Identification of cellular responses to low-dose radiation by the profiling of phosphorylated proteins in human B-lymphoblast IM-9 cells

Abstract

Purpose: The aim of this study was to explore the potential for radiation-specific signaling of various LDIR-induced effects in human B-lymphoblast IM-9 cells.

Materials and methods: Human lymphoblast IM-9 cells were exposed to ionizing radiation at 0.1 and 2 Gy using a ¹³⁷Cs γ-irradiator at a dose rate of 0.8 Gy/min. Cell viability and DNA fragmentation were determined using MTT assay and TUNEL assay at 24 h after irradiation. Profiling of protein phosphorylation by radiation was identified using a phospho-antibody array at 4 h after irradiation and Dataset of the profiling was analyzed by IPA.

Results: Cell survival and apoptotic signaling were not affected by 0.1 Gy of radiation, whereas 2 Gy induced cellular damage. The analysis of low-dose ionizing radiation (LDIR) or high-dose ionizing radiation (HDIR)-specific responses by IPA generated different results. Various cell maintenance functions were only apparent following the analysis of increased protein phosphorylation by LDIR, whereas several cancer formation- and development-related functions were only detected following the analysis of increased protein phosphorylation by HDIR.

Conclusions: The LDIR-induced protein phosphorylation patterns might be involved in various cell survival responses or cellular maintenance functions, which provide important insight into our understanding of the different effects of LDIR and HDIR.

Keywords:

• Low-dose radiation
• phospho-antibody array
• immune

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Notes on contributors

Hyeon Soo Eom completed his PhD in Radiation Biotechnology Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute and Department of Biochemistry, College of Natural Sciences, Chungnam National University. He is a post-doctoral position in Low-Dose Radiation Research Team, KHNP-Radiation Health Institute (RHI).

Hyung Sun Park, MSc, is a researcher in Anaesthesiology and Pain Medicine, College of Medicine, Korea University, Seoul, Korea. She was a previous researcher in Low-dose Radiation Research Team, KHNP-RHI.

Gaeun You obtained her master degree in School of Biotechnology and Institute of Life Science and Resources, Kyung Hee University and is a researcher in Low-Dose Radiation Research Team, KHNP-RHI.

Ji Young Kim completed her PhD and followed by a research professor in school of Medicine, Sungkyunkwan University, Korea and currently, a principal researcher in Low-Dose Radiation Research Team, KHNP-RHI.

Seon Young Nam, PhD in Pharmacology, leads the Low-Dose Radiation Research Team at KHNP-RHI. Her main research interests are the understanding of biological effect of low-dose ionizing radiation (LDIR) and the development of LDIR-specific biomarkers.

Additional information

Funding

This work was supported by Grant no. 20131610101840 from the Ministry of Trade, Industry & Energy (MOTIE), Republic of Korea.