Evidence map›Paper›PMID 42437885›Full record

ArticleClinical proteomics2026

Targeted proteomics for the detection of androgen receptor variants in preclinical models of castration-resistant prostate cancer.

Zoi E Sychev, Gabrianne Larson, Megan L Ludwig, Seiei Shiba, Kiel Tietz, Joshua W Russo, Steven Balk, Eva Corey, Stephen Plymate, Emmanuel S Antonarakis and 3 more

Abstract read
In one paragraph

Article in Clinical proteomics, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

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PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

13 authors.

Zoi E SychevDepartment of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, US. zvillasa@gmail.com.
Gabrianne LarsonDepartment of Pharmacology, University of Minnesota, Minneapolis, US.
Megan L LudwigDepartment of Pharmacology, University of Minnesota, Minneapolis, US.
Seiei ShibaAdvance Research Diagnostic Laboratory, University of Minnesota, Minneapolis, US.
Kiel TietzMasonic Cancer Center, University of Minnesota, Minneapolis, US.
Joshua W RussoDepartment of Medicine Division of Hematology and Oncology, Harvard Medical School Beth Israel Deaconess Medical Center, Boston, US.
Steven BalkDepartment of Medicine Division of Hematology and Oncology, Harvard Medical School Beth Israel Deaconess Medical Center, Boston, US.
Eva CoreyDepartment of Urology, University of Washington, Seattle, US.
Stephen PlymateDepartment of Geriatric Medicine, University of Washington, Seattle, US.
Emmanuel S AntonarakisMasonic Cancer Center, University of Minnesota, Minneapolis, US.
Scott M DehmDepartment of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, US.
Jesse C SeegmillerDepartment of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, US.
Justin M DrakeDepartment of Pharmacology, University of Minnesota, Minneapolis, US. jdrake@umn.edu.

Funding

DOD grants and Targets of Cancer Training Program Fellowship W81XWH-20-1-0402, T32 CA009138 (ZES).DOD PCRP Early Investigator Research Award W81XWH-22-1-0098
6 · The paper itself

Abstract

backgroundThe emergence of Androgen Receptor variants (AR-Vs) during hormonal treatment is believed to be one of the key mechanisms of resistance. AR-Vs lack the ligand-binding domain and function as constitutively active transcription factors, rendering AR-targeted endocrine-based therapeutics ineffective in tumors that express AR-Vs. The goal of this study was to develop a targeted multiplex assay to identify known and unexplored AR-V proteins and help guide the stratification of PCa patients based on their AR-V protein profiles.

methodsA targeted multiple reaction monitoring (MRM) assay using liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed to quantify total AR proteins using the AR N-terminal domain (AR-Nterm), a well-characterized AR splice variant AR-V7 (AR-V7), a putative, previously identified but uncharacterized protein isoform (AR-V12) and isoforms that code for an exon 3 duplicated junction seen in AR-V2 and AR- full length with two copies of exon 3. Specimens included three AR-positive PCa cell lines (22Rv1, VCaP16, LNCaP), two AR-negative PCa cell lines (PC3, DU145), and a patient-derived xenograft (PDX) model of CRPC. Endogenous target peptides were quantified according to tier-2 targeted mass spectrometry "fit-for-purpose" guidelines to ensure analytical rigor.

resultsAnalytical performance was characterized across a linearity range of 4.15 fmol to 4000 fmol followed by evaluations of precision, accuracy, selectivity, stability, ion suppression and repeatability studies. The overall coefficient of variation (CV) was < 20% across seven independent validation experiments. Endogenous AR-V peptides were accurately quantified using calibration curves, achieving acceptable linear regression coefficients (R

conclusionThis study establishes a robust, validated MRM targeted proteomics assay capable of reproducibly detecting and quantifying both known and previously uncharacterized AR-Vs at the protein level  . The assay demonstrated < 20% analytical variation at the lower limit of quantification of 4.25 femtomole (fmol) for AR-Nterm and 8.25 fmol for AR-V7, AR Exon3-Dup/AR-V2 and AR-V12 and, showed robust analytical performance in preclinical models and is ready for further evaluation in clinical specimens. This provides a clinically applicable platform for the comprehensive profiling of AR-V proteins in human subjects, enabling improved stratification of patients with CRPC and supporting precision therapeutic strategies.

Indexed as

Androgen receptorCastration resistantProstate cancerProteomicsTargetedVariants

Identifiers

PMID42437885
PMCPMC13670591

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.