Effects of EGF and PMA on the growth and proliferation of IEC-6 cells.
Proliferation of an epithelial line (IEC-6) derived from the crypts of rat jejunum was induced with epidermal growth factor (EGF). EGF enhanced synthesis of protein, RNA, and DNA in a dose-dependent manner. Protein synthesis increased within 6-12 hours of exposure to EGF and remained elevated for 72 hours. Maximal 3H-thymidine incorporation occurred 48 hours after addition of EGF. The stimulatory effect of EGF on 3H-thymidine incorporation was two-fold greater in serum-free media than in media containing fetal calf serum (FCS). In contrast to EGF, phorbol-12-myristate-13-acetate (PMA) decreased 3H-thymidine uptake by IEC-6 cells and had no effect on either protein synthesis or RNA synthesis. EGF did not alter protein kinase-C activity in IEC-6 cells whereas PMA induced enzyme activity: activity was translocated from cytosol to membrane. Moreover, the EGF-associated increase in 3H-thymidine uptake was not altered by amiloride. These data suggest protein kinase-C activation may not be involved in the proliferation of IEC-6 cells.
Baliga
B S
BS
Department of Pediatrics, University of South Alabama College of Medicine, Mobile 36617.
Borowitz
S M
SM
Barnard
J A
JA
D000818:Animals; D002460:Cell Line; D004247:DNA / Q000096:biosynthesis; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D004848:Epithelium; D007421:Intestine, Small / Q000166:cytology / Q000378:metabolism; D014176:Protein Biosynthesis; D012313:RNA / Q000096:biosynthesis; D051381:Rats; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013997:Time Factors
D004815:Epidermal Growth Factor; D012313:RNA; D004247:DNA; D013755:Tetradecanoylphorbol Acetate