Table 1.

Quantification of apoptotic cells by IHC to c-PARP and active caspase-3 and -7 in paraffin-embedded section of control^a and paclitaxel^b or Foscan-photosensitized^c HT29 spheroids

	Apoptotic indexd
Markers	Control cells	Paclitaxel	Foscan-PDT
Active caspase-3	17.4 ± 3.0	34.7 ± 1.9	38.4 ± 0.4
Active caspase-7	17.0 ± 4.4	32.3 ± 7.1	40.3 ± 3.8
c-PARP	9.1 ± 2.3e	32.4 ± 2.2	41.3 ± 0.7

^aControl tumors were obtained from both untreated HT29 and non-irradiated cell spheroids.

^bHT29 spheroids were incubated with 0.1 μM paclitaxel for 48 hr.

^cHT29 spheroids were subjected to 4.5 μM Foscan for 24 hr before irradiation (10 mW/cm², 5 J/cm²).

^dMean ± SD of at least three experiments.

^eSignificantly different (p<0.05).

c-PARP, cleaved poly-ADP-ribose polymerase; PDT, photodynamic treatment.