FIG. 3.
Active MKK3 and MKK6 up-regulate 16INK4A mRNA levels. Total RNA was isolated from BJ cells 8 days after being transduced with a vector control (BP) or retroviruses encoding active MKK3 (MKK3E) or MKK6 (MKK6E). Eight micrograms of RNA was separated on an agarose gel, transferred to nylon membrane, and hybridized to a p16INK4A cDNA probe labeled by random priming. The signals were visualized and quantitated with a phosphorimager. The numbers represent the relative intensities of p16INK4A signals after normalization to those of background and GAPDH signals (data not shown).