Figure 1. Low dose mitochondrial photodynamic treatment enhanced HeLa cell proliferation.

(A) Kinetic measurements of PpIX accumulation in HeLa cells following ALA-induction. HeLa cells were incubated with 200 μM ALA for up to 12 h. Open symbols represent experiments with ALA, closed symbols represent experiments with ALA supplemented with CCCP (10 μM) at 4 h and removal of CCCP at 8 h. (B) Cell viability was measured by MTT assay 24 h in HeLa cells incubated with 10-1000 μM ALA. (C) Cell viability was measured by MTT assay 24 h after laser irradiation in HeLa cells incubated with 200 μM ALA (D) Cell growth was monitored by RT-CES System. Laser irradiation was applied at 24 h and 48 h time points. (E) FACS analysis to classify each cell cycle. Quantification of every phase by PI staining was performed. The percentage of cells in each phase of the cell cycle was calculated by FACS analysis. Symbols: A: 200 μM ALA incubation; L: 0.1 J/cm² laser irradiation. Each data point represents the mean of three separate experiments; bars are the standard errors. *Statistical significant at p < 0.05 versus control.