bluuebunny/crossref_metadata_2025_split huggingface dataset:
Triterpenoids Display Single Agent Activity in a Mouse Model of CLL/SBL.
Authors: Kress Christina L. , Konopleva Marina , Krajewska Maryla , Martinez-Garcia Vanesa , Lefebvre Sophie , Hyer Marc L. , McQueen Teresa , Andreeff Michael , Reed John C. , Zapata Juan 
Published: October 2019

Abstract
The synthetic triterpenoid 2-Cyano-3,12-Dioxooleana-1,9-Dien-28-Oic Acid (CDDO) induces apoptosis of leukemia cells through a novel mechanism and has recently entered Phase I human clinical trials. We studied the effects of CDDO and its imidazolide derivative (CDDO-Im) on cultured human chronic lymphocytic leukemia (CLL) cells and on B cells from TRAF2DN/Bcl-2 transgenic mice, a new mouse model of CLL and small B cell lymphoma (SBL). Both triterpenoids efficiently induced death of malignant human and mouse B-cells ex vivo, although CDDO-Im was over 10-fold more potent than CDDO. Treating TRAF2DN/Bcl-2 mice that had developed leukemia with liposome-formulated CDDO or CDDO-Im resulted in significant reductions of B cells in blood, spleen and lung, with CDDO-Im more potent than CDDO, while treatment with empty liposomes had no impact on disease. Analysis of blood cells recovered from treated mice showed that CDDO-Im is a potent inducer of cell dead in vivo. Furthermore, CDDO-Im efficiently eradicated mouse CLL cells but had a lesser effect on the viability of normal B cells. These results demonstrate that triterpenoids CDDO and CDDO-Im reduce leukemia and lymphoma burden in vivo in a transgenic mouse model of CLL/SBL and suggest that CDDO-based synthetic triterpenoids should be tested for clinical activity in patients with CLL. Our results also provide evidence of the suitability of our mouse model of CLL/SBL as a preclinical platform for chemotherapeutic drug testing.
FLT3-ITD Mediated Growth Advantage of Human CD34+ PBPCs Is Dependent on Stromal Cells.
Authors: Jacobi Angela , Ryser Martin F. , Koch Sina , Brenner Sebastian 
Published: October 2019

Abstract
Activating mutations of the FLT3-receptor tyrosine kinase such as the short internal tandem duplication (ITD) represent the single most common genetic aberration in patients with acute myeloid leukemia (AML). FLT3-ITD mutations are present in about 25% of AML patients and are associated with high blast counts and a higher rate of relapse after conventional chemotherapy. In search for a valid model system for FLT3-ITD AML we greatly improved retroviral gene transfer of the mutated FLT3 receptor into human G-CSF mobilized CD34+ peripheral blood progenitor cells (PBPCs). In the past, retroviral vector production for FLT3 had been hampered by low virus titers related to transgene toxicity in the virus producing cells. Virus vector production in the presence of the FLT3 inhibitor GTP14562 strongly increased the virus vector titer. Subsequent ultracentrifugation and resuspension of the concentrated virus vector in fresh medium enabled us to consistently transduce CD34+ PBSCs to levels of greater than 50%. For individually tested CD34+ PBPC from 5 donors, co-cultivation of FLT3-ITD overexpressing PBPC on the irradiated mouse stromal cell line M210-B4 resulted in a 6 fold increased formation of early cobble stones and a dramatic proliferation advantage for suspended cells compared to naïve, GFP-transduced or FLT3-wildtype transduced PBPCs. The enhanced proliferation of the FLT3-ITD transduced cells was associated with decreased CD34 expression compared to control-transduced cells. Addition of the CXCR4 chemokine inhibitor AMD3100 to the co-culture decreased the cobble stone formation and growth advantage of FLT3-ITD transduced PBPCs. In contrast, cultivating the same FLT3-ITD overexpressing PBPCs in liquid culture (X-VIVO10, 1%HSA, TPO, SCF, FLT3 and IL-3) resulted in a moderate or no growth advantage or in an even reduced cell viability (dependent on the donor PBPCs used), which indirectly highlights the influence of stromal cells on FLT3-ITD overexpressing PBPCs. And in contrast to previously published data from murine cells, addition of the CXCR4 ligand stromal cell derived factor-1 (SDF-1) to liquid cultures did not confer an additional growth advantage for FLT3-ITD positive cells. Using an improved transduction protocol we demonstrate that the robust FLT3-ITD mediated growth advantage for human PBPCs is dependent on co-cultivation on a stromal cell layer and we show that the enhanced proliferation can be partly inhibited by the CXCR4 inhibitor AMD3100. Studies to delineate factors that confer FLT3-ITD specific cell growth on stromal cells are under way.
Prospective Isolation of Mesenchymal Stem Cells from Human Bone Marrow and Placenta Using a Frizzled-9-Specific Monoclonal Antibody.
Authors: Battula Venkata L. , Treml Sabrina , Kanz Lothar , Buhring Hans-Jorg 
Published: October 2019

Abstract
We have recently shown that Frizzled-9 (FZD9) is expressed on the cell surface of multipotential mesenchymal stromal cells derived from human bone marrow (BM) and placenta (PL). To test whether FZD9 is also expressed on primary mesenchymal stem cells (MSC) with CFU-F (colony forming unit fibroblast) capacity, we used the FZD9-specific monoclonal antibody W3C4E11 to fractionate BM and PL cells into FZD9+ and FZD9- populations. Defined numbers of sorted cells were then cultured in a serum free bFGF-containing medium, originally designed fur the culture of human ES cells. 14 days after culture, the resulting fibroblastoid cells were stained with Giemsa staining solution and colonies consisting of > 50 cells were enumerated. In the FZD9+ fraction, a 70 fold increase of the CFU-F frequency in PL and a 80–90 fold increase in BM was observed. Cultured FZD9+ cells also expressed the stem cell markers Oct-4, nanog-3, and nestin, as well as SSEA-4, TRA1-2-49/6E, CD105, CD13, CD164, CD318, and W8B2B10 antigen. After culture under appropriate conditions, FZD9+ cells could be differentiated into cells of the ectodermal (neuronal like cells), endodermal (pancreatic like cells), and mesodermal (adipocytes and osteoblasts) lineages, indicating the multi-lineage differentiation capacity of these cells. In conclusion, FZD9 is a novel marker for the prospective isolation of MSC from human BM and PL.
Prospective Identification and Characterization of Human Mesenchymal Stem Cell Subpopulations.
Authors: Tormin Ariane , Brune Jan C. , Borg Åke , Neumann Ulf , Olofsson Tor , Lauster Roland , Jakobsen Sten-Eirik , Scheding Stefan 
Published: October 2019

Abstract
Mesenchymal stem cells (MSC) are multipotent cells that readily differentiate into a variety of cell types including osteoblasts, chondrocytes, and adipocytes. They support hematopoiesis (stroma function) and have potent immunomodulatory properties making them promising candidates for clinical use. Although MSC cultures are heterogeneous in morphology, no specific markers are available that would allow for the prospective isolation of distinct subpopulations. Therefore we investigated whether potential MSC subpopulation markers could be identified by gene expression profiling of MSC that were sorted based on functional parameters (i.e. proliferation characteristics). Human MSC were generated in standard cultures and stained with carboxyfluoresceine-succinimidylesther (CFSE) for cell division tracking. FACS analysis of CFSE-stained cells after 10 days culture showed that the majority of cells had undergone more than 3 cell divisions (51.2 ± 1.7%) whereas only 3.5 ± 0.9 % had not divided. Based on these results MSC were sorted by FACS according to their divisional history into non-proliferating cells (NP-MSC) and rapidly-proliferating cells (RP-MSC). Interestingly, the CFU-F frequencies of the NP-MSC were considerably (5-times) lower compared to RP-MSC. Furthermore, RP-MSC with low forward-/side-scatter properties had a higher CFU-F frequency than those with high scatter properties. Comparative oligonucleotide microarray analysis of FACS-sorted NP-MSC and RP-MSC populations identified a total of 112 differentially (≥4-fold) expressed genes. Fifty genes were significantly higher expressed in RP-MSC with 12 of them being cell cycle associated. Sixty-two genes showed a higher expression in NP-MSC and more than 20 of them were related to adhesion molecules, extracellular matrix proteins or cell senescence. Two of the differentially expressed genes (VCAM-1, FMOD) that corresponded to cell surface molecules were further tested for their potential to prospectively identify MSC subpopulations. Remarkably, FACS analysis using anti-VCAM-1 (CD106) and anti-fibromodulin (fmod) antibodies showed that approximately 40% and 3% of MSC were CD106neg/fmodneg and CD106pos/fmodpos, respectively. MSC were then sorted by FACS according to their expression of these markers and assayed for CFU-F frequency. Significant differences in CFU-F frequencies were observed between the double-negative and the double-positive MSC (12.3 ± 2.8 and 4.7 ± 2.1 colonies per 100 cells for CD106neg/fmodneg and CD106pos/fmodpos MSC, respectively). Experiments to test for differentiation potential differences are ongoing. Taken together, the data clearly demonstrate functional differences between MSC subpopulations. Furthermore, cell sorting based on proliferation characteristics and gene expression profiling enabled to identify surface markers that allowed for the first time to prospectively identify MSC subpopulations.
Novel Small Molecule MDM2 Inhibitor MI-63 Induces p53-Dependent Apoptosis in AML Cell Lines.
Authors: Samudio Ismael , Dietrich Martin , Corn Paul , Yang Dajun , Borthakur Gautam 
Published: October 2019

Abstract
Although TP53 mutations are rare in acute myeloid leukemia (AML), inactivation of wild-type p53 protein frequently occurs through overexpression of its negative regulator MDM2 (murine double minute 2). We investigated the effects of MI-63, a small molecule that activates p53 by inhibition of MDM2-p53 interaction [ Ki value of 3 nM (J Med Chem.2006;49(12):3432–5)] in AML cell lines. Treatment with MI-63 triggered apoptosis (evidenced by loss of membrane potential and externalization of phosphatidylserine) in AML cell lines with wild-type p53 (OCI-AML-3 and MOLM13) in a time and concentration-dependent manner (IC50 at 72 hrs.= 2.5 μM for OCI-AML-3 and 1 μM for MOLM-13), while a p53-null AML cell line (HL-60) was resistant (IC50 not reached at 10 μM). Moreover, knockdown of p53 in OCI-AML3 cells rendered this cell line resistant to MI-63 induced apoptosis while control vector infected OCI-AML-3 cells remained as sensitive to MI-63 similar to the parental cells.
Mechanistic studies showed that MI-63 blocks G1/S phase transition in AML cells with wild-type p53 resulting in accumulation of cells in G1 phase (percentage cells inG1 phase at 24 hrs. = 88.66% vs 43.49% in cultures with DMSO control) while MI-61, a skeletally related but inactive control compound failed to do so (41.63%). Treatment with MI-63 increased cellular levels of p53 and p53 dependent proteins in OCI-AML-3 cells that include p21 and BH3-only pro-apoptotic protein Puma and pro-apoptotic multi-domain Bcl-2 family member Bax. Additionally, MI-63 induced a profound decrease in the levels of MDM4, an MDM2 homolog that has been reported to mediate resistance to the effects of nutlin-3a, suggesting that MI-63 may offer a therapeutic advantage in cells expressing high levels of MDM4.
Finally, supporting the concept that increased levels of p53 modulate the apoptotic rheostat both directly, by behaving as a BH3-only protein, and indirectly by increasing the levels of sensitizer BH3-only proteins, MI-63 potently synergized with AT-101, an orally available pan inhibitor of Bcl-2, Bcl-xL and Mcl-1 (currently being evaluated as an antitumor agent in Phase I/II trials by Ascenta Therapeutics), to induce mitochondrial dysfunction and apoptosis in OCI-AML-3 cells (average combination index = 0.055±0.019).
Taken together our results support preclinical evaluation of novel small molecule MI-63 alone and in combination with Bcl-2 inhibitors for the therapy of AML. The studies in primary AML samples are ongoing.
Fig.1: MI-63 Induced Apoptosis Requires Intact p53 Fig.1:. MI-63 Induced Apoptosis Requires Intact p53 Fig.2: Efect of MI-63 on p53 and Related Proteins (comparison with N3a, a known MDM2 inhibitor included) Fig.2:. Efect of MI-63 on p53 and Related Proteins (comparison with N3a, a known MDM2 inhibitor included)
Serotonin Receptor Antagonists Have an In Vitro and In Vivo Anti-Myeloma Effect That Is Mainly Mediated by Caspase Dependent Apoptosis.
Authors: Ocio Enrique M. , Hideshima Teru , Yasui Hiroshi , Tanyel Kiziltepe , Ikeda Hirosi , Okawa Yutaka , Vallet Sonia , Jin Janice , Ishitsuka Kenji , Raje Noopur , Catley Laurence , Anderson Kenneth C. 
Published: October 2019

Abstract
To date, serotonin (5-hydroxytryptamine: 5-HT) has been associated with the regulation of several central nervous system functions such as mood, temperature, memory, sleep or appetite. Importantly, a proliferative effect of 5-HT in both normal and tumoral tissue has recently been described. Therefore, serotonin-receptor antagonists have been tested for antineoplastic purposes. In this study, we have investigated the in vitro and in vivo anti-multiple myeloma (MM) effect of two analogs of 5-HT-receptor antagonists (ICI-735 and ICI-685). Both compounds induced cytotoxicity (MTT) and a decrease in proliferation (thymidine uptake) in several MM cell lines both sensitive and resistant to conventional therapies, as well as freshly isolated MM cells, with an IC-50 at 24h ranging between 3-10 μM for ICI-735 and 5–20 μM for ICI-685. No significant toxicity was observed at these doses of both drugs in PBMCs obtained from normal donors. In order to analyze the efficacy of the drugs in the presence of the bone marrow (BM) microenvironment, we tested both compounds in MM1S cells co-cultured with IL-6, IGF-1 or long-term patient BM stromal cells (SCs). ICI-735 and ICI-685 overcame the proliferative advantage conferred by the cytokines and BMSCs. Apoptosis was the main mechanism of cytotoxicity, assessed by Annexin-V staining. Treatment with ICI-735 and ICI-685 induced cleavage of PARP and caspase 3, 7, 8 and 9 at early time points, suggesting involvement of both extrinsic and intrinsic pathways of apoptosis. The presence of caspase-induced apoptosis was confirmed since a pan-caspase inhibitor (ZVAD-FMK) partially abrogated apoptosis, as well as the cleavage of PARP and caspases, induced by these compounds. An increase of AIF was also detected in the cytoplasmic fraction of cells treated with ICI-735, indicating a role for caspase-independent apoptosis. The in vivo efficacy was next evaluated in a xenograft murine (CB-17 SCID-mice) model. Five mice were injected intraperitoneally with 20 mg/Kg of ICI-735, while 5 received vehicle alone. No significant toxicity was detected, except for a slight somnolence after the first doses, in the mice that received the drug. A decrease in tumor volume was observed in the treated group and, despite the small number of mice, survival analysis showed a trend toward prolonged survival for mice receiving the drug (p=0.11). Ongoing studies are providing the preclinical rationale for clinical protocols to improve patient outcome in MM.
Identification of Off-Patent Drugs That Reverse Daunorubicin Efflux Mediated by ABCB1 in T-ALL Cells.
Authors: Winter Stuart S. , Lovato Debbie M. , Khawaja Hadya M. , Edwards Bruce S. , Steele Irena D. , Young Susan M. , Oprea Tudor I. , Sklar Larry A. , Larson Richard S. 
Published: October 2019

Abstract
In acute leukemias, the overexpression of P-glycoprotein, encoded by the ATP Binding Cassette B1 (ABCB1) gene contributes to multidrug resistance (MDR), and is considered one of the major obstacles to successful cancer chemotherapy. The identification of small molecules that reverse ABCB1 efflux activity is critical for the successful treatment of cancers, including relapsed T-lineage acute lymphoblastic leukemia (T-ALL). However, the dose-limiting toxicities of many MDR reversal agents have restricted their use in clinical trials, and more effective and clinically applicable reversal agents remain to be identified. We have recently developed a T-ALL cell line that overexpresses ABCB1 and exhibits multiple drug resistance (MDR) to daunorubicin, prednisolone, and vincristine, but not L-asparaginase. The MDR can be reversed by suppression of ABCB1 expresssion with siRNA or 5 μM cyclosporine (CSA). Using this cell line, we developed a flow cytometry based, high-throughput screening assay that quantifies ABCB1 efflux using the fluorescent probe JC-1 (Swerts, et al Leuk Lymphoma 45:2221–8, 2004). We screened a library of 880 off-patent drugs for their ability to inhibit ABCB1 efflux at concentrations of 4 μM, and 19 compounds were identified, including CSA. Based on a published record of safe internal use in humans, 12 compounds were retained for further analysis (3 compounds were originally described as calcium channel blockers, 1 as sodium channel blocker, 1 as ACE inhibitor, 1 as dopamine uptake inhibitor, 1 as Topoisomerase II inhibitor, 2 as steroids, 2 as antifungal and 1 as immunosuppressant). We determined the 50% inhibitory concentration (IC50) of drug for ABCB1 efflux, the efflux reversal concentration of drug that rescued DNR-induced T-ALL cell death (ECrev50), and the corresponding in vitro toxic dose in 50% of treated T-ALL cells (TD50). Due to space limitations, detailed data could not be presented in the abstract. To our knowledge, 8 of the 12 compounds have not been previously described as ABCB1 inhibitors. These compounds may be useful as chemosensitizers or as lead compounds for development of improved ABCB1 inhibitors in T-ALL as well as other cancers.
Decitabine Induces High Response Rates in Patients with Chronic Myelomonocytic Leukemia (CMML).
Authors: Jabbour Elias , O’Brien Susan , Ravandi-Kashani Farhad , Cortes Jorge , Borthakur Gautam , Verstovsek Srdan , Garcia-Manero Guillermo , Giles Francis , Zanoria Lourdes , Davisson Jan , Issa Jean-Pierre , Kantarjian Hagop M. 
Published: October 2019

Abstract
Background The hypomethylating agents decitabine and azacitidine have significant anti-myelodysplastic (MDS)activity and have been FDA approved for the treatment of MDS and CMML. Experience in CMML has been minimal.
Study Aims Evaluate the efficacy of decitabine in CMML.
Study Group and Treatment Patients with CMML received decitabine 20 mg/m2 IV/1 hour daily x 5 or 2 alternative schedules, delivering 100 mg/m2/course every four weeks (Kantarjian, Blood 2006). Response was evaluated by the modified IWG criteria (Cheson, Blood 2006).
Results Nineteen patients were treated. Their median age was 66 years (range 44–82 years). Splenomegaly was present in 4 (21%); hemoglobin less than 10 g/dL in 10 (53%); thrombocytopenia less than 100 x 109/L in 12 (63%); WBC more than 40 x 109/L in 5 (26%); chromosomal abnormalities in 6 (32%); prior therapy for CMML in 9 (47%); marrow or peripheral blast 5% or more in 11 (58%). Overall, 13 patients (69%) achieved IWG responses: CR in 11 (58%), other HI in 2 (11%). Improvement of thrombocytopenia was noted in 7/8 patients (88%) with pretreatment platelets less than 50 x 109/L. Median survival was 19 months. Among 6 patients with pretreatment chromosomal abnormalities who achieved response, 1 (17%) had disappearance, and 2 had > 50% reduction of cytogenetic abnormalities. Extramedullary toxicities were minimal.
Conclusions Decitabine is active and safe in CMML. Future studies may combine decitabine with histone deacetylase inhibitors, chemotherapy (eg cytarabine, topotecan), or growth factors.
Expression of Proliferation Related Genes in Myelodysplastic Syndromes (MDS) and Secondary Acute Myeloid Leukemia (AML) Patients with Resistance to Low Dose Vidaza and Thalidomide.
Authors: Galili Naomi , Ebert Benjamin L. , Westervelt Peter , Wasserman Jessica , Lee Daniel , Raza Fatima Z. , Golub Todd R. , Raza Azra 
Published: October 2019

Abstract
Vidaza and Thalidomide were administered to 29 patients with MDS or AML. Vidaza was given at a dose of 75mg/kg subq X 5 days q28 days and Thalidomide starting at 50mg/day and increasing to 100mg. Therapy was well tolerated. Median age was 70 years, and there were 16 males. Two patients had RA, 2 RARS, 9 RAEB, 4 CMMoL, 10 AML and 2 Unknowns. According to IPSS, 1 had low, 7 had Int-1, 5 had Int-2 and 4 had high risk disease, and 2 unclassified and 10 had AML. Eleven patients had normal, 14 abnormal and 4 unknown cytogenetics. Hematologic improvement (HI) was seen in 14 and stable disease in 6 while 5 had disease progression. cDNA from pre-therapy BM mononuclear cells of 28/29 patients was hybridized to Affymetrix HG-U133AA microarrays and data was analyzed using the GenePattern software package. Marker genes were selected using ClassNeighbors algorithm with the signal-to-noise metric. When comparing resistant disease (RD) patients with HI (6) and others (2), of the 40 top marker genes over-expressed in the RD group, 21 are directly associated with cellular proliferation and can be divided into 3 groups. Group I (cell cycle) consisted of 9 genes; BUB1B, CCNA2, TMPO, CDC2, CCNB1, UBE2C, TTK, CDC20 and MCM5. Group II (replication repair) had 5 genes; TOP2A, RRM2, RFC3, FEN1, RNAH2A. Group III (spindle/chromosome structure) had 7; KIF2C, NUSAP1, CENPF, MK167, SPAG5, CENPA and STK6. Over-expression of these genes would indicate rapid cellular proliferation which may be an underlying cause of drug resistance. These results are especially striking since the treatment regimen consisted of a combination of two drugs, Vidaza and thalidomide, which purportedly act through different mechanisms. We conclude that the RD patients share a molecular signature which is also consistent with a demonstrated mechanism of cell cycle resistance, and underscores the future clinical usefulness of this methodology.