Metabolism of the alpha,beta-unsaturated ketones, chalcone and trans-4-phenyl-3-buten-2-one, by rat liver microsomes and estrogenic activity of the metabolites.

When chalcone and trans-4-phenyl-3-buten-2-one (PBO) were incubated with liver microsomes of untreated rats in the presence of NADPH, 4-hydroxychalcone and trans-4-(4-hydroxyphenyl)-3-buten-2-one (4-OH-PBO), respectively, were formed as major metabolites. Two minor metabolites of chalcone, 4'-hydroxychalcone and 2-hydroxychalcone, were also observed. The oxidase activity affording 4-hydroxychalcone was inhibited by SKF 525-A, disulfiram, ketoconazole, and alpha-naphthoflavone. The oxidase activities leading to 4-hydroxychalcone and 4'-hydroxychalcone were enhanced in liver microsomes of 3-methylcholanthrene- and phenobarbital-treated rats, respectively. The activity generating 2-hydroxychalcone was enhanced in liver microsomes of 3-methylcholanthrene- and dexamethasone-treated rats. The oxidation of PBO to 4-OH-PBO was inhibited by SKF 525-A, ketoconazole, disulfiram, and sulfaphenazole. This activity was enhanced in liver microsomes of 3-methylcholanthrene-, acetone- and phenobarbital-treated rats. 4-Hydroxylation, 4'-hydroxylation, and 2-hydroxylation of chalcone were catalyzed by rat recombinant cytochrome P450 1A1, 1A2, and 2C6; by 1A1 and 2C6; and by 1A1 and 3A1, respectively. PBO was oxidized by cytochrome P450 1A1, 1A2, 2C6, and 2E1. Chalcone and PBO were negative in an estrogen reporter assay using estrogen-responsive human breast cancer cell line MCF-7. However, 4-hydroxychalcone, 2-hydroxychalcone, 4'-hydroxychalcone, and 4-OH-PBO exhibited estrogenic activity.     

Homepage of the Month

Homepages are redesigned or modified very frequently; therefore,please note that comments in this section are based on the contentsof the homepage at the time of writing. View larger version (64K): [in this window] [in a new window]     ISCT: The Professional Organization for those Working in Cell-basedResearch and Therapy (http://www.celltherapy.org/) Established in 1992, International Society for Cellular Therapy(ISCT), formerly International Society for Hematotherapy andGraft Engineering (ISHAGE),     

AdIκBα转染通过诱导凋亡逆转人非小细胞肺癌对泰素的耐药性

目的研究携带抑制性核因子κBα(IκBα)的腺病毒(AdIκBα)联合化疗对人非小细胞肺癌细胞株H460及H460荷瘤小鼠的作用。方法(1)检测50%抑制浓度(IC50)以确定化疗单用或联合AdIκBα对H460细胞增殖的影响,同时采用Annexin-V/PI染色法和caspase3活性测定来检测治疗引起的细胞凋亡情况;(2)观察泰素单用及联合不同浓度AdIκBα转染对H460荷瘤小鼠的作用,同时通过免疫组化染色观察核因子κB(NFκB)与p53及NFκB与血管内皮生长因子(VEGF)之间的关系。结果(1)联合AdIκBα3moi转染明显降低了泰素对H460的IC50,与激活caspase3途径而诱导了更多的细胞凋亡有关;在低剂量化疗组,联合治疗的疗效更加明显。(2)体内联合治疗明显抑制了H460荷瘤小鼠的肿瘤生长;免疫组化染色证实泰素治疗诱导了H460移植瘤细胞的NFκB表达增加,AdIκBα转染则消除了其表达,同时伴有轻度增加的VEGF表达,而p53表达不受影响。结论IκBα可通过阻滞NFκB表达和诱导凋亡而增加化疗疗效,同时减弱了VEGF表达,但与p53状态无关。推测联合治疗可减少化疗药的剂量,从而增加临床应用的耐受性。     

A multicenter phase II study of carboplatin and paclitaxel with a biweekly schedule in patients with advanced non-small-cell lung cancer: Kyushu thoracic oncology group trial

Purpose: This multicenter phase II study was conducted to investigate the efficacy and safety of carboplatin in combination with paclitaxel administered according to a biweekly schedule as a first-line chemotherapy for advanced non-small-cell lung cancer (NSCLC). Patients and methods: Eligibility criteria included histologically or cytologically confirmed NSCLC (stage IIIb or IV), no prior treatment, and measurable or evaluable disease. Paclitaxel (140 mg/m²) was administered intravenously on day 1, in combination with carboplatin at an area under the concentration time curve (AUC) of 3, every 2 weeks. Results: Seventy-four patients (45 men) with a median age of 62 years (range 40–74) and a median ECOG performance status of 1 (range 0–2) were enrolled. The response rate was 35.1% [95% confidence interval (CI): 24.4–47.1%], with 26 partial responses. The median survival was 357 days, and the median time to progression was 218 days. Toxicity was generally mild; National Cancer Institute-Common Toxicity Criteria (NCI-CTC) grades 3 and 4 neutropenia was observeded in 50.0% of the patients, and grades 3 and 4 nausea/vomiting in 4.1%. Conclusions: Biweekly carboplatin combined with paclitaxel demonstrated anti-tumor activity in advanced NSCLC, with response and survival rates similar to those of carboplatin combined with paclitaxel administered every 3 weeks but with a more favorable toxicity profile, and the present data indicate that the regimen is suitable for use on an outpatient basis.     

Ciliatamides A-C, bioactive lipopeptides from the deep-sea sponge Aaptos ciliata

Three lipopeptides, ciliatamides A-C ( 1- 3), were isolated from the deep-sea sponge Aaptos ciliata, and their structures were elucidated on the basis of spectroscopic and chemical methods. Ciliatamides A ( 1) and B ( 2) were found to be antileishmanial, while 2 also exhibited marginal cytotoxicity to HeLa cells.