Cellular uptake, subcellular localization and photodamaging effect of Temoporfin (mTHPC) in nasopharyngeal carcinoma cells: comparison with hematoporphyrin derivative

Temoporfin (meta-tetra (hydroxyphenyl)chlorin; mTHPC) potentiated a 100-fol d higher cytotoxic effect than hematopor phyrin derivative (HPD) on two nas opharyngeal carcinoma cell lines (HK1 and CNE2) in terms of the overall pho todynamic therapy (PDT) dose. The cellular uptake, evaluated by Row cytomet ry and spectrophotometry demonstrated that mTHPC exhibited higher uptake ab ility than HPD. Confocal laser scanning microscopy detection for both the s ensitizer and mitochondria probe on the same cell images revealed that both drugs accumulated diffusely in the cytoplasm and that mitochrondria is a t arget organelle. Photo-activation ruptured the mitochrondria. with more pro nounced mitochondnal damage being observed in mTHPC-PDT course. This correl ated well with the cell photokilling efficiency of mTHPC. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.