Melanoma differentiation-associated gene-7, MDA-7/IL-24, selectively induces growth suppression, apoptosis in human hepatocellular carcinoma cell line HepG2 by replication-incompetent adenovirus vector

Figure 3 Over-expression of mda-7 causes apoptosis selectively in HCC cells (400×). Cells were infected with 1 000 VP/cell of Ad.mda-7 and all assays were performed 48 h after infection as described in ‘Materials and Methods’. To evaluate characteristic apoptotic morphology with fluorescence microscopy, the cells were seeded on glass slides and fixed with 40 g/L paraformaldehyde in PBS for 1 h at room temperature. After washing twice with PBS, cells were stained for 30 min in the dark at room temperature with 0.05 mg/mL Hoechst 33258 in PBS. The nuclear fragmentations were visualized by using a fluorescence microscope equipped with a UV-2A filter and Olympus BX60 photographic camera. Apoptotic cells were recognized by condensation of nuclear chromatin and its fragmentation.