Serum FAP⁺ exosome-based flow cytometric detection: potential utility in early diagnosis, disease progression assessment, and surgical response monitoring of lung adenocarcinoma.

Authors

Ming Liu, Xiamin He, Jing Chen, Juan Huang, Xiang Lv, Guanghua Liu, Yijing Cai, Yanhui Lin, Yaocheng Wang, Yingying Cao, Minjian Huang, Rongzhao Zhang, Lilan Zhao, Jianlin Chen, Chundong Yu, Hao Zhang, Fangqin Xue, Yi Huang

Published in

Journal of nanobiotechnology. Jun 19, 2026. Epub Jun 19, 2026.

Abstract

Lung adenocarcinoma (LUAD) remains a leading cause of cancer-related mortality, and currently available serum biomarkers have limited sensitivity and specificity for early diagnosis. We investigated whether serum fibroblast activation protein-positive (FAP⁺) exosomes could serve as a minimally invasive biomarker for LUAD.
We examined FAP expression and exosomal localization in cancer-associated fibroblasts (CAFs), evaluated a magnetic bead-based strategy for enriching FAP⁺ exosomes, and established a latex bead-based flow cytometric assay using biotinylated anti-FAP antibody and streptavidin-PE detection. The assay was then evaluated in healthy donors (HD), patients with benign lung lesions (LBL), and patients with LUAD, and its diagnostic performance was compared with conventional serum biomarkers, including CEA, NSE, and CYFRA21-1.
Exosomes released by CAFs showed elevated FAP expression, and FAP was associated with the exosomal marker CD9, supporting a possible CD9-associated exosomal sorting mechanism. In the clinical cohort, serum FAP⁺ exosome levels were significantly higher in LUAD than in HD and LBL, and increased with disease stage. In early-stage LUAD, serum FAP⁺ exosomes showed favorable diagnostic performance, with an AUC of 0.932, 88.4% sensitivity, and 87.6% specificity. Compared with conventional serum biomarkers, including CEA, NSE, and CYFRA21-1, serum FAP⁺ exosomes showed superior diagnostic performance in this cohort, while combined biomarker models provided only modest incremental improvement over FAP⁺ exosomes alone. Serum FAP⁺ exosome levels also decreased significantly after surgery, suggesting that this marker may reflect early postoperative changes.
This study provides evidence that FAP is enriched in exosomes released by CAFs and may be incorporated into exosomes through a CD9-associated mechanism. We further established a serum FAP⁺ exosome-based flow cytometric assay that may serve as a promising minimally invasive strategy for LUAD diagnosis, disease progression assessment, and early postoperative monitoring.

PMID:
42321804
Bibliographic data and abstract were imported from PubMed on 20 Jun 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.