Detection of Serum Lysophosphatidic Acids Using Affinity Binding and Surface Enhanced Laser Desorption/Ionization (SELDI) Time of Flight Mass Spectrometry

Abstract

Put ic reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Washington Headquarters Services, Directorate ABSTRACT (Maximum 200 Words)We proposed to apply two novel technologies to the development of an approach suitable for screening for ovarian cancer in high and low risk women. The first of these is a novel approach to the development of antibodies which will recognize specific phospholipids and lysophospholipids present in ovarian cancer patients and the second of these is SELDI tof mass spectroscopy. These two technologies will be merged with powerful computing tools to develop approaches capable of detecting ovarian cancer at an early, curable stage. This approach will further benefit from the expertise of the Mills laboratory (LPA screening, SELDI tof) with that of the Prestwich laboratory (lipid synthesis and antibody development). Progress We have demonstrated that SELDI mass spectroscopy has the ability to detect model lysophospholipids present in plasma and serum. The sensitivity of the assay using standard capture chips is low and would require relatively large volumes of sera to detect the different lysophospholipid isoforms. This will require prepurification approaches to concentrate the lipids which we have now developed. We have obtained a pan sphingosine 1 phosphate antibody as a capture reagent. This antibody is able to bind all isoforms of S I P and when combined with SELDI should allow detection of isoforms of this lysophospholipid. We have shown that the antibodie can detect Si P levels in complex ascites mixtures. We are currently evaluating different CHIP forms for SELDI and developing LPA antibodies as well as obtaining LPA binding proteins to increase the ability to capture lysophospholipids through collaborative approaches.