Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Anti-tumor effects of etoposide (VP-16), vincristine and mitomycin C were evaluated with four human neuroblastoma xenograft, according to Battelle Columbus Laboratories protocol. Etoposide is one of the agents which has been reported to be effective against advanced neuroblastoma clinically, if combined with other agents. While vincristine was effective against 1 out 4 neuroblastoma xenografts, TS-N-2, with 58.1% maximum inhibition rate, etoposide was assessed ineffective as a single agent in all of the 3 xenografts used. Since etoposide had no effect on the weight gain in nude mice in this xenograft experiment, the dose of etoposide was increased two-fold against 2 xenografts, but found ineffective also in the increased dose. Mitomycin C, which has not been used in childhood malignant tumors, was effective against 2 out of 4 xenografts, TNB-9 and SK-N-AS, with 72.0% and 78.4% maximum inhibition rates, respectively.
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PMID:[In vivo assessment on the therapeutic effects of etoposide, vincristine and mitomycin C against human neuroblastoma]. 190 21

Etoposide (VP-16), 150 mg/M2, given intravenously daily for 3 days every 3 weeks resulted in 3 complete responses and 6 partial responses in 154 patients with a spectrum of recurrent malignant solid tumors. There was evidence of disease control in an additional 37 patients (27 mixed responses and 10 stable disease). These responses occurred primarily in patients with Ewing's sarcoma, Hodgkin's disease, neuroblastoma and rhabdomyosarcoma. Most of the patients had every extensive prior therapy; however prior therapy with teniposide (VM-26), the congener of VP-16, did not seem to preclude responses to the latter drug. Myelosuppression was the principal form of toxicity. Neutropenia characterized by absolute neutrophil counts of 0.5 to 0.9 x 10(9)/L occurred in one-half of the patients, and thrombopenia with platelet counts of less than 25 to 49 x 10(9)/L in one-fourth. These results demonstrate a favorable therapeutic index for VP-16 in several recurrent childhood solid tumors, supporting its use as a component of primary therapy for these diseases.
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PMID:Clinical trial of etoposide (VP-16) in children with recurrent malignant solid tumors. A phase II study from the Pediatric Oncology Group. 341 Jun 65

Etoposide is a semisynthetic podophyllotoxin derivative with a broad spectrum of antitumor activity and a relatively high therapeutic index. The synergism in animal with cis-platinum, cyclophosphamide, BCNU, and cytosinarabinoside is interesting for combination regimen. Mechanisms of action are inhibition of nucleoside transfer and of DNA and RNA synthesis, single stranded breaks, inhibition of protein synthesis and of microtubular assembly. While in lower concentrations etoposide is acting cell-cycle-dependent with accumulation of cells in the G2-phase it has, in high concentrations, also a cellcycle-phase-unspecific lethal effect. Most suitable is the oral and i.v. application of etoposide in fractionated doses of 80--120 mg/m2 on 3--5 consecutive days and repetition after 21 [14--28] days. Side effects are dose-limiting bone marrow toxicity, nausea, vomiting, fever, hypotension, phlebitis, mucositis, neuropathy, cardiotoxicity, alopecia. Etoposide is one of the most active single agents in small-cell bronchus carcinoma with a remission rate of 37% (10% CR), and is very active in NHL (36%), testicular carcinoma (37%), AMML (35%), choriocarcinoma (35%), and neuroblastoma (29%). The role of etoposide in combination with other active drugs in these tumors is currently investigated in bronchus and testicular carcinoma and NHL, where etoposide will belong to the drugs of the first choice in the future.
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PMID:[Etoposide VP 16--213)--a podophyllotoxinderivative with high antitumor activity (author's transl)]. 703 50

This study evaluates the use of a multidrug resistance (MDR) modulator (verapamil) in combination with a standard dose of single-agent etoposide in relapsed or refractory paediatric malignancy. A total of 20 patients (median age 6.5 years) were treated with an infusion of verapamil (loading dose 0.1 mg kg-1, followed by continuous infusion 0.15 mg kg-1 h-1) for 72 h. Etoposide was given daily (150 mg m-2 day-1) for three doses (each over 1 h); the first dose was given 12 h into the verapamil infusion. Cardiovascular toxicity was monitored by ECG and 2 hourly blood pressure and pulse recordings. Verapamil and norverapamil plasma concentrations were measured daily. Disease response was assessed after two courses. A total of 29/35 treatment courses were given at the desired verapamil dose; five courses required a dose reduction owing to cardiovascular toxicity. No patient required intensive monitoring. All patients who developed cardiovascular toxicity were over 14 years old. There was no correlation between plasma verapamil or norverapamil concentrations and toxicity. There were six partial responses (three rhabdomyosarcoma, three neuroblastoma) after two courses, but because of variation in the dose and schedule of etoposide these cannot be unequivocally contributed to MDR reversal. In conclusion, a regimen using a continuous infusion of verapamil combined with divided-dose etoposide is tolerable in children, and this strategy may be effective in refractory neuroblastoma and rhabdomyosarcoma.
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PMID:Continuous-infusion verapamil with etoposide in relapsed or resistant paediatric cancers. 771 Sep 58

Etoposide has demonstrated highly significant clinical activity against a wide variety of neoplasms, including germ-cell malignancies, small-cell lung cancer, non-Hodgkin's lymphomas, leukemias, Kaposi's sarcoma, neuroblastoma, and soft-tissue sarcomas. It is also one of the important agents in the preparatory regimens given prior to bone marrow and peripheral stem-cell rescue. Despite its high degree of efficacy in a number of malignancies, the optimal dose, schedule, and dosing form remain to be defined. It is possible that continuous or prolonged inhibition of the substrate, i. e., topoisomerase II, may be the key factor for the cytotoxic effects of etoposide. Clinical studies have shown the activity of etoposide to be schedule-dependent, with prolonged dosing, best accomplished by the oral dosing form, offering a therapeutic advantage. This benefit awaits validation by prospective randomized studies, some of which are in progress. Recent clinical investigations have focused on the use of etoposide in combination with (a) cytokines to ameliorate myelosuppression, the dose-limiting toxicity of etoposide; (b) agents such as cyclosporin A and verapamil to alter the p-glycoprotein (mdr1) function; and (c) topoisomerase I inhibitors to modulate the substrate upon which it acts. There is continued interest in the development of etoposide to its maximal clinical dimensions and in the examination of alternative biochemical and mechanistic approaches to further our understanding of this highly active agent.
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PMID:Etoposide: current status and future perspectives in the management of malignant neoplasms. 807 20

Hematological and clinical data of 14 children with neuroblastoma treated according to the German neuroblastoma therapy study NB 90 were analyzed. Therapy included 4 or 8 intensive therapy elements N1 (Etoposide 125 mg/m2 day 1-4, Vindesine 3 mg/m2 day 1, Cisplatin 40 mg/m2 day 1-4) and N2 (Vincristine 1.5 mg/m2 day 1 + 8, Dacarbazine 200 mg/m2 day 1-5, Ifosfamide 1500 mg/ m2 day 1-5, Doxorubicin 30 mg/m2 day 6 + 7) in alternating order. The hematological recovery was studied after 86 therapy elements N1/N2. G-CSF had been given in 23 therapy courses, while no cytokine was administered in 63 therapy courses. Mobilization of CD34+ cells was studied in 13 therapy courses with G-CSF. Severe myelosuppression with an absolute neutrophil count < 500/microL was noted 2-4 weeks after each therapy element. The use of G-CSF did not prevent, but shortened neutropenia. There was no difference in the number of infections nor time delay of therapy between the courses with or without G-CSF. In 11 therapy courses G-CSF was started on the day following the last chemotherapy dose (N1: day 5; N2: day 9). In 12 therapy courses G-CSF was given delayed, starting day 12 after the initiation of therapy. Kinetics of granulocyte recovery was similar in the early or delayed application of G-CSF. Neutrophil recovery after the therapy element N1 was earlier and faster compared to that of therapy element N2. The more rapid rise of the neutrophils after the N1 element was accompanied by an effective mobilization of CD34+ cells. Taking into account the limitations of this retrospective study, the data may help to optimize the application of G-CSF in a very intensive therapy study like NB90.
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PMID:[Kinetics of myelopoietic regeneration and mobilization of CD34-positive cells within the scope of the NB90 Neuroblastoma Therapy Study]. 934 Apr 28

We report a multicentre phase II study of orally administered prolonged schedule etoposide in children with refractory or relapsed malignancy. 83 children were entered into the study. The largest diagnostic groups were neuroblastoma (n = 20), rhabdomyosarcoma/soft tissue sarcoma (n = 16) and brain tumours (n = 16). Etoposide was administered twice daily at a dose of 50 mg/m2/day for 21 days using the intravenous preparation given orally. Disease reassessment was performed after the second course. Etoposide plasma concentrations were measured by HPLC, 2 and 6 h after administration of therapy on days 7 and 14 in 15 patients. 61 patients completed two courses and were evaluable for response. There was 1 complete response (CR), 5 partial responses (PR) 22 stable disease (SD) and 33 progressive disease (PD). Of the 6 with responses, 3 had a diagnosis of medulloblastoma/cerebral primitive neuroectodermal tumour. 24 of 26 patients with SD/PR/CR received further courses with excellent palliative effect. The main toxicity observed was myelosuppression, with 8% and 7% of evaluable courses complicated by grade III-IV neutropenia and thrombocytopenia, respectively. Severe infection (grade III-IV) was rare, complicating only 2/94 evaluable courses. Plasma etoposide median concentrations at 2 h after administration on day 7 of course 1 were 1.5 (range 0.6-2.4) micrograms/ml. Total course 1 area under the etoposide plasma concentration versus time curve (AUC) values were estimated using a limited sampling model. Grade > or = 2 leucopenia was only observed in patients with a day 72 h etoposide concentration of > 2 micrograms/ml or a course 1 AUC of > 35 mg/ml.min. It is concluded that given at a dose of 50 mg/m2/day in two doses for 21 day courses, oral etoposide is well tolerated in children. A correlation between drug concentrations and toxicity was observed. Overall, a low response rate was seen (approximately 10%), but disease stabilisation appears to occur, and useful palliative effect was frequently noted. The response in brain tumours was more encouraging (3/14 PR) and this group requires further evaluation.
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PMID:Phase II study of 21 day schedule oral etoposide in children. New Agents Group of the United Kingdom Children's Cancer Study Group (UKCCSG). 947 Aug 39

Staurosporine, a protein kinase and etoposide, a topoisomerase II inhibitor, are known to enhance apoptosis. The differential effects of these agents on T98G glioblastoma and SK-N-SH neuroblastoma, cell lines both derived from human tumors, have not been determined. We assessed cellular viability, DNA fragmentation and laddering, chromatin condensation, and Poly(ADP-ribose) polymerase (PARP) cleavage induced by these agents at a series of concentrations and times. In addition, to gain an understanding of the mechanism by which these agents work, we measured Protein Kinase C (PKC) activity. Staurosporine induced significant alterations in all apoptotic parameters tested in both cell lines. Etoposide induced apoptotic alterations similar to those caused by staurosporine in neuroblastoma but produced no detectable apoptotic changes in glioblastoma cells. Etoposide induced membrane but not cytosolic PKC activity in neuroblastoma but had no effect on PKC activity in glioblastoma. Our results show that the induction of apoptosis is cell type dependent. PKC activity appears to be crucial in the initiation of apoptosis.
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PMID:Differential responses of human neuroblastoma and glioblastoma to apoptosis. 1145 93

The oxidative stress could have a dual action on glutathione S-transferase (GST) P1-1 metabolism: transcriptional induction and/or polymerization. The former should represent a form of adaptation to oxidative stress and contribute to protect the cell, the latter one should activate apoptosis via c-Jun N-terminal kinase (JNK). We studied the effect of etoposide on human neuroblastoma cell line SH-SY5Y and on an etoposide-resistant clone to investigate whether a pleiotropic effect of etoposide on the redox status of the cell exists which is able to interfere with apoptosis through the GST P1-1 system. Etoposide treatment was able to induce GST P1-1 polymerization and activation of apoptosis. The data obtained from our etoposide-resistant clone and the possibility to reverse the sensitive phenotype to a resistant one by means of hexyl-glutathione preincubation, seem to suggest that cellular levels of glutathione have a key role in protecting GST P1-1 by oxidation and consequently the cell's decision between life and death.
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PMID:Role of GST P1-1 in mediating the effect of etoposide on human neuroblastoma cell line Sh-Sy5y. 1211 3

Etoposide, a topoisomerase II poison is used in the treatment of a number of solid tumors. Contradictory data exist on the role of the telomere/telomerase complex in etoposide induced apoptosis. Therefore we examined the effects of etoposide treatment in the neuroblastoma cell line SHSY5Y, with very short telomeres and the acute lymphoblastic T cell line 1301, which displays extremely long telomeres. Both short-term and continuous exposure to the drug were examined. Etoposide induced widespread DNA damage followed by DNA damage foci formation and ultimately growth arrest and apoptosis in a concentration-dependent manner. However, length of telomeres and of single stranded telomeric G rich overhangs did not change significantly under the treatments in any cell line. There was no significant induction of single-strand breaks in the G-rich strand of telomeres. Telomerase activity was transiently upregulated under low concentrations of etoposide, while high concentrations resulted in decreased telomerase activity only after onset of apoptosis. Telomerase overexpression protected against etoposide induced apoptosis in fibroblasts. The data suggest that telomeres are not major signal transducers towards growth arrest or apoptosis after etoposide treatment. However, upregulation of telomerase might be part of an attempted adaptative response, which protects cells by a mechanism that might be independent of telomere length maintenance.
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PMID:The role of telomeres in Etoposide induced tumor cell death. 1532 95


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