Cargando…
Using in vivo fluorescence lifetime imaging to detect HER2-positive tumors
BACKGROUND: Assessment of the status of tumor biomarkers in individual patients would facilitate personalizing treatment strategy, and continuous monitoring of those biomarkers and their binding process to the therapeutic drugs would provide a means for early evaluation of the efficacy of therapeuti...
Autores principales: | , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Springer Berlin Heidelberg
2018
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5884746/ https://www.ncbi.nlm.nih.gov/pubmed/29619584 http://dx.doi.org/10.1186/s13550-018-0384-6 |
_version_ | 1783311866774159360 |
---|---|
author | Ardeshirpour, Yasaman Sackett, Dan L. Knutson, Jay R. Gandjbakhche, Amir H. |
author_facet | Ardeshirpour, Yasaman Sackett, Dan L. Knutson, Jay R. Gandjbakhche, Amir H. |
author_sort | Ardeshirpour, Yasaman |
collection | PubMed |
description | BACKGROUND: Assessment of the status of tumor biomarkers in individual patients would facilitate personalizing treatment strategy, and continuous monitoring of those biomarkers and their binding process to the therapeutic drugs would provide a means for early evaluation of the efficacy of therapeutic intervention. Fluorescent probes can accumulate inside the tumor region due to the leakiness of its vascularization and this can make it difficult to distinguish if the measured fluorescence intensity is from probes bound to target receptors or just accumulated unbound probes inside the tumor. In this paper, we have studied the fluorescence lifetime as a means to distinguish bound HER2 specific affibody probes to HER2 receptors. Our imaging system is a time-resolved fluorescence system using a Ti-Sapphire femtosecond pulse laser as source and Time correlated Single photon Counting (TCSPC) system as detector for calculating the lifetime of the contrast agent. HER2-specific Affibody (His6-ZHER2:GS-Cys) (Affibody, Stockholm, Sweden) conjugated with a Dylight750 fluorescent probe (Thermo-Fisher-Scientific, Waltham, Massachusetts) was used as contrast agent and six human cancer cell lines, BT-474, SKOV-3, NCI-N87, MDA-MB-361, MCF-7, and MDA-MB-468, known to express different levels of HER2/neu, are used in athymic mice xenografts. RESULTS: By comparing the lifetime of unbound contrast agent (at the contralateral site) to the fluorescence lifetime at the tumor site, our results show that the fluorescence lifetime decreases as HER2 specific Affibody probes bind to the tumor receptors. A decrease of ~15% (100ps) in tumor fluorescence lifetime was observed in tumors with mid to high HER2 expression. Smaller decreases were observed in tumors with low-level of HER2 receptors and no change was observed in the non-HER2-expressing tumors. CONCLUSIONS: Using HER2-specific Affibody conjugated with the Dylight750 fluorescent probe as contrast agent, we demonstrated in live animals that change in fluorescence lifetime of the bound contrast agent can be used to assess the high to mid-level expression of HER2 expressing tumors in-vivo in only one measurement. The rationale is that the fluorescence lifetime of our specific probe is sensitive to affinity to, and specific interaction with, other molecules. |
format | Online Article Text |
id | pubmed-5884746 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Springer Berlin Heidelberg |
record_format | MEDLINE/PubMed |
spelling | pubmed-58847462018-04-09 Using in vivo fluorescence lifetime imaging to detect HER2-positive tumors Ardeshirpour, Yasaman Sackett, Dan L. Knutson, Jay R. Gandjbakhche, Amir H. EJNMMI Res Original Research BACKGROUND: Assessment of the status of tumor biomarkers in individual patients would facilitate personalizing treatment strategy, and continuous monitoring of those biomarkers and their binding process to the therapeutic drugs would provide a means for early evaluation of the efficacy of therapeutic intervention. Fluorescent probes can accumulate inside the tumor region due to the leakiness of its vascularization and this can make it difficult to distinguish if the measured fluorescence intensity is from probes bound to target receptors or just accumulated unbound probes inside the tumor. In this paper, we have studied the fluorescence lifetime as a means to distinguish bound HER2 specific affibody probes to HER2 receptors. Our imaging system is a time-resolved fluorescence system using a Ti-Sapphire femtosecond pulse laser as source and Time correlated Single photon Counting (TCSPC) system as detector for calculating the lifetime of the contrast agent. HER2-specific Affibody (His6-ZHER2:GS-Cys) (Affibody, Stockholm, Sweden) conjugated with a Dylight750 fluorescent probe (Thermo-Fisher-Scientific, Waltham, Massachusetts) was used as contrast agent and six human cancer cell lines, BT-474, SKOV-3, NCI-N87, MDA-MB-361, MCF-7, and MDA-MB-468, known to express different levels of HER2/neu, are used in athymic mice xenografts. RESULTS: By comparing the lifetime of unbound contrast agent (at the contralateral site) to the fluorescence lifetime at the tumor site, our results show that the fluorescence lifetime decreases as HER2 specific Affibody probes bind to the tumor receptors. A decrease of ~15% (100ps) in tumor fluorescence lifetime was observed in tumors with mid to high HER2 expression. Smaller decreases were observed in tumors with low-level of HER2 receptors and no change was observed in the non-HER2-expressing tumors. CONCLUSIONS: Using HER2-specific Affibody conjugated with the Dylight750 fluorescent probe as contrast agent, we demonstrated in live animals that change in fluorescence lifetime of the bound contrast agent can be used to assess the high to mid-level expression of HER2 expressing tumors in-vivo in only one measurement. The rationale is that the fluorescence lifetime of our specific probe is sensitive to affinity to, and specific interaction with, other molecules. Springer Berlin Heidelberg 2018-04-04 /pmc/articles/PMC5884746/ /pubmed/29619584 http://dx.doi.org/10.1186/s13550-018-0384-6 Text en © The Author(s). 2018 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. |
spellingShingle | Original Research Ardeshirpour, Yasaman Sackett, Dan L. Knutson, Jay R. Gandjbakhche, Amir H. Using in vivo fluorescence lifetime imaging to detect HER2-positive tumors |
title | Using in vivo fluorescence lifetime imaging to detect HER2-positive tumors |
title_full | Using in vivo fluorescence lifetime imaging to detect HER2-positive tumors |
title_fullStr | Using in vivo fluorescence lifetime imaging to detect HER2-positive tumors |
title_full_unstemmed | Using in vivo fluorescence lifetime imaging to detect HER2-positive tumors |
title_short | Using in vivo fluorescence lifetime imaging to detect HER2-positive tumors |
title_sort | using in vivo fluorescence lifetime imaging to detect her2-positive tumors |
topic | Original Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5884746/ https://www.ncbi.nlm.nih.gov/pubmed/29619584 http://dx.doi.org/10.1186/s13550-018-0384-6 |
work_keys_str_mv | AT ardeshirpouryasaman usinginvivofluorescencelifetimeimagingtodetecther2positivetumors AT sackettdanl usinginvivofluorescencelifetimeimagingtodetecther2positivetumors AT knutsonjayr usinginvivofluorescencelifetimeimagingtodetecther2positivetumors AT gandjbakhcheamirh usinginvivofluorescencelifetimeimagingtodetecther2positivetumors |