bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Ring-Substituted Diindolylmethane 1,1-bis [3′-(5-methoxyindolyl)]-1-(p-t-butylphenyl) Methane Abrogates ERK Activation and Induces Apoptosis in Acute Myeloid Leukemia (AML).
Authors: Contractor Rooha , Samudio Ismael J. , Estrov Zeev , Harris David , McCubrey James A. , Safe Stephen H. , Andreeff Michael , Konopleva Marina 
Published: October 2019

Abstract
We investigated the antileukemic activity and molecular mechanisms of action of a newly synthesized ring-substituted diindolylmethane (DIM) derivative, named, 1,1-bis [3′-(5-methoxyindolyl)]-1-(p-t-butylphenyl) methane (DIM #34), in myeloid leukemic cells. DIM #34 inhibited leukemic cell growth via induction of apoptosis. DIM #34 inhibited clonogenic growth and induced apoptosis of AML CD34+ progenitor cells but spared normal progenitors. DIM #34 induced loss of mitochondrial membrane potential, which was accompanied by the release of cytochrome c into the cytosol and early cleavage of caspase-9 followed by the cleavage of caspases -8, and -3. Bcl-2 overexpression and caspase-9-deficient cells were partially protected against DIM #34-induced apoptosis, suggesting activation of the intrinsic apoptotic pathway. DIM #34 induced Bax cleavage, and Bax knockout cells were partially resistant to cell death. Furthermore, DIM #34 transiently inhibited the phosphorylation and the activity of the extracellular-regulated kinase (ERK) and abrogated Bcl-2 phosphorylation. Because other methylene substituted DIM analogs transactivate the nuclear receptor PPARγ, we studied the role of PPARγ in apoptosis induction. Although the co-treatment of cells with a selective PPARγ antagonist T007, and a low dose of DIM #34 partially diminished apoptosis, apoptosis was not inhibited at higher concentrations of DIM #34, suggesting the involvement of both, receptor-dependent and independent mechanisms. Co-treatment with RXR- and RAR-ligands enhanced DIM #34-induced cell death. Together, these findings showed that substituted DIMs represent a new class of compounds that selectively induce apoptosis in AML cells through interference with ERK and activation of PPARγ signaling pathways.
CD26/Dipeptidyl Peptidase IV (DPPIV) Regulates p38 Phosphorylation and Topoisomerase II Alpha Expression in the B-Lymphoma Line Jiyoye, Associated with Enhanced In Vitro and In Vivo Sensitivity to Doxorubicin.
Authors: Yamochi Toshiko , Yamochi Tadanori , Aytac Ugur , Sato Tsutomu , Morimoto Chikao , Dang Nam H. 
Published: October 2019

Abstract
CD26 is a 110 kDa surface glycoprotein with diverse functional properties, including having a key role in normal T-cell biology, being a marker of aggressive disease for selected T-cell malignancies and being involved in the development of certain cancers. Its extracellular domain encodes a membrane-associated dipeptidyl peptidase IV (DPPIV) activity capable of processing biological factors to alter their functional profiles. We have shown previously that expression of CD26 on the T cell line Jurkat is associated with increased topoisomerase II alpha level and in vitro sensitivity to topoisomerase II inhibitors (Aytac U et al. Cancer Res61:7204, 2001; Aytac U et al. Br J Cancer88:455, 2003; Sato K et al. Br J Cancer89:1366, 2003). We now show that CD26 expression, particularly its DPPIV enzyme activity, on the B-lymphoma line Jiyoye results in increased topoisomerase II alpha level and in vitro sensitivity to doxorubicin-induced apoptosis. Examining the molecular mechanisms involved in CD26-associated signaling, our present findings also indicate that CD26/DPPIV expression on Jiyoye cells is associated with increased phosphorylation of p38 and its upstream regulators MKK3/6 and ASK1. Importantly, inhibition of p38 phosphorylation decreases topoisomerase II alpha expression, suggesting a role for p38 in the regulation of topoisomerase II alpha. Finally, studies using a SCID mouse xenograft model with CD26 Jiyoye transfectants show that CD26 expression is associated with enhanced survival following treatment with low doses of doxorubicin. In particular, treatment with low-dose doxorubicin of SCID mice injected with CD26-negative parental Jiyoye cells does not lead to a statistically significant survival advantage over those treated with saline. On the other hand, SCID mice injected with CD26 Jiyoye transfectants show significantly greater survival when treated with low-dose doxorubicin than with saline alone, indicating that CD26 presence renders tumor cells more sensitive to doxorubicin in an in vivo model. Our data thus characterize the biochemical linkage among CD26 and other key intracellular molecules, while demonstrating that CD26 may have a role in tumor sensitivity to antineoplastic agents targeting topoisomerase II alpha. In addition, our work suggests that CD26/DPPIV may be an appropriate target for therapy for selected hematological malignancies of both B- and T-cell lineages.
Molecular Mechanisms Underlying the Development of Drug Resistance in Multiple Myeloma.
Authors: Shammas Masood A. , Koley Hemant , Li Cheng , Anderson Kenneth C. , Reis Robert J. S. , Munshi Nikhil C. 
Published: October 2019

Abstract
A prominent feature of most cancers including multiple myeloma (MM) is a striking genetic instability, leading to ongoing accrual of mutational changes some of which underlie tumor progression, including development of drug resistance and metastasis. The molecular basis for the generation of genetic diversity in cancer cells has thus emerged as an important focus of investigation and a target for successful eradication. We have previously observed that homologous recombination (HR) is upregulated in MM. Utilizing a genomewide LOH assay based on SNP genotyping (Affymetrix) as a tool to estimate the rate of mutation and genomic instability, we have observed that over time elevated HR leads to progressive accumulation of genetic variation in MM cell lines and patient cells; and inhibition of HR activity in MM cells by altering components of the HR pathway concordantly affects the acquisition of new genetic changes. As HR activity is dependent on concerted action of number of genes, instead of over expressing single HR related gene, we utilized nickel chloride, a known recombinogen to evaluate effects of increased HR activity on the development of genomic diversity. We cultured ARP cells in the presence or absence of nickel chloride, over a period of 90 days. Genome-wide LOH was evaluated by comparing genotypes before and after the 90-day interval. In three independent experiments treatment of cells with nickel chloride increased the number of new LOH sites by more than 12-fold. We next evaluated the effect of induction of HR and the consequent increase in genetic aberrations, on development of drug resistance in MM. Myeloma cells were cultured with nickel chloride as a potent inducer of HR and dexamethasone (10−8M); control cells were exposed to dexamethasone alone. The cell viability was measured weekly. No live cells were detected in cultures exposed to dexamethasone alone; while &gt;95% cells exposed to both nickel chloride and dexamethasone were alive following 2 weeks culture. These findings were confirmed by 3 independent experiments. The development of drug resistance was further confirmed by demonstrating no significant effects of dexamethasone on these cells at 10−6M concentrations for &gt;1 week. Dexamethasone at this concentration kills all control cells by day 3. Evaluation of development of resistance to other agents is underway. We propose that continued accumulation of new genetic changes mediated by HR, as demonstrated here, provides the molecular events required to develop drug resistance; and its inhibition may allow us to successfully treat MM cells without the currently observed development of resistance. HR may be a potential therapeutic target to maintain chemo sensitivity of the tumors.
JS-K, a Novel Nitric Oxide (NO) Generator, Induces Cytochrome c Release and Caspase Activation in HL-60 Myeloid Leukemia Cells.
Authors: Shami Paul J. , Udupi Vidya , Yu Margaret , Malaviya Swati , Saavedra Joseph E. , Keefer Larry K. 
Published: October 2019

Abstract
NO induces differentiation and apoptosis in Acute Myelogenous Leukemia (AML) cells. Glutathione S-Transferases (GST) play an important role in multidrug resistance and are upregulated in 90% of AML cells. We have designed a novel prodrug class that releases NO on metabolism by GST. O2-(2,4-Dinitrophenyl) 1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate (JS-K, a member of this class) has potent antileukemic activity. We have previously shown that JS-K induces apoptosis in HL-60 cells by a caspase dependent mechanism (Molecular Cancer Therapeutics2:409-417,2003). The purpose of this study was to determine the pathway through which JS-K induces apoptosis. Western blot analysis showed that treatment of HL-60 cells with JS-K (0 – 1 μM) for 6 hours results in release of Cytochrome c from mitochondria in a dose dependent fashion. Treatment with JS-K resulted in a dose dependent activation of Caspase 9. Sixteen and 24 hours after exposure to 1 μM JS-K, Caspase 9 activity was induced by 393 ± 93% and 237 ± 13% of control, respectively (p = 0.03 at the 24 hours time point). Treatment with JS-K resulted in a dose dependent activation of Caspase 3. Twenty four hours after exposure to 1 μM JS-K, Caspase 3 activity was 208 ± 3.4 % of control (p = 0.02). Treatment with JS-K also resulted in a dose dependent activation of Caspase 8, but to a lesser extent than Caspase 9 and 3. Twenty four hours after exposure to 1 μM JS-K, Caspase 8 activity was 144 ± 5.3 % of control (p = 0.04). We conclude that JS-K activates the intrinsic pathway of apoptosis in leukemia cells by inducing the release of Cytochrome c from mitochondria. (NO1-CO-12400).
CD40-Activation of Chronic Lymphocytic Leukemia Cells Induces Latent Sensitivity to Fas/TRAIL-Mediated Apoptosis Via a P53-Independent, C-Abl-Dependent Pathway.
Authors: Kater Arnon P. , Dicker Frank , Fukuda Tetsuya , Kipps Thomas J. 
Published: October 2019

Abstract
Patients with chronic lymphocytic leukemia (CLL) experienced rapid reductions in leukemia cell count and lymph node size following an intravenous infusion of autologous CLL cells that were transduced to express a recombinant ligand for CD40 (CD154), including patients with leukemia cells that had inactivating mutations in P53 . Subsequent studies demonstrated that ligation of CD40 on CLL cells induced latent sensitivity to Fas (CD95)-dependent apoptosis and that this might account, in part, for the early reductions in leukemia cell counts observed in patients treated with CD154 gene therapy (Proc Natl Acad Sci U S A 100:3854–9, 2002). We found that ligation of CD40 induces CLL cells to express P53, as well as P53-dependent genes encoding CD95, DR5, and p21. Similar effects were observed following treatment of CLL cells with γ-radiation. In contrast to the effects of γ-radiation, however, CD40-ligation also induced CLL cells to express high-levels of Bid, a pro-apoptotic protein that mediates cross talk between extrinsic death receptors and mitochondrial-dependent apoptotic pathways. CLL cells that had inactivating mutations in P53 also were induced to express CD95, DR5, p21, and Bid following CD40-ligation, but not following γ-radiation, demonstrating that the gene expression response to CD40-ligation is dependent on a factor(s) other than p53. A good candidate for this is P73, a member of the P53 gene family that has been implicated in lymphocyte activation-induced cell death. Consistent with this notion, we found that ligation of CD40 on CLL cells induced expression of the α isoform of P73. The induction of P73 and latent sensitivity to CD95 (and TRAIL)-mediated apoptosis could be inhibited with the c-abl kinase inhibitor, imatinib mesylate, when added at the time of CD40-ligation. However, transduction of leukemia cells with a mutant gene encoding a c-abl kinase resistant to imatinib mesylate resulted in CLL cells that could be induced by CD40-ligation to express P73 and Bid even in the presence of imatinib mesylate. We conclude that sensitization to CD95-mediated apoptosis following CD40-activation is via a p53-independent, c-abl-kinase dependent process that is associated with activation of p73. Unlike p53, p73 mutations are extremely rare in human cancer. As such, CD154-based immune gene therapy may have activity even in patients who have CLL cells with dysfunctional P53 that are resistant to many of the anti-leukemia drugs currently used in the treatment of this disease.
Bmi-1 Expression Predicts the Progression of Malignant Hematopoietic Stem Cells in Myelodysplastic Syndrome.
Authors: Mihara Keichiro , Nakaju Nanae , Hidani Sachiko , Chowdhury Moniruddin , Ihara Akihiro , Kimura Akiro 
Published: October 2019

Abstract
Bmi-1 is a member of the Polycomb group (PcG) of transcriptional repressor genes, which could have an essential role in embryogenesis and be expressed restrictedly in the stem cells and proliferating cells. Some studies have recently reported that Bmi-1 is required to regulate the adult self-renewing hematopoietic stem cells. Others have shown that overexpressed Bmi-1 gene could cause the neoplastic proliferation of cells. A series of evidence on Bmi-1 suggests that it might be closely associated with the progression of the hematopoietic malignancies. Myelodysplastic syndrome (MDS) is a clonal bone marrow disorder characterized by aberrant hematopoiesis susceptible to acute leukemia. This category is quite heterogeneous with a variable clinical course and prognosis. Therefore, it is difficult to decide when to initiate therapies because some patients survive for years without treatment whereas others come to die in rapid progress in overt leukemia. Thus, we investigated whether the expression of Bmi-1 protein in CD34+ cells could be correlated with disease progression of MDS. Primary cells from patients with RA, RAEB, and MDS-AML, were stained with anti-CD34 antibody-PE and then fixed in PFA followed by staining with anti-Bmi-1-antibody-FITC. These cells were subjected to flow cytometric analysis. Bmi-1 expression in CD34+ cells was preferentially seen in RAEB and MDS-AML compared with RA (13.86%±6.40% in RA(n=4), 63.05%±8.19% in RAEB(n=6), 73.99%±33.40% in MDS-AML(n=6)). Patients were dead with >70% at Bmi-1 expression level in CD34+. Moreover, two patients with RA at >10% of Bmi-1 positivity made disease progression to RAEB. One patient with RAEB at <10% at the Bmi-1 expression in CD34+ is still alive. Furthermore, we are dissecting gene profiling of cells from different types of MDS. These results show that the expression of Bmi-1 can distinguish the proliferating malignant stem cells from resting cells by using flow cytometry. Alternatively, IPSS in MDS patients is closely correlated with Bmi-1 expression of CD34+ cells. It may lead to the prediction of prognosis in patients with MDS in quality. Taken together, Bmi-1 expression could predict the disease progression and prognosis of MDS. Finally, Bmi-1 gene might be a target to control leukemogenesis by immunotherapy or gene therapy.
Identification and Hematopoietic Potential of CD45-Negative Clonal Cells with Very Immature Phenotype (CD45−CD34−CD38−Lin−) in Patients with Myelodysplastic Syndromes.
Authors: Ogata Kiyoyuki , Satoh Chikako , Tachibana Mikiko , Hyodo Hideya , Tamura Hideto , Dan Kazuo , Kimura Takafumi , Sonoda Yoshiaki , Tsuji Takashi 
Published: October 2019

Abstract
CD45 is a hematopoietic lineage-restricted antigen that is expressed on all hematopoietic cells except for some mature cell types. Cells expressing CD45 and CD34 but lacking CD38 and lineage antigens (CD45+CD34+CD38−Lin− cells) are well-documented hematopoietic stem cells (HSCs), and CD45+CD34−CD38−Lin− cells are probably less mature HSCs. In myelodysplastic syndromes (MDS), the malignant transformation site was reported to be committed myeloid progenitors and, more recently, the CD45+CD34+CD38−Lin− HSCs. In this study, we detected CD45−CD34−CD38−Lin− cells in the peripheral blood and bone marrow of MDS patients. Fluorescence in situ hybridization showed that CD45−CD34−CD38−Lin− cells had the same chromosomal aberration as the myeloblasts. In addition to CD45- and CD34-negativity, they lacked CD117 and CD133 expressions. Generally, MDS cells have extremely reduced hematopoietic potential compared with normal hematopoietic cells, but we documented the following in some cases. Freshly-isolated CD45−CD34−CD38−Lin− cells did not form any hematopoietic colonies but had long-term culture-initiating cell activity. When these cells were co-cultured with stroma cells, CD45−CD34−CD38−Lin− cells showed only weak potential for proliferation/differentiation, yet differentiated to CD34+ cells and then mature myeloid cells. This newly-identified cell population represents the most immature immunophenotype so far identified in the hematopoietic lineage and is involved in the malignant clone in MDS.
Evidence for PTEN Deficiency in Juvenile Myelomonocytic Leukemia.
Authors: Liu Y. Lucy , Xu Likang , Castleberry Robert P. , Emanuel Peter Dean 
Published: October 2019

Abstract
Juvenile myelomonocytic leukemia (JMML) is a myelodysplastic/myeloproliferative disorder (MDS/MPD) of young children. It is characterized by monocytosis, leukocytosis, elevated fetal hemoglobin, hypersensitivity to granulocyte-macrophage colony-stimulating factor (GM-CSF), low percentage of myeloblasts in bone marrow, and absence of the Philadelphia chromosome. The pathogenesis of JMML has been linked to dysregulated signal transduction through the NF1/RAS signaling pathway and PTPN11. This dysregulation results in JMML cells demonstrating selective hypersensitivity to GM-CSF in vitro dose-response assays. PTEN, a major negative regulator of the PI3-kinase pathway by virtue of its PIP3 phosphatase activity, was initially isolated as a tumor suppressor in a variety of malignancies. In order to evaluate the role of PTEN in the pathogenesis of JMML, we examined the status of PTEN in JMML patient samples. Peripheral blood or bone marrow was collected from 40 patients. Mononuclear cells (MNCs) were isolated and lysed in lysis buffer at a concentration of 107/ml. Total RNA was extracted from MNCs of patients and 17 normal individuals. Protein and mRNA levels of PTEN were evaluated by Western-blot and relative-quantitative real-time RT-PCR, respectively. We found that PTEN protein was decreased in 18 of 30 (60%) JMML patients, and the patients had significantly lower RNA expression of PTEN than normal controls (p=0.015). With the available samples we also evaluated AKT activity and MAP kinase (MAPK) levels. We found that MAPK levels were correlated well with the status of the PTEN in 12 of 27(44%), and AKT activity in 13 of 25 patients (52%). Our data indicates that PTEN is significantly deficient in JMML patients, and the low PTEN protein level is related to its low transcription of RNA in JMML patients. The role of PTEN in regulation of MAPK and AKT activities in JMML is under further evaluation by studying the upstream status of the RAS pathway prior to PTEN. This is the first investigation of PTEN deficiency in JMML patients, and additional investigations may help to further understand the pathogenetic mechanisms in JMML, as well as to guide the development of targeted therapeutics for JMML.
The STK Receptor Tyrosine Kinase Regulates the Response of Primary Macrophages to LPS in a Ligand-Independent Manner.
Authors: Correll Pamela , Liu Qingping Liu 
Published: October 2019

Abstract
We have shown previously that activation of the STK/RON receptor tyrosine kinase expressed on tissue resident macrophages, by it’s ligand macrophage stimulating protein (MSP), results in the inhibition of NFkB activation, inducible nitric oxide synthase (iNOS) expression and TNFa production, as well as the induction of arginase expression, suggesting a role for this receptor in the regulation of classical vs. alternative macrophage activation. Furthermore, mice with a targeted deletion in this receptor exhibit increased sensitivity to endotoxic shock and DTH responses. More recently, we have demonstrated that MSP stimulation of primary peritoneal macrophages inhibits the production of IL-12. In order to map the domains of STK responsible for the inhibition of classical macrophage activation by MSP, we generated mutant forms of the receptor and expressed wild-type and mutant receptors in primary bone marrow derived macrophages by retroviral transduction. Expression of wild-type STK in these primary cells resulted in the ligand-independent reduction in IL-12p40 production in response to LPS stimulation, which was further inhibited by MSP treatment. This is consistent with the lack of a requirement for MSP in regulating responses to endotoxin in vivo. Surprisingly, a kinase dead receptor, which fails to signal in 293T cells, was fully functional in this assay, suggesting that the kinase activity of the receptor is not required for the inhibition of IL-12p40 under these conditions. However, the docking site tyrosines in the c-terminal tail of the receptor are essential for the inhibition of IL-12p40 by STK, suggesting that STK may be phosphorylated by an another kinase in this system. STK/RON has been shown to associate both physically and functionally with a number of other cell-surface receptors including EpoR, IL-3R bc, EGFR, MET as well as a number of integrins and cadherins. We have shown previously that STK regulates the activity of the aMb2 integrin (CR3) in peritoneal macrophages in a PI3K, PKCz-dependent manner. Here we show that STK also physically associates with CR3, as well as CD14, in RAW264.7 cells in the absence of ligand. Both CR3 and CD14 are capable of directly binding to LPS. Thus, we speculate that STK may exist as part of a receptor complex in macrophages and that signalling through STK might be induced directly by LPS. This would provide a means by which STK could temper the response of tissue-resident macrophages to LPS thereby preventing damage to host tissues.