Figure 7.

Inhibition of c-jun, c-fos, and MMP-1 mRNA by PD98059. Semiconfluent PECs were exposed to 20 mJ/cm² UVB. Total RNA was isolated at intermediate (2 to 6 hours) and at a late (24 hours) time point after UVB and analyzed by RT-PCR to determine c-fos (A), c-jun (B), MMP-1 (C), and GAPDH (D) mRNA expression using gene-specific primers. Control reactions included RNA that was not reverse transcribed (−RT) or reactions in which the primer pairs were omitted (−1°). Molecular weight of the products was estimated by comparison to a 100-bp ladder. These results were semiquantified and graphically represented as fold-induction for c-jun (E), c-fos (F), and MMP-1 (G) that was standardized to GAPDH levels (D).