bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Specificity and Isotype of Monoclonal Anti-D Antibodies Dictates Their Ability To Inhibit Opsonized Platelet Phagocytosis.
Authors: Semple John W. , Aslam Rukhsana , Kim Michael , Speck Edwin R. , Stewart Donald I.H. , Weirsma Erik , Freedman John , Kjaersgaard Mimi 
Published: October 2019

Abstract
The use of polyclonal anti-D is the established treatment for prophylaxis against rhesus immunization in Rh(D) negative pregnant women and is effective in raising the platelet counts in patients with autoimmune thrombocytopenic purpura (AITP). Since the supply of plasma derived anti-D antibodies is limited and plasma products carry the risk of infectious complications, replacement with monoclonal anti-D antibodies is a promising alternative. This study analyzed the efficacy of polyclonal anti-D (WinRho®SDF, Cangene) and six human monoclonal anti-D antibodies with differeing isotypes and specificities (Table 1) for their ability to opsonized erythrocytes and modulate monocyte phagocytosis of opsonized platelets in a flow cytometric assay. Human platelets were labeled with CellTracker CMGreen, opsonized with various HLA or HPA1a specific antibodies, incubated with the monocytic leukemic cell line THP-1 for 2 h and intracellular fluorescence was compared at 4°C and 37°C. Various concentrations of anti-D opsonized erythrocytes were added to the assay and the changes in intracellular fluorescence was compared. The results demonstrate that the THP cells significantly phagocytosed opsonized platelets in an Fc-dependent manner e.g. the fold change in median channel fluorescence between 37°C and 4°C for intact IgG W6/32 opsonized platelets was 51.5 ± 5.2 (mean+SD, n=74) and only 2.1+2.1 if the platelets were labeled with F(ab’)2 fragments. When erythrocytes were opsonized with the monoclonal anti-D antibodies that shared specificity but differed in IgG isotype (RhG1/RhG3 and BRAD3/BRAD5) and added to the assay, the IgG3 isotypes had a significantly greater ability to inhibit opsonized platelet phagocytosis compared with IgG1 isotypes and this inhibition was similar to that observed with polyclonal anti-D opsonized erythrocytes. However, in the one case where the monoclonal anti-D antibodies shared isotypes but differed in specificity (113/178), rRh9B8-113 monoclonal antibody significantly inhibited platelet phagocytosis whereas the rRh429-178 antibody did not. These results suggest that some human monoclonal antibodies can be as efficient as polyclonal anti-D in inhibiting opsonized platelet phagocytosis and the degree inhibition depends on the IgG isotype and specificity of the monoclonal antibodies. Thus, a defined cocktail of monoclonal anti-D antibodies could be prepared to mimic the effects and replace plasma-derived polyclonal anti-D.
Table 1: Characteristic of the monoclonal anti-D antibodies. Antibody Isotype Specificity rRh9B8-113 IgG1 Loop 3 rRh429-178 IgG1 Loop 4 RhG1 IgG1 Loop 6 RhG3 IgG3 Loop 6 BRAD3 IgG3 Loop 6 BRAD5 IgG1 Loop 6
The Geldanamycin Derivative DMAG Demonstrates Improved Cytotoxicity and Down-Modulation of Hsp90 Client Proteins Relative to 17-AAG in Chronic Lymphocytic Leukemia (CLL) Cells: Justification for Clinical Trials in CLL.
Authors: Johnson Amy J. , Wagner Amy J. , Smith Lisa L. , Lucas David M. , De Lay Michael D. , Allison Jamie M. , Ivy S. Percy , Lin Thomas S. , Byrd John C. 
Published: October 2019

Abstract
The heat shock protein Hsp90 functions to stabilize important cell survival- and proliferation-related kinases such as AKT, IKK, c-Src, Raf-1, and cdk9. Cancer cells have activated Hsp90 as compared to normal cells, making this a relevant therapeutic target to eliminate these kinases. The semi-synthetic geldanamycin derivative 17-allylamino-17-demethoxygeldanamycin (17-AAG) binds to and inhibits the activity of Hsp90, and previous work demonstrated the ability of 17-AAG to deplete AKT in several cancer types in vitro. A newer geldanamycin derivative, 17-(dimethylaminoethylamino)-17-demethoxygeldanamycin (DMAG) has improved pharmacological properties including solubility and oral bioavailability, and was shown to be more effective than 17-AAG in melanoma and pancreatic carcinoma mouse xenograft mouse models. We therefore examined the effects of 17-AAG and DMAG against CD19-positive tumor cells from CLL patients. Cell viability was examined by the MTT assay, and AKT and IKK protein expression was examined by immunoblot analysis. In samples from seven CLL patients, 1.0uM DMAG resulted in 31.5% viability (95% CI: 13.1–50.0%), compared to 61.5% viability (95% CI: 45.0–78.0%) using the same concentration of 17-AAG. In four CLL patient samples treated with 1.0uM DMAG for 24 hours, AKT was decreased an average of 72.5% (95% CI: 57.7–87.3%) relative to the untreated controls. This is in comparison to 1.0uM 17-AAG, which caused a 52.7% decrease in AKT (95%CI: 39.7–65.6%). IKK protein was also decreased at similar levels in all patient samples examined. This data indicates that in CLL cells, DMAG has superior activity both in cytotoxicity and in reduction of relevant Hsp90 client proteins. 17-AAG is currently undergoing Phase I clinical testing in CLL, and DMAG is completing phase I clinical development in solid tumor malignancies. Overall, our data and that of others support clinical development of DMAG in CLL, based on the improved pharmacologic properties, enhanced efficacy relative to 17-AAG, and expected down-regulation of target proteins. In addition, our in vitro observations support using measurement of protein down-regulation of AKT and IKK as pharmacodynamic biomarkers of activity in patients undergoing therapy with these agents.
Attacking Oncogene Addiction in B-CLL: Seliciclib First Engages the Mcl-1/Noxa Axis, after Which Gradual Exhaustion of Bcl-2 Protection Leads to Bax Activation.
Authors: Hallaert Delfine Y.H. , Spijker Rene , Jak Margot , Jaspers Annelieke , Derks Ingrid A.M. , Alves Nuno L. , de Boer Jan Paul , de Jong Daphne , Green Simon R. , van Lier Rene A.W. , van Oers Marinus H.J. , Eldering Eric 
Published: October 2019

Abstract
Background : Seliciclib (R-roscovitine) is a cyclin-dependent kinase inhibitor in clinical development. It triggers apoptosis by inhibiting de novo transcription of the short-lived anti-apoptotic Mcl-1 protein, but it is unclear if and how this leads to Bax or Bak activation that is required for most forms of cell death.
Aim: To study the effects of seliciclib on apoptosis gene expression and Mcl-1 and Bcl-2 protein interactions in B cell chronic lymphocytic leukemia (B-CLL), a malignancy with known aberrant apoptosis regulation.
Methods: Purified B-CLL cells (PBMC consisting of >90% B-CLL cells; n=20) and Ramos cell lines overexpressing different apoptosis regulators were used in this study. The effect of seliciclib on viability, apoptosis gene expression pattern, and protein associations was investigated via RT-Multiplex-Ligation-dependent Probe Amplification (RT-MLPA), Western blotting and co-immunoprecipitation assays. Ramos cells were transduced with retroviral vectors expressing either Noxa siRNA, Bim siRNA or control-GFP virus, and tested for different apoptosis stimuli.
Results: We found that although seliciclib resulted in proteasome-dependent Mcl-1 degradation within 4 hrs in B-CLL cells, Bax and Bak activation and apoptosis occurred with a considerable delay, i.e. at 16 hrs. During this period, there was no evidence of transcriptional changes in p53-responsive or apoptosis-related genes. In freshly isolated, viable B-CLL cells, pro-survival Mcl-1 was engaged by the pro-apoptotic proteins Noxa and Bim but not by Bak. The contribution of Noxa [Figure1] and Bim (liberated from McL-1 within 4 hours) as specific mediators of seliciclib-induced apoptosis was demonstrated via RNAi in two model systems. Interestingly, 16 hrs after seliciclib treatment, there was a clear accumulation of Bcl-2, Bim, and Bax in the detergent insoluble (mitochondria containing) fraction of B-CLL cells. This suggests that after Mcl-1 degradation, the remaining apoptosis neutralizing capacity of Bcl-2 is gradually overwhelmed, probably resulting in Bax multimerisation and pore formation in the mitochondria.
Conclusions: These data support the ’oncogene-addiction’ model in which malignant cells depend on increased Bcl-2 levels, and extend it to include Mcl-1. Furthermore, since Noxa is elevated in B-CLL, its involvement in p53-independent apoptosis suggests this BH3-only protein may be a therapeutic target.
Figure Figure
Deletions of the Derivative Chromosome 9 Do Not Influence Response to Imatinib of Early Chronic Phase Chronic Myeloid Leukemia Patients (A GIMEMA Working Party Analysis).
Authors: Castagnetti Fausto , Marzocchi Giulia , Luatti Simona , Buontempo Francesca , Baldazzi Carmen , Palandri Francesca , Giannoulia Panagiota , Amabile Marilina , Iacobucci Ilaria , Mancini Marco , Giussani Ursula , Specchia Giorgina , Cuneo Antonio , Gugliano Emilia , Kerim Simonetta , Modaferri Bruno , Abruzzese Elisabetta , Martinelli Giovanni , Testoni Nicoletta , Rosti Gianantonio , Baccarani Michele 
Published: October 2019

Abstract
Extensive submicroscopic deletions adjacent to the breakpoint on derivative chromosome 9 [der(9)] have been reported in a subset of Chronic Myeloyd Leukemia (CML) patients and have been associated with an adverse outcome with conventional drugs and α-interferon (α-IFN). Huntly et al (Blood.2003; 102.2205–12) reported 275 CML pts who were treated with imatinib in CP, suggesting that der(9) deletions were associated with lower response rates and a shorter time to progression. Different data were reported by Quintas-Cardama et al (Blood.2005; 105:2281–6), who did not find any difference related with der(9) deletions in other 320 patients treated with imatinib. In these 2 studies, some patients began imatinib in early CP (51 and 152, respectively) while many patients (224 and 168, respectively) were treated in late CP. To establish the relationship of der(9) deletions with the response to imatinib in early CP patients, we planned a prospective study involving 3 consecutive multicentric national studies of the GIMEMA (Gruppo Italiano Malattie Ematologiche dell’Adulto) CML Working Party. 421 CML patients in early chronic phase were enrolled between January, 2004 and January, 2006; Fluorescence in situ hybridization (FISH) analysis of bone marrow cells was performed using BCR/ABL extra-signal, D-FISH or dual-color dual-fusion probes. At diagnosis, 52 (12%) of them had der(9) deletion and 369 (88%) had not. The 2 groups, with/without deletions, were comparable (no difference in age, Sokal risk, imatinib dose). Median observation time is 12 months. At 3 months, the CHR rates in with/without deletions patients were 87%/92%. At 6 months, the complete cytogenetic response (0% Ph-pos; CCgR) rates were 80%/80%, with major molecular response (MMolR, defined as a Bcr-Abl/Abl x 100 ratio < 0.1%) rates of 52%/51%, respectively. At 12 months, CCgR rates were 89%/86% and MMolR 52%/61%. No difference is significant. We conclude that the presence of der(9) deletions at diagnosis do not constitute a negative factor for response to imatinib: the haematological, cytogenetic and molecular response rates resulted equal between the 2 groups of patients with and without der(9) deletions. This finding is relevant to the long term effect of imatinib treatment, since both the CCgR and the MMolR are important and established indicator of long term survival.
Extracellular Signal-Regulated Protein Kinase 5 Mediates Resistance of Human Chronic Myeloid Leukemia K562 Cells to Imatinib.
Authors: Sovershaev Mikhail A. , Egorina Elena M. , Gruber Franz X. , Bjørkøy Geir , Johansen Terje 
Published: October 2019

Abstract
Mutations in the Abl kinase domain and Bcr-Abl gene amplification have been recognised as the most common mechanisms of resistance to Imatinib (Gleevec) in chronic myeloid leukemia (CML). However, Imatinib resistance by Bcr-Abl independent mechanisms have also been reported. The extracellular signal-regulated protein kinase 5 (Erk5) signalling pathway is involved in cell survival and cell cycle control functions. Interestingly, it was recently reported that ERK5 is important in CML (Buschbeck M., 2005). Bcr/Abl was found to increase the level of Erk5 by stabilizing the protein thus contributing to increased cell survival. In this study we asked whether small interfering RNA (siRNA)-mediated depletion of endogenous Erk5 or overexpression of wild type Erk5 would affect the survival of Imatinib-treated human K562 CML cells. These cells express Bcr-Abl with a wild type kinase domain. Fluorescence activated cell sorting analyses of propidium iodide-stained K562 cells revealed that treatment with 1 μM Imatinib for 24 hrs led to an increase of the apoptotic cell population from 9 to 27 %. The number of cells, arrested in G0/1 phase was also elevated following Imatinib treatment from 66 to 85 %. Overexpression of wild type Erk5 in K562 cells reduced the frequency of Imatinib-induced apoptosis from 27 to 18 % without affecting cell cycle distribution of the living cells. After having established that overexpression of Erk5 renders cells partially resistant to Imatinib treatment we tested the effect of siRNA-mediated depletion of endogenous Erk5 on the viability of K562 cells challenged with Imatinib. Indeed, 42% of K562 cells transfected with siRNA against Erk5 underwent apoptosis after Imatinib treatment. Imatinib induced apoptosis in only 20% of cells transfected with a control siRNA. Furthermore, Erk5 depletion strongly inhibited cell cycle progression in Imatinib-treated K562 cells. Thus, the cell populations in S phase and mitosis were reduced from 22 to 16 % and from 24 to 9 %, respectively. Taken together, our data and those of Buschbeck et al. suggest that ERK5 levels may strongly affect cell survival during Imatinib treatment of CML cells.
First Overall Molecular Response of the Randomized French SPIRIT Study on Behalf the Fi-LMC Group.
Authors: Roche-Lestienne Catherine , Mahon François-Xavier , Crinquette Antoine , Guilhot Joëlle , Guilhot Francois , Preudhomme Claude 
Published: October 2019

Abstract
In September 2003, the French CML study group (Fi-LMC) activated the four armed randomized SPIRIT trial comparing imatinib 400mg with imatinib 600mg, imatinib 400mg + ara-C and imatinib 400mg + pegylated interferon in newly diagnosed CML in chronic phase. The molecular monitoring was centralized and performed, according to the EAC protocol, in duplicate on the same BCR-ABL cDNA among two French laboratories (Bordeaux and Lille). Data were expressed as BCR-ABL/ABLx100 on the new internationally agreed scale (IS) using a conversion factor of 1.33 and 0.80 for Bordeaux and Lille respectively. A good correlation between the two laboratories was observed. During the first year of follow-up the quantification was performed each three months (M0 to M12). In May 2006, 297 of the 492 enrolled pts had a follow up of more than 12 months, and 263 pts were analysed at M12. Using the IS, the median values of the BCR-ABL/ABL normalized ratios were 90%, 6,4%, 0.68%, 0.32% and 0.16% at M0, M3, M6, M9, and M12 respectively. At M12, 15%, 29%, 27%, 17% and 12% of the pts presented a BCR-ABL/ABL ratio lower than 0.01%, 0.1%, 1%, 10%, and 100% respectively. Overall, 44% of the pts reached the Major Molecular Response (MMR). Results were also expressed using individual M12/M0 ratio. At M12 13%, 29%, 28%, 17% and 13% of the pts presented a 4 log, 3 log, 2 log, 1 log and 0 log reduction respectively. Overall, 42% of the pts presented an individual 3 log reduction.
Despite very similar results between the two means of expression, the pts distribution was different due to unlike individual BCR-ABL transcript level at MO. Furthermore, the analysis of 75 paired samples before (at diagnosis) and after (at inclusion) hydroxyurea treatment (5 days to 1.2 months) revealed BCR-ABL/ABL ratios of 129% and 108% respectively, confirming the 0.2 log difference previously reported by A. Hochhaus et al.
In conclusion, expression of the data using the new IS or the individual M12/M0 ratio was very similar in our experience regarding the percentage of each subgroup but the pts distribution was different and a longer follow up would be useful to define the best method. However, the good correlation observed in the IRIS trial between MMR and progression, the influence of hydroxyurea treatment on BCR-ABL level, the good correlation observed among laboratories and the need of harmonisation of expressed results influenced our choice for the new IS. The application of this recommendation is in progress in the great majority of the molecular French laboratories.
Sokal and Hasford Scores Are Able To Predict Cytogenetic Response and Survival in CML Patients Who Failed Prior Therapy and Are Receiving Salvage Therapy with Imatinib or Other Tyrosine Kinase Inhibitors.
Authors: Tam Constantine S. , Kantarjian Hagop M. , Shan Jenny , Wierda William G. , Ferrajoli Alessandra , Koller Charles Asa , Cortes Jorge 
Published: October 2019

Abstract
Sokal and Hasford scores have been used to estimate the survival of CML patients following alkylator-based or interferon-based therapy, and may also predict the outcome of patients receiving first-line imatinib. These scores were designed for patient characteristics at the time of diagnosis and they have been assumed to have no clinical value at other times during the course of the disease (eg. second-line or subsequent therapy). We seek to determine the applicability of the Sokal and Hasford scores in predicting outcomes in patients receiving second or subsequent-line therapy with imatinib and other novel tyrosine kinase inhibitors (TKI). This analysis is based on 379 CML patients in chronic phase (90%) or accelerated phase as defined by cytogenetic clonal evolution (10%), who were enrolled on clinical trials of imatinib following interferon failure (n=294), or nilotinib or dasatinib following imatinib failure (n=85). Significance of relationship between Sokal and Hasford risk categories and response were tested using the Chi-Square test, and differences in survival assessed using the log-rank method. P-values are summarised below:
Imatinib following Interferon Failure Nilotinib/Dasatinib Following Imatinib Failure Sokal Hasford Sokal Hasford *comparison between low and intermediate risk groups only Low Risk 219 (74%) 176 (60%) 39 (46%) 45 (53%) Intermediate Risk 65 (22%) 111 (38%) 34 (40%) 38 (45%) High Risk 10 (3%) 6 (2%) 12 (14%) 2 (2%) Any Cytogenetic Response p<0.001 p<0.001 p=0.01 p=NS Major Cytogenetic Response p<0.001 p<0.001 p=0.002 p=0.04* Complete Cytogenetic Response p<0.001 p<0.001 p=0.005 p=0.07* Survival p<0.0001 p<0.0001 Insuff Events Insuff Events
Among patients receiving imatinib following failure of interferon therapy, both Sokal and Hasford scores were highly predictive of cytogenetic response and overall survival. Due to the low number of deaths (n=5) on the nilotinib and dasatinib trials, the effect of Sokal and Hasford scores on predicting survival could not be assessed but they remain predictive of cytogenetic response. We conclude that the Sokal and Hasford scores calculated at the time of therapy failure are useful predictors of subsequent response to salvage therapy with imatinib and other TKIs.
A Phase II Study of Nilotinib, a Novel Tyrosine Kinase Inhibitor Administered to Patients with Imatinib Resistant or Intolerant Chronic Myelogenous Leukemia (CML) in Chronic Phase (CP), Accelerated Phase (AP) or Blast Crisis (BC) Who Have Also Failed Dasatinib Therapy.
Authors: Giles Francis , le Coutre Philipp , Bhalla Kapil , Rosti Gianantonio , Ossenkopplele G.J. , Alimena Giuliana , Weitzman Aaron , Rafferty Teresa , Zheng Ming , Kantarjian Hagop 
Published: October 2019

Abstract
Nilotinib is a potent, highly selective, aminopyrimidine inhibitor which in vitro is 30-fold more potent than imatinib and active against 32/33 imatinib resistant cell lines with Bcr-Abl mutations. This open-label study was designed to evaluate the efficacy and safety as defined by hematologic and cytogenetic response rates (HR/CyR) of nilotinib administered at a daily dose of 400 mg bid to patients who previously received and either failed or were intolerant to imatinib and dasatinib. A total of 50 patients were enrolled and included CP (n=26), AP (n=10), and BC (n=14) patients. Of the 14 BC patients 10 were myeloid and 4 were lymphoid. Overall 8 (16%) patients had extramedullary disease at baseline. The median age was 57 (range 19–78) years and the median time from first diagnosis of CP, AP, or BC to treatment was 65 (range 8–213) months. The median duration of nilotinib exposure was 226 (range 3–379) days. A total of 28 (56%) patients remain on treatment, 22 (44%) discontinued (6 for adverse events, 11 for disease progression, 3 withdrew consent, and there were 2 deaths related to cerebral hemorrhages). Complete (HR) was reported in 9 of the 20 (45%) CP patients who did not have a CHR at baseline. Of the 26 CP patients, 8 (31%) had a major CyR (2 complete and 6 partial), 2 (8%) patients had minimal responses, and 9 (35%) patients had no response. Disease progression occurred in one CP patient and 6 patients were not evaluable. Confirmed hematologic responses were observed in 2 of 10 (20%) AP patients who had a return to chronic phase (RTC), 7 patients were not evaluable and there was one patient death. Of the 10 AP patients 1 (10%) each had CyR (partial, minor, minimal and no response). Of the 14 BC patients 1 had a CHR (7%), 2 (14%) had a return to chronic phase (RTC), 6 (43%) were not assessable for response, and 5 (36%) had progressive disease. Overall the most frequent Grade 3 or 4 adverse events reported were thrombocytopenia in 12 (24%), neutropenia in 11 (22%), and anemia in 5 (10%) patient. In summary, nilotinib has significant clinical activity and an acceptable safety and tolerability in CML-CP, AP, and BC patients who were resistant or intolerant to imatinib and have also failed dasatinib therapy.