Estimation of low-dose radiation-responsive proteins in the absence of genomic instability in normal human fibroblast cells

Abstract

Purpose: Low-dose radiation has various biological effects such as adaptive responses, low-dose hypersensitivity, as well as beneficial effects. However, little is known about the particular proteins involved in these effects. Here, we sought to identify low-dose radiation-responsive phosphoproteins in normal fibroblast cells.

Materials and methods: We assessed genomic instability and proliferation of fibroblast cells after γ-irradiation by γ-H2AX foci and micronucleus formation analyses and BrdU incorporation assay, respectively. We screened fibroblast cells 8 h after low-dose (0.05 Gy) γ-irradiation using Phospho Explorer Antibody Microarray and validated two differentially expressed phosphoproteins using Western blotting.

Results: Cell proliferation proceeded normally in the absence of genomic instability after low-dose γ-irradiation. Phospho antibody microarray analysis and Western blotting revealed increased expression of two phosphoproteins, phospho-NFκB (Ser536) and phospho-P70S6K (Ser418), 8 h after low-dose radiation.

Conclusions: Our findings suggest that low-dose radiation of normal fibroblast cells activates the expression of phospho-NFκB (Ser536) and phospho-P70S6K (Ser418) in the absence of genomic instability. Therefore, these proteins may be involved in DNA damage repair processes.

Keywords:

• Low-dose radiation-responsive proteins
• phospho-NFκB (Ser536)
• phospho-P70S6K (Ser418)
• normal fibroblast cells
• genomic instability

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

Ji-Hye Yim is a post-doctoral research fellow at the Department of Low-Dose Radiation Research Team at KHNP Radiation Health Institute.

Jung Mi Yun is a postgraduate researcher at the Department of Low-Dose Radiation Research Team at KHNP Radiation Health Institute.

Ji Young Kim is a General manager at the Department of Low-Dose Radiation Research Team at KHNP Radiation Health Institute.

Seon Young Nam is a team manager at the Department of Low-Dose Radiation Research Team at KHNP Radiation Health Institute.

Cha Soon Kim is a senior researcher at the Department of Radiation Epidemiology Team at KHNP Radiation Health Institute.

Additional information

Funding

This work was supported by the Ministry of Trade, Industry & Energy, Republic of Korea [grant number 20131610101840].