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Camptothecin resistance

WebSep 11, 2007 · Camptothecin demonstrated strong anticancer activity in preliminary clinical trials but also low solubility and adverse drug reaction. Camptothecin is believed to be a … WebNational Center for Biotechnology Information

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WebOct 2, 2001 · Abstract. From the rat C6 glioma cell line in culture, we selected camptothecin-resistant variants by growth in the presence of increasing amounts of … WebMay 11, 2016 · Purpose Indenoisoquinolines are non-camptothecin topoisomerase I (TopI) inhibitors that overcome the limitations of camptothecins: chemical instability and camptothecin resistance. Two dosing schedules of the novel indenoisoquinoline, indotecan (LMP400), were evaluated in patients with advanced solid tumors. Methods … howard houserman https://teschner-studios.com

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WebIn this study, we established an SN-38-resistant cell line, PC-6/SN2-5, from the human oat cell carcinoma PC-6 cell line by a stepwise selection system, investigated the mechanism of resistance of this cell line and then compared the antitumor activity of camptothecin analogs against the cell line. WebDec 16, 2024 · Camptothecin derivatives are precursors of potent anticancer agents, but their biosynthesis remains largely unknown. ... D. et al. Induction of multiple pleiotropic drug resistance genes in yeast ... howard house lynn ma

RCSB PDB - 1RR8: Structural Mechanisms of Camptothecin …

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Camptothecin resistance

Topoisomerase I inhibitors: camptothecins and beyond - Nature

WebMay 13, 2015 · In continuation of our program aimed at the development of natural product-based pesticidal agents, three series of novel camptothecin derivatives were designed, synthesized, and evaluated for their biological activities against T. Cinnabarinus, B. brassicae, and B. xylophilus. All of the derivatives showed good-to-excellent activity … WebMar 31, 2016 · DNA topoisomerase I (Top1) is a DNA unwinding protein and the specific target of the camptothecin class of chemotherapeutic drugs. One of these, irinotecan, acting through its active metabolite SN-38, is used in the treatment of metastatic colorectal cancer. However, resistance to irinotecan represents a major clinical problem. Since …

Camptothecin resistance

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WebApr 13, 2024 · Irinotecan (SN-38) is a potent and broad-spectrum anticancer drug that targets DNA topoisomerase I (Top1). It exerts its cytotoxic effects by binding to the Top1-DNA complex and preventing the re-ligation of the DNA strand, leading to the formation of lethal DNA breaks. Following the initial response to irinotecan, secondary resistance is … WebThe mechanisms of resistance to CPT-11 in PC-7/CPT-11 cells were reduced conversion of CPT-11 to its active metabolite SN-38 and point mutation of topoisomerase I. Those in HAC-2/CPT-11 cells were reduction of topoisomerase I activity and decreased sensitivity of topoisomerase to topoisomerase I inhibitors.

WebOct 14, 2024 · (±)-Hypersines A–C (1–3), the three pairs of enantiomerically pure monoterpenoid polyprenylated acylphloroglucinols with an unprecedented 6/6/5/4 fused ring system, were isolated from Hypericum elodeoides. Their structures, including absolute configurations, were elucidated by comprehensive spectroscopic data, single-crystal X … WebDec 31, 2013 · Camptothecin (CPT) is a kind of quinoline alkaloid that has gained great attention due to its unique anti-tumor activities . Two semi-synthetic water-soluble …

WebJul 4, 2024 · Broad-spectrum resistance in cancer cells is often caused by the overexpression of ABC transporters; which varies across individuals because of genetic single-nucleotide polymorphisms (SNPs). In the present study; we focused on human ABCC4 and established cells expressing the wild-type (WT) or SNP variants of human … WebOct 7, 2016 · The camptothecins are a new class of chemotherapeutic agents which have a novel mechanism of action targeting the nuclear enzyme topoisomerase I. Knowledge of the structure-activity relationships of the parent compound camptothecin has led to the development of effective soluble analogues with manageable toxicities.

WebJan 10, 2024 · As camptothecin resistance in cancer is common, it will be interesting to test if p97 inhibition might also restore the cytotoxicity of camptothecin and prolong its efficacy. In summary,...

Webcamptothecin-resistant. The catalytic and structural dy-namical properties of a human DNA topoisomerase I mutant in which Ala-653 in the linker domain was mu-tated into Pro have been investigated. The mutant is resistant to camptothecin and in the absence of the drug displays a cleavage-religation equilibrium strongly shifted toward religation. how many ipv vaccines are neededWebApr 14, 2005 · Transfection of Bcl-2 into A549 cells induced a resistance to the short-term apoptotic effect triggered by 12459, suggesting that Bcl-2 is an important determinant for the activity of 12459. ... In contrast, the G-overhang degradation was not observed when apoptosis was induced by camptothecin. Bcl-2 overexpression did not modify the G … howard house nursing home kilmarnockWebApr 28, 2015 · Irinotecan is a camptothecin analogue currently used in clinical practice to treat advanced colorectal cancer. However, acquired resistance mediated by the drug efflux pump ABCG2 is a recognized problem. We reported on a novel camptothecin analogue, FL118, which shows anticancer activity superior to irinotecan. how many iranian drones does russia haveStudies have shown that substitution at position 7, 9, 10 and 11 can have positive effect on CPT activity and physical properties, e.g. potency and metabolic stability. Enlargement of the lactone ring by one CH 2 unit also enhances its abilities, as in homocamptothecin. Substitution at position 12 and 14 leads to inactive derivative. howard house richmondWebDec 1, 1999 · The present study describes camptothecin resistance and the potential for drug glucuronidation in two cell lines overexpressing the ABC half-transporter, … how many ira direct transfers per yearWebCamptothecin stabilizes a covalent enzyme-DNA intermediate that is converted into lethal double strand DNA lesions during S phase of the cell cycle. Yeast SCT1 mutants were … how many iq did albert einstein haveWebCamptothecin complexes with type I DNA topoisomerase inhibiting both cleavage and religation reactions of DNA replication thus arresting growth of L. donovani … how many iranians live in canada