LIPID MICROARRAYS

Phosphoinositides (PIP/nS), phospholipids (PLs), and sphingolipids (SLs) recruit signaling proteins and effectors to initiate signal transduction in response to internal and external signals.. Cellular processes such as endocytosis, protein sorting, cell proliferation, apoptosis, and cytoskeletal remodeling are regulated by temporal and spatial changes in lipids. Currently, there are no approved tests that quantify membrane lipid profiles for cancer diagnosis or outcome prognosis. Profiling of lipids and their binding proteins can elucidate signaling pathways and suggest molecular markers for diagnosis. The techniques of cDNA microarrays in genomics and protein arrays for proteomics have recently inspired the development of microarrays of small molecules (e.g., natural products, drug candidates, peptide). We will establish the feasibility of using immobilized lipids to develop analytical "lipidomics." The proposed "lipid chip" will be used to evaluate patterns of lipid binding proteins and patterns of total cellular lipids. Four standard PIP/n molecules and two PLs will be immobilized on chemically-modified glass slides. With this patterned lipid chip, two different assays will be developed for measuring selectivity and affinity of PIPn-binding proteins and for quantifying PIP/nS. The technology optimized in Phase I will be used to develop a complete lipid array system for cancer-relevant lipids. PROPOSED COMMERCIAL APPLICATIONS: Lipid microarrays that allow quantification of phospholipids and binding proteins have value in academic, health care, and pharmaceutical drug development settings. Systemic screening of cell extracts and pathology samples will allow rapid and early detection lipid imbalances in cancer.