Effects Induced by a Weak Static Magnetic Field of Different Intensities on HT-1080 Fibrosarcoma Cells

Abstract

Effects Induced by a Weak Static Magnetic Field of Different Intensities on HT-1080 Fibrosarcoma Cells Hakki Gurhan, Rodolfo Bruzon, Sahithi Kandala, Ben Greenebaum, Frank Barnes. Effects Induced by a Weak Static Magnetic Field of Different Intensities on HT-1080 Fibrosarcoma Cells. Bioelectromagnetics. 2021 Mar 18. doi: 10.1002/bem.22332. Abstract In this study, we investigated the effects of weak static magnetic fields (SMFs) on HT-1080 human fibrosarcoma cells. Exposures to SMFs for four consecutive days were varied from 0.5 to 600 µT for treated units, while exposures to control units were held at 45 µT. Growth rates were measured by comparing cell counts, whereas membrane potentials, mitochondrial calcium, mitochondrial superoxide (O2 - ), nitric oxide (NO), hydrogen peroxide (H2 O2 ), intercellular pH, and oxidative stress were measured by using fluorescent dyes. The relative cell growth rates vary with the angle of the SMFs. Increases in the magnitude of the SMFs increased concentrations of mitochondrial calcium and membrane potential and decreased intracellular pH. H2 O2 , an important reactive oxygen species (ROS), increases at 100 and 200 µT, decreases at 300 and 400 µT and increases again at 500 and 600 µT. Overall, oxidative stress increases slightly with increasing SMFs, while superoxide and NO concentrations decrease. These results indicate that weak SMFs can accelerate and inhibit cell growth rates and induce alterations in ROS. Changes in ROS and oxidative stress are important for various cell functions. Calcium influx into mitochondria was one of the initial steps into the corresponding changes. pubmed.ncbi.nlm.nih.gov Excerpts In the present study, we looked at mitochondrial ROS generation as an important source for ROS signaling and concentrated our attention on the initial parts of the mitochondrial signaling pathways. Mitochondrial superoxide, H2O2, and NO are considered important intra-mitochondrial signaling molecules. In our experiments, ROS responses to the SMF were more complex. Changes in H2O2 are not linearly correlated with cell growth. This might be due to increases in antioxidant concentrations [Rosenspire et al., 2005]. Decreases in H2O2 correspond to where we observed the highest increase in cell growth rates. There are various studies showing that low levels of H2O2 can initiate cell proliferation [Antunes and Brito, 2017; Sies, 2017]. The mitochondrial superoxide and the NO tend to decrease with the increase in MF. The mitochondrial superoxide decreased with respect to the control for all SMF values, being highly significant for 200 and 400 µT, and the NO decreased with respect to the control for 0.5, 100, 400, and 600 µT. H2O2 and oxidative stress tend to increase with the increase in SMF. In both parameters, a highly significant increase was observed for 100 and 200 µT. The importance of these results is that variations of background MFs can both increase and decrease cell growth rates and corresponding concentrations of ROS and other signaling molecules. These observed changes are significant as different concentration levels of ROS could have beneficial or adverse effects on biology. In conclusion, the basic effect observed here is that changes in SMFs create a change in the growth rate of the cells and changes in some important molecular concentrations on both sides of the cell and mitochondrial membrane. Though the growth rate is one of the parameters that we have studied, the changes in the signaling molecules and other cell parameters might cause long-term effects in biological systems. An example of this is long-term changes in oxidative stress related to cancer and aging‐related diseases. Canceling out the earth′s MF substantially, down to 0.5 µT by Mu metal cages, not only gave us the capability to eliminate background noise but also allowed us to observe effects at a level much lower than the earth′s MF. Thus, in this study, we believe that measuring and controlling the SMFs and eliminating the effects of temperature and background noise in experiments are important for attempting to understand the effects of electromagnetic fields on biological systems. Additionally, we believe that the amplitude, angle of incidence, and length of the exposure can lead to variable results and need to be included in the description of experimental protocols [Barnes and Greenebaum, 2015]. Future work will include time-varying MFs, where we expect to see both electric and MF effects. Time-varying MFs induce electric fields; other data indicate that both electric and MFs can induce changes in cell growth rates and other biological parameters [Bingham, 1996]. More research work will be required to determine the mechanisms by which these two different fields modify the behavior of cells.

AI evidence extraction

Main findings

HT-1080 cells were exposed to weak static magnetic fields (0.5–600 µT) for four consecutive days (controls at 45 µT). Reported responses included angle-dependent changes in relative cell growth rate; with increasing field magnitude, mitochondrial calcium and membrane potential increased and intracellular pH decreased. H2O2 showed a non-linear pattern (increased at 100–200 µT, decreased at 300–400 µT, increased again at 500–600 µT); overall oxidative stress increased slightly with increasing SMF, while mitochondrial superoxide and NO tended to decrease.

Outcomes measured

• cell growth rate (cell counts)
• membrane potential
• mitochondrial calcium
• mitochondrial superoxide
• nitric oxide (NO)
• hydrogen peroxide (H2O2)
• intercellular pH
• oxidative stress

Limitations

• In vitro study in a single human fibrosarcoma cell line (HT-1080)
• Sample size not reported in the provided abstract
• Control condition used a background/static field of 45 µT rather than a true zero-field condition
• Multiple outcomes with non-linear and angle-dependent responses complicate interpretation

{
    "study_type": "in_vitro",
    "exposure": {
        "band": "static",
        "source": "other",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": "four consecutive days"
    },
    "population": "HT-1080 human fibrosarcoma cells",
    "sample_size": null,
    "outcomes": [
        "cell growth rate (cell counts)",
        "membrane potential",
        "mitochondrial calcium",
        "mitochondrial superoxide",
        "nitric oxide (NO)",
        "hydrogen peroxide (H2O2)",
        "intercellular pH",
        "oxidative stress"
    ],
    "main_findings": "HT-1080 cells were exposed to weak static magnetic fields (0.5–600 µT) for four consecutive days (controls at 45 µT). Reported responses included angle-dependent changes in relative cell growth rate; with increasing field magnitude, mitochondrial calcium and membrane potential increased and intracellular pH decreased. H2O2 showed a non-linear pattern (increased at 100–200 µT, decreased at 300–400 µT, increased again at 500–600 µT); overall oxidative stress increased slightly with increasing SMF, while mitochondrial superoxide and NO tended to decrease.",
    "effect_direction": "mixed",
    "limitations": [
        "In vitro study in a single human fibrosarcoma cell line (HT-1080)",
        "Sample size not reported in the provided abstract",
        "Control condition used a background/static field of 45 µT rather than a true zero-field condition",
        "Multiple outcomes with non-linear and angle-dependent responses complicate interpretation"
    ],
    "evidence_strength": "low",
    "confidence": 0.7800000000000000266453525910037569701671600341796875,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "static magnetic field",
        "SMF",
        "microtesla",
        "HT-1080",
        "fibrosarcoma",
        "cell growth",
        "reactive oxygen species",
        "oxidative stress",
        "mitochondrial calcium",
        "membrane potential",
        "hydrogen peroxide",
        "superoxide",
        "nitric oxide",
        "pH"
    ],
    "suggested_hubs": []
}

Comments

Log in to comment.

No comments yet.