bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early Results from a Phase II Study of Lenalidomide Monotherapy in Relapsed/Refractory Indolent Non-Hodgkin’s Lymphoma.
Authors: Witzig Thomas E. , Vose Julie M. , Kaplan Henry P. , Wolf Jeffrey Lee , Pietronigro Dennis , Takeshita Kenichi , Ervin-Haynes Annette , Zeldis Jerome B. , Wiernik Peter H. 
Published: October 2019

Abstract
Background: Lenalidomide (Revlimid®), an immunomodulatory drug (IMiD®), was recently approved in the US for treatment of relapsed/refractory multiple myeloma and myelodysplastic syndromes associated with a deletion 5q[31] cytogenetic abnormality. Lenalidomide also has demonstrated activity in chronic lymphocytic leukemia and cutaneous T-cell lymphoma while thalidomide, a less potent IMiD®, has activity in non-Hodgkin’s lymphoma (NHL) as both monotherapy and in combination with rituximab.
Aim: To assess the safety and efficacy of lenalidomide monotherapy in subjects with relapsed/refractory indolent NHL.
Methods: Subjects with relapsed/refractory indolent NHL following at least 1 prior treatment regimen with measurable disease are eligible. Subjects receive 25 mg lenalidomide orally once daily on Days 1–21 every 28 days and continue therapy for 52 weeks as tolerated or until disease progression. Response and progression are evaluated using the IWLRC methodology.
Results: As of July 25, 2006, 23 subjects of a planned 40 have enrolled and received drug. Fifteen subjects are currently evaluable for tumor response. The median age of the 15 response-evaluable subjects is 64 (54–82) and 5 are female. Histology is small lymphocytic lymphoma [SLL] (n=8), follicular center lymphoma grades 1,2 [FL] (n=5) and nodal marginal B-cell lymphoma [NML] (n=2). Median time from diagnosis to lenalidomide monotherapy is 7.6 (3–14) years and median number of prior treatment regimens per subject is 3 (1–17). Two subjects (13%) exhibited an objective partial response (PR) at four months. Both responses, one FL and one NML, occurred in subjects with substantial tumor burden of 61.8 cm2 and 80.3 cm2, respectively. The 4-month time-to-response for these indolent NHL subjects is longer than the 2-month median time-to-response in aggressive NHL subjects (n=7) following lenalidomide monotherapy. Seven patients had stable disease (SD) for a tumor control rate (TCR) of 60% and 6 had progressive disease (PD). Grade 3 or 4 adverse events occurred in 9 (39%) subjects. These were predominantly Grade 3 hematological events (neutropenia, thrombocytopenia) with only 3 subjects (13%) experiencing a Grade 4 adverse reaction (all neutropenia).
Conclusion: Early results of lenalidomide monotherapy in indolent NHL show evidence of activity with a safety profile similar to that established previously in other hematological malignancies.
The C3b Component of Complement Inhibits NK Cell Activation Induced by Rituximab-Coated Target Cells.
Authors: Wang Siao-Yi , Racila Emilian , Taylor Ronald P. , Weiner George J. 
Published: October 2019

Abstract
Rituximab (RTX) is an accepted therapy for B cell malignancies, but there is still much to learn about the mechanisms responsible for the observed responses and the potential interactions between various mechanisms of action. Some studies suggest that complement fixation followed by lysis through the membrane attack complex contributes to the anti-tumor effects of RTX. Other investigations indicate that antibody dependent cellular cytotoxicity (ADCC) mediated by NK cells is central to the response of therapy. In prior studies, we found that RTX-coated target cells activate NK cells as indicated by NK cell modulation of CD16, upregulation of CD54 and CD69, and production of IFNγ. NK activation induced by RTX-coated target cells was dependent on the affinity of multivalent interactions between Fc γ receptors III (CD16) of the NK cell and Fc regions of cell-bound RTX molecules. We used these in vitro assays to assess the relationship between complement fixation, and the ability of RTX-coated target cells to activate NK cells. Normal human serum inhibited the modulation of NK cell CD16, and also blocked upregulation of CD54, induced by RTX-coated target cells. The ability of serum to inhibit NK activation was dose dependent and was abrogated upon heat inactivation. Serum depleted of C1q or C3 also failed to inhibit NK cell activation. The inhibitory activity of serum depleted of these complement components was restored when purified C1q or C3 were added back respectively. In addition, the level of NK cell inhibition was dependent on the amount of C3b deposited on the target cells. An antibody that stabilizes C3b on the target cell surface (3E7, DiLillo et al., Molec Immunol 2006) further enhanced the inhibition of NK cell activation induced by RTX-coated target cells. One possible explanation for these findings is that complement-mediated lysis destroyed the RTX-coated target cells before they had the opportunity to induce activation of the NK cells. To assess this possibility, lymphoma cells were killed, fixed with formaldehyde, and washed prior to their use as target cells. These RTX-coated and fixed target cells were able to induce modulation of CD16 on the NK cells, which was again inhibited by normal human serum. These findings indicate that the observed inhibition of NK activation by complement is unlikely to be a consequence of complement mediated lysis of the target cells. Instead, these data suggest that C3b deposition on RTX-coated target cells inhibits the interaction between the Fc portions of RTX and CD16 on the NK cells, and so limits the ability of RTX-coated target cells to induce NK activation. These results could have implications in our understanding of the relationship between complement fixation and ADCC, and their relative roles in potentiating destruction of malignant cells in the blood and tissues.
MK-0457, a Novel Multikinase Inhibitor, Is Active in Patients with Chronic Myeloid Leukemia (CML) and Acute Lymphocytic Leukemia (ALL) with the T315I BCR-ABL Resistance Mutation and Patients with Refractory JAK-2 Positive Myeloproliferative Diseases (MPD).
Authors: Giles Francis , Cortes Jorge , Bergstrom Donald A. , Xiao Alan , Jones Dan , Verstovsek Srdan , Thomas Deborah , Kantarjian Hagop M. , Freedman Steven J. 
Published: October 2019

Abstract
MK-0457 (VX-680) is a small molecule inhibitor of aurora kinases A, B, and C, FLT3, and JAK-2 with nanomolar level broad spectrum pre-clinical anti-tumor activity. The T315I BCR-ABL mutation mediates high level resistance to imatinib, dasatinib and nilotinib. MK-0457 has in vitro activity against cells expressing wild-type or mutated BCR-ABL, including the T315I BCR-ABL mutation. A Phase I study of MK-0457 is being conducted in patients with refractory hematologic malignancies. The study regime is a 5-day continuous IV regimen given every 2 to 3 weeks. To date, dose levels of 8 (N=4), 12 (N=5), 16 (N=3), 20 (N=4), 24 (N=15), 28 (N=6), and 32 (N=3) mg/m2/hr have been investigated. No MK-0457-attributable extramedullary Grade 3 adverse events (AEs) have been observed to date, and thus, the maximum-tolerated dose (MTD) has not yet been reached. Grade 1 nausea was observed in 1 patient each at the 12 and 24 mg/m2/hr levels, and there have been 4 patients with Grade 1 alopecia. Dose-proportional PK has been observed across dose levels. Myelosuppression is consistently seen with MK-0457 at all dose levels studied to date and appears dose-related. Of 40 patients on study to date, 15 had CML, 2 had ALL, 13 had acute myeloid leukemia (AML), and 10 had rapidly progressive or transforming MPD. A nested PCR strategy followed by direct DNA sequencing using the dideoxy chain termination method was used to detect and monitor mutations in codons 221 to 500 of the BCR-ABL kinase domain in CML and ALL patients. Of 15 patients with CML, 11 had a T315I BCR-ABL mutation as had 1 of 2 ALL patients. Of 14 currently evaluable patients with CML, 11 had an objective (hematologic, cytogenetic, and/or molecular) response, including all 11 patients with the T315I mutation. The patient with T315I-mutant ALL also had an objective response. Six of 8 currently evaluable patients with JAK-2 positive refractory MPD have achieved an objective response. Downregulation of BCR-ABL and CrkL phosphorylation in leukemia cells from CML and ALL patients treated on study has been documented – the possible role of aurora kinase inhibition in these clinical responses requires further investigation. Accrual to the study is ongoing at the 36 mg/m2/hr dose level. The currently reported cases are the first observed clinical activity of a kinase inhibitor against the T315I positive CML/ALL and JAK-2 positive MPD. The observation of responses in these patients to doses of MK-0457 associated with no significant toxicity warrants further study.
Cancer Stem Cell Targeting in Multiple Myeloma by GRN163L, a Novel and Potent Telomerase Inhibitor.
Authors: Matsui William , Wang Qiuju , Vala Milada , Barber James P. , Meeker Alan , Tressler Robert , Harley Calvin , Huff Carol A. , Smith B. Douglas , Jones Richard J. 
Published: October 2019

Abstract
Telomerase activity (TA) is required within normal cells capable of long-term replication, including stem cells and is upregulated in many cancers. In the absence of TA or presence of TA inhibitors, the progressive shortening of telomeres ultimately results in cellular senescence and/or apoptosis. These observations support that TA inhibitors represent a novel class of anti-tumor agents. Much evidence suggests that human cancers display a hierarchical cellular organization that mirrors normal tissues. Cancer stem cells (CSC) are derived from the malignant transformation of normal stem cells and progenitors and retain the capacity to self-renew. Moreover, CSC give rise to differentiated tumor cells that form the bulk of the tumor mass, but have little or no capacity for long-term proliferation. We recently demonstrated that the malignant CD138+ plasma cells in multiple myeloma (MM) have limited replicative potential; instead they arise from the differentiation of clonogenic CSC that resemble normal memory B cells (CD138negCD19+CD27+). In addition, several groups have demonstrated that telomerase inhibitors are active against human MM cell lines in vitro and in vivo. We examined TA in CD138+ plasma cells and CD138neg precursors, and studied the effects of telomerase inhibition against both cell populations. We isolated CD138+ and CD138neg cells by FACS from three human MM cell lines (RPMI 8225, NCI-H929, and U266) and measured TA using a PCR-based assay of activity. For each cell line, TA was detectable within both the CD138neg and CD138+ cell populations. GRN163L is a lipid conjugated 13 nucleotide thio-phosphoramidate oligonucleotide that acts as a potent and specific active site inhibitor of telomerase. We found that treatment with GRN163L (0.1–5μM) markedly reduced TA within 48 hours. To examine the effects of telomerase inhibition on clonogenic growth, we continuously cultured CD138+ and CD138neg RPMI 8226 cells with GRN163L (1μM). Cells were collected weekly, washed to remove GRN163L, and then plated in methylcellulose to assess colony formation. We found that GRN163L was active against both CD138+ and CD138neg cells and eliminated the colony forming potential of both by 5 weeks. Similarly, we found that GRN163L inhibited the in vitro clonogenic growth of CD138neg MM CSC isolated from the bone marrow aspirates of patients with MM. These data demonstrate that TA is detectable within both immature MM CSC and mature MM plasma cells, and that CSC from both cell lines and primary clinical samples are targeted by the telomerase inhibitor GRN163L. Therefore, this agent may offer a novel therapeutic approach to myeloma as well as other diseases in which CSC have been identified.
Rbm15 Affects Notch Signaling and Myelopoiesis.
Authors: Renda Matthew J. , Cheng Ee-Chun , Wang Lin , Ma Xian-Young , Krause Diane S. 
Published: October 2019

Abstract
Acute Megakaryoblastic Leukemia (AMKL) presents with one of two different genotypic abnormalities; either Down Syndrome (DS) accompanied with GATA-1 mutations, or a non-DS translocation t(1;22)(p13;q13). In AMKL associated with DS, there is trisomy 21 and various partial loss of function mutations in GATA-1. In non-DS AMKL, the translocation t(1;22)(p13;q13) encodes a fusion protein, RBM15-MKL, comprised of the transcriptional co-factors RBM15 (chromosome 1) and MKL (chromosome 22). In order to elucidate the role of the RBM15-MKL fusion protein in AMKL, we must understand the normal functions of RBM15 and MKL. Herein we demonstrate a role for Rbm15 in myeloid differentiation.
Previous work in the lab showed that Rbm15 is expressed at highest levels in hematopoietic stem cells, and at more moderate levels during myelopoiesis of murine cell lines and primary murine cells. Therefore, we hypothesized that Rbm15 plays a role in myeloid differentiation. Indeed, we demonstrate that shRNA-mediated knockdown of Rbm15 enhanced the differentiation of 32DWT18 myeloid precursor cells. Recent studies have shown the Rbm15 homolog, Sharp, interacts with RBPJk, a critical transcription factor in the Notch signaling pathway; and since Notch signaling is essential for hematopoiesis, we hypothesized that Rbm15 may also modulate Notch signaling. We demonstrate that Rbm15 alters Notch-induced HES1 promoter activity in a cell-type specific manner. Rbm15 inhibits Notch-induced HES1 activity in non-hematopoietic cell lines, but stimulates this activity in hematopoietic cell lines including 32DWT18 and HEL (human erythroleukemia). In addition, we show that the N-terminus of Rbm15 co-immunoprecipitates with RBPJk and has a dominant negative effect by impairing the activation ability of HES1 promoter activity by full length-Rbm15.
Thus, Rbm15 is differentially expressed during hematopoiesis and may act to inhibit myeloid differentiation in hematopoietic cells via a mechanism that is mediated, at least in part, by stimulation of Notch signaling via interaction with RBPJk. Consistent with a potential mechanistic role of Rbm15 and Notch in myelopoiesis, we have shown that shRNA-mediated knockdown of Rbm15 in 32DWT18 cells promotes myeloid differentiation, suggesting that the RBM15 component of the RBM15-MKL fusion protein may act by blocking differentiation. Currently, we are examining the effect of RBM15 overexpression and knockdown in primary mouse bone marrow cells using in vitro and in vivo assays.
The Hypomorphic Gata1low Mutation Alters the Proliferation/Differentiation Potential of the Common Megakaryocytic-Erythroid Progenitor.
Authors: Ghinassi Barbara , Sanchez Massimo , Martelli Fabrizio , Amabile Giovanni , Vannucchi Alessandro M. , Migliaccio Giovanni , Orkin Stuart H. , Migliaccio Anna Rita 
Published: October 2019

Abstract
Recent evidence suggests that mutations in the Gata1 gene may alter the proliferation/differentiation potential of hemopoietic progenitors. We had previously described that hematopoietic tissues from mice carrying the hypomorphic Gata1low mutation contain high numbers (~10%) of “unique” progenitor cells that generate colonies composed by erythroblasts, megakaryocytes and mast cells (Migliaccio et al, J Exp Med197:281, 2003). Predicted by the stochastic model of hematopoietic commitment, such a tri-lineage progenitor cell has not been isolated prospectively as yet from the marrow of normal mice. The aim of this study was to clarify the role of Gata1 in hematopoietic commitment by identifying the antigenic profile and proliferation potential of the Gata1low progenitors giving rise to tri-lineage colonies. First, we compared the frequency of granulo-monocytic (GMP), megakaryocytic-erythroid (MEP), common myeloid (CMP) and mast-cell restricted (MCP) progenitors in marrow, and spleen, from wild-type and Gata1low littermates. Next, the different populations were isolated, and their differentiation and proliferation potential characterized under conditions of limiting dilution followed by single cell re-cloning. In Gata1low mice, the frequency of cells with the antigenic profile of CMP, MEP, and GMP was normal in marrow and markedly increased in spleen, while cells with the MCP profile were not detectable. However, mutant cells isolated according to the MEP phenotype, had the “unique” property to generate mast cells and their precursors in 7 days of culture, in addition to erythroblasts and megakaryocytes. Furthermore, the progeny of ~11% of mutant MEP could be propagated in culture, as single cells, with 95% efficiency, for up of 4 months. In comparison, the progeny of wild-type MEP became extinguished in 7–14 days. In agreement with these results, tri-lineage (erythroid, megakaryocytic and mastocytic) cell lines were consistently isolated from bone marrow and spleen cells of Gata1low mice. These results indicate that cells with the phenotype corresponding to myeloid, but not those corresponding to mastocytic, progenitors are detectable in tissues from Gata1low mice. However, in these mice, the mast cell generating activity is abnormally acquired by MEP, that, therefore, are similar in phenotype, but not in function, to wild-type MEP. These results confirm the crucial role played by Gata1 in hematopoietic commitment and identify, as a new target for the Gata1 action, the restriction point at which CMP became either MEP or MCP.
Electroporation of CXCR4 mRNA into Primary Mesenchymal Stem Cells Enables SDF-1 Dependent Migration.
Authors: Ryser Martin F. , Ugarte Fernando , Thieme Sebastian , Gentsch Marcus , Herber Martin , Brenner Sebastian 
Published: October 2019

Abstract
mRNA transfection is a safe alternative to DNA transfection for transient transgene overexpression in mammalian cells as genomic integration of the transferred nucleic acid is impossible. We developed a new mRNA electroporation protocol for transfection of primary mesenchymal stem cells (MSCs) using a hypoosmolar buffer system. Polyadenylated and capped mRNA was in vitro transcribed from DNA templates by T7 RNA polymerase. The DNA template generation has been simplified by our group using PCR amplification of the transgene sequence with primers providing the T7 RNA polymerase promoter and optimized 5′ and 3′ UTR sequences for better translation and RNA stability. This manoever allows to generate the DNA template from any plasmid vector and bypasses the need for additonal cloning steps. Canine primary MSCs were isolated by selection of adherent cells from bone marrow aspirates in a low glucose medium. Transfection of GFP or CXCR4 mRNA into primary MSCs resulted in transgene overexpression in more than 90% of target cells with excellent viabilities (>95%). Expression of CXCR4 was well detectable for up to 96 hours after transfection. SDF-1 dependent Ca-flux was only present in CXCR4-transgene overexpressing MSCs suggesting functional expression of the chemokine receptor. Transwell migration experiments demonstrated a 2 fold increased migration of CXCR4 mRNA transfected MSCs towards a gradient of SDF-1 compared to background migration without SDF-1. GFP mRNA transfection did not result in any SDF-1 stimulated migration. Our data demonstrate efficient and safe transient genetic engineering of primary MSCs based on mRNA transfection. mRNA transfection induced chemotaxis will facilitate receptor mediated targeting of transplanted MSCs at specific body compartments.
A Novel Peptide Containing a Nine Amino Acid Sequence from Nur77 Induces Bcl-2-Dependent Apoptosis in AML.
Authors: Andreeff Michael , Konopleva Marina , Watt Julie C. , Samudio Ismael J. , Satterthwait Arnold C. , Kitada Shinichi , Zhang Xiao-kun , Reed John C. 
Published: October 2019

Abstract
Nur77 (also known as TR3 and NGFI-B) is a nuclear orphan receptor that in response to various stimuli can translocate from the nucleus to the mitochondria, bind Bcl-2, and induce a conformational change in Bcl-2 that exposes its BH3 domain. This conformational change of Bcl-2 transforms this protein into a pro-apoptotic molecule that can induce cytochrome c release and apoptosis (Cell 116:527, 2004). Interestingly, in acute myeloid leukemia (AML) cell lines and blasts, Nur77 is absent. We have recently generated a nine amino acid peptide from the Nur77 protein (TR3) that is capable of inducing the same pro-apoptotic conformational change in Bcl-2 that Nur77 elicits (manuscript submitted). We tested the hypothesis that a cell-permeable version of this peptide can induce Bcl-2-dependent apoptosis in AML cells and AML stem cells. Primary AML samples (n=6) were incubated with 20 μM control or TR3 peptide for 24 hrs. Induction of apoptosis was measured as CD34+38−123+ PS/Annexin V+ by multiparametric flow cytometry. Our results demonstrate that the L-enantiomer form of TR3 indeed induces apoptosis in total AML cells (60%, p=0.001) and CD34+38−123+ stem cells (67%, p=0.001), as compared to control peptide. Bax expression did not affect the peptide’s ability to induce apoptosis, as wild-type HCT116 cells and HCT116 cells deficient in Bax showed similar levels of apoptosis after treatment with the TR3 peptide. However, Bcl-2 expression was shown to be critical since lentiviral shRNA ablation of Bcl-2 in KG1 cells completely prevented induction of apoptosis by TR3 peptides. We conclude that the TR3 peptide is a potent inducer of apoptosis that mimics the action of Nur77 on Bcl-2 at the mitochondrial level. These results suggest that the Nur77 peptide or compounds that mimic this peptide may have utility as a novel therapeutic agent against Bcl-2 expressing cancers and leukemias.