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Expression of Micro-RNA-492 (MiR-492) in Human Cervical Cancer Cell Lines is Upregulated by Transfection with Wild-Type P53, Irradiation, and 5-Fluorouracil Treatment In Vitro

2018; International Scientific Information Inc.; Volume: 24; Linguagem: Inglês

10.12659/msm.911585

1643-3750

Mei Liu, Zaozao Wang, Qiao Liu, Hongxia Zhu, Ningzhi Xu,

Circular RNAs in diseases

BACKGROUND The status of p53 is critical to the chemoradiosensitivity of cervical cancer cells. Wild-type p53 is essential to orchestrate the cellular response to cytotoxic stimuli. Our previous data illustrated that cervical cancer patients whose specimens overexpressed microR-492 (miR-492) were highly sensitive to concurrent chemoradiation. Although p53 activation has been reported to upregulate miR-492 by a miRNA profiling assay in lung cancer cells, the transcriptional regulation of miR-492 in cervical cancer cells remains poorly understood. Therefore, we aimed to decipher the relationship between p53 and miR-492 in cervical cancer cells. MATERIAL AND METHODS The expression of p53 and miR-492 in cervical cancer cell lines was measured by western blot and real-time PCR. After cells were transfected with wild-type p53 plasmid or were treated by irradiation and 5-fluorouracil (5-FU), the expression changes of p53 as well as miR-492 were examined by western blot and real-time PCR. The putative p53 binding site of miR-492 was first analyzed by bioinformatics tools, then validated by chromatin immunoprecipitation and dual-luciferase reporter assays. RESULTS We found that miR-492 was upregulated in cells with wild-type p53 compared to cells with mutant p53. Transfection of wild-type p53 plasmid or treatments with cytotoxic reagents including irradiation and 5-FU all induced miR-492 overexpression. Bioinformatics analysis and experimental validations further proved p53 interacted with miR-492 promoter directly. CONCLUSIONS In cervical cancer cells, p53 activated miR-492 expression transcriptionally.