Expression pattern of small nucleolar RNA host genes and long non-coding RNA in X-rays-treated lymphoblastoid cells

Abstract

A wide variety of biological effects are induced in cells that are exposed to ionizing radiation. The expression changes of coding mRNA and non-coding micro-RNA have been implicated in irradiated cells. The involvement of other classes of non-coding RNAs (ncRNA), such as small nucleolar RNAs (snoRNAs), long ncRNAs (lncRNAs), and PIWI-interacting RNAs (piRNAs) in cells recovering from radiation-induced damage has not been examined. Thus, we investigated whether these ncRNA were undergoing changes in cells exposed to ionizing radiation. The modulation of ncRNAs expression was determined in human TK6 (p53 positive) and WTK1 (p53 negative) cells. The snoRNA host genes SNHG1, SNHG6, and SNHG11 were induced in TK6 cells. In WTK1 cells, SNHG1 was induced but SNHG6, and SNHG11 were repressed. SNHG7 was repressed in TK6 cells and was upregulated in WTK1 cells. The lncRNA MALAT1 and SOX2OT were induced in both TK6 and WTK1 cells and SRA1 was induced in TK6 cells only. Interestingly, the MIAT and PIWIL1 were not expressed in TK6 cells before or after the ionizing radiation treatment. The MIAT and PIWIL1 were upregulated in WTK1 cells. This data provides evidence that altered ncRNA expression is a part of the complex stress response operating in radiation-treated cells and this response depends on functional p53.

Figure 1

Modulation of various small nucleolar RNA host genes in 2 Gy irradiated TK6 and WTK1 cells. The relative expression, shown as Log₂ values, was computed at 0.5 h, 4 h, 8 h, 12 h, and 24 h time points. (A) SNHG1; (B) SNHG5; (C) SNHG6; (D) SNHG7; (E) SNHG8; (F) SNHG11. (◆) TK6 cells, (■) WTK1 cells. The error bars indicate the standard error of the mean (SEM) for three independent experiments.

Figure 2

Expression analysis of non-coding RNA genes in 2 Gy irradiated TK6 and WTK1 cells. The data is plotted as Log2 values and indicate relative expression measured at 0.5 h, 4 h, 8 h, 12 h, and 24 h time points after radiation treatment. (A) MALAT1; (B) MATR3; (C) SRA1; (D) SOX2OT; (E) MIAT; (F) PIWIL1. (◆) TK6 cells, (■) WTK1 cells. The error bars indicate the standard error of the mean (SEM) for three independent experiments.