Effect of different dose rates of ionizing radiation on ciliogenesis in hTERT-RPE1 cells

Abstract

Ionizing radiation (IR) induces genome instability and chromosome aberration in mammalian cells. IR exposure generates DNA damage, which is repaired by several DNA repair pathways. Meanwhile, IR also induces ciliogenesis and centrosome overduplication associated with cell cycle checkpoint mechanism. Centrosome number is strictly regulated, since overduplicated centrosomes cause aneuploidy, leading to tumorigenesis. Primary cilia play a sensory role in several signaling pathways during development and cellular homeostasis. In this study, to address how IR affects ciliogenesis, we irradiated telomerase reverse transcriptase-immortalized retina pigmentation epithelial cell, hTERT-RPE1, with γ-ray at different dose rates, that is 2 mGy/s (low dose rate) and 100 mGy/s (high dose rate). Centrosome and primary cilia were detected by immunofluorescence using γ-tubulin and acetylated-α-tubulin antibodies, respectively. After IR exposure, we saw an increase in cells with primary cilia and the combined treatment of IR exposure with serum starvation stimulation showed an additive effect. This study provides a new insight into radiation effect on the extracellular response.