specific chromosomal loci and genes that are likely to be involved in disease progression and suggests a gene dosage effect as a pathogenic mechanism in T-PLL.
Guideline recommendations for diffuse large-B-cell lymphoma (DLBCL) treatment are shifting from long to short treatment duration, although it is still unclear whether shortening treatment duration ...does not cause any harm. As interim PET (I-PET) has high negative predictive value for progression, we evaluated the cost-effectiveness of shortening treatment duration dependent on I-PET result.
We developed a Markov cohort model using the PET Re-Analysis (PETRA) database to evaluate a long treatment duration (LTD) strategy, ie 8x R-CHOP or 6x R-CHOP plus 2 R, and a short treatment duration (STD) strategy, ie 6x R-CHOP. Strategies were evaluated separately in I-PET2 positive and I-PET2 negative patients. Outcomes included total costs and quality-adjusted life-years (QALYs) per patient (pp) from a societal perspective. Net monetary benefit (NMB) per strategy was calculated using a willingness-to-pay threshold of €50,000/QALY. Robustness of model predictions was assessed in sensitivity analyses.
In I-PET2 positive patients, shortening treatment duration led to 50.4 additional deaths per 1000 patients. The STD strategy was less effective (-0.161 95%CI: -0.343;0.028 QALYs pp) and less costly (-€2768 95%CI: -€8420;€1105 pp). Shortening treatment duration was not cost-effective (incremental NMB -€5281). In I-PET2 negative patients, shortening treatment duration led to 5.0 additional deaths per 1000 patients and a minor difference in effectiveness (-0.007 95%CI: -0.136;0.140 QALY pp). The STD strategy was less costly (-€5807 95%CI: -€10,724;-€2685 pp) and led to an incremental NMB of €5449, indicating that it is cost-effective to shorten treatment duration. Robustness of these findings was underpinned by deterministic and probabilistic sensitivity analyses.
Treatment duration should not be shortened in I-PET2 positive patients whereas it is cost-effective to shorten treatment duration in I-PET2 negative patients.
Guideline recommendations for diffuse large-B-cell lymphoma treatment are shifting from long to short treatment duration. Using a Markov model, we evaluated the cost-effectiveness of this shortening in treatment duration, separately in I-PET positive and I-PET negative patients. We showed that this shift is justified for I-PET negative patients, but not for I-PET positive patients as shortening treatment duration in these patients has harmful consequences.
Chemotherapy for elderly patients with acute myeloid leukemia (AML) results in a median overall survival (OS) of ≤1 year. Elderly patients often present with cardiac comorbidity. Gemtuzumab ...ozogamicin (GO) is active in elderly (≥60 years) patients with relapsed AML with low cardiac toxicity.
This randomized phase II study compared a standard combination of ara-C and daunorubicin (DNR; 7+3) versus ara-C plus gemtuzumab ozogamicin (7+GO) as the first course of induction therapy. Primary objectives were comparison of blast clearance on day 16, event-free survival (EFS), and remission duration. OS, complete remission (CR), and tolerability were secondary objectives.
One hundred and nineteen patients with de novo AML, treatment-related AML, AML with a history of myelodysplastic syndrome (MDS), or high-risk MDS entered the study. Median age of 115 patients (intent-to-treat population) was 69 years. Protocol outlined a second course 7+3 for patients without blast clearance and two courses of high-dose ara-C consolidation upon CR. Both treatments were equally effective in blast clearance, CR, EFS, remission duration, or OS (median: 7+3, 9 months; 7+GO, 10 months). Induction death rate was higher in the GO group due to veno-occlusive disease.
The study did not show significant superiority of 7+GO over standard 7+3.
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-CD38-) and poor (ZAP-70+CD38+) prognosis. DNA microarray technology was employed to compare eight ZAP-70+CD38+ with eight ZAP-70-CD38- 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-CD38- B-CLL cells. In healthy individuals, IRTA4/FcRH2 protein expression was associated with a CD19+CD27+ memory cell phenotype. ANGPT2 plasma concentrations were twofold higher in the poor prognosis subgroup (P<0.05). Pim2 was significantly overexpressed in poor prognosis cases and Binet stage C. Disease progression may be related to proangiogenic processes and strong Pim2 expression.
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 ALL blasts whereas no surface immunoreactivity for CXCR5, CCR5 and CCR6 was observed. By contrast, non-Hodgkin's lymphomas (NHLs) corresponding to more mature peripheral B cell subsets (ie B-CLL and MCL) exhibited high expression levels of CXCR4 and CXCR5. Analysis of terminally differentiated myeloma cells revealed a down-regulation of CXCR4, CXCR5 and CCR6. CCR5, which is not expressed in normal B cells, was also absent from the majority of NHLs. However, CCR5 staining was seen in three of five cases of HCL, representing the first example of cross-lineage aberrant chemokine receptor expression in malignant haemopoietic cells.
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