SBIR-STTR Award

This Small Business Innovation Research Phase I project aims to develop a technology that employs polyclonal antibodies as a complex probe to discover tumor associated surface antigens, a process named Dual Immunostaining-mediated Subtractive Cloning (DISC). Antibodies have been the most powerful tools to dissect the expression and structure of proteins. Immune system has evolved to respond to foreign antigens by generating antibodies recognizing most, if not all, foreign epitopes. It is thus a powerful tool to search for structural and quantitative differences on cell surface proteins between a normal cell and a diseased cell. Disease-associated cell surface antigens are ideal markers for diagnostics and potential targets for therapeutic intervention. To discover novel disease-related cell surface molecules, we propose a novel technology that combines three proven techniques: whole cell immunization, flow cytometry and cDNA expression cloning, to identify surface antigens that quantitatively or structurally unique to diseased cells such as cancer cells. These tumor-associated antigens identified in this process will be used to generate monoclonal antibody microarrays for the detection and staging of cancer in Phase II of the project. DISC technology that Epitomics is attempting to develop in Phase I will lead to discovery of novel tumor associated antigens in a panel of human cancers (Phase II project). Rabbit monoclonal antibodies against these antigens will be produced from the cell lines generated in DISC process. Epitomics intends to develop and commercialize antibody microarrays for cancer detection and staging, using monoclonal antibodies for the existing and newly discovered tumor antigens

The discovery and identification of novel tumor associated antigens (TAAs) is critical for the advancement of accurate cancer diagnosis and staging. This Small Business Innovation Research Phase II project aims to continue development and application of a novel technology, Dual Immunostaining mediated Subtractive Cloning (DISC). The technology allows molecular cloning of genes that encode tumor cell surface proteins that are structurally or quantitatively different from those in normal cells. In Phase I, the feasibility of DISC was demonstrated. We have shown that rabbit polyclonal antibodies can be used as a complex probe to discover tumor associated cell surface antigens. Using the tumor cell line HeLa S3 and primary normal human fibroblast cells, polyclonal antibodies against these cell types were purified and effectively labeled using fluorescent dyes. A highly efficient method was established to identify cell surface antigens or unique epitopes, only expressed in tumor cells. In Phase II, DISC will be further developed and used to clone TAAs for human cancers of the breast, the prostate, and the lung. Tumor cell lines, tumor tissues, corresponding normal primary cells and normal tissues will be used to clone TAA genes. In the same process, rabbit cell lines expressing these TAAs will be obtained. Rabbit monoclonal antibodies against these TAAs will be generated from these TAA expressing cell lines. Tumor specificity of the newly discovered TAAs and commercial potential of the rabbit monoclonal antibodies will be evaluated by tumor tissue arrays.

Benefits:
In this SBIR Phase II, Epitomics will discover and develop new TAAs and rabbit monoclonal antibodies that will enable: 1) the rapid identification and characterization of novel tumor antigen targets, and 2) commercial development of diagnostic kits. Epitomics will supply the TAA genes and rabbit monoclonal antibodies to cancer researchers for clinical studies, commercialize them as research reagents and further develop some of the rabbit monoclonal antibodies into products for cancer staging and diagnosis.

Keywords:
cancer detection, tumor associated antigen, rabbit monoclonal antibody, high throughput, tissue array, breast cancer, prostate cancer, lung cancer