Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The severe combined immunodeficient (SCID) mouse model of human acute myelogenous leukemia (AML) is a unique system for preclinical in vivo evaluation of the activity and toxicity of new agents. The topoisomerase I (topo I) inhibitor topotecan is active in patients with AML and myelodysplastic syndromes. DX-8951f is a novel topo I inhibitor with more potent antitumor effects than topotecan or CPT-11 in vitro. To study the in vivo activity of DX-8951f, 6-week-old female SCID mice received injections into the tail vein with 2 x 10(7) exponentially growing KBM-3 cells. In each experiment, three to five sets of five mice were treated with DX-8951f doses ranging from 7.5 to 80 mg/kg and at schedules of 1, 3, and 5 days; a control set of five mice was treated with the drug vehicle alone. One group received DX-8951f on day 7 of the inoculation with KBM-3 (early-treatment group). To study the activity of DX-8951f in advanced disease, a second group was treated 1 month after the inoculation, when the animals were developing symptoms (late-treatment group). The study end point was the duration of survival until death from leukemia, which was assessed clinically and by the presence of the human DQ alpha gene in tissue samples by PCR. Six experiments were conducted with 170 animals. Survival was higher in both the early- and late-treatment groups than in untreated controls, and the treated groups had significantly less central nervous system disease. Significantly improved survival was observed in animals treated early with 60 and 80 mg/kg as a single injection, with 15 and 20 mg/kg over 3 days, and with 7.5 and 10 mg/kg over 5 days. In the late-disease model (treatment starting on days 28-35), improved survival was observed with a single dose of 80 or 20 mg/kg over 5 days. Dose escalation was limited by dilution problems at the 1-day schedule and by toxicity (mainly gastrointestinal) of the prolonged schedules. Both efficacy and toxicity were dose schedule dependent, increasing with higher doses and prolonged exposure. By establishing the antileukemic activity of DX-8951f against human AML transplanted into SCID mice at doses below the LD10, our data provide a rationale for clinical evaluation of the drug in patients with AML and favor the use of prolonged administration.
 ...
PMID:The topoisomerase I inhibitor DX-8951f is active in a severe combined immunodeficient mouse model of human acute myelogenous leukemia. 1069 May 60

E7070 (N-(3-Chloro-7-indolyl)-1,4-benzenedisulphonamide) was selected from our sulphonamide compound collections via antitumour screening and flow cytometric analysis. Following treatment with E7070, the cell cycle progression of P388 murine leukaemia cells was disturbed in the G1 phase. The cell-killing effect on human colon cancer HCT116 cells was found to be time-dependent. In the panel of 42 human tumour cell lines, E7070 showed an antitumour spectrum that was distinct from those of other anticancer drugs used in clinic. Animal tests using human tumour xenograft models demonstrated that E7070 could cause not only tumour growth suppression, but also tumour regression in three of five colorectal and two of two lung cancers. In the HCT116 xenograft model, E7070 was shown to be superior to 5-FU, MMC and CPT-11 (irinotecan). Furthermore, complete regression of advanced LX-1 tumours was observed in 80% of E7070-treated mice. All of these observations have promoted this drug to clinical evaluation.
 ...
PMID:E7070, a novel sulphonamide agent with potent antitumour activity in vitro and in vivo. 1167 18

The treatment of advanced non-small cell lung cancer requires histologic proof of diagnosis, careful staging, and assessment of each patient's performance status and comorbidities. For patients with stage IIIB (pleural effusion) and stage IV disease who have a Cancer and Leukemia Group B performance status (PS) of 0 to 1, appropriate management consists of combination chemotherapy with a platinum (either cisplatin or carboplatin) combined with paclitaxel, gemcitabine, vinorelbine, docetaxel, or CPT-11. Dosages and schedules previously established by large phase II or phase III studies should be followed. Variations in the toxicity patterns, schedules of administration, and economic considerations should guide the selection of the specific regimen. For patients who maintain a good performance status after first-line chemotherapy, second-line treatment may be considered. Current evidence supports the use of docetaxel as second-line treatment if the patient has not previously received this drug. Gemcitabine and paclitaxel may also have activity in this setting. Vinorelbine, ifosfamide, and CPT-11 appear to be inactive as second-line therapy for patients who have previously received platinum-based chemotherapy. For patients with a PS of 2, single-agent chemotherapy with vinorelbine, gemcitabine, or a combination of the two should be considered. Patients with poor performance status should be treated with supportive measures designed to relieve pain and acute complications because any tumor-directed therapy has limited benefit. Special situations exist in which curative therapy for metastatic disease is a possibility. Patients who present with solitary sites of metastatic disease, particularly after a long disease-free interval and in the CNS may undergo definitive surgery or radiotherapy with curative intent. Some have also reported favorable outcomes for patients with solitary adrenal or bone metastases as well. Surgical treatment or definitive radiotherapy should not be employed unless a thorough restaging evaluation is performed that includes computed tomography scan of the chest and abdomen through adrenals, brain magnetic resonance imaging, and positron emission tomography scan. A plethora of new agents targeting angiogenesis, tumor invasiveness, the hypoxic environment of tumors, and the cell cycle are currently in development.
 ...
PMID:Advanced non-small cell lung cancer. 1205 40

CPT-11 is a topoisomerase I (Topo I) inhibitor which was initially described as active in multi-drug resistance (MDR) tumors. The MDR phenomenon is characterized by the overexpression of efflux pumps which are able to extrude a range of drugs non-related chemical or functionally. In this work, we treated leukemic cells with CPT-11 300 microM at 24h and compared its cytotoxicity with the activity of efflux pumps and with cell cycle phase. Our findings show that CPT-11 has a potent anti-tumor activity in leukemic cells regardless MDR phenotype and the cell cycle phase, suggesting new avenues to be explored in leukemia treatment.
 ...
PMID:CPT-11-induced cell death in leukemic cells is not affected by the MDR phenotype. 1253 77

CPT-11 is an antineoplastic agent which acts as a specific inhibitor of DNA topisomerase 1 and has a broad spectrum of activity in solid tumors. Very few studies have evaluated the activity of CPT-11 in hematological malignancies. We conducted a phase II trial of CPT-11 in 26 patients with high-risk MDS (RAEB 1: n = 4; RAEB 2: n = 9; MDS having progressed to AML: n = 10; CMML: n = 3) who could not receive anthracycline/cytarabine intensive chemotherapy. Induction therapy consisted of four courses of CPT-11 given intravenously at 200 mg/m(2) every 2 weeks. Patient characteristics were: median age, 71 (range 51-77); sex, (M/F), 21/5, median % marrow blasts cells, 13.5 (range 7-52). Cytogenetics according to IPSS were: low-risk n = 13, intermediate-risk n = 6, high-risk n = 3, failure or not done n = 4. Six patients stopped treatment after only one or two courses of CPT-11 due to severe infection (n = 2), progressive disease (n = 3), acute lysis syndrome with renal failure (n = 1). In the 20 patients who received at least three cycles of CPT-11, complete remission was achieved in one case, partial remission in four cases, and hematological improvement in three cases with an overall response rate of 33% in the 26 patients. Duration of response was short (median 4 months, range 1-6 months) and median survival was 8 months (range 1-23 months). Digestive toxicity (diarrhea) occurred in 26/89 (29%) courses, but was mild (grade 1, 20% courses; grade 2 or 3, 9% courses). Hematological toxicity was difficult to assess in non-responders because of initial pancytopenia, but all the patients who responded had grade 3/4 hematological toxicity associated with grade >/=2 infection requiring hospitalization in 18% of the courses. No other major toxicity was observed. Thus CPT-11 has an interesting activity in MDS with excess of blasts; toxicity is easily managed and most patients can be treated in the out-clinic setting. These results suggest that further evaluation of CPT-11 in MDS is warranted.
Leukemia 2003 Feb
PMID:Phase II trial of CPT-11 in myelodysplastic syndromes with excess of marrow blasts. 1259 29

Despite the high antitumor activity of camptothecins, few derivatives have been developed and tested for human treatment of solid tumors, due to unpredictable toxicity mainly connected to their poor water solubility. We report the conjugation of the antitumor agent 10-amino-7-hydroxy camptothecin (SN-392) to linear or branched poly(ethylene glycol)s (PEGs) of different loading capacity through a tri- or tetrapeptide spacer selectively cleaved by lysosomal enzymes (cathepsins). A synthetic strategy based on the chemoselective acylation of the aromatic amino group in the presence of the unprotected C20 tertiary alcohol allowed high overall yields. Two conjugates demonstrated good stability at physiological pH and in mouse plasma (nonspecific proteases) but slowly released the drug payload in the presence of the lysosomal enzyme cathepsin B1. Compound 3, selected for in vivo experiments, was very active against P388, P388/ADM leukaemia, and Meth A fibrosarcoma cell lines, scoring T/C% values comparable with the camptothecin derivative CPT-11. Pharmacokinetic studies indicated that 3 acts as a reservoir of 10-amino-7-ethylcamptothecin, as the mean residence time (MRT) is about 3-fold higher than that of the free drug.
 ...
PMID:Synthesis, characterization, and preliminary in vivo tests of new poly(ethylene glycol) conjugates of the antitumor agent 10-amino-7-ethylcamptothecin. 1497 8

A new poly(ethylene glycol) (PEG) conjugate of 10-amino-7-ethyl camptothecin, a potent antitumor analogue of camptothecin, has been synthesized and preliminary in vivo tests have been performed. Successful chemoselective N-acylation of 10-amino-7-ethyl camptothecin was accomplished using phenyl dichlorophosphate, a coupling reagent used in esterification of alcohols, while other coupling methods failed, due to the low nucleophilicity of the amino group in position 10. The conjugate was tested against P388 murine leukemia cell lines and resulted equipotent to CPT-11, a camptothecin analogue already in clinical use.
 ...
PMID:Efficient and chemoselective N-acylation of 10-amino-7-ethyl camptothecin with poly(ethylene glycol). 1502 76

Erythropoietin (EPO) is a protein widely used against drug induced anemia at cancer patients. Irinotecan (CPT-11) is a genotoxic topoisomerase I inhibitor. We investigated the genotoxic, cytostatic and cytotoxic effects of EPO in the presence and in the absence of CPT-11 in human lymphocytes in vitro and in ascites cells of P388 leukemia in vivo. The levels of genotoxicity, cytostaticity and cytotoxicity were evaluated in human lymphocytes in vitro, and in P388 ascites tumor cells in vivo. The results show that EPO is not genotoxic. Unlikely to EPO, CPT-11 caused severe genotoxic, cytostatic and cytotoxic effects by significantly increasing SCE levels and decreasing PRI and MI values in peripheral lymphocytes in vitro and in P388 ascites tumor cells in vivo. Adding EPO in human lymphocyte cultures in vitro and in P388 leukemia bearing mice in vivo in the presence of CPT-11 decreased SCEs levels and increased PRIs and MIs were observed compared with cells treated either in vitro or in vivo with CPT-11 alone, which shows that EPO protected cells from the toxic action of CPT-11. EPO's protective action on human peripheral lymphocytes in vitro and P388 cells in vivo from the topoisomerase I inhibitor CPT-11, lead us to propose it as a geno- and cytoprotective agent.
 ...
PMID:Attenuation of cytogenetic effects by erythropoietin in human lymphocytes in vitro and P388 ascites tumor cells in vivo treated with irinotecan (CPT-11). 1981 85

New camptothecin (CPT) derivatives have recently been synthesized following the finding that CPT has strong antitumor activity due to its inhibition of topoisomerase I through the formation of stable topoisomerase I-DNA cleavable complexes, but has not been clinically used due to its pronounced toxicity. 7-ethyl-10-hydroxy-CPT (SN-38), a metabolite of the CPT derivative 7-ethyl-10-[4-(1-piperidino)-1-piperidino] carbonyloxy-CPT(CPT-11), plays an essential role in mediating the antitumor effect of CPT-11. However, the reasons for the cytotoxicity of SN-38 remain unclear. In this study, we demonstrated using results of DNA fragmentation assay and cell cycle analysis that SN-38 and CPT both induce apoptosis in L1210 murine leukemia cells. We demonstrated in addition that enforced expression of the bcl-2 gene in L1210 cells by MPZenNeo (bcl-2) retroviral gene transfer increased resistance to the apoptosis induced by SN-38 and CPT. These findings suggest the possibility that the bcl-2 gene impedes the activity of a common pathway for apoptosis induced by SN-38 and CPT.
 ...
PMID:Bcl-2 gene prevents induction of apoptosis in l1210 murine leukemia-cells by sn-38, a metabolite of the camptothecin derivative cpt-11. 2156 72

Irinotecan Hydrochloride (CPT-11) and 7-ethyl-10-hydroxycamptothecin (SN-38), which are both topoisomerase I inhibitors with potent antitumor effects in vivo and in vitro, were tested for the induction of programmed cell death (PCD) in leukemia/lymphoma cell lines. When the human T-cell leukemia cell line HUT-102 and the human promyelocytic leukemia cell line HL-60 cells were exposed to CPT-11, PCD characterized by a DNA fragmentation ladder of 180-200 bp in agarose gel electrophoresis and loss of cell viability was induced. The PCD inducing activity of SN-38, an active metabolite of CPT-11, was much more powerful than that of CPT-11. Besides inducing PCD in HUT-102 and HL-60 cells, SN-38 also induced PCD in the human erythroblast leukemia cell line K-562, which was resistant to CPT-11. Induction of PCD by SN-38 and CPT-11 was dose- and time-dependent. PCD in HUT-102 cells induced by SN-38 was prevented neither by aurintricarboxylic acid (ATA), an endonuclease inhibitor, as determine by DNA electrophoretic profiles and the number of viable cells, nor by the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA). The present data suggest that the topoisomerase I inhibitors, SN-38 and CPT-11 exert antitumor activity through induction of PCD in involved cells, at least in part. The PCD-inducing activity of the topoisomerase II inhibitor VP-16 was also tested in the above three cell lines and compared with CPT-11 and SN-38.
 ...
PMID:A new derivative of camptothecin, irinotecan hydrochloride (cpt-11) induces programmed cell-death in leukemia-lymphoma cell-lines. 2157 18


<< Previous 1 2 3 4 Next >>