Growth modification of human colon adenocarcinoma cells exposed to a low-frequency electromagnetic field.

The influence of variable low-intensity, low-frequency electromagnetic fields on culture cells is investigated. Human colon adenocarcinoma cells were exposed to a rectangular and variable magnetic field (1 and 25 Hz; 1.5 mT peak). Cultures were exposed to a dose for 15 and 360 minutes, and after 24 hours incubation, cell viability was measured with neutral red stain. The group treated for 15 minutes showed a statistically significant increase in cell growth with 1 Hz (p < 0.002) and 25 Hz (p < 0.003). In contrast, a significant decrease in cell growth was found in those cultures treated with 1 Hz for 360 minutes (p < 0.02). The effects reported could be influenced by the magnetic field frequency and the exposure time.

He-Ne laser has no effect on cell cycle phases of human colon adenocarcinoma cells.

The aim of this study is to investigate the effect of He-Ne continuous laser (12.6 mW, 632.8 nm), at low energy densities, on cell cycle synchronization of monolayer growing human colon adenocarcinoma cell line. The doubling time of cell culture was used as optimum time to verify laser effect. The monolayer cultures were exposed to single doses of different energy densities (0.042 J cm-2 to 1.68 J cm-2). The nuclear DNA content has been studied by flow cytometry to obtain the cell percentage in each cell cycle phase. Results show no effect of He-Ne laser irradiation on cell cycle short time synchronization under the previously mentioned conditions and cell type. Higher energy densities and multiple irradiations should be investigated.