Proteomic Analysis of Ovarian Cancer Tissue and Proximal Fluid for Biomarker Discovery

Description of projects available to graduate students:
Ovarian cancer is insidious in presentation with no sentinel symptoms such as vaginal bleed to allow early detection. Early stage disease is highly curable but usually completely asymptomatic. Previous attempts at developing assays have attempted to use proteomic profiling of serum or plasma on cohorts collected from patients. Identification of novel biomarkers from serum and plasma is extremely challenging due to the very high dynamic range of concentration (greater than 10^10) between the 22 most abundant proteins and the expected thousands of low abundant proteins. This very high background matrix presented by the most abundant proteins serves to prevent facile identification of what are likely to be small changes in abundance among the low abundance proteins reflective of an early stage malignancy. Most of the clinical signs and symptoms of ovarian cancer have either direct or indirect association with the propensity for fluid production from neoplasms. This fluid is not readily assessable without surgery or percutaneous aspiration, but is likely to be markedly enriched for potential screening biomarkers when compared to the concentration and background variability seen in the serum, as described. This concentration gradient has been previously demonstrated for CA 125 where it was found that this protein and other tumor antigens were thousands-fold greater in proximity to the developing malignancy when compared to their concentration in serum. We have devised a loco-regional sampling strategy of tissue interstitial fluid (TIF) that samples active tissue for collection of shed and secreted proteins produced in the tissue microenvironment that we propose to utilize in a proteomic discovery effort to identify novel protein biomarkers of early stage ovarian cancer. Mass spectrometry will be used to differentially profile the proteomes from the loco-regional fluids toward identification of putative biomarkers at curable stages of disease. Novel proteins identified from the TIF that are demonstrated to be associated with early stage ovarian cancer will then be evaluated for their presence in serum/plasma and the extent to which they correlate with early stage disease.

Techniques graduate student will learn:
tissue culture
mass spectrometry
protein chemistry
analytical chemistry
bioinformatics