Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously shown that the synthetic peptide pGlu-Glu-Asp-Cys-Lys (pEEDCK monomer) inhibits the cytostatic drug-induced proliferation of hematopoietic stem cells CFU-S. Keeping CFU-S quiescent by pEEDCK treatment renders them insensitive to cycle-specific cytostatic drugs and leads to reduced toxicity. Here we show that pEEDCK application during repeated (twice) administration of clinically relevant (nonlethal) 1-beta-D-arabinofuranosylcytosine (Ara-C) doses reduced the percentage of CFU-S in S-phase from 60%-70% to 25%-30% and led to a sustained stem cell number in the bone marrow (BM), whereas unprotected mice had lost about 75% of their CFU-S population. Owing to its cysteine content, the pEEDCK monomer is easily oxidized. The resulting dimer (pEEDCK)2 is a potent stimulator of hematopoiesis. As we show, it can be used for postchemotherapy acceleration of hematologic recovery, similar to the use of recombinant hematopoietic growth factors. A single injection of 30 micrograms/kg pEEDCK monomer to mice 2 hours before the second Ara-C injection retarded onset of neutropenia (by 2 to 3 days) and improved recovery after depression. The quantitative degree of neutropenia was not changed. Postchemotherapy (Ara-C administered twice, followed by N-mustard) infusion of the stimulatory (pEEDCK)2 dimer (1.4 micrograms/kg/d) produced a 4.6-fold increase of progenitor levels (6.7 CFU-GM/1,000 BM cells v 1.45 CFU-GM/1,000 in normal mice) 2 days after the end of the cytostatic treatment when CFU-GM were not detectable in unprotected mice. This increase was followed after several days by strongly elevated granulocyte counts, which remained high for approximately 1 week. Up to 75% of the peripheral leukocytes were mature polymorphonuclear leukocytes (PMN) during this phase. Ara-C (twice) and monomer treatment as above followed by dimer infusion resulted in the complete protection of hematopoiesis. Mice treated with the protective pEEDCK monomer plus stimulatory dimer did not develop the leukocyte depression noted in unprotected animals. The inhibitory monomer appears to keep the stem cell population numerically and qualitatively intact, thus providing optimum target cell conditions for the subsequent stimulator (dimer) treatment. Our results show that the hemoregulatory peptide monomer and dimer can be used for improving the hematologic status of mice treated with clinically relevant doses of cytostatic drugs (antimetabolite and alkylating, alone and in combination). Combining both peptides can prevent occurrence of neutropenia completely. Both peptides can be obtained easily by chemical synthesis and are also active on human cells. They are thus highly promising candidates for application as multilevel hemoprotectors in cancer chemotherapy.
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PMID:Protection from arabinofuranosylcytosine and n-mustard-induced myelotoxicity using hemoregulatory peptide pGlu-Glu-Asp-Cys-Lys monomer and dimer. 200 54

We have previously shown that the stem cell inhibitory peptide pGlu-Glu-Asp-Cys-Lys (pEEDCK monomer) leads to a good tolerance of otherwise lethal multiple ara-C doses and an increased survival of ara-C + peptide treated mice. This effect was due to the prevention of drug-induced CFU-S proliferation, thus keeping stem cells in a quiescent state insensitive to ara-C. Here we show that the pEEDCK monomer also inhibits stem cell proliferation after clinically relevant (non-lethal) ara-C doses. This leads to a sustained (100%) stem cell number in the femoral bone marrow, which was greatly reduced without protective peptide treatment (27%). We have measured the kinetics of influx of CFU-S into the empty S-phase (after two consecutive ara-C injections). This influx reached peak levels of 60-70%; pEEDCK treatment reduced it to 25-30%. Due to its cysteine content the pEEDCK monomer is easily oxidized and forms a symmetric disulfide-bonded dimer (pEEDCK)2. This dimer is a potent stimulator of haemopoiesis. Various modes of protective peptide treatment (monomer and dimer) were investigated in conjunction with a standardized protocol of 2 x 300 mg/kg ara-C given 12 h apart. (a) ara-monomer-ara: The administration of pEEDCK-monomer 2 h before the second ara-C injection retarded the onset of neutropenia, shortened its duration and improved recovery after depression. The degree of short-term neutropenia was not changed. (b) ara-ara-HN2-dimer: Post chemotherapy infusion of the stimulatory (pEEDCK)2 dimer led to considerable increases of progenitor levels (6.8 CFU-GM/1000 bone marrow cells vs. 1.2 CFU-GM/1000 in normal mice) 2 days after cytostatic treatment when CFU-GM were not detectable in unprotected mice. This increase was followed by greatly elevated granulocyte counts (8000 PMN/mm3 vs. 750 PMN/mm3 in normal mice). In the dimer-treated mice, up to 75% of the peripheral leukocytes were mature PMN (normal, 10%). (c) ara-monomer-ara-dimer: ara-C and monomer treatment as above (a) followed by dimer infusion led to complete protection of haemopoiesis. Mice treated with the protective pEEDCK monomer plus stimulatory dimer did not develop the leukocyte depression seen in unprotected animals. Our results show that the haemoregulatory peptide monomer and dimer can be used to improve the haematological status of mice treated with clinically relevant doses of cytostatic drugs (anti-metabolite and alkylating, alone and in combination). The pEEDCK monomer and dimer are equally active also on human haemopoietic cells.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The use of haemoregulatory peptides (pEEDCK monomer and dimer) for reduction of cytostatic drug induced haemopoietic damage. 227 50

Interleukin 11 (IL-11) is a multifunctional cytokine which may play a role in regulating the growth and development of cells in both the hematopoietic and lymphoid systems. IL-11 activity was originally detected in the conditioned medium of a primate bone marrow stromal cell line, and the human cDNA was cloned from a human fetal lung fibroblast cell line. The purified protein shows multifunctional activity, influencing lymphohematopoietic stem cell proliferation and differentiation, megakaryocyte progenitor cell proliferation and differentiation, erythroid progenitor cell proliferation, B lymphocyte maturation, activation of hepatocyte acute phase protein synthesis, and adipogenesis. At the molecular level, IL-11 is unique, containing no asparagine-linked glycosylation sites and no cysteine residues. The IL-11 receptor belongs to a family of cytokine receptors which includes the receptors for IL-6, leukemia inhibitory factor (LIF), oncostatin M (OSM), and ciliary neurotrophic factor (CNTF), which are all capable of interacting with the signal transducing receptor gp130 after ligand binding. IL-11 has demonstrated activity in preclinical models for the treatment of thrombocytopenia and, in some cases, neutropenia; studies are underway to confirm its usefulness in the clinic for treatment of myelosuppression associated with cancer chemotherapy and bone marrow transplantation.
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PMID:The biology of interleukin 11. 840 Dec 58

Novel recombinant human C5a receptor antagonists were discovered through modification of the C terminus of C5a. The C5a1-71T1M,C27S,Q71C monomer, (C5aRAM; CGS 27913), was a pure and potent functional antagonist. The importance of a C-terminal cysteine at position 71 to antagonist properties of C5aRAM was confirmed by studying C5a1-71 derivatives with replacements of Q71, C5a derivatives of various lengths (70-74) with C-terminal cysteines, and C5a derivatives of various lengths (71-74) with Q71C replacements. The majority of C5a1-71Q71 derivatives were agonists (C5a-like) in the human neutrophil C5a-induced intracellular calcium mobilization assay. The C5a1-71Q71C derivative was an antagonist. C5a derivatives of lengths 73 and 74 with C-terminal cysteines were agonists, while lengths 70 to 72 were antagonists. C5a derivatives of lengths 72, 73, and 74 with Q71C replacements were agonists, while, again, C5a1-71Q71C was an antagonist. C5aRAM and its adducts, including its dimer, C5aRAD (CGS 32359), were pure antagonists. Additionally, CSaRAM and CSaRAD inhibited binding of 125I-labeled recombinant human C5a to neutrophil membranes (Ki = 79 and 2 pM, respectively), C5a-stimulated neutrophil intracellular calcium mobilization (8 and 13 nM), CD11b integrin up-regulation (10 and 1 nM), superoxide generation (182 and 282 nM), lysozyme release (1 and 2 microM), and chemotaxis (11 and 7 microM). In vivo, intradermal injection of C5aRAM inhibited C5a-induced dermal edema in rabbits. Furthermore, a 5-mg/kg i.v. bolus of C5aRAD significantly inhibited C5a-induced neutropenia in micropigs when challenged with C5a 30 min after C5aRAD administration. C5aRAM and C5aRAD are novel, potent C5a receptor antagonists devoid of agonist or proinflammatory activity with demonstrated efficacy in vitro and in vivo.
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PMID:Novel C5a receptor antagonists regulate neutrophil functions in vitro and in vivo. 960 67

The stem cells of the bone marrow have the capacity for both self-renewal and derivation of all the blood cell lineages. Consequently, toxicity to these cells can result in neutropenia, agranulocytosis, thrombocytopenia, pancytopenia, or aplastic anemia. Many anticancer drugs adversely affect the bone marrow, and neutropenia is a common limiting factor in dose escalation. In this review, we discuss agents that appear to have potential as bone marrow sparing agents. Computerized catalogs of the National Library of Medicine and Medline were searched for reports on low-molecular-weight compounds that detailed effects on the hematopoietic progenitor cells. The most promising agents are the endogenous peptides p-glutamic acid-glutamic acid-aspartic acid-cysteine-lysine and acetyl-serine-aspartic acid-lysine-proline, and the exogenous compounds amifostine and ammonium trichloro[dioxoethylene-O,O']tellurate, but several others are also discussed. These compounds preserve stem cell function in the presence of antineoplastic drugs of diverse pharmacological classes, and they do so by various mechanisms of action. Their present status in clinical practice is also detailed. More needs to be learned about their mechanisms of action and therapeutic potential, but the results are encouraging for some of these compounds and more clinical trials should be expected.
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PMID:Bone marrow stem cell protection from chemotherapy by low--molecular-weight compounds. 1116 51

An open, non-randomized phase II study was carried out including all patients treated with whatever chemotherapy or combined modality regimen for whatever cancer who were in clinical objective response or stable disease (SD) for more than three months, to receive maintenance treatment with recombinant interleukin-2 (rIL-2) plus medroxyprogesterone acetate (MPA) plus antioxidant agents alpha-lipoic acid (ALA) and N-acetyl cysteine (NAC). The main study endpoints were clinical outcome and toxicity. The secondary endpoints were effects of treatment on cancer-related anorexia/cachexia syndrome (CACS) symptoms, on serum levels of proinflammatory cytokines, IL-2, C-reactive protein (CRP) and leptin as well as the evaluation of quality of life (QL). rIL-2 was administered at a dose of 1.8 MIU subcutaneously three times/week on alternate days for the first two weeks of every month and MPA was given orally at a dose of 500 mg once a day at alternate days without interruption. ALA 300 mg/day orally and NAC 1800 mg/day orally were also administered. The treatment was administered until progression of disease or appearance of toxicity. From July 1998 to May 2000, 16 patients were enrolled in the study (M/F ratio: 15/1; mean age: 62 years, range 45-71). The median duration of maintenance treatment was 10 months (range 5-22). The response to maintenance treatment at September 2000 was: CR (persistent throughout the treatment) 4 patients (25%); SD 1 patient (6.2%); PD 11 patients (68.8%). The median duration of response was 9.8 months (range: 5-22+). The median follow-up duration was 19 months (range: 8-102). The median OS was not reached. The median PFS was 14 months (range 1-29). The 1-year survival rate was 25%. At September 2000, 9 patients are still surviving. No grade 3/4 toxicity was observed. One Grade 2 skin toxicity was observed and Grade 1: 2 fever, 2 thrombocytopenia, 1 neutropenia and 1 skin were observed. The ECOG PS did worsen significantly, the body weight and BMI increased significantly after treatment, whereas the appetite did not change significantly. The QL evaluation showed a significant amelioration of cognitive functions and a borderline significant amelioration of emotional functions after treatment, whereas a borderline worsening of dyspnea was observed. The absolute lymphocyte count increased significantly after the maintenance treatment, as well as the serum IL-2, TNFalpha decreased at borderline statistical significance; the serum levels of leptin did not change significantly. The evaluation of patient subgroups showed that responders/survivors had a pattern superimposable to that of whole patient population, the patients who rapidly progressed and died exhibited no significant changes of these parameters during treatment. The results of the present study suggest that the host immune response, evaluated by several parameters, after IL-2 administration, (e.g. lymphocytosis), are worth further study as potential markers for the major end points of cancer treatment, i.e. OS and QL, in an adequate number of patients.
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PMID:Immunotherapy (recombinant interleukin 2), hormone therapy (medroxyprogesterone acetate) and antioxidant agents as combined maintenance treatment of responders to previous chemotherapy. 1117 8

The purpose of the study was to evaluate the effectiveness in terms of response rates, toxicity and survival of the combination chemotherapy regimen cisplatin and epidoxorubicin (epirubicin) including medroxyprogesterone acetate (MPA), recombinant IL-2 (rIL-2) and antioxidants in patients with advanced (stage IIIB-IV) non-small cell lung cancer (NSCLC). Thirty-three chemotherapy-naive patients with NSCLC were enrolled in the study and 30 of them were evaluable. The mean age of the patients was 61 years. Twenty (66.7%) out of 30 patients were >or=60 years, and 5 (16.7%) patients were >or=70 years. The ECOG performance status was 0 to 1 in 30 patients and 2 in 3 patients. Twenty-six patients (78.8%) had stage IIIB disease and 7 (21.2%) had stage IV; histology was mainly squamous cell carcinoma (72.7%). The treatment consisted of cisplatin 40 mg/m2/week and epirubicin 40 mg/m2/week both intravenously on day 1, rIL-2 1.8 MIU/day subcutaneously, MPA 1 g/day orally, alpha-lipoic acid 300 mg/day orally and N-acetyl cysteine 1.8 g/day orally. The treatment was administered for 6 weeks. Patients with a complete response (CR), partial response (PR) or stable disease (SD) continued the treatment, according to response re-evaluation, until 15 weeks. The present study reports the results of 6, 9, 12 and 15-week treatment. After 6 weeks, 30 patients were assessable for response: no CR was observed, a PR was achieved in 15 patients (50%; ORR 50%). After 15 weeks, 1 CR and 8 PR were observed (ORR 30.0%). The median follow-up period was 13 months. The median duration of response was 9 months. The median overall survival (OS) was 15 months. The one-year survival rate was 55.8%. The median progression-free survival (PFS) was 10 months. The toxicity was, as expected, mainly hematologic: neutropenia was the most significant symptom. The non-hematologic toxicity was quite low. Therefore, the treatment's toxicity was quite acceptable. There was no toxic death. The 30.0% ORR, the 15 month OS and the 10 month PFS obtained in this study are comparable with those observed with cisplatin plus epirubicin (ORR 39-54%) in phase II studies and in a previous phase III study (ORR 33%, OS 10.5 months). Moreover, the toxicity was acceptable and it was mainly hematologic. Serum levels of proinflammatory cytokines significantly decreased after treatment.
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PMID:Dose-intense phase II study of weekly cisplatin and epidoxorubicin plus medroxyprogesterone acetate and recombinant interleukin 2 in stage IIIB-IV non-small cell lung cancer. 1195 47

Granulocyte macrophage colony-stimulating factor (GM-CSF) stimulates proliferation of hematopoietic cells of the macrophage and granulocyte lineages and is used clinically to treat neutropenia and other myeloid disorders. Because of its short circulating half-life, GM-CSF is administered to patients by daily injection. We describe here the engineering of highly potent, long-acting human GM-CSF proteins through site-specific modification of GM-CSF cysteine analogues with a cysteine-reactive poly(ethylene glycol) (PEG) reagent. Thirteen cysteine analogues of GM-CSF were constructed, primarily in nonhelical regions of the protein believed to lie away from the major receptor binding sites. The GM-CSF cysteine analogues were properly processed but insoluble following secretion into the Escherichia coli periplasm. The proteins were refolded and purified by column chromatography. Ten of the cysteine analogues could be modified with a 5-kDa maleimide PEG, and seven of the mono-PEGylated proteins were purified by ion-exchange column chromatography. Biological activities of the 13 cysteine analogues and 7 PEGylated cysteine analogues were comparable to that of wild-type GM-CSF in an in vitro cell proliferation assay using human TF-1 cells. One cysteine analogue was modified with larger 10-, 20-, and 40-kDa PEGs, with only minimal loss of in vitro bioactivity. Pharmacokinetic experiments in rats demonstrated that the PEGylated proteins had up to 47-fold longer circulating half-lives than wild-type GM-CSF. These data demonstrate the utility of site-specific PEGylation for creating highly potent, long-acting GM-CSF analogues and provide further evidence that the nonhelical regions of human GM-CSF examined are largely nonessential for biological activity of the protein.
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PMID:Site-specific PEGylation of engineered cysteine analogues of recombinant human granulocyte-macrophage colony-stimulating factor. 1617 10

Taxanes are standard treatment for metastatic breast cancer; however, the solvents used as vehicles in these formulations cause severe toxicities. The FDA recently approved a solvent-free formulation of paclitaxel for the treatment of metastatic breast cancer that utilises 130-nanometer albumin-bound (nab) technology (Abraxane; nab-paclitaxel) to circumvent the requirement for solvents. nab-Paclitaxel utilises the natural properties of albumin to reversibly bind paclitaxel, transport it across the endothelial cell and concentrate it in areas of tumour. The proposed mechanism of drug delivery involves, in part, glycoprotein 60-mediated endothelial cell transcytosis of paclitaxel-bound albumin and accumulation in the area of tumour by albumin binding to SPARC (secreted protein, acidic and rich in cysteine). Clinical studies have shown that nab-paclitaxel is significantly more effective than paclitaxel formulated as Cremophor EL (CrEL, Taxol, CrEL-paclitaxel), with almost double the response rate, increased time to disease progression and increased survival in second-line patients. The absence of CrEL from the formulation is associated with decreased neutropenia and rapid improvement of peripheral neuropathy with nab-paclitaxel, compared with CrEL-paclitaxel. For these reasons, nab-paclitaxel can be administered using higher doses of paclitaxel than that achievable with CrEL-paclitaxel, with shorter infusion duration and without the requirement for corticosteroid and antihistamine premedication to reduce the risk of solvent-mediated hypersensitivity reactions. Taken together, these studies have demonstrated that nab technology has increased the therapeutic index of paclitaxel compared with the conventional, solvent-based formulation.
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PMID:Albumin-bound paclitaxel: a next-generation taxane. 1672 14

Granulocyte colony-stimulating factor (G-CSF) is a multifunctional cytokine which is widely used for treating neutropenia in humans. Evaluation of alternative to expensive components of redox buffer (reduced and oxidized glutathione) is an important step in reducing the cost of production of human biotherapeutic proteins. In the present study, refolding of recombinant human G-CSF expressed as inclusion bodies (IBs) in E. coli was optimized using cysteine and cystine redox agents. The refolding to correct native form of G-CSF was assessed by reverse phase high performance liquid chromatography (RP-HPLC). The optimized concentrations of cysteine and cystine for correct refolding of G-CSF were found to be 2 mM and 1 mM, respectively. The correctly refolded G-CSF was detected as early as 4 h of incubation in renaturation buffer containing optimized concentrations of cysteine (2 mM) and cystine (1 mM) redox agents. Refolding of G-CSF in optimized redox system increased with increase in shuffling time. Overall, the results suggested the use of cysteine/cystine redox pair could be an alternative to the costlier redox pairs for successful refolding of G-CSF and possibly other human biotherapeutic proteins of importance.
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PMID:Refolding of recombinant human granulocyte colony stimulating factor: effect of cysteine/cystine redox system. 2307 91


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