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

The epipodophyllotoxins etoposide and teniposide are probably the most important drugs in the treatment of small cell lung cancer. The drugs are used in maximally tolerated doses, and the toxicity of the drugs precludes significant dose increments. The cellular target is the nuclear enzyme topoisomerase II which, in the presence of these drugs, causes an extensive fragmentation of DNA. The cell kill can be antagonized by distinct drug types. We have demonstrated previously that the intercalating drug aclarubicin and the cardioprotecting agent ICRF-187 antagonize the cytotoxicity of etoposide in vitro. We have studied possible ways of using this antagonism as a means of differentially protecting normal tissue. Here we demonstrate that the intercalating agent chloroquine prevents the introduction of topoisomerase II-mediated DNA breaks and thereby antagonizes the cytotoxicity of etoposide. This interaction depends on the extracellular pH. Chloroquine, in contrast to etoposide, is a weak base and therefore does not enter the cell if the extracellular fluid is acidic, as is the case in most solid tumors. We propose that such a pH-dependent drug interaction may be useful in directing topoisomerase II drug effects toward solid tumors. Thus, by lowering the extracellular pH (pHe) from neutral (pHe = 7.4) to acidic (pHe = 6.0), [3H]chloroquine accumulation was decreased 5-fold in a human small cell lung cancer cell line, OC-NYH, and in murine leukemia L1210 cells. In parallel, the antagonism exhibited by chloroquine on etoposide cytotoxicity was pHe dependent. Thus, no protection by chloroquine was observed at pHe = 6.5, whereas at pHe = 7.4, etoposide cytotoxicity was almost completely antagonized with a 460-fold protection or more than eight doublings of the cell population. This exploitation of antagonist extracellular trapping by acidic pH is a novel model for regulation of anticancer drug effects.
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PMID:Targeting the cytotoxicity of topoisomerase II-directed epipodophyllotoxins to tumor cells in acidic environments. 818 81

We developed an IgG1 mouse monoclonal antibody (ONS-M21) directed against a cell surface antigen of medulloblastomas and gliomas in immunisation of mice with the ONS-76 medulloblastoma cell line. The antibody specifically reacted with medulloblastomas, supratentorial primitive neuroectodermal tumours (SPNETs) and gliomas, but not with other neuroectodermally derived tumours (neuroblastoma and melanoma) or with other kinds of tumours (meningioma, neurinoma, leukaemia, and small cell lung cancer). No reactivity was identified with normal body tissues, including peripheral blood cells. Characterisation of the ONS-M21 antigen showed that it was a trypsin-sensitive glycoprotein with a molecular weight of 80 kDa on SDS-PAGE. The pattern of reactivity and the biochemical properties of this antigen were different from those of other markers of medulloblastoma. These results indicate that ONS-M21 detects a new tumour-associated cell surface antigen specifically expressed by medulloblastomas, SPNETs, and gliomas. This is the first report that medulloblastomas may share common cell surface antigens with gliomas, although most studies have concluded that medulloblastoma has a predominantly neuronal phenotype. The lack of reactivity with normal tissue implies that ONS-M21 has potential applications as both a diagnostic tool and a therapeutic agent.
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PMID:Characterisation of a new mouse monoclonal antibody (ONS-M21) reactive with both medulloblastomas and gliomas. 821 97

The retinoblastoma gene (RB) is a growth suppressor gene on the human chromosome 13q14. It encodes a 105 kDa phosphoprotein (p105), with DNA-binding capacity. P105 is thought to be involved in cell cycle control. Inactivation of RB is responsible for the development of retinoblastomas and occurs frequently in osteosarcomas and small cell lung cancer. In this study we looked at the RB-structure and expression in cell lines and primary lymphoma samples from patients with high grade non-Hodgkin's lymphoma (NHL). Forty five primary high grade NHL, the B-lymphoblastoid cell line IM-9 and the NHL cell line WSU-NHL were studied for RB structure by Southern blotting and for RB-expression by Northern blotting, Western blotting and immunocytochemistry. In all experiments freshly cryopreserved material was used. Southern and Northern experiments were performed with the 0.9 kb and 3.8 kb RB-cDNA probe. For the detection of p105 two different anti-p105-monoclonal antibodies were used in immunocytochemistry and Western blotting experiments. No RB mRNA and no p105 could be found in IM-9 cells. Twenty six high grade NHL samples (58%) showed no p105 expression. In the subgroup of centroblastic lymphomas 16 out of 21 and in Burkitt's lymphomas five out of eight showed no p105-expression. P105 expression is absent in 58% of high grade NHL, particularly in centroblastic and Burkitt's lymphomas, suggesting that inactivation of RB may play a crucial role in the pathogenesis of high grade NHL.
Leukemia 1994 Jan
PMID:Altered expression of the retinoblastoma gene product in human high grade non-Hodgkin's lymphomas. 828 6

A number of various thioethers derived from 3-hydrazone-5,6-diphenyl-1,2,4-triazines have been synthesized and evaluated for anticancer and anti HIV activities. The structures are supported by elemental analysis, IR, UV and 1H-NMR spectral data. Most of the tested compounds displayed a significant activity against Leukemia/Lymphoma, CNS, Ovarian and Small cell lung cancer.
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PMID:Synthesis of some new thioethers of 1,2,4-triazine-3-hydrazones and assays for their anticancer and anti human immune virus activities. 832 71

Between April 1981 and December 1987, 148 patients with newly diagnosed small cell lung cancer (SCLC) were treated using combination chemotherapy with or without thoracic irradiation and prophylactic cranial irradiation (PCI) in a series of cooperative therapeutic trials. With a minimum follow-up of 4.7 years, 13 (9%) patients survived and were free of SCLC. These included 11 (15%) of 76 patients with limited disease and two (3%) of 72 patients with extensive disease. Three died without any evidence of SCLC (one each from second leukemia, non-small cell lung cancer, and unrelated disease). The remaining 10 (7%) patients are currently alive and free of SCLC beyond 4.7 years. Since late relapse beyond 5 years is a very rare event, these patients may have been cured. However, late toxicity of PCI must be kept in mind. Three among the 10 patients have suffered from neuropsychologic symptoms of varying degrees in severity. Although the long-term survival rate is a benchmark in the treatment of SCLC, modifications of therapy that may potentially avoid such toxicities should be considered hereafter.
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PMID:Long-term results of combination chemotherapy with or without irradiation in small cell lung cancer: a 5- to 11-year follow-up. 839 5

The daphnane-type diterpene gnidimacrin, isolated from the root of the Chinese plant, Stellera chamaejasme L., was found to strongly inhibit cell growth of human leukemias, stomach cancers and non-small cell lung cancers in vitro at concentrations of 10(-9) to 10(-10) M. On the other hand, even at 10(-6) to 10(-5) M, the small cell lung cancer cell line H69 and the hepatoma cell line HLE were refractory to gnidimacrin. The agent showed significant antitumor activity against murine leukemias and solid tumors in an in vivo system. In K562, a sensitive human leukemia cell line, gnidimacrin induced blebbing of the cell surface, which was completely inhibited by staurosporine at concentrations above 10(-8) M, and arrested the cell cycle transiently to G2 and finally the G1 phase at growth-inhibitory concentrations. It inhibited phorbol-12,13-dibutyrate(PDBu) binding to K562 cells and directly stimulated protein kinase C (PKC) activity in the cells in a dose-dependent manner (3-100 nM). Although activation of PKC isolated from refractory H69 cells was observed only with 100 nM gnidimacrin, the degree of activation was lower than that produced by 3 nM in K562 cells. Our results suggest that gnidimacrin acts as a PKC activator for tumor cells and that this mechanism may be responsible for its antitumor activity.
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PMID:Antitumor activity of daphnane-type diterpene gnidimacrin isolated from Stellera chamaejasme L. 860 23

Small cell lung cancer (stage IIIB) developed in a 61-year-old woman. She was treated with chemotherapy in which the cumulative dose of carboplatin was 662 mg/m2 and that of etoposide was 2,000 mg/ m2, and with concurrent irradiation in which the total dose of X-rays was 44.8 Gy. The response to chemotherapy and irradiation was very good. Radiation pneumonitis developed after discharge, but it resolved after steroid therapy. Nine months after the diagnosis of lung cancer the patient was readmitted because of bleeding and leukocytosis. Acute monocytic leukemia (M5a) was diagnosed after examination of a bone-marrow aspirate. The patient was treated with chemotherapy, but she died of severe bone-marrow suppression and multiple organ failure 3 months after the diagnosis of acute monocytic leukemia. Although chromosome analysis could not be done, we strongly suspect that this leukemia was induced by etoposide, because of the clinical course.
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PMID:[Small cell lung cancer with acute monocytic leukemia after combined chemotherapy including etoposide]. 923 39

We report a series of four patients in whom the onset of systemic cancer was heralded by dysautonomic symptoms and a neurological non-metastatic complication mediated by immunological and endocrine factors. The series includes: a patient with acute leukaemia and autonomic sensory-motor polyradiculoneuropathy, a patient affected by colon carcinoma and autonomic neuropathy and limbic encephalitis, a patient with lung cancer and autonomic neuropathy and hypercalcaemic encephalopathy, a patient with small cell lung cancer associated with autonomic neuropathy in Lambert-Eaton Myasthenic Syndrome (LEMS) and syndrome of inappropriate ADH secretion (SIADH). We underline the prognostic importance and discuss the possible etiopathogenetic role of autonomic dysfunction, which is frequently associated with paraneoplastic neurologic syndromes of autoimmune and/or dysendocrine origin.
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PMID:Immunological and endocrinological abnormalities in paraneoplastic disorders with involvement of the autonomic nervous system. 924 63

In a prior Cancer and Leukemia Group B (CALGB), 16% of a small cohort of patients with extensive small call lung cancer who had failed to obtain a complete remission with chemotherapy did obtain a complete remission after therapy with interleukin-2 (IL-2). In this current trial, 10 patients with extensive small cell lung cancer who had had no prior therapy were treated with subcutaneous IL-2 as induction therapy and then standard chemotherapy with etoposide/cisplatin. Only one patient experienced an objective response to the IL-2 administered prior to chemotherapy. The factors governing response to IL-2 in the first trial but not in this trial are discussed.
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PMID:Subcutaneous interleukin-2 as initial therapy for patients with extensive small cell lung cancer: a phase II trial of Cancer and Leukemia Group B. 949 37

XK469 (NSC 656889) is a water-soluble member of the novel quinoxaline family of antitumor agents. In vitro, XK469 demonstrated selective cytotoxicity for several murine solid tumors including colorectal and mammary adenocarcinoma cell lines, when compared to both leukemia and normal epithelial cells. In vivo, XK469 was active against 7/7 murine tumors tested, including pancreatic ductal carcinomas #02 and #03, colon adenocarcinomas #38 and #51/A, mammary adenocarcinoma #16/C and the Adriamycin resistant mammary adenocarcinomas #16/C/ADR and #17/ADR. XK469 was efficacious both intravenously and orally. Regardless of dosing schedule, conventional mice tolerated higher total doses than SCID or nu/nu mice did. Despite these reduced doses, XK469 was active against xenografts of 4/6 human tumor lines including mammary adenocarcinoma MX-1, the small cell lung cancer DMS 273, the prostate model LNCaP and the CNS tumor SF295. The lower doses in the xenograft studies were below curative levels. The dose-limiting toxicity appeared to be myelosuppression with rapid host recovery (5-8 days), and in vitro assays of XK469 toxicity to murine bone marrow neutrophil progenitors CFU-GM (colony forming unit-granulocyte/macrophage) demonstrated concentration-dependent toxicity from 0.5-30 microg/mL. The difference in drug tolerance between BDF1 and SCID mice was detected in vitro as a 3-fold difference in the IC90 for CFU-GM, despite similar IC50 values. Comparative in vitro hematotoxicology studies revealed that human bone marrow CFU-GM tolerated XK469 as well as their SCID counterparts (IC90 values 5.7 vs. 7.4 microg/mL). Based on comparison with previously tested anti-cancer agents, these data suggest that humans will be able to tolerate XK469 doses that are efficacious against human tumor xenografts.
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PMID:Preclinical antitumor activity of XK469 (NSC 656889). 1042 60


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