Effects of Photofrin-mediated photodynamic treatment on sensitivity to cisplatin in HeLa cells and the resistant subline

摘要

Cisplatin (CDDP) is a widely used platinum-based compound that is effective against a broad spectrum of solid neoplasms. Although CDDP often leads to an initial therapeutic success, associated with partial responses or disease stabilization, many patients are intrinsically resistant to cisplatin-based therapies. The essential cytotoxic factors of photodynamic treatment (PDT) are reactive oxygen species (ROS). The reaction of ROS with cytoplasmic peptides and proteins may reduce the degree of inactivation of CDDP. In this study, we applied low-level PDT, which demonstrated no remarkable cytotoxic effects on CDDP-resistant HeLa cells (HeLa/CDDP) and examined whether PDT can reduce the CDDP-resistance level. There were no remarkable cytotoxic effects without CDDP in the PDT. The viability of the HeLa/CDDP-PDT group at a CDDP concentration of 10 礛 was equal to that of normal HeLa cells. These findings suggest that PDT, which does not have sufficient cytotoxic effects, reduces the resistance level of HeLa/CDDP.