Baliga B S, Borowitz S M, Barnard J A
Department of Pediatrics, University of South Alabama College of Medicine, Mobile 36617.
Biochem Int. 1989 Nov;19(5):1045-56.
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.
用表皮生长因子（EGF）诱导源自大鼠空肠隐窝的上皮细胞系（IEC-6）增殖。EGF以剂量依赖的方式增强蛋白质、RNA和DNA的合成。蛋白质合成在暴露于EGF的6至12小时内增加，并在72小时内保持升高。添加EGF后48小时出现最大的3H-胸苷掺入。在无血清培养基中，EGF对3H-胸苷掺入的刺激作用比含有胎牛血清（FCS）的培养基中高两倍。与EGF相反，佛波醇-12-肉豆蔻酸酯-13-乙酸酯（PMA）降低了IEC-6细胞对3H-胸苷的摄取，并且对蛋白质合成或RNA合成均无影响。EGF不会改变IEC-6细胞中的蛋白激酶C活性，而PMA会诱导酶活性：活性从细胞质转移到细胞膜。此外，阿米洛利不会改变与EGF相关的3H-胸苷摄取增加。这些数据表明蛋白激酶C激活可能不参与IEC-6细胞的增殖。
