Establishment of an Assay with Ultrahigh Sensitivity for Detecting sEV-Derived PD-L1 as a Serum Biomarker for Lung Cancer—A Pilot Study Using TN-cyclon™

Programmed death-ligand 1 (PD-L1) is an immune checkpoint protein. The soluble form of PD-L1 (sPD-L1) and PD-L1 derived from small extracellular vesicles (sEVPD-L1) are promising cancer biomarkers. While sEVPD-L1 in particular may contribute to immune evasion and is associated with a poor prognosis,...

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Main Authors: Kyo Okita, Hasumi Arita, Keita Sudo, Teruki Yoshimura, Etsuro Ito
Format: Article
Language:English
Published: MDPI AG 2025-07-01
Series:Current Issues in Molecular Biology
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Online Access:https://www.mdpi.com/1467-3045/47/7/564
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author Kyo Okita
Hasumi Arita
Keita Sudo
Teruki Yoshimura
Etsuro Ito
author_facet Kyo Okita
Hasumi Arita
Keita Sudo
Teruki Yoshimura
Etsuro Ito
author_sort Kyo Okita
collection DOAJ
description Programmed death-ligand 1 (PD-L1) is an immune checkpoint protein. The soluble form of PD-L1 (sPD-L1) and PD-L1 derived from small extracellular vesicles (sEVPD-L1) are promising cancer biomarkers. While sEVPD-L1 in particular may contribute to immune evasion and is associated with a poor prognosis, it exists only in trace amounts, making it difficult to detect using conventional enzyme-linked immunosorbent assay (ELISA) methods. Therefore, we developed an ultrasensitive detection method, TN-cyclon™. The TN-cyclon™ method combines sandwich ELISA with enzyme cycling amplification. We applied TN-cyclon™ to measure recombinant PD-L1 protein and sEVPD-L1 in serum samples from cancer patients and healthy donors. Recombinant PD-L1 protein was measured with an ultrasensitive detection limit of 0.172 pg/mL. In clinical specimens, sEVPD-L1 levels were significantly higher in lung cancer patients than in healthy donors, whereas sPD-L1 levels measured with a conventional ELISA did not differ significantly between groups. Our results demonstrated that the TN-cyclon™ method exhibits a 20-fold increase in sensitivity compared to a conventional ELISA. Although this is a pilot study, our new assay enables the detection of very low concentrations of sEVPD-L1 in serum that can be used to evaluate the predictive and prognostic performance of sEVPD-L1 in lung cancer patients in future studies.
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spelling doaj-art-87d94d090dfe40c0bdf01143a9b5a6922025-08-20T03:58:31ZengMDPI AGCurrent Issues in Molecular Biology1467-30371467-30452025-07-0147756410.3390/cimb47070564Establishment of an Assay with Ultrahigh Sensitivity for Detecting sEV-Derived PD-L1 as a Serum Biomarker for Lung Cancer—A Pilot Study Using TN-cyclon™Kyo Okita0Hasumi Arita1Keita Sudo2Teruki Yoshimura3Etsuro Ito4Department of Biology, TWIns, Waseda University, Shinjuku, Tokyo 162-0056, JapanDepartment of Biology, TWIns, Waseda University, Shinjuku, Tokyo 162-0056, JapanDepartment of Biology, TWIns, Waseda University, Shinjuku, Tokyo 162-0056, JapanR&D Department, BioPhenoMA Inc., Waseda University Entrepreneurship Center, Shinjuku, Tokyo 169-0051, JapanDepartment of Biology, TWIns, Waseda University, Shinjuku, Tokyo 162-0056, JapanProgrammed death-ligand 1 (PD-L1) is an immune checkpoint protein. The soluble form of PD-L1 (sPD-L1) and PD-L1 derived from small extracellular vesicles (sEVPD-L1) are promising cancer biomarkers. While sEVPD-L1 in particular may contribute to immune evasion and is associated with a poor prognosis, it exists only in trace amounts, making it difficult to detect using conventional enzyme-linked immunosorbent assay (ELISA) methods. Therefore, we developed an ultrasensitive detection method, TN-cyclon™. The TN-cyclon™ method combines sandwich ELISA with enzyme cycling amplification. We applied TN-cyclon™ to measure recombinant PD-L1 protein and sEVPD-L1 in serum samples from cancer patients and healthy donors. Recombinant PD-L1 protein was measured with an ultrasensitive detection limit of 0.172 pg/mL. In clinical specimens, sEVPD-L1 levels were significantly higher in lung cancer patients than in healthy donors, whereas sPD-L1 levels measured with a conventional ELISA did not differ significantly between groups. Our results demonstrated that the TN-cyclon™ method exhibits a 20-fold increase in sensitivity compared to a conventional ELISA. Although this is a pilot study, our new assay enables the detection of very low concentrations of sEVPD-L1 in serum that can be used to evaluate the predictive and prognostic performance of sEVPD-L1 in lung cancer patients in future studies.https://www.mdpi.com/1467-3045/47/7/564immune checkpointlung cancerPD-L1small extracellular vesicleultrasensitive ELISA
spellingShingle Kyo Okita
Hasumi Arita
Keita Sudo
Teruki Yoshimura
Etsuro Ito
Establishment of an Assay with Ultrahigh Sensitivity for Detecting sEV-Derived PD-L1 as a Serum Biomarker for Lung Cancer—A Pilot Study Using TN-cyclon™
Current Issues in Molecular Biology
immune checkpoint
lung cancer
PD-L1
small extracellular vesicle
ultrasensitive ELISA
title Establishment of an Assay with Ultrahigh Sensitivity for Detecting sEV-Derived PD-L1 as a Serum Biomarker for Lung Cancer—A Pilot Study Using TN-cyclon™
title_full Establishment of an Assay with Ultrahigh Sensitivity for Detecting sEV-Derived PD-L1 as a Serum Biomarker for Lung Cancer—A Pilot Study Using TN-cyclon™
title_fullStr Establishment of an Assay with Ultrahigh Sensitivity for Detecting sEV-Derived PD-L1 as a Serum Biomarker for Lung Cancer—A Pilot Study Using TN-cyclon™
title_full_unstemmed Establishment of an Assay with Ultrahigh Sensitivity for Detecting sEV-Derived PD-L1 as a Serum Biomarker for Lung Cancer—A Pilot Study Using TN-cyclon™
title_short Establishment of an Assay with Ultrahigh Sensitivity for Detecting sEV-Derived PD-L1 as a Serum Biomarker for Lung Cancer—A Pilot Study Using TN-cyclon™
title_sort establishment of an assay with ultrahigh sensitivity for detecting sev derived pd l1 as a serum biomarker for lung cancer a pilot study using tn cyclon™
topic immune checkpoint
lung cancer
PD-L1
small extracellular vesicle
ultrasensitive ELISA
url https://www.mdpi.com/1467-3045/47/7/564
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