Numerous small businesses design and develop proteomic technologies for the accurate and powerful measurement of proteins and other biomolecules related to disease. Without high quality, well-characterized standard reagents, however, it is impossible to translate such platforms into products and services that could be used effectively by the cancer community.
To maximize the initiative's capabilities and impact, CPTC is partnering with the biotechnology industry via the NCI's Small Business Innovation Research (SBIR) Program, a contract mechanism that supports early stage research and development by small businesses. Through the SBIR program, CPTC aims to integrate its efforts with those of the biotechnology industry by encouraging and enabling companies developing proteomic technologies and platforms to adopt standardized, well-characterized reagents – including high quality proteins and validated capture reagents (e.g., antibodies) – in the commercialization of new tools and kits for the cancer community.
"High-throughput Selection of Aptamers against Cancer Biomarkers"
"Yeast Single Chain Antibodies as Capture Reagents"
The objective if this is to develop and validate novel systems for efficient expression of cancer-related human glycosylated proteins. The availability of such systems will aid analysis of cancer related proteins, especially those of low abundance from bodily fluids, and accelerate the development of effective cancer diagnostics and therapeutics.
The baculovirus expression vector systems (BEVS) using insect cells provide an alternative at lower cost and faster turnaround time to mammalian systems. The company will develop a complete system to utilize BEVS in both insect and mammalian cells with unique purification methods and flexibility to produce glycosylated proteins.
Aptakon has developed a 10 kD protein scaffold with loops similar to the complementarity determining region of the immunoglobulin domain. Aptakon seeks to demonstrate the feasibility of identifying alternative affinity capture reagents for soluble proteins by screening phage and bacterial display libraries of its novel scaffold. This platform will be applied to the development of affinity capture reagents against 10 clinically relevant cancer biomarkers, for which antibodies are commercially available in order to demonstrate the affinity capture reagents' utility, reliability, and value.
"Recombinant Antibodies as Affinity Captures"
AvantGen has constructed a yeast display antibody library with rationally designed complementarity determining regions (CDRs) containing large number of productive and functional antibodies capable of binding various antigens with high affinity and specificity. The goal of this proposed research is to isolate recombinant antibodies for selected cancer biomarkers with high specificity and affinity using AvantGen's technology platform. In phase I study, antibodies to 10 cancer biomarkers will be isolated. The affinity and specificity of these antibodies will be determined by ELISA-based assays, Western blot and Biacore. It is expected that these antibodies will be able to effectively compete with monoclonal antibodies in terms of protein recognition, binding affinity, and detection and can be reproducibly produced in a cost-effective and efficient manner.
This project utilizes a new tool, "massively parallel selection of DNA aptamers" to rapidly identify high-affinity ligands to hundreds or even thousands of protein targets simultaneously. Aptamers represent at extremely promising class of ligands for therapeutics, diagnostics, and other applications. In phase I study, BioTex will demonstrate the utility of their tool for selecting aptamers to 100 important cancer biomarkers and characterize many of them by accepted practices.
"Mapping of Epitopes on Cancer Biomarkers"The objective of this contact in phase I research is to develop and validate multiplex mass spectrometric immunoassays (MSIA) for detection and quantification of cancer-related proteins with intrinsically low bodily fluids concentrations. In the first specific aim, the company will develop, optimize, test, and validate a MSIA assay for cancer-related protein whose intrinsic concentration in a bodily fluid (i.e., plasma) is in the 1-10 ng/mL range. A quantitative MSIA assay utilizing a standard curve approach will be developed, and the limits of detection and quantifications will be determined. The assay will be tested with at least a dozen different human plasma samples, in triplicate, and the CVs of the assay will be determined. Usability testing of the assay will be performed with three representative users, and their feedback will be used to make modifications and improvements. The results obtained with the MSIA assay will be compared to a commercially available ELISA assay. In the second specific aim, the company will create a multiplexed MSIA assay that will be able to detect and profile five plasma proteins simultaneously, with a concentration range of 1 ng/mL - 1 mg/mL. Various ratios of antibodies will be immobilized in the affinity pipettes and the assay will be tested on a standard solution of antigens in their physiological concentration to determine the best ratio of antibodies that produces comparable signals in the mass spectra for all proteins, without signal suppression issues. The limit of detection and CVs of the multiplex assay will be determined.
The overall objective of the phase II research is to develop a fully functional quantitative, automated, high-throughput, multiplex affinity protein capture technology platform and Multiplex Mass Spectrometric Immunoassays for analysis of low abundance cancer related proteins/peptides from bodily fluids. The company will start by identifying potential protein and peptide targets and their corresponding affinity reagents. Depending on the availability of such reagents, they will compile a list of more than 50 cancer-related proteins and peptides, and initiate development of individual Mass Spectrometric Immunoasays for each target. The performance of the individual assays will be assessed in regards to their sensitivity and reproducibility Those targets for which the assays pass the performance criteria will be evaluated for grouping into 10 sets of Multiplex Mass Spectrometric Immunoassays, each targeting 5 protein/peptide analytes. The multiplex assays will also include an internal reference for quantification purposes. The multiplex assays, which represent the final product of this research, will be evaluated and validated in regards to their limits of detection, reproducibility, sensitivity, and specificity. As a final task of the project the company will assemble kits containing the multiplex assays, reagents, and protocols, and evaluate other product-related variables such as packaging and storage conditions.
"Novel Protein Expression Technologies for Glycoproteins"Protein phosphorylation is a central mechanism of cellular regulation. Aberrant phosphorylation activities can cause human cancers. Highly specific capturing reagents are needed to detect and monitor these activities with the aim of detecting cancer early. To generate, characterize and validate these capturing reagents, sufficient amounts of functional phosphoproteins are needed. The long-term goal of this project is to establish a cell-free protein synthesis system that can be used to produce large quantities of site-specifically phosphorylated proteins. The system will feature low cost, high reproducibility, high quality and high yield. The key advancement of the new method is made possible by incorporating phosphoamino acids through site-directed nonsense suppression. Specific reagents will be developed to activate phosphoamino acids efficiently and continuously in the translation reaction. Translation termination at the selected nonsense codon will be manipulated to achieve high suppression efficiency. This cell-free protein sysnthesis system will comprise of both prokaryotic and eukaryotic translation systems. In phase I, the objective is to develop an E.coli cell-free system that is able to produce proteins containing phosphotyrosines in a yield up 0.5 mg per 1 ml of translation reaction.
"An Expression System for Synthesis of Glycoprotein with Defined O-Glycan Structure"
The company proposed a novel approach to protein detection and quantification in bodily fluids that integrates three technologies with which Sequenom, Inc. and their collaborators have expertise in: immuno-PCR, competitive-PCR, and mass spectrometric analysis using Sequenom's MassARRAY platform.