| Objective: Chemotherapy is very important in ovarian cancer therapies, and cannot be substituted by any other therapies, such as surgery, irradiation and so on. The effect of chemotherapy directly decides the prognosis of patients. Inherent drug resistance and acquired drug resistance are the major problems in chemotherapy. There is no doubt that conquering drug resistance will provide new hopes to patients. It is a pity that the mechanisms by which cancer cells survive from the cytotoxic effects of chemotherapeutic agents are essentially unknown. Many types of chemotherapeutic drugs kill tumor cells through inducing apoptosis, and cisplatin(DDP), the first line chemotherapeutic agents of ovarian cancer is one of these. It is hypothesized that the ability of escaping apoptosis result in the ability of drug resistance. Apoptosis is an extremely complex process , and modulated by many factors. Recently, the relationship between integrins and apoptosis interesting more and more researchers. Cells are surrounded by extracellular matrix (ECM). Cells contact with ECM by adhesion molecules. Integrins is a family of adhesionmolecules on cell surface. Different integrins adhere to different kind of ECM ligands, and so to keep cells survive. Without adhesion, cells are more easily to apoptosis. Integrins contribute to drug resistance by inhibiting cell apoptosis. Integrins can also inhibit chemotherapeutic agents induced apoptosis. Cell Adhesion Mediated Drug Resistance (CAM-DR) is named to describe this phenomenon. Integrins are generally expressed in many types tissues including normal tissues, benign and malignant tissues, but integrin αvβ6 is expressed restricted to epithelial malignant tissues. It has been reported that integrin αvβ6 exists in ovarian malignant tissues, but not in normal and benign tissues, and is correspond with stages, the later stage the higher integrin αvβ6, so it can be a marker of the malignancy of ovarian cancer. We investigate the effect of cisplatin on ovarian cancer cell apoptosis and the influence of integrin αvβ6 mediated adhesion on cisplatin- induced cell apoptosis.Methods: Ovarian cancer cell lines SKOV3,AO,3AO were planted on 6-well plate in the same density and maintained in RPMI-1640 containing 10% FBS in 37.5°C, 5% CO2 for 24 hours, then the expression of integrin αvβ6 was measured by Flow Cytometry. Treat cell lines SKOV3,AO,3AO with different concentration of DDP for 48 hours, then cell proliferation inhibitory was measured by MTT, and cell apoptosis was measured by ELISA and AO/EB staining, and an optimal concentration of DDP was chosen. Treat celllines SKOV3,AO,3AO that plante on fibronectin(FN) and non-integrin ligand polylysin coated wells with DDP in the optimal concentration for 48 hours, and then investigate the expression of PI-3K and Bcl-2 by Flow Cytometry.Result: 1. By Flow Cytometry, we got the result that ovarian cancer cell lines SKOV3,AO,3AO all express integrin αvβ6 in the same high level(P>0.05). 2. ELISA result: DDP can induce ovarian cancer cell lines SKOV3,AO,3AO apoptosis significantly, even the lowest concentration (5ug/ml), and it is concentration dependent (P<0.01). 3. AO/EB staining result:when cells treated without DDP there were lots of normal but a few apoptotic cells, and the higher concentration of DDP the more apoptotic cells, and there were necrosis cells in the largest concentration of DDP(20ug/ml)(P<0.01). 4. When cells were cultured on FN coated wells, there were few apoptotic cells compared with cells cultured on polylysin coated wells, and these phenomenon could be partly abolished by inhibitory antibody against integrin αvβ6. 5. After treated with DDP for 48 hours, cell lines SKOV3,AO,3AO that planted on fibronectin (FN) expressed higher levels of PI-3K and Bcl-2 than those planted on non-integrin ligand polylysin coated wells investigate by Flow Cytometry (P<0.05).Conclusions: Ovarian cancer cell lines express integrin αvβ6 generally. Cell lines SKOV3,AO,3AO were sensitive to D...
|
PDF Full Text Request