ABSTRACT
Resistance to cisplatin (DDP)-based chemotherapy is a major cause of treatment failure in human gastric cancer (GC). It is necessary to identify the drugs to re-sensitize GC cells to DDP. In our previous research, Zuo Jin Wan Formula (ZJW) has been proved could increase the mitochondrial apoptosis via cofilin-1 in a immortalized cell line, SGC-7901/DDP. Due to the immortalized cells may still difficult highly recapitulate the important molecular events in vivo, primary GC cells model derived from clinical patient was constructed in the present study to further evaluate the effect of ZJW and the underlying molecular mechanism. Immunofluorescent staining was used to indentify primary cultured human GC cells. Western blotting was carried out to detect the protein expression. Cell Counting Kit-8 (CCK-8) was used to evaluate cell proliferation. Flow cytometry analysis was performed to assess cell apoptosis. ZJW inhibited proliferation and induced apoptosis in primary DDP-resistant GC cells. Notably, the apoptosis in GC cells was mediated by inducing cofilin-1 mitochondrial translocation, down-regulating Bcl-2 and up-regulating Bax expression. Surprisingly, the level of p-AKT protein was higher in DDP-resistant GC cells than that of the DDP-sensitive GC cells, and the activation of AKT could attenuate ZJW-induced sensitivity to DDP. These data revealed that ZJW can increase the chemosensitivity in DDP-resistant primary GC cells by inducing mitochondrial apoptosis and AKT inactivation. The combining chemotherapy with ZJW may be an effective therapeutic strategy for GC chemoresistance patients.
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Apoptosis , Cell Proliferation , Cisplatin , Pharmacology , Therapeutic Uses , Cofilin 1 , Metabolism , Drug Resistance, Neoplasm , Drugs, Chinese Herbal , Pharmacology , Mitochondria , Metabolism , Pathology , Proto-Oncogene Proteins c-akt , Metabolism , Proto-Oncogene Proteins c-bcl-2 , Metabolism , Stomach Neoplasms , Drug Therapy , Metabolism , Pathology , Tumor Cells, CulturedABSTRACT
OBJECTIVE 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.Traditional Chinese medicine(TCM)as adjuvant chemotherapy of cancer drugs in China has been widely used in cancer treatment.ZuoJin WAN (ZJW),a TCM formula,was proved reversing drug resistance in gastric cancer,but its exact mechanism was still unclear. METHODS CCK-8 assay was used to detect the cell viability. The levels of proteins and mRNA were evaluated using Western blot and q-PCR. Mitochondrial membrane potential was measured by fl ow cytometry. Depolymerisa-tion of F-actin and translocation of G-actin(gamma-actin)from the cytoplasm to the mitochondria was detected using an immuno fl uorescence assay. RESULTS phosphorylated coflin-1 (p-coflin-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 DDP induced the dephosphory-lation of p-coflin-1 in both parent lines but not in the DDP-resistant lines. However, ZJW could induce the dephosphorylation of pcoflin-1 and promote coflin-1 translocation from the cytoplasm into the mito-chondria in both SGC7901/DDP and BGC823/DDP cells. This mitochondrial translocation of coflin-1 was found to induce the conversion of flamentous actin to globular-actin, activate mitochondrial dam-age and calcium overloading, and induce the mitochondrial apoptosis pathway. These effects of ZJW on DDP-resistant human gastric cancer cell lines could be reversed via transfection with coflin-1-specifc siRNA,or treatment with a PP1 and PP2A inhibitor.CONCLUSION ZJW can be used as an inhibitor of chemoresistance in gastric cancer, which may partly be due to dephosphorylation of p-coflin-1 via the activation of PP1 and PP2A.