title: Fractionated radiation alters oncomir and tumor suppressor miRNAs in human prostate cancer cells.
abstract: We have previously demonstrated that prostate carcinoma cells exposed to fractionated radiation differentially expressed more genes compared to single-dose radiation. To understand the role of miRNA in regulation of radiation-induced gene expression, we analyzed miRNA expression in LNCaP, PC3 and DU145 prostate cancer cells treated with single-dose radiation and fractionated radiation by microarray. Selected miRNAs were studied in RWPE-1 normal prostate epithelial cells by RT-PCR. Fractionated radiation significantly altered more miRNAs as compared to single-dose radiation. Downregulation of oncomiR-17-92 cluster was observed only in the p53 positive LNCaP and RWPE-1 cells treated with single-dose radiation and fractionated radiation. Comparison of miRNA and mRNA data by IPA target filter analysis revealed an inverse correlation between miR-17-92 cluster and several targets including TP53INP1 in p53 signaling pathway. The base level expressions of these miRNAs were significantly different among the cell lines and did not predict the radiation outcome. Tumor suppressor miR-34a and let-7 miRNAs were upregulated by fractionated radiation in radiosensitive LNCaP (p53 positive) and PC3 (p53-null) cells indicating that radiation-induced miRNA expression may not be regulated by p53 alone. Our data support the potential for using fractionated radiation to induce molecular targets and radiation-induced miRNAs may have a significant role in predicting radiosensitivity.
authors: Radiation Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA. aryankalayilm@mail.nih.gov
authors: Molykutty
authors: M
authors: John-Aryankalayil
authors: Sanjeewani T
authors: ST
authors: Palayoor
authors: Adeola Y
authors: AY
authors: Makinde
authors: David
authors: D
authors: Cerna
authors: Charles B
authors: CB
authors: Simone
authors: Michael T
authors: MT
authors: Falduto
authors: Scott R
authors: SR
authors: Magnuson
authors: C Norman
authors: CN
authors: Coleman
mesh_terms: D045744:Cell Line, Tumor; D019583:Dose Fractionation, Radiation; D004847:Epithelial Cells / Q000378:metabolism / Q000528:radiation effects; D006358:Hot Temperature; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics / Q000528:radiation effects; D008297:Male; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000473:pathology*; D011836:Radiation Tolerance / Q000235:genetics / Q000528:radiation effects; D015203:Reproducibility of Results; D059467:Transcriptome / Q000528:radiation effects
chemical_list: D035683:MicroRNAs