FIGURE 4.

GRHL2 knockdown reduces cell proliferation, hTERT mRNA expression, and telomerase activity. A, rapidly proliferating NHEK and SCC15 cells were infected with LV-EGFP or LV-GRHL2i. Shown in the panel are the phase contrast and fluorescence images of the cells at 72 h after infection to demonstrate the efficiency of infection. Original magnification, ×100. B, NHEK, SCC15, and NHOK/Bmi-1 cells were infected with LV-EGFP or LV-GRHL2i and harvested after 72 h post-infection. Semi-quantitative RT-PCR was performed to determine the level of GRHL2, PCNA, and hTERT mRNA with or without GRHL2 knockdown. GRHL2 knockdown in SCC4 cells was accomplished in our previous report (10). GAPDH was amplified as a loading control. C, effects of GRHL2 knockdown on cell proliferation were determined in NHEK, NHOK/Bmi-1, and SCC15 cells by counting the cells after 72 h post-infection. D, organotypic raft cultures were established with NHEK and SCC15 infected with LV-EGFP or LV-GRHL2i. After 14 days of culture, the reconstructs were harvested for histological examination in sagittal orientation.