Dataset Information

Evaluation of the potential of Pap test fluid and cervical swabs to serve as clinical diagnostic biospecimens for the detection of ovarian cancer by mass spectrometry-based proteomics.

ABSTRACT:

Background

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.

Methods

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.

Results

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.

Conclusions

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.

SUBMITTER: Boylan KLM

PROVIDER: S-EPMC7792339 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature

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Publications

Evaluation of the potential of Pap test fluid and cervical swabs to serve as clinical diagnostic biospecimens for the detection of ovarian cancer by mass spectrometry-based proteomics.

Boylan Kristin L M KLM Afiuni-Zadeh Somaieh S Geller Melissa A MA Argenta Peter A PA Griffin Timothy J TJ Skubitz Amy P N APN

Clinical proteomics 20210107 1

<h4>Background</h4>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.<h4>Methods</h4>Proteins were concentrated by acetone precipitation from th ...[more]

PMID: 33413078

Similar Datasets

Project description:BackgroundThe proteomic analysis of body fluids is a growing technology for the identification of protein biomarkers of disease. Given that Papanicolaou tests (Pap tests) are routinely performed on over 30 million women annually in the U.S. to screen for cervical cancer, we examined the residual Pap test fluid as a source of protein for analysis by mass spectrometry (MS). In the liquid-based Pap test, cervical cells are collected from the ectocervix and placed into an alcohol-based fixative prior to staining and pathologic examination. We hypothesized that proteins shed by cells of the female genital tract can be detected in the Pap test fixative by MS-based proteomic techniques. We examined the feasibility of using residual fluid from discarded Pap tests with cytologically "normal" results to optimize sample preparation for MS analysis. The protein composition of the cell-free Pap test fluid was determined by silver staining of sodium dodecyl sulfate -polyacrylamide gels, and the abundance of serum proteins was examined by Western immunoblot using an antibody against human serum albumin. Both pooled and individual samples were trypsin digested and analyzed by two-dimensional MS/MS. Proteins were identified by searching against the Human Uniprot database, and characterized for localization, function and relative abundance.ResultsThe average volume of the residual Pap test fluid was 1.5 ml and the average protein concentration was 0.14 mg/ml. By Western immunoblot we showed that the amount of albumin in each sample was significantly reduced compared to normal serum. By MS/MS, we identified 714 unique proteins in pooled Pap test samples and an average of 431 proteins in individual samples. About 40% of the proteins identified were extracellular or localized to the plasma membrane. Almost 20% of the proteins identified were involved in immunity and defense, characteristic of the healthy cervical-vaginal proteome. By merging the protein sets from the individual and pooled Pap test samples, we created a "Normal Pap test Core Proteome" consisting of 153 proteins.ConclusionsResidual Pap test fluid contains a sufficient amount of protein for analysis by MS and represents a valuable biospecimen source for the identification of protein biomarkers for gynecological diseases.

Project description:BackgroundDetermining cervical precancer risk among human immunodeficiency virus (HIV)-infected women who despite a normal Pap test are positive for oncogenic human papillomavirus (oncHPV) types is important for setting screening practices.MethodsA total of 2791 HIV-infected and 975 HIV-uninfected women in the Women's Interagency HIV Study were followed semiannually with Pap tests and colposcopy. Cumulative risks of cervical intraepithelial neoplasia grade 2 or greater (CIN-2+; threshold used for CIN treatment) and grade 3 or greater (CIN-3+; threshold to set screening practices) were measured in HIV-infected and HIV-uninfected women with normal Pap tests, stratified by baseline HPV results, and also in HIV-infected women with a low-grade squamous intraepithelial lesion (LSIL; benchmark indication for colposcopy).ResultsAt baseline, 1021 HIV-infected and 518 HIV-uninfected women had normal Pap tests, of whom 154 (15%) and 27 (5%), respectively, tested oncHPV positive. The 5-year CIN-2+ cumulative risk in the HIV-infected oncHPV-positive women was 22% (95% confidence interval [CI], 9%-34%), 12% (95% CI, 0%-22%), and 14% (95% CI, 2%-25%) among those with CD4 counts <350, 350-499, and ≥500 cells/µL, respectively, whereas it was 10% (95% CI, 0%-21%) in those without HIV. For CIN-3+, the cumulative risk averaged 4% (95% CI, 1%-8%) in HIV-infected oncHPV-positive women, and 10% (95% CI, 0%-23%) among those positive for HPV type 16. In HIV-infected women with LSIL, CIN-3+ risk was 7% (95% CI, 3%-11%). In multivariate analysis, HIV-infected HPV16-positive women had 13-fold (P = .001) greater CIN-3+ risk than oncHPV-negative women (referent), and HIV-infected women with LSIL had 9-fold (P < .0001) greater risk.ConclusionsHIV-infected women with a normal Pap result who test HPV16 positive have high precancer risk (similar to those with LSIL), possibly warranting immediate colposcopy. Repeat screening in 1 year may be appropriate if non-16 oncHPV is detected.

Dataset Information

Evaluation of the potential of Pap test fluid and cervical swabs to serve as clinical diagnostic biospecimens for the detection of ovarian cancer by mass spectrometry-based proteomics.

Background

Methods

Results

Conclusions

Publications

Evaluation of the potential of Pap test fluid and cervical swabs to serve as clinical diagnostic biospecimens for the detection of ovarian cancer by mass spectrometry-based proteomics.

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