Mechanism Analysis And Experiment Study Of Steep Pulse's Antitumor Effect

Cancer is the main disease which has been threatening human life, dozens of malignant tumor therapies come forth with their own dominance and deficiency. Today, the research is not limit to their cytocidal and inhibitory effect on tumor cell, but the anti-tumor effect on vessel, lymphatic, immunity system and apoptosis abduction.Steep pulse therapy (SPT) is a new physical therapy initiated by us. In forepassed experiments in cell line, BALB/c mice and tumor in vitro, we confirmed adequately its cytocidal and inhibitory effect on tumor cell. In this paper, experimental studies were developed from these four anti-tumor effects, they become conscious as follows: (1) Under the steep pulse field, tiny blood and lymphatic vessels were jammed or destroyed, the expression of VEGF-A and VEGF-C was descent, those mean that SPT can detain rudimental tumor cell transferring to other part by the way of blood and lymphatic vessel, and prevent tumor from proliferation and transfer. (2 )SPT can the proliferation of spleen lymphatic cell, arouse the activity of NK cell and huge-spit cell, enlarge latter secretion of IL-4 IFN and TNF-and then strengthen immunity function of organism (3) SPT can prohibit cellular proliferation, change cellular cycle, and induce cellular apoptosis by descending the expression ratio of Bcl-2/Bax to release the apoptosis factors,.Moreover, this paper analyses SPT's mechanism in killing tumor cell and inducing cellular apoptosis. (1) With ANASYS electromagnetic field analysis software and finite element method (FEM), electric field intensity (EFI) distribution in symmetrical medium is calculated. Combined with rabbit liver experiment, we find the relationship between electrode size distance between different electrode and electrode array arrangement and killing efficiency, select the EFI threshold leading liver cell to irreversible breakdown. (2) Single cell model is built to calculate the transmembrane potentials(TMP) in polar points. TMP curve follows exponential attenuation rule, the more narrow pulse width is, the faster attenuation pace is. During the electroporation, membrane conductivity raises, cellular radius prolongs, membrane thickness is thinner, because of these change, ascend time of TMP is shortened and attenuation pace slows down. (3) Compared with square pulse, SPT owns the more superior ultra high frequency (VHF) killing effect on organelle after frequency spectrum analysis, which means that SPT can induce cellular apoptosis, prevent organelle drifting away from destroyed membrane, stop the tumor transferring or recurring. The more narrow pulse width is, the higher killing effect of VHF part is. With these results, we can control freely the killing effect of SPT in proper scope with the best curative effect.