3,6-Dihydroxyflavone regulates microRNA-34a through DNA methylation

BMC Cancer

Research Article

Xiaoli Peng¹  Hui Chang²  Mantian Mi²  Qianyong Zhang²  Junli Chen²  Xiaoping Yu³ 

[1] Department of Public Health, School of Preclinical Medicine, Chengdu Medical College, Chengdu, China;Research Center for Nutrition Correspondence and Food Safety, Third Military Medical University, Chongqing Key Laboratory of Nutrition and Food Safety, 30 Gaotanyan Street, Shapingba District, 400038, Chongqing, China;Research Center for Nutrition Correspondence and Food Safety, Third Military Medical University, Chongqing Key Laboratory of Nutrition and Food Safety, 30 Gaotanyan Street, Shapingba District, 400038, Chongqing, China;Department of Public Health, School of Preclinical Medicine, Chengdu Medical College, Chengdu, China;

关键词: Breast cancer;    Carcinogenesis;    3,6-Dihydroxyflavone;    TET1;    DNMT1;    miR-34a;    Methylation;   

DOI  :  10.1186/s12885-017-3638-1

 received in 2016-01-21, accepted in 2017-08-29,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundBreast cancer is the common cancer in China. In previous study, we determined that 3,6-dihydroxyflavone (3,6-DHF) increases miR-34a significantly in breast carcinogenesis, but the mechanism remains unclear.MethodsWe used qRT-PCR to analyze miR-34a and ten-eleven translocation (TET)1, TET2, TET3 levels in breast cancer cells. With a cellular breast carcinogenesis model and an experimental model of carcinogenesis in rats, TET1 levels were evaluated by western blot analysis and immunofluorescence. TET1 and 5hmC (5-hydroxymethylcytosine) levels were evaluated by immunofluorescence in nude mouse xenografts of MDA-MB-231 cells. Chromatin immunoprecipitation(ChIP) assayed for TET1 on the TET1 promoter, and dot blot analysis of DNA 5hmC was performed in MDA-MB-231 cells. We evaluated the mechanism of 3,6-DHF on the expression of tumor suppressor miR-34a by transfecting them with DNA methyltransferase (DNMT)1 plasmid and TET1 siRNA in breast cancer cells. Methylation-specific PCR detected methylation of the miR-34a promoter.ResultsFirst, we found that 3,6-DHF promotes the expression of TET1 during carcinogen-induced breast carcinogenesis in MCF10A cells and in rats. 3,6-DHF also increased TET1 and 5hmC levels in MDA-MB-231 cells. Further study indicated that TET1 siRNA and pcDNA3/Myc-DNMT1 inhibited the 3,6-DHF reactivation effect on expression of miR-34a in breast cancer cells. Methylation-specific PCR assays indicated that TET1 siRNA and pcDNA3/Myc-DNMT1 inhibit the effect of 3,6-DHF on the demethylation of the miR-34a promoter.ConclusionsOur study showed that 3,6-DHF effectively increases TET1 expression by inhibiting DNMT1 and DNA hypermethylation, and consequently up-regulates miR-34a in breast carcinogenesis.

【 授权许可】

CC BY   
© The Author(s). 2017