FIG. 1.

uPA induction by UV irradiation. (A) Analysis of uPA mRNA expression in UV-stimulated NIH 3T3 fibroblast cells. NIH 3T3 cells were cultured in 0.5% FBS for 16 h and then irradiated with UVC or treated with TPA. Total RNA was extracted at the indicated time points after UVC and TPA stimulation and analyzed by Northern blotting with the mouse uPA and GAPDH cDNA probes as indicated. (B) Analysis of uPA mRNA expression in UV-stimulated F9 teratocarcinoma cells. F9 cells were cultured in 0.5% FBS for 16 h and then exposed to UVC or TPA. Poly(A)⁺ mRNA was extracted at the indicated time points and analyzed by Northern blotting as for panel A.