Microarray data analysis reveals gene expression changes in response to ionizing radiation in MCF7 human breast cancer cells.

Background: The aim of this study was to identify potential therapeutic target genes for breast cancer (BC) by the investigation of gene expression changes after ionizing radiation (IR) in BC cells. Gene expression profile GSE21748, including BC cell line MCF-7 samples at different time points after IR treatment, were downloaded from Gene Expression Omnibus. Differentially expressed genes (DEGs) were identified in different time points following IR compared with cell samples before IR, respectively. Gene ontology functions and The Kyoto Encyclopedia of Genes and Genomes pathways of the overlapping DEGs were enriched using DAVID. Transcription factor (TFs)-encoding genes were identified from the overlapping DEGs, followed by construction of transcriptional regulatory network and co-expression network.

Results: A total of 864 overlapping DEGs were identified, which were significantly enriched in regulation of cell proliferation and apoptosis, and cell cycle process. We found that FOXD1, STAT6, XBP1, STAT2, LMO2, TFAP4, STAT3, STAT1 were hub nodes in the transcriptional regulatory network of the overlapping DEGs. The co-expression network of target genes regulated by STAT3, STAT1, STAT6 and STAT2 included some key genes such as BCL2L1.

Conclusion: STAT1, STAT2, STAT3, STAT6, XBP1, BCL2L1, CYB5D2, ESCO2, and PARP2 were significantly affected by IR and they may be used as therapeutic gene targets in the treatment of BC.