Ionizing radiation is widely used for patient with glioblastoma (GBM). However, the effect of radiation on patient survival is marginal and upon recurrence tumors frequently shift toward mesenchymal subtype adopting invasiveness. Here, we show that ionizing radiation affects biomechanical tension in GBM microenvironment and provides proinvasive extracellular signaling cue, hyaluronic acid (HA)-rich condition. In response to radiation, HA production was increased in GBM cells by HA synthase-2 (HAS2) that was transcriptionally upregulated by NF-KB. Notably, NF-KB was persistently activated by IL-1α-feedback loop, making HA abundance in tumor microenvironment after radiation. Radiation-induced HA abundance causally has been linked to invasiveness of GBM cells by generating movement track as an extracellular matrix, and by acting as a signaling ligand for CD44 receptor, leading to SRC activation, which is sufficient for mesenchymal shift of GBM cells. Collectively, our findings provide an explanation for the frequent brain tumor relapse after radiotherapy, and potential therapeutic targets to block mesenchymal shift upon relapse.
Bibliographical noteFunding Information:
Funding This work was supported by the National Research Foundation (NRF) and Ministry of Science, ICT and Future Planning, Korean Government, through its National Nuclear Technology Program (NRF-2015M2A2A7A01044998 and NRF-2016R1E1A1A01942075).
© 2018 Macmillan Publishers Limited, part of Springer Nature.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cancer Research