Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:5.99.1.2 (topoisomerase)
 9,166 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mantle cell lymphoma (MCL) is a mature B-cell proliferation characterized by the presence of translocation t(11;14)(q13;q32), an aggressive clinical course, and poor response to chemotherapy. The majority of drugs currently used in the treatment of lymphoproliferative disorders induce cell death by triggering apoptosis, but few data concerning drug-induced apoptosis in MCL have been reported. We have analysed the mechanisms of drug-induced cell death in four cell lines with the t(11;14) and in primary cells from 10 patients with MCL. Mitoxantrone, a topoisomerase II inhibitor, induced a strong cytotoxic effect in three cell lines (JVM-2, REC-1, and Granta 519), and in primary MCL cells. This cytotoxic effect due to apoptosis induction was observed despite the presence of either p53 or ATM abnormalities. However, no cytotoxic effect was detected after incubation with DNA-damaging agents in the NCEB-1 cell line, carrying p53 and ATM alterations, despite the presence of functional mitochondrial machinery. These results support that mitoxantrone can be effective in the treatment of MCL but that this activity requires the integrity of functional DNA-damage response genes.
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PMID:Activation of mitochondrial apoptotic pathway in mantle cell lymphoma: high sensitivity to mitoxantrone in cases with functional DNA-damage response genes. 1548 Apr 31

The genomic profile of mantle cell lymphoma (MCL) has been reported to be significantly different from that of other indolent lymphoproliferative disorders, Topoisomerase IIalpha, glutathione-s-transferasepi (GSTpi) and ABCG2 (BCRP) chemoresistance genes being over-expressed in MCL. In our study, expression levels of the above mentioned genes plus MDR1 were tested on bone marrow samples from 20 patients treated with Rituximab plus hyper-CVAD regimen, in order to evaluate a possible impact of the chemoresistance phenomenon on this promising treatment regimen. All patients expressed ABCG2 and MDR1 genes; 85% of cases expressed GSTpi and topoisomerase IIalpha. Only ABCG2 were over-expressed in comparison both with marrow from healthy donors and tonsilar CD5+/CD20+ lymphocytes (adopted as normal counterpart of the neoplastic population). The overall response rate of the entire series was 87.5%, with 44% of complete responses. Fifty-seven percent of patients achieved the clearance of minimal residual disease. Levels of tested genes did not condition either quality of clinical response or PFS (76% at 24 months). Nevertheless, an ABCG2 higher expression appeared associated with a worse PFS and levels of this gene paralleled the status of minimal residual disease. A further evaluation of ABCG2 expression in larger series of MCL patients would be suitable.
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PMID:Evaluation of the MDR1, ABCG2, Topoisomerases IIalpha and GSTpi gene expression in patients affected by aggressive mantle cell lymphoma treated by the R-Hyper-CVAD regimen. 1770 72

Improving survival rates in children with malignancy have been achieved at the cost of a high frequency of late adverse effects of treatment, especially in intensively treated patients such as those undergoing haematopoietic stem cell transplantation (HSCT), many of whom suffer the high burden of chronic toxicity. Secondary malignant neoplasms (SMNs) are one of the most devastating late effects, cause much morbidity and are the most frequent cause of late (yet still premature) treatment-related mortality. They occur in up to 7% of HSCT recipients by 20 years post-HSCT, and with no evidence yet of a plateau in incidence with longer follow-up. This review describes the epidemiology, pathogenesis, clinical features and risk factors of the three main categories of post-HSCT SMNs. A wide range of solid SMNs has been described, usually occurring 10 years or more post-HSCT, related most often to previous or conditioning radiotherapy. Therapy-related acute myeloid leukaemia/myelodysplasia occurs earlier, typically three to seven years post-HSCT, mainly in recipients of autologous transplant and is related to previous alkylating agent or topoisomerase II inhibitor chemotherapy. Post-transplant lymphoproliferative disorders occur early (usually within two years) post-HSCT, usually presenting as Epstein-Barr virus-related B cell non-Hodgkin lymphoma.
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PMID:Secondary Malignant Neoplasms Following Haematopoietic Stem Cell Transplantation in Childhood. 2741 56