Down regulation of c-myc, c-fos and erb-B during estrogen induced proliferation of the chick oviduct.
Oncogenes c-myc, H-ras, c-fos and erb-B were constitutively expressed in immature chick oviduct withdrawn from estrogen administration for 2.5 weeks after 10 d of primary estrogen stimulation. Following secondary estrogen stimulation of the withdrawn chicks, synthesis of egg white proteins is rapidly induced and remaining non-functioning tubular gland cells are stimulated to proliferate with a doubling time of 24 h. During first 12 h of secondary estrogen stimulation, H-ras mRNA levels doubled and did not increase further at 24 h and 48 h. The steady state levels of c-myc, erb-B and c-fos mRNA decreased 24 h following secondary estrogen stimulation. The levels of these oncogene RNAs in oviduct were similar at 48 h following secondary estrogen stimulation to those from immature chicks administered 10 d of primary estrogen stimulation. Thus elevated expression of c-myc and c-fos mRNA does not appear to be necessary components for sustained estrogen induced cell proliferation in the chick oviduct.
Cohrs
R J
RJ
Department of Molecular Biology, AMC Cancer Research Center, Denver, Colorado 80214.
Goswami
B B
BB
Sharma
O K
OK
D000199:Actins / Q000235:genetics; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002645:Chickens; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D005786:Gene Expression Regulation; D007700:Kinetics; D009857:Oncogenes; D009929:Organ Size / Q000187:drug effects; D010047:Ovalbumin / Q000235:genetics; D010057:Oviducts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D014158:Transcription, Genetic
D000199:Actins; D012333:RNA, Messenger; D004958:Estradiol; D010047:Ovalbumin