Journal of Proteomics & Bioinformatics
Open Access

Abstract

Proteomic Analysis of Ovarian Cancer Tumor Fluid is a Rich Source of Potential Biomarkers

Aline Poersch, Lucas Oliveira Sousa, Lewis Joel Greene, Vitor Marcel Faça, and Francisco Jose Candido dos Reis

Proteomic analysis of body fluids can be used to identify proteins associated with malignant transformation. We investigated the potential of hightroughput proteomics to profile the proteins in ovarian cancer tumor fluid. Tumor fluid samples were obtained from 10 women with high-grade ovarian serous carcinoma and from 10 women with benign serous cystadenoma. The samples were subjected to immunodepletion of albumin and IgG, followed by in-depth proteomic profiling by LC-MS/MS. A total of 1135 proteins were identified, 358 (32%) were detected in both malignant and benign pools, 505 (44%) only in the malignant pool, and 272 (24%) only in the benign pool. The proteomic profile of tumor fluid was similar to human plasma and the secretome of ovarian cancer cells. Proteins related to cellular metabolism were predominantly present in tumor samples. TIMP1 was determined by ELISA, confirming the proteomic data and its significantly higher level in individual malignant tumor fluids when compared with benign tumor fluids. In the present study, proteomic analysis of tumor fluid permited the identification of a large number of proteins expressed only in malignant tumors. Proteomic analysis of tumor fluid is a strategy in studies of biomarkers for ovarian cancer that can lead to significant advancements in the diagnosis and treatment of the disease.