This study was conducted to investigate the anti-tumor efficacy of nanosecond pulsed electric fields (nsPEFs) on the mouse with A375-GFP melanoma xenograft in vivo. In vivo fluorescence image analysis system was used in this study to evaluate the effects of nsPEFs on human melanoma A375 cell xenograft. On the Day 90 af ter pulse delivery, the skin that had contained A375 cell xenograft was surgically excised and pathologically evalua ted. The changes of scar were recorded by digital camera. The experiment revealed that significant changes in fluorescence value trend and amplitude were found in the treated group from those in the control group. The fluorescence of tumor in the treated group decreased mostly 48 h after the treatment and completely disappeared 10 d after the treatment, while that in control group was increased gradually. Surgical excision of the area confirmed a complete pathologic response. Within a few days after the nsPEFs treatment, a hard scab formed at the treatment region. The scab fell off by the end of the second week. As time went on, the scar gradually became faded and all xenograft tumors were disappeared without recurrence. From the experiment, we learn that nsPEFs can bring good therapeutic effect. It may provide a new approach for the clinical treatment of superficial tumors.
Animals ; Electric Stimulation Therapy ; methods ; Heterografts ; Humans ; Melanoma ; therapy ; Mice ; Neoplasm Recurrence, Local ; Skin ; pathology

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

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

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

To assess study the cytocidal and inhibitory effects of steep pulsed electric fields (SPEFs) on ovarian cancer cell line SKOV3, the cancer cell suspension was treated by SPEFs with different parameters (frequency, pulse duration, peak value of voltage). Viability rate and growth curves of two test groups (high dosage and low dosage of SPEFs) and one control group were also measured. The DNA contents and cell cycle were analyzed by flow cytometry (FCM). Different dosing levels of SPEFs exerted obviously different effects on cancer cell viability. With the enhancement of each pulse parameter, the viability rate was promoted and the inhibitory effect on the proliferation of treated cells was more evident. The cells exposed to SPEFs grew slower than the control. The ratio of S+G2/M phase cells was decreased, which restrained the DNA synthesis and division, but the ratio of G0/G1 phase cells was increased in the treated groups. It was also indicated that the SPEFs blocked the cell transition from G0/G1 phase to S+G2/M phase. There was a significant difference in cell cycle between treated group and control group (P<0.01). Lethal effects of SPEFs were represented by inhibiting the cancer cell proliferation at the cell level and by influencing the cell cycle at the DNA level.
Adenocarcinoma ; pathology ; Cell Cycle ; radiation effects ; Cell Line, Tumor ; Cell Proliferation ; radiation effects ; DNA ; analysis ; Electromagnetic Fields ; Electroporation ; Female ; Flow Cytometry ; Humans ; Ovarian Neoplasms ; pathology ; Pulse

This experiment was designed to study the apoptosis and related mechanism of adherent liver tumor cells (SMMC-7721) and adherent normal liver cells (HL-7702) when they were exposed to the steep pulse generated by the steep pulse apparatus for tumor treatment. The results showed that the steep pulse of 200 V could induce tumor cells apoptosis. The tumor cells presented with their apoptosis when they were exposed to the steep pulse from 200 V to 250 V. Laser scanning confocal microscopy was used to make a real time study of calcium burst when the adherent tumor cells were exposed to the steep pulse. The results showed:On the condition of no extracellular Ca2+, the concentration of Ca2+ in tumor cells exposed to the steep pulse of 150 V did not change; the concentration of Ca2+ in tumor cells exposed to the steep pulse of 200 V decreased; the concentration of Ca2+ in tumor cells exposed to the steep pulse of 250 V decreased more evidently. On the condition of existing extracellular Ca2+, the concentration of Ca2+ in tumor cells exposed to the steep pulse of 150 V did not change; the concentration of Ca2+ in tumor cells exposed to the steep pulse of 200 V decreased little; the concentration of Ca2+ in tumor cells exposed to the steep pulse of 250 V reduced little, too. Maybe the change of calcium burst in the tumor cells is the mechanism of apoptosis when cells are exposed to the steep pulse.
Apoptosis ; radiation effects ; Calcium ; metabolism ; Electricity ; Electromagnetic Fields ; Hepatocytes ; cytology ; pathology ; Humans ; Liver Neoplasms ; metabolism ; pathology ; Microscopy, Confocal ; Tumor Cells, Cultured

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

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

This paper is to investigate the apoptosis effect of ovarian cancer SKOV3 cells induced by nanosecond plused electric fileds (nsPEFs) and to study its influence on Fas-mediated apoptosis. SKOV3 cell were exposed to the 45kV/cm of field intensity, 30 pulses, and 50ns, 100ns, and 200ns of pulse width, respectively. Flow cytometry were used to assay apoptosis. Agarose gel electrophoresis was used to detect DNA ladder. Real time PCR (RT-PCR) and Western blot analysis were used to measure the expression level of Fas, FasL, caspase-8 and Bid. Flow cytometry results revealed that the late apoptosis rates and (or) necrosis were significantly higher than those in control group (3.03% +/- 0.57%) (P < 0.05), with apoptosis rates and (or) necrosis being (18.31 +/- 0.65%), (45.55% +/- 3.71%), (47.47% +/- 7.01%) in the groups of 50ns, 100ns, 200ns, respectively. A typical DNA ladder pattern of internucleosomal fragmentation was observed in the groups of 50ns and 100ns, but not clear in the 200ns group. RT-PCR results revealed that the mRNA expression of Fas, FasL, caspase8 and Bid were significantly increased in groups of 50ns, 100ns, but significantly decreased in group of 200ns (P < 0.05). Meanwhile, Western blot analysis demonstrated that the Fas, FasL, Caspase-8 and Bid expression were significantly higher in groups of 50ns, 100ns, but significantly lower in group of 200ns (P < 0.05). It indicated that 45kV/cm, 50ns, 100ns nsPEFs could induce apoptosis in ovarian cancer SKOV3 cells and activate Fas-mediated apoptosis pathway.
Apoptosis ; radiation effects ; Caspase 8 ; metabolism ; Cell Line, Tumor ; Electromagnetic Fields ; Electroporation ; methods ; Fas Ligand Protein ; Female ; Humans ; Ovarian Neoplasms ; pathology ; fas Receptor ; metabolism

Physical ablation is a new kind of tumor treatment which directly acts on local solid tumors to eradicate or destroy tumor tissues by use of various advanced physical techniques. Physical ablation can be classified by physical characteristics as thermal ablate therapy (TAT), cryoablation and electrical ablation. Recent studies and technical trend of these three physical ablation treatments are reviewed in this paper.
Animals ; Catheter Ablation ; methods ; Cryosurgery ; Humans ; Hyperthermia, Induced ; Neoplasms ; surgery ; therapy ; Salvage Therapy