Division of Gynecologic Oncology, Department of Obstetrics, Gynecology, and Reproductive Sciences at Magee-Womens Hospital of the University of Pittsburgh School of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America.
PLoS One. 2011;6(9):e25056. doi: 10.1371/journal.pone.0025056. Epub 2011 Sep 30.
Epithelial ovarian cancer (EOC) is the deadliest gynecologic malignancy in the United States. Unfortunately, a validated protein biomarker-screening test to detect early stage disease from peripheral blood has not yet been developed. The present investigation assesses the ability to identify tumor relevant proteins from ovarian cancer proximal fluids, including tissue interstitial fluid (TIF) and corresponding ascites, from patients with papillary serous EOC and translates these findings to targeted blood-based immunoassays.
METHODOLOGY/PRINCIPAL FINDINGS: Paired TIF and ascites collected from four papillary serous EOC patients at the time of surgery underwent immunodepletion, resolution by 1D gel electrophoresis and in-gel digestion for analysis by liquid chromatography-tandem mass spectrometry, which resulted in an aggregate identification of 569 and 171 proteins from TIF and ascites, respectively. Of these, peroxiredoxin I (PRDX1) was selected for validation in serum by ELISA and demonstrated to be present and significantly elevated (p = 0.0188) in 20 EOC patients with a mean level of 26.0 ng/mL (±9.27 SEM) as compared to 4.19 ng/mL (±2.58 SEM) from 16 patients with normal/benign ovarian pathology.
CONCLUSIONS/SIGNIFICANCE: We have utilized a workflow for harvesting EOC-relevant proximal biofluids, including TIF and ascites, for proteomic analysis. Among the differentially abundant proteins identified from these proximal fluids, PRDX1 was demonstrated to be present in serum and shown by ELISA to be elevated by nearly 6-fold in papillary serous EOC patients relative to normal/benign patients. Our findings demonstrate the facile ability to discover potential EOC-relevant proteins in proximal fluids and confirm their presence in peripheral blood serum. In addition, our finding of elevated levels of PRDX1 in the serum of EOC patients versus normal/benign patients warrants further evaluation as a tumor specific biomarker for EOC.
上皮性卵巢癌（EOC）是美国最致命的妇科恶性肿瘤。不幸的是，尚未开发出一种经过验证的蛋白质生物标志物筛选测试，以从外周血中检测早期疾病。本研究评估了从患有乳头状浆液性 EOC 的患者的卵巢癌近端液（包括组织间质液（TIF）和相应的腹水）中识别肿瘤相关蛋白的能力，并将这些发现转化为靶向基于血液的免疫测定。
方法/主要发现：在手术时从四名患有乳头状浆液性 EOC 的患者收集配对的 TIF 和腹水，进行免疫耗尽，通过 1D 凝胶电泳解析，然后进行胶内消化，用于液相色谱-串联质谱分析，结果分别从 TIF 和腹水鉴定出 569 种和 171 种蛋白质。其中，过氧化物还原酶 I（PRDX1）被选为 ELISA 验证血清中的验证物，并证明在 20 名 EOC 患者中存在且显著升高（p=0.0188），平均水平为 26.0ng/ml（±9.27SEM），而 16 名正常/良性卵巢病理患者的水平为 4.19ng/ml（±2.58SEM）。
结论/意义：我们已经利用了一种从包括 TIF 和腹水在内的 EOC 相关近端生物液中收获蛋白质组分析相关的生物流体的工作流程。在这些近端流体中鉴定出的差异丰富的蛋白质中，PRDX1 被证明存在于血清中，并通过 ELISA 证明在乳头状浆液性 EOC 患者中相对于正常/良性患者升高近 6 倍。我们的发现证明了在近端流体中发现潜在的 EOC 相关蛋白并确认其在周围血液血清中的存在的简便能力。此外，我们发现 EOC 患者血清中 PRDX1 水平升高，相对于正常/良性患者，值得进一步评估作为 EOC 的肿瘤特异性生物标志物。
