Novel dual-reporter preclinical screen for antiastrocytoma agents identifies cytostatic and cytotoxic compounds.

Mouse Cancer Genetics Program, National Cancer Institute, Frederick, Maryland 21702, USA.
Journal of Biomolecular Screening (Impact Factor: 2.01). 08/2008; 13(8):795-803. DOI: 10.1177/1087057108321085
Source: PubMed

ABSTRACT Astrocytoma/glioblastoma is the most common malignant form of brain cancer and is often unresponsive to current pharmacological therapies and surgical interventions. Despite several potential therapeutic agents against astrocytoma and glioblastoma, there are currently no effective therapies for astrocytoma, creating a great need for the identification of effective antitumor agents. The authors have developed a novel dual-reporter system in Trp53/Nf1-null astrocytoma cells to simultaneously and rapidly assay cell viability and cell cycle progression as evidenced by activity of the human E2F1 promoter in vitro. The dual-reporter high-throughput assay was used to screen experimental therapeutics for activity in Trp53/Nf1-null astrocytoma. Several compounds were identified demonstrating selectivity for astrocytoma over primary astrocytes. The dual-reporter system described here may be a valuable tool for identifying potential antitumor treatments that specifically target astrocytoma.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A neurofibromatosis type 1 (NF1) based bioassay-guided phytochemical investigation on Simarouba berteroana led to the isolation of one new canthin-6-one-9-methoxy-5-O-β-d-glucopyranoside (1), seven known canthine alkaloids (2–8), two known quassinoids (9–10) and a known neo-lignan (11). The structures of all compounds were established by HRMS, 1D- and 2D NMR analysis and comparison with previously reported data. Most of the compounds inhibited the proliferation of an Nf1- and p53-deficient mouse glioma cell line at non-cytotoxic concentrations.
    Phytochemistry Letters 02/2014; 7:42–45. DOI:10.1016/j.phytol.2013.09.007 · 1.54 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Neurofibomatosis (NF1) patients are susceptible to multiple tumors of the nervous system including neurofibromas, optic glioma, malignant peripheral nerve sheath tumors (MPNSTs), and astrocytoma. The Nf1+/-;Trp53+/- (NPcis) mouse model of NF1 spontaneously develops astrocytoma and MPNSTs that are very similar to human NF1 tumors. To use this model for testing potential therapeutics, we have developed systems that take advantage of bioluminescent reporters of tumor growth. We have generated E2F1 promoter-driving luciferase (ELUX) reporter mice to detect proliferating tumors in NPcis mice in vivo using bioluminescence. The power of this system is that it enables looking at tumor evolution and detecting spontaneous tumors at early stages of development as they evolve within their natural haploinsufficient microenvironment. This system can be used to identify tumors at different stages of tumorigenesis and to examine where spontaneous NF1 tumors initiate. The ability to rapidly screen multiple animals at a time increases the potential for use of this model in preclinical trials. This model will be valuable for the characterization of spontaneous NF1 tumors and will be important for studying the treatment and prevention of NF1 tumors in vivo.
    Toxicologic Pathology 02/2010; 38(1):123-30. DOI:10.1177/0192623309357075 · 1.92 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The overall objective of this project was to discover, design and demonstrate the feasibility of bioluminescent materials for use in marking, tagging, and anti-tamper applications. Five major accomplishments were completed. (1) The feasibility of performing dual analyte reporter gene assays in mammalian cells grown at 37 C with thermostable red and green light-emitting mutants of firefly luciferase was demonstrated. (2) The gene for Ppy RE9, a novel thermostable red-light emitting firefly luciferase variant, was human codon optimized. The gene provided ~100-fold greater signal intensity than a commercial genetic reporter in a human cell line. (3) Mutagenesis studies of luciferase identified residues responsible for blue-shifted emission, pH and thermal stability. (4) A red-emitting luciferase variant Ppy RE10 was selectively labeled with near IR fluorescent dyes. Through the BRET process, the enzymes produced light with maxima at 705 nm or 778 nm. Fusion proteins containing these labeled enzymes were made and immobilized onto magnetic microspheres. (5) A fluorescent chlorophyll a derivative was isolated from the worm C. variopedatus. Also, mass spectral studies of a small molecule fraction of O. phosphorea mucous advanced the structure identification of a putative bioluminescence stimulating factor.