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Enhanced Therapeutic Efficacy in Cancer Patients by Short-term Fasting: The Autophagy Connection

Preclinical studies suggest that fasting prior to chemotherapy may be an effective strategy to protect patients against the adverse effects of chemo-toxicity. Fasting may also sensitize cancer cells to chemotherapy. It is further suggested that fasting may similarly augment the efficacy of oncolytic...

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Autores principales: van Niekerk, Gustav, Hattingh, Suzèl M., Engelbrecht, Anna-Mart
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5107564/
https://www.ncbi.nlm.nih.gov/pubmed/27896219
http://dx.doi.org/10.3389/fonc.2016.00242
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author van Niekerk, Gustav
Hattingh, Suzèl M.
Engelbrecht, Anna-Mart
author_facet van Niekerk, Gustav
Hattingh, Suzèl M.
Engelbrecht, Anna-Mart
author_sort van Niekerk, Gustav
collection PubMed
description Preclinical studies suggest that fasting prior to chemotherapy may be an effective strategy to protect patients against the adverse effects of chemo-toxicity. Fasting may also sensitize cancer cells to chemotherapy. It is further suggested that fasting may similarly augment the efficacy of oncolytic viral therapy. The primary mechanism mediating these beneficial effects is thought to relate to the fact that fasting results in a decrease of circulating growth factors. In turn, such fasting cues would prompt normal cells to redirect energy toward cell maintenance and repair processes, rather than growth and proliferation. However, fasting is also known to upregulate autophagy, an evolutionarily conserved catabolic process that is upregulated in response to various cell stressors. Here, we review a number of mechanisms by which fasting-induced autophagy may have an impact on both chemo-tolerance and chemo-sensitization. First, fasting may exert a protective effect by mobilizing autophagic components prior to chemo-induction. In turn, the autophagic apparatus can be repurposed for removing cellular components damaged by chemotherapy. Autophagy also plays a key role in epitope expression as well as in modulating inflammation. Chemo-sensitization resulting from fasting may in fact be an effect of enhanced immune surveillance as a result of better autophagy-dependent epitope processing. Finally, autophagy is involved in host defense against viruses, and aspects of the autophagic process are also often targets for viral subversion. Consequently, altering autophagic flux by fasting may alter viral infectivity. These observations suggest that fasting-induced autophagy may have an impact on therapeutic efficacy in various oncological contexts.
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spelling pubmed-51075642016-11-28 Enhanced Therapeutic Efficacy in Cancer Patients by Short-term Fasting: The Autophagy Connection van Niekerk, Gustav Hattingh, Suzèl M. Engelbrecht, Anna-Mart Front Oncol Oncology Preclinical studies suggest that fasting prior to chemotherapy may be an effective strategy to protect patients against the adverse effects of chemo-toxicity. Fasting may also sensitize cancer cells to chemotherapy. It is further suggested that fasting may similarly augment the efficacy of oncolytic viral therapy. The primary mechanism mediating these beneficial effects is thought to relate to the fact that fasting results in a decrease of circulating growth factors. In turn, such fasting cues would prompt normal cells to redirect energy toward cell maintenance and repair processes, rather than growth and proliferation. However, fasting is also known to upregulate autophagy, an evolutionarily conserved catabolic process that is upregulated in response to various cell stressors. Here, we review a number of mechanisms by which fasting-induced autophagy may have an impact on both chemo-tolerance and chemo-sensitization. First, fasting may exert a protective effect by mobilizing autophagic components prior to chemo-induction. In turn, the autophagic apparatus can be repurposed for removing cellular components damaged by chemotherapy. Autophagy also plays a key role in epitope expression as well as in modulating inflammation. Chemo-sensitization resulting from fasting may in fact be an effect of enhanced immune surveillance as a result of better autophagy-dependent epitope processing. Finally, autophagy is involved in host defense against viruses, and aspects of the autophagic process are also often targets for viral subversion. Consequently, altering autophagic flux by fasting may alter viral infectivity. These observations suggest that fasting-induced autophagy may have an impact on therapeutic efficacy in various oncological contexts. Frontiers Media S.A. 2016-11-14 /pmc/articles/PMC5107564/ /pubmed/27896219 http://dx.doi.org/10.3389/fonc.2016.00242 Text en Copyright © 2016 van Niekerk, Hattingh and Engelbrecht. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Oncology
van Niekerk, Gustav
Hattingh, Suzèl M.
Engelbrecht, Anna-Mart
Enhanced Therapeutic Efficacy in Cancer Patients by Short-term Fasting: The Autophagy Connection
title Enhanced Therapeutic Efficacy in Cancer Patients by Short-term Fasting: The Autophagy Connection
title_full Enhanced Therapeutic Efficacy in Cancer Patients by Short-term Fasting: The Autophagy Connection
title_fullStr Enhanced Therapeutic Efficacy in Cancer Patients by Short-term Fasting: The Autophagy Connection
title_full_unstemmed Enhanced Therapeutic Efficacy in Cancer Patients by Short-term Fasting: The Autophagy Connection
title_short Enhanced Therapeutic Efficacy in Cancer Patients by Short-term Fasting: The Autophagy Connection
title_sort enhanced therapeutic efficacy in cancer patients by short-term fasting: the autophagy connection
topic Oncology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5107564/
https://www.ncbi.nlm.nih.gov/pubmed/27896219
http://dx.doi.org/10.3389/fonc.2016.00242
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