Plasma Protein Biomarkers Associated with Higher Ovarian Cancer Risk in BRCA1/2 Carriers

Abstract

Ovarian cancer (OC) is the most lethal gynecologic malignancy and in-time diagnosis is limited because of the absence of effective biomarkers. Germline BRCA1/2 genetic alterations are risk factors for hereditary OC; risk-reducing salpingo-oophorectomy (RRSO) is pursued for disease prevention. However, not all healthy carriers develop the disease. Therefore, identifying predictive markers in the BRCA1/2 carrier population could help improve the identification of candidates for preventive RRSO. In this study, plasma samples from 20 OC patients (10 patients with BRCA1/2 wild type (wt) and 10 with the BRCA1/2 variant (var)) and 20 normal subjects (10 subjects with BRCA1/2wt and 10 with BRCA1/2var) were analyzed for potential biomarkers of hereditary OC. We applied a bottom-up proteomics approach, using nano-flow LC-MS to analyze depleted plasma proteome quantitatively, and potential plasma protein markers specific to the BRCA1/2 variant were identified from a comparative statistical analysis of the four groups. We obtained 1505 protein candidates from the 40 subjects, and SPARC and THBS1 were verified by enzyme-linked immunosorbent assay. Plasma SPARC and THBS1 concentrations in healthy BRCA1/2 carriers were found to be lower than in OC patients with BRCA1/2var. If plasma SPARC concentrations increase over 337.35 ng/ml or plasma THBS1 concentrations increase over 65.28 mg/ml in a healthy BRCA1/2 carrier, oophorectomy may be suggested.

Novel Diagnostic Biomarkers for High-Grade Serous Ovarian Cancer Uncovered by Data-Independent Acquisition Mass Spectrometry

“…Our targeted MS assays showed that expressions of 18 out of 21 candidates showed statistically significant (P < 0.05) changes between HGSOC and HCs (Table 2), consistent with those from LC−DIA− MS/MS analysis. Some of the 18 biomarker candidates have previously been suggested as potential serum diagnostic biomarkers for OC, including C3, 32 MPO, 33 LBP, 34 CD14, 35 APOA1, 36 APOA4, 37 IGFBP2, 38 LRG1, 39 and THBS1, 40 while others, to the best of our knowledge, were identified as potential OC serum biomarkers for the first time in the current study. To evaluate diagnostic values of the 18 diagnostic biomarkers for HGSOC, we developed a multi-biomarker predictive model for discriminating between HGSOC and HCs in the validation cohort.…”

“…For the dual online LC system, two solid-phase extraction (SPE) columns (150 μm × 3 cm) and two analytical columns (75 μm × 150 cm) were manufactured in-house packed using Jupiter C18 materials (3 μm, 300 Å, Phenomenex) and were heated at 60 °C. 12 The serum peptides (25,40, or 50 μg) from each pooled sample group were injected and separated on the mid-pH column for the online first dimensional separation (Table S2). A mid-pH solvent A (10 mM TEAB in water, pH 7.5) and a mid-pH solvent B (10 mM TEAB in 99% ACN, pH 7.5) were used to generate a gradient (1−50% solvent B for 120 min at a flow rate of 1 μL/min).…”

Quantitative Plasma Proteomics to Identify Candidate Biomarkers of Relapse in Pediatric/Adolescent Hodgkin Lymphoma

“…To date LC-MS-based quantitative proteomics analytical workflow allowed to discover several novel potential cancer biomarkers in serum/plasma for clinical application (reviewed by [ 15 ]): for instance, recently, altered protein abundances were found in non-Hodgkin lymphoma, infected or not by human immunodeficiency virus, (i.e., C1Q and B2M) [ 34 ]; predicted the outcome of breast cancer patients receiving neodiuvant chemotherapy (APOC3, MBL2, ENG and P4HB) [ 35 ] or associated with high risk of ovarian cancer in BRCA1/2 carriers (SPARC and THBS1) [ 20 ].…”

“…In label-free LC-MS/MS approaches, the relative abundance of different proteins is measured from mass spectral peak intensities or by spectral counting [ 17 ], and protein expression patterns can be compared across samples. Using this approach has enabled the discovery of numerous potential biomarkers (e.g., [ 18 , 19 , 20 ]). In the present work, label-free LC-MS/MS was used to identify circulating biomarkers capable of predicting relapse in a case/control study on 42 children with HL treated according to the European Network for Pediatric Hodgkin Lymphoma (EuroNet-PHL) C2 protocol (NCT02684708).…”

Plasma Proteome Signature to Predict the Outcome of Breast Cancer Patients Receiving Neoadjuvant Chemotherapy

“…The normalized quantitative values of the remaining proteins except for the four proteins were derived by dividing the raw protein quantitative values in each sample by the NSF. The details of this method are described in previous studies [ 66 , 67 , 68 ].…”