bluuebunny/crossref_metadata_2025_split huggingface dataset:
Combined Treatment with Short Synthetic Anti-Lymphoma Peptide and CpG ODN; A Therapeutic Vaccine Which cures the A20 Lymphoma in Balb/C Mice.
Authors: Kolstad Arne , Houot Roch , Berge Gerd , Rekdal Øystein , Czerwinski Debra , Goldstein Matthew , Brody Joshua , Levy R. 
Published: April 2020

Abstract
Background. The short synthetic peptide 302 has been shown to induce rapid membrane disruption of lymphoma cells in vitro and necrosis of local tumors in the A20 lymphoma model in Balb/c mice. In order to stimulate the immune system to generate an anti-tumor response we designed a model where intra-tumor injections of peptide 302 was combined with sc injections of the Toll-like receptor 9 binding synthetic oligonucleotide CpG 1826.
Methods. Balb/c mice were inoculated with A20 lymphoma cells sub-cutaneously (s.c.) on the abdomen. When the tumors reached a size of 5–7 mm, 302 peptide was administered directly into the tumors on days 1 and 6. CpG 1826 was injected s.c. on days 1–4 and 6–8. Tumor growth was measured repeatedly during follow-up. A20-specific T-cell responses were detected by culturing peripheral blood lymphocytes from treated animals for 24 hours with A20 lymphoma cells and analyzing for intracellular IFN-γ production by flow cytometry. To dissect the role of T-cell subtypes, the treatment was performed in animals depleted for CD4 or CD8 positive T-cells. In order to show A20 specific immunological memory, cured animals were re-challenged with the A20 lymphoma or the carcinoma cell line CT26.
Results. Combined treatment with peptide 302 and CpG 1826 cured 8 out of 10 mice, compared to only 2 out of 10 mice who received peptide 302 alone or CpG 1826 alone. Cured mice were followed for 9 weeks without relapsing. Similar results with the combination of peptide 302 and CpG were observed in a separate experiment. The highest cure rate was achieved when injecting CpG 1826 s.c. in the tumors draining lymph node area as compared to administration of CPG 1826 in a non-draining lymph node region or intra-peritoneal. Animals treated with peptide 302 + CpG 1826 or CpG 1826 alone developed CD8-specific IFN-γ responses against A20 cells. In one separate experiment CD8 knock-out mice did not respond to the treatment, unlike animals depleted for CD4+ cells and normal mice. Only 1 out of 10 cured animals re-challenged with the A20 lymphoma developed a new tumor, a result that was reproduced in a second experiment.
Conclusion: Treatment with intra-tumor injections of the anti-lymphoma peptide 302 in combination with CpG 1826 s.c. in the draining lymph node region cured established A20 tumors, induced tumor-specific CD8 positive tumor-reactive T-cells, and induced specific immunological memory. This principle represents a novel therapeutic vaccine approach.
Inhibition of Human Lymphoma Cell Growth by the PKC-Beta Selective Inhibitor Enzastaurin (LY317615) in Combination with Multiple Therapeutic Agents.
Authors: Rossi Randall M , Balys Marlene , Franklin Dean , Grose Valerie , Fisher Richard I , Jordan Craig 
Published: April 2020

Abstract
Previous studies in our lab have shown that the PKC-beta inhibitor, enzastaurin (LY317615), when used to treat a panel of human diffuse large cell lymphoma (DLCL) lines, was able to induce cell death in vitro and substantially reduce tumor growth in xenograft assays. These findings support the hypothesis that activation of PKC contributes to tumor cell survival and proliferation, which has been implicated in the pathogenesis of human B cell lymphomas. Specifically, PKC-beta activation is increased in tumor cells from patients with poor prognosis DLCL, suggesting that PKC-beta may be a target for therapeutic intervention. In the present study, we have explored the interaction of enzastaurin with a panel of well characterized therapeutic agents to evaluate whether its anti-tumor activity can potentially be enhanced. Drugs were chosen for analysis based either on known single agent activity in lymphoma, or by preclinical evaluation indicating potential synergy with enzastaurin. For in vitro culture assays (48–72 hr treatment), the addition of gemcitabine, rapamycin, or bortezomib, increased the cytotoxicity of enzastaurin from 2 to 7 fold. This effect was evident with multiple human DLCL cell lines, (OCI-Ly3, 7, 10, 19, and SUDHL-4, and 6), as well as two independent primary DLCL cultures. For in vivo studies, subcutaneous transplantation of the DLCL cell line OCI-Ly19, (previously engineered to express luciferase which allows for real time in vivo imaging), or a primary DLCL isolate, into immune deficient NOD/SCID mice formed reproducible tumors. Recipient animals were separated into uniform cohorts when the tumors were of &lt;=500 cubic mm in size. The animals were then simultaneously or sequentially treated with enzastaurin, (150 mg/kg b.i.d. via oral gavage) and a secondary drug, either gemcitabine, (2.5 or 5.0 mg/kg 1x/3 days IP), bortezomib, (0.4 mg/kg twice weekly IP), rapamycin, (1.0 mg/kg, daily IP), or rituxan, (5 mg/kg, weekly IP). Imaging and analysis of tumor volumes showed that addition of either rituxan or rapamycin provided no additional benefit in comparison to enzastaurin alone during the course of treatment. In contrast, the combination of either gemcitabine or bortezomib with enzastaurin demonstrated significantly reduced tumor volumes in comparison to enzastaurin alone (17% to 38% greater decrease with enzastaurin + gemcitabine, and 50% greater decrease in tumor volume with enzastaurin + bortezomib). These data suggest that the use of enzastaurin in combination with existing therapeutic drugs (gemcitabine or bortezomib) has the potential to limit tumor size/growth while lowering dose levels and thereby reducing potential side effects associated with traditional treatments.
Pharicin B, a Novel Diterpenoid, Stabilizes Retinoic Acid Receptor-α Protein and Induces Differentiation of AML Cells in the Presence of Physiological Doses of ATRA.
Authors: Chen Guo-Qiang , Gu Zhi-Min , Zhou Mei-Yi , Wu Ying-Li , Huang Ying 
Published: April 2020

Abstract
Retinoids, a generic term that covers compounds including both naturally dietary vitamin A (retinol) metabolites and active synthetic analogs, exert their pleiotropic effects such as anticancer activity through the three retinoic acid receptors (RARs) subtypes [RARα, RARβ and RARγ]. The most impressive example of retinoid anticancer activity is the successful application of all-trans retinoic acid (ATRA) in the treatment of patients with acute promyelocytic leukemia (APL), a unique subtype of acute myelogenous leukemia (AML) which characterized with the specific reciprocal chromosome translocation t(15;17) that results in the expression of leukemia-promoting promyelocytic leukemia-retinoic acid receptor-α (PML-RARα) chimeric protein. However, retinoid resistance frequently occurred in ATRA-treated patients. Isodon xerophilus, a perennial shrub native to Southern China, has been used as an anti-tumor, anti-inflammatory, and anti-microbial agent in Chinese herb medicine for a long history. During the past 30 years, a large number of ent-kauranoids have been isolated from the genus Isodon, many of which exhibit potent antitumor activities with a relatively low toxicity. In this work, we identified a novel ent-kaurene diterpenoid named pharicin B to rapidly stabilize RARα as well as PML-RARα protein in AML cell lines. More intriguingly, it also antagonizes ATRA-induced degradation of RARα and PML-RARα proteins. The interesting finding promotes us to investigate its possible effects on AML cells. Our results demonstrated that pharicin B at nontoxic concentration suppresses growth in APL cell line NB4 and myeloblactic leukemic U937 and THP-1 cell lines. Together with exceedingly low concentration of ATRA and RARα specific agonist AM580 existed, pharicin B significantly triggered all the three cell lines and some NB4-derived ATRA-resistant cell lines such as NB4-MR2 and NB4-LR1 (but not NB4-LR2) to undergo myeloid maturation, as evidenced by morphology, CD11/CD14 expression and NBT reduction test. All these results proposed that pharicin B would be a good tool for investigating mechanisms of RARα stabilization and degradation induced by ATRA as well as retinoid resistance, and its combination with ATRA might present the clinical potentials for differentiation-inducing therapy of APL and other AML patients.
Identification of p53 Aberration-Dependent as Well as Non-p53-Mediated Resistance to MDM2 Inhibitors in Acute Myelogenous Leukemia.
Authors: Long Jianting , Ouillette Peter , Parkin Brian , Erba Harry , Wang Shaomeng , Malek Sami 
Published: April 2020

Abstract
MDM2 inhibitors are under development as novel therapeutic agents in cancers and multiple such compounds have entered early-phase clinical trials. AML is characterized by a relatively low incidence of p53 mutations, thus constituting a tumor type that may have high response rates to MDM2 inhibitors.
We have measured apoptosis induction following ex-vivo treatment with the MDM2 inhibitors MI63 and MI-219 in highly purified AML blasts from 80 patients using Annexin-V FACS-based readouts at 40 hours post treatment. IC50 values for apoptosis induction were calculated using dose response curves and the program XLfit. Data were integrated with p53 exons 5–9 sequence data and p53 immunoblotting data before and after MDM2 inhibitor treatment.
Results: AML blast sensitivities to treatment with MI219 fell into three classes: sensitive with IC50 values &lt;2μM (22/80=28% of all cases), partial resistance with IC50 values ≥2 to &lt;10μM (32/80=40% of all cases) and resistant with IC50 &gt;10μM (26/80=32% of all cases). All eight cases with p53 exons 5–9 sequence mutations were resistant to MI-219. p53 immunoblotting analysis before and after MI219 treatment revealed that the vast majority of resistant cases with wild-type p53 exons 5–9 displayed wild-type p53 induction.
Conclusion: AML is characterized by a substantial proportion of cases with partial or complete resistance to MDM2 inhibitor treatment. Further, given that the majority of these cases display wild-type p53 induction after MDM2 inhibitor treatment, it can be concluded that post-p53 network defects confer blocks to apoptosis induction in resistant AML blasts. To identify and catalogue these defects we have begun expression array-based analysis of transcriptome differences in sensitive versus resistant cases, SNP 6.0 array-based analyses of genomic aberrations in sensitive versus resistant cases and targeted molecule interrogations.
In summary, our data provide important supportive information regarding the planned initiation of human clinical trials with MDM2 inhibitors in AML. Such trials may benefit from ex-vivo testing of AML blasts for sensitivity to MDM2 inhibitors as part of pre-enrollment patient selection.
Analysis of Aurora B Kinase in Non-Hodgkin’s Lymphoma.
Authors: Ikezoe Takayuki , Takeuchi Tamotsu , Nishioka Chie , Adachi Yoshihiro , Furihata Mutsuo , Koeffler H. Phillip , Yokoyama Akihito 
Published: April 2020

Abstract
Aurora B kinase is one of the key regulators of mitosis and has been reported to be over-expressed in a various malignancies including acute myelogenous leukemia; however, expression of Aurora B in non-Hodgkin’s lymphoma (NHL) and its role in lymphoma genesis remain to be fully elucidated. This study explored the levels of Aurora B in seventy four lymph nodes and tumor specimens excised operatively from individuals with various types of NHLs including diffuse large B cell lymphoma (n=22, DLBCL), follicular lymphoma (n=12, FL), Burkitt’s lymphoma (n=10, BL), mantle cell lymphoma (n=4, MCL), mucosa associated lymphoid tissue (n=4, MALT), adult T-cell leukemia/lymphoma (n=11, ATL), peripheral T-cell lymphoma (n=8, PTCL), and Hodgkin’s lymphoma (n=3, HL). Immunohistochemical examination found that DLBCL (11/22, 50 %) and BL (8/10, 80 %) cells highly (percentage of positive cells, &gt;20 %) expressed Aurora B in their nucleus. On the other hand, FL (11/12, 92 %), MCL (1/4, 25 %), and MALT (1/4, 25 %) cells slightly (percentage of positive cells, 5–20 %) expressed Aurora B and none of them, except for one case of FL, highly expressed this protein kinase, suggesting that expression of Aurora B correlated with histological grade in B cell NHLs (p=0.0004). We next examined whether Aurora B could be a molecular target for treatment of NHLs utilizing BALM-14, -18, and -27, Daudi, Ramos, and Raji Burkitt’s lymphoma/leukemia cells. Exposure of these cells to AZD1152, a selective inhibitor of Aurora B kinase, potently induced apoptosis in association with activation of caspase 3, as measured by annexin V staining and Western blot analysis, respectively. Moreover, we found that AZD1152 synergistically enhanced the effects of vincristine (VCR), a tubulin depolymerizing agent, to induce growth arrest and apoptosis of these cells. Further experiments found that VCR increased levels of the phosphorylated forms of Aurora B (p-Aurora B) via activation of c-Jun N-terminal kinase (JNK), which was blocked in the presence of AZD1152 in BALM-27 cells. Taken together, Aurora B kinase is a promising molecular target for treatment of individuals with aggressive types of NHLs. The combined administration of AZD1152 and the conventional chemotherapeutic agents to patients with NHL warrants further investigation.
Hedgehog Inhibitors Reduce the Survival and Drug Resistance in CD34+ Leukemic Cells.
Authors: Kobune Masayoshi , Murase Kazuyuki , Iyama Satoshi , Sato Tsutomu , Kawano Yutaka , Kikuchi Shohei , Miyanishi Koji , Takimoto Rishu , Kato Junji 
Published: April 2020

Abstract
Aberrant reactivation of Hedgehog (Hh) signaling has been described in a wide variety of human cancers and its role in maintenance of self-renewal of cancer stem cells. We previously showed that Indian Hh (Ihh) and its receptor molecules, Patched and Smoothened are expressed in cord blood (CB) CD34+ cells and Ihh regulate proliferation of hematopoietic myeloid- and lymphoid-repopulating cells in vivo. However, the involvement of Hh signaling in proliferation of leukemic cells has remained unclear. In this study, we assessed the possibility that Hh pathway activation contributes to the growth, survival and drug resistance of acute myeloid leukemic (AML) cells. Hh signaling in leukemic cell lines and bone marrow (BM) CD34+ cells were screened by RT-PCR and a Hh signaling reporter assay. We have found that Ihh were expressed in BM CD34+ cells and most of human AML cell lines, HL60, U937, KG1, Kasumi-1, Kasumi3 and TF-1. In contrast, Hh receptor components, Patched and Smoothened, were detected in BM CD34+ cells and cytokine responsible CD34+ AML cell lines such as Kasumi-1, Kasumi-3 and TF-1. Moreover, the downstream transcription factor GLI1 or GLI2 were expressed in BM CD34+ cells and these CD34+ cell lines, indicating that Hh signaling was active in these cells. We further assessed whether Hh signaling transmit to GLI1 using GLI1-responsive luciferase assay. GLI-responsive reporter plasmid (TK-6GBS-Luc) was transduced into these cells in the presence or absence of anti-Hh neutralizing antibody 5E1. TK-6GBS-Luc-transduced Kasumi-1, Kasumi-3 and TF-1 cells showed high luciferase activity. Furthermore, the luciferase activity of these cells was significantly reduced in the presence of 10 μg/ml anti-Hh neutralizing antibody. These results clearly indicate that Ihh signaling transmits into these CD34+ leukemic cell lines in autocrine manner. We next examined the effect of Hh inhibitors on these CD34+ leukemic cell lines. Inhibition of Hh signaling with the naturally derived chemical Smoothened antagonist Cyclopamine, endogenous Hh inhibitor Hedgehog-interacting protein or anti-Hedgehog neutralizing antibody reduces the entry of cell cycle of CD34+ cell lines and eventually induces apoptosis in these cells after 48 hr exposure although these CD34+ cell lines exhibit resistance to cytarabine (Ara-C) exposure. In contrast, cyclopamine did not affect growth and survival of the U937 or HL-60 cell line that lacks expression of Hh receptor components. Furthermore, combination of 10 μM cyclopamine significantly reduced the drug resistance against Ara-C in CD34+ cell lines. These results suggest that Hh pathway activation is a feature of CD34+ myeloid leukemic cells and inhibition of Hh signaling pathway may be a therapeutic strategy in the treatment of AML.
Identification of Heat Shock Protein 32 (Hsp32) as a Novel Target in Acute Lymphoblastic Leukemia (ALL).
Authors: Meyer Renata A. , Herrmann Harald , Gleixner Karoline V. , Gruze Alexander , Cerny-Reiterer Sabine , Hubmann Rainer , Shehata Medhat , Mayerhofer Matthias , Sperr Wolfgang R. , Pickl Winfried F. , Melo Junia V. , Bharate Gahininath Y. , Jäger Ulrich , Maeda Hiroshi , Valent Peter 
Published: April 2020

Abstract
Heat shock proteins (Hsp) are increasingly employed as therapeutic targets in various solid tumors and leukemias. We have recently shown that Hsp32 is expressed in leukemic cells and serves as a survival-factor and molecular target in Ph+ chronic myeloid leukemia. In the present study, we examined the expression and functional role of Hsp32 in acute lymphoblastic leukemia (ALL). Leukemic cells were obtained from patients with Ph+ ALL (n=5) and Ph− ALL (n=5). In addition, Ph+ ALL cell lines (Z-119, BV-173, TOM-1, NALM-1) and Ph− ALL cell lines (RAJI, RAMOS, REH, BL-41) were used. As assessed by immunocytochemistry and qRT-PCR, leukemic cells were found to express the Hsp32 protein as well as Hsp32 mRNA in all patients and in all cell lines examined. The Hsp32-inductor hemin was found to promote the expression of Hsp32 in leukemic cells. To determine the functional role of Hsp32 in lymphoblasts, an siRNA against Hsp32 was applied. The siRNA-induced knock down of Hsp32 in RAJI cells was found to be associated with reduced growth and with an increase in apoptotic cells compared to a control siRNA against luciferase (p&lt;0.05). In a next step, two pharmacologic inhibitors of Hsp32, pegylated zinc protoporphyrine (PEG-ZnPP) and styrene maleic acid-micelle-encapsulated ZnPP (SMA-ZnPP), were applied. As assessed by 3H-thymidine uptake experiments, both drugs were found to inhibit proliferation in the BCR/ABL+ cell lines Z-119, BV-173, and TOM-1, and in the BCR/ABL-negative ALL cell lines RAJI, RAMOS, REH, and BL-41. The effects of PEG-ZnPP and SMA-ZnPP were dose-dependent with IC50 values ranging between 1 and 10 μM, and were found to be associated with apoptosis as determined by microscopy as well as by flow cytometry and AnnexinV-staining. In NALM-1 cells, PEG-ZnPP and SMA-ZnPP also produced apoptosis and growth arrest, but the IC50 for SMA-ZnPP was slightly higher compared to other cell lines (20 μM). Effects of Hsp32-targeting drugs were also observed in primary leukemic cells obtained from patients with Ph+ ALL and Ph− ALL, with IC50 values ranging between 1 and 10 μM. No major differences were found when comparing results in imatinib-sensitive and imatinib-resistant patients. In drug combination experiments, Hsp32-targeting drugs were found to cooperate with imatinib and with AMN107 (nilotinib) in producing growth-inhibition and apoptosis in all Ph+ ALL cell lines tested. Furthermore, we were able to demonstrate strong cooperative antileukemic effects when applying Hsp32-targeting drugs in combination with bendamustine. Overall, these results suggest that Hsp32 may be a novel molecular target in ALL.
Targeting the Mnk Pathway Enhances Chemotherapy-Induced Antileukemic Responses.
Authors: Altman Jessica K , Glaser Heather , Redig Amanda , Sassano Antonella , Tallman Martin S , Platanias Leonidas C 
Published: April 2020

Abstract
Mnk kinases (mitogen-activated protein kinase [MAPK]-interacting kinases) are downstream effectors of Map kinase pathways, including the MEK/Erk and the p38 Map kinase signaling cascades. We have previously shown that Mnk kinases and the p38 Map kinase pathway are activated in a negative feedback regulatory manner during treatment of cells with arsenic trioxide, and that molecular or pharmacological inhibition of their activation enhances arsenic trioxide-dependent apoptosis and antileukemic responses (J Biol Chem. 283:12034–42, 2008, and Cancer Res. 66:6763–71, 2006). We examined the activation status of Mnk kinases in response to treatment of AML cells with chemotherapy and the function of these kinases in the generation of antileukemic responses. The human AML cell lines U937, K562, or MM6 were treated with cytarabine, in the presence or absence of a commercially available pharmacological Mnk-1 inhibitor (Calbiochem); and the phosphorylation of Mnk and its downstream effector, eIF4E, were assessed. Treatment with cytarabine increased phosphorylation of Mnk and eIF4E. The cytarabine-dependent eIF4E phosphorylation was blocked when human leukemia cell lines were treated with the pharmacologic Mnk inhibitor, indicating that Mnk regulates eIF4E activity. Such phosphorylation was also found to be defective in Mnk1/Mnk2 double knockout mouse embryonic fibroblast (MEF) cells, as compared to wild-type MEFs. Importantly, cytarabine-induced apoptosis was strongly enhanced in Mnk1−/− Mnk2−/− MEFs, as compared to Mnk1+/+Mnk2+/+ MEFs. To define the role of Mnk kinases in the generation of chemotherapy-induced antileukemic responses, human leukemia cell lines and bone marrow or peripheral blood mononuclear cells from patients with AML were used in clonogenic assays in methylcelluose to determine the effects of Mnk inhibition in the cytarabine-mediated leukemic progenitor (CFU-L) growth. The Mnk inhibitor potentiated the inhibitory effects of cytarabine on U937-derived CFU-L colonies and bone marrow or peripheral blood-derived CFU-L from 3 patients with AML. Interestingly, combinations of the Mnk inhibitor with the mTOR inhibitor, rapamycin, also resulted in more pronounced inhibitory effects on CFU-L colony formation than each agent alone. Altogether, these findings demonstrate that the Mnk pathway is activated during treatment of AML cells with cytarabine and that such activation occurs in a negative feedback regulatory manner to counteract the antileukemic effects of cytarabine. They also raise the possibility that targeting Mnk kinases may provide a novel approach to enhance the effects of chemotherapy on AML cells in vitro and possibly in vivo.