bluuebunny/crossref_metadata_2025_split huggingface dataset:
P38 MAPK Inhibition Enhances PS-341 (bortezomib)-Induced Cytotoxicity Against Multiple Myeloma Cells.
Authors: Hideshima Teru , Podar Klaus , Chauhan Dharminder , Ishitsuka Kenji , Mitsiades Constantine , Tai Yu-Tzu , Hamasaki Makoto , Raje Noopur , Hideshima Hiromasa , Schreiner George , Nguyen Aaron , Navas Tony , Munshi Nikhil C. , Richardson Paul G. , Higgins Linda S. , Anderson Kenneth C. 
Published: October 2019

Abstract
PS-341 (pyrazylcarbonyl-Phe-Leu-boronate, bortezomib, Velcade™) represents a class of peptide boronate proteasome inhibitors which inhibit 26S proteasome activity, and demonstrated promise as potential novel anti-cancer therapies. PS-341: induces heat shock proteins (Hsps); activates JNK; induces apoptosis in MM cells mediated by activation of caspase-8, -9, and -3; induces cleavage of DNA protein kinase catalytic subunit (DNA-PKcs) and ATM; overcomes conventional drug resistance conferred by IL-6 or adherence to bone marrow stromal cells (BMSCs); and further abrogates IL-6-triggered signaling cascades by caspase-dependent downregulation of gp130 (CD130). Importantly, a phase II clinical trial of Velcade in refractory relapsed MM demonstrated 35% responses, including 10% complete and near complete responses; however, 65% of patients did not respond to PS-341. We have previously shown that heat shock protein (Hsp)27 is upregulated after PS-341 treatment, that overexpression of Hsp27 confers PS-341 resistance, and that inhibition of Hsp27 overcomes PS-341 resistance. Since Hsp27 is a downstream target of p38 mitogen-activated protein kinase (MAPK)/ MAPK-mitogen-activated protein kinase-2 (MAPKAPK2), we hypothesized that inhibition of p38 MAPK activity could augment PS-341 cytotoxicity by downregulating Hsp27. Although p38 MAPK inhibitor SCIO-469 (Scios Inc, CA) alone did not induce significant growth inhibition in MM.1S cells, it blocked baseline and PS-341-triggered phosphorylation of p38 MAPK, as well as upregulation of Hsp27, associated with enhanced cytotoxicity. Importantly, SCIO-469 enhanced phosphorylation of c-Jun NH2-terminal kinase (JNK) and augmented cleavage of caspase-8 and poly (ADP)-ribose polymerase (PARP). Moreover, SCIO-469 downregulated PS-341-induced increases in G2/M phase cells, associated with downregulation of p21Cip1 expression. These results were further confirmed using transient transfection with p38 MAPK siRNA. Importantly, SCIO-469 treatment augmented cytotoxicity of PS-341 even against PS-341 resistant cell lines and patient MM cells. These studies therefore provide the framework for clinical trials of SCIO-469 to enhance sensitivity and overcome resistance to PS-341, thereby improving patient outcome in MM.
Two Novel Activating Germline Mutations of the C-RAF Proto-Oncogene Predisposing to Solid Tumors and Therapy-Related Acute Myeloid Leukemia.
Authors: Zebisch Armin , Staber Philipp B. , Fischereder Katja , Bodner Claudia , Hiden Karin , Linkesch Werner , Auner Holger W. , Emberger Werner , Windpassinger Christian , Schimek Michael G. , Hoefler Gerald , Troppmair Jakob , Sill Heinz 
Published: October 2019

Abstract
Constitutive activation of the RAS-RAF-MEK-ERK signaling cascade plays an important role in the pathogenesis of AML. We were interested whether abnormalities of the serine-threonine kinases A -, B, - and C -RAF occur in AML and whether they might be causative for activation of this pathway. Expression of these genes was assessed by real-time quantitative (rtq) PCR in 102 patient samples of AML, three AML cell lines and normal CD34+ cells of seven individuals. Results were correlated with the phosphorylation status of ERK 1/2, as measured by immunoblot analysis. 45/82 (54,9%) of AML cases showed ERK phosphorylation indicating constitutive activation of the pathway. However, there was no correlation with expression levels of either A-, B- or C-RAF. Deletions of the B-RAF gene as revealed by rtq PCR were observed in 20/99 (20%) of AML cases and were consistent with cytogenetic results but did not correlate with ERK activity, either. In addition, we screened for mutations of B- and C-RAF in all samples showing ERK phosphorylation using PCR and sequence analysis. Two novel C-RAF missense mutations, both of them located in the kinase domain, were detected in the subgroup of therapy related AML (t-AML): S427G in one and I448V in another patient. Expression of the mutated proteins in mammalian cells resulted in the constitutive activation of MEK and ERK, thus strongly suggesting that the mutations activated C-RAF. Sequence analysis of the primary tumors (colon cancer and teratoma, respectively) as well as buccal epithelial cells revealed these mutations of germline origin and denaturing high pressure liquid chromatography revealed a frequency of <1/400 alleles in the healthy population. Immunohistochemistry using antibodies against phosphorylated ERK demonstrated the pathway to be constitutively activated in the primary tumors as well but inactive in non-neoplastic tissue. In conclusion, we have identified the first activating missense mutations of the C-RAF proto-oncogene in a human tumor. Since both are of germline origin and the primary as well as secondary malignancies showed constitutive activation of the RAS-RAF-MEK-ERK pathway, these mutations might be regarded as predisposing factors in these individuals.
Identification of Cooperating Genetic Alterations in RUNX Leukemia Using the Mouse Model for the Human Familial Leukemia, FPD/AML.
Authors: Osato Motomi , Yamashita Namiko , Yanagida Masatoshi , Huang Liqun , Kogan Scott , Iwasaki Masayuki , Nakamura Takuro , Shigesada Katsuya , Asou Norio , Ito Yoshiaki 
Published: October 2019

Abstract
The RUNX1/AML1 gene is essential for hematopoiesis and is most frequently involved in human leukemias. Loss-of-function of RUNX1 is the common underlying mechanism of RUNX leukemias: those carrying t(8;21), inv(16) and RUNX1 point mutations. As the weakest mode, haploinsufficiency of RUNX1/AML1 causes familial platelet disorder with predisposition to acute myeloid leukemia (FPD/AML). Mice heterozygous for Runx1 null mutation, Runx1+/−, appear genetically equivalent to human FPD/AML patients, but showed no apparent defects and did not develop spontaneous leukemia, implying that additional genetic alterations are required for leukemia. To identify such abnormalities, retroviral insertional mutagenesis was employed by using BXH2 mice that have spontaneously transmittable ecotropic retrovirus. BXH2-Runx1+/− mice showed a shorter disease latency and more myeloid-specific phenotype than wild-type littermates. Therefore, BXH2-Runx1+/− mice appear to serve as the mouse model for FPD/AML to investigate myeloid leukemia. The genes selectively affected in BXH2-Runx1+/− mice by retroviral integration are likely to cooperate with Runx1+/−. c-Kit locus was involved twice in 24 BXH2-Runx1+/− but neither in 17 wild-type littermates nor in 135 inbred BXH2 mice reported in the RTCGD database, suggesting that c-KIT mutation cooperates with RUNX alteration in human leukemia. In fact, constitutively active mutants of c-KIT or functionally equivalent FLT3, were found in 10 out of 25 (40%) of human RUNX leukemias. Together, BXH2-Runx1+/− system appears useful to identify the genes cooperating with RUNX1 abnormalities.
Sensitization for γ-Irradiation-Induced Apoptosis by Smac.
Authors: Giagkousiklidis Stavros , Kasperczyk Hubert , Vogler Meike , Debatin Klaus-Michael , Fulda Simone 
Published: October 2019

Abstract
Smac is released from mitochondria during the onset of apoptosis and promotes apoptosis via abrogating the binding of Inhibitor of Apoptosis Proteins (IAPs) to caspases. γ-irradiation is one of the most commonly used therapeutic approaches in clinical oncology, which triggers cell death in tumors via DNA and/or membrane damage. Since we recently found that Smac agonists sensitized even resistant tumors for apoptosis induced by death receptor ligation or anticancer drugs, we investigated the effect of Smac agonists on apoptosis following γ-irradiation in the present study. Here, we report for the first time that overexpression of mitochondrial or cytosolic Smac significantly increased radiosensitivity of various cancers.
Transfection-enforced expression of Smac strongly enhanced apoptosis upon γ-irradiation in SH-EP neuroblastoma cells, which were resistant to g-irradiation in the absence of Smac. Importantly, Smac overexpression also reduced clonogenic tumor cell survival following γ-irradiation. Analysis of signaling pathways revealed that overexpression of Smac resulted in more rapid and more potent activation of caspase pathways, e.g caspase-2, -3,- 8, -9. The broad range caspase inhibitor zVAD.fmk abrogated apoptosis upon γ-irradiation indicating that apoptosis was mediated by caspases. In addition, overexpression of Smac promoted loss of mitochondrial membrane potential and cytochrome c release upon γ-irradiation. Interestingly, γ-irradiation-induced mitochondrial perturbations were blocked in the presence of the caspase inhibitor zVAD.fmk suggesting that caspase activity was required for mitochondrial alterations in response to γ-irradiation. Notably, cell cycle alterations and activation of NF-κB occured in a similar manner in vector control and Smac-transfected cells suggesting that Smac did not significantly alter the initial cellular stress response upon γ-irradiation. Importantly, Smac overexpression sensitized various tumor cell lines for γ-irradiation-induced apoptosis, indicating that the sensitization effect of Smac for γ-irradiation was not restricted to a particular cell type. By demonstrating that Smac can sensitize various tumor cells towards γ-irradiation-induced cell death, our findings provide for the first time evidence that Smac agonists may be a useful tool to enhance radiosensitivity in a variety of human cancers.
Engraftment of NOD/SCIDγcnull Mice with Multilineage Neoplastic Cells from Patients with Juvenile Myelomonocytic Leukemia.
Authors: Yamamoto Tomoko , Nakamura Yoichi , Ito Masafumi , Xu Yinyan , Yagasaki Hiroshi , Kamachi Yoshiro , Kudo Kazuko , Kojima Seiji 
Published: October 2019

Abstract
Jevenile myelomonocytic leukemia (JMML) is a rare myeloproferative disorder of early childhood, arising from pluripotent stem cells. Previous studies indicate the clonal nature of JMML, involving myeloid, erythroid, megakaryocyte and B-lymphoid lineage. However, it is unclear whether T lymphocyte lineage is involved or not. In one previous report, a patient with JMML and cytogenetic evidence of monosomy 7, a combination of fluorescence activated cell sorting and fluorescence in situ hybridization (FISH) analysis confirmed no T cell lineage involvement. One explanation of sparing T cell lymphocyte involvement in JMML is that the majority of T-lymphocytes are long-lived and borne before the occurrence of the disease. We demonstrated that cells from six patients of JMML repopurate in NOD/SCIDγcnull mice and differenciate into granulocyte, monocyte, erythroid, B-lymphocyte, T-lymphocyte and natural killer(NK) cells. The diagnosis of JMML was based on the internationally accepted criteria. 0.01 to 1×107mononuclear cells were injected through the tail vein of five week old NOD/SCIDγcnull mice. 12 week after transplantation mice were sacrificed and the cells are collected from the femoral bone and spleen and subjected to flow cytometry. The percentage of human CD45 antigen positive cells ranged from 41 to 73%. To examine the involvement of lymphocyte subpopulations, we purified human CD3+,CD19+and CD56+ cells from a murine bone marrow and spleen cells transplanted from a patient with monosomy 7. The purity of cells were more than 95%. The percentage of monosomy 7 cells determined by FISH analysis ranged from 96 to 100% in purified CD3+, CD19+and CD56+ cells. These findings support the concept that JMML originate in transplantable multilineage hematopoietic stem cells. This novel murine xenotransplant model should be useful to investigate the nature of stem cells and test new therapies for patients with JMML.
3D, a Novel Mutation That Confers Defective Sensing by Toll-Like Receptors 3, 7 and 9.
Authors: Tabeta Koichi , Du Xin , Philippe Georgel , Hoebe Kasper , Mann Navjiwan , Mudd Suzanne , Huser Nanni , Shamel Louis , Crozat Karine , Tarantino Lisa , Cooke Michael , Beutler Bruce 
Published: October 2019

Abstract
The mammalian Toll-like receptors (TLRs) comprise a key interface between cells of the host and all classes of microbial pathogen. By sensing nucleic acids, the endosomal TLRs 3, 7, and 9 play a particularly important role in the detection of viral infection, and permit the host to mount an immediate and efficacious anti-viral response. In an effort to identify novel components of the TLR signaling apparatus, we have pursued a program of germline saturation mutagenesis with N-ethyl-N-nitrosourea (ENU) in mice. The germline mutants are produced on the C57BL/6 background, and peritoneal macrophages from individual animals are screened for their competence to respond to TLR-dependent microbial inducers. A strong phenodeviant called 3d was identified in the F3 generation as a non-responder to nucleoside-based molecules such as unmethylated CpG oligodeoxynucleotides, Resiquimod (a drug of the imidazoquinoline class) and Poly I:C. TNFa production induced by TLRs 3, 7, and 9 was completely prevented in 3d homozygotes. However, heterozygotes were unaffected, and the ability to produce TNFa in response to other bacterial compounds, sensed by TLRs 1, 2, 4, and 6, was intact. 3d homozygotes show extreme susceptibility to infection by mouse cytomegalovirus (MCMV) infection in vivo. After IP inoculation with MCMV (104 PFU), 3d mutants showed impaired production of type I and type II interferons, TNF, and IL-12 in serum (p<0.001). With larger inocula (5 x 105 PFU) a splenic viral titer approximately ten-thousand fold higher than that in controls (p<0.05) and rapid mortality (p<0.0001) were observed. This novel recessive phenotype is fully penetrant on the C57BL/6 and C3H/HeN x C57BL/6 hybrid backgrounds. The 3d mutation was mapped to mouse chromosome 19 using a panel of microsatellite markers and at present, has been confined to 0.4 a Mbp critical region on 3000 meioses. 3d appears to encode a protein essential for TLR-mediated detection of nucleic acids, which is indispensable for effective innate defense against viral infection.
Killed but Metabolically Active Recombinant Listeria monocytogenes as an Antigen Delivery and Activation Platform for Human Dendritic Cell-Based Cancer Immunotherapy.
Authors: Brockstedt Dirk G. , Skoberne Mojca , Yewdall Alice , Bahjat Keith S. , Corash Larry , Dubensky Thomas W. , Bhardwaj Nina 
Published: October 2019

Abstract
Dendritic cells (DCs) are bone marrow-derived professional antigen presenting cells which play a pivotal role in initiating immune responses. To achieve optimal potency for priming of naive T cells, DCs must not only present high levels of MHC peptide complexes, but must also undergo maturation. An ideal DC-targeting vaccine formulation, therefore, should simultaneously deliver multiple antigens and activate DCs to increase expression of surface MHC-peptide complexes, costimulatory molecules, and production of immuno-stimulatory cytokines. Despite the development of a variety of ex vivo methods, no standard efficient and cost effective methods combining antigen loading and activation/maturation of DCs for clinical use currently exist. Here we report the development of a novel DC antigen-loading platform based on killed, but metabolically active (KBMA) recombinant Listeria monocytogenes (Lm). While recombinant Lm has a relatively long history as a cancer vaccine platform, its utility as a DC activation and loading platform has not been fully explored. KBMA Lm were 8-logs more sensitive to photochemical inactivation by the combined treatment of S-59 psoralen (amotosalen HCl) and long-wave ultraviolet light (S-59/UVA), by virtue of abrogation of nucleotide excision repair (NER) capacity, through engineered deletion of the bacterial UvrAB genes. Due to random distribution of infrequent psoralen adducts, KBMA Lm cannot propagate, but are metabolically active and can express their genetic repertoire, and program presentation of expressed heterologous antigens via the MHC class I and class II pathways. Infection of human monocyte-derived or blood myeloid DCs with KBMA Listeria induced their maturation and production of pro-inflammatory and pro- Th1 cytokines. The DCs achieved a fully mature phenotype, comparable to that induced by the standard maturation stimulus MCM-mimic. To determine whether KBMA Lm could program presentation of encoded antigens by the MHC class I pathway, we constructed a recombinant Lm vaccine expressing CD8+ T cell epitopes of influenza matrix protein (MP58–66) and MelanA/Mart-1 protein (Mart126–35). DCs infected with the recombinant KBMA Lm vaccine presented the recombinant class I epitopes and induced IFN-γ production by MP58–66- or Mart126–35-specific human CD8+ T cell clones. These studies demonstrate that KBMA Listeria is a novel and powerful ex vivo DC antigen loading platform combining a potent DC-maturation stimulus with the cytosolic delivery of recombinant antigen for presentation.
Anti-Tumor Activity of a Novel Immunosuppressant FTY720 in Multiple Myeloma.
Authors: Yasui Hiroshi , Hideshima Teru , Roccaro Aldo M. , Shiraishi Norihiko , Hamasaki Makoto , Ishitsuka Kenji , Kumar Shaji , Raje Noopur , Li Guilan , Tai Yu-Tzu , Podar Klaus , Chauhan Dharminder , Anderson Kenneth C. 
Published: October 2019

Abstract
Sphingosine and its metabolites are bioactive sphingolipids involved in lipid biosynthesis, signal transduction and apoptosis. FTY720, a synthetic sphingosine analogue of myriocine derived from culture filtrates of Isaria sinclairii, has been reported to interact with the sphingosine-1-phosphate specific G protein-linked receptors (S1P1, 3, 4 and 5) (Mandala S et al. Science, 2002) and alter the migration and homing of lymphocytes, thereby inhibiting the immune response (Matloubian M et al. Nature, 2004). Recent studies have also shown that FTY720 induces growth inhibition and/or apoptosis in human cancer cells in vitro as well as in vivo murine model (Azuma H et al. Cancer Research, 2002). To date, however, the biologic sequelae of inhibiting sphingosine-1-phosphate activity on multiple myeloma (MM) cells have not been demonstrated. In the present study, we examined whether FTY720 triggers anti MM activity. FTY720 induced potent cytotoxicity against MM cell lines including MM.1S, U266, RPMI8226, with IC50 at 24 h of 3.0 – 7.0 mM, assessed by trypan-blue exclusion and MTT assays. FTY720 also inhibited growth of doxorubicin (Dox)-resistant RPMI8226-Dox40 and dexamethasone (Dex)-resistant MM.1R cell lines, with IC50 values similar to the parental drug-sensitive cell lines. In contrast, no cytotoxicity of FTY720 was recognized against human peripheral blood mononuclear cells from normal healthy donors. The combination of Dex with FTY720 demonstrated enhanced cytotoxicity compared to either agent alone. Importantly, neither interleukin-6 (IL-6) nor insulin like growth factor-I (IGF-I), which induces MM cell growth and protection against Dex-induced apoptosis, protected against FTY720-induced growth inhibition. The anti-MM mechanisms of action of FTY720 were next studied, and FTY720 induced caspase-dependent apoptosis in MM cell lines: FTY720 triggers caspase−8, −9 and −3 cleavage, followed by PARP cleavage and DNA fragmentation, as confirmed by Western blotting and agarose gel electrophoresis, respectively. Moreover, FTY720 abrogated both IL-6 mediated phosphorylation of Akt-1, STAT3 and p42/44MAPK, and IGF-I mediated Akt-1 phosphorylation. Importantly, paracrine MM cell growth with bone marrow stromal cells was strongly inhibited by FTY720. These results suggest that FTY720 overcomes drug resistance in MM cells and, providing the rationale for its clinical evaluation to improve patient outcome in MM.
Comparison of Na18F and 18F-Deoxyglucose Positron Emission Tomography in Patients with Multiple Myeloma.
Authors: Troncy Jacques , Mercier Sylvie , Roy Pascal , Michallet Mauricette , Dumontet Charles M. , Janier Marc 
Published: October 2019

Abstract
Staging of patients with myeloma currently takes into account the number of bone lesions identified with standard X-rays. Magnetic Resonance Imaging (MRI) appears to be a more sensitive imaging technique in patients with multiple myeloma (MM) but it is not adapted to the investigation of the entire skeleton. Positron Emission Tomography (PET) imaging appears promising but this approach remains to be validated in patients with MM. Most patients with neoplasia have been performed with 18F-2-deoxy-D-glucose (FDG), a functional marker suggested to identify “active” tumor sites and useful to assess bone or extra-osseous tissue. Conversely Na18F binding is strictly limited to bone. To determine the potential usefulness of these two markers we performed a comparative analysis of these two imaging techniques in patients with MM.
Nine patients with progressive MM, including bone lesions, underwent x-ray imaging, MRI, 18FDG and Na18F scanning. Both PET scans were performed within a one-week time frame in each patient. The number and localizations of suspect lesions identified by each type of imaging technique was assessed independently then compared. 18FDG and Na18F data were compared to X-ray/MRI data for skull, spine, pelvis and femur/humerus localizations. Localizations were considered positive in case of increased fixation with 18FDG or increased or decreased fixation with Na18F.
Comparison of FDG data with X-ray/MRI showed that FDG allowed the detection of only 3 of 35 types of localizations identified by X-ray/MRI, whatever the localization (skull, femur/humerus, spine and pelvis) observed on X-ray/MRI. 18FDG showed three lesions which had not been identified by X-ray/MRI, as well as 8 costal localizations and 1 extra-osseous localization. Comparison of Na18F data with X-ray/MRI showed that Na18F allowed the detection of 17 of 35 types of localizations. In particular, Na18F identified 13 of the 19 spinal localizations observed with x-ray/MRI but only 2 of 9 skull lesions. Na18F identified 11 localizations which had not been identified by X-ray/MRI. Furthermore Na18F also identified costal localizations in all patients. Qualitative analysis of PET scans showed that background was significantly lower with Na18F imaging than with 18FDG imaging. In conclusion 18FDG and Na18F provide significantly different results in patients with progressive MM. 18FDG imaging was poorly correlated with X-rayMRI while Na18F imaging was particularly useful to identify costal and spinal lesions. PET scan could be a useful method in the staging of MM patients at diagnosis or to determine response.
Figure Figure