Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.3.1.21 (CPT)
 4,580 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Water-soluble derivatives of camptothecin, and active topoisomerase I inhibitor, have shown a broad spectrum of activity against human tumors. Early clinical trials with the water-soluble sodium salt of camptothecin were hindered by significant cystitis, gastroenteritis, and leukopenia. Furthermore, the sodium salt of camptothecin has been shown to have significantly less activity than the water-insoluble lactone form of the compound. We describe a formulation of lipid-complexed CPT (LC-CPT; particle size range 20.8-208.1 nm) that is very easy to prepare and allows for intravenous administration in vivo in clinically relevant lipid-drug ratios (12.5:1 w/w). The lipid formulation had in vitro antitumor activity similar to that of CPT formulated without lipids and displayed similar cytotoxicity against MDR-1-negative and -positive tumor cells. The biodistribution of CPT was profoundly affected by lipid complexation; free CPT achieved the greatest concentration in the pulmonary parenchyma while LC-CPT achieved the highest concentration in the gastrointestinal tract. LC-CPT had significant antitumor activity in vivo against intraperitoneal L1210 and P338 leukemia and appeared to be more potent then free CPT.
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PMID:Lipid-complexed camptothecin: formulation and initial biodistribution and antitumor activity studies. 861 6

TAS-103 is a novel anticancer agent targeting both topoisomerase (Topo) I and Topo II, that stabilizes cleavable complexes of Topo-DNA at the cellular level. In this study, the in vitro antitumor effects of TAS-103 were compared with those of other known Topo I and Topo II inhibitors. TAS-103 inhibited DNA synthesis more strongly than RNA and protein synthesis, and induced an increase of cell population in the S-G2/M phase. The cytotoxicity of TAS-103 was strongest against S-phase cells, but its cell cycle phase specificity was not clear, and depended on drug concentration and exposure time. The cytotoxicity of TAS-103 (IC50: 0.0030-0.23 microM) against various tumor cell lines was much stronger than that of VP-16 and comparable to that of SN-38. The cytotoxicity of TAS-103 seemed to be more related to the amount of protein-DNA complexes than to the accumulation of TAS-103 in the cells. P-Glycoprotein (P-gp)-mediated MDR, CDDP-resistant and 5-FU-resistant cell lines did not show cross-resistance to TAS-103. Although PC-7/CPT cells bearing a Topo I gene mutation showed cross-resistance to TAS-103, the sensitivity of P388/CPT, HT-29/CPT and St-4/CPT cells, showing decreased Topo I expression, was not changed. KB/VM4 and HT-29/Etp cells, showing decreased Topo II expression, were slightly cross-resistant to TAS-103. These results suggest that TAS-103 may act as an inhibitor of both Topo I and Topo II at the cellular level. This property may be responsible for its strong antitumor effect and broad-spectrum, growth-inhibitory effect on drug-resistant cell lines.
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PMID:In vitro antitumor activity of TAS-103, a novel quinoline derivative that targets topoisomerases I and II. 1039 Oct 99

Albumin concentration and body weight are altered in patients with multidrug-resistant tuberculosis (MDR-TB) and change during the long treatment period, potentially affecting drug disposition. We here describe the pharmacokinetics (PKs) of the novel anti-TB drug bedaquiline and its metabolite M2 in 335 patients with MDR-TB receiving 24 weeks of bedaquiline on top of a longer individualized background regimen. Semiphysiological models were developed to characterize the changes in weight and albumin over time. Bedaquiline and M2 disposition were well described by three and one-compartment models, respectively. Weight and albumin were correlated, typically increasing after the start of treatment, and significantly affected bedaquiline and M2 plasma disposition. Additionally, age and race were significant covariates, whereas concomitant human immunodeficiency virus (HIV) infection, sex, or having extensively drug-resistant TB was not. This is the first population model simultaneously characterizing bedaquiline and M2 PKs in its intended use population. The developed model will be used for efficacy and safety exposure-response analyses.
CPT Pharmacometrics Syst Pharmacol 2016 12
PMID:Population Pharmacokinetics of Bedaquiline and Metabolite M2 in Patients With Drug-Resistant Tuberculosis: The Effect of Time-Varying Weight and Albumin. 2786 79