The Study Of Apoptosis And Mechanism Of Cells Exposed To Steep Pulse

Malignant tumor is a kind of disease that seriously imperil the health as well as lives of human beings. Characteristics of malignancies include uncontrolled proliferation, invasion and metastasis. Although there are many methods to treat this disease, no one is ideal. Many experts are studying on it, and they bring us a new method which can reduce the affliction of radiotherapy and chemotherapy. Namely, use high intensity electric field to kill tumor cells, in order to cure the cancer. This method has theory and actual meanings to tumor treatment.The main work and conclusions were as following:1. Annexin V—FITC Kit and Flow Cytometry were used to study the apoptosis of cell SMMC-7721 and HL-7702 when exposed to different steep pulse. The results showed : The pulse of 200V/cm 1.8μs could make tumor cells apoptosis. The tumor cells and normal cells all turned up their apoptosis, when they were exposed to the steep pulse from lower to higher. At the same condition, more apoptosis happened in tumor cells.2. DNA Ladder Kit was used to study the change of DNA, when the tumor cells exposed to different steep pulse. The results showed: With the increase of steep pulse, DNA in tumor cells broke into smaller pieces.3. LSCM and Fluo-3 were used to make a real time study of calcium burst when the tumor cells were exposed to the steep pulse. The study showed: With the increase of steep pulse, the concentration of Ca²⁺in tumor cells exposed to the steep pulse of 1.8μs decreased more evidently; Under the same steep pulse, the concentration of Ca²⁺ in tumor cells with no extracellular Ca²⁺ decreased more evidently than the concentration of Ca²⁺ in tumor cells with extracellular Ca²⁺.4. Rhodamine 123 and LSCM were used to make a real time study of mitochondrial membrane potential when the tumor cells were exposed to different steep pulse. The study showed: With the increase of steep pulse,the mitochondrial membrane potential in tumor cells exposed to the steep pulse of 1.8μs decreased more evidently.5. The apoptosis, calcium burst and mitochondrial membrane potential were studied when the tumor cells exposed to the steep pulse of 600V/cm 120ns. The study showed: There was no apoptosis in tumor cells; on the condition of existing extracellular Ca²⁺, the concentration of Ca²⁺in tumor cells decreased little; on the condition of no extracellular Ca²⁺, the concentration of Ca²⁺in tumor cells decreased mostly; the mitochondrial membrane potential in tumor cells decreased mostly.These results were analysed and discussed on the base of existing theory and knowledge. The tumor cells happened to be apoptosis under steep pulse. Maybe the change of calcium burst and the mitochondrial membrane potential in the tumor cells were the mechanism of apoptosis when cells were exposed to the steep pulse .