Showing papers in "Leukemia in 2007"
TL;DR: The European Study Group on MRD detection in ALL (ESG-MRD-ALL), consisting of 30 MRD-PCR laboratories worldwide, has developed guidelines for the interpretation of real-time quantitative PCR-based MRD data.
Abstract: Most modern treatment protocols for acute lymphoblastic leukaemia (ALL) include the analysis of minimal residual disease (MRD). To ensure comparable MRD results between different MRD-polymerase chain reaction (PCR) laboratories, standardization and quality control are essential. The European Study Group on MRD detection in ALL (ESG-MRD-ALL), consisting of 30 MRD-PCR laboratories worldwide, has developed guidelines for the interpretation of real-time quantitative PCR-based MRD data. The application of these guidelines ensures identical interpretation of MRD data between different laboratories of the same MRD-based clinical protocol. Furthermore, the ESG-MRD-ALL guidelines will facilitate the comparison of MRD data obtained in different treatment protocols, including those with new drugs.
648 citations
TL;DR: The present report expands the spectrum of knowledge showing that MS has frequent monoblastic/myelomonocytic differentiation, displays distinctive phenotypic profile, carries chromosomal aberrations other than t(8;21), and requires supra-maximal therapy.
Abstract: Myeloid sarcoma (MS) is a rare neoplasm whose knowledge is largely based on case reports and/or technically dated contributions. Ninety-two MSs in adulthood with clinical data available were evaluated both morphologically and immunohistochemically. Seventy-four cases were also studied by fluorescent in situ hybridization on tissue sections and/or conventional karyotyping on bone marrow or peripheral blood. Histologically, 50% of the tumors were of the blastic type, 43.5% either monoblastic or myelomonocytic and 6.5% corresponded to different histotypes. CD68/KP1 was the most commonly expressed marker (100%), followed by myeloperoxidase (83.6%), CD117 (80.4%), CD99 (54.3%), CD68/PG-M1 (51%), CD34 (43.4%), terminal-deoxy-nucleotidyl-transferase (31.5%), CD56 (13%), CD61/linker for activation of T cells (2.2%), CD30 (2.2%) and CD4 (1.1%). Foci of plasmacytoid monocyte differentiation were observed in intestinal cases carrying inv16. Chromosomal aberrations were detected in about 54% of cases: monosomy 7(10.8%), trisomy 8(10.4%) and mixed lineage leukemia-splitting (8.5%) were the commonest abnormalities, whereas t(8;21) was rare (2.2%). The behavior was dramatic irrespective of presentation, age, sex, phenotype and cytogenetics. Most if not all, long survivors received bone-marrow transplantation. The present report expands the spectrum of our knowledge showing that MS has frequent monoblastic/myelomonocytic differentiation, displays distinctive phenotypic profile, carries chromosomal aberrations other than t(8;21), and requires supra-maximal therapy.
556 citations
TL;DR: ATG provides multifaceted immunomodulation paving the way for future applications and suggesting that the use of ATG should be included in the immunosuppression therapeutic armamentarium to help reduce the incidence of organ rejection and GVHD.
Abstract: The success of allogeneic stem cell transplantation and solid-organ transplantation owes much to improvements in the immunosuppressive regimens that prevent graft-versus-host disease (GVHD) or suppress allograft rejection. A better understanding of the immune mechanisms underlying induction of immunological tolerance is the key to successful transplantation. Polyclonal antibodies such as antithymocyte globulins (ATG) have been used for decades. The common belief is that ATG efficacy relies on its capacity to deplete T lymphocytes. The aim of this review is to offer an overview of the recent findings that have been demonstrated in ATG's immunomodulatory activity. The polyclonal nature of ATG is reflected in its diverse effects on the immune system: (1) T-cell depletion in blood and peripheral lymphoid tissues through complement-dependent lysis and T-cell activation and apoptosis; (2) modulation of key cell surface molecules that mediate leukocyte/endothelium interactions; (3) induction of apoptosis in B-cell lineages; (4) interference with dendritic cell functional properties; and (5) induction of regulatory T and natural killer T cells. As a consequence, ATG provides multifaceted immunomodulation paving the way for future applications and suggesting that the use of ATG should be included in the immunosuppression therapeutic armamentarium to help reduce the incidence of organ rejection and GVHD.
492 citations
TL;DR: This review explores the literature supporting both views of WT1 in human cancer and in particular human leukemias and examines its functional activity as a transcription factor and the influence of protein partners on its dual behavior.
Abstract: The Wilms' tumor 1 (WT1) gene encodes a transcription factor important for normal cellular development and cell survival. The initial discovery of WT1 as the causative gene in an autosomal-recessive condition identified it as a tumor suppressor gene whose mutations are associated with urogenital disease and the development of kidney tumors. However, this view is not in keeping with the frequent finding of wild-type, full-length WT1 in human leukemia, breast cancer and several other cancers including the majority of Wilms' tumors. Rather, these observations suggest that in those conditions, WT1 has an oncogenic role in tumor formation. In this review, we explore the literature supporting both views of WT1 in human cancer and in particular human leukemias. To understand the mechanism by which WT1 can do this, we will also examine its functional activity as a transcription factor and the influence of protein partners on its dual behavior.
442 citations
TL;DR: Co-transplantation of MSC resulted in fast engraftment of absolute neutrophil count and platelets and 100% donor chimerism, even in three patients regrafted for graft failure/rejection.
Abstract: Transplantation of mesenchymal stem cells to enhance engraftment of hematopoietic stem cells
422 citations
TL;DR: The aim of this project was to identify situations where allogeneic stem cell transplantation (allo-SCT) might be considered as a preferred treatment option for patients with B-cell chronic lymphocytic leukemia (CLL).
Abstract: The aim of this project was to identify situations where allogeneic stem cell transplantation (allo-SCT) might be considered as a preferred treatment option for patients with B-cell chronic lymphocytic leukemia (CLL). Based on a MEDLINE search and additional sources, a consented proposal was drafted, refined and approved upon final discussion by an international expert panel. Key elements of the consensus are (1) allo-SCT is a procedure with evidence-based efficacy in poor-risk CLL; (2) although definition of 'poor-risk CLL' requires further investigation, allo-SCT is a reasonable treatment option for younger patients with (i) non-response or early relapse (within 12 months) after purine analogues, (ii) relapse within 24 months after having achieved a response with purine-analogue-based combination therapy or autologous transplantation, and (iii) patients with p53 abnormalities requiring treatment; and (3) optimum transplant strategies may vary according to distinct clinical situations and should be defined in prospective trials. This is the first attempt to define standard indications for allo-SCT in CLL. Nevertheless, whenever possible, allo-SCT should be performed within disease-specific prospective clinical protocols in order to continuously refine transplant indications according to new developments in risk assessment and treatment of CLL.
400 citations
TL;DR: By employing a novel two-step isolation procedure – removal of erythrocytes by hypotonic lysis combined with multiparameter sorting – this work could isolate from CB a population of human cells that are similar to murine BM-derived VSELs, described previously.
Abstract: Recently, we purified from adult murine bone marrow (BM) a population of CXCR4(+), Oct-4(+) SSEA-1(+), Sca-1(+) lin(-) CD45(-) very small embryonic-like (VSEL) stem cells and hypothesized that similar cells could be also present in human cord blood (CB). Here, we report that by employing a novel two-step isolation procedure -- removal of erythrocytes by hypotonic lysis combined with multiparameter sorting -- we could isolate from CB a population of human cells that are similar to murine BM-derived VSELs, described previously by us. These CB-isolated VSELs (CB-VSEL) are very small (3-5 micro m) and highly enriched in a population of CXCR4(+)AC133(+)CD34(+)lin(-) CD45(-) CB mononuclear cells, possess large nuclei containing unorganized euchromatin and express nuclear embryonic transcription factors Oct-4 and Nanog and surface embryonic antigen SSEA-4. Further studies are needed to see if human CB-isolated VSELs similar to their murine BM-derived counterparts are endowed with pluripotent stem cell properties.
375 citations
TL;DR: It is suggested that MSC have the ability to form a cancer stem cell niche in which tumor cells can preserve the potential to proliferate and sustain the malignant process.
Abstract: Mesenchymal stem cells (MSC) have received much attention in the field of hematopoietic stem cell transplantation because not only do they support hematopoiesis but also exhibit a profound immunosuppressive activity that can be exploited to prevent undesired alloreactivity. We have previously shown that their immunosuppressive activity is mainly exerted at the level of T-cell proliferation. Here, we show that MSC exhibit a similar antiproliferative activity on tumor cells of hematopoietic and non hematopoietic origin. In vitro, MSC produced the transient arrest of tumor cells in the G1 phase of cell cycle; this was accompanied by a reduction in the apoptotic rate even when survival factors were limiting. However, when tumor cells were injected into non-obese diabetic–severe combined immunodeficient mice in conjunction with MSC, their growth was much faster as compared to the group receiving only tumor cells. To explain the discrepancy between the in vitro and in vivo behavior, we suggest that MSC have the ability to form a cancer stem cell niche in which tumor cells can preserve the potential to proliferate and sustain the malignant process. We conclude that the clinical use of MSC in conditions in which a malignant disease is involved should be handled with extreme caution.
372 citations
TL;DR: It is shown that the lesser effect of imatinib mesylate on the 3-week output of cells produced in vitro from lin−CD34+CD38− CML (stem) cells compared with cultures initiated with the CD38+ subset of lin− CD34+ cells is markedly enhanced when conditions of reduced growth factor stimulation are used.
Abstract: The leukemic stem cells in patients with chronic myeloid leukemia (CML) are well known to be clinically resistant to conventional chemotherapy and may also be relatively resistant to BCR-ABL-targeted drugs. Here we show that the lesser effect of imatinib mesylate (IM) on the 3-week output of cells produced in vitro from lin(-)CD34(+)CD38(-) CML (stem) cells compared with cultures initiated with the CD38(+) subset of lin(-)CD34(+) cells is markedly enhanced (>10-fold) when conditions of reduced growth factor stimulation are used. Quantitative analysis of genes expressed in these different CML subsets revealed a differentiation-associated decrease in IL-3 and G-CSF transcripts, a much more profound decrease in expression of BCR-ABL than predicted by changes in BCR expression, decreasing expression of ABCB1/MDR and ABCG2 and increasing expression of OCT1. p210(BCR-ABL) and kinase activity were also higher in the lin(-)CD34(+)CD38(-) cells and formal evidence that increasing BCR-ABL expression decreases IM sensitivity was obtained from experiments with a cell line model. Nevertheless, within the entire CD34(+) subset of CML cells, BCR-ABL expression was not strongly affected by changes in cell cycle status. Taken together, these results provide the first evidence of multiple mechanisms of innate IM resistance in primitive and quiescent CML cells.
370 citations
TL;DR: The fact that the authors frequently encountered multiple lesions affecting genes involved in cell cycle regulation and B-cell differentiation strongly suggests that both these processes need to be targeted independently and simultaneously to trigger ALL development.
Abstract: Gross cytogenetic anomalies are traditionally being used as diagnostic, prognostic and therapeutic markers in the clinical management of cancer, including childhood acute lymphoblastic leukemia (ALL). Recently, it has become increasingly clear that genetic lesions driving tumorigenesis frequently occur at the submicroscopic level and, consequently, escape standard cytogenetic observations. Therefore, we profiled the genomes of 40 childhood ALLs at high resolution. We detected multiple de novo genetic lesions, including gross aneuploidies and segmental gains and losses, some of which were subtle and affected single genes. Many of these lesions involved recurrent (partially) overlapping deletions and duplications, containing various established leukemia-associated genes, such as ETV6, RUNX1 and MLL. Importantly, the most frequently affected genes were those controlling G1/S cell cycle progression (e.g. CDKN2A, CDKN1B and RB1), followed by genes associated with B-cell development. The latter group includes microdeletions of the B-lineage transcription factors PAX5, EBF, E2-2 and IKZF1 (Ikaros), as well as genes with other established roles in B-cell development, that is RAG1 and RAG2, FYN, PBEF1 or CBP/PAG. The fact that we frequently encountered multiple lesions affecting genes involved in cell cycle regulation and B-cell differentiation strongly suggests that both these processes need to be targeted independently and simultaneously to trigger ALL development.
365 citations
TL;DR: The proposed flow cytometry approach is applicable to all sample types and therapeutic regimes, and sufficiently rapid and sensitive to guide therapy to an MRD-negativity in real time, and may be used as a tool for assessing response and comparing the efficacy of different therapeutic approaches.
Abstract: The eradication of minimal residual disease (MRD) in chronic lymphocytic leukaemia (CLL) predicts for improved outcome. However, the wide variety of MRD techniques makes it difficult to interpret and compare different clinical trials. Our aim was to develop a standardized flow cytometric CLL-MRD assay and compare it to real-time quantitative allele-specific oligonucleotide (RQ-ASO) Immunoglobulin heavy chain gene (IgH) polymerase chain reaction (PCR). Analysis of 728 paired blood and marrow samples demonstrated high concordance (87%) for patients off-therapy. Blood analysis was equally or more sensitive than marrow in 92% of samples but marrow analysis was necessary to detect MRD within 3 months of alemtuzumab therapy. Assessment of 50 CLL-specific antibody combinations identified three (CD5/CD19 with CD20/CD38, CD81/CD22 and CD79b/CD43) with low inter-laboratory variation and false-detection rates. Experienced operators demonstrated an accuracy of 95.7% (specificity 98.8%, sensitivity 91.1%) in 141 samples with 0.01-0.1% CLL. There was close correlation and 95% concordance with RQ-ASO IgH-PCR for detection of CLL above 0.01%. The proposed flow cytometry approach is applicable to all sample types and therapeutic regimes, and sufficiently rapid and sensitive to guide therapy to an MRD-negativity in real time. These techniques may be used as a tool for assessing response and comparing the efficacy of different therapeutic approaches.
TL;DR: Additional abnormalities are detectable providing new biological insights into different CLL subclasses revealing a much more heterogeneous pattern of cytogenetic abnormalities as assumed so far based on FISH data only, and prospective clinical trials should evaluate the prognostic impact of newly available CBA data.
Abstract: In CLL data from chromosome banding analysis (CBA) have been scarce due to the low proliferative activity of CLL cells in vitro. We improved the cultivation technique using an immunostimulatory CpG-oligonucleotide DSP30 and IL-2. A total of 506 CLL samples were analysed with CBA and interphase FISH using probes for the detection of trisomy 12, IgH rearrangements and deletions of 6q21, 11q22.3 (ATM), 13q14 (D13S25 and D13S319) and 17p13 (TP53). A total of 500 of 506 (98.8%) cases were successfully stimulated for metaphase generation and are subject to this study. Aberrations were detected in 415 of 500 (83.0%) cases by CBA and in 392 of 500 (78.4%) cases by FISH. CBA detected 832 abnormalities and FISH only 502. Therefore, CBA offers important information in addition to FISH. (1) CLL is characterized mainly by genomic imbalances and reciprocal translocations are rare. (2) A subgroup with complex aberrant karyotype (16.4%) is identified which is associated with an unmutated IgV(H) status and CD38 expression (P=0.034 and 0.02, respectively). (3) Additional abnormalities are detectable providing new biological insights into different CLL subclasses revealing a much more heterogeneous pattern of cytogenetic abnormalities as assumed so far based on FISH data only. Therefore, prospective clinical trials should evaluate the prognostic impact of newly available CBA data.
TL;DR: A trend was seen towards decreased PBSC yield with increasing duration of lenalidomide therapy as well as increasing age, and there was no effect on quality of PBSC collected based on similar engraftment across all groups.
Abstract: While initial therapies have become highly effective with introduction of lenalidomide and bortezomib and patients may opt for delayed stem cell transplantation, it is important to collect stem cells for future transplant. Given its increasing use as initial therapy, we examined if lenalidomide had any impact on the ability to collect peripheral blood stem cells (PBSC). We studied the entire cohort of patients with myeloma undergoing PBSC mobilization at our institution during a 5-year period, comparing the results between patients receiving different initial therapies. Among those mobilized with granulocyte-colony stimulating factor (G-CSF) alone, there was a significant decrease in total CD34(+) cells collected (P<0.001), average daily collection (P<0.001), day 1 collection (P<0.001) and increased number of aphereses (P=0.004) in patients treated with lenalidomide compared to those receiving dexamethasone, thalidomide-dexamethasone or VAD. A similar trend was seen in those mobilized with chemotherapy and G-CSF. A trend was seen towards decreased PBSC yield with increasing duration of lenalidomide therapy as well as increasing age (P=0.002). There was no effect on quality of PBSC collected based on similar engraftment across all groups. We recommend collection of PBSC within 6 months of initiation of therapy with lenalidomide containing regimens to minimize the risk of mobilization failures.
TL;DR: It is concluded that a burden of JAK2V617F allele greater than 75% at diagnosis points to PV patients with high-risk disease.
Abstract: The aim of this study was to determine whether the burden of JAK2(V617F) allele correlated with major clinical outcomes in patients with polycythemia vera (PV). To this end, we determined JAK2 mutant allele levels in granulocytes of 173 PV patients at diagnosis. The mean (+/-s.d.) mutant allele burden was 52% (+/-29); 32 patients (18%) had greater than 75% mutant allele. The burden of JAK2(V617F) allele correlated with measurements of stimulated erythropoiesis (higher hematocrit, lower mean cell volume, serum ferritin and erythropoietin levels) and myelopoiesis (higher white cell count, neutrophil count and serum lactate dehydrogenase) and with markers of neutrophil activation (elevated leukocyte alkaline phosphatase and PRV-1 expression). As compared to those with less than 25% mutant allele, patients harboring greater than 75% JAK2(V617F) allele were at higher relative risk (RR) of presenting larger spleen (RR 4.7; P<0.001) or suffering from pruritus (RR 3.1; P<0.001). In these patients, the risk of requiring chemotherapy (RR 1.8; P=0.001) or developing major cardiovascular events (RR 7.1; P=0.003) during follow up were significantly increased. We conclude that a burden of JAK2(V617F) allele greater than 75% at diagnosis points to PV patients with high-risk disease.
TL;DR: Bone marrow mesenchymal stem cells, the only long-lived cells of the bone marrow microenvironment, are abnormal and could create a very efficient niche to support the survival and proliferation of the myeloma cells.
Abstract: Recent literature suggested that cells of the microenvironment of tumors could be abnormal as well. To address this hypothesis in multiple myeloma (MM), we studied bone marrow mesenchymal stem cells (BMMSCs), the only long-lived cells of the bone marrow microenvironment, by gene expression profiling and phenotypic and functional studies in three groups of individuals: patients with MM, patients with monoclonal gamopathy of undefined significance (MGUS) and healthy age-matched subjects. Gene expression profile independently classified the BMMSCs of these individuals in a normal and in an MM group. MGUS BMMSCs were interspersed between these two groups. Among the 145 distinct genes differentially expressed in MM and normal BMMSCs, 46% may account for a tumor-microenvironment cross-talk. Known soluble factors implicated in MM pathophysiologic features (i.e. IL (interleukin)-6, DKK1) were revealed and new ones were found which are involved in angiogenesis, osteogenic differentiation or tumor growth. In particular, GDF15 was found to induce dose-dependent growth of MOLP-6, a stromal cell-dependent myeloma cell line. Functionally, MM BMMSCs induced an overgrowth of MOLP-6, and their capacity to differentiate into an osteoblastic lineage was impaired. Thus, MM BMMSCs are abnormal and could create a very efficient niche to support the survival and proliferation of the myeloma cells.
TL;DR: This review will attempt to outline the definition of EPCs from some of the most widely cited published reports in an effort to provide a framework for understanding subsequent studies in this rapidly evolving field.
Abstract: Since 1997, postnatal vasculogenesis has been purported to be an important mechanism for neoangiogenesis via bone marrow (BM)-derived circulating endothelial progenitor cells (EPCs). Based on this paradigm, EPCs have been extensively studied as biomarkers to assess severity of cardiovascular disease and as a cell-based therapy for several human cardiovascular disorders. In the majority of studies to date, EPCs were identified and enumerated by two primary methodologies; EPCs were obtained and quantified following in vitro cell culture, or EPCs were identified and enumerated by flow cytometry. Both methods have proven controversial. This review will attempt to outline the definition of EPCs from some of the most widely cited published reports in an effort to provide a framework for understanding subsequent studies in this rapidly evolving field. We will focus this review on studies that used cell culture techniques to define EPCs.
Radboud University Nijmegen1, University of Amsterdam2, Drug Abuse Resistance Education3, Instituto Português de Oncologia Francisco Gentil4, University College London5, University of Wales6, Nottingham City Hospital7, University of Aberdeen8, University of Cambridge9, Charité10, University of Göttingen11, Necker-Enfants Malades Hospital12, Erasmus University Rotterdam13
TL;DR: B-cell clonality was detected by combined use of the IGH and IGK multiplex PCR assays in all 260 definitive cases of B-cell chronic lymphocytic leukemia, mantle cell lymphoma, marginal zone lymphoma and follicular lymphoma.
Abstract: Polymerase chain reaction (PCR) assessment of clonal immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements is an important diagnostic tool in mature B-cell neoplasms. However, lack of standardized PCR protocols resulting in a high level of false negativity has hampered comparability of data in previous clonality studies. In order to address these problems, 22 European laboratories investigated the Ig/TCR rearrangement patterns as well as t(14;18) and t(11;14) translocations of 369 B-cell malignancies belonging to five WHO-defined entities using the standardized BIOMED-2 multiplex PCR tubes accompanied by international pathology panel review. B-cell clonality was detected by combined use of the IGH and IGK multiplex PCR assays in all 260 definitive cases of B-cell chronic lymphocytic leukemia (n=56), mantle cell lymphoma (n=54), marginal zone lymphoma (n=41) and follicular lymphoma (n=109). Two of 109 cases of diffuse large B-cell lymphoma showed no detectable clonal marker. The use of these techniques to assign cell lineage should be treated with caution as additional clonal TCR gene rearrangements were frequently detected in all disease categories. Our study indicates that the BIOMED-2 multiplex PCR assays provide a powerful strategy for clonality assessment in B-cell malignancies resulting in high Ig clonality detection rates particularly when IGH and IGK strategies are combined.
TL;DR: JAK2 exon 12 mutations in PV cases are found to be readily detected by both DNA sequencing and AS-PCR, regardless of whether BM or peripheral blood cells were used as the source for DNA.
Abstract: After accounting for misdiagnosis and treatment effect, allele-specific (AS)-PCR detects the JAK2V617F mutation in >95% of polycythemia vera (PV) patients. Using database inquiry, we identified 6 of a total 220 cases with PV that were JAK2V617F-negative (prevalence=3%). Of these, five cases ( approximately 80%) were found to harbor one of the two JAK2 exon 12 mutations (F537-K539delinsL or N542-E543del) in bone marrow (BM) and/or peripheral blood cells. Similar screening of six additional cases - three each with idiopathic erythrocytosis (IE) or otherwise unexplained erythrocytosis (UE) - did not reveal either JAK2V617F or JAK2 exon 12 mutations. We found JAK2 exon 12 mutations in PV cases to be readily detected by both DNA sequencing and AS-PCR, regardless of whether BM or peripheral blood cells were used as the source for DNA. Although erythroid hyperplasia was the predominant histologic feature on BM examination, megakaryocyte abnormalities and reticulin fibrosis were noted in most PV patients harboring exon 12 mutations. However, similar BM morphologic changes can also be seen in some JAK2V617F-positive PV cases; therefore, distinct genotype-phenotype association cannot be established.
TL;DR: TG101209, an orally bioavailable small molecule that potently inhibits JAK2, FLT3, RET and RET kinases, with significantly less activity against other tyrosine kinases including JAK3 and RET as mentioned in this paper.
Abstract: JAK2V617F and MPLW515L/K represent recently identified mutations in myeloproliferative disorders (MPD) that cause dysregulated JAK-STAT signaling, which is implicated in MPD pathogenesis We developed TG101209, an orally bioavailable small molecule that potently inhibits JAK2 (IC50=6 nM), FLT3 (IC50=25 nM) and RET (IC50=17 nM) kinases, with significantly less activity against other tyrosine kinases including JAK3 (IC50=169 nM) TG101209 inhibited growth of Ba/F3 cells expressing JAK2V617F or MPLW515L mutations with an IC50 of ∼200 nM In a human JAK2V617F-expressing acute myeloid leukemia cell line, TG101209-induced cell cycle arrest and apoptosis, and inhibited phosphorylation of JAK2V617F, STAT5 and STAT3 Therapeutic efficacy of TG101209 was demonstrated in a nude mouse model Furthermore, TG101209 suppressed growth of hematopoietic colonies from primary progenitor cells harboring JAK2V617F or MPL515 mutations
TL;DR: The participants of the BIOMED-2 Concerted Action CT98-3936 report on the validation of the newly developed clonality assays in various disease entities, which can now be implemented in routine lymphoma diagnostics.
Abstract: The diagnosis of malignant lymphoma is a recognized difficult area in histopathology. Therefore, detection of clonality in a suspected lymphoproliferation is a valuable diagnostic criterion. We have developed primer sets for the detection of rearrangements in the B- and T-cell receptor genes as reliable tools for clonality assessment in lymphoproliferations suspected for lymphoma. In this issue of Leukemia, the participants of the BIOMED-2 Concerted Action CT98-3936 report on the validation of the newly developed clonality assays in various disease entities. Clonality was detected in 99% of all B-cell malignancies and in 94% of all T-cell malignancies, whereas the great majority of reactive lesions showed polyclonality. The combined BIOMED-2 results are summarized in a guideline, which can now be implemented in routine lymphoma diagnostics. The use of this standardized approach in patients with a suspect lymphoproliferation will result in improved diagnosis of malignant lymphoma.
TL;DR: Matched-pairs analyses suggest that bortezomib may overcome some of the poor impact of del(13) as an independent prognostic factor, however, sample sizes were very small; these findings require confirmation from further studies.
Abstract: In multiple myeloma, deletion of chromosome 13 (del(13)) is associated with poor prognosis regardless of treatment. This study analyzed the impact of del(13) status on response and survival following treatment with either bortezomib or high-dose dexamethasone in patients in the SUMMIT and APEX trials. Additionally, matched-pairs subset analyses were conducted of patients with and without del(13), balanced for age and International Staging System parameters. In both SUMMIT and APEX, prognosis appeared to be poorer in bortezomib-treated patients with del(13) compared with patients with no del(13) by metaphase cytogenetics. In the SUMMIT and APEX matched-pairs analysis, response and survival appeared comparable in bortezomib-treated patients with or without del(13) by metaphase cytogenetics. However, patients with del(13) receiving dexamethasone in APEX appeared to have markedly decreased survival compared with those without del(13) by metaphase cytogenetics. These matched-pairs analyses suggest that bortezomib may overcome some of the poor impact of del(13) as an independent prognostic factor. However, sample sizes were very small; these findings require confirmation from further studies.
TL;DR: Estimation of expression levels of a selected group of haematopoietic tissue-specific miRNAs revealed that miR-181a correlated strongly with the AML morphological sub-type and with the expression of genes previously identified through sequence analysis as potential interaction targets.
Abstract: MicroRNAs (miRNAs) are short single-stranded RNAs that have a potentially important role in gene regulation. Using a quantitative real-time polymerase chain reaction assay specific to the mature miRNA, the expression level of a selected group of haematopoietic tissue-specific miRNAs was measured across a set of 30 primary adult acute myeloid leukaemia (AML) with a normal karyotype. The expression levels of each miRNA were correlated with the genome-wide mRNA expression profiles in the same leukaemias. This revealed that miR-181a correlated strongly with the AML morphological sub-type and with the expression of genes previously identified through sequence analysis as potential interaction targets. Three other miRNAs, miR-10a, miR-10b and miR-196a-1, showed a clear correlation with HOX gene expression.
TL;DR: Mylotarg administered in fractionated doses demonstrated an excellent efficacy/safety profile and a re-expression of CD33 antigenic sites on the cell surface of blasts cells after exposure to GO was observed.
Abstract: Pivotal phase II studies in acute myeloblastic leukemia (AML) patients in first relapse have used gemtuzumab ozogamicin (GO) (Mylotarg) at a dose of 9 mg/m(2) on days 1 and 14. These studies showed a 26% response rate (13% complete remission (CR) and 13% CRp (complete remission with incomplete platelet recovery)) but with high degree of hematological and liver toxicities. Based on in vitro studies showing a re-expression of CD33 antigenic sites on the cell surface of blasts cells after exposure to GO, we hypothesized that fractionated doses of GO may be efficient and better tolerated. Fifty-seven patients with AML in first relapse received GO at a dose of 3 mg/m(2) on days 1, 4 and 7 for one course. Fifteen patients (26%) achieved CR and four (7%) CRp. Remission rate correlated strongly with P-glycoprotein and MRP1 activities. The median relapse-free survival was 11 months, similar for CR or CRp patients. Median duration of neutropenia < 500/microl and thrombocytopenia < 50,000/microl were, respectively, 23 and 21 days. No grade 3 or 4 liver toxicity was observed. No veno-occlusive disease occurred after GO or after hematopoietic stem cell transplantation given after GO in seven patients. Mylotarg administered in fractionated doses demonstrated an excellent efficacy/safety profile.
TL;DR: It is concluded that most adult patients with recurring ALL could not be rescued using current available therapies, although allogeneic SCT remains the best therapeutic option.
Abstract: Fifty-four percent of adults with acute lymphoblastic leukemia (ALL) who entered the LALA-94 trial experienced a first relapse. We examined the outcome of these 421 adult patients. One hundred and eighty-seven patients (44%) achieved a second complete remission (CR). The median disease-free survival (DFS) was 5.2 months with a 5-year DFS at 12%. Factors predicting a better outcome after relapse were any transplant performed in second CR (P 1 year (P=0.04) and platelet level >100 x 10(9)/l at relapse (P=0.04). Risk groups defined at diagnosis and treatment received in first CR did not influence the outcome after relapse. The best results were obtained in a subset of patients who were eligible for allogeneic stem cell transplantation (SCT). Geno-identical allogeneic SCT was performed in 55 patients, and 3 patients received donor lymphocyte infusions. Forty-four transplantations were performed from an unrelated donor (of which four were cord blood). We conclude that most adult patients with recurring ALL could not be rescued using current available therapies, although allogeneic SCT remains the best therapeutic option.
TL;DR: It is hypothesized that SSCloALDHbr cells in ALDH+AML might denote primitive LSC and confer an inferior prognosis in patients and was significantly associated with adverse cytogenetic abnormalities.
Abstract: Aldehyde dehydrogenase (ALDH) activity is used to define normal hematopoietic stem cell (HSC), but its link to leukemic stem cells (LSC) in acute myeloid leukemia (AML) is currently unknown. We hypothesize that ALDH activity in AML might be correlated with the presence of LSC. Fifty-eight bone marrow (BM) samples were collected from AML (n=43), acute lymphoblastic leukemia (ALL) (n=8) and normal cases (n=7). In 14 AML cases, a high SSC(lo)ALDH(br) cell population was identified (ALDH(+)AML) (median: 14.89%, range: 5.65-48.01%), with the majority of the SSC(lo)ALDH(br) cells coexpressing CD34(+). In another 29 cases, there was undetectable (n=23) or rare (< or =5%) (n=6) SSC(lo)ALDH(br) population (ALDH(-)AML). Among other clinicopathologic variables, ALDH(+)AML was significantly associated with adverse cytogenetic abnormalities. CD34(+) BM cells from ALDH(+)AML engrafted significantly better in NOD/SCID mice (ALDH(+)AML: injected bone 21.11+/-9.07%; uninjected bone 1.52+/-0.75% vs ALDH(-)AML: injected bone 1.77+/-1.66% (P=0.05); uninjected bone 0.23+/-0.23% (P=0.03)) with the engrafting cells showing molecular and cytogenetic aberrations identical to the original clones. Normal BM contained a small SSC(lo)ALDH(br) population (median: 2.92%, range: 0.92-5.79%), but none of the ALL cases showed this fraction. In conclusion, SSC(lo)ALDH(br) cells in ALDH(+)AML might denote primitive LSC and confer an inferior prognosis in patients.
TL;DR: The presence of stem cells in adult tissues including bone marrow, epidermis, bronchial epithelium, myocardium, pancreas and testes supports the concept that adult tissues contain some population of pluripotent stem cells that is deposited in embryogenesis during early gastrulation.
Abstract: Accumulating evidence demonstrates that adult tissues contain a population of stem cells that express early developmental markers such as stage-specific embryonic antigen and transcription factors Oct-4 and Nanog. These are the markers characteristic for embryonic stem cells, epiblast stem cells and primordial germ cells. The presence of these stem cells in adult tissues including bone marrow, epidermis, bronchial epithelium, myocardium, pancreas and testes supports the concept that adult tissues contain some population of pluripotent stem cells that is deposited in embryogenesis during early gastrulation. In this review we will discuss these data and present a hypothesis that these cells could be direct descendants of the germ lineage. The germ lineage in order to pass genes on to the next generations creates soma and thus becomes a 'mother lineage' for all somatic cell lineages present in the adult body.
TL;DR: An overview of the biological effects that have been involved in proteasome inhibitors' antitumor activity is offered and prospective future applications for these drugs based on their recently characterized anti-inflammatory and immunomodulatory effects are suggested.
Abstract: Proteasome inhibitors are emerging as effective drugs for the treatment of multiple myeloma and possibly certain subtypes of non-Hodgkin's lymphoma Bortezomib (Velcade) is the first proteasome inhibitor proven to be clinically useful and will soon be followed by a second generation of small molecule inhibitors with improved pharmacological properties Although it is now understood that certain types of malignancies have an exquisite dependence on a functional proteasome for their survival, the underlying reason(s) remain unclear as of now In this context, addiction to nuclear factor-kappaB (NF-kappaB)-induced survival signals, activation of the unfolded protein response as well as a reduced proteasomal activity in differentiated plasma cells have all been proposed to justify proteasome inhibitors' activity in susceptible tissues In addition to their anticancer properties, bortezomib and related drugs modulate inflammatory and immune responses by affecting function and survival of immune cells such as lymphocytes and dendritic cells The present review offers an overview of the biological effects that have been involved in proteasome inhibitors' antitumor activity and suggests prospective future applications for these drugs based on their recently characterized anti-inflammatory and immunomodulatory effects
TL;DR: ERIC recommendations on IGHV gene mutational status analysis in chronic lymphocytic leukemia and recommendations on how to proceed with this analysis are published.
Abstract: ERIC recommendations on IGHV gene mutational status analysis in chronic lymphocytic leukemia
University of Kiel1, University of Southampton2, University of Salamanca3, Instituto Português de Oncologia Francisco Gentil4, Goethe University Frankfurt5, Cardiff University6, University of Münster7, Erasmus University Rotterdam8, Royal Free Hospital9, Nottingham City Hospital10, Charité11, Necker-Enfants Malades Hospital12
TL;DR: This study indicates that the BIOMED-2 multiplex PCR tubes provide a powerful strategy for clonality assessment in T- cell malignancies assisting the firm diagnosis of T-cell neoplasms.
Abstract: Polymerase chain reaction (PCR) assessment of clonal T-cell receptor (TCR) and immunoglobulin (Ig) gene rearrangements is an important diagnostic tool in mature T-cell neoplasms. However, lack of standardized primers and PCR protocols has hampered comparability of data in previous clonality studies. To obtain reference values for Ig/TCR rearrangement patterns, 19 European laboratories investigated 188 T-cell malignancies belonging to five World Health Organization-defined entities. The TCR/Ig spectrum of each sample was analyzed in duplicate in two different laboratories using the standardized BIOMED-2 PCR multiplex tubes accompanied by international pathology panel review. TCR clonality was detected in 99% (143/145) of all definite cases of T-cell prolymphocytic leukemia, T-cell large granular lymphocytic leukemia, peripheral T-cell lymphoma (unspecified) and angioimmunoblastic T-cell lymphoma (AILT), whereas nine of 43 anaplastic large cell lymphomas did not show clonal TCR rearrangements. Combined use of TCRB and TCRG genes revealed two or more clonal signals in 95% of all TCR clonal cases. Ig clonality was mostly restricted to AILT. Our study indicates that the BIOMED-2 multiplex PCR tubes provide a powerful strategy for clonality assessment in T-cell malignancies assisting the firm diagnosis of T-cell neoplasms. The detected TCR gene rearrangements can also be used as PCR targets for monitoring of minimal residual disease.
TL;DR: This review explores the literature supporting both views of WT1 in human cancer and in particular human leukemias and examines its functional activity as a transcription factor and the influence of protein partners on its dual behavior.
Abstract: Correction to: Leukemia (2007) 21, 868–876. doi:10.1038/sj.leu.2404624 Since the publication of the above article, the authors have identified a spelling error in Dr F Suarez Saiz name. The correct name is shown above. The authors apologize for any inconvenience caused.