bluuebunny/crossref_metadata_2025_split huggingface dataset:
PS-341 Induces Selective Radiosensitization of Multiple Myeloma Cells.
Authors: Goel Apollina , Dispenzieri Angela , Greipp Philip R. , Witzig Thomas E. , Mesa Ruben A. , Russell Stephen J. 
Published: April 2020

Abstract
Sublethal doses of ionizing radiation induce a complex cellular survival response, one component of which is activation of the nuclear factor kappa B (NF-kB) pathway. PS-341 is a selective inhibitor of the 26S proteasome which prevents the proteasomal degradation of I-kB and thereby inhibits the activation of NF-kB. We therefore hypothesized that PS-341 should synergistically enhance the anti-myeloma effect of ionizing radiation (IR). The individual and combined effects of PS-341 and IR were analyzed using human MM cell lines (MM1, RPMI 8226, JJN-3 and ARH-77) and bone marrow samples from myeloma patients.
Treatment of myeloma cell lines with 10nM PS-341 produced a modest anti-proliferative effect with G2/M-phase arrest and p21cip/waf-1 induction but minimal procaspase-3 cleavage and minimal apoptotic cell death: Similar sublethal damage was observed after single exposure to IR at a dose of 6 Gy. In contrast, sequential exposure to PS-341 (10 nM) and IR (6 Gy) resulted in potent (synergistic) induction of apoptosis, assayed by both fluorescein isothiocyanate conjugated annexin V-propidium iodide assay and cell cycle analysis. Overall cell viability was greatly reduced by the combination of PS3451 and IR, but not by either modality alone, as determined by 3-(4,5 dimethylthiazol-2yl) 2–5 diphenyltetrazolium bromide (MTT) assay and analysis of polyadenosine-5′-diphosphate-ribose polymerase (PARP) cleavage -product after 72 hours. As predicted, exposure to 6 Gy IR led to potent induction of nuclear NF-kB activity and this response was almost completely inhibited by simultaneous treatment with PS-341. The combination of PS341 and IR was next evaluated on CD138+ve and CD138-ve cell fractions from bone marrow aspirates of myeloma patients. Synergistic killing of primary myeloma (CD138+) cells was observed with relative sparing of normal marrow elements (CD138−). We conclude that PS-341 is a potent radiosensitizer for myeloma cell lines and primary myeloma cells. This provides a strong rationale to combine PS-341 with conventional external beam or with targeted radionuclide therapy for effective treatment of MM patients.
Phase II Study of Oxaliplatin in Patients with Relapsed or Refractory Non-Hodgkin’s Lymphoma: Final Results.
Authors: Oki Yasuhiro , McLauhlin Peter , Pro Barbara , Hagemeister Frederick H. , Bleyer Archie , Loyer Evelyn , Younes Anas 
Published: April 2020

Abstract
Many patients with NHL suffer from refractory or relapsed disease, and platinum-based combination therapy is widely used for salvage therapy. Oxaliplatin, a novel platinum derivative, is a more potent cytotoxic agent than cisplatin, demonstrating greater efficacy against many tumor cell lines, including lymphoma cell lines. Clinical studies of oxaliplatin for other malignancies have shown a favorable toxicity profile. The objective of this phase II trial was to investigate the activity of oxaliplatin in patients with relapsed or refractory non-Hodgkin’s lymphoma (NHL). Patients with measurable NHL who had experienced failure of one or more prior chemotherapy regimens were considered eligible. They were required to have an ECOG performance status £ 2 and adequate organ function. Patients were excluded if they had HIV infection, CNS lymphoma, or had chemotherapy or radiotherapy within 4 weeks prior to entering the study. All patients gave their written informed consent to participate. Oxaliplatin was administered at 130 mg/m2 every 21 days for up to six cycles in the absence of progression. Thirty-one patients (23 with aggressive NHL, 8 with indolent NHL) were enrolled on this trial. Thirty eligible patients received oxaliplatin, who were all assessable for toxicity. Response and survival were also analyzed in all 30 patients based on intention to treat analysis. The median patient age was 62 years, and most of the patients had an ECOG performance status of 0 or 1. The most common toxic effect was sensory neuropathy (87%). Grade 3 and 4 toxic effects included sensory neuropathy (10%), neutropenia (17%), and thrombocytopenia (20%). Objective responses occurred in 8 (27%) of the patients: 7 with aggressive NHL, 1 with indolent NHL. The median failure-free survival duration in the entire group, aggressive NHL group and indolent NHL group was 3.0, 2.1 and 4.0 months, respectively. It is noteworthy that three of the five patients with MCL (60%) had a significant response to oxaliplatin, including two CRus, with a median FFS duration of 5 months. When patient group is divided by IPI score (0/1 and 2 /3), the median FFS duration was 3.4 months and 2.6 months, respectively. Median response duration for entire group was 3.0 months. In summary, oxaliplatin has modest activity in patients with previously treated NHL, especially those with aggressive disease. The favorable toxicity profile of oxaliplatin warrants further investigation of it either in combination chemotherapy or with targeted biologic therapy.
Sapphyrins Exhibit Tumor Selectivity and Efficacy in Animal Models of Hematologic Malignancies.
Authors: Naumovski Louie , Sirisawad Mint , Lecane Philip , Ramos Jason , Magda Darren , Wang Zhong , Thiemann Patti , Boswell Garry , Cho Dong-Gyu , Sessler Jonathan , Miller Richard A. 
Published: April 2020

Abstract
Sapphyrins are pentapyrrolic metal-free expanded porphyrins that localize to tumors. We have previously demonstrated that sapphyrins induce apoptosis in a variety of hematologic tumor cell lines including lymphomas (Ramos, DHL-4, HF-1), leukemias (Jurkat, HL-60), and myelomas (8226/S, 1-310, C2E3, 1-414). Through chemical modification of the parent compound, PCI-2000, a number of derivatives were generated and tested for induction of apoptosis in Ramos cells. PCI-2000 and one of the more potent apoptosis-inducing derivatives, PCI-2050, were injected into CD-1 nude mice bearing Ramos xenografts. Animals were sacrificed 48 hrs after injection and analyzed for drug uptake in the tumor, liver and spleen using flow cytometry. For PCI-2000, the relative uptake was spleen&gt;tumor&gt;liver. For PCI-2050 the relative uptake was tumor&gt;spleen&gt;liver, suggesting that PCI-2050 preferentially localizes in tumors compared to PCI-2000. Tumor cells isolated from PCI-2050 treated animals grew less well in culture and had more apoptotic cells than those derived from PCI-2000 or control animals. Uptake of PCI-2050 into xenograft tumor cells and tumor cell killing was dose dependent. PCI-2050 (10 umol/kg x 2 days in a row) was administered to Ramos xenograft bearing animals that were then monitored for tumor growth. In both minimal tumor (animals treated before tumor was palpable) and established tumor (palpable tumor) models, PCI-2050 reduced tumor growth by 60–75%. Alternative dosing strategies revealed that split dosing (allowing 1 or more days between doses) was more efficacious in tumor control than dosing 2 days in a row. At the doses used in this study, there was no myelosuppression or lymphosuppression, hepatic or renal abnormalities as assessed by complete blood count and comprehensive serum chemistry analysis, respectively. Our work demonstrates that PCI-2050 induces apoptosis in tissue culture and inhibits tumor growth in an animal tumor model while exhibiting minimal toxicity. PCI-2050 and other sapphyrin derivatives will be further evaluated as potential anti-cancer agents.
Consolidation with Alemtuzumab in First Remission Induces Pronounced MRD Reduction and Clinical Remissions - Update on a Randomized Phase III Trial of the German CLL Study Group (GCLLSG).
Authors: Ritgen Matthias , Schweighofer C. , Fingerle-Rowson Günther , Eichhorst Barbara , Busch Raimunde , Stilgenbauer Stephan , Döhner Hartmut , Kneba Michael , Hallek Michael , Wendtner Clemens M. 
Published: April 2020

Abstract
The monoclonal antibody alemtuzumab is known to be effective in combination or alone in patients with late stage chronic lymphocytic leukaemia. Flow cytometric studies on minimal residual disease (MRD) showed the high potency beyond clinical response criteria even in late stage chronic lymphocytic leukaemia (CLL). The aim of the phase III trial of the GCLLSG was to investigate the role of alemtuzumab as consolidation therapy in CLL patients in first clinical remission after fludarabin (F) or F plus cyclophosphamide (FC).
Patients in partial or complete clinical remission were randomized to either arm A (alemtuzumab 3 x 30 mg i.v. for up to 12 wks) or no further treatment (arm B). From 21 eligible patients 11 (1CR, 1 nPR, 9PR) were randomized to arm A. All patients received standard infection prophylaxis with famciclovir and trimethoprim/sulfamethoxazole. Before, at 6 and 12 weeks after start of consolidation therapy and regulary during follow up blood and bone marrow samples were send for molecular MRD assessment by allele specific real time PCR. The PCR allowed MRD assessment with a sensitivity of at least 10E-4 in 11 eligible cases.
Results: MRD analysis showed clear reduction of CLL content by first line treatment to a median MRD level of 2.2E-3. Short after alemtuzumab treatment all treated patients showed pronounced MRD reduction to a median MRD level of 5.0E-5. During molecular follow-up median MRD level remained below 1E-4 for one year with a tendency to increase afterwards. After a median follow-up of 31.3 months from start of initial treatment occurred one relapse in the treatment arm compared to 7 of 10 in arm B. The median progression free survival (PFS) calculated from start of consolidation therapy was significantly shorter in the control group versus the treatment group (pfs 25.2; p= 0.04). Nevertheless due to severe acute infections (CTC III and IV) this study had to be stopped prematurely.
Conlusion: The addition of alemtuzumab as a consolidation regimen after remission induction by F or FC is highly effective and leads to sustained MRD reduction below 10E-4. This translates into significant improved clinical outcome even in this small patient cohort compared to the control group. Encouraged by the molecular responses the GCLLSG initiated a new phase I/II trial as a dose finding study in CLL patients after F based induction of clinical remission.
Rituximab® and High Dose Methylprednisolone (HDMP) for the Treatment of Patients with Relapsed/Refractory Chronic Lymphocytic Leukemia.
Authors: Castro Januario E. , Bole Jan , Prada Carlos E. , Kipps Thomas J. 
Published: April 2020

Abstract
High-dose gluocorticoids and the anti-CD20 mAb Rituximab each can effect partial responses in patients with chronic lymphocytic leukemia (CLL), although complete and durable responses to treatment with either of these agents have not been reported. We examined whether patients with relapsed and/or refractory CLL could respond to these agents when used in combination in a pilot clinical trial. Fourteen patients with progressive, symptomatic, and relapsed/refractory disease were treated with three four-week cycles of high-dose Methylprednisolone (HDMP) at 1gr/m2 daily for 5 days and weekly Rituximab® at 375mg/m2 for four weeks. The median age of the patients was 60 years, the male to female ratio was 4:1, the ECOG performance status was &lt; 2, and the average number of prior treatments was 2. All patients failed or were intolerant to fludarabine and 86% had high-risk disease by the modified Rai classification. Sixty-five percent of the patients had CLL cells that expressed ZAP-70 and unmutated immunoglobulin variable region genes. Response assessment was performed at the end of each cycle, two months after completion of treatment, and each 3–6 months thereafter until the patients experienced disease progression and/or required further treatment. Objective responses were observed in all 14 patients, with 6 patients achieving a complete response (CR) and the remainder a partial response (PR) as per the NCI-working group criteria. We observed a significant decrease in peripheral white blood cell (WBC) counts, increase in hemoglobin, elevation of platelet counts and a dramatic decrease in lymphadenopathy and splenomegaly. Five of the treated patients have not required further treatment with a median follow up of 26 months. Of these 5 patients 3 have maintain a CR. The median time to progression (TTP) was 12 months. Overall, the treatment was well tolerated and all the patients, except one, completed 3 cycles of therapy. The majority of adverse events were Grade I-II (fluid retention, cough, transient hyperglycemia, fatigue). In addition, we observed 7 episodes of grade III-IV toxicity secondary to (anemia, CMV esophagitis and GI bleeding with one case each and two cases each of thrombocytopenia and neutropenia). These data suggest that treatment with the combination of Rituximab® and HDMP has increased activity over treatment with either agent alone and may produce durable complete responses in patients with refractory and / or relapsed CLL.
Genistein Promotes Apoptosis, Differentiation and Cell Cycle Arrest in All Trans Retinoic Acid (ATRA) Sensitive and Resistant Acute Promyelocytic Leukemia Cells.
Authors: Khan Matiullah , Ng Angela Ping Ping , Jing Shen , Chen Chien-Shing , Ishii Shunsuke 
Published: April 2020

Abstract
PML, a suppresser of growth and proliferation in many cell types including hematopoetic cells, is localised to nuclear dot like structures known as PML oncogenic domains (POD). PML plays a crucial role in POD dependent and caspase 3 mediated apoptosis. PML-RAR, the causative agent of Acute Promyelocytic Leukaemia (APL), induces the disintegration of PODs, while Retinoid Acid (RA) mediated remission of APL is associated with reorganisation of PODs. These findings led to the concluation that disorganisation of POD is linked with the transforation of APL blasts. We have reported that nuclear hormon receptor co-repressor (N-CoR) is a component of PODs and is essential for PML mediated tumour suppressive function of Mad and Rb. (Khan MM et al. J Biol Chem.279:11814-24). Our most recent findings demonstrate that fusion protein PML-RAR triggers the ER stress and Unfolded Protein Response (UPR) by causing mis-folding and insoluble aggregation of N-CoR protein. (Khan MM et al. J Biol Chem.279:11814-24). These findings suggest that targeting the insoluble aggregation of N-CoR and the ER stress could represent an attractive therapeutic strategy for APL. Based on the hypothesis, we screened compounds known for their inhibitory effect on protein aggregation and ER stress. Among the compounds tested, genistein, a flavonoid, exhibited significant growth inhibitory effect on both RA sensitive and RA resistant APL cell NB4 in dose and time dependant manner (see fig.1 & 2). Genistein inhibited the growth on NB4 cells through collective effects on the cell cycle progression, apoptosis and differentiation. Genistein induced apoptosis in NB4 cells was mediated by the activation of caspase-3 and 9. Genistein also induced differentiation of NB4 cells as marked by appearance of cell surface differentiation marker CD11b. In cell cycle analysis, NB4 cells were accumulated in the G2-M phase after genistein treatment. In Western blotting assay, genistein unregulated and stabilized the level of PML protein in NB4 cells while promoting the degradation of PML-RAR. In protein solubility assay, genistein enhanced the solubility of N-CoR protein and reorganized the micro speckled like distribution of POD to normal dot like pattern in NB4 cells by immunocytochemical assay. In this study, we also identified that genistein abrogates PML-RAR mediated tyrosine phosphorylation of N-CoR protein. These findings, for the first time, have identified the therapeutic potential of genistein in both ATRA sensitive and resistant APL cells.
WP-1034, a Novel Jak-Stat Inhibitor, Has Proapoptotic and Antileukemic Activity in Acute Myeloid Leukemia (AML) Cell Lines and AML Patient Samples.
Authors: Faderl Stefan , Ferrajoli Alessandra , Harris David , Van Quin , Priebe Waldemar , Estrov Zeev 
Published: April 2020

Abstract
Proliferation and growth of AML cells result from stimulation by cytokines and high levels of cytokines are associated with poor prognosis in AML. Cytokines act through cellular receptors that are associated with members of the Jak family of protein tyrosine kinases. Upon phosphorylation and activation of Jak, proteins bound to Jak initiate signaling pathways including those regulated by Stat proteins. Since constitutive activation of Jak-Stat has been associated with leukemogenesis, we hypothesize that inhibition of Jak-Stat inhibits proliferation of AML cells. To do this, we studied the effects of WP-1034, a novel and potent inhibitor of Jak-Stat, in the OCIM2 AML cell line and fresh samples from AML patients. OCIM2 cells were deprived of serum for 2 hours and then incubated with 1 to 5 μM WP-1034 to investigate its effect on OCIM2 cell proliferation. After incubation of the cells without and with 1, 2.5, 5, 7.5, and 10 μM WP-1034 for 1 hour, and at 5 μM for 0, 20 min, 40 min, and 1, 2, 3, and 4 hours, we determined expression of Stat 1, 3, and 5, as well as Phospho-stat 1, 3, and 5 in the cells by Western Immunoblotting. In addition, we analyzed cell cycle status by PI staining and flow cytometry. We further evaluated induction of apoptosis of OCIM2 cells following incubation with WP-1034 at 3, 5, and 6 μM using the annexin V-CY5 assay and analyzed caspase 3 and PARP cleavage using Western Immunoblotting. To demonstrate the effect of WP-1034 on marrow cells from AML patients and healthy volunteers we incubated marrow cells with WP-1034 at increasing concentrations and used the blast colony assay to measure inhibition of proliferation. Our results show that: i) WP-1034 effectively inhibits proliferation of OCIM2 cells and AML blast proliferation from patient samples; ii) WP-1034 blocks activation of Stat 3 and 5 by decreasing the amount of Phospho-stat 3 and 5 in OCIM2 cells; iii) WP-1034 causes cell cycle arrest in sub-G0 phase and is able to induce apoptosis in OCIM2 cells; and iv) WP-1034 induces apoptosis involving cleavage of caspase 3 and PARP. Our data suggest that WP-1034, a potent inhibitor of Jak-Stat, inhibits proliferation of AML cells by inhibition of Stat 3 and 5 and induction of caspase-dependent apoptosis.
Inhibition of p53-MDM2 Interaction by Small-Molecule Antagonist of MDM2 Effectively Induces Apoptosis in Leukemias.
Authors: Kojima Kensuke , Konopleva Marina , Shikami Masato , Cabreira-Hansen Maria , Jackson C. Ellen , Shpall Elizabeth J. , Kornblau Steven M. , Vassilev Lubo T. , Andreeff Michael 
Published: April 2020

Abstract
Alteration of the p53 gene is one of the most frequent events in human tumorigenesis and about 50% of all solid tumors have been reported to carry p53 mutations. The inactivation of p53 in cancer has been associated with poor survival, refractory disease and chemoresistance. p53 mutations rarely occur in hematopoietic malignancies. Instead, MDM2 which is a principal cellular antagonist of p53, is overexpressed in the majority of leukemias. Recently, potent and selective small-molecule antagonists of MDM2, Nutlins, have been identified (Science303:844–888, 2004). Nutlins bind MDM2 in the p53-binding pocket and activate the p53 pathway in human cancer cells with wild-type p53, leading to cell cycle arrest, apoptosis, and growth inhibition of human tumor xenografts in nude mice. In this study, we investigated the potential antileukemic activity of the MDM2 antagonist. Treatment of wild-type p53 OCI-AML-3 cells with 5 μM of an active compound (Nutlin-3a) induced cell cycle arrest and apoptosis as evidenced by flow-cytometric analysis (51% reduction of S-phase at 12 h, 27% sub-G1 DNA content and 57% Annexin V positivity at 48 h). Similar proapoptotic effects were observed in MOLM-13 cells which have wild-type p53, but not in p53-null (HL-60 and U937) or mutant p53 (Raji, Jurkat and NB-4) cells. Nutlin-3a induced apoptosis in a dose- and time-dependent manner, and induced maximal effect on cell cycle arrest at 1 μM. Western blot analysis showed that in OCI-AML-3 cells, wild-type p53 accumulated at 1 h after exposure to Nutlin-3a. Increased levels of MDM2, p21 and Noxa proteins were observed at 1 to 3h. This resulted in cleavage of caspase-9 followed by cleavage of caspase-3. A pharmacologic interaction study between MDM2 inhibitor and Ara-C using a fixed-ratio (1:1) experimental design showed highly synergistic cell growth inhibition (CI = 0.44) and induction of apoptosis (CI = 0.83) in OCI-AML-3 cells. Initial studies conducted in primary leukemia cells demonstrated that Nutlin-3a induced apoptosis in 4 of 5 AML samples tested (68–97% Annexin V induction and 65–93% cell number reduction) and 2 CLL samples (&gt;50% Annexin V induction and 37% and 58% cell number reduction). Since MDM2 protein is overexpressed and p53 is not mutated in the majority of primary leukemia cells, this approach may have therapeutic utility in leukemias.
MLL-AF4 Down-Regulates CDKN1B (P27) Independent of Cell Cycle Progression.
Authors: Xia Zhenbiao , Popovic Relja , Lorenz Tara , Santillan Donna , Erfurth Frank , Zeleznik-Le Nancy J. 
Published: April 2020

Abstract
The MLL gene, involved in many chromosomal translocations associated with acute myeloid and lymphoid leukemia, has more than forty known partner genes with which it is able to form in- frame fusions. MLL fusion genes transform hematopoietic cells in vitro, and cause leukemia in mouse models. However, the mechanism is still not clear. Characterizing important downstream target genes may provide rational therapeutic strategies for the treatment of MLL-associated leukemia. We explored potential downstream target genes of the most prevalent MLL fusion protein, MLL-AF4, which is primarily associated with pro-B ALL and is involved in the majority of infant leukemia. To this end, we developed an inducible MLL-AF4 fusion cell line. Overexpression of MLL-AF4 does not lead to increased proliferation in this cell line, but rather, cell growth is slowed compared to similar cell lines inducibly expressing truncated MLL. To try to understand the reason for slower cell growth, we assayed for expression of several CDK inhibitors. We found that in the MLL-AF4 induced cell line, the amount of CDKN1B (cyclin-dependent kinase inhibitor P27) was dramatically decreased both at the RNA and protein levels, in contrast, the levels of CDKN1A (P21) and CDKN2A (P16) were unchanged. Interestingly, we did not observe an increased percentage of cells in S phase of the cell cycle. To explore whether CDKN1B might be a direct target of MLL-AF4, we employed chromatin immunoprecipitation (ChIP) assays and luciferase reporter gene assays. We observed that MLL-AF4 binds to the CDKN1B promoter in vivo and represses CDKN1B promoter activity. Further, we confirmed CDKN1B promoter binding by ChIP assays in the MLL-AF4 leukemia cell line MV4-11. Our results suggest that the CDKN1B may be a downstream target of MLL-AF4, and that MLL-AF4 inhibits CDKN1B expression independent of cell cycle progression.