Transmission electron microscopy study of the effects produced by wide-band low-power millimeter waves on MCF-7 human breast cancer cells in culture.

Our previous work showed that low-power wide-band millimeter waves (MMW) inhibit the growth of the MCF-7 human breast carcinoma cell line, also causing a marked reduction of the density of microvilli at the apical membrane of the MCF-7 cells, as revealed by scanning electron microscopy. The aim of the present work was to investigate the ultrastructural changes induced by such electromagnetic radiations on this cell line. A transmission electron microscopy study was performed on MCF-7 cells irradiated under the same experimental conditions previously adopted. Transmission electron microscopy analysis revealed several ultrastructural features of the MMW-irradiated cells pertinent to cells subjected to sublethal injury. The antiproliferative effect of the millimeter radiation was confirmed. MMW, in the 52-78 GHz frequency range, act as stress factor on the cells that survive in a non-steady low-mitogenetic metabolic state.