Inhibition of furin/proprotein convertase-catalyzed surface and intracellular processing by small molecules.

Furin is a ubiquitously expressed proprotein convertase (PC) that plays a vital role in numerous disease processes including cancer metastasis, bacterial toxin activation (e.g. anthrax and Pseudomonas), and viral propagation (e.

Noninvasive imaging of apoptosis and its application in cancer therapeutics.

Purpose: Activation of the apoptotic cascade plays an important role in the response of tumors to therapy. Noninvasive imaging of apoptosis facilitates optimization of therapeutic protocols regarding dosing and schedule and enables identification of efficacious combination therapies.

Experimental Design: We describe a hybrid polypeptide that reports on caspase-3 activity in living cells and animals in a noninvasive manner.

A small-molecule furin inhibitor inhibits cancer cell motility and invasiveness.

Furin, a member the proprotein convertase (PC) family, processes inactive precursor proteins to functional proteins within the Golgi/trans-Golgi network secretory pathway. Furin and other PC family members (furin/PCs) activate proteins vital to proper physiological functioning, including growth factors and hormones, receptors, plasma proteins, and matrix metalloproteases (MMPs). Additionally, the expression and activity of furin/PC are necessary for processing substrates important for cell transformation and tumor progression, metastasis, and angiogenesis.

Identification of inhibitors using a cell-based assay for monitoring Golgi-resident protease activity.

Noninvasive real-time quantification of cellular protease activity allows monitoring of enzymatic activity and identification of activity modulators within the protease's natural milieu. We developed a protease activity assay based on differential localization of a recombinant reporter consisting of a Golgi retention signal and a protease cleavage sequence fused to alkaline phosphatase (AP). When expressed in mammalian cells, this protein localizes to Golgi bodies and, on protease-mediated cleavage, AP translocates to the extracellular medium where its activity is measured.

Imaging of proteolytic activity using a conditional cell surface receptor.

Programmed cell death (apoptosis) is a ubiquitous means utilized by multicellular organisms for elimination of unwanted cells during development and homeostasis. Dysregulated apoptosis is implicated in an array of clinical disorders including cancer, autoimmune diseases, neurodegenerative disorders, and ischemia. During programmed cell death, a series of proteases, known as caspases, with different specificities play crucial roles in the apoptotic process.

Phosphorylated FADD induces NF-kappaB, perturbs cell cycle, and is associated with poor outcome in lung adenocarcinomas.

In an effort to identify a clinical biomarker for lung cancer, we used cDNA microarray and 2D protein analyses to demonstrate that increased Fas-associated death domain (FADD) mRNA and protein were significantly associated with poor survival. Analyses of copy number and sequence of the FADD gene in 24 independent tumors ruled out the existence of an amplified and/or mutated FADD gene in aggressive lung cancers. Immunohistochemistry-based tissue microarray analysis showed that nuclear localization of FADD and elevation of the phosphorylated form of FADD (p-FADD) correlated with poor outcome (P = 0.