Autophagy Inhibitor Spautin-1 Sensitizes Osteosarcoma Cells To Cisplatin-Induced Apoptosis And The Study On Sustained Selease Characteristics Of Cisplatin- Polymethyl Methacrylate Cement Compound

Part ? Autophagy Inhibitor Spautin-1 sensitizes osteosarcoma cells to cisplatin(?) induced apoptosisPurpose Osteosarcoma is derived from mesenchymal tissue. With its increasing incidence, osteosarcoma constantly affects the life quality of patients. Neoadjuvant chemotherapy is widely used in the treatment of osteosarcoma, the effect of preoperative chemotherapy surgery plays a decisive role. Continuous discovery and clinical application of chemotherapeutic agents for cancer treatment has a positive effect, but chemotherapy fails to improve the prognosis because of the emergence of resistance to chemotherapy. Therefore, making clear the chemotherapy-resistance molecular mechanism is of hreat important theoretical and practical significance for the treatment of osteosarcoma.Methods 1. To make clear the effect of Spautin-lon U2OS proliferation and apoptosis, CCK8 assay was performed to measure the effect of Spautin-1 on cell proliferation. Caspase activity detecting kit was used to detect the activity of caspases (Caspase-3,8, 9) involved in the endogenous and exogenous cell apoptosis pathway. Western blotting was performed to monitor the cleavage of caspases. The Annexin V labeled apoptosis positive cells were measured by flow cytometry.2. To explore the effect of Spautin-1 on cisplatin mediated cell proliferation inhibition. Cells were cultured and treated with cisplatin alone or combined with spautin-1, cell viability was measured by CCK8 assay.3. To explore the effect of Spautin-1 on cisplatin mediated apoptosis induction. Cells were cultured and treated with cisplatin alone or combined with spautin-1, cell apoptosis was measured by flow cytometry.4. To explore the effect of Spautin-1 on cisplatin mediated autophagy induction.Results 1. Spautin-1 has no obvious effect on cell proliferation and apoptosis. The cell viability and apoptosis rates of the control group and Spautin-1 treated group are nearly the same (P>0.05).2. Spautin-1 promotes the cell proliferation inhibition of cisplatin. The cell viability of cells decreased when combined treated with spautin-1 compared with cisplatin alone.3. Spautin-1 promotes the apoptosis induction by cisplatin. Flow cytometry showed that the apoptosis rates increased from 16.5% to 35.0%. The cleavage of caspase3 and PARP also increased.4. Spautin-1 can inhibit cisplatin induced autophagy. Western blotting showed that cisplatin can induce autophagy and spautin-1 can reverse this effect.Conclusions 1. Spautin-1 has no obvious effect on cell proliferation and apoptosis.2. Spautin-1 promotes the cell proliferation inhibition by cisplatin.3. Spautin-1 promotes the apoptosis induction by cisplatin.4. Spautin-1 can inhibit cisplatin induced autophagy.Part II The study on sustained release characteristics of cisplatin-Polymethyl methacrylate cement compoundPurpose Osteosarcoma is the most common primary malignant tumor, the method of local curettage commonly used in clinical surgery. This type of surgery could lead bone defect and local recurrence. Bone cement compound with chemotherapy drugs used as a clinical biological material for filling bone defects, and can play a partial role in the effects of local chemotherapy. Therefore, the bone cement as a chemotherapy drug delivery carriers has important theoretical and practical significance.Methods 1. To investigate the influence of high temperature to the biological activity of cisplatin:Cisplatin was dissolved in 0.9% normal saline at 75 ? for 10min, use osteosarcoma cells (U2OS) for the study, to explore the stability of biological activity of cisplatin.2. To investigate the physical properties of cisplatin-polymethyl methacrylate bone cement (PMMA):use the bone cement and cisplatin for the study, according to a certain proportion of mixed, detecting the physical properties of the compound.3. Use the bone cement-washing liquid and U2OS for the study:CCK8 method was used to study the biological activity of cisplatin.Results 1. The biological activity of cisplatin did not change significantly after treated by the high temperature.2. The physical properties of bone cement compound with cisplatin.3. The biological activity of cisplatin released from the bone cement has no significant changeConclusions 1. High temperature had no effect on chemotherapy drugs.2. Physical and chemical properties of the cisplatin-bone cement did not change significantly.3. The biological activity of durgs released from bone cement did not change significantly.