Trillo MA, Cid MA, Martínez MA, Page JE, Esteban J, Ubeda A. Cytostatic response of NB69 cells to weak pulse-modulated 2.2 GHz radar-like signals. Bioelectromagnetics. Jan 28, 2011. Ahead of print.
There is a growing exposure of the public and workers to RF signals from a large variety of sources especially from repeated and chronic exposure to RF fields. This has created an interest in better understanding the potential biological responses to subthermal levels of RF exposure that could be found at residential or occupational environments. Previous epidemiological studies addressing health related endpoints have generated conflicting data regarding possible adverse effects of the chronic. However, other studies have reported changes in DNA synthesis, cell cycle control and/or apoptosis. Other studies found that RF radiation to affect biochemical and molecular mechanisms.
Objective of the study
To investigate the response of two human cancer cell lines to a 24-h treatment with a 2.2-GHz, pulse-modulated (5 ms pulse duration, 100 Hz repetition rate) radar-like signal. The study addresses the hypothesis that low-level RF signals could influence cancer progression by enhancing or accelerating cell proliferation in human cancer cells.
The system was designed for evaluation of the cellular response to pulse-modulated, radar-like signals, which are characterized by high RF instantaneous amplitudes with very low average power. The human hepatocarcinoma cell line HepG2 and The human neuroblastoma cell line NB69 were used in the exposure experiments. In all experimental runs, two cell culture groups composed of 8 Petri dishes each were incubated simultaneously inside the waveguides.
Results show that while the hepatocarcinoma HepG2 cell line does not seem to be sensitive to the RF treatment, the neuroblastoma NB69 cell line responded with a significant decrease in total cell number, together with increased rates of cells in phases G0/G1 and G2/M of the cell cycle. These responses were accompanied with a modest but statistically significant decrease in the percent of viable cells, and the fraction in the sub G0/G1 population.
The results suggested that RF fields can exert an effect on mechanisms intervening on survival of neuroblastoma cells. As a whole, these results are not supportive of the hypothesis that RF signals at low doses can exert carcinogenic effects by increasing cell proliferation. Additional research testing different power densities and other signal parameter combinations is needed in order to identify the dose threshold and to characterize the dose-response function for the observed effects.