bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement of HSP90 and HSP70 in CD34-Positive Cells: Lower Levels in Myelodysplastic Syndrome Than in Acute Myeloid Leukemia and Correlation with Clinical Behavior.
Authors: Gorre M. , Jilani I. , Chang R. , Chan H. , Urcia R. , Keating M. , Kantarjian H. , Estey E. , O’Brien S. , Giles F. , Albitar M. 
Published: April 2020

Abstract
Heat shock proteins (HSPs) are molecular chaperones involved in binding and regulating the levels of several client cellular proteins. HSPs are induced by stress and play a role in the modulation of apoptosis and proliferation. Expression of HSPs by acute myeloid leukemia (AML) cells has been reported to correlate with more aggressive disease. Here we used a flow cytometry approach to quantify the expression of HSP90 and HSP70 in specific cell populations in bone marrow. Quantification using QuantiBRITE and PE (phycoerythrin)-labeled antibodies with a 1:1 ratio allowed us to specifically measure the antibody binding capacity in 100 CD34+ cells (molecules/100 CD34+ or CD3+ cells). Using this approach, we compared bone marrow samples from patients with myelodysplastic syndrome (MDS) and patients with AML. This approach can also be used to monitor patients treated with therapeutic agents that target HSPs, such as 17-allylamino-17-demethoxygeldamycin (17AAG). The percentage of CD34+ cells expressing HSP90 (P=0.008) and HSP70 (P&lt;0.001) was significantly lower in MDS (n=20) than in AML (n=33) patients. Similarly, the percentage of CD3+ cells expressing HSP90 and HSP70 was significantly higher in MDS than in AML patients (P&lt;0.01). This suggests that the environment in the bone marrow (cytokines, chemokines, other factors) may affect the levels of HSPs in neoplastic and normal cells in a similar fashion. In patients with MDS, higher levels of HSP90 were associated with shorter survival (P=0.03). However, after achieving remission (CR), MDS patients who expressed high levels of HSP90 had significantly longer remission duration (CRD) (P=0.03). These findings not only confirm that the environment and blasts in patients with MDS are different from those in patients with AML, but also suggest that therapy targeting HSPs may be a rational approach in patients with MDS.
Figure Figure
Lenalidomide Selectively Inhibits In Vitro Growth of the Malignant Clone in Myelodysplastic Syndrome (MDS) Patients with 5q Deletion.
Authors: Jädersten Martin , Pellagatti Andrea , Forsblom Ann-Mari , Emanuelsson Emma K. , Merup Mats , Samuelsson Jan , Wainscoat James S. , Boultwood Jacqueline , Hellström-Lindberg Eva 
Published: April 2020

Abstract
The immunomodulatory drug lenalidomide induces 82% complete cytogenetic remissions in patients with myelodysplastic syndrome (MDS) and 5q31 deletion. Lenalidomide has multiple effects, but the causal mechanisms of action are unknown. In this study we assessed the direct effect of lenalidomide on hematopoietic cells from eight MDS patients with del(5)(q31) and from five healthy controls. Lenalidomide titrated up to 500 μM caused no growth inhibition of mononuclear cells from healthy controls. Selected CD34+ hematopoietic stem cells were then cultured with or without 10 μM of lenalidomide in a 14-day model for pure erythroblast differentiation in a medium containing IL-3, IL-6, and SCF, and with addition of Epo during the second week. Cell count and viability was monitored regularly, and FISH and FACS analyses were performed at day 0, 7, and 14. The median proportion of 5q- cells by FISH at day 7 was 98% (range 86–99), dropping to 88% (range 35–98) at day 14 due to a variable outgrowth of cytogenetically normal cells. Day 7 cells, the majority still being 5q-, were used for gene expression analyses. In erythroblast cultures with cells from healthy controls, lenalidomide had no inhibitory effect on fold increase of cell counts (P=0.92). However, in cultures with cells from 5q- patients, the clone with 5q deletion showed significant inhibition of fold increase at day 14 (P=0.009), while the cytogenetically normal progenitors were not inhibited (P=0.83). Gene expression profiling was performed using Affymetrix Human Genome U133 Plus 2.0 Arrays. A group of genes was found whose expression was affected by the addition of lenalidomide to the cultures of both normal erythroblasts and 5q- erythroblasts. Furthermore, lenalidomide decreased the proportion of cells expressing late erythroid markers on FACS analysis at day 14. We conclude that lenalidomide selectively inhibits in vitro growth of 5q- hematopoietic stem cells, while not affecting growth of cytogenetically normal cells from MDS patients with 5q deletion or from healthy controls. In addition, we see that lenalidomide affects cell differentiation and induces changes in gene expression.
Identification of Pathogenetically Important Genes within the Common Deleted Region (CDR) of the 5q- Syndrome.
Authors: Lehmann Soren , Raynaud Sophie , Desmond Julian C. , Koeffler Phillip H. 
Published: April 2020

Abstract
The 5q- syndrome is characterized by refractory anemia, normal or high platelet count, hypolobulated megakaryocytes, a good prognosis and a low risk of leukemic transformation. Although the CDR has been defined to a 1.5 Mb interval on the long arm on chromosome 5 (5q33.1), the molecular pathogenesis of the disease is still unknown. The CDR contains 39 known-genes of which 33 have been shown to be expressed in hematopoietic stem cells. In order to elucidate the molecular mechanisms behind the 5q- syndrome, we performed real-time quantitative PCR on these 33 genes. Samples from the bone marrow of 12 patients with a sole deletion of 5q and 14 patients with MDS with normal karyotype were initially analyzed. The genes that showed the most pronounced decrease in expression in the 5q- samples were: SLC36A1 (89% down-regulated compared to non 5q-), G3BP (79%), ATOX1 (76%), CSF1R (76%), RPS14 (74%), PDGFRB (73%), TNIP1 (72%), SPARC (71%), ANAX6 (69%), NSDT (66%) and TIGD (60%). SPARC expression was found to be higher in both types of MDS samples compared to normal bone marrow (n=18) as well as compared to seven leukemic cell lines (HL-60, NB4, HEL, KG1, K562, U937 and TP-1). ATOX1 expression was highly over-expressed (20- to 80-fold) in the leukemic cell lines and modestly but significantly higher in normal bone marrow compared to both types of MDS. For G3BP, the expression was similar in normal bone marrow compared to the non-5q- samples but 1- to 10-fold higher in the cell lines. RPS14 was down-regulated in both types of MDS compared to normal bone marrow and leukemic cell lines. Thus, we have identified the most significantly down-regulated genes within the CDR of the 5q- syndrome. Based on our expression data, their known biological functions and on publicly available tissue expression data, genes such as G3BP, ATOX1, TNIP1, RPS14 and CSF1R are interesting targets for further studies. Biological studies are currently being performed on these genes with respect to their role during hematopoiesis with special focus on erythropoiesis.
TNF-α Stimulates Matrix Metalloproteinase Expression in Myelodysplastic Syndromes (MDS): Therapeutic Potential for Inhibitors of TNF-α and MMPs.
Authors: Janowska-Wieczorek A. , Marquez-Curtis Leah A. , Gan Kenton , Larratt Loree , Woods Anthony 
Published: April 2020

Abstract
MDS is characterized by ineffective hematopoiesis with increased intramedullary apoptosis which has been correlated in turn with high levels of tumor necrosis factor (TNF)- α. Previously, we showed that TNF-α strongly upregulates the secretion of the matrix metalloproteinases (MMP)-2 and -9 in normal CD34+ cells. Elevated expression of MMPs has been suggested to contribute to cancer progression and leukemic dissemination and MMPs also facilitate the secretion of TNF-α. In this work, we hypothesized that TNF-α-induced MMP production plays a role in the progression of MDS. We therefore examined the effects of recombinant human (rh) TNF-α on the expression and secretion of MMP-2, MMP-9 and membrane type (MT) 1-MMP (known activator of MMP-2), by MNC from MDS patients (using RT-PCR, zymography and Western blotting), as well as the effects of TNF-α on migration of MDS MNC across the reconstituted basement membrane Matrigel. We observed higher mean levels of TNF-α in media conditioned by mononuclear cells (MNC) obtained from 20 patients diagnosed with MDS (RAEB-T (4); RAEB (5), RA (10) and RARS (1)) in comparison to normal controls. We found that (i) MMP-9 is secreted by MDS MNC and this secretion is increased by TNF-α, (ii) MT1-MMP is expressed by the majority of MDS MNC and this expression is upregulated by TNF-α, and (iii) MMP-2 is detectable only in RAEB-T MNC samples and is activated by TNF-α. TNF-α also stimulated the migration of MDS MNC across Matrigel, which was inhibited by the inhibitor of MT1-MMP, epigallocatechin-3-gallate. Moreover, Enbrel (soluble TNF receptor fusion protein), which blocks TNF-α, also inhibited the expression of MT1-MMP and secretion of MMP-9 by MDS MNC as well as their migration across Matrigel. In addition, we observed increased activation of the latent form of MMP-2 in co-cultures of MDS MNC with bone marrow fibroblastic cells. We suggest that in MDS patients, TNF-α stimulates the expression of MMP-9 and MT1-MMP, inducing a highly proteolytic environment in bone marrow which could further increase processing and secretion of endogenous TNF-α. Therefore, we suggest that use of TNF-α inhibitors combined with MMP inhibitors could have therapeutic value in abrogating the progression of MDS.
SD-208, a Novel Transforming Growth Factor Beta Receptor I Kinase Inhibitor, Can Stimulate Hematopoiesis in Myelodysplastic Syndrome Progenitors.
Authors: Verma Amit , Navas Tony A. , Ying Jing , Nguyen Aaron N. , Pahanish Perry , Seetharam Mahesh , Kerr Irene , Collins Robert , Kim Mimi , Mohindru Mani , Higgins Linda S. 
Published: April 2020

Abstract
Transforming Growth Factor β (TGF-β) is a myelosuppressive cytokine that has been implicated in the ineffective hematopoiesis seen in myelodysplastic syndromes (MDS). Overactivation of TGF-β signaling in this disease was demonstrated immunohistochemically by significantly higher nuclear SMAD2 phosphorylation observed in 20 MDS bone marrows when compared with 7 non MDS anemic controls (P &lt; 0.0001, 2 Tailed T Test, Image Pro Plus software). This data along with high levels of membrane-bound and plasma TGF-β observed in MDS patients in previous studies support the development of therapeutics targeting the TGF-β signaling pathways in this disease. SD-208 is a novel, potent and specific inhibitor of TGF-β Receptor I (TGFβ-RI) kinase. We demonstrate that SD-208 blocks the phosphorylation of SMAD2 in hematopoietic progenitors which are at the colony forming unit-erythroid (CFU-E) stage of differentiation. SD-208 also abrogates the G0/G1 cell cycle arrest induced by TGF-β in bone marrow progenitors. SD-208 treatment leads to reversal of the myelosuppressive effects of TGF-β on erythroid and myeloid colony formation from primary human CD34+ cells. Selectivity of SD-208 in inhibiting TGF-β-mediated effects on hematopoiesis was supported by similar results observed with siRNAs targeting SMAD2, a major component of the TGF-b signaling pathway. Finally, the efficacy of SD-208 in MDS was evaluated by treating bone marrow mononuclear cells from 15 patients with early low grade MDS. SD-208 treatment led to dose-dependent increases in erythroid and myeloid colonies after 14 days of in vitro culture. The effect was most notable in patients with high levels of activated SMAD-2, as assessed by immunohistochemical staining of bone marrow biopsies. Stimulation of hematopoiesis in MDS-derived marrow culture by SD-208 demonstrates a novel concept and potential therapeutic role for TGFβ-RI inhibition in this disease. Supported by VISN-17 grant, Harris Methodist Foundation Grant and ASCO YIA to AV
Predictive Factors for Response and Progression after Treatment with Rituximab in Previously Untreated Patients with Waldenstrom’s Macroglobulinemia (WM).
Authors: Anagnostopoulos Athanasios , Treon Steven P. , Zervas Konstantinos , Branagan Andrew , Gika Dimitra , Zomas Athanasios , Kyrtsonis Marie Christine , Vassou Amalia , Anagnostopoulos Nikolaos , Pangalis Gerasimos , Dimopoulos Meletios A. 
Published: April 2020

Abstract
Introduction: Rituximab is an active agent for the treatment of WM. However many patients do not respond to this agent and several others develop secondary resistance. The purpose of this study was to identify clinical and laboratory parameters which could predict a higher likelihood of benefit in previously untreated WM patients who received treatment with rituximab.
Patients and methods: We evaluated clinical and laboratory characteristics of 35 patients with WM who received primary treatment with single agent rituximab. We correlated these characteristics with response to treatment and time to progression.
Results: Between 8/98 and 12/03, 35 WM patients, median age 68 (range 39–90), 24 male, received primary treatment with extended rituximab as previously described (Dimopoulos et al, JCO 2002 and Treon et al, Ann Oncol 2005). Anemia (Hgb&lt;10g/dL) was present in 55%, thrombocytopenia (PLT&lt;100,000/mm3) in 31%, lymphadenopathy in 40%, splenomegaly, hyperviscosity and B-symptoms were present in 17% of the patients each. 43% of the patients had M-peak levels 4gr/dL, 37% had albumin &lt;3.5g/dL and 56% had 2 microglobulin &gt;3,5mg/dL. Fifteen patients (43%) achieved at least 50% reduction of M-peak and of tumor infiltrates at all involved sites. Patients with Hg10 g/dL and monoclonal kappa light chain had a significantly higher probability to respond [65% vs 22% (pvalue 0.01) and 50% vs 10 % (p value 0,037) respectively]. Patients with higher albumin and lower serum M-peak levels had also a higher frequency of response (p=0,15 and 0,09 respectively). After a median follow-up of 43 months, 19 patients have progressed, (5 responders and 14 non responders) with a median PFS of 23,6 months for the whole patient population and not reached for the responders (75% without progression at 26 months). In the univariate analysis the most important factor predicting longer PFS was hemoglobin 10gr/dL (median 57,8 vs 5,4 months). Other factors associated with longer PFS was albumin 3,5gr/L (median 25,5 vs 5,3 months), serum M-peak &lt;4gr/L (48 vs 6,2), absence of hyperviscosity (23 vs 3,5) and presence of k light chain (25,4 vs 5,1).
Conclusion: Our analysis which included a large number of patients with long-term follow-up indicates that primary treatment with rituximab is associated with objective response in 43% of patients with WM and with a median PFS of 2 years. Patients most likely to benefit from rituximab include those without significant anemia, with k light chain, with lower levels of M-peak and with higher levels of albumin.
Increased Marrow CD57+ Cytotoxic T Cells Is a Powerful Prognostic Marker for Survival in Patients with Relapsed Multiple Myeloma (MM) Receiving Thalidomide.
Authors: Mileshkin Linda R. , Gambell Peter , Beshay Victoria , Hayakawa Yoshihiro , Smyth Mark , Trivett Melanie , Simmons Paul J. , Milner Alvin , Zeldis Jerome B. , Prince Miles 
Published: April 2020

Abstract
Background: In vitro studies indicate that thalidomide alters the marrow microenvironment and also has an immunoregulatory role. We assessed various laboratory and clinical parameters to examine potential prognostic markers and to assess for changes during thalidomide therapy.
Methods: 75 patients with relapsed/refractory MM were enrolled in a multi-centre phase 2 trial using thalidomide (Blood. 2003;102:69–77). Platelet-poor plasma (PPP) and marrow biopsy were obtained at baseline and 3 monthly and immunohistochemistry for CD34, VWF, mast cell tryptase and CD57 performed. Flow cytometry on marrow aspirates was used to define the CD57+ population (T cell subsets, NK, NKT markers used). Vascular endothelial growth factor (VEGF), basic-Fibroblast growth factor (bFGF), interleukin-6 (IL-6) and Hepatocyte growth factor (HGF) were measured in PPP. Objectives were to examine for effect on response rate (RR), progression-free (PFS) and overall survival (OS).
Results: Overall RR was 28% with 55% stable disease. Only VEGF predicted response-no responses seen in patients with a level of 0, compared to a RR of 34% in those with VEGF &gt; 0 (p=0.015). Microvessel density (MVD) did not predict for response, PFS or OS. The median number of CD57+ cells at baseline was 3 per HPF (range: 0–27) and flow cytometry confirmed that CD57+ cells were predominantly cytotoxic T cells. CD57+ cells did not predict for response, however on univariate analysis elevated levels were the major predictor of better OS (p=0.003). Predictors for inferior OS were raised baseline levels of IL-6 (p=0.014), and HGF (p=0.016). Multivariate analysis for OS which incorporated clinical variables demonstrated age &gt;65 yrs (p=0.009), raised LDH (p=0.008) and zero baseline CD57+ cells (p=0.011) as predictors of inferior OS. MVD and VEGF fell significantly in responding patients although CD57+ cells did not change.
Conclusion: Levels of VEGF and MVD decline in thalidomide responders. However, high baseline angiogenic activity was not necessary to obtain a response. Increased age and elevated LDH are important predictors of poorer OS, with elevated baseline levels of CD57+ cells being an independent predictor of superior outcome.
Juxtamembrane Domain Truncation Is Sufficient for Activation of the FIP1L1-PDGFRα and ETV6-PDGFRβ Fusion Kinases.
Authors: Stover Elizabeth H. , Chen Jing , Folens Cedric , Lee Benjamin H. , Mentens Nicole , Marynen Peter , Gilliland D. Gary , Cools Jan 
Published: April 2020

Abstract
Tyrosine kinase fusions such as BCR-ABL are common causes of myeloproliferative diseases and hematopoietic malignancies. Frequently, enforced dimerization by the fusion partner protein confers ligand-independent activation on these fusion kinases. FIP1L1-PDGFRα is a fusion kinase implicated in chronic eosinophilic leukemia and systemic mast cell disease. Recently, we showed that the partner protein FIP1L1 is not, in fact, required for PDGFRα activation in vitro or in vivo. We now demonstrate that truncation of the PDGFRα juxtamembrane (JM) domain is sufficient for kinase activation and subsequent transformation of Ba/F3 cells to growth factor independence, even in the absence of FIP1L1. In contrast, the presence of a complete JM domain is inhibitory to PDGFRα kinase activation. These findings are consistent with clinical data from patients with the FIP1L1-PDGFRα fusion, in which the breakpoints in PDGFRA are always tightly clustered within the JM domain. Furthermore, our results suggest that disruption of the JM domain, which has an autoinhibitory function in some type III receptor tyrosine kinases (RTKs), may contribute to activation of chimeric kinases. Notably, we observed a similar effect of JM domain truncation in a related type III RTK, PDGFRβ. Fusion of PDGFRB to various partner proteins, such as ETV6, can cause chronic myelomonocytic leukemia. However, we show that PDGFRβ kinase activation and signaling to downstream targets can be achieved in the absence of ETV6 via truncation of PDGFRB within the JM domain. These results suggest that disruption of an autoinhibitory JM domain may be an alternative, dimerization-independent mechanism of aberrant regulation of activated kinases involved in hematopoietic and other malignancies.
Identification of Mcl-1 as a Novel Target in Neoplastic Mast Cells and Demonstration of Cooperative Growth-Inhibitory Effects of mcl-1 Antisense Oligonucleotides, PKC412, and AMN107.
Authors: Aichberger Karl J. , Mayerhofer Matthias , Gleixner Karoline V. , Krauth Maria-Theresa , Derdak Sophia , Pickl Winfried F. , Wacheck Volker , Selzer Edgar , Agis Hermine , Sillaber Christian , Valent Peter 
Published: April 2020

Abstract
Mcl-1 is a Bcl-2 family-member that has been described to act anti-apoptotic in various myeloid neoplasms and therefore has been proposed as a potential therapeutic target. Systemic mastocytosis (SM) is a myeloid neoplasm involving myelomastocytic progenitors. We examined the expression and functional role of Mcl-1 in neoplastic mast cells (MC), to determine whether Mcl-1 could serve as a target in MC neoplasms. As assessed by RT-PCR and immunohistochemistry, primary neoplastic MC were found to express Mcl-1 mRNA and the Mcl-1 protein in a constitutive manner in all patients analyzed. Moreover, the human MC-leukemia cell line HMC-1 was found to express Mcl-1. Transfection of these cells with Mcl-1-specific antisense oligonucleotides (ASO) or an mcl-1-specific siRNA using lipofectin resulted in a reduced survival and increased percentage of apoptotic cells compared to control. The effects of mcl-1 ASO were seen with the HMC-1.1 subclone carrying the G560V c-kit mutation (mcl-1 ASO, 250 nM: 49±4% apoptotic cells compared to control: 3±2%, p&lt;0.05; mcl-1 siRNA: 41±5% vs control: 5±3%, p&lt;0.05) as well as with HMC-1.2 cells carrying both the G560V c-kit mutation and the D816V c-kit mutation (mcl-1 ASO, 250 nM: 36±2% apoptotic cells compared to control: 6±1%, p&lt;0.05; mcl-1 siRNA: 30±6% vs control: 5±2%, p&lt;0.05). Moreover, mcl-1 ASO were found to cooperate with the tyrosine kinase inhibitors (Novartis Pharma AG) imatinib, AMN107, and PKC412 in producing growth inhibition in HMC-1.2 cells. Together, these data show that Mcl-1 is a novel survival factor and attractive target in neoplastic human MC. Whether the Mcl-1-targeting concept can be developed far enough to reach clinical application remains to be elucidated.
Inhibition of Growth of Neoplastic Mast Cells by CD44 mAb A3D8 Is Associated with G1 Cell Cycle Arrest and Apoptosis.
Authors: Boehm Alexandra , Florian Stefan , Gleixner Karoline , Sonneck Karoline , Aichberger Karl J. , Derdak Sophia , Pickl Winfried F. , Valent Peter , Sperr Wolfgang R. 
Published: April 2020

Abstract
Recent data suggest that CD44 may serve as a new therapeutic target in AML and possibly also in other myeloid neoplasms. Systemic mastocytosis (SM) is a myeloid neoplasm characterized by abnormal growth and accumulation of mast cells (MC) in one or multiple organs. We have previously shown that normal tissue MC express CD44. In the present study, we asked whether CD44 is expressed on neoplastic human MC and whether CD44-ligation by the monoclonal antibody (mAb) A3D8 would be associated with inhibition of growth of neoplastic MC. As assessed by flow cytometry, primary neoplastic MC were found to express CD44 in all patients with SM analyzed (n=10). The human mast cell leukemia (MCL) cell line HMC-1 was also found to express CD44. As assessed by 3H-thymidine incorporation, the CD44 mAb A3D8 decreased the proliferation of HMC-1 cells in a dose-dependent manner (A3D8, 5 μg/ml: 46±26% of control=100%, p&lt;0.05). Similar effects of A3D8 were observed with primary neoplastic MC obtained from a patient with MCL (A3D8, 5 μg/ml: 68±20%) and one with smouldering SM (A3D8, 2.5 μg/ml: 42±7% of control, p&lt;0.05). To analyze the mechanism of A3D8-induced growth inhibition, cell survival and cell cycle distribution were analyzed. We found that CD44-ligation induces an approximately 3-fold increase in apoptotic HMC-1 cells compared to control. As assessed by flow cytometry, we were also able to demonstrate that A3D8 induces cell cycle arrest in the G1-phase. Moreover, as assessed by Western blotting, we found that incubation of HMC-1 cells with mAb A3D8 results in an increase in the cyclin-dependent kinase-inhibitor p27Kip1. In summary, our results suggest that CD44-ligation is followed by inhibition of growth of neoplastic human MC through induction of apoptosis and G1 cell cycle arrest. The latter is probably mediated by stabilization of p27Kipl. Whether targeting of CD44 in neoplastic MC in patients with high grade MC disorders is of clinical significance remains to be determined in forthcoming studies.