Non ionising radiation as a non chemical strategy in regenerative medicine: Ca(2+)-ICR "In Vitro" effect on neuronal differentiation and tumorigenicity modulation in NT2 cells

• Published in: PloS one Vol. 8; no. 4; p. e61535
• Main Authors: Ledda, Mario, Megiorni, Francesca, Pozzi, Deleana, Giuliani, Livio, D'Emilia, Enrico, Piccirillo, Sara, Mattei, Cristiana, Grimaldi, Settimio, Lisi, Antonella
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science (PLoS) 2013
• Subjects: Biomarkers - metabolism; Calcium - chemistry; Cations, Divalent; Cell Differentiation - drug effects; Cell Differentiation - radiation effects; Cell Line; Electromagnetic Fields; Electromagnetic Radiation; Embryonal Carcinoma Stem Cells - drug effects; Embryonal Carcinoma Stem Cells - metabolism; Embryonal Carcinoma Stem Cells - pathology; Embryonal Carcinoma Stem Cells - radiation effects; Fibroblast Growth Factor 4 - genetics; Fibroblast Growth Factor 4 - metabolism; Gene Expression Regulation - drug effects; Gene Expression Regulation - radiation effects; GPI-Linked Proteins - genetics; GPI-Linked Proteins - metabolism; Humans; Intercellular Signaling Peptides and Proteins - genetics; Intercellular Signaling Peptides and Proteins - metabolism; Neoplasm Proteins - genetics; Neoplasm Proteins - metabolism; Neurons - cytology; Neurons - metabolism; Transforming Growth Factor alpha - genetics; Transforming Growth Factor alpha - metabolism; Tretinoin - pharmacology
• ISSN: 1932-6203
• DOI: 10.1371/journal.pone.0061535

In regenerative medicine finding a new method for cell differentiation without pharmacological treatment or gene modification and minimal cell manipulation is a challenging goal. In this work we reported a neuronal induced differentiation and consequent reduction of tumorigenicity in NT2 human pluripotent embryonal carcinoma cells exposed to an extremely low frequency electromagnetic field (ELF-EMF), matching the cyclotron frequency corresponding to the charge/mass ratio of calcium ion (Ca(2+)-ICR). These cells, capable of differentiating into post-mitotic neurons following treatment with Retinoic Acid (RA), were placed in a solenoid and exposed for 5 weeks to Ca(2+)-ICR. The solenoid was installed in a μ-metal shielded room to avoid the effect of the geomagnetic field and obtained totally controlled and reproducible conditions. Contrast microscopy analysis reveled, in the NT2 exposed cells, an important change in shape and morphology with the outgrowth of neuritic-like structures together with a lower proliferation rate and metabolic activity alike those found in the RA treated cells. A significant up-regulation of early and late neuronal differentiation markers and a significant down-regulation of the transforming growth factor-α (TGF-α) and the fibroblast growth factor-4 (FGF-4) were also observed in the exposed cells. The decreased protein expression of the transforming gene Cripto-1 and the reduced capability of the exposed NT2 cells to form colonies in soft agar supported these last results. In conclusion, our findings demonstrate that the Ca(2+)-ICR frequency is able to induce differentiation and reduction of tumorigenicity in NT2 exposed cells suggesting a new potential therapeutic use in regenerative medicine.