Camptothecin
Mostrando 1-12 de 154 artigos, teses e dissertações.
-
1. Gene homozygosis and mitotic recombination induced by camptothecin and irinotecan in Aspergillus nidulans diploid cells
A recombinação mitótica é um processo com participação na carcinogênese e com capacidade de induzir perda genética através da perda da heterozigosidade. Os potenciais recombinagênicos de duas drogas anticancerígenas, camptotecina (CPT) e irinotecan (CPT-11), caracterizadas como inibidores da DNA-Topoisomerase I, foram avaliados no presente estudo,
An. Acad. Bras. Ciênc.. Publicado em: 21/10/2014
-
2. Effect of precursors feeding and media manipulation on production of novel anticancer pro-drug camptothecin from endophytic fungus
We have established methodology for the isolation and characterization of a novel endophytic fungus from the inner bark of medicinal plant Nothapodytes foetida, which produced camptothecin in Sabouraud broth (SB) under shake flask conditions. Camptothecin and its related compounds are at present obtained by extraction from intact plants, but fungal endopytes
Braz. J. Microbiol.. Publicado em: 2012-12
-
3. Synthesis and biological evaluation of novel conjugates of camptothecin and 5-flurouracil as cytotoxic agents
Uma série de novos conjugados de camptotecina e 5-fluorouracil foi sintetizada pela primeira vez e suas atividades citotóxicas contra duas linhagens de células humanas tumorais (SGC-7901 e A-549) assim como a determinação farmacocinética in vitro da estabilidade de lactona foram investigadas. Dentre estes compostos, a maioria apresentou atividades cito
Journal of the Brazilian Chemical Society. Publicado em: 2011-02
-
4. DESENVOLVIMENTO DE MÉTODOS ANALÍTICOS ESPECTROLUMINESCENTES E ELETROFORÉTICOS PARA A DETERMINAÇÃO DE ALCALOIDES (BETA-CARBOLINAS, CAMPTOTECINA E DERIVADOS) DE INTERESSE FARMACOLÓGICO / DEVELOPMENT OF ANALYTICAL METHODS BASED ON LUMINESCENCE AND ELECTROPHORESIS FOR THE DETERMINATION OF ALKALOIDS (BETA-CARBOLINES, CAMPTOTHECIN AND DERIVATIVES) OF PHARMACOLOGICAL INTEREST
Analytical methods were developed for the selective determination of alkaloids of pharmacological interest. Aiming the selective determination of camptothecin (CPT) in irinotecan (CPT-11) or topotecan (TPT) based pharmaceutical formulations, two spectrofluorimetric methods and one electrophoretic method with absorciometic detection were proposed. The spectro
Publicado em: 2009
-
5. Irinotecano ativa a via PI3-quinase/AKT/mTOR em linhagem de adenocarcinoma de colon / Chronic treatment with irinotecan activates the PI3K/AKT/mTOR pathway in HT-29 colon cancer xenografts
Resistance of tumors to chemotherapeutic agents is a common clinical problem in human cancer. Recently, the blocking of PI3-kinase signaling pathway was shown to enhance apoptosis induced by SN-38, an active form of irinotecan. To gain further insight into the molecular events of irinotecan-associated increase in PI3-kinase signaling pathway, aspirin and rap
Publicado em: 2007
-
6. Vias de inibição da apoptose em macrófagos J774 infectados com Leishmania (Leishmania) chagasi / Apoptosis inhibition pathways in J774 macrophages infected by Leishmania (L.) chagasi
Macrófagos infectados com Leishmania são protegidos de apoptose, entretanto não se conhece o mecanismo de transdução de sinal intracelular que interfere neste processo de morte. Neste trabalho, células J 774 em cultura, com privação de nutrientes, sofrem apoptose, a qual aumenta na presença dos indutores camptotecina (CPT) ou fator de necrose tumora
Publicado em: 2006
-
7. Sequence dependent modulating effect of camptothecin on the DNA-cleaving activity of the calf thymus type I topoisomerase.
High-resolution mapping of topol cleavages in the regions of human DNA including the oncogene c-Ha-ras and p53, has revealed three kinds of topol cleavage sites: cleavage sites not affected by camptothecin; cleavage sites reinforced only in the presence of camptothecin, and cleavage sites which weaken in the presence of camptothecin. Statistical analysis of
-
8. SCT1 mutants suppress the camptothecin sensitivity of yeast cells expressing wild-type DNA topoisomerase I.
Camptothecin is a potent antineoplastic agent that interferes with the action of eukaryotic DNA topoisomerase I; the covalent enzyme-DNA intermediate is reversibly stabilized, leading to G2 arrest and cell death. We used a genetic screen to identify cellular factors, other than DNA topoisomerase I, that participate in the process of camptothecin-induced cell
-
9. Antiviral Action of Camptothecin1
At a concentration of 10 μm, camptothecin inhibited vaccinia deoxyribonucleic acid (DNA) synthesis in HeLa cells. Inhibition of viral DNA synthesis was observed when the drug was added before infection or at 1 or 2 hr after infection. Inhibitory effects of camptothecin on vaccinia DNA synthesis could be reversed, even after exposure to the alkaloid for 2 hr
-
10. Induction of cleavage in topoisomerase I c-DNA by topoisomerase I enzymes from calf thymus and wheat germ in the presence and absence of camptothecin.
In this study, we further examined the sequence selectivity of camptothecin in mammalian topoisomerase I cDNA from human and Chinese hamster. In the absence of camptothecin, almost all the bases at the 3'-terminus of cleavage sites are T for calf thymus and wheat germ topoisomerase I. In addition, wheat germ topoisomerase I exhibits preference for C (or not
-
11. Ribosome Formation is Blocked by Camptothecin, a Reversible Inhibitor of RNA Synthesis
A new drug, camptothecin, has been used to study the regulation of ribosome synthesis in HeLa cells. 5 μM camptothecin inhibits the synthesis of heterogeneously sedimenting nuclear RNA by about 70%. Camptothecin also blocks a specific step in the processing of ribosomal precursor RNA, allowing the conversion of 45S RNA to 32S RNA, but inhibiting the convers
-
12. Comparison of In Vitro Activities of Camptothecin and Nitidine Derivatives against Fungal and Cancer Cells
The activities of a series of camptothecin and nitidine derivatives that might interact with topoisomerase I were compared against yeast and cancer cell lines. Our findings reveal that structural modifications to camptothecin derivatives have profound effects on the topoisomerase I-drug poison complex in cells. Although the water-soluble anticancer agents to
American Society for Microbiology.