Bioelectromagnetic Field Effects on Cancer Cells and Mice Tumors

We present possibilities and trends of ELF bioelectromagnetic effects in the mT amplitude range on cancer cells and on mice bearing tumors. In contrast to invasive electrochemotherapy and electrogenetherapy, using mostly needle electrodes and single high-amplitude electropulses for treatment, extremely low-frequency (ELF) pulsating electromagnetic fields (PEMF) and sinusoidal electromagnetic fields (SEMF) induce tumor cell apoptosis, inhibit angiogenesis, impede proliferation of neoplastic cells, and cause necrosis non invasively, whereas human lymphocytes are negligibly affected. Our successful results in killing cancer cells—analyzed by trypan blue staining or by flow cytometry—and of the inhibition of MX-1 tumors in mice by 15–20?mT, 50?Hz treatment in a solenoid coil also in the presence of bleomycin are presented in comparison to similar experimental results from the literature.

In conclusion, the synergistic combinations of PEMF or SEMF with hyperthermia (41.5°C) and/or cancerostatic agents presented in the tables for cells and mice offer a basis for further development of an adjuvant treatment for patients suffering from malignant tumors and metastases pending the near-term development of suitable solenoids of 45–60?cm in diameter, producing >20?mT in their cores.     

Inhibiting effects of nicotinamide on urethane-induced malformations and tumors in mice

The antipellagratic vitamin, nicotinamide, significantly suppressed urethane-induced malformations, when it was given intraperitoneally to pregnant JCL:ICR mice immediately after a single subcutaneous injection of urethane (1.0 mg/g) on the 9th day of gestation. The level of inhibition increased with the doses of nicotinamide: 33.0, 55.8, and 70.0% at doses of 0.1, 0.3, and 0.5 mg/g, respectively. Polydactyly and tail anomalies were markedly suppressed by the post-treatment with nicotinamide, while cleft palates were less effectively suppressed. Nicotinamide was still effective, when it was given during the period of 24-48 h after urethane treatment. Furthermore, dietary administration of nicotinamide also reduced urethane-induced malformations. The level of inhibition was 39.4 and 61.1% at 0.5 and 1.0% of nicotinamide in the diet, respectively. Higher doses of nicotinamide (3 and 5% in diet) also inhibited urethane-induced malformations, but not so effectively as lower doses. The inhibiting effects of nicotinamide on the spontaneous incidence of cleft lips and palates in CL/Fr mice were significant at a low dose (0.5% in diet), but not at a higher dose (1.0%). When [carbonyl-14C]nicotinamide was given to pregnant mice, nicotinamide and small amounts of nicotinamide adenine dinucleotide (NAD+), but not nicotinic acid, were detected chromatographically in the fetus and placenta, indicating that nicotinamide or NAD+ acts directly on the fetus to suppress urethane-induced malformations. A preliminary study revealed that urethane-induced lung tumorigenesis in JCL:ICR mice was also inhibited by post-treatment with nicotinamide in the diet. The level of inhibition was proportional to the dose of nicotinamide, that is, 35.0 and 62.8% at 1.0 and 2.5% of nicotinamide in the diet, respectively.     

The effects of pulsed magnetic field exposure on the permeability of leukemia cancer cells

Purpose: The newer methods of cancer treatment require new idea of drug delivery in cancer cells. Due to numerous researches electromagnetic field affect on cell function and cell membrane for possible therapeutic and drug delivery. In this article, we determined in vitro uptake of fluorescent dyes into the attached K562 cells due to time-varying magnetic field exposure. Method and material: The K562 cells were exposed to magnetic pulses via Magstim stimulator and double 70?mm coil. The strength and duration of pulses in all experiments were the same and three different frequencies of 0.25, 1 and 10?Hz pulses for 56, 112 and 28 numbers of pulses were applied (nine experimental groups) and uptake of Ly and PI was measured in each group. Result: Our results show that magnetic field can efficiently increase permeability. Among the treatment groups, the system gives the optimal permeabilization when cells are exposed to a train of 28 pulses with 1?Hz frequency.     

Antimutagenic effects on male germ cells of mice

The alkylating agent cyclophosphamide (CPA) and the antioxidant ethoxyquin (EQ) were administered perorally to NMRI mice. The strong clastogenic action of CPA on spermatogonia was diminished by simultaneous doses of EQ. Higher doses of the antioxidant produced greater anticlastogenic action. Furthermore, the action of the mutagen and the antioxidant on the late spermatids and the spermatozoa was observed using the dominant lethal test. The antioxidant had only a weak influence on these postmeiotic stages.     

Effect of centimeter microwaves and the combined magnetic field on the tumor necrosis factor production in cells of mice with experimental tumors

The effect of fractionated exposure to low-intensity microwaves (8.15-18 GHz, 1 microW/cm2, 1.5 h daily for 7 days) and combined weak magnetic field (constant 65 1 microT; alternating--100 nT, 3-10 Hz) on the production of tumor necrosis factor in macrophages of mice with experimental solid tumors produced by transplantation of Ehrlich ascites carcinoma was studied. It was found that exposure of mice to both microwaves and magnetic field enhanced the adaptive response of the organism to the onset of tumor growth: the production of tumor necrosis factor in peritoneal macrophages of tumor-bearing mice was higher than in unexposed mice.     

Light at night and melatonin have opposite effects on breast cancer tumors in mice assessed by growth rates and global DNA methylation

Light-at-night (LAN) is a worldwide problem co-distributed with breast cancer prevalence. We hypothesized that exposure to LAN is coincided with a decreased melatonin (MLT) secretion level, followed by epigenetic modifications and resulted in higher breast cancer tumors growth-rate. Accordingly, we studied the effect of LAN exposure and exogenous MLT on breast cancer tumors growth-rate. 4T1 cells were inoculated into BALB/c short day-acclimated mice, resulting in tumors growth. Growth rates were followed under various light exposures and global DNA methylations were measured. Results demonstrated the positive effect of LAN on tumors growth-rate, reversed by MLT through global DNA methylation.     

Senescent cells in growing tumors: population dynamics and cancer stem cells

Tumors are defined by their intense proliferation, but sometimes cancer cells turn senescent and stop replicating. In the stochastic cancer model in which all cells are tumorigenic, senescence is seen as the result of random mutations, suggesting that it could represent a barrier to tumor growth. In the hierarchical cancer model a subset of the cells, the cancer stem cells, divide indefinitely while other cells eventually turn senescent. Here we formulate cancer growth in mathematical terms and obtain predictions for the evolution of senescence. We perform experiments in human melanoma cells which are compatible with the hierarchical model and show that senescence is a reversible process controlled by survivin. We conclude that enhancing senescence is unlikely to provide a useful therapeutic strategy to fight cancer, unless the cancer stem cells are specifically targeted.     

Proteomic profiling of cancer stem cells derived from primary tumors of HER2/Neu transgenic mice

Human epidermal growth factor receptor 2 (HER2) overexpression leads to mammary tumorigenesis and its elevated levels lead to increase in cancer stem cells (CSCs), invasion, and metastasis. CSCs are resistant to radiation/chemotherapeutic drugs and are believed to be responsible for recurrence/relapse of cancer. CSCs are isolated using flow cytometry based sorting, although reliable, this technology hinders the convenient identification of molecular targets of CSCs. Therefore to understand the molecular players of increased CSC through HER2 overexpression and to develop meaningful targets for combination therapy, we isolated and characterized breast CSCs through convenient tumorsphere culture. We identified the altered protein expression in CSC as compared to non‐CSC using LC‐MS/MS and confirmed those results using qRT‐PCR and Western blotting. Ferritin heavy chain 1 (FTH1) was identified as a candidate gene, which is involved in iron metabolism and iron depletion significantly decreased the self‐renewal of CSCs. We further performed in silico analysis of altered genes in tumorsphere and identified a set of genes (PTMA, S100A4, S100A6, TNXRD1, COX‐1, COX‐2, KRT14, and FTH1), representing possible molecular targets, which in combination showed a promise to be used as prognostic markers for breast cancer.     

Magnetic field effects on assembly pattern of smooth muscle cells

Summary Under a strong magnetic field, the diamagnetic, properties of biological cells modulate the behavior of the cells themselves, under conditions of both floating and adherence. The morphological effects of strong static magnetic fields on adherent cells are less well understood than the effects of magnetic fields on red blood cells. In the present study, a high-intensity magnetic field of 14 T affected the morphology of smooth muscle cell assemblies, and the shapes of the cell colonies extended along the direction of the magnetic flux. The phenomenon was most notable, under magnetic fields of more than 10 T, where an ellipsoidal pattern of smooth muscle cell colonies was clearly observed. The ellipticity of the cell colony pattern with a 14-T magnetic field was 1.3, whereas that with a field of 0–8 T was close to a circle at about 1.0. The evidence that smooth muscle cells detect high-density magnetic flux and thus change their cell orientation was shown as a visible pattern of cellular colonies. The speculated mechanism is a diamagnetic torque force acting on cytoskeleton fibers, which are dynamically polymerizing-depolymerizing during cell division and cell migration.     

Thoughts about cancer stem cells in solid tumors

Cancer chemotherapy efficacy is frequently impaired by either intrinsic or acquired tumor resistance.A fundamental problem in cancer research is identifying the cell type that is capable of sustaining neoplastic growth and its origin from normal tissue cells.In recent years,the cancer stem cell(CSC) theory has changed the classical view of tumor growth and therefore the therapeutic perspective.Overcoming intrinsic and acquired resistance of cancer stem/progenitor cells to current clinical treatments represents a major challenge in treating and curing the most aggressive and metastatic cancers.On the other hand,the identification of CSCs in vivo and in vitro relies on specific surface markers that should allow the sorting cancer cells into phenotypically distinct subpopulations.In the present review,recent papers published on CSCs in solid tumors(breast,prostate,brain and melanoma) are discussed,highlighting critical points such as the choice of markers to sort CSCs and mouse models to demonstrate that CSCs are able to replicate the original tumor.A discussion of the possible role of aldehyde dehydrogenase and CXCR6 biomarkers as signaling molecules in CSCs and normal stem cells is also discussed.The author believes that efforts have to be made to investigate the functional and biological properties of putative CSCs in cancer.Developing diagnostic/prognostic tools to follow cancer development is also a challenge.In this connection it would be useful to develop a multidisciplinary approach combining mathematics,physics and biology which merges experimental approaches and theory.Biological models alone are probably unable to resolve the problem completely.     

ELF fields and photooxidation yielding lethal effects on cancer cells

The lethal effect on human cancer cells was studied under three types of treatment: A) an ELF pulsed sinusoidal of 50 Hz electromagnetic field (PEMF) with amplitudes between 10 and 55 mT; B) the field and a cytostatic agent (actinomycin-C); and C) the field, the cytostatic agent, which has a photodynamic effect, and exposure to a halogen lamp. The results show a decreasing vitality of human K-562 and U-937 cancer cells in suspension with each additional treatment. Combination with other parameters as hyperthermia and/or hyperacidity could yield high killing rates by this noninvasive method.     

Long-term effects of splenectomy on immunocompetent cells of adult mice

The long-term effects of adult splenectomy on immunocompetent cells was studied in BALB/c mice during an observation period of 600 days following splenectomy in comparison to age-matched controls. The percentage and absolute number of circulating Thy 1.2-positive (T) cells diminished gradually, reaching about 50% of the level of T cells in age-matched controls, with a concomittant increase in the proportion of Ig-positive (B) cells. The in vitro response of peripheral blood lymphocytes (PBL) to T-cell mitogens showed a 60% decrease of [³H]TdR uptake following phytohemagglutinin stimulation without a significant impairment of the responsiveness to concanavalin A. Alloreactivity of PBL was unaltered by splenectomy since both the in vitro reactivity of PBL to allogeneic cells using mixed leukocyte reaction, and the in vivo assay, measuring a first set skin allograft survival, were similar to those observed in age-matched controls. Studies on the humoral antibody responsiveness to sheep red blood cells (SRBC) indicated a diminished primary, and normal secondary anti-SRBC responses in splenectomized mice. No IgG response was detectable in mice primed with SRBC starting at 160 days following splenectomy, whereas normal IgG titers were observed following SRBC boost in splenectomized mice. We conclude that the spleen seems to play a regulatory role on some immune functions during adult life in mice.     

Suspension osteopenia in mice: Whole body electromagnetic field effects

Whole-body fields were tested for their efficacy in preventing the osteopenia caused by tail suspension in mice. The fields had fundamental frequencies corresponding to the upper range of predicted endogenous impact-generated frequencies (0.25–2.0 kHz) in the long bones. Three distinct whole-body EMFs were applied for 2 weeks on growing mice. Structural, geometric, and material properties of the femora, tibiae, and humeri of suspended mice were altered compared to controls. Comparison of suspended mice and mice subjected to caloric restriction indicates that the changes in caloric intake do not explain either the suspension or the field-induced effects. In agreement with past studies, rather, unloading appears to cause the suspension effects and to be addressed by the EMFs. The EMF effects on bone properties were apparently frequency dependent, with the lower two fundamental frequencies (260 and 910 Hz) altering, albeit slightly, the suspension-induced bone effects. The fields are not apparently optimized for frequency, etc., with respect to therapeutic potential; however, suspension provides a model system for further study of the in vivo effects of EMFs. © 1995 Wiley-Liss, Inc.     

耐受性树突状细胞预防和治疗卵清蛋白过敏小鼠的的研究

目的 比较腺病毒重组CTLA4Ig/α4β7诱导的耐受性树突状细胞对卵清蛋白(OVA)致敏小鼠的预防和治疗效果.方法 BALA/c小鼠32只,分为4组.基础致敏24h后回输耐受性树突状细胞为预防组;肠道激发4h后回输耐受性树突状细胞为治疗组;回输生理盐水为阴性对照组和OVA过敏小鼠为阳性对照组.观察各组小鼠过敏症状缓解情况;HE染色观察空肠形态;甲苯胺兰染色观察小肠固有层肥大细胞聚集及脱颗粒现象;ELISA测定各组血清中OVA特异性IgE水平.结果 与阳性对照组相比,治疗组小鼠OVA特异性IgE水平显著降低(0.25±0.05 vs 0.17±0.03) (P ＜0.05);体重增长明显(3.16 g±0.75 g vs 5.04 g±0.49 g)(P ＜0.05);腹泻症状减轻;HE染色可见治疗组小肠绒毛中上皮细胞局灶性坏死、脱落,固有层炎症细胞浸润现象明显改善;肥大细胞聚集和脱颗粒现象改善.而预防组较阳性对照组过敏症状、小肠形态学及OVA特异性IgE水平差异均无统计学意义.结论Ad CTLA4Ig/Adα4β7修饰的致耐受性树突状细胞对卵清蛋白过敏小鼠具有治疗作用而无预防作用.