Androgen regulation of c-myc messenger ribonucleic acid levels in rat ventral prostate.
Androgens regulate growth of the rat ventral prostate gland. In a search for possible mediators of androgen stimulated growth we have studied c-myc proto-oncogene expression in ventral prostate after androgen withdrawal and replacement. Steady state levels of c-myc mRNA were determined by Northern hybridization and compared with mRNA levels for prostatein, the major androgen dependent protein of ventral prostate. C-myc mRNA in ventral prostate increased nearly 4-fold within 1 day and 6- to 7-fold within 2 days after castration. Administration of androgen at the time of castration prevented this increase in c-myc mRNA levels. Androgen treatment of 4-day castrate rats caused c-myc mRNA levels to decrease within 4 h. Cycloheximide increased c-myc mRNA severalfold within 2 h. The net increase in c-myc mRNA after cycloheximide treatment was greater in the castrate than in the noncastrate or in androgen-treated castrate rats. These results suggest that androgen may influence both transcription and turnover of c-myc mRNA. Prostatein C3 mRNA decreased rapidly after castration and increased after androgen treatment of the castrate but was only slightly influenced by cycloheximide. Steady state levels of c-myc mRNA were higher in the 10-day-old rat and decreased with age while prostatein C3 mRNA increased with age. In situ hybridization demonstrated that both c-myc and prostatein mRNAs are expressed in the epithelial cells of ventral prostate acinar glands. These data indicate that androgens regulate the expression of c-myc in the ventral prostate.
Quarmby
V E
VE
Laboratory for Reproductive Biology, University of North Carolina Medical School Chapel Hill 27599.
Beckman
W C
WC
Wilson
E M
EM
French
F S
FS
D000375:Aging / Q000378:metabolism; D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D016259:Genes, myc; D008297:Male; D009693:Nucleic Acid Hybridization; D009919:Orchiectomy; D011467:Prostate / Q000187:drug effects / Q000378:metabolism*; D012313:RNA / Q000302:isolation & purification; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013739:Testosterone / Q000494:pharmacology*
D012333:RNA, Messenger; D013739:Testosterone; D012313:RNA; D003513:Cycloheximide