A phase I and pharmacokinetic study of the nonpolyglutamatable thymidylate synthase inhibitor ZD9331 plus docetaxel in patients with advanced solid malignancies

PURPOSE: To assess the feasibility of administering ZD9331, a thymidylate synthase (TS) inhibitor that does not undergo polyglutamation and has broad antitumor activity, in combination with docetaxel in patients with advanced solid malignancies. The study also sought to determine the principal toxicities of the regimen and recommend appropriate doses for phase II studies, characterize the pharmacokinetics of the agents, evaluate the possibility of major drug-drug interactions, and seek preliminary evidence of anti-cancer activity. PATIENTS AND METHODS: Patients with advanced solid malignancies were treated with escalating doses of docetaxel as a 60-minute intravenous (IV) infusion followed 30 minutes later by ZD9331 as a 30-minute IV infusion every 3 weeks. At least three patients were treated at each dose level, and the maximum tolerated dose level was defined as the highest dose level that was not associated with an unacceptably high incidence of severe toxicity. The pharmacokinetics of both ZD9331 and docetaxel were also characterized. RESULTS: Nineteen patients were treated with 71 cycles of ZD9331 and docetaxel (ZD9331/docetaxel) at dose levels that encompassed dosing iterations of ZD9331 ranging from 65 to 260 mg/m(2) and docetaxel doses in the range of 50 to 75 mg/m(2). Neutropenia was the principal toxicity of the ZD9331/docetaxel regimen. Since five of six patients treated at the ZD9331/docetaxel dose-level of 260/60 mg/m(2) had grade 4 neutropenia that was brief and uncomplicated in the first course, a rigorous exploration of higher dose levels was not undertaken. Nonhematologic toxicities, consisting of malaise, diarrhea, rash, nausea, and vomiting, were also observed, but these effects were rarely severe. No major antitumor responses were observed. The pharmacokinetics of both ZD9331 and docetaxel were similar to those reported in previous studies of each agent administered alone, suggesting the lack of major drug-drug interactions. CONCLUSION: The combination regimen, consisting of ZD9331 and docetaxel, is feasible and well tolerated at single-agent doses that are clinically-relevant. This ZD9331/docetaxel regimen does not appear to be associated with either major pharmacokinetic or toxicologic drug-drug interactions. A ZD9331/docetaxel dose level of 260/60 mg/m(2) is recommended as an initial dose level in disease-directed studies of the regimen, with further dose escalation of docetaxel to 75 mg/m(2) if the initial treatment is well tolerated. Further studies with this regimen are warranted in tumor types that have demonstrated sensitivity to both agents.     

Spatio-temporal distribution of microglia/macrophages during regeneration in the cerebellum of adult teleost fish,Apteronotus leptorhynchus: a quantitative analysis

In contrast to mammals, adult teleost fish exhibit an enormous capacity to replace damaged neurons with newly generated ones after injuries in the central nervous system. In the present study, the role of microglia/macrophages, identified by tomato lectin binding, was examined in this process of neuronal regeneration in the corpus cerebelli of the teleost fish Apteronotus leptorhynchus. In the intact corpus cerebelli, or after short survival times following application of a mechanical lesion to this cerebellar subdivision, microglia/macrophages were virtually absent. Conversely, approximately 3 days after application of the lesion, the areal density of microglia/macrophages started to increase at and near the lesion site in the ipsilateral hemisphere, as well as in the contralateral hemisphere, and reached maximum levels at approximately 10 days post lesion. The density remained elevated until it reached background levels approximately one month after the injury. By comparing the time course of the appearance of microglia/macrophages with that of other regenerative events occurring within the first few weeks of wound healing in this model system, we hypothesize that one possible function of microglia/macrophages might be to remove debris of cells that have undergone apoptotic cell death at the lesion site.     

Acute intracerebroventricular administration of either carboxyl-terminal or amino-terminal fragments of agouti-related peptide produces a long-term decrease in energy expenditure in rats

We investigated if agouti-related peptide (AgRP), an endogenous antagonist of melanocortin receptors (MC3-R and MC4-R), effects energy expenditure in rats. Fragments of the carboxyl-terminal, AgRP (83-132), and the amino-terminals, AgRP (25-51) and AgRP (54-82), were administered intracerebroventricularly (ICV). Food intake, body weight and fat weight changes were measured 5 and/or 24 h after a single ICV injection of the fragments. Oxygen consumption and colonic temperature were measured as indices of energy expenditure, during 3 and 24 h after the ICV injections, respectively. An oral glucose tolerance test was performed 24 h after ICV AgRP (83-132) injection. Binding experiments were performed in HEK-293 cells that over-expressed human MC4-R. AgRP (83-132), but not AgRP (25-51) nor AgRP (54-82), induced a potent and long-lasting increase in the cumulative food intake. Both the carboxyl-terminal and amino-terminal AgRP fragments significantly decreased oxygen consumption and colonic temperature. Despite the absence of hyperphagia and cross-reactivities with MC4-R, AgRP (25-51) and AgRP (54-82) significantly increased body weight and epididymal/mesenteric fat weight. AgRP (83-132) did not affect glucose and insulin responses to the oral glucose tolerance test. AgRP causes a potent and long-lasting decrease in energy expenditure; an effect that is exhibited by carboxyl-terminal fragments and amino-terminal fragments that lack antagonist activity at the MC receptors. This suggests that the amino-terminal region of AgRP plays a regulatory role in energy metabolism.     

Chemical chaperone therapy for brain pathology in G(M1)-gangliosidosis

We synthesized a galactose derivative, N-octyl-4-epi-beta-valienamine (NOEV), for a molecular therapy (chemical chaperone therapy) of a human neurogenetic disease, beta-galactosidosis (GM1-gangliosidosis and Morquio B disease). It is a potent inhibitor of lysosomal beta-galactosidase in vitro. Addition of NOEV in the culture medium restored mutant enzyme activity in cultured human or murine fibroblasts at low intracellular concentrations, resulting in a marked decrease of intracellular substrate storage. Short-term oral administration of NOEV to a model mouse of juvenile GM1-gangliosidosis, expressing a mutant enzyme protein R201C, resulted in significant enhancement of the enzyme activity in the brain and other tissues. Immunohistochemical stain revealed a decrease in the amount of GM1 and GA1 in neuronal cells in the fronto-temporal cerebral cortex and brainstem. However, mass biochemical analysis did not show the substrate reduction observed histochemically in these limited areas in the brain probably because of the brief duration of this investigation. Chemical chaperone therapy may be useful for certain patients with beta-galactosidosis and potentially other lysosomal storage diseases with central nervous system involvement.     

Three-dimensional fusion imaging of lymphoscintigraphy and MDCT for sentinel node biopsy in breast cancer

The purpose of this study was to evaluate the clinical usefulness of three-dimensional (3D) fusion imaging of lymphoscintigraphy with 99mTc phytate and MDCT (four-slice CT) for sentinel node biopsy in breast cancer. Volume-rendering images generated by MDCT were fused with lymphoscintigrams on a personal computer. The subjects were 7 patients with clinically negative nodes. In all patients, sentinel nodes were identified by lymphoscintigraphy, and the anatomical locations of sentinel nodes were clearly demonstrated by 3D-fusion imaging. 3D-fusion imaging of lymphoscintigraphy and MDCT is expected to be a promising method for sentinel node biopsy in breast cancer.     

Suppressive effect of modified dominant negative RAS mutant on human cancer by gene transfer with non-viral vector

N116Y, H-RAS mutant, has dominant negative activity in the RAS function and a suppressive effect on the growth of various types of cancer cells. However, a replication error of N116Y is of potential concern for carcinogenesis in clinical application. To decease the concern, we constructed modified N116Y by deleting the carboxyl terminus, which is necessary for the oncogenic function of Ras. One of the C-terminal deletion mutants of N116Y, N116Y-Cdel2 showed a growth-suppressing effect on various human cancer cell lines in vitro: the cervical cancer cell line HeLa, the pancreatic cancer cell line PCI43, the colon cancer cell lines SW480 and LoVo, and the tongue cancer cell line SAS. In addition, the suppressive effect of N116Y-Cdel2 on LoVo cells was also observed in vivo using a nonviral gene transfer vector, HVJ envelope. Our experiments suggest that the modified N116Y is a potential candidate gene for human cancer gene therapy.