Cyclin A is required in S phase in normal epithelial cells.
We have investigated cyclin A expression in a primary culture of normal rat hepatocytes and during rat liver regeneration after partial hepatectomy. In both cases, cyclin A mRNA and protein accumulate as the cells enter S phase. To investigate the potential implication of cyclin A accumulation at S phase, we microinjected anti-sense DNA constructs for cyclin A, resulting in effective inhibition of S phase entry. These effects were specific for cyclin A since anti-sense cyclin B construct had no similar effects. These results therefore, obtained in normal epithelial cells, indicate that cyclin A is involved in S phase and thus should not be only considered as a mitotic cyclin.
Zindy
F
F
INSERM U75, C.H.U. Necker, Paris, France.
Lamas
E
E
Chenivesse
X
X
Sobczak
J
J
Wang
J
J
Fesquet
D
D
Henglein
B
B
Bréchot
C
C
D000818:Animals; D001345:Autoradiography; D015152:Blotting, Northern; D002478:Cells, Cultured; D016895:Culture Media, Serum-Free; D016213:Cyclins / Q000235:genetics / Q000502:physiology*; D004261:DNA Replication / Q000187:drug effects; D016373:DNA, Antisense / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D004847:Epithelial Cells; D004848:Epithelium / Q000502:physiology; D006498:Hepatectomy; D007150:Immunohistochemistry; D007328:Insulin / Q000494:pharmacology; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D008297:Male; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats; D011919:Rats, Inbred Strains; D016196:S Phase / Q000187:drug effects; D013936:Thymidine / Q000378:metabolism; D014316:Tritium
D016895:Culture Media, Serum-Free; D016213:Cyclins; D016373:DNA, Antisense; D007328:Insulin; D012333:RNA, Messenger; D014316:Tritium; D003907:Dexamethasone; D013936:Thymidine