Biologically and clinically relevant proteomics data can only be generated if organ or tissue samples investigated consist of homogeneous cell populations, in which no unwanted cells of different types and/or development stages obscure the results. Thus, several tissue microdissection technologies have been developed to provide a rapid and straightforward method for procuring homogeneous subpopulations of cells for biochemical and molecular biological analyses. However, current proteomic techniques, including 2-D PAGE, multidimensional liquid chromatography systems, and gel and gel-free isoelectric focusing approaches such as chromatofocusing, immobilized pH membranes, Rotofor, and free-flow electrophoresis, are all operated at the preparative-scale and are incompatible with small cell populations collected from microdissection-procured specimens. Thus, the reported tissue proteomics studies are mainly based on the analysis of entire tissue sections instead of targeted cell subpopulations. Clearly, development of the capability to enable tissue-based clinical proteomic studies will have far reaching impacts on protein biomarker investigations of disease through interrogation of the archived tissue collections. Our research goal is therefore to combine the novel tissue sample preparation and proteomic technologies that enable comprehensive and comparative survey of protein expression profiles in targeted tumor cell populations isolated from human tissues. By combining Calibrant's unique ability to perform proteomic profiling from minute samples with the expertise offered by Dr. Wenxin Zheng at the University of Arizona Medical College in cancer pathology, gynecology, and tissue microdissection, the proposed research represents a synergistic effort toward the evaluation and validation of a novel biomarker discovery paradigm for enabling the proteomic analysis of cancer cells and their micro-environment in support of cancer research, diagnosis, and treatment. Application of the resulting biomarker discovery platform for studying the molecular mechanisms associated with ovarian carcinoma will be realized also through the collaboration with Dr. Zheng, a gynecologic pathologist, to provide access to a collection of primary ovarian epithelial tumor specimens.
Comprehensive and comparative proteomics studies of microdissected ovarian epithelial tumor specimens are proposed in this STTR Phase I project and are expected to provide significant details at the global level on the molecular mechanisms associated with ovarian epithelial carcinogenesis. Identification of differentially expressed proteins that are characteristic of a clearly defined disease state paves the way for defining the molecular and biochemical pathways by which normal cells progress to cancerous states in addition to nurturing discovery of biological markers and therapeutic targets for ovarian cancer. The greatest expectations for targeted proteomics research using enriched non-malignant or malignant ovarian cells from high quality tissue specimens reside in the identification of diagnostic, prognostic, and predictive biological markers in the clinical setting, as well as the discovery and validation of new protein targets in the biopharmaceutical industry.
