TY - JOUR
T1 - Interferon- and STING-independent induction of type I interferon stimulated genes during fractionated irradiation
AU - Goedegebuure, Ruben S. A.
AU - Kleibeuker, Esther A.
AU - Buffa, Francesca M.
AU - Castricum, Kitty C. M.
AU - Haider, Syed
AU - Schulkens, Iris A.
AU - ten Kroode, Luuk
AU - van den Berg, Jaap
AU - Jacobs, Maarten A. J. M.
AU - van Berkel, Anne-Marie
AU - van Grieken, Nicole C. T.
AU - Derks, Sarah
AU - Slotman, Ben J.
AU - Verheul, Henk M. W.
AU - Harris, Adrian L.
AU - Thijssen, Victor L.
N1 - Publisher Copyright: © 2021, The Author(s). Copyright: Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/12/1
Y1 - 2021/12/1
N2 - Background: Improvement of radiotherapy efficacy requires better insight in the dynamic responses that occur during irradiation. Here, we aimed to identify the molecular responses that are triggered during clinically applied fractionated irradiation. Methods: Gene expression analysis was performed by RNAseq or microarray analysis of cancer cells or xenograft tumors, respectively, subjected to 3–5 weeks of 5 × 2 Gy/week. Validation of altered gene expression was performed by qPCR and/or ELISA in multiple cancer cell lines as well as in pre- and on-treatment biopsies from esophageal cancer patients (NCT02072720). Targeted protein inhibition and CRISPR/Cas-induced gene knockout was used to analyze the role of type I interferons and cGAS/STING signaling pathway in the molecular and cellular response to fractionated irradiation. Results: Gene expression analysis identified type I interferon signaling as the most significantly enriched biological process induced during fractionated irradiation. The commonality of this response was confirmed in all irradiated cell lines, the xenograft tumors and in biopsies from esophageal cancer patients. Time-course analyses demonstrated a peak in interferon-stimulated gene (ISG) expression within 2–3 weeks of treatment. The response was accompanied by a variable induction of predominantly interferon-beta and/or -lambda, but blocking these interferons did not affect ISG expression induction. The same was true for targeted inhibition of the upstream regulatory STING protein while knockout of STING expression only delayed the ISG expression induction. Conclusions: Collectively, the presented data show that clinically applied fractionated low-dose irradiation can induce a delayed type I interferon response that occurs independently of interferon expression or STING signaling. These findings have implications for current efforts that aim to target the type I interferon response for cancer treatment.
AB - Background: Improvement of radiotherapy efficacy requires better insight in the dynamic responses that occur during irradiation. Here, we aimed to identify the molecular responses that are triggered during clinically applied fractionated irradiation. Methods: Gene expression analysis was performed by RNAseq or microarray analysis of cancer cells or xenograft tumors, respectively, subjected to 3–5 weeks of 5 × 2 Gy/week. Validation of altered gene expression was performed by qPCR and/or ELISA in multiple cancer cell lines as well as in pre- and on-treatment biopsies from esophageal cancer patients (NCT02072720). Targeted protein inhibition and CRISPR/Cas-induced gene knockout was used to analyze the role of type I interferons and cGAS/STING signaling pathway in the molecular and cellular response to fractionated irradiation. Results: Gene expression analysis identified type I interferon signaling as the most significantly enriched biological process induced during fractionated irradiation. The commonality of this response was confirmed in all irradiated cell lines, the xenograft tumors and in biopsies from esophageal cancer patients. Time-course analyses demonstrated a peak in interferon-stimulated gene (ISG) expression within 2–3 weeks of treatment. The response was accompanied by a variable induction of predominantly interferon-beta and/or -lambda, but blocking these interferons did not affect ISG expression induction. The same was true for targeted inhibition of the upstream regulatory STING protein while knockout of STING expression only delayed the ISG expression induction. Conclusions: Collectively, the presented data show that clinically applied fractionated low-dose irradiation can induce a delayed type I interferon response that occurs independently of interferon expression or STING signaling. These findings have implications for current efforts that aim to target the type I interferon response for cancer treatment.
KW - Immune response
KW - Radiotherapy
KW - Type I interferons
UR - http://www.scopus.com/inward/record.url?scp=85105562873&partnerID=8YFLogxK
U2 - https://doi.org/10.1186/s13046-021-01962-2
DO - https://doi.org/10.1186/s13046-021-01962-2
M3 - Article
C2 - 33964942
SN - 1756-9966
VL - 40
JO - Journal of experimental & clinical cancer research
JF - Journal of experimental & clinical cancer research
IS - 1
M1 - 161
ER -