The purpose of this study was to determine whether the residual fixative from a liquid-based Pap test or a swab of the cervix contained proteins that were also found in the primary tumor of a woman with high grade serous ovarian cancer. This study is the first step in determining the feasibility of using the liquid-based Pap test or a cervical swab for the detection of ovarian cancer protein biomarkers. Proteins were concentrated by acetone precipitation from the cell-free supernatant of the liquid-based Pap test fixative or eluted from the cervical swab. Protein was also extracted from the patient’s tumor tissue. The protein samples were digested into peptides with trypsin, then the peptides were run on 2D-liquid chromatography mass spectrometry (2D-LCMS). The data was searched against a human protein database for the identification of peptides and proteins in each biospecimen. The proteins that were identified were classified for cellular localization and molecular function by bioinformatics integration. We identified almost 5000 proteins total in the three matched biospecimens. More than 2000 proteins were expressed in each of the three biospecimens, including several known ovarian cancer biomarkers such as CA125, HE4, and mesothelin. By Scaffold analysis of the protein Gene Ontology categories and functional analysis using PANTHER, the proteins were classified by cellular localization and molecular function, demonstrating that the Pap test fluid and cervical swab proteins are similar to each other, and also to the tumor extract. Our results suggest that Pap test fixatives and cervical swabs are a rich source of tumor-specific biomarkers for ovarian cancer, which could be developed as a test for ovarian cancer detection.

中文翻译：

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基于质谱的蛋白质组学评估Pap试验液和宫颈拭子作为临床诊断生物标本检测卵巢癌的潜力

这项研究的目的是确定基于液体的巴氏试验或子宫颈拭子中残留的固定剂是否含有在患有高度浆液性卵巢癌的女性原发性肿瘤中也发现的蛋白质。这项研究是确定使用基于液体的Pap检测或宫颈拭子检测卵巢癌蛋白生物标志物可行性的第一步。通过丙酮从液态的Pap测试固定液的无细胞上清液中浓缩蛋白质，或从宫颈拭子上洗脱蛋白质。还从患者的肿瘤组织中提取蛋白质。用胰蛋白酶将蛋白质样品消化成肽，然后在2D-液相色谱质谱法（2D-LCMS）上运行这些肽。针对人类蛋白质数据库搜索数据，以鉴定每种生物样本中的肽和蛋白质。通过生物信息学整合对鉴定出的蛋白质进行细胞定位和分子功能分类。我们在三个匹配的生物样本中共鉴定出近5000种蛋白质。在三个生物样本中的每个样本中表达了2000多种蛋白质，包括几种已知的卵巢癌生物标记物，例如CA125，HE4和间皮素。通过对蛋白质基因本体论类别的支架分析和使用PANTHER的功能分析，通过细胞定位和分子功能对蛋白质进行了分类，证明Pap测试液和宫颈拭子蛋白质彼此相似，并且与肿瘤提取物相似。