Proteomic profiling of peritoneal rinse fluid sediment separates patients with ovarian cancer from women admitted for cesarean section. A pilot study

Abstract

Objective. There is a great need for additional approaches to discover putative biomarkers for ovarian cancer that accounts for 5% of all cancer deaths among women and is the leading cause of deaths among gynecologic malignancies in the United States. Methods. Peritoneal rinse fluid sediment from seven patients having ovarian cancer and four women admitted for cesarean section was analysed by proteomic techniques using two-dimensional gel electrophoresis and tandem mass spectrometry. Results. Sixteen protein spots were found to be significantly and highly up-regulated in samples from cancer patients as compared with the cesarean section group. Nine of the protein spots were identified as C-terminal fragments of fibrinogen-β (spot Nos. 5404 and 5408), haptoglobin-α2 (spot Nos. 4101 and 6103), haptoglobin-β (spot Nos. 2502, 2504, 3502 and 4401) and transthyretin (spot No. 4002). Generally, several isoelectric variants were present of each protein. The protein concentration in the sediment of spot No. 506 and spot No. 5404 (identified as fibrinogen-β) was significantly (p < 0.05) and negatively correlated with survival rate of the ovarian cancer patients while for three of the spots a borderline significant (p < 0.07) negative correlation was found. Conclusions. It is suggested that further development of this method may give a basis for identifying suitable diagnostic and prognostic biomarkers for ovarian cancer.