bluuebunny/crossref_metadata_2025_split huggingface dataset:
Somatic Expansion of the Frataxin Gene GAA Repeats in MDS Patients.
Authors: Merkel Drorit , Deeg H. Joachim , Simon Amos , Amariglio Ninette , Nagler Arnon , Rechavi Gideon 
Published: April 2020

Abstract
The mitochondria play an important role in both apoptosis and heme synthesis. In patients with Myelodysplastic syndrome (MDS) the marrow is characterized by defective hematopoiesis, increased apoptosis and the presence of iron laden mitochondria. The molecular mechanisms responsible for increased apoptosis remain incompletely understood. Frederic’s ataxia (FRDA), the most common inherited ataxia, is a severe autosomal-recessive disease characterized by neurodegeneration, cardiomyopathy and diabetes, resulting from reduced synthesis of the mitochondrial protein frataxin which is involved in mitochondrial energy production and other cellular functions by providing iron for heme synthesis and iron–sulfur cluster (ISC) assembly and repair, serving as a Fe (II) donor for ferrochelatase. The underlying mutation consists of an unstable expansion of GAA repeats in the first intron of the frataxin gene. Long expansions of a GAA tri-nucleotide in FRDA patients range from 66 to more than 1,700 repeats, whereas the normal range of repeats varies from 7 to 36. Abnormal expansion results in reduced frataxin mRNA levels, leading to reduced function of the respiratory chain. The aim of the present study was to determine if frataxin gene mutations occurred in MDS patients. We analyzed DNA from peripheral blood (PB) of 29 MDS patients and from 22 healthy marrow (BM) donors using repeat-Primed PCR. We also sampled genomic DNA products from buccal smears of the MDS patients. In MDS patients PCR of PB in 9 out of 24 patients (37%) showed short length (2–8 repeats), whereas PB of the remaining 15 patients (62.5%) showed longer PCR products (10–43 repeats, still in the “normal” range for FRDA). The PCR products of the buccal smears from all 14 patient samples were short (2–7 repeats), including those from 9 patients who had longer repeats in PB. In healthy BM donors, PCR of PB detected short length repeats (4–5 repeats) in17 of 20 individuals (85%), whereas 3 samples (15%) had longer PCR products (11–26 repeats). This was statistically significantly different from patients with MDS (P= 0.0014). The results indicate that MDS patients exhibit longer frataxin gene products than healthy individuals in PB, but not in buccal DNA. These data suggest a somatic mutation in the frataxin gene in hematopoetic cells of patients with MDS. Further studies will explore the impact of this mutation on mitochondrial function and on the pathophysiology of MDS.
Trogocytosis in Multiple Myeloma.
Authors: Brown Ross D. , Kabani Karieshma , Yang Shihong , Esther Aklilu , Ho Phoebe Joy , Gibson John , Joshua Douglas E. 
Published: April 2020

Abstract
Trogocytosis is the transfer of cell membrane material from one cell to another during short term cell-cell contact. Recent studies have suggested that the transfer of cell membrane patches across the immunological synapse is at least partly responsible for immune tolerance, tumor escape and the production of adaptive T regulatory cells (Tregs). We sought to identify the extent of tumor-related trogocytosis in patients with multiple myeloma and have developed an in vitro model for further study. Trogocytosis in patients with multiple myeloma was demonstrated by flow cytometry, immunohistochemistry, confocal microscopy, lack of mRNA expression and by the failure to upregulate costimulatory molecules in vitro after stimulation by IL2 and huCD40LT. Of the costimulatory molecules CD80, CD86, B7-H1, B7-H3 and PD-L2, only CD80 and CD86 showed significant transfer to T cells. Increased CD80 expression was found on the T cells of 9% of patients and CD86 on 13% of patients (n= 95). Both CD4 and CD8 memory (CD45RO+) cells were involved but not naïve T cells (CD45RA+). HLA-G expression was found on less than 1% of T cells in 69/70 different myeloma blood samples. Following biotinylation of plasma cells (CD38++) using an in vitro culture model, trogocytosis was demonstrated in up to 36% of T cells. The presence of trogocytosis on CD3- TCRαβ-mutant Jurkat cells (J.RT3-T3.3) and on normal T cells with HLA incompatibility infers that trogocytosis is independent of immune recognition and TCR engagement. In vitro stimulation with IL-2 and huCD40LT and mRNA studies showed that T cells acquire CD80 and CD86 cell surface antigen but unlike B cells do not produce CD80 and CD86 mRNA (n=5) and cannot be stimulated to express CD80 and CD86 (n=6). Trogocytosis was not evident in age-matched control lymphocytes but could be induced in normal lymphocytes in vitro after exposure to malignant plasma cells. Trogocytosis is common in patients with multiple myeloma and involves the transfer of costimulatory molecules and other cell membrane proteins from malignant plasma cells to T cells. Tumor-induced trogocytosis may be a common cause of the failure of cytotoxic T cells and provide a mechanism of tumor escape.
Myeloma and Osteolytic Bone Disease: Is DKK1 All It Takes?.
Authors: Chen Bangzheng , Wu Hong , Zeng Yuxin , Freeman John E , Herman Damir , Shaughnessy John D. , Barlogie Bart , Epstein Joshua 
Published: April 2020

Abstract
The Dickkopf-1 (DKK1) gene product inhibits osteoblast activity by blocking Wnt signaling. Elevated levels of DKK1 in bone marrow plasma and peripheral blood are associated with the presence of osteolytic bone lesions in patients with multiple myeloma (Tian E, et al. N Engl J Med.2003, 349:2483), evidently by inhibiting osteoblast differentiation and, as a result, stimulating osteoclastogenesis driven by osteoblast progenitors’ enhanced production of RANKL and reduced expression of OPG. DKK1-neutralizing antibody suppressed bone resorption induced by inflammatory joint disease and myeloma in murine models (Diarra, Nature Medicine2007, 13:156, Yaccoby, Blood2007, 109:2106), and ectopic Wnt3a expression prevented myeloma induced bone resoption (Qiang, Blood2008;112:374). To further investigate whether DKK1 is essential for producing myeloma bone disease, we used 5 myeloma cell lines with various expression levels of DKK1 in our SCID-hu model. U266 and CAG cells, which express minimal amounts of DKK1 mRNA by qRT-PCR corresponding to 5ng/ml in spent media by ELISA, caused severe bone resorption, whereas ARP1, H929 and OPM2 which express 55, 61, and 320 fold higher levels of DKK1 mRNA (and 80 ng/ml protein for ARP1 cells) had no effects on the bones. OPM2 cells overexpressing DKK1 following transduction with lentiviral vector (127 fold higher than U266 cells), also did not cause bone resorption. To understand if the lack of relationship between DKK1 expression by myeloma cell lines and bone resorption reflected the level of expression, we used the prostate cancer cell line PC3 that expresses 100 times higher DKK1 mRNA than DKK1-transduced OPM2 cells. These cells caused severe bone destruction in the SCID-hu model. DKK1 expression by PC3 was inhibited by 80% by constitutive or conditional (tet-on) shRNA-lentivirus, and resulted in corresponding reduction (75%, p=0.02) in loss of bone mineral density compared with control cells transduced with conditional or constitutive control shRNA lentivirus. PC3 cells recovered from the tumors had 50% reduced levels of DKK1 mRNA. Myeloma associated osteolytic bone disease results from inhibition of osteoblast differentiation, resulting in reduced bone formation and overcharged osteoclastogenesis by osteoblast progenitors. It thus appears that a quantitative threshold exists below which DKK1 inhibition of Wnt is not sufficient to cause osteolytic bone disease. Alternatively, it is possible that the DKK1 produced by the MM cell lines is not funtional, or that factors other than inhibition of Wnt signaling by DKK1 can also be responsible for producing osteolytic bone disease. We are currently investigating whether direct stimulation of osteoclastic activity by the myeloma cell lines that cause osteolysis but express low DKK1 can explain this observed discrepancy, or if they inhibit osteoblast differentiation by other mechanisms. This work was supported in part by NIH grant CA55816.
High-Throughput Microrna Profiling in Patients with Waldenstrom’s Macroglobulinemia.
Authors: Adamia Sophia , Amin Samir B , Li Cheng , Patterson Christopher J , AvetLoiseau Herve , Minvielle Stephane , Moreau Philippe , Anderson Kenneth C , Munshi Nikhil C. , Treon Steven 
Published: April 2020

Abstract
Waldenström’s macroglobulinemia (WM) is an incurable B cell malignancy characterized by the accumulation of IgM secreting clonally related bone marrow lymphoplasmacytic cells (LPC) including CD19+ B-cells and CD138+ plasma cells. Despite intense research efforts, the pathogenetic basis for this disease remains to be clarified. MicroRNAs are small noncoding RNAs that regulate the expression of protein-coding genes by inducing translational inhibition and through cleavage of targeted transcripts by partial or complete base pairing. We therefore evaluated the expression of 384 microRNAs in CD19+ and CD138+ sorted bone marrow lymphoplasmacytic from 13 untreated WM patients, and compared their expression profiling to analogous lymphoplasmacytic cells taken from the bone marrows of 13 healthy donors. Data obtained from microRNA arrays was analyzed using SDS, RQ manager, R and dChip softwares. Relative expression was calculated using the comparative Ct method through RQ manager and dChip softwares. Of the 384 microRNAs evaluated in CD19+ patient cells, miR-192, -125b, -21, -155 demonstrated significant upregulation, whereas miR-181c, -572, and -650 were significantly down regulated compared to healthy donor CD19+ bone marrow cells (p&lt;0.05). Analysis of bone marrow derived CD138+ cells from WM patients demonstrated significant upregulation in miR-192, -193b, -17-3p, -585, -148b, whereas miR-29c, -155, -126, -148a, -125a, -181d, -30a-3p, let-7b, let-7c were downregulated in comparison to healthy donor CD138+ bone marrow cells (p&lt;0.05). Importantly, characterization of the modulated microRNAs found in these studies demonstrated a critical role in growth and survival pathways through modulation of several genes including HOX, BCL-2 and c-myc. Taken together, these studies demonstrate significant differences in microRNA expression between comparable WM and healthy donor lymphoplasmacytic cell populations, and identify aberrancies in microRNAs with a pivotal role in the growth and survival of B-cells.
The Parthenolide Derivative LC-1 Is An Effective Single Agent and Is Highly Synergistic with Existing Therapies in Multiple Myeloma.
Authors: Walsby Elisabeth J , Hewamana Saman , Burnett Alan , Knapper Steven , Fegan Chris , Pepper Chris 
Published: April 2020

Abstract
Multiple myeloma (MM) remains incurable with conventional therapeutic agents and has a median survival of only 3–5 years. Therefore, there is clearly a need for novel treatment strategies that can change the natural pathology of this condition. The nuclear factor κB (NF-κB) family of transcription factors is constitutively activated in MM cell lines and the majority of MM patients. Since NF-κB has known oncogenic activity in a number of human malignancies, targeted inhibition of this family of proteins may be useful in the treatment of MM. We and others have recently shown that the parthenolide derivative LC-1 has activity in acute myeloid leukaemia (AML) and chronic lymphocytic leukaemia (CLL) cells. Unusually, it induces apoptosis via the activation of both the intrinsic and extrinsic pathways and apoptosis is preceded by marked inhibition of NF-κB. Importantly, LC-1 is more potent against primary AML blasts and CLL lymphocytes than normal bone marrow progenitors and normal B-cells and T-cells. In this study we set out to evaluate LC-1 in MM cell lines and plasma cells derived from MM patients. LC-1 was cytotoxic to MM cell lines H929, U266 and JJN3 and induced apoptosis in a dosedependent manner resulting in an overall LD50 of 3.6mM (±1.8) after 48 hours in culture. Primary myeloma plasma cells, identified by CD38 and CD138 positivity, had a mean LD50 for LC-1 of 5.4mM (±1.6) after 48 hours of in vitro culture. Normal bone marrow cells were significantly less sensitive to the effects of LC-1 under the same conditions (P = 0.0007). Treatment of MM cell lines with LC-1 resulted in a decrease in the nuclear localization of NF-κB, as evidenced by a dose-dependent decrease in the DNA binding capacity of the NF-κB subunit RelA after 4 hours of treatment. To demonstrate whether synergy exists between LC-1 and existing MM therapies, the H929 cell line was treated for 48 hours with LC-1 and doxorubicin (32:1), melphalan (1:1) or bortezimib (1:500) and the combination indices (CI) calculated using the median effect method. A combination index of less than 1 denotes synergy. LC-1 did not show synergy with doxorubicin (CI &gt;1) but was synergistic with melphalan and bortezimib (CI values of 0.53 and 0.59 respectively). Taken together our data clearly demonstrate that LC-1 has activity in MM cell lines and primary MM cells. Its ability to inhibit the nuclear localization of NF-κB is important to its cytotoxic effects. Furthermore, it may also provide an explanation for the synergy demonstrated with melphalan and bortezimib. These results provide a rationale for exploring the potential of LC-1 in clinical studies.
Therapeutic Antimyeloma Effect of Dendritic-Tumor Cells Hybrids Transduced with Adenovirus Encoding CD40L.
Authors: Alvarez Eva , Moga Esther , Sierra Jorge , Briones Javier 
Published: April 2020

Abstract
Dendritic cells (DCs) are the main antigen presenting cells and play a pivotal role in the stimulation of T-cell immune responses. DCs cultured in the presence of a single tumor antigen can elicit an immune response against tumor cells expressing that antigen. However, simultaneous use of several tumor antigens may be advantageous since polyclonal activation of T cells against different tumor antigens may be a better approach to eradicate tumor cells. In this sense, fusions of dendritic and tumor cells (FCs) show a broad spectrum of tumor antigens, both known and unidentified, to be presented by class I and II MHC. Although prophylactic vaccines were successful in murine models, the results in the therapeutic setting have been unsatisfactory. We hypothesised that enhancing costimulation of FCs would help to break tumor tolerance once the tumor is established. To this purpose, we transduced FCs with a recombinant adenovirus encoding CD40L (AdvCD40L or AdvGFP as control) and we studied the therapeutic antitumoral effect of the administration of FC-CD40L in a murine model of myeloma. DCs obtained from day 7-bone marrow cultures of Balb/c mice were fused with tumor cells, a syngeneic murine myeloma cell line (4TOO). FCs hybrids were generated with PEG and selected after culturing in HAT medium plus GM-CSF for 7 days. FC were quantified by determining the percentage of cells that coexpress specific DC (CD11c) and tumor markers (CD138). Mean fusion efficiency was 30% (20–40%) and FCs expressed moderate levels of CD80, CD83, CD86, CD54, CD40 and MHC II and did not express CD40L. FC-CD40L showed a significant increase of expression of costimulatory molecules (CD80, CD86, CD54, and MHC II) compared to FC-GFP (p=0.011). Moreover, in a syngeneic mixed lymphocyte reaction, FC-CD40L induced a two-fold higher T-cell proliferation than FC-GFP or FC alone. In addition, FC-CD40L had improved migration to lymphoid tissues, preferentially to spleen, in comparison with FC-GFP (2.8% versus 1.6%). The antitumor effect of FC-CD40L was analyzed in vivo. Mice (n=10 per group) were injected i.v. with 2.5×105 tumor cells and treated with irradiated FC, FC-GFP or FC-CD40L (1×106 cells each) on days 2, 6 and 10 after tumor challenge. 40% of mice treated with FC-CD40L had long-term survival (&gt;120 days). In contrast, all of mice treated with FC or FC-GFP died between days 25 and 35 (p=0.012). In parallel, treatment with mixed cells (not fused DC+ tumor cells), mix transduced with AdvGFP, or mix transduced with AdvCD40L did not provide any significant antitumor effect. We conclude that FCs transduced with AdvCD40L better stimulate in vitro and in vivo immune responses than FC alone and may provide a new strategy for treating patients with multiple myeloma or lymphoma.
Short-Term Culture of Umbilical Cord Blood-Derived Stem Cells Enhances the Engraftment into NOD/SCID Mice through the Increased Expression of CXCR4.
Authors: Ohno Norioki , Kajiume Teruyuki , Sera Yoshihiko , Sato Takashi , Kobayashi Masao 
Published: April 2020

Abstract
Human umbilical cord blood (CB) is rich source of hematopoietic stem cells (HSCs) and provides an attractive alternative to bone marrow or mobilized peripheral blood transplantation. However, major disadvantage of CB transplantation is the relatively low number of HSCs in each CB unit, which severely limits its usefulness in clinical transplantation. A part of CD34+ cells expresses cell surface CXCR4, which has been found to be critical for bone marrow engraftment by human hematopoietic stem cells. In the present study, we examined the effect of short-term culture on CXCR4 expression and engraftment in CB-derived CD34+ cells transplanted into non-obese diabetic/severe combined immunodeficient (NOD/SCID) mice. CB-derived CD34+-enriched samples were divided into three aliquots and cultured. The first aliquot was incubated for 2 h in RPMI-1640 medium alone, whereas the second was incubated for 2h in RPMI-1640 medium containing the specific CXCR4 antagonist, AMD3100. As a control, the third sample was neither treated nor incubated. Surface CXCR4 expression on CD34+ cells significantly increased after incubating the cells in medium alone for 2 h (7.7 to 19.8%); this increase was blocked by the addition of AMD3100. No difference in CXCR4 mRNA expression was noted after incubating CD34+ cells for 2 h. The short-term incubation seems to influence the translocation of CXCR4 from the interior of the cell to the cell surface. CD34+ cells cultured for 2 h showed significantly increased transmigrational activity toward SDF-1 and homing activity in NOD/SCID mice. However, those were lower in non-cultured cells and cells treated with AMD3100. Next, we assessed the engraftment of cells cultured into NOD/SCID mice. Engraftment analysis was performed 8 weeks after transplantation. The presence of human cells was detected by the cell surface expression of CD45, CD34, CD33, and CD19. The CD34+ cells cultured demonstrated significantly increased engraftment of human cells in the bone marrow of NOD/SCID mice compared with that of CD34+ cells without culture or with culture in the presence of AMD3100 (p &lt; 0.01). The recipients exhibited CD19+ B-lymphoid cells, CD33+ myeloid cells, and CD34+ immature cells, but neither CD3+ T cells nor CD45+ cells in bone marrow. Finally, we performed a secondary transplant of engrafted cells from previously transplanted mice to confirm long-term engraftment and self-renewal of cultured CB cells. The successful engraftment was observed in mice injected with primary cultured cells, demonstrating that these cultured cells are self-renewing and capable of long-term engraftment. These observations suggest that the increase of the cell surface expression of CXCR4 on CD34 cells resulted in the retention of human umbilical cord blood cells within the bone marrow through the engraftment of homing activity.
Absolute Lymphocyte Count at the Time of Relapse Predicts Survival in Patients with Diffuse Large B-Cell Lymphoma.
Authors: Porrata Luis F. , Ristow Kay , Haberman Thomas M , Witzig Thomas E , Inwards David James , Ansell Stephen M , Johnston Patrick B , Micallef Ivana N. , Colgan Joseph P , White William L , Markovic Svetomir N 
Published: April 2020

Abstract
The International Prognostic Index at the time of relapse (IPI-R) has been reported to predict clinical outcome in patients with relapsed diffuse large B-cell lymphoma (DLBCL) undergoing autologous stem cell transplantation (ASCT) [Jabbour et al, Leukemia & Lymphoma2005;46(6):861–867; Lerner et al, Biology of Blood and Marrow Transplant2006;13:486–492; and Costa et al, Bone Marrow Transplant2008;41:715–720]. The absolute lymphocyte count (ALC) has been reported as a prognostic factor for survival at diagnosis, during standard chemotherapy and at day 15 post-ASCT for multiple hematological malignancies; however, no reports have addressed whether ALC at the time of relapse (ALC-R) predicts survival. Thus, we assessed the prognostic significance of ALC-R in patients with relapsed DLBCL. To be included in the study, patients were required to have been diagnosed with relapsed DLBCL, have ALC values available from the time of relapse, and to be followed at Mayo Clinic, Rochester. From Feb 2,1987 until March 6, 2006, 121 DLBCL patients qualified for the study. The overall survival (OS) was measured from the time of relapse to the date of death or last follow-up and progression-free survival (PFS) was defined as the time from relapse to the time of progression, relapse, death, or last follow-up. The median age at relapse was 68 years (range:25–88 years) and the median ALC-R was 1.21 x 109/L (range: 0.33–5.99 x 109/L). The value of ALC-R ≥ 1.0 x 109/L was used for the analysis based on previous publications. The groups (ALC-R ≥ 1 or &lt; 1 x 109/L) were balanced for the IPI-R (p=0.1), as well as for undergoing ASCT (p=0.4). Superior OS was observed in patients with an ALC-R ≥ 1.0 x 109/L (N = 76) [median OS: 27.5 months, 3 years OS rates of 42%] compared with patient with an ALC-R &lt; 1.0 x 109/L (N =45) [median OS: 9.4 months, 3 years OS rates of 13%] (p &lt;0.0001). Superior PFS was also observed in patients with an ALC-R ≥ 1.0 x 109/L (N = 76) [median PFS: 14.8 months, 3 years PFS rates of 30%] compared with patient with an ALC-R &lt; 1.0 x 109/L (N =45) [median PFS: 6.2 months, 3 years PFS rates of 11%] (p &lt;0.001). ALC-R was an independent prognostic factor for OS [RR = 0.551, p &lt; 0.009] and PFS [RR = 0.674, p &lt; 0.02] in the multivariate analysis when compared with the IPI-R and whether patients underwent ASCT or not. Our study supports the hypothesis that ALC at relapse predicts clinical outcome in DLBCL and suggests that patient host immunity is an important variable predicting survival in relapsed DLBCL.