Constructal thermodynamics combined with infrared experiments to evaluate temperature differences in cells.

The aim of this work was to evaluate differences in energy flows between normal and immortalized cells when these distinct biological systems are exposed to environmental stimulation. These differences were considered using a constructal thermodynamic approach, and were subsequently verified experimentally. The application of constructal law to cell analysis led to the conclusion that temperature differences between cells with distinct behaviour can be amplified by interaction between cells and external fields. Experimental validation of the principle was carried out on two cellular models exposed to electromagnetic fields. By infrared thermography we were able to assess small changes in heat dissipation measured as a variation in cell internal energy. The experimental data thus obtained are in agreement with the theoretical calculation, because they show a different thermal dispersion pattern when normal and immortalized cells are exposed to electromagnetic fields. By using two methods that support and validate each other, we have demonstrated that the cell/environment interaction can be exploited to enhance cell behavior differences, in particular heat dissipation. We propose infrared thermography as a technique effective in discriminating distinct patterns of thermal dispersion and therefore able to distinguish a normal phenotype from a transformed one.

Extremely low frequency electromagnetic fields affect proliferation and mitochondrial activity of human cancer cell lines.

PURPOSE: To date, the effects of electromagnetic fields on cell metabolism have been overlooked. The objective of the present study was to investigate the influence of extremely low frequency electromagnetic fields (ELF-EMF) over mitochondrial metabolism and the consequent impact on cancer cell growth. MATERIALS AND METHODS: The effects of ELF-EMF on cancer growth were investigated in several human cancer cell lines by crystal violet assay. The modulation of mitochondrial activity was assessed by cytofluorimetric evaluation of membrane potential and by real-time quantification of mitochondrial transcription. Moreover the expression of several mitochondrial proteins and their levels in the organelle were evaluated. RESULTS: The long-term exposure to ELF-EMF reduced the proliferation of several cancer cell lines and the effect was associated to an increased mitochondrial activity without evident changes in ATP levels. The results of our experiments excluded a transcriptional modulation of mitochondrial respiratory complexes, rather suggesting that ELF-EMF increased the energy demand. The altered mitochondrial metabolism led to changes in mitochondrial protein profile. In fact we found a downregulated expression of mitochondrial phospho-ERK, p53 and cytochrome c. CONCLUSION: The results of the present study indicate that ELF-EMF can negatively modulate cancer cell growth increasing respiratory activity of cells and altering mitochondrial protein expression.