Ultrastructural changes in the nuclei of human carcinoma cells after photodynamic treatment with haematoporphyrin derivative and tetrasodium-meso-tetra-(4-sulphonatophenyl)porphine

Human NHIK 3025 cells derived from a carcinoma in situ were incubated with tetrasodium-meso-tetra-(4-sulphonatophenyl)porphine (TPPS₄) or HPD and exposed to light. Two different incubation conditions were applied: 0.5h in pure phosphate-buffered saline and 22h in a medium containing 10% newborn calf serum. The cell survival curves revealed different inactivation kinetics for TPPS₄ as compared with HPD. Electron microscopy revealed qualitatively the same types of photoinduced damage to the cell nuclei for both sensitizers when the cells were examined at the same survival level. The damage was manifested as nuclear swelling and segmentation, swelling of the perinuclear cistern, simultaneous chromatin dilution and condensation, and nucleolar segregation with cap formation. For HPD, mitotic arrest with disappearance of microtubules was also observed.