title: CTCFandCTCFLmRNA expression in 17β-estradiol-treated MCF7 cells.
abstract: Estrogens play a key role in breast cancer, with 60-70% of the cases expressing estrogen receptors (ERs), which are encoded by theESR1gene. CTCFL, a paralogue of the chromatin organizer CTCF, is a potential biomarker of breast cancer, but its expression in this disease is currently controversial. A positive correlation has been reported between CTCFL and ERs in breast tumors and there also exists a coordinated interaction between CTCF and ERs in breast cancer cells. Therefore, there appears to be an association between CTCF, CTCFL and estrogens in breast cancer; however, there has been no report on the effects of estrogens onCTCFandCTCFLexpression. The aim of this study was to determine the effect of 17β-estradiol (E2) on theCTCFandCTCFLmRNA expression in the MCF7 breast cancer cell line. The promoter methylation status ofCTCFLand data mining for estrogen response elements in promoters of theCTCFandCTCFLgenes were also determined. The transcription ofCTCFandCTCFLwas performed by quantitative polymerase chain reaction (qPCR) and the promoter methylation status ofCTCFLwas determined by methylation-specific PCR. The MCF7 cells exhibited basal transcription ofCTCF, which was significantly downregulated to 0.68 by 1 μM E2; basal or E2-regulated transcription ofCTCFLwas not detected. Under basal conditions, theCTCFLpromoter was methylated. Through data mining, an estrogen response element was identified in theCTCFpromoter, but no such element was found inCTCFL. These results suggested that estrogens may modulateCTCFexpression, although there was no apparent association between ERs andCTCFL.
authors.affiliation: Department of Molecular Medicine, Faculty of Medicine and Nutrition, Juárez University of the State of Durango, Durango 34000, Mexico.
authors.forename: Eduardo Portillo
authors.initials: EP
authors.lastname: Del Campo
authors.affiliation: Department of Molecular Medicine, Faculty of Medicine and Nutrition, Juárez University of the State of Durango, Durango 34000, Mexico ; Department of Biochemistry, Faculty of Medicine and Nutrition, Juárez University of the State of Durango, Durango 34000, Mexico.
authors.forename: José Jorge Talamás
authors.initials: JJ
authors.lastname: Márquez
authors.affiliation: Cancer State Center of the Ministry of Health, Durango, Durango 34000, Mexico.
authors.forename: Francianella
authors.initials: F
authors.lastname: Reyes-Vargas
authors.affiliation: Department of Biochemistry, Faculty of Medicine and Nutrition, Juárez University of the State of Durango, Durango 34000, Mexico.
authors.forename: María Del Pilar
authors.initials: MD
authors.lastname: Intriago-Ortega
authors.affiliation: Department of Biochemistry, Faculty of Medicine and Nutrition, Juárez University of the State of Durango, Durango 34000, Mexico.
authors.forename: Martha Angélica
authors.initials: MA
authors.lastname: Quintanar-Escorza
authors.affiliation: Department of Biochemistry, Faculty of Medicine and Nutrition, Juárez University of the State of Durango, Durango 34000, Mexico.
authors.forename: Jorge Alberto
authors.initials: JA
authors.lastname: Burciaga-Nava
authors.affiliation: Department of Biochemistry, Faculty of Medicine and Nutrition, Juárez University of the State of Durango, Durango 34000, Mexico.
authors.forename: Antonio
authors.initials: A
authors.lastname: Sifuentes-Alvarez
authors.affiliation: Department of Molecular Medicine, Faculty of Medicine and Nutrition, Juárez University of the State of Durango, Durango 34000, Mexico.
authors.forename: Miguel
authors.initials: M
authors.lastname: Reyes-Romero
keywords: CTCF; CTCFL; MCF7 cells; estrogens; gene expression