Identification of candidate biomarkers in ovarian cancer serum by depletion of highly abundant proteins and differential in-gel electrophoresis.
Ovarian cancer is the fifth leading cause of cancer death for women in the US, yet survival rates are over 90% when it is diagnosed at an early stage, highlighting the need for biomarkers for early detection. To enhance the discovery of tumor-specific proteins that could represent novel serum biomarkers for ovarian cancer, we depleted serum of highly abundant proteins which can mask the detection of proteins present in serum at low concentrations. Three commercial immunoaffinity columns were used in parallel to deplete the highly abundant proteins in serum from 60 patients with serous ovarian carcinoma and 60 non-cancer controls. Medium and low abundance serum proteins from each serum pool were then evaluated by the quantitative proteomic technique of differential in-gel electrophoresis. The number of protein spots that were elevated in ovarian cancer sera by at least twofold ranged from 36 to 248, depending upon the depletion and separation methods. From the 33 spots picked for MS analysis, nine different proteins were identified, including the novel candidate ovarian cancer biomarkers leucine-rich alpha2 glycoprotein-1 and ficolin 3. Western blotting validated the relative increases in serum protein levels for three of the proteins identified, demonstrating the utility of this approach for the identification of novel serum biomarkers for ovarian cancer.
Andersen
John D
JD
Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA.
Boylan
Kristin L M
KL
Xue
Feifei S
FS
Anderson
Lorraine B
LB
Witthuhn
Bruce A
BA
Markowski
Todd W
TW
Higgins
Leeann
L
Skubitz
Amy P N
AP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000737:chemistry* / Q000302:isolation & purification; D001798:Blood Proteins / Q000737:chemistry* / Q000302:isolation & purification; D015153:Blotting, Western; D016022:Case-Control Studies; D002851:Chromatography, High Pressure Liquid; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods*; D005260:Female; D006801:Humans; D007136:Immunoglobulins; D007163:Immunosorbent Techniques; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000097:blood*; D015203:Reproducibility of Results
D014408:Biomarkers, Tumor; D001798:Blood Proteins; C016512:IgY; D007136:Immunoglobulins