Overcoming intra-tumoral heterogeneity for biomarker discovery in the high-grade serous ovarian cancer proteome.

Improved biomarkers of treatment response are needed for patients with high-grade serous ovarian cancer (HGSC). A challenge is substantial anatomical site-to-site variation in expression. We completed data-independent acquisition-mass spectrometry (DIA-MS) analysis of 404 fresh frozen and 78 formalin-fixed, paraffin-embedded HGSC tissue samples from the ovary (adnexal) and a common secondary site (omentum) in 11 patients.

Federated Deep Learning Enables Cancer Subtyping by Proteomics.

Unlabelled: Artificial intelligence applications in biomedicine face major challenges from data privacy requirements. To address this issue for clinically annotated tissue proteomic data, we developed a federated deep learning approach (ProCanFDL), training local models on simulated sites containing data from a pan-cancer cohort (n = 1,260) and 29 cohorts held behind private firewalls (n = 6,265), representing 19,930 replicate data-independent acquisition mass spectrometry runs. Local parameter updates were aggregated to build the global model, achieving a 43% performance gain on the hold-out test set (n = 625) in 14 cancer subtyping tasks compared with local models and matching centralized model performance.

A Proteomic Signature for Human Papillomavirus-Associated Oropharyngeal Squamous Cell Carcinoma Predicts Patients at High Risk of Recurrence.

Abstract: Although human papillomavirus (HPV)–positive oropharyngeal squamous cell carcinoma (OPSCC) is associated with better prognosis than HPV-negative disease, ∼30% of cases relapse despite curative-intent radiotherapy (±chemotherapy). We aimed to develop a proteomic signature associated with risk of recurrence within HPV+OPSCC. We analyzed tumor specimens from 124 patients with T1–4N0–3M0 HPV+OPSCC: 50 patients with residual or recurrent disease within 5 years of treatment and 74 age and performance status–matched patients with no recurrence.

High-Throughput Proteomics and Phosphoproteomics of Rat Tissues Using Microflow Zeno SWATH.

High-throughput tissue proteomics has great potential in the advancement of precision medicine. Here, we investigated the combined sensitivity of trap-elute microflow liquid chromatography with a ZenoTOF for DIA proteomics and phosphoproteomics. Method optimization was conducted on HEK293T cell lines to determine the optimal variable window size, MS2 accumulation time and gradient length.

Heat 'n Beat: A Universal High-Throughput End-to-End Proteomics Sample Processing Platform in under an Hour.

Proteomic analysis by mass spectrometry of small (≤2 mg) solid tissue samples from diverse formats requires high throughput and comprehensive proteome coverage. We developed a nearly universal, rapid, and robust protocol for sample preparation, suitable for high-throughput projects that encompass most cell or tissue types. This end-to-end workflow extends from original sample to loading the mass spectrometer and is centered on a one-tube homogenization and digestion method called Heat 'n Beat (HnB).

Strategies to enable large-scale proteomics for reproducible research.

Reproducible research is the bedrock of experimental science. To enable the deployment of large-scale proteomics, we assess the reproducibility of mass spectrometry (MS) over time and across instruments and develop computational methods for improving quantitative accuracy. We perform 1560 data independent acquisition (DIA)-MS runs of eight samples containing known proportions of ovarian and prostate cancer tissue and yeast, or control HEK293T cells.

Accelerated Barocycler Lysis and Extraction Sample Preparation for Clinical Proteomics by Mass Spectrometry.

We have developed a streamlined proteomic sample preparation protocol termed Accelerated Barocycler Lysis and Extraction (ABLE) that substantially reduces the time and cost of tissue sample processing. ABLE is based on pressure cycling technology (PCT) for rapid tissue solubilization and reliable, controlled proteolytic digestion. Here, a previously reported PCT based protocol was optimized using 1-4 mg biopsy punches from rat kidney.

Identification of proteins from 4200-year-old skin and muscle tissue biopsies from ancient Egyptian mummies of the first intermediate period shows evidence of acute inflammation and severe immune response.

We performed proteomics analysis on four skin and one muscle tissue samples taken from three ancient Egyptian mummies of the first intermediate period, approximately 4200 years old. The mummies were first dated by radiocarbon dating of the accompany-\break ing textiles, and morphologically examined by scanning electron microscopy of additional skin samples. Proteins were extracted, separated on SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) gels, and in-gel digested with trypsin.

Analytical performance of nano-LC-SRM using nondepleted human plasma over an 18-month period.

A standardized procedure for label-free nano-LC-SRM analysis of 32 high-medium abundance proteins from nondepleted human plasma was established and SRM data were acquired on 45 separate days for a control sample that was independently prepared on 39 distinct dates over an 18-month period (542 days). This case study enabled us to assess quantitative variance associated with nano-LC-SRM plasma analysis, mimicking experimental conditions that would be experienced with clinical trial biomarker studies. We assessed sample preparation variability attributed to different technicians and sample storage stability.

Age-related cleavages of crystallins in human lens cortical fiber cells generate a plethora of endogenous peptides and high molecular weight complexes.

Low molecular weight peptides derived from the breakdown of crystallins have been reported in adult human lenses. The proliferation of these LMW peptides coincides with the earliest stages of cataract formation, suggesting that the protein cleavages involved may contribute to the aggregation and insolubilization of crystallins. This study reports the identification of 238 endogenous LMW crystallin peptides from the cortical extracts of four human lenses representing young, middle and old-age human lenses.

Phosphoproteomic Analysis of Cell-Based Resistance to BRAF Inhibitor Therapy in Melanoma.

The treatment of melanoma by targeted inhibition of the mutated kinase BRAF with small molecules only temporarily suppresses metastatic disease. In the face of chemical inhibition tumor plasticity, both innate and adaptive, promotes survival through the biochemical and genetic reconfiguration of cellular pathways that can engage proliferative and migratory systems. To investigate this process, high-resolution mass spectrometry was used to characterize the phosphoproteome of this transition in vitro.

Molecular signatures of long-lived proteins: autolytic cleavage adjacent to serine residues.

The centre of the human lens, which is composed of proteins that were synthesized prior to birth, is an ideal model for the evaluation of long-term protein stability and processes responsible for the degradation of macromolecules. By analysing the sequences of peptides present in human lens nuclei, characteristic features of intrinsic protein instability were determined. Prominent was the cleavage on the N-terminal side of serine residues.