FIG. 1.

Coexpression of HPV oncoproteins and H-rasV12 in primary HFKs. (A) Morphology and senescence induction of the HFKs expressing HPV oncoproteins and H-ras. The senescent cells were detected by SA-β-gal assay. The control cells (Cr) used in this and the following experiments were infected with two empty retroviral vectors, pLXSN and pLPCX. Magnification, ×200. (B) The effects of H-ras activation on the proliferation of the HFKs expressing HPV oncoproteins. At days 1 and 3 after they were seeded, the cells in the dishes were counted, and relative cell numbers (those at 1 day after seeding are set at 1) are indicated as a bar.