Alterations in the serum proteome profile during the development of ovarian cancer

Ovarian cancer causes more deaths than any other malignant tumor of the female reproductive system. This is because the condition usually goes undetected until the late stages. The purpose of the present study is to identify alterations in the serum proteome profile during the development of ovarian cancer and to provide an experimental basis for discovering new and valuable serum biomarkers for the early detection of ovarian carcinoma. Surface-enhanced laser desorption/ionization-time of flight (SELDI-TOF-MS) was used to profile changes in the serum proteome of Fischer 344 rats with ovarian cancer during the progress of tumor development. Sera were collected from the rats on day A (1 week before injection of tumor cells), day B (4 weeks after injection), and day C (6 weeks after injection). Each sample was subjected to SELDI-TOF-MS testing. Peak detection and alignment and selection of peaks with the highest discriminatory power were performed using proteinchip biomarker software. Decision tree analyses were performed using biomarker pattern software. Finally, 3 peaks were found to be the most valuable ones (3759, 4659 and 9318 Da). The expression frequency of m/z 3759-Da peaks was downregulated and another two frequencies (4659 and 9318 Da) were upregulated, and the levels of expression of these three proteins showed the same tendency as the expression frequency during the development of ovarian cancer. The total accuracy rate of diagnosis at 4 and 6 weeks post-injection was 94.7 and 97.3%, respectively. Profiling the serum proteome changes during the process of the cancer development using SELDI-TOF-MS may provide useful information regarding carcinogenesis and facilitate discovery of novel serum biomarkers for early detection.