Abstract
Despite the status of cisplatin (DDP) as a classical chemotherapeutic agent in the treatment of cancer, the development of multidrug resistance often leads to a failure of DDP therapy. Here we found that phosphorylated cofilin-1 (p-cofilin-1) was overexpressed in the DDP-resistant human gastric cancer cell lines SGC7901/DDP and BGC823/DDP, relative to the respective parent cell lines (SGC7901 and BGC823), and that DDP induced the dephosphorylation of p-cofilin-1 in both parent lines but not in the DDP-resistant lines. However, we noted that the traditional Chinese medicine formula Zuo Jin Wan (ZJW) could induce the dephosphorylation of p-cofilin-1 and promote cofilin-1 translocation from the cytoplasm into the mitochondria in both SGC7901/DDP and BGC823/DDP cells. This mitochondrial translocation of cofilin-1 was found to induce the conversion of filamentous actin to globular-actin, activate mitochondrial damage and calcium overloading, and induce the mitochondrial apoptosis pathway. We further observed that these effects of ZJW on DDP-resistant human gastric cancer cell lines could be reversed via transfection with cofilin-1-specific siRNA, or treatment with a PP1 and PP2A inhibitor. These results suggest that ZJW is an effective drug therapy for patients with DDP-resistant gastric cancer.