Cargando…

Three-dimensional tumor spheroids for in vitro analysis of bacteria as gene delivery vectors in tumor therapy

BACKGROUND: Several studies in animal models demonstrated that obligate and facultative anaerobic bacteria of the genera Bifidobacterium, Salmonella, or Clostridium specifically colonize solid tumors. Consequently, these and other bacteria are discussed as live vectors to deliver therapeutic genes t...

Descripción completa

Detalles Bibliográficos
Autores principales: Osswald, Annika, Sun, Zhongke, Grimm, Verena, Ampem, Grace, Riegel, Karin, Westendorf, Astrid M., Sommergruber, Wolfgang, Otte, Kerstin, Dürre, Peter, Riedel, Christian U.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4676896/
https://www.ncbi.nlm.nih.gov/pubmed/26655167
http://dx.doi.org/10.1186/s12934-015-0383-5
_version_ 1782405252444585984
author Osswald, Annika
Sun, Zhongke
Grimm, Verena
Ampem, Grace
Riegel, Karin
Westendorf, Astrid M.
Sommergruber, Wolfgang
Otte, Kerstin
Dürre, Peter
Riedel, Christian U.
author_facet Osswald, Annika
Sun, Zhongke
Grimm, Verena
Ampem, Grace
Riegel, Karin
Westendorf, Astrid M.
Sommergruber, Wolfgang
Otte, Kerstin
Dürre, Peter
Riedel, Christian U.
author_sort Osswald, Annika
collection PubMed
description BACKGROUND: Several studies in animal models demonstrated that obligate and facultative anaerobic bacteria of the genera Bifidobacterium, Salmonella, or Clostridium specifically colonize solid tumors. Consequently, these and other bacteria are discussed as live vectors to deliver therapeutic genes to inhibit tumor growth. Therapeutic approaches for cancer treatment using anaerobic bacteria have been investigated in different mouse models. In the present study, solid three-dimensional (3D) multicellular tumor spheroids (MCTS) of the colorectal adenocarcinoma cell line HT-29 were generated and tested for their potential to study prodrug-converting enzyme therapies using bacterial vectors in vitro. RESULTS: HT-29 MCTS resembled solid tumors displaying all relevant features with an outer zone of proliferating cells and hypoxic and apoptotic regions in the core. Upon incubation with HT-29 MCTS, Bifidobacterium bifidum S17 and Salmonella typhimurium YB1 selectively localized, survived and replicated in hypoxic areas inside MCTS. Furthermore, spores of the obligate anaerobe Clostridium sporogenes germinated in these hypoxic areas. To further evaluate the potential of MCTS to investigate therapeutic approaches using bacteria as gene delivery vectors, recombinant bifidobacteria expressing prodrug-converting enzymes were used. Expression of a secreted cytosine deaminase in combination with 5-fluorocytosine had no effect on growth of MCTS due to an intrinsic resistance of HT-29 cells to 5-fluorouracil, i.e. the converted drug. However, a combination of the prodrug CB1954 and a strain expressing a secreted chromate reductase effectively inhibited MCTS growth. CONCLUSIONS: Collectively, the presented results indicate that MCTS are a suitable and reliable model to investigate live bacteria as gene delivery vectors for cancer therapy in vitro. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12934-015-0383-5) contains supplementary material, which is available to authorized users.
format Online
Article
Text
id pubmed-4676896
institution National Center for Biotechnology Information
language English
publishDate 2015
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-46768962015-12-13 Three-dimensional tumor spheroids for in vitro analysis of bacteria as gene delivery vectors in tumor therapy Osswald, Annika Sun, Zhongke Grimm, Verena Ampem, Grace Riegel, Karin Westendorf, Astrid M. Sommergruber, Wolfgang Otte, Kerstin Dürre, Peter Riedel, Christian U. Microb Cell Fact Technical Notes BACKGROUND: Several studies in animal models demonstrated that obligate and facultative anaerobic bacteria of the genera Bifidobacterium, Salmonella, or Clostridium specifically colonize solid tumors. Consequently, these and other bacteria are discussed as live vectors to deliver therapeutic genes to inhibit tumor growth. Therapeutic approaches for cancer treatment using anaerobic bacteria have been investigated in different mouse models. In the present study, solid three-dimensional (3D) multicellular tumor spheroids (MCTS) of the colorectal adenocarcinoma cell line HT-29 were generated and tested for their potential to study prodrug-converting enzyme therapies using bacterial vectors in vitro. RESULTS: HT-29 MCTS resembled solid tumors displaying all relevant features with an outer zone of proliferating cells and hypoxic and apoptotic regions in the core. Upon incubation with HT-29 MCTS, Bifidobacterium bifidum S17 and Salmonella typhimurium YB1 selectively localized, survived and replicated in hypoxic areas inside MCTS. Furthermore, spores of the obligate anaerobe Clostridium sporogenes germinated in these hypoxic areas. To further evaluate the potential of MCTS to investigate therapeutic approaches using bacteria as gene delivery vectors, recombinant bifidobacteria expressing prodrug-converting enzymes were used. Expression of a secreted cytosine deaminase in combination with 5-fluorocytosine had no effect on growth of MCTS due to an intrinsic resistance of HT-29 cells to 5-fluorouracil, i.e. the converted drug. However, a combination of the prodrug CB1954 and a strain expressing a secreted chromate reductase effectively inhibited MCTS growth. CONCLUSIONS: Collectively, the presented results indicate that MCTS are a suitable and reliable model to investigate live bacteria as gene delivery vectors for cancer therapy in vitro. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12934-015-0383-5) contains supplementary material, which is available to authorized users. BioMed Central 2015-12-12 /pmc/articles/PMC4676896/ /pubmed/26655167 http://dx.doi.org/10.1186/s12934-015-0383-5 Text en © Osswald et al. 2015 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. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Technical Notes
Osswald, Annika
Sun, Zhongke
Grimm, Verena
Ampem, Grace
Riegel, Karin
Westendorf, Astrid M.
Sommergruber, Wolfgang
Otte, Kerstin
Dürre, Peter
Riedel, Christian U.
Three-dimensional tumor spheroids for in vitro analysis of bacteria as gene delivery vectors in tumor therapy
title Three-dimensional tumor spheroids for in vitro analysis of bacteria as gene delivery vectors in tumor therapy
title_full Three-dimensional tumor spheroids for in vitro analysis of bacteria as gene delivery vectors in tumor therapy
title_fullStr Three-dimensional tumor spheroids for in vitro analysis of bacteria as gene delivery vectors in tumor therapy
title_full_unstemmed Three-dimensional tumor spheroids for in vitro analysis of bacteria as gene delivery vectors in tumor therapy
title_short Three-dimensional tumor spheroids for in vitro analysis of bacteria as gene delivery vectors in tumor therapy
title_sort three-dimensional tumor spheroids for in vitro analysis of bacteria as gene delivery vectors in tumor therapy
topic Technical Notes
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4676896/
https://www.ncbi.nlm.nih.gov/pubmed/26655167
http://dx.doi.org/10.1186/s12934-015-0383-5
work_keys_str_mv AT osswaldannika threedimensionaltumorspheroidsforinvitroanalysisofbacteriaasgenedeliveryvectorsintumortherapy
AT sunzhongke threedimensionaltumorspheroidsforinvitroanalysisofbacteriaasgenedeliveryvectorsintumortherapy
AT grimmverena threedimensionaltumorspheroidsforinvitroanalysisofbacteriaasgenedeliveryvectorsintumortherapy
AT ampemgrace threedimensionaltumorspheroidsforinvitroanalysisofbacteriaasgenedeliveryvectorsintumortherapy
AT riegelkarin threedimensionaltumorspheroidsforinvitroanalysisofbacteriaasgenedeliveryvectorsintumortherapy
AT westendorfastridm threedimensionaltumorspheroidsforinvitroanalysisofbacteriaasgenedeliveryvectorsintumortherapy
AT sommergruberwolfgang threedimensionaltumorspheroidsforinvitroanalysisofbacteriaasgenedeliveryvectorsintumortherapy
AT ottekerstin threedimensionaltumorspheroidsforinvitroanalysisofbacteriaasgenedeliveryvectorsintumortherapy
AT durrepeter threedimensionaltumorspheroidsforinvitroanalysisofbacteriaasgenedeliveryvectorsintumortherapy
AT riedelchristianu threedimensionaltumorspheroidsforinvitroanalysisofbacteriaasgenedeliveryvectorsintumortherapy