Objective: The relationship between basic fibroblast growth factor (bFGF) and phosphatidylinositol 3-kinase/protein kinase B(PI 3-K/PKB) signal pathway was studied during the course of bFGF regulating carcinoma epithelioid cell lines- I (CNE- I ) nasopharyngeal carcinoma cell proliferation through altering time of bFGF treatment.
Methods: PKB activities were measured by advanced Takai method. C-fos expression was examined by Western Blot.
Results: bFGF (50 ng/ml) significantly stimulated PKB activity,After pretreatment of Wortmannin for 1 h, the PKB activity decreases to the basal levels(P < 0. 05),compared with control group. After treatment of bFGF (50 ng/ml) at various time, the expression of c-fos is increased. The expression of c-fos increases to the peak when the time of bFGF treatment is 30 min. After pretreatment of Wortmannin for 1 h, the expression of c-fos decreases 20% when the time of bFGF treatment was 30 min and when the time of bFGF treatment was 45 min, the expression of c-fos decreases 35%.
Conclusions: 1. PI 3-K and PKB mediate bFGF-induced signal transduction in CNE- I nasopharyngeal carcinoma cell line; PKB lies in downstream of PI 3-K. 2. bFGF induces the increased expression of c-fos through PI 3-K/PKB in CNE- I nasopharyngeal carcinoma cell line.