title: The inhibitory effect of aryl hydrocarbon receptor repressor (AhRR) on the growth of human breast cancer MCF-7 cells.
abstract: The variant cell lines stably expressing aryl hydrocarbon receptor repressor (AhRR), MCFRR1 and MCFRR4, were established from human breast cancer MCF-7 cells by transfecting with AhRR-expression construct followed by selection, in order to analyze the effect of AhRR on the cell growth and expression of cell cycle-related genes. The variant cells showed higher levels of AhRR mRNA compared with the parental cells. MCFRR4 cells grew slowly compared with MCF-7 in both cell number and proliferation rate measured by the MTS method. Among cell cycle-related genes such as E2F, cyclin E1, cyclin D1, PCNA, p53, Rb, c-myc and p27Kip1, and estrogen responsive genes such as cathepsin D and hsp27, the expression levels of E2F, cyclin E1, PCNA and cathepsin D mRNA in MCFRR4 cells were lower than those in MCF-7 cells, while those of Rb, p27Kip1, c-myc and hsp27 mRNA were not significantly affected and that of cyclin D1 mRNA was enhanced in variant cells. Based on these results, AhRR might be suppressive on cell growth of MCF-7 by disturbing the transcriptional and/or posttranscriptional regulations of estrogen-responsive and cell cycle-related genes.
authors.affiliation: Faculty of Pharmaceutical Sciences, Toho University, Funabashi, Chiba, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Kanno
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Takane
authors.forename: Tomomi
authors.initials: T
authors.lastname: Izawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakahama
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Inouye
mesh_terms: D051792:Basic Helix-Loop-Helix Proteins; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D018929:Cell Culture Techniques; D002453:Cell Cycle / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005260:Female; D006801:Humans; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism / Q000502:physiology*; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D018336:Receptors, Aryl Hydrocarbon; D012097:Repressor Proteins; C492161:Ahrr protein, rat