Showing papers by "Shinae Kizaka-Kondoh published in 2006"

Thioredoxin-Binding Protein-2-Like Inducible Membrane Protein Is a Novel Vitamin D3 and Peroxisome Proliferator-Activated Receptor (PPAR)γ Ligand Target Protein that Regulates PPARγ Signaling

Abstract: Thioredoxin binding protein-2 (TBP-2), which is identical with vitamin D3 (VD3) up-regulated protein 1 (VDUP1), plays a crucial role in the integration of glucose and lipid metabolism. There are three highly homologous genes of TBP-2/vitamin D3 up-regulated protein 1 in humans, but their functions remain unclear. Here we characterized a TBP-2 homolog, TBP-2-like inducible membrane protein (TLIMP). In contrast to TBP-2, TLIMP displayed no significant binding affinity for thioredoxin. TLIMP exhibited an inner membrane-associated pattern of distribution and also colocalized with transferrin and low-density lipoprotein, indicating endosome- and lysosome-associated functions. VD3 and ligands of peroxisome proliferator-activated receptor (PPAR)-γ, an important regulator of energy metabolism and cell growth inhibition, induced the expression of TLIMP as well as TBP-2. Overexpression of TLIMP suppressed both anchorage-dependent and -independent cell growth and PPARγ ligand-inducible gene activation. These results...

Antitumor Protein Therapy; Application of the Protein Transduction Domain to the Development of a Protein Drug for Cancer Treatment

Abstract: The genomic information obtained through the human genome project has been accelerating the analysis of the functions of various disease relevant genes. The high molecular weight biomolecules, including oligonucleotides, antisense nucleotides, small interference RNA and peptides, as well as genes (cDNA) and proteins, are becoming increasingly important for the development of molecular therapies. However, the potential of such information-rich macromolecules for therapeutic use has been limited by the poor permeability across the lipid bilayer of the cellular plasma membrane. Over the past decade, a unique activity of oligopeptides, known as protein transduction domains (PTDs) or cell penetrating peptides (CPPs), has made it possible to transduce biologically active macromolecules into living cellsin vitro by conjugating a PTD to the desired macromolecule. Furthermore, this activity has also enabled the systemic delivery of bioactive macromolecules to all tissues in living animals. However, we are now confronted with the next difficulty delivering the macromolecules specifically to the therapeutic targetsin vivo. In this review, we focus on the application of PTD to develop antitumor macromolecules and introduce several representative strategies to discriminate between tumor and normal tissue. In addition, we discuss the unique characteristics of breast cancer, which are expected to facilitate the application of PTD to develop novel protein therapy for breast cancer.

Suppression of VEGF transcription in renal cell carcinoma cells by pyrrole-imidazole hairpin polyamides targeting the hypoxia responsive element

Abstract: Hypoxia inducible factor (HIF), a master regulator of critical genes for cell survival under hypoxic conditions, is known to be related to tumorigenesis and progression of renal cell carcinoma. N-methylpyrrole (Py)-N-methylimidazole (Im) hairpin polyamides are synthetic organic compounds that recognize and bind to the minor grooves of specific DNA sequences. We synthesized three Py-Im hairpin polyamides targeting the flanking sequences of hypoxia responsive element (HRE; a binding site of HIF) in the promoter region of the vascular endothelial growth factor (VEGF) gene. The effects of the polyamides on HIF-induced transcription were evaluated by a luciferase assay using a reporter plasmid containing a VEGF promoter. Real time reverse-transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay were performed to examine the effects of the polyamides on the transcription and secretion of VEGF in A498 renal cell carcinoma cells, which have a frame-shift mutation in the von Hippel-Lindau gene. A combination of three Py-Im hairpin polyamides suppressed HIF-induced transcription in reporter assays using 293 cells and successfully suppressed transcription and translation of the VEGF gene in A498 cells. Inhibition of the HIF-HRE interaction was confirmed by an electrophoresis mobility shift assay. An approach using Py-Im hairpin polyamides may be a new strategy for the treatment of renal cell carcinoma.