Gene Therapy with p14/tBID Induces Selective and Synergistic Apoptosis in Mutant Ras and Mutant p53 Cancer Cells In Vitro and In Vivo.

Any gene therapy for cancer will be predicated upon its selectivity against cancer cells and non-toxicity to normal cells. Therefore, safeguards are needed to prevent its activation in normal cells. We designed a minimal p14 promoter with upstream Ap1 and E2F enhancer elements and a downstream MDR1 inhibitory element, TATA box, and a transcription initiation site (hereafter p14min).

C-Terminal p53 Palindromic Tetrapeptide Restores Full Apoptotic Function to Mutant p53 Cancer Cells In Vitro and In Vivo.

We previously demonstrated that a synthetic monomer peptide derived from the C-terminus of p53 (aa 361−382) induced preferential apoptosis in mutant p53 malignant cells, but not normal cells. The major problem with the peptide was its short half-life (half-life < 10 min.) due to a random coil topology found in 3D proton NMR spectroscopy studies.

Magnetic resonance imaging of major histocompatibility class II expression in the renal medulla using immunotargeted superparamagnetic iron oxide nanoparticles.

We demonstrate the development and successful application of immunotargeted superparamagnetic iron oxide nanoparticles (ITSIONs), with in vivo magnetic resonance diagnostic and potential drug delivery capability for kidney disease. Further, the versatility of the conjugation chemistry presents an attractive route to the preparation of a range of biomolecule-nanoparticle conjugates. The ITSION contrast agent is a stable, biocompatible, targeted nanoparticle complex that combines a monodisperse iron oxide nanoparticle core with a functionalized phospholipid coating conjugated to antibodies that is capable of targeting normal cells expressing specific target antigens.

Novel hypoglycemic dihydropyridones serendipitously discovered from O- versus C-alkylation in the synthesis of VMAT2 antagonists.

Vesicular monoamine transporter type 2 (VMAT2) is a newly emerging target for both diagnostic and therapeutic applications in diabetes mellitus. In pursuit of novel VMAT2 antagonists, we identified a potent hypoglycemic agent with a novel dihydropyridone scaffold. Several analogs were designed and synthesized.

Role of vesicular monoamine transporter type 2 in rodent insulin secretion and glucose metabolism revealed by its specific antagonist tetrabenazine.

Despite different embryological origins, islet beta-cells and neurons share the expression of many genes and display multiple functional similarities. One shared gene product, vesicular monoamine transporter type 2 (VMAT2, also known as SLC18A2), is highly expressed in human beta-cells relative to other cells in the endocrine and exocrine pancreas. Recent reports suggest that the monoamine dopamine is an important paracrine and/or autocrine regulator of insulin release by beta-cells.

Visualizing pancreatic beta-cell mass with [11C]DTBZ.

Beta-cell mass (BCM) influences the total amount of insulin secreted, varies by individual and by the degree of insulin resistance, and is affected by physiologic and pathologic conditions. The islets of Langerhans, however, appear to have a reserve capacity of insulin secretion and, overall, assessments of insulin and blood glucose levels remain poor measures of BCM, beta-cell function and progression of diabetes. Thus, novel noninvasive determinations of BCM are needed to provide a quantitative endpoint for novel therapies of diabetes, islet regeneration and transplantation.

Longitudinal noninvasive PET-based beta cell mass estimates in a spontaneous diabetes rat model.

Diabetes results from an absolute or relative reduction in pancreatic beta cell mass (BCM) leading to insufficient insulin secretion and hyperglycemia. Measurement of insulin secretory capacity is currently used as a surrogate measure of BCM. However, serum insulin concentrations provide an imprecise index of BCM, and no reliable noninvasive measure of BCM is currently available.

Antisense RNA down-regulation of bcl-2 expression in DU145 prostate cancer cells does not diminish the cytostatic effects of G3139 (Oblimersen).

Purpose: Inhibition of the function of the bcl-2 protein has been postulated to sensitize cells to cytotoxic chemotherapy, and thus provides an attractive target for investigative therapies. G3139, a phosphorothioate antisense oligonucleotide targeted to the initiation codon region of the bcl-2 mRNA, is currently being evaluated in several Phase II and Phase III clinical trials. However, the mechanism of action of this molecule appears to depend on a combination of antisense plus nonantisense events.

Fas-mediated apoptosis is dependent on wild-type p53 status in human cancer cells expressing a temperature-sensitive p53 mutant alanine-143.

The p53 mutant 143Ala is a human temperature-sensitive mutant with two conformational states. To definitively determine whether the Fas signal transduction pathway and the function of the pathway are dependent on p53 status, we have established stable transfectants of p53 mutant 143Ala in two human cancer cell lines: H1299 (lung cancer line) and PC-3 (prostate cancer line), the native state of which contains null p53 status and can grow at 37 degrees C and 32.5 degrees C.

Preferential induction of necrosis in human breast cancer cells by a p53 peptide derived from the MDM2 binding site.

p53 is the most frequently altered gene in human cancer and therefore represents an ideal target for cancer therapy. Several amino terminal p53-derived synthetic peptides were tested for their antiproliferative effects on breast cancer cell lines MDA-MB-468 (mutant p53), MCF-7 (overexpressed wild-type p53), and MDA-MB-157 (null p53). p53(15)Ant peptide representing the majority of the mouse double minute clone 2 binding site on p53 (amino acids 12-26) fused to the Drosophila carrier protein Antennapedia was the most effective.

Antisense RNA down-regulation of bcl-xL Expression in prostate cancer cells leads to diminished rates of cellular proliferation and resistance to cytotoxic chemotherapeutic agents.

bcl-xL is a M(r) 26,000 bcl-2 homologue that is highly expressed in prostate cancer cells. In previous studies, the down-regulation of its expression by antisense oligonucleotides led to resistance. In this work, the 445-bp 5' terminus of the bcl-xL cDNA was cloned in the antisense orientation and stably transfected into DU145 and LNCaP prostate cancer cells.