[Effects of photodynamic therapy on cell kinetics of cultured human cancer cells in reference to its cytocidal effects].
Photodynamic therapy (PDT) for cancer is a relatively new technique that has been used clinically in the treatment of a variety of neoplasms. In this report, the effects of PDT on cell kinetics of the two cultured human lung cancer cell lines (PC-6, PC-9) were investigated in reference to its cytocidal effects. The cellular uptake of hematoporphyrin derivative (HpD) was dependent on external HpD concentration. And in the same external HpD concentration, PC-9 cells incorporated more HpD than did PC-6 cells. On the other hand, PC-6 cells were more susceptible to PDT than did PC-9 cells. This finding is explainable for the reason that PC-6 cells incorporate more HpD per unit protein content in single cells than do PC-9 cells. Analysis of DNA histogram obtained by flow cytometry showed that a shift in the histogram peak to hypodiploid occurred at severe cytocidal effect of PDT, and this finding expressed the cell killing characterized by cell lysis after PDT. At moderate cytocidal effect of PDT, a prolongation of G2/M phase of the cell cycle caused by the inhibition of protein synthesis was observed. And partial synchronization was ascertained. These findings indicate the possibility for synergistic antitumor effect of PDT in combination with other therapies.
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Tsuji
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Fujikane
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Sakai
D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D008175:Lung Neoplasms / Q000473:pathology; D010778:Photochemotherapy; D014407:Tumor Cells, Cultured / Q000187:drug effects*