EGF-dependent mouse epithelial mammary HC11 cell line demonstrates high extent of cell cycle synchronization upon stimulation by epidermal growth factor

摘要

The most popular object foe studying endocytosis Of EGF-receptor complexes, human epidermoid carcinoma A431, was shown to answer to EGF in high concentration (100 ng/ml) by growth inhibition, being indifferent to lower (0.1--1 ng/ml) concentrations. At the same time, cells NIH 3T3, expressing human EGF receptor (HER14), and epithelial mammary cells Hell increased ~(14)C-thymidine incorporation into DNA after EGF addition. However, for HERI4 cells stimulatory effect of EGF was twice weaker than that induced by serum, whereas the effect of EGF on ~(14)C-thymidine incorporation in DNA of cells HC11 was approximately 5 times stronger compared to serum. Therefore, cells Hell maybe referred to as EGF-dependent. Cell cycle analysis by fluorimetry showed that more than 90 % of serum-starved HERl4 and HC11 were in G0/G1. Within 19--20 h after stimulation by EGF 70.90 % of HC11 cells and only 30-40 % of HER14 cells were in S-phase. EGF removing from culture medium earlier than 9--11 h after stimulation blocked entering of Hell cells into S-phase, whereas .such EGF-dependent period was not found for cells HER14. Thus, synchronization of progression through early stages of cell cycle, stimulated by EGF and the presence of well defined 《early》(EGF-dependent and ,