Exposure and Tumor Fn14 Expression as Determinants of Pharmacodynamics of the Anti-TWEAK Monoclonal Antibody RG7212 in Patients with Fn14-Positive Solid Tumors.

Purpose: The TWEAK-Fn14 pathway represents a novel anticancer target that is being actively investigated. Understanding the relationship between pharmacokinetics of anti-TWEAK therapeutics and tumor pharmacodynamics is critical. We investigated exposure-response relationships of RG7212, an anti-TWEAK mAb, in patients with Fn14-expressing tumors.

A phase I monotherapy study of RG7212, a first-in-class monoclonal antibody targeting TWEAK signaling in patients with advanced cancers.

Purpose: Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) and fibroblast growth factor-inducible molecule 14 (Fn14) are a ligand-receptor pair frequently overexpressed in solid tumors.

Tweak: Fn14 signaling regulates multiple oncogenic processes through MAPK, AKT, and NFκB pathway activation. A phase I study of RG7212, a humanized anti-TWEAK IgG1κ monoclonal antibody, was conducted in patients with advanced solid tumors expressing Fn14.

RG7212 anti-TWEAK mAb inhibits tumor growth through inhibition of tumor cell proliferation and survival signaling and by enhancing the host antitumor immune response.

Purpose: To explore the role of TWEAK in tumor growth and antitumor immune response and the activity and mechanism of RG7212, an antagonistic anti-TWEAK antibody, in tumor models.

Experimental Design: TWEAK-induced signaling and gene expression were explored in tumor cell lines and inhibition of these effects and antitumor efficacy with RG7212 treatment was assessed in human tumor xenograft-, patient-derived xenograft, and syngeneic tumor models and phase I patients. Genetic features correlated with antitumor activity were characterized.

Effect of the MDM2 antagonist RG7112 on the P53 pathway in patients with MDM2-amplified, well-differentiated or dedifferentiated liposarcoma: an exploratory proof-of-mechanism study.

Background: We report a proof-of-mechanism study of RG7112, a small-molecule MDM2 antagonist, in patients with chemotherapy-naive primary or relapsed well-differentiated or dedifferentiated MDM2-amplified liposarcoma who were eligible for resection.

Methods: Patients with well-differentiated or dedifferentiated liposarcoma were enrolled at four centres in France. Patients received up to three 28-day neoadjuvant treatment cycles of RG7112 1440 mg/m(2) per day for 10 days.

A portrait of tissue phosphoprotein stability in the clinical tissue procurement process.

Little is known about the preanalytical fluctuations of phosphoproteins during tissue procurement for molecular profiling. This information is crucial to establish guidelines for the reliable measurement of these analytes. To develop phosphoprotein profiles of tissue subjected to the trauma of excision, we measured the fidelity of 53 signal pathway phosphoproteins over time in tissue specimens procured in a community clinical practice.

Smart hydrogel particles: biomarker harvesting: one-step affinity purification, size exclusion, and protection against degradation.

Disease-associated blood biomarkers exist in exceedingly low concentrations within complex mixtures of high-abundance proteins such as albumin. We have introduced an affinity bait molecule into N-isopropylacrylamide to produce a particle that will perform three independent functions within minutes, in one step, in solution: (a) molecular size sieving, (b) affinity capture of all solution-phase target molecules, and (c) complete protection of harvested proteins from enzymatic degradation. The captured analytes can be readily electroeluted for analysis.

Laser-capture microdissection.

Deciphering the cellular and molecular interactions that drive disease within the tissue microenvironment holds promise for discovering drug targets of the future. In order to recapitulate the in vivo interactions thorough molecular analysis, one must be able to analyze specific cell populations within the context of their heterogeneous tissue microecology. Laser-capture microdissection (LCM) is a method to procure subpopulations of tissue cells under direct microscopic visualization.

Fluorescence-based analysis of cellular protein lysate arrays using quantum dots.

Reverse-phase protein microarrays (RPPMAs) enable heterogeneous mixtures of proteins from cellular extracts to be directly spotted onto a substrate (such as a protein biochip) in minute volumes (nanoliter-to-picoliter volumes). The protein spots can then be probed with primary antibodies to detect important posttranslational modifications such as phosphorylations that are important for protein activation and the regulation of cellular signaling. Previously, we relied on chromogenic signals for detection.

Physicochemically modified silicon as a substrate for protein microarrays.

Reverse phase protein microarrays (RPMA) enable high throughput screening of posttranslational modifications of important signaling proteins within diseased cells. One limitation of protein-based molecular profiling is the lack of a PCR-like intrinsic amplification system for proteins. Enhancement of protein microarray sensitivities is an important goal, especially because many molecular targets within patient tissues are of low abundance.

Multispectral imaging of clinically relevant cellular targets in tonsil and lymphoid tissue using semiconductor quantum dots.

Determination of the expression and spatial distribution of molecular epitopes, or antigens, in patient tissue specimens has substantially improved the pathologist's ability to classify disease processes. Certain disease pathophysiologies are marked by characteristic increased or decreased expression of developmentally controlled antigens, defined as Cluster of Differentiation markers, that currently form the foundation for understanding lymphoid malignancies. While chromogens and organic fluorophores have been utilitized for some time in immunohistochemical analyses, developments in synthetic, inorganic fluorophore semiconductors, namely quantum dots, offer a versatile alternative reporter system.

Accurate diagnosis of acute graft-versus-host disease using serum proteomic pattern analysis.

Objective: The rapid diagnosis of acute graft-versus-host disease (GVHD) following allogeneic hematopoietic cell transplantation (HCT) is important for optimizing the management of this life-threatening complication. Current diagnostic techniques are time-consuming and require invasive tissue sampling. We investigated serum protein pattern analysis using surface-enhanced laser desorption ionization time-of-flight (SELDI-TOF) mass spectrometry as a tool to diagnose GVHD.

Fractionation of serum components using nanoporous substrates.

Numerous previously uncharacterized molecules resident within the low molecular weight circulatory proteome may provide a picture of the ongoing pathophysiology of an organism. Recently, proteomic signatures composed of low molecular weight molecules have been identified using mass spectrometry combined with bioinformatic algorithms. Attempts to sequence and identify the molecules that underpin the fingerprints are currently underway.

Intestinal disease in Hermansky-Pudlak syndrome: occurrence of colitis and relation to genotype.

Background & Aims: Hermansky-Pudlak syndrome (HPS), a rare autosomal recessive disorder characterized by oculocutaneous albinism and platelet dysfunction, results from mutations in 1 of at least 7 different genes. Some patients develop a fatal pulmonary fibrosis and others a disabling colitis. This study aimed to document the occurrence of colitis among HPS patients, characterize gastrointestinal tract involvement in HPS, and analyze the distribution of colitis among HPS genotypes.

The amplified peptidome: the new treasure chest of candidate biomarkers.

Mass spectrometric analysis of the low-molecular weight (LMW) range of the serum/plasma proteome is revealing the existence of large numbers of previously unknown peptides and protein fragments predicted to be derived from low-abundance proteins. This raises the question of why such low abundance molecules would be retained at detectable levels in the circulation, instead of being rapidly cleared and excreted. Theoretical models of biomarker production and association with serum carrier proteins have been developed to elucidate the mechanisms governing biomarker half-life in the bloodstream.

Nanoparticles: potential biomarker harvesters.

A previously untapped bank of information resides within the low molecular weight proteomic fraction of blood. Intensive efforts are underway to harness this information so that it can be used for early diagnosis of diseases such as cancer. The physicochemical malleability and high surface areas of nanoparticle surfaces make them ideal candidates for developing biomarker harvesting platforms.

Pegylated, steptavidin-conjugated quantum dots are effective detection elements for reverse-phase protein microarrays.

Protein microarray technologies provide a means of investigating the proteomic content of clinical biopsy specimens in order to determine the relative activity of key nodes within cellular signaling pathways. A particular kind of protein microarray, the reverse-phase microarray, is being evaluated in clinical trials because of its potential to utilize limited amounts of cellular material obtained through biopsy. Using this approach, cellular lysates are arrayed in dilution curves on nitrocellulose substrates for subsequent probing with antibodies.

Physiological mechanisms of tumor-cell invasion and migration.

Recent advances in understanding the complex biology of the microenvironment that underlies tumor invasion and migration have revealed novel and promising therapeutic targets. Pharmacological blockade of intra- and extracellular signaling events that regulate migration and survival of multiple cell types may disrupt the host-tumor conspiracy that allows escape from normal developmental regulation.

Pathology of the future: molecular profiling for targeted therapy.

Recent evidence suggests that each patient's cancer has a unique subset of molecular pathogenetic derangements. These derangements may both genetic and proteomic alterations. Genomic and proteomic research tools enable genome-wide assessment of gene expression as well as kinase driven cell signaling events.

Protein pathway analysis in Clinical Proteomics using protein microarrays.

Molecular diagnostics research within the field of cancer is increasingly focused on detecting low-abundance protein endpoints that can be used to define a patient's disease more completely. Protein microarrays represent an important Clinical Proteomics tool for directly measuring protein endpoints in samples extracted from patient tissues. By combining laser capture microdissection, arraying devices, validated isoform-specific antibodies and advanced reporter technology tools, Clinical Proteomics laboratories are currently generating molecular portraits of cancer cells harvested from patient biopsies.

Opportunities for nanotechnology-based innovation in tissue proteomics.

Within this review we discuss two methodologies used in tissue proteomics, namely mass-spectrometry (MS)-based protein pattern diagnostics and protein microarrays. Further, we describe current goals within the field of tissue proteomics and suggest points of departure for designing nanotechnology-based tools that will enhance the role of molecularly based diagnostics and therapeutics development in clinical medicine.

Serum proteomics in cancer diagnosis and management.

Mass spectrometry-based diagnostics has the potential to revolutionize molecular medicine. Using modern mass-spectrometer technologies, clinical tests can be developed that are practical, robust, accurate, and inexpensive. Serum proteomic pattern profiling couples mass spectrometry with adaptive artificial-intelligence-based bioinformatics, which can now be employed to detect pathological states reflected in the serum proteome.