ANALYSIS OF POLYPEPTIDE CHANGES DURING CELLULAR DIFFERENTIATION

点击翻译按钮获取中文摘要

This project was initiated to analyze, both qualitatively and quantitatively, changes in total cellular protein patterns during cellular differentiation and transformation using the technique of quantitative two-dimensional electrophoresis. A cell culture system has been developed for the study of differentiation of primary normal human bronchial epithelial (NHBE) cells by 12-0-tetradecanoyl-13-acetate (TPA) or transforming growth factor type beta (TGF-beta). Two-dimensional gel electrophoresis (2D-PAGE) of [14-C]-labeled polypeptides following treatment of NHBE cells and the human lung carcinoma cell line, A1146, with TPA and TGF-beta resulted in only quantitative polypeptide differences. NHBE cells showed a more pronounced modulation of polypeptide expression following treatment with TPA (10 nM) and TGF-beta (30 pg/ml) than A1146 cells, a cell line refractory to differentiation induction by TPA and TGF-beta. After 24 hr treatment of NHBE cells with TPA and TGF-beta, 15 polypeptides were specifically modulated by TPA, 4 were modulated by TGF-beta alone, and 6 were affected by both TPA and TGF-beta. Prolonged exposure (72 hr) resulted in predominantly (38/42) TPA-induced changes and only one polypeptide was specifically modulated by TGF-beta. Of the 42 polypeptides significantly modulated at 72 hr, 4 polypeptides (5.85/88 kDa; 6.10/40 kDa; 5.00/40 kDa; and 5.80/28 kDa) also exhibited significant quantitative modulation after 24 hr treatment.