Study of genotoxic and cytotoxic effects induced in human fibroblasts by exposure to pulsed and

Abstract

Study of genotoxic and cytotoxic effects induced in human fibroblasts by exposure to pulsed and continuous 1.6 GHz radiofrequency Massaro L, De Sanctis S , Franchini V, Regalbuto E, Alfano G, Focaccetti C, Benvenuto M, Cifaldi L, Sgura A, Berardinelli F, Marinaccio J, Barbato F, Rossi E, Nardozi D, Masuelli L, Bei R, Lista F. Study of genotoxic and cytotoxic effects induced in human fibroblasts by exposure to pulsed and continuous 1.6 GHz radiofrequency. Frontiers in Public Health, Vol 12. 2024. doi: 10.3389/fpubh.2024.1419525. Abstract Background The widespread use of radiofrequency (RF) sources, ranging from household appliances to telecommunications devices and military equipment, raises concerns among people and regulatory agencies about the potential health risks of RF exposure. Consequently, several in vitro and in vivo studies have been done to investigate the biological effects, in particular non-thermal, of this non- ionizing radiation. To date, this issue is still being debated due to the controversial results that have been reported. Furthermore, the impact of different RF signal modulations on biological systems remains poorly investigated. The present in vitro study aims to evaluate the cytotoxicity and genotoxicity of continuous or pulsed 1.6 GHz RF in human dermal fibroblasts (HDF). Methods HDF cultures were exposed to continuous and pulsed 1.6 GHz RF, for 2 h, with Specific Absorption Rate (SAR) of 0.4 W/kg. The potential biological effects of 1.6 GHz RF on HDF were assessed with a multi-methodological approach, analyzing the effects on cell cycle, ultrastructure, protein expression, mitotic spindle, CREST stained micronuclei, chromosome segregation and γ-H2AX/53BP1 foci. Results 1.6 GHz RF exposure modified proteins expression and morphology of HDF. Specifically, the expression of different heat-shock proteins (HSP) (i.e., HSP-90, HSP-60, and HSP-25) and phospho-AKT were affected. In addition, both continuous and pulsed RF modified the cytoskeletal organization in HDF and increased the number of lysosomes, while the formation of autophagosomes was observed only after pulsed RF exposure. Mitotic spindle anomalies were also found after exposure. However, no significant effect was observed on cell cycle, chromosome segregation, CREST-stained micronuclei and γ- H2AX/53BP1 foci. Conclusion The results of the present study show the absence of genotoxic damage in 1.6 GHz RF exposed HDF and, although mitotic spindle alterations were observed, they did not have an aneugenic effect. On the other hand, changes in some proteins expression and cell ultrastructure in exposed HDF suggest that RF can potentially induce cell alterations at the morphological and molecular levels. Excerpt In this controversial scientific scenario, our results are in agreement with most in vitro findings on different cell models about the lack of genotoxic damage induced by RF, either clastogenic or aneugenic. Despite this, we find alterations of the mitotic spindle, with a significant increase in multipolar spindles following PW exposure and we also observed a tendency of RF to induce non-disjunction events with both signals. However, our study reveals an increase in these spindle abnormalities without a concomitant increase in MN-positive CREST, suggesting no aneuploidy effect probably due to spindle abnormalities reversion, as proposed by other authors (78). Nonetheless, this apparent discordant result requires further investigations. The reported observations indeed highlight the complexity of cellular response to RF and emphasize the need for further investigations to clarify the overall biological effects of 1.6 GHz PW and CW RF, given the widespread and constant public RF-EMF exposure, mostly due to mobile communication devices. Open access paper: frontiersin.org health/articles/10.3389/fpubh.2024.1419525

AI evidence extraction

Main findings

Exposure of human dermal fibroblasts to continuous or pulsed 1.6 GHz RF (2 h; SAR 0.4 W/kg) modified protein expression (including HSP-90, HSP-60, HSP-25 and phospho-AKT) and cell morphology/ultrastructure, including cytoskeletal changes and increased lysosomes; autophagosomes were observed only after pulsed exposure. Mitotic spindle anomalies were found after exposure, but no significant effects were observed on cell cycle, chromosome segregation, CREST-stained micronuclei, or γ-H2AX/53BP1 foci, and the authors conclude absence of genotoxic damage and no aneugenic effect.

Outcomes measured

• Cytotoxicity
• Genotoxicity
• Cell cycle
• Ultrastructure/morphology
• Protein expression (heat-shock proteins; phospho-AKT)
• Mitotic spindle anomalies
• CREST-stained micronuclei
• Chromosome segregation
• γ-H2AX/53BP1 foci
• Cytoskeletal organization
• Lysosomes
• Autophagosomes

Limitations

• In vitro study (human dermal fibroblast cultures)
• Exposure duration limited to 2 hours
• Sample size not reported in the provided abstract
• Findings described as requiring further investigations (e.g., apparent discordance between spindle abnormalities and lack of CREST-positive micronuclei)

{
    "study_type": "in_vitro",
    "exposure": {
        "band": "RF",
        "source": null,
        "frequency_mhz": 1600,
        "sar_wkg": 0.40000000000000002220446049250313080847263336181640625,
        "duration": "2 h"
    },
    "population": "Human dermal fibroblast (HDF) cultures",
    "sample_size": null,
    "outcomes": [
        "Cytotoxicity",
        "Genotoxicity",
        "Cell cycle",
        "Ultrastructure/morphology",
        "Protein expression (heat-shock proteins; phospho-AKT)",
        "Mitotic spindle anomalies",
        "CREST-stained micronuclei",
        "Chromosome segregation",
        "γ-H2AX/53BP1 foci",
        "Cytoskeletal organization",
        "Lysosomes",
        "Autophagosomes"
    ],
    "main_findings": "Exposure of human dermal fibroblasts to continuous or pulsed 1.6 GHz RF (2 h; SAR 0.4 W/kg) modified protein expression (including HSP-90, HSP-60, HSP-25 and phospho-AKT) and cell morphology/ultrastructure, including cytoskeletal changes and increased lysosomes; autophagosomes were observed only after pulsed exposure. Mitotic spindle anomalies were found after exposure, but no significant effects were observed on cell cycle, chromosome segregation, CREST-stained micronuclei, or γ-H2AX/53BP1 foci, and the authors conclude absence of genotoxic damage and no aneugenic effect.",
    "effect_direction": "mixed",
    "limitations": [
        "In vitro study (human dermal fibroblast cultures)",
        "Exposure duration limited to 2 hours",
        "Sample size not reported in the provided abstract",
        "Findings described as requiring further investigations (e.g., apparent discordance between spindle abnormalities and lack of CREST-positive micronuclei)"
    ],
    "evidence_strength": "low",
    "confidence": 0.85999999999999998667732370449812151491641998291015625,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "radiofrequency",
        "1.6 GHz",
        "pulsed",
        "continuous",
        "SAR 0.4 W/kg",
        "human dermal fibroblasts",
        "genotoxicity",
        "cytotoxicity",
        "micronuclei",
        "γ-H2AX",
        "53BP1",
        "mitotic spindle",
        "heat-shock proteins",
        "phospho-AKT",
        "autophagy",
        "ultrastructure"
    ],
    "suggested_hubs": []
}

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