Clin Cancer Res
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To determine the maximum tolerated dose and pharmacokinetics of Doxil in children with recurrent or refractory solid tumors. Doxil is pegylated doxorubicin. ⋯ The maximum tolerated dose of Doxil administered every 4 weeks to pediatric patients was 60 mg/m(2). The effect of Doxil on pediatric patients with malignancies remains to be determined and should be studied in pediatric Phase II trials.
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The c-Met receptor tyrosine kinase and its ligand HGF (hepatocyte growth factor) have been shown to be involved in angiogenesis, cellular motility, growth, invasion, and differentiation. The role of c-Met/HGF axis in small cell lung cancer (SCLC) has not been reported previously. We have determined the expression of p170(c-Met) precursor and p140(c-Met) beta-chain in seven SCLC cell lines by immunoblotting. ⋯ We also demonstrate that the Hsp90 inhibitor geldanamycin, which also affects c-Met, reduced the growth and viability of four of four SCLC cell lines by 25% to 85%, over a 72-h time period. Geldanamycin caused apoptosis of SCLC cells, as well as led to increased levels of Hsp70 but not Hsp90. These results demonstrate that c-Met/HGF pathway is functional in SCLC, and it would be useful to target this pathway toward novel therapy.
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Clinical Trial
A phase I and pharmacokinetic study of ecteinascidin-743 on a daily x 5 schedule in patients with solid malignancies.
The purpose of this study was to (a) assess the feasibility of administering ecteinascidin-743 (ET-743), a novel DNA minor-groove disrupting agent of marine origin, administered as a daily i.v. infusion for 5 days every 3 weeks; (b) recommend a dose for Phase II studies; (c) characterize its pharmacokinetic behavior; and (d) seek preliminary evidence of anticancer activity. ⋯ The maximum tolerated dose of ET-743 that can be administered repetitively is 325 microg/m(2)/day daily x 5 every 3 weeks, which is recommended for disease-directed clinical trials. The acceptable toxicity profile of ET-743 on the divided-dose schedule evaluated in this trial, as well as the generally superior antitumor activity associated with divided-dose schedules in preclinical studies, provides a rationale for further evaluation of ET-743 on this administration schedule.
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Angiogenesis plays a pivotal role in tumor growth and represents a key target for chemopreventive intervention. On the basis of the structural features and lack of target organ specificity of the synthetic dithiolethione oltipraz, inhibition of angiogenesis was assessed as a potential mechanism for its broad-based chemopreventive activity. The effects of oltipraz on the development and maturation of a vascular network was determined in vitro using two-dimensional capillary tube formation assays with human umbilical vein endothelial cells plated on Matrigel and ex vivo using primary rat aortic ring explant cultures in three-dimensional collagen gels, respectively. ⋯ The observed efficacy of oltipraz in this model is comparable with that of SU 5416 and TNP-470, known antiangiogenic agents currently under clinical development. Plasma levels of oltipraz at the termination of in vivo efficacy studies were 66.4 +/- 7 microM as determined by reversed phase high-performance liquid chromatography, a concentration range associated with significant antiangiogenic activity of oltipraz in vitro and ex vivo. These data suggest that the chemopreventive agent oltipraz may be effective in the treatment of advanced stage cancers and metastases, in part, because of its antiangiogenic activity in vivo.
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The traditional hormonal cascade of the 1970s and 1980s used tamoxifen followed by megestrol acetate and subsequently by aminoglutethimide. In the 1990s, however, three trials of third-generation aromatase inhibitors (AIs) compared with megestrol acetate and two trials of third-generation AIs compared with aminoglutethimide showed improved efficacy and decreased toxicity for the newer AIs. Thus, the hormonal cascade changed in the late 1990s, to one in which tamoxifen, followed by a third-generation AI, followed by megestrol acetate, seemed more suitable. ⋯ In addition, a randomized Phase II trial of 121 patients has shown nonsignificant benefits in favor of exemestane (RR 41% versus 14%; CB 56% versus 42%; TTP not available). To date, none of these trials has demonstrated any overall survival benefit. Additional follow-up in regard to survival in the trial of tamoxifen versus letrozole and an expanded Phase III trial of tamoxifen versus exemestane are ongoing.