Plasma proteomic analysis of patients with squamous cell carcinoma of the uterine cervix.

OBJECTIVE To compare plasma protein expression between patients with squamous cell carcinoma (SCC) of the cervix and normal controls. METHODS Plasma samples from patients with benign gynecological disease (normal cervix, n=6) and cervical cancer (SCC, n=6) were subjected to plasma proteomic analysis using two dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization mass spectroscopy (MALDI-MS). Western blotting and immunoturbidimetric assay were performed to validate the results of 2-DE. RESULTS Eight proteins showed differential expression between controls and SCC patients; six (ceruloplasmin, complement C3, afamin precursor, alpha-1-B-glycoprotein, transferrin, alpha-fibrinogen precursor) were up-regulated, while two (chain A, crystal structure of antithrombin and apolipoprotein A-IV precursor) were down-regulated in the plasma of SCC patients. Western blotting analysis revealed significant elevation of ceruloplasmin, complement C3, afamin, and alpha-1-B-glycoprotein in the plasma of SCC patients in comparison to controls. Immunoturbidimetric assay of a larger group confirmed the results of 2-DE and Western blotting, and showed that ceruloplasmin and complement C3 were significantly elevated in the plasma of SCC patients in comparison with controls and patients with carcinoma in situ (CIS) of the uterine cervix. CONCLUSION Plasma protein expression determined using 2-DE and MALDI-MS will give a chance to identify tumor-specific biomarkers for SCC of the cervix.