The Static Magnetic Field Remotely Boosts the Efficiency of Doxorubicin through Modulating ROS Behaviors

Electromagnetic fields regulate iron metabolism in living organisms: A review of effects and mechanism

The emergence, evolution, and spread of life on Earth have all occurred in the geomagnetic field, and its extensive biological effects on living organisms have been documented. The charged characteristics of metal ions in biological fluids determine that they are affected by electromagnetic field forces, thus affecting life activities. Iron metabolism, as one of the important metal metabolic pathways, keeps iron absorption and excretion in a relatively balanced state, and this process is precisely and completely controlled. It is worth paying attention to how the iron metabolism process of living organisms is changed when exposed to electromagnetic fields. In this paper, the processes of iron absorption, storage and excretion in animals (mammals, fish, arthropods), plants and microorganisms exposed to electromagnetic field were summarized in detail as far as possible, in order to discover the regulation of iron metabolism by electromagnetic field. Studies and data on the effects of electromagnetic field exposure on iron metabolism in organisms show that exposure profiles vary widely across species and cell lines. This process involves a variety of factors, and the complexity of the results is not only related to the magnetic flux density/operating frequency/exposure time and the heterogeneity of the observed object. A systematic review of the biological regulation of iron metabolism by electromagnetic field exposure will not only contributes to a more comprehensive understanding of its biological effects and mechanism, but also is necessary to improve human awareness of the health related risks of electromagnetic field exposure.

Static magnetic field reduces cisplatin resistance via increasing apoptosis pathways and genotoxicity in cancer cell lines

Cisplatin is a chemotherapy drug widely used in cancer treatment. Alongside its clinical benefits, however, it may inflict intolerable toxicity and other adverse effects on healthy tissues. Due to the limitation of administering a high dose of cisplatin as well as cancer drug resistance, it is necessary to utilize new methods optimizing treatment modalities through both higher therapeutic efficacy and reduced administered doses of radiation and drugs. In this study, sensitive (A2780) and resistant (A2780CP) ovarian carcinoma cells underwent treatment with cisplatin + static magnetic field (SMF). First, the levels of genotoxicity after treatment were evaluated by Comet assay. Then, cell cycle analysis and apoptosis assay were conducted by a flow cytometer. Lastly, the expression levels of genes involved in apoptosis and cellular drug uptake were investigated by PCR. After treating different groups of cells for 24, 48, and 96 h, the co-treatment of SMF and cisplatin as a combination managed to increase the amount of DNA damage in both sensitive and resistant cell lines. A considerable increase in mortality of cells was also observed mostly in the form of apoptosis, which was caused by inhibition of the cell cycle. The combination also increased the expression levels of apoptotic genes, namely P53 and P21; however, it did not have much effect on the expression levels of BCL2. Besides, the levels of CTR1 gene expression increased significantly in the groups receiving the aforementioned combination. Our study suggests that the combination of cisplatin + SMF might have clinical potential which needs further investigations through future studies.

Polyethylenimine-based iron oxide nanoparticles enhance cisplatin toxicity in ovarian cancer cells in the presence of a static magnetic field

Background

Drug resistance in cancer cells is a major concern in chemotherapy. Cisplatin (CIS) is one of the most effective chemotherapeutics for ovarian cancer. Here, we investigated an experimental approach to increase CIS cytotoxicity and overcome cell resistance using nanoparticle-based combination treatments.

Methods

Polyethylenimine (PEI)-based magnetic iron oxide nanocomplexes were used for drug delivery in genetically matched CIS-resistant (A2780/CP) and -sensitive (A2780) ovarian cancer cells in the presence of a 20 mT static magnetic field. Magnetic nanoparticles (MNPs) were synthesized and bonded to PEI cationic polymers to form binary complexes (PM). The binding of CIS to the PM binary complexes resulted in the formation of ternary complexes PM/C (PEI-MNP/CIS) and PMC (PEI-MNP-CIS).

Results

CIS cytotoxicity increased at different concentrations of CIS and PEI in all binary and ternary delivery systems over time. Additionally, CIS induced cell cycle arrest in the S and G2/M phases and reactive oxygen species production in both cell lines. Ternary complexes were more effective than binary complexes at promoting apoptosis in the treated cells.

Conclusion

PEI-based magnetic nanocomplexes can be considered novel carriers for increasing CIS cytotoxicity and likely overcoming drug resistance of ovarian cancer cells.

Synergistic cytotoxic effects of an extremely low-frequency electromagnetic field with doxorubicin on MCF-7 cell line

Breast cancer is one of the leading causes of cancer deaths in women worldwide. Magnetic fields have shown anti-tumor effects in vitro and in vivo as a non-invasive therapy method that can affect cellular metabolism remotely. Doxorubicin (DOX) is one of the most commonly used drugs for treating breast cancer patients. It can be assumed that combining chemotherapy and magnetotherapy is one of the most effective treatments for breast cancer. This study aimed to investigate the potential cytotoxic effect of DOX at low concentrations in combination with extremely low-frequency electromagnetic fields (ELF-EMF; 50 Hz; 20 mT). The breast cancer cell line MCF-7 was examined for oxidative stress, cell cycle, and apoptosis. MCF-7 cells were treated with various concentrations of DOX as an apoptosis-inducing agent and ELF-EMF. Cytotoxicity was examined using the MTT colorimetric assay at 12, 24, and 48 h. Consequently, concentration- and time-dependent cytotoxicity was observed in MCF-7 cells for DOX within 24 h. The MTT assay results used showed that a 2 μM concentration of DOX reduced cell viability to 50% compared with control, and as well, the combination of ELF-EMF and DOX reduced cell viability to 50% compared with control at > 0.25 μM doses for 24 h. In MCF-7 cells, combining 0.25 μM DOX with ELF-EMF resulted in increased ROS levels and DOX-induced apoptosis. Flow cytometry analysis, on the other hand, revealed enhanced arrest of MCF-7 cells in the G0-G1 phase of the cell cycle, as well as inducing apoptotic cell death in MCF-7 cells, implying that the synergistic effects of 0.25 μM DOX and ELF-EMF may represent a novel and effective agent against breast cancer.

The effect of magnetic fields on tumor occurrence and progression: Recent advances

Malignancies are the leading human health threat worldwide. Despite rapidly developing treatments, poor prognosis and outcome are still common. Magnetic fields have shown good anti-tumoral effects both in vitro and in vivo, and represent a potential non-invasive treatment; however, the specific underlying molecular mechanisms remain unclear. We here review recent studies on magnetic fields and their effect on tumors at three different levels: organismal, cellular, and molecular. At the organismal level, magnetic fields suppress tumor angiogenesis, microcirculation, and enhance the immune response. At the cellular level, magnetic fields affect tumor cell growth and biological functions by affecting cell morphology, cell membrane structure, cell cycle, and mitochondrial function. At the molecular level, magnetic fields suppress tumors by interfering with DNA synthesis, reactive oxygen species level, second messenger molecule delivery, and orientation of epidermal growth factor receptors. At present, scientific experimental evidence is still lacking; therefore, systematic studies on the biological mechanisms involved are urgently needed for the future application of magnetic fields to tumor treatment.

Static magnetic field blocked alprazolam-induced behavior of Wistar rats in the elevated plus-maze test

Studies have shown that psychotropic drugs change rat behavior in the elevated plus-maze test (EPM). This study investigated whether static magnetic fields could alter alprazolam-induced rat behavior in the EPM. 66 male Wistar rats (270-300 g weight) were assigned to one of the following groups: Sham Magnetic + Saline (SMS), North Pole + Saline (NPS), South Pole + Saline (SPS), Sham magnetic + alprazolam (SMA), NP + alprazolam (NPA), and SP + alprazolam (SPA). After five days of static magnetic stimulation (3200 Gauss), they received alprazolam or saline (1 mg/kg), and their behavior was evaluated. Two-way ANOVA and Holm-Sidak post-hock were used, with a significant P value of <0.05. The SMA and NPA groups showed an increased number of entries and time in the open arms compared with the SMS group. SPA showed a decrease in these measures when compared to SMA [F(2,61) = 6.43 and F(2,61) = 3.72, respectively]. The SMA and NPA groups showed increased head dipping and end-arm activity compared with the SMS group. SPA showed a decrease in these measures when compared to SMA [F(2,61) = 3.37 and [F(2,61) = 4.72, respectively]. These results show that the south magnetic pole of a static magnetic field blocked the alprazolam effect in the space-time variables of the open arms and ethological anxiolytic-like behavior in the EPM.

Magnetic field effects in biology from the perspective of the radical pair mechanism

Hundreds of studies have found that weak magnetic fields can significantly influence various biological systems. However, the underlying mechanisms behind these phenomena remain elusive. Remarkably, the magnetic energies implicated in these effects are much smaller than thermal energies. Here, we review these observations, and we suggest an explanation based on the radical pair mechanism, which involves the quantum dynamics of the electron and nuclear spins of transient radical molecules. While the radical pair mechanism has been studied in detail in the context of avian magnetoreception, the studies reviewed here show that magnetosensitivity is widespread throughout biology. We review magnetic field effects on various physiological functions, discussing static, hypomagnetic and oscillating magnetic fields, as well as isotope effects. We then review the radical pair mechanism as a potential unifying model for the described magnetic field effects, and we discuss plausible candidate molecules for the radical pairs. We review recent studies proposing that the radical pair mechanism provides explanations for isotope effects in xenon anaesthesia and lithium treatment of hyperactivity, magnetic field effects on the circadian clock, and hypomagnetic field effects on neurogenesis and microtubule assembly. We conclude by discussing future lines of investigation in this exciting new area of quantum biology.

Static and Electromagnetic Fields Differently Affect Proliferation and Cell Death Through Acid Enhancement of ROS Generation in Mesenchymal Stem Cells

Magnetic fields remotely influence cellular homeostasis as a physical agent through the changes in cell physicochemical reactions. Magnetic fields affect cell fate, which may provide an important and interesting challenge in stem cell behaviors. Here, we investigated the effects of the static magnetic field (SMF, 20 mT) and electromagnetic field (EMF, 20 mT-50 Hz) on reactive oxygen species (ROS) production and the acidic pH conditions as stimuli to change cell cycle progression and cell death in mesenchymal stem cells. Results show that SMF, EMF, and their simultaneous (SMF+EMF) administration increase ROS and expression of nuclear factor erythroid 2-related factor 2 (Nrf2), superoxide dismutase 2 (SOD2), and glutathione-S-transferase (GST) as an antioxidant defense system. Besides, intracellular pH (pHi) decreases in presence of either EMF or SMF+EMF, but not SMF. Decreased ROS content using ascorbic acid in these treatments leads to increased pH compared to the magnetic field treatments alone. Furthermore, each magnetic field has different effects on the cellular process of stem cells, including cell cycle, apoptosis and necrosis. Moreover, treatment by SMF enhances the cell viability after 24 h, while EMF or SMF+EMF decreases it. These observations indicate that fluctuations of ROS generation and acid enhancement during SMF and EMF treatments may reveal their beneficial and adverse effects on the molecular and cellular mechanisms involved in the growth, death, and differentiation of stem cells.

Static Magnetic Fields Reduce Oxidative Stress to Improve Wound Healing and Alleviate Diabetic Complications

Although some studies have shown that some static magnetic fields (SMFs) can promote wound healing in diabetic mice, it is not clear whether the other diabetes complications, such as liver disease and diabetic nephropathy, can also be alleviated. Here, we constructed two simple magnetic plates using neodymium permanent magnets to examine the comprehensive effects of moderate SMFs on genetically obese leptin receptor-deficient db/db diabetic mice. We found that although the blood glucose was not obviously reduced by these two SMF settings, both of the glycated serum protein (GSP) and malondialdehyde (MDA) levels were significantly decreased (Cohen’s d = 2.57–3.04). Moreover, the wound healing, liver lipid accumulation, and renal defects were all significantly improved by SMF treatment (Cohen’s d = 0.91–2.05). Wound tissue examination showed obvious nuclear factor erythroid 2-related factor 2 (NRF2) level decrease (Cohen’s d = 2.49–5.40) and Ki-67 level increase (Cohen’s d = 2.30–3.40), indicating decreased oxidative stress and increased cell proliferation. In vitro cellular studies with fibroblast NIH3T3 cells showed that SMFs could reduce high glucose-induced NRF2 nucleus translocation (Cohen’s d = 0.87–1.15) and cellular reactive oxygen species (ROS) elevation (Cohen’s d = 0.92), indicating decreased oxidative stress. Consequently, high glucose-induced impairments in cell vitality, proliferation, and migration were all improved by SMF treatment. Therefore, our results demonstrate that these simple SMF devices could effectively reduce oxidative stress in diabetic mice and may provide a cost-effective physical therapy strategy to alleviate multiple diabetic complications in the future.

Moderate Static Magnet Fields Suppress Ovarian Cancer Metastasis via ROS-Mediated Oxidative Stress

Metastasis is the leading cause of cancer patient death, which is closely correlated with reactive oxygen species (ROS) levels. It is well known that the effects of ROS on tumors are diverse, depending on ROS concentration and cell type. We found that ovarian cancer cells have significantly lower levels of ROS than normal ovarian cells. Moreover, increased ROS levels in ovarian cancer cells can substantially inhibit their migration and invasion ability. Furthermore, the results show that moderate static magnetic field (SMF) can inhibit ovarian cancer cell migration, invasion, and stemness in a ROS-dependent manner. RNA sequencing results confirm that SMFs increased the oxidative stress level and reduced the stemness of ovarian cancer cells. Consistently, the expressions of stemness-related genes were significantly decreased, including hyaluronan receptor (CD44), SRY-box transcription factor 2 (Sox2), and cell myc proto-oncogene protein (C-myc). Furthermore, moderate SMFs provided by a superconducting magnet and permanent magnet have good biosafety and can both inhibit ovarian cancer metastasis in mice. Therefore, our study demonstrates the effects of SMFs on oxidative stress and metastasis in the ovarian cancer cells, which reveals the potential of applying SMF as a physical method in cancer therapy in the future.

Research progress in strategies to improve the efficacy and safety of doxorubicin for cancer chemotherapy

INTRODUCTION

DOX exerts strong anticancer activity and is commonly used to treat different cancers, including bone sarcomas, soft tissues, bladder, ovary, stomach, thyroid, breast, acute lymphoblastic leukemia, Hodgkin lymphoma, lung cancer, and myeloblastic leukemia. However, the cumulative doses of DOX above 550mg/m2 cause irreversible cardiotoxicity and other severe adverse effects. In this context, concerning DOX, several patents have been published in the last two decades. This activity highlights various aspects of DOX, such as registered patent analysis, pharmacological action, toxicityminimization, formulation development such as those approved by FDA, under clinical trials, and newly developed nano-delivery systems.

AREAS COVERED

This review analyzes the different aspects of DOX-based chemotherapeutics and the development of drug delivery systems in theliterature published from 2000 to early 2020.

EXPERT OPINION

DOX-based chemotherapy is still few steps away from being "perfect and safe" therapy. Certain severe systemic side effects are associated with DOX therapy. It is expected that, in the near future, DOX therapy can be much effective by selecting an ideal nanocarrier system, DOX conjugates, proper structural modifications, DOX-immunotherapy, and combination therapy. The advanced formulationsof DOX from the registered patents and recent research articles need clinical trials to bring safe treatment for cancer patients.

Effect of High Static Magnetic Field (2 T-12 T) Exposure on the Mineral Element Content in Mice

Relative stability of mineral elements in tissues is necessary for health. High static magnetic fields (HiSMFs) have been widely used in biomedical research and industry. However, the bioeffect of HiSMFs on animals is still unclear. In this study, we investigated the effects of HiSMF exposure on the levels of Mg, Fe, Zn, Ca, and Cu in the main organs of mice. The 8-week male C57BL/6 mice were treated by 2-4 T, 6-8 T, 10-12 T HiSMFs for 28 days. The mass fractions of Mg, Fe, Zn, Ca, and Cu in the liver, brain, kidney, and heart in mice were respectively measured by atomic absorption spectroscopy, and used to evaluate mineral element content in tissues. The 2-4 T HiSMF exposure has increased the Mg, Fe, and Ca content in the kidney, as well as the Zn content in the brain. The 6-8 T HiSMF exposure has increased the Zn level in the liver; Mg, Fe, and Ca levels in the kidney; and Fe level in the heart, while the Zn in the kidney, and Zn and Ca in the heart was decreased by 6-8 T HiSMF exposure. For the 10-12 T HiSMF exposure, the Mg in the kidney, the Fe in the liver and kidney, and Cu in the brain have been increased significantly. However, the Zn in the kidney and the Ca in the brain and the heart were reduced by 10-12 T HiSMF exposure. The HiSMF exposure for 28 days can alter the Mg, Fe, Zn, Ca, and Cu content in mice, and change with the different magnetic flux density of HiSMFs (2-4 T, 6-8 T, 10-12 T), elements, and organ types.

The impact of the co-exposure of melanoma cells to chlorogenic acid and a moderate-strength static magnetic field

A static magnetic field (SMF) or the bioactive compounds that are found in foods are potential agents that can be used to support cancer therapy. Therefore, the aim of our study was to assess the impact of the SMF that are induced by neodymium magnets on the culture growth and antioxidant status of melanoma cells that had been treated with chlorogenic acid (CGA). The melanoma cells, the control and those that had been treated with CGA, were put in special magnetic test chambers that generated a 0.7 T magnetic field. The mRNA levels of the antioxidant enzymes were analyzed using RT-qPCR. The activity of SOD, GPx, and CAT was measured in the cell lysates. While the expression and activity of the antioxidant enzymes was inhibited relative to the untreated cells as a result of the CGA treatment (1 mmol/L), it was not after the CGA treatment in combination with an SMF. The demonstrated cytotoxicity of CGA (1 mmol/L) and its inhibition of the antioxidant enzymes suggests the usefulness of phenolic compounds as a supporting pharmacological treatment for melanoma. PRACTICAL APPLICATIONS: Phenolic acids and their derivatives, which are the bioactive components of the human diet, are signal molecules that transfer information from the external environment that affects the level of gene expression in cells. This study suggests the usefulness of phenolic compounds as a supporting pharmacological treatment for melanoma and seems to be important for the development of experimental oncology.

Melatonin and doxorubicin co-delivered via a functionalized graphene-dendrimeric system enhances apoptosis of osteosarcoma cells

A functionalized graphene-dendrimeric system was designed via Fe₃O₄ nanoparticle (NP) as a magnetic nanocarrier for co-delivery of doxorubicin (DOX) and melatonin (MLT). Accordingly, β-Cyclodextrin (β-CD) was modified by creating amine functional groups. The modified β-CD was grafted with Graphene oxide (GO), and the resulting platform gain many functional groups, including the hydroxyl (-OH), carboxylic acid (-COOH), and amine functional groups (-NH2). Finally, magnetic NPs were synthesized on the prepared platform to efficiently controlling and targeting drugs to tumor sites. The human osteosarcoma cell lines including Saos-2 and MG-63, as well as Human Bone Marrow Mesenchymal Stem Cells (hBM-MSC) line, were used to determine the in vitro biological effects of the functionalized graphene-dendrimeric system. The magnetic nanocarrier has encapsulation efficiency (EE) values of 99.92% for DOX and 21.5% for MLT. The biocompatibility tests of the nanocarrier revealed that the magnetic nanocarrier was appropriate as a drug carrier. Co-delivery of DOX and MLT with an efficiently anticancer performance was also was confirmed by cellular uptake, 4',6-diamidino-2-phenylindole (DAPI) staining, and apoptosis analysis in comparison with free DOX and MLT. Moreover, there was a synergy in the antitumor effect when MLT was combined with DOX, especially in the nano-formulation form, which may be due to the down-regulation of X-linked Inhibitor of Apoptosis (XIAP), survivin, and human telomerase catalytic subunit (hTERT) (p < 0.0001). Overall, the result of our study suggests that the designed carrier is a promising nanocarrier for targeted co-delivery of DOX and MLT with improved anticancer efficacy in cancer cells and thus reduced toxicity in normal cells.

Targeting non-apoptotic cell death in cancer treatment by nanomaterials: Recent advances and future outlook

Many tumors develop resistance to most of the apoptosis-based cancer therapies. In this sense targeting non-apoptotic forms of cell death including necroptosis, autophagy and ferroptosis may have therapeutic benefits in apoptosis-defective cancer cells. Nanomaterials have shown great advantages in cancer treatment owing to their unique characteristics. Besides, the capability of nanomaterials to induce different forms of cell death has gained widespread attention in cancer treatment. Reports in this field reflect the therapeutic potential of necroptotic cell death induced by nanomaterials in cancer. Also, autophagic cell death induced by nanomaterials alone and as a part of chemo-, radio- and photothermal therapy holds great promise as anticancer therapeutic option. Besides, ferroptosis induction by iron-based nanomaterials in drug delivery, immunotherapy, hyperthermia and imaging systems shows promising results in malignancies. Hence, this review is devoted to the latest efforts and the challenges in this field of research and its clinical merits.

Induction of apoptosis and ferroptosis by a tumor suppressing magnetic field through ROS-mediated DNA damage

Magnetic field (MF) is being used in antitumor treatment; however, the underlying biological mechanisms remain unclear. In this study, the potency and mechanism of a previously published tumor suppressing MF exposure protocol were further investigated. This protocol, characterized as a 50 Hz electromagnetic field modulated by static MF with time-average intensity of 5.1 mT, when applied for 2 h daily for over 3 consecutive days, selectively inhibited the growth of a broad spectrum of tumor cell lines including lung cancer, gastric cancer, pancreatic cancer and nephroblastoma. The level of intracellular reactive oxygen species (ROS) increased shortly after field exposure and persisted. Subsequently, pronounced DNA damage and activation of DNA repair pathways were identified both in vitro and in vivo. Furthermore, use of free radical scavenger alleviated DNA damage and partially reduced cell death. Finally, this field was found to inhibit cell proliferation, and simultaneously induced two types of programmed cell death, apoptosis and ferroptosis. In conclusion, this tumor suppressing MF could determine cell fate through ROS-induced DNA damage, inducing oxidative stress and activation of the DNA damage repair pathways, eventually lead to apoptosis and ferroptosis, as well as inhibition of tumor growth.

Aptamer-Based Fluorescent Biosensing of Adenosine Triphosphate and Cytochrome c via Aggregation-Induced Emission Enhancement on Novel Label-Free DNA-Capped Silver Nanoclusters/Graphene Oxide Nanohybrids

Four fluorescent DNA-stabilized fluorescent silver nanoclusters (DNA-AgNCs) were designed and synthesized with differences in lengths of cytosine-rich DNA strand (as the stabilizing agent) and target-specific strand DNA aptamers for adenosine triphosphate (ATP) and cytochrome c (Cyt c). After their nanohybrid formation with graphene oxide (GO), it was unexpectedly found that, depending on the composition of the base and length of the strand DNA aptamer, the fluorescence intensity of three of the nanohybrids significantly enhanced. Our experimental observations and quantum mechanical calculations provided an insight into the mechanisms underlying the behavior of DNA-AgNCs/GO nanohybrids. The enhanced fluorescence was found to be attributed to the aggregation-induced emission enhancement (AIE) characteristic of the DNA-AgNCs adsorbed on the GO surface, as confirmed evidently by both fluorescence and transmission electron microscopies. The AIE is a result of hardness and oxidation properties of GO, which lead to enhanced argenophilic interaction and thus to increased Ag(I)-DNA complex shell aggregation. Consequently, two of the DNA-AgNCs/GO nanohybrids were successfully extended to construct highly selective, sensitive, label-free, and simple aptasensors for biosensing of ATP (LOD = 0.42 nM) and Cyt c (LOD = 2.3 nM) in lysed Escherichia coli DH5 α cells and mouse embryonic stem cells, respectively. These fundamental findings are expected to significantly influence the designing and engineering of new AgNCs/GO-based AIE biosensors.

Exposure to Static and Extremely-Low Frequency Electromagnetic Fields and Cellular Free Radicals

This paper summarizes studies on changes in cellular free radical activities from exposure to static and extremely-low frequency (ELF) electromagnetic fields (EMF), particularly magnetic fields. Changes in free radical activities, including levels of cellular reactive oxygen (ROS)/nitrogen (RNS) species and endogenous antioxidant enzymes and compounds that maintain physiological free radical concentrations in cells, is one of the most consistent effects of EMF exposure. These changes have been reported to affect many physiological functions such as DNA damage; immune response; inflammatory response; cell proliferation and differentiation; wound healing; neural electrical activities; and behavior. An important consideration is the effects of EMF-induced changes in free radicals on cell proliferation and differentiation. These cellular processes could affect cancer development and proper growth and development in organisms. On the other hand, they could cause selective killing of cancer cells, for instance, via the generation of the highly cytotoxic hydroxyl free radical by the Fenton Reaction. This provides a possibility of using these electromagnetic fields as a non-invasive and low side-effect cancer therapy. Static- and ELF-EMF probably play important roles in the evolution of living organisms. They are cues used in many critical survival functions, such as foraging, migration, and reproduction. Living organisms can detect and respond immediately to low environmental levels of these fields. Free radical processes are involved in some of these mechanisms. At this time, there is no credible hypothesis or mechanism that can adequately explain all the observed effects of static- and ELF-EMF on free radical processes. We are actually at the impasse that there are more questions than answers.

Combination of static magnetic field and cisplatin in order to reduce drug resistance in cancer cell lines

Purpose: In this study, the effects of different intensities of Static Magnetic Fields (SMFs) (10, 15 and 25 mT) and different concentrations of cisplatin drug were investigated on the viability percent and IC₅₀ of the A2780 and A2780-CP cell lines at 24, 48 and 96 h to show useful potential of SMF as a physical agent to enhance the effectiveness of common therapeutic approaches and decrease of drug resistance to cisplatin anticancer drug. Materials and methods: Magnetic field exposure was performed using a locally designed generator. The cell viability percent, IC₅₀ and cisplatin uptake in treated cells were evaluated by MTT assay and inductively coupled plasma (ICP), respectively. Results: Increasing of concentration and time of cisplatin drug showed a noticeable decrease in viability percent in sensitive and resistant cell lines compared with control group. These decreases were more significant in resistant cells compared with sensitive cells. The obtained IC₅₀ values for resistant were greater than the values obtained for A2780 cells. ICP analysis demonstrated an increased uptake of cisplatin after treatment for 48 and 96 h relative to untreated groups in both resistant and sensitive cells. Conclusion: Results showed that A2780 cells were more sensitive to cisplatin than A2780-CP. Studies have shown that SMF can increase the effect of cisplatin on cell viability percent and decrease the resistance of A2780-CP cells by producing large, verruca shaped structures at the surface of the cell membrane.

Iron and magnetic: new research direction of the ferroptosis-based cancer therapy

Ferroptosis is an iron depend cell death which caused by lipid peroxidation. Abnormal iron metabolism and high intracellular iron content are the characteristics of most cancer cells. Iron is a promoter of cell growth and proliferation. However, iron also could take part in Fenton reaction to produce reactive oxygen species (ROS). The intercellular ROS could induce lipid peroxidation, which is necessary for ferroptosis. Iron metabolism mainly includes three parts: iron uptake, storage and efflux. Therefore, iron metabolism-related genes could regulate intercellular iron content and status, which can be involved ferroptosis. In recent years, the application of nanoparticles in cancer therapy research has become more and more extensive. The iron-based nanoparticles (iron-based NPs) can release ferrous (Fe2+) or ferric (Fe3+) in acidic lysosomes and inducing ferroptosis. Magnetic field is widely used in the targeted concentration of iron-based NPs related disease therapy. Furthermore, multiple studies showed that magnetic fields can inhibit cancer cell proliferation by promoting intracellular ROS production. Herein, we focus on the relationship of between ferroptosis and iron metabolism in cancer cells, the application of nanoparticles and magnetic field in inducing ferroptosis of cancer cells, and trying to provide new ideas for cancer treatment research.