title: Testosterone regulation of proto-oncogene c-myc expression in primary Sertoli cell cultures from prepubertal rats.
abstract: The expression of c-myc has been associated with cell proliferation through changes of nuclear function. To evaluate the possibility that the proto-oncogene c-myc plays a role in testosterone-dependent gene regulation, the effects of testosterone on the expression of c-myc have been investigated in primary Sertoli cell cultures. Testosterone increased c-myc mRNA levels, with maximal stimulation reached in 16 hours. The induction of c-myc mRNA was dependent on the concentration of testosterone. Testosterone-induced c-myc mRNA levels were also increased in cells after addition of cycloheximide but reduced by actinomycin-D pretreatment. Even in the absence of hormone in culture medium, c-myc mRNA was clearly detectable in Sertoli cells from 8-day-old rats but hardly detectable in cells from 14 and 28 days of age. Testosterone stimulated c-myc mRNA expression in the Sertoli cells from only 8-/and 14-day-old rats. These results suggest that testosterone induces c-myc mRNA levels in the primary Sertoli cells from prepubertal rats, and then transient expression of c-myc may be responsible for some of the regulatory roles of testosterone-dependent genes in the Sertoli cells. The biological significance of testosterone-dependent c-myc induction is not known.
authors.affiliation: Department of Biochemistry, School of Medicine, Chungnam National University, Daejeon, Korea.
authors.forename: K
authors.initials: K
authors.lastname: Lim
authors.forename: J H
authors.initials: JH
authors.lastname: Yoo
authors.forename: K Y
authors.initials: KY
authors.lastname: Kim
authors.forename: G R
authors.initials: GR
authors.lastname: Kweon
authors.forename: S T
authors.initials: ST
authors.lastname: Kwak
authors.forename: B D
authors.initials: BD
authors.lastname: Hwang
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D018507:Gene Expression Regulation, Developmental; D016259:Genes, myc / Q000187:drug effects / Q000502:physiology; D008297:Male; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D012708:Sertoli Cells / Q000166:cytology / Q000378:metabolism*; D012741:Sexual Maturation; D013739:Testosterone / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D003609:Dactinomycin; D013739:Testosterone; D003513:Cycloheximide