brivudine and Breast-Neoplasms

A 66-year-old woman with metastatic mammary carcinoma, who was being treated with capecitabine, contracted a herpes zoster infection that was treated with the antiviral drug brivudin. A drug-drug interaction between brivudin and capecitabine caused medullar aplasia, serious toxic effects to the intestinal mucous membrane, hand-foot syndrome, onycholysis and dental pigmentation.. Physical examination, blood analysis, blood cultures, chest X-ray, bone marrow aspiration and biopsy.. Serious adverse event secondary to inhibition of dihydropyrimidine dehydrogenase by a drug-drug interaction between capecitabine and brivudin.. Intravenous hydration, imipenem, red blood cell and platelet transfusions, filgrastim, omeprazole, care of the mouth and feet, topical anesthetics, systemic analgesics and parenteral nutrition.

Topics: Aged; Anemia, Aplastic; Antimetabolites, Antineoplastic; Antineoplastic Combined Chemotherapy Protocols; Antiviral Agents; Breast Neoplasms; Bromodeoxyuridine; Capecitabine; Carcinoma, Ductal, Breast; Combined Modality Therapy; Deoxycytidine; Dihydrouracil Dehydrogenase (NADP); Drug Interactions; Fatal Outcome; Female; Fluorouracil; Herpes Zoster; Humans; Onycholysis; Palliative Care; Peripheral Nervous System Diseases; Salvage Therapy; Stomatitis; Tooth Discoloration

Gene transfer using different viral vectors has demonstrated different antitumor effects in suicide gene therapy. In the present study, in order to optimize the efficacy of replication-defective adenoviral and lentiviral vectors for gene therapy, RT-PCR was used to evaluate the expression of Drosophila melanogaster deoxyribonucleoside kinase (Dm-dNK) in the Bcap37 human breast cancer cell line, dThd was used to determine the activity of Dm-dNK, cell cytotoxicity was evaluated by MTT assay and cell proliferation was assessed using a hemocytometer. Moreover, apoptosis induction was evaluated by the Annexin V-FITC-labeled FACS method. Furthermore, BALB/C nude mice bearing tumors were treated with Dm-dNK mediated with the pyrimidine nucleoside analog, brivudine [BVDU, (E)-5-(2-bromovinyl)-2'-deoxyuridine]. Our results indicated that the gene expression of Dm-dNK transfected by adenoviral and lentiviral vectors may be detected and that its long-term activity may be retained. Both vectors containing the Dm-dNK gene revealed high cytotoxicity and sensitized cell apoptosis from the BVDU prodrug. In tumor models, lentivirus-mediated gene therapy significantly inhibited the growth of tumors compared with adenovirus-mediated gene therapy. Although adenovirus- and lentivirus-transduced Dm-dNK reveal strong treatment efficacy in vitro, the latter has great potential due to the long-term expression of the therapeutic gene in vivo.

Topics: Adenoviridae; Animals; Antineoplastic Agents; Apoptosis; Breast Neoplasms; Bromodeoxyuridine; Cell Line, Tumor; Cell Proliferation; Cell Survival; Combined Modality Therapy; Drosophila Proteins; Female; Gene Expression; Genetic Therapy; Genetic Vectors; HEK293 Cells; Humans; Lentivirus; Mice; Mice, Inbred BALB C; Mice, Nude; Phosphotransferases (Alcohol Group Acceptor); Prodrugs; Prohibitins; Tumor Burden; Xenograft Model Antitumor Assays

In the present paper we demonstrate that the cytostatic and antiviral activity of pyrimidine nucleoside analogues is markedly decreased by a Mycoplasma hyorhinis infection and show that the phosphorolytic activity of the mycoplasmas is responsible for this. Since mycoplasmas are (i) an important cause of secondary infections in immunocompromised (e.g. HIV infected) patients and (ii) known to preferentially colonize tumour tissue in cancer patients, catabolic mycoplasma enzymes may compromise efficient chemotherapy of virus infections and cancer. In the genome of M. hyorhinis, a TP (thymidine phosphorylase) gene has been annotated. This gene was cloned, expressed in Escherichia coli and kinetically characterized. Whereas the mycoplasma TP efficiently catalyses the phosphorolysis of thymidine (Km=473 μM) and deoxyuridine (Km=578 μM), it prefers uridine (Km=92 μM) as a substrate. Our kinetic data and sequence analysis revealed that the annotated M. hyorhinis TP belongs to the NP (nucleoside phosphorylase)-II class PyNPs (pyrimidine NPs), and is distinct from the NP-II class TP and NP-I class UPs (uridine phosphorylases). M. hyorhinis PyNP also markedly differs from TP and UP in its substrate specificity towards therapeutic nucleoside analogues and susceptibility to clinically relevant drugs. Several kinetic properties of mycoplasma PyNP were explained by in silico analyses.

Topics: Amino Acid Sequence; Antiviral Agents; Breast Neoplasms; Bromodeoxyuridine; Computational Biology; Female; Humans; Idoxuridine; Kinetics; Molecular Sequence Data; Mycoplasma hyorhinis; Mycoplasma Infections; Protein Conformation; Pyrimidine Nucleosides; Sequence Homology, Amino Acid; Substrate Specificity; Thymidine Phosphorylase; Tumor Cells, Cultured; Uridine Phosphorylase; Viruses

Deoxyribonucleoside kinase of Drosophila melanogaster (Dm-dNK) mutants have been reported to exert suicide gene effects in combined gene/chemotherapy of cancer. Here, we aimed to further evaluate the capacity of the mutanted enzyme and its potential for inhibiting cancer cell growth.. We altered the sequence of the last 10 amino acids of Dm-dNK to perform site-directed mutagenesis and constructed active site mutanted Dm-dNK (Dm-dNKmut), RT-PCR and western bloting studies were used to reveal the expression of lentivirus mediated Dm-dNKmut in a breast cancer cell line (Bcap37), a gastric cancer cell line (SGC7901) and a colorectal cancer cell line (CCL187). [3H]-labeled substrates were used for enzyme activity assays, cell cytotoxicity was assessed by MTT assays, cell proliferation using a hemocytometer and apoptosis induction by thenannexin-V-FITC labeled FACS method. In vivo, an animal study was set out in which BALB/C nude mice bearing tumors were treated with lentivirus mediated expression of Dm-dNKmut with the pyrimidine nucleoside analog brivudine (BVDU, (E)-5-(2-bromovinyl)-(2-deoxyuridine).. The Dm-dNKmut could be stably expressed in the cancer cell lines and retained its enzymatic activity. Moreover, the cells expressing Dm-dNKmut exhibited increased sensitivity in combination with BVDU, with induction of apoptosis in vitro and in vivo.. These findings underlined the importance of BVDU phosphorylated by Dm-dNKmut in transduced cancer cells and the potential role of Dm-dNKmut as a suicide gene, thus providing the basis for future intensive research for cancer therapy.

Topics: Amino Acid Sequence; Animals; Antiviral Agents; Apoptosis; Blotting, Western; Breast Neoplasms; Bromodeoxyuridine; Cell Proliferation; Colorectal Neoplasms; Combined Modality Therapy; Drosophila melanogaster; Female; Flow Cytometry; Genetic Therapy; Genetic Vectors; Humans; Lentivirus; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Mutagenesis, Site-Directed; Mutant Proteins; Mutation; Phosphotransferases (Alcohol Group Acceptor); Prohibitins; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sequence Homology, Amino Acid; Stomach Neoplasms; Tumor Cells, Cultured

The inhibitory effects of (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) and its arabinosyl derivative (E)-5-(2-bromovinyl)-1-beta-D-arabinofuranosyluracil (BVaraU) on the growth of both MDA-MB-435 human breast carcinoma and 9L rat gliosarcoma cells expressing the thymidine kinase (tk)-encoding gene of the Varicella zoster virus (VZV) or the Herpes simplex virus (HSV) were evaluated. In vitro, BVDU and BVaraU effectively killed both cell types expressing VZVtk, with 50% inhibitory concentration values ranging from 0.06 to 0.4 microM, whereas ganciclovir (GCV) lacked activity. On HSVtk+ cells, BVDU had high cytotoxic activity, with 50% inhibitory concentration values that were similar to those of GCV, whereas BVaraU was inactive. In vivo, BVDU applied intraperitoneally caused a 50% tumor growth inhibition in nude mice inoculated subcutaneously with VZVtk+ as well as HSVtk+ mammary tumor cells. In mice and at variance with the in vitro results, BVaraU had very little activity against the VZVtk+ mammary cells; GCV had the highest activity on the HSVtk+ cells, resulting in a 50% eradication of the tumors. With the 9L rat gliosarcoma model, the VZVtk/BVDU system completely failed to inhibit the development of VZVtk+ glioma tumors induced subcutaneously in syngeneic rats, although BVDU had a similar 45-minute half-life in both rats and mice. Factors other than degradation of the prodrug and related to the mode of action of these analogs are possibly involved in the observed discrepancies between the in vitro and in vivo results.

Topics: Animals; Antineoplastic Agents; Antiviral Agents; Arabinofuranosyluracil; Breast Neoplasms; Bromodeoxyuridine; Female; Genetic Vectors; Herpesvirus 3, Human; Humans; Male; Mice; Mice, Nude; Rats; Rats, Inbred F344; Simplexvirus; Thymidine Kinase; Tumor Cells, Cultured

To investigate the potential of the thymidine kinase gene from Varicella zoster virus (VZVtk) to act as a suicide gene, VZVtk was transferred via a dicistronic retroviral construct into MCF7, T-47D and MDA-MB-435 human breast cancer cells. The cytotoxicity of antiviral drugs was then evaluated in vitro on the wild-type and transduced cells. Acyclovir and ganciclovir did not show any selective toxicity for the modified cells. In contrast, (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) was extremely toxic for the VZVtk expressing cells, with IC50 values of 0.6 microM, 0.1 microM and 0.06 microM for MCF7, T-47D and MDA-MB-435 cells, respectively. The selectivity index of BVDU (ie the IC50 value ratio of the wild-type to the VZVtk cells) was 400 for MCF7, 750 for T-47D and 2000 for MDA-MB-435 cells. To test the system in vivo, VZVtk carrying MDA-MB-435 cells were inoculated subcutaneously into nude mice. An intraperitoneal treatment with BVDU administered at the emergence of the tumors, led to a prolonged arrest of the tumor growth and a reduced tumor mass. This effect was BVDU dose-dependent. No bystander effect of BVDU killing could be demonstrated in vitro on mixed populations of VZVtk positive and negative MDA-MB-435 cells. However, an important bystander effect was observed in identical experiments performed on 9L rat gliosarcoma cells infected with the VZVtk-carrying vector. These results demonstrate the efficiency of VZVtk as a suicide gene when BVDU is used as prodrug. The bystander effect measured in vitro, depends however on the tumoral cell type used.

Topics: 3T3 Cells; Animals; Antiviral Agents; Breast Neoplasms; Bromodeoxyuridine; Combined Modality Therapy; Female; Genetic Therapy; Genetic Vectors; Herpesvirus 3, Human; Humans; Mice; Mice, Nude; Rats; Thymidine Kinase; Tumor Cells, Cultured

Topics: Animals; Breast Neoplasms; Bromodeoxyuridine; Humans; Isoenzymes; Leukemia; Leukocytes, Mononuclear; Thymidine Kinase