Identification of ionizing radiation-responsive microRNAs in the IM9 human B lymphoblastic cell line.
Ionizing radiation (IR) disrupts cellular homeostasis through multiple mechanisms including changes of the expression profile of genes. Although microRNAs (miRNAs), small single-stranded RNAs, have recently been recognized as important post-transcriptional regulators of gene expression, it is not well investigated if miRNAs function in the cellular response to radiation. Therefore, we determined if IR induces changes in the expression profiles of miRNAs and used this approach to identify IR-responsive miRNAs. To monitor the profiles of miRNAs, microarray analysis was conducted with irradiated IM9 human lymphoblastic cells. The expression levels of specific miRNAs were confirmed by quantitative real-time PCR (qRT-PCR) and statistically analyzed. Finally, the target mRNAs of some IR-responsive miRNAs were predicted with two different prediction programs. IR-exposed human lymphoblastic cells underwent cell cycle arrest and apoptosis. Apoptosis was more significantly increased at a higher radiation dose. There were 73 and 33 human miRNAs in 1 and 10 Gy-irradiated cells, respectively that showed expression level changes of >2-fold. By qRT-PCR analysis, it was revealed that the patterns of miRNA expression were similar to those observed in the microarray data, although the quantitative expression levels were discordant. Prediction of genes targeted by IR-responsive miRNA yielded several genes, many of which are involved in the regulation of apoptosis, the cell cycle, and DNA repair. The expression profiles of miRNAs in the IM9 human B lymphoblastic cells are strongly affected by IR and these changes may be involved in the regulation of cellular response to IR.
Cha
Hwa Jun
HJ
Functional Genoproteome Research Centre, Konkuk University, Seoul 143-701, Korea.
Shin
Sangsu
S
Yoo
Hoesook
H
Lee
Eun-Mee
EM
Bae
Seunghee
S
Yang
Kwang-Hee
KH
Lee
Su-Jae
SJ
Park
In-Chul
IC
Jin
Young-Woo
YW
An
Sungkwan
S
D019295:Computational Biology; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000528:radiation effects*; D006801:Humans; D008214:Lymphocytes / Q000528:radiation effects*; D008223:Lymphoma / Q000235:genetics*; D035683:MicroRNAs / Q000502:physiology* / Q000528:radiation effects*; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011839:Radiation, Ionizing; D020133:Reverse Transcriptase Polymerase Chain Reaction
D035683:MicroRNAs; D012333:RNA, Messenger