This was a study aimed to observe the proliferating ability inhibited by energy controllable steep pulse (ECSP) and to detect the expression of gene with relation to the proliferating ability of the tumor in breast cancer cell line; the possible mechanisms were also addressed. Human breast cancer cell line MDA-MB-231 was treated with ECSP; the apoptosis and the expression of tumor suppressor gene--Rb genes and E2F1 genes in ECSP group and control group were detected by TUNEL staining and Reverse Transcripitional PCR respectively. ECSP was found to inhibit the proliferating ability of breast cancer cells markedly, the cell amount in ECSP group decreased and the TUNEL positive cells increased obviously, compared to control; 24 hours after treatment the expression of Rb genes mRNA increased, whereas the expression of E2F1 mRNA decreased. These findings indicate that the proliferating ability of breast cancer cells can be inhibited by ECSP markedly, the apoptosis of breast cancer cell can be induced by ECSP, and the Rb genes and E2F1 genes may be involved in the course.
Apoptosis ; radiation effects ; Breast Neoplasms ; pathology ; Cell Line, Tumor ; Cell Proliferation ; radiation effects ; Electric Stimulation Therapy ; methods ; Electromagnetic Fields ; Electroporation ; methods ; Female ; Humans

In these years, the electrical technology is widely applied in the study of biomedical engineering. Using electroporation therapy (EPT) to treat tumor is associated with biomedical engineering, electrical new technology, computer technology and microelectronic technology, which is a new marginal subject. Many experts have studied the mechanism and clinical treatment of the cell membrane electroporation phenomenon under electrical fields. These researches have shown that the membrane electroporation can stimulate the transport and intake of various drugs, which improves the tumoricidal effect of these drugs. The researchers have also been exploring the phenomenon that irreversible electrical breakdown (IREB) of cell membrane under high electrical fields and steep pulses leads to the death of tumor.
Cell Membrane ; ultrastructure ; Electrochemotherapy ; Humans ; Neoplasms ; drug therapy ; Research ; trends

Experimental research of injury on tumor tissue in vitro is conducted with homemade energy-controllable steep pulse device. With the comparison of histological assay results between treatment group and non-treatment group, basic phenomenon of electrochemical reaction and pathology reaction of tumor tissue during the experiment is observed. The results showed the irreversible breakdown penetrating effect of energy-controllable steep pulse on tumor cells and the feasibility of this therapy are also demonstrated. These results provide a consolidate theoretic and applicable basis for further study on mechanism and animal experiment in vivo.
Electric Stimulation Therapy ; instrumentation ; methods ; Electromagnetic Fields ; Female ; Humans ; In Vitro Techniques ; Male ; Middle Aged ; Neoplasms ; pathology ; therapy

This experimental study was designed to investigate the effects and the expressions of microvessel density (MVD), vascular endothelial growth factor (VEGF) on the transplanted tumor in the rat model with Walker-256 after energy controllable steep pulse(ECSP). The experiment revealed that the steep pulse electrical field has better effect on tumor, compared with the control. The positive cell staining intensity of VEGF in the control group was significantly higher than that in ECSP group (P < 0.05). The number of MVD in the tumor tissues of ECSP group was significantly lower than that of tumor control group (P < 0.05). These results showed that ECSP could inhibit the growth and angiogenesis of tumor and its pathway is to down-regulate the expression of VEGF possibly.
Animals ; Carcinoma 256, Walker ; blood supply ; therapy ; Electric Conductivity ; Electric Stimulation Therapy ; methods ; Electromagnetic Fields ; Electroporation ; methods ; Female ; Male ; Neovascularization, Pathologic ; Rats ; Rats, Wistar ; Vascular Endothelial Growth Factor A ; metabolism

Pulsed electric fields can induce various kinds of biological effects that are essentially different from the normal electric fields, especially the interactions of Nanosecond Pulsed electric field (nsPEF) with cells. The biological effects of different pulsed electric fields on cell membranes, cytoplasmic matrixes, cell growth are introduced in this paper. Based on these effects, some applications of pulsed electric fields in cancer therapy, gene therapy, and delivery of drugs are reviewed in details.
Cell Membrane ; metabolism ; radiation effects ; Cell Physiological Phenomena ; Electromagnetic Fields ; Electrophysiology ; Electroporation ; Genetic Therapy ; methods ; Neoplasms ; therapy

Pulsed electric fields (PEFs) with fixed frequency, width and gradually increased peak value of voltage was applied to 30 healthy rabbit liver tissues. The specific aims were to explore the feasibility of establishing a model of in vivo PEFs distribution in healthy rabbit liver tissues and to provide important references for clinical electrochemotherapy and for electrotransfer. Repeated experiment and self-comparison statistics design were implemented. The rabbit underwent the experiment under intravenous anesthesia and their liver tissues, after exposure to PEFs, were sent for HE staining. Necrotic borderline was visible 3 days after PEFs application, the necrotic shape of concentric circle was evident around the electrodes under optical microscope at lower voltage, as voltage increasing, two necroses in the shape of concentric circle gradually enlarged; nuclei with chromatin condensation, fragmentation and lysis alterations were seen in the middle region between the needles; concentric circles changed into ellipse fusiform and finally overlaped each other forming irregular necrosis contours. Cell cavitation and tissues ischemia were also observed within electric field. The shape of tissue necrosis from the experiment was noted to correlate with theoretic simulation of electric field distribution. Therefore, rabbit liver tissues can be a good carrier for in vivo modeling of electric field distribution when the lethal effects of PEFs in tissues are investigated. PEFs also show safety for the surrounding normal tissue while causing damage or injury to the target area therapeutically.
Animals ; Electricity ; adverse effects ; Electrochemotherapy ; Liver ; pathology ; Male ; Models, Theoretical ; Necrosis ; Rabbits

In recent years, many experts have done some researches on experiment and mechanism of intracellular electromanipulation (IEM) under nanosecond pulsed electric field (nsPEF). The experiment results have shown that nsPEF could not induce electroporation of cell membrane, but could induce intracellular effects such as apoptosis, calcium release, enhancement of gene expression, and fragmentation of DNA and chromosome. In order to account for the phenomenon, researchers believe that when the pulse width of the pulsed electric field is larger than the charging time of plasma membrane, the pulsed electric field mainly targets on the outer membrane of cell; and that the effect of the pulsed electric field on nucleus and nuclear membrane increases with the decrease of the pulse width. It is also believed that the effect of electroporation changes from the outer membrane to intracellular electromanipulation when the pulse width decreases to a value being smaller than the charging time of plasma membrane.
Apoptosis ; Calcium ; metabolism ; Cell Membrane ; metabolism ; Cell Nucleus ; metabolism ; Cell Physiological Phenomena ; Electromagnetic Fields ; Electroporation ; Gene Expression

To investigate the lethal effect of steep pulsed electric fields (SPEFs) on cancer cells and the life-prolonging effect of SPEFs on the survival of tumour-bearing mice, this study was carried out with the use of SPEFs to treat 40 BALB/C mice inoculated by cervical cancer. The lethal effect on cancer cells and the life-prolonging effect on tumour-bearing mice were examined and compared between the experiment group and control group. The survival periods of the experiment group and control group were 52.05 days and 33.03 days, respectively. There was a significant difference in survival curve between the two groups. The results confirmed the inhibitiory effect and lethal effect of SPEFs on cancer cells. SPEFs can prolong the survival period of tumour-bearing mice.
Animals ; Electrodes ; Electromagnetic Fields ; Electroporation ; Female ; Mice ; Mice, Inbred BALB C ; Neoplasm Transplantation ; Pulse ; Survival Rate ; Uterine Cervical Neoplasms ; pathology ; therapy

The aim of our study was to determine the effects of energy controllable steep pulse (ECSP) on the cytoskeleton of human ovarian cancer cells SKOV3. SKOV3 cells were divided into five groups under ECSP treatment with different parameters (frequency, pulse duration, peak value of voltage). The positive control group included SKOV3 cells treated with volchicine; the negative control group included SKOV3 cells subjected to sham-lightning stroke. Rhodamine-phalloidine was used to label microfilament directly. After using immunofluorescence to label microbules, we observed them by means of Confocal Laser Scanning Microscope. Making specimen and using electronmicroscope, we observed the ultramicrostructure of cystoskeleton. The results showed that ECSP-treated-SKOV3 cells lost their normal cystoskeleton network structure. There were obvious microfilament disaggregation, diffused skeleton protein, and disappearance of cystoskeleton network structure. Also noticeable were microbule disaggregation, reduction of pseudopod, obvious microfilament disaggregation, permutation disorder and structure disappearance. Moreover, this effect bears a direct relation with dosage.
Cell Line, Tumor ; Cytoskeleton ; ultrastructure ; Electric Conductivity ; Electromagnetic Fields ; Electroporation ; Female ; Humans ; Ovarian Neoplasms ; pathology ; Pulse

This study was conducted to observe the lethal effects of steep pulsed electric field(SPEF) on the cancerous squamous cells in BALB/c mice. Female mice were inoculated with the solution of cervical cancer cells line. The tumor-bearing mice of the experiment group were exposed to SPEF. Then, the histomorphological changes were examined and compared between experiment group and control group. The histological and antitumor assay showed that SPEF could selectively injure tumor cells and inhibit cell proliferation. After treatment, pyknosis, karyoclasis and karyolysis of cancer cells were observed under light and electron mircroscope. More serious changes appeared some days later. These results indicate that SPEF have lethal effects on cervical cancer. It may prolong the survival period of tumor-bearing mice.
Animals ; Cell Line, Tumor ; Cell Proliferation ; Electromagnetic Fields ; Electroporation ; methods ; Female ; Mice ; Mice, Inbred BALB C ; Neoplasm Transplantation ; Uterine Cervical Neoplasms ; pathology