Figure 5. Role of fibroblast SIRT1 in cancer cell colonization.

B16F10 A, D. SKOV3 B, E. or SNU840 C, F. cancer cells, which had been transfected with pcDNA or SIRT1 plasmid, were seeded on 0.4% top agar and cultured in the mixture (1:1) of fresh medium and conditioned medium from MEF-1 or CCD18Lu fibroblasts which had been transected with plasmids (empty vector or SIRT1) or siRNAs (non-targeting or SIRT1-targeting). On day 21 after cell seeding, cell colonies were visualized using crystal violet and counted. Data (number of colonies per 3.7 cm²) are presented as the mean + s.d. (n=4). *, p < 0.05. P, +S, N, and -S denote the transfection with pcDNA, SIRT1 plasmid, non-targeting RNA, and SIRT1-targeting siRNA, respectively.