julilili42/papers huggingface dataset:
Iron Containing Nucleosides as New Cytostatic Substances for Cancer and Leukemia Therapy, Especially for Therapy of Relapsed ALL in Childhoodtransfusion of Red Blood Cells under Shock Conditions in the Rat Microvasculature.
2004-11-16

Abstract Acute lymphoblastic leukemia (ALL) is the most common malignant disease in childhood. Despite a relatively good prognosis approximately one fourth of the patients suffers from relapse and, consequently, a worse prognosis. Only 40 % of these children with relapsed ALL will survive. Patients who fail to achieve a complete remission in chemotherapy do not survive. This explains the need for new compounds that may overcome resistance against clinically employed cytostatic drugs. Here we describe a new class of iron-containing nucleosides that overcome drug resistance in vitro and ex vivo. Analyses of apoptosis induction in primary lymphoblasts from 30 children with de novo ALL and relapsed ALL showed that these iron-containing nucleoside analogs are far more potent as compared with conventional nucleoside analogs employed in clinical therapy of childhood ALL (cytosinarabinoside: p &lt; 0.0064). Furthermore we demonstrate ex vivo these novel nucleoside analogs overcome drug resistance against fludarabine (p&lt;0.0162) and doxorubicin (p&lt;0.002). Additional experiments revealed that the prototype of iron-containing nucleoside analogs, N69, specifically induced apoptosis, as evidenced by DNA fragmentation, dissipation of the mitochondrial membrane potential and activation of caspase-3. All those events occurred in the absence of cellular lysis, i. e. in the absence of release of lactate dehydrogenase from the cells, thereby excluding N69-induced necrosis. N69-induced cell death was functionally characterized by the use of different cellular model systems being devoid of defined molecular parts of the apoptosis machinery. According to those results, the CD95-dependent apoptosis cascade is not involved in N69-induced cell death. Furthermore, N69 triggers apoptosis in a Bax-independent manner in the essentially Bax-free prostata carcinoma cell line DU145. Thus, N69 is able to break the Bax-related drug resistance that plays an important role in the therapy of relapsed ALL in childhood. In addition, we could show that N69-induced apoptosis even proceeds in the absence of caspase-3 expression. We demonstrate here that N69 still exerts a considerable apoptosis-inducing effect in the caspase-3-deficient, multi drug-resistant (i. e. taxol-, epirubicin- and etoposide-resistant) mamma carcinoma cell line MCF-7. Taken together, iron-containing nucleosides comprise a totally new, very promising class of cytostatic agents for cancer and leukemia therapy, especially for the therapy of relapsed ALL in childhood. Future studies will aim to elucidate the target structures of these new compounds and to demonstrate N69-mediated anti-cancer activity in vivo. First experiments in mice show a good tolerability of N69.
Treatment of Adult Patients with High Risk Acute Myeloblastic Leukemia up to 60 Years: Role of Consolidation Therapy within a Prospective Multicenter Trial.
2004-11-16

Abstract In our prospective multicenter AML 01/99 trial for risk-adapted therapy of patients aged up to 60 years with acute myeloblastic leukemia, patients with CBF-leukemias [t(8;21) or inv(16)] or normal karyotype and good response (GR) to induction I (up to 5% blasts in day 15 BM) were considered standard risk (SR), all other patients as high risk (HR). Patients with acute promyelocytic leukemia were excluded. Between January 1999 and May 2004, 421 patients (328 with with de novo and 93 with secondary AML) were treated. Induction course I consisted of standard dose araC, idarubicine and etoposide (IVA-I). Patients with GR to IVA-I continued with IVA-II on day 21 as double induction. In patients with bad response (&gt;5% bone marrow blasts on day 15), the second cycle consisted of either IVA-II or FlAG/Ida. Double induction was followed by an early consolidation with intermediate dose araC. As late consolidation, HR patients were allo- [HLA-matched sibling or matched unrelated donor (MUD)] or autotransplanted. Matched sibling allotransplantation was done in all participating centers whereas MUD transplantation was favoured by only two centers. The remaining centers performed autologous PBSCT if there was no sibling donor available. 199 patients were classified as HR, of whom 118 (59%) achieved CR, and 25 (13%) of the HR patients died during induction. After 55 months, overall survival was significantly worse for HR patients (25%) than for SR patients (49%). This was also true for the relapse-free survival (32% vs. 42%; p = 0.049). In the HR group, there was no difference in overall and relapse-free survival between those patients classified as HR because of bad response to IVA-1 (n = 65), unfavourable karyotype (n = 71) or both characteristics (n = 63). Regarding the different regimens for late consolidation, the “as treated” analysis of the HR patients revealed that overall (59% vs. 20%) and relapse-free survival (59% vs. 20%) was significantly better after an allogeneic HLA-matched sibling transplantation (n = 26) than after autoPBSCT (n=24). Overall and relapse-free survival for the 23 patients who underwent MUD transplantation were 59% and 45% respectively. In conclusion, in HR patients with an HLA-identical sibling donor an allotransplantation should be performed. The results obtained with MUD transplantation in this particular patient group are encouraging. Therefore, in HR patients without an HLA-identical sibling allografting from unrelated donors should be considered in first CR. On the other hand, HR patients as defined by our risk stratification do not seem to benefit from autografting even after intensive induction and consolidation therapy.
BMS-354825 Potently Inhibits the Kinase Activity of KIT Activation Loop Mutations Associated with Systemic Mastocytosis and Induces Apoptosis of Mastocytosis Cell Lines.
2004-11-16

Abstract Activating mutations of the activation loop (AL) of KIT are reported in several human neoplasms including a subset of patients with AML or systemic mast cell disorders. The small molecule tyrosine kinase inhibitor, imatinib, is a potent inhibitor of wild type KIT and certain mutant KIT isoforms and has become the standard of care for treating patients with metastatic GI stromal tumors. However, KIT AL mutations such as D816V that are typically found in AML and systemic mast cell disease are insensitive to imatinib (IC50 &amp;gt; 5–10 micromolar). In addition, acquired AL mutations are associated with imatinib resistance in GI stromal tumors. Experimental models of these diseases suggests that targeted inhibition of AL-mutant KIT in such cells would result in decreased proliferation and induction of apoptosis. BMS-354825 is a synthetic small-molecule ATP-competitive inhibitor of SRC and ABL tyrosine kinases with potency in the low nanomoloar range. In addition, BMS-354825 also inhibits many of the acquired BCR-ABL mutations associated with imatinib-resistant CML. Notably, BMS-354825 binds to the ATP-binding site in ABL regardless of the conformation of the AL and is therefore able to potently inhibit the kinase activity of AL-mutants of BCR-ABL. BMS-354825 is currently being tested in phase I studies for safety and efficacy in the treatment of imatinib-resistant CML as well as for various solid tumors. We investigated the inhibitory potential of BMS-354825 against KIT AL-mutants expressed by different mastocytosis/mast cell leukemia cell lines. We first examined the activity of BMS-354825 against the kinase activity of wild-type KIT kinase expressed by M07e cells. BMS-354825 potently inhibited the kinase activity of SLF-dependent M07E cells with an IC50 of 1–10 nM for autophosphorylation and cellular proliferation. In contrast, the IC50 for inhibition of GM-CSF-dependent proliferation was ~5 micromolar. BMS-354825 also potently inhibited the proliferation of the human mast cell leukemia cell line HMC-1 that expresses a juxtamembrane KIT V560G mutant kinase (IC50 1–10 nM). Notably, BMS-354825 inhibited autophosphorylation of KIT D816V with an IC50 of ~100 nM. Similar potency for inhibition of proliferation and induction of apoptosis (IC50 150–400 nM) was seen using three different cell lines expressing human D816V or the homologous murine D814Y KIT kinase. We conclude that BMS-354825 potently inhibits the kinase activity of wild-type KIT and imatinib-resistant KIT AL-mutant kinases associated with AML and systemic mast cell disorders. If BMS-354825 proves to be safe and tolerable in ongoing phase I trials, it should be further tested in clinical studies targeting patients with human malignancies associated with imatinib-resistant KIT AL-mutations.
Late Consolidation for Patients with Standard Risk AML up to 60 Years: Results of a Prospective Randomized Comparison of High Dose AraC and Autologous PBSCT.
2004-11-16

Abstract 421 patients (pts.) up to 60 years with de novo (n=328) or secondary (n=93) AML were treated with risk-adapted therapy. Pts. with CBF-leukemias [t(8;21) or inv(16)] or normal karyotype and good response (GR) to induction I (up to 5% blasts in day 15 BM) were considered standard risk (SR), all others as high risk (HR). Induction I consisted of standard dose araC, idarubicine and VP16 (IVA-I). Pts. with GR to IVA-I continued with IVA-II on day 21. In pts. with bad response, the second cycle consisted of either IVA-II or FlAG/Ida. Double induction was followed by early consolidation with intermediate dose araC. As late consolidation, SR patients were randomized between high dose (HD) araC (12 x 3g/m2)/daunorubicine (3 x 45mg/m2) or an autologous PBSCT with PBSC mobilized after early consolidation except SR pts. with normal karyotype and an HLA-matched sibling who were allotransplanted. 214 pts. were classified as SR and 199 as HR. 91% of the SR and 59% of the HR pts. achieved CR (overall CR rate 75%) and 1% of the SR pts. died during induction. After 55 months, overall survival was significantly better for SR (49%) than for HR pts. (25%). Within the SR group, relapse free survival at 46 months was 63% for 21 pts. with inv(16), 58% for 25 pts. with t(8;21), and 37% for 148 pts. with normal karyotype (p = 0.13). Overall survival at 48 months was significantly better (p=0.014) for pts. with inv(16) (93%) than for those with t(8;21) (60%) or normal karyotype (44%). 48 SR pts. (12 with CBF leukemia) were randomized to receive HDaraC and 53 (14 with CBF leukemia) to undergo autoPBSCT. At 55 months, the overall survival was 52% for the autotransplanted pts. and 65% for those receiving HDaraC (p=0.71, intent-to-treat analysis). Median duration of neutropenia (&lt;500/ μl) was 8 days for autoPBSCT and 19 days for HDaraC. Eleven pts. died in the HDaraC group (4 in CR and 7 from relapse) and 12 autotransplanted pts. died (1 in CR and 11 from relaspe). In pts. with normal karyotype, overall survival at 55 months for the allotransplanted SR pts. (n = 29) was 58% with no significant difference to HDaraC (62%) or autoPBSCT (43%). Relapse free survival for SR pts. with normal karyotype was 56% after allotransplantation, and 36% after autoPBSCT and HDaraC respectively (p = n.s.). In conclusion, overall survival is similar in SR AML pts. after autoPBSCT, HDaraC or allotransplantation. In SR pts. without an HLA-identical sibling donor, the reduced treatment related toxicity recommends autoPBSCT as late consolidation. In standard risk pts. with normal karyotype, allotransplantation from an HLA-identical sibling seems to have the highest antileukemic activity.
c-kit D816V Provides a Strong Signal for Myelomastocytic Differentiation and Cluster Formation in Murine Ba/F3 Cells.
2004-11-16

Abstract The pathologic hallmark of systemic mastocytosis (SM) is differentiation and cluster formation of mast cells (MC) in hematopoietic tissues. The somatic c-kit mutation D816V is detectable in a majority of all SM patients independent of the proliferation-status of MC or subtype (indolent or aggressive) of disease. To investigate the role of c-kit D816V in the pathogenesis of SM, we established a Ba/F3 cell line with doxycycline-inducible expression of c-kit D816V. We found that c-kit D816V provides a strong signal for mast cell differentiation and cluster formation in Ba/F3 hematopoietic progenitor cells without enhancing their growth thereby resembling the clinical presentation of indolent SM (ISM). As assessed by gene chip analysis, induction of c-kit D816V resulted in expression of various differentiation antigens including mouse mast cell protease 5, mi transcription factor, histidine decarboxylase (HDC), secretory granule proteoglycan, IL-4 receptor, ICAM-1, and CD63 consistent with an early phase of mastopoiesis. By contrast, c-kit D816V did neither induce expression of granulo-monocytic antigens such as myeloperoxidase, IL-3 receptor, or GM-CSF receptor, nor expression of ‘late stage’ mast cell antigens such as FcεRI. The c-kit D816V-induced synthesis of histamine in Ba/F3 cells was confirmed by RIA. To examine the role of c-kit D816V in the pathogenesis of mastocytosis, we extended our analysis to bone marrow biopsy sections obtained from patients with ISM. In these experiments, the D816V-mutated form of c-kit was detected more frequently in micro-dissected tryptase-positive MC obtained from dense compact infiltrates (44.2%) than in diffusely spread MC in these patients (22.6%) (p&amp;lt;0.05). In summary, our data establish a role for c-kit D816V in differentiation and cluster formation of neoplastic (mast) cells. Additional genetic hits, apart from c-kit D816V, may be responsible for aggressive growth of MC in advanced MC neoplasms.
Genetic and Functional Characterization of Isolated Stromal Cell Lines from the Aorta-Gonado-Mesonephros (AGM)-Region.
2004-11-16

Abstract The aorta-gonads-mesonephros (AGM) region autonomously generates adult repopulating hematopoietic stem cells (HSC) in the mouse embryo and provides its own HSC-supportive microenvironment. Stromal cells from adult bone marrow, yolk sac, fetal liver and AGM have been used in coculture systems for analysing growth, maintenance and differentiation of hematopoietic stem cells. We generated &amp;gt;100 cloned stromal cell lines from the AGM of 10.5 dpc mouse embryos. In previous studies, we tested these for support of murine adult and human cord blood (CB) CD34+ cells. We could demonstrate that 25 clones were superior to the MS5 bone marrow stromal cell line in supporting progenitor cell expansion of adult mouse bone marrow both, in 2ndry CFC and CAFC production. In addition we demonstrated that 5 AGM lines promoted in absence of exogenous growth factors the expansion of human CB cells with progenitor (CFC production for at least 5 weeks) and stem cell (repopulation of cocultured cells in NOD/SCID assay) function. Now, we could show that one of the isolated stromal cell lines (AGM-S62) is capable in differentiating undifferentiated murine embryonic stem (mES) cells into cells of the hematopoietic lineage. A sequential coculture of mES-cells with AGM-S62 showed production of CD41+ hematopoietic progenitor cells at day 10 as well as 2ndry CFC and CAFC production of day 10 suspension cells. Hematopoietic cell differentiation was comparable to standard OP9 differentiation assay. With these data, we can describe for the first time, that a stromal cell line other than OP9 can induce hematopoietic differentiation of undifferentiated mES cells. Hematopoietic support occurs independently of M-CSF deficiency, which is the characteristic of OP9 cells, because it is strongly expressed by AGM-S62. To evaluate genes responsible for hematopoietic cell support, we compared a supporting and a non-supporting AGM stromal cell line by microarray analysis. The cell line with hematopoietic support clearly showed a high expression of mesenchymal markers (laminins, thrombospondin-1) as well as characteristic genes for the early vascular smooth muscle phenotype (Eda). Both phenotypes are described for stromal cells with hematopoietic support generated from bone marrow and fetal liver. In addition, the analysed supporting AGM stromal cell line interestingly expressed genes important in early B-cell differentiation (osteoprotegerin, early B-cell factor 1, B-cell stimulating factor 3), which goes in line with data demonstrating early B-cell development in the AGM-region before etablishing of fetal liver hematopoiesis. Further studies will show the significance of single factors found to be expressed in microarray analyses. This unique source of &amp;gt; 100 various cell lines will be of value in elucidating the molecular mechanisms regulating embryonic and adult hematopoiesis in mouse and man.
Activation of Monocytes by Aspergillus Fumigatus Hyphae and Conidia.
2004-11-16

Abstract Invasive aspergillosis is a life-threatening infection in immunocompromised patients. Activation of innate immune cells is crucial for the successful control of invasive aspergillosis. Monocytes play an important role in the cellular defense against Aspergillus fumigatus by attacking defined differentiation states of the fungus and by the release of pro-inflammatory cytokines and chemokines. In order to get a better understanding on pathways involved in these defense mechanism, genome-wide expression profiling was performed after incubation of CD14+ selected monocytes with A. fumigatus conidia and hyphae for 3, 6 and 9 hours using the Affymetrix HG-U133A array. Moreover, phagocytosis of conidia was analyzed by immunofluorescence. Expression of defined cytokines and chemokines was confirmed by Real-time PCR and on protein level by ELISA. Phagocytosis of conidia was observed during the first 3 hours (up to 2–3 conidia/monocyte). The conidia became swollen after 6 hours. By genome-wide expression profiling, ~600 genes were differentially regulated after 3 hours of incubation with hyphae and ~200 after incubation with conidia. At 6 and 9 hours of incubation, the number of differentially regulated genes showed no difference (~400 genes by both stimuli). Hyphae but not conidia strongly induced the expression of chemokines attracting neutrophils and T-lymphocytes as well as their receptors already after 3 hours, indicating that phagocytosis of conidia does not immediately induce expression of inflammatory genes. Pentraxin-3 was upregulated after 3 but not after 6 hours by both conidia and hyphae. PTX-3 binds to A. fumigatus and plays a role in initiating phagocytosis. Genes encoding for inflammatory cytokines and chemokines as well as their receptors were found to be up-regulated at 6 and 9 hours by both stimuli. Urokinase plasminogen activator (uPA), which plays an essential role in regulating fibrinolysis and thereby monocyte/macrophage recruitment to sites of inflammation, was also found to be upregulated after stimulation with both stimuli. ELISA experiments confirmed these results on protein level, demonstrating a steady increase of chemokine and cytokine concentrations in culture supernatants from 3 to 9 hours. In conclusion, A. fumigatus differentially regulates a wide number of genes expressed by human monocytes, which play a crucial role in immune response during infection. The expression of these genes is dependent on the differentiation and germination state of the fungus and the incubation period.
Chronic Myeloid Leukemia (CML) in Childhood - Results of the Multicenter-Trial CML-paed.
2004-11-16

Abstract CML is a rare disease in childhood and hematopoietic stem cell transplantation (SCT) remains the only proven option for cure of young patients (pts). We here report the results of the GPOH-trial “CML-paed”. From December 1995 to June 2004 pts younger than 19 years (median age: 11.4 yrs) with Philadelphia-chromosome positive CML (n=193; 99 boys, 94 girls) were treated by hydroxyurea ± interferon and scheduled for SCT from an HLA-matched family donor within 6 months after diagnosis (Dx) and from an unrelated donor within 12 months. 85% of the pts were diagnosed in chronic phase (CP). Six pts (3%) died from disease without SCT with a median interval from Dx to death of 6.5 months (range 0.5–12 months) and 25 pts are still searching for a donor. 168 pts underwent SCT (n=50 HLA-matched related; n=69 HLA-matched unrelated (MUD); n=18 HLA-mismatched related; n=31 HLA mismached unrelated) in CP (n=139), in accelerated phase (AP, n=9), in blast crisis (BC, n=9), or in 2. CP (n=10). Probability of overall survival (OS) was 75 % if SCT was performed &lt;7 months after Dx (n=53 pts) and 60 % (n=100 pts) if pts were transplanted later, however, this difference was statistically not significant. Conditioning regimens included either total body irradiation (n=82) or busulfan (n=80) resulting in no statistically different impact on OS. 5-year OS was 82 % for SCT from HLA-matched related and 55% for HLA-MUD-SCT reflecting a higher transplant-related mortality for the latter (p=.0017). After SCT from HLA-mismached unrelated and HLA-mismatched related donors, OS was 56% and 50%, respectively. 12 out of 168 pts (12%) relapsed following SCT after a mean interval of 11 months (range: 1–137 mos) and 9 of them so far have died of CML. Outcome was inferior if SCT was performed in advanced stages of CML (OS of all pts in CP: 67%; in AP: 55%, in BC: 21%, respectively). During the last decade the 3-year OS after SCT from HLA-matched unrelated donors improved gradually from 45 % before the year 1994, to 53 % in the period 1995 to 1999 and to 62 % after 2000, respectively. This large series of pts from a controlled trial shows an excellent OS of 82% for pediatric pts with CML undergoing SCT from matched sibling donors and constantly improving results during the last decade in the setting of MUD-SCT.
Pharmakokinetics of Valganciclovir after AlloSCT: A Fixed Oral Dose Can Be Used for Preemptive Therapy in Patients with Normal Body Weight - Even with Intestinal GVHD.
2004-11-16

Abstract Background: After alloSCT, oral valganciclovir (VALGCV) is a promising alternative to IV GCV against CMV but its pharmacokinetics (PK) have not been studied. Methods: We investigated the PK of GCV after VALGCV in a randomized, crossover phase II-study of 48 patients (pts) after alloSCT. Pts who had &gt;400 copies/ml of CMV DNA in plasma measured by quantitative PCR were randomized to receive a fixed dose of VALGCV 900 mg BID (adjusted for renal function) for 7 days, followed by IV GCV as 1-h-infusion at 5mg/kg every 12 h for another 7 days, or to receive the inverse sequence of study drug administration. The PK of GCV were assessed on days 4 and 11. Safety monitoring was done until day 84 after alloSCT. Results: 28 pts were fully assessable for PK analyses. Among the 22 pts without intestinal graft-versus-host disease (GVHD), the mean±SD AUC 0–12 (mg/L*h) was 53.8±18.0 on VALGCV vs 39.5±13.9 on IV GCV (mean difference 14.3 [95% CI 7.6 to 20.9]); Cmax (mg/L) was 8.8±2.4 vs 10.3±2.1; tmax was 2.7±0.8 vs 1.1±0.6; and t1/2 was 4.2±1.1 vs 3.4±0.8. Among the 6 pts with intestinal GVHD, the mean±SD AUC 0–12 (mg/L*h) was 46.6±24.9 on VALGCV vs 35.3±12.8 on IV GCV (mean difference 11.3 [95% CI −13.4 to 35.9]); Cmax (mg/L) was 7.1±3.6 vs 11.1±3.1; tmax (h) was 2.7±0.8 vs 1.2±0.4; and t1/2 (h) was 5.6±2.0 vs 3.3±0.7. The bioavailability of GCV after VALGCV was 53%. Using a VALGCV fixed oral dose (1.800mg) for preemptive therapy in pts with low body weight led to a sharp increase of the VALGCV / IV GCV ratio (i.e. 50kg = 1.9). With a limited number of pts with low body weight included in this study no severe GCV associated toxicity was seen in these pts. Non-fatal CMV pneumonia developed in 2 pts during follow-up after antiviral therapy, and servere neutropenia &lt; 500/μl occurred in 3 pts. Clearance of CMV DNA was equally effective in both arms. Conclusions: In alloSCT, exposure to GCV after preemptive therapy using VALGCV is higher compared to that with IV GCV in patients with and without intestinal GVHD. In addition to patients with renal dysfunction patients with low body weight &lt; 60kg and normal renal function should be treated very carefully to avoid over-exposure to GCV. Although no severe toxicity was demonstrated in this pk-study a further study to address the safety and efficacy of VALGCV in alloSCT is needed.