Monitoring proliferative activities of hormone-like odorants in human breast cancer cells by gene transcription profiling and electrical impedance spectroscopy.

The human estrogen receptor alpha (ERα) mediates the proliferative action of hormones in breast cancer cells by regulating the expression of target genes to control cellular functions. Current methodologies do not permit a real-time assessment of these processes in living cells. We overcome this limitation using electrical cell-substrate impedance sensing for measuring ERα-regulated signaling processes indicative of the onset of cell proliferation to target them for compound screenings. We report that hormone like odorants regulate, similarly as natural estrogen, ERα-mediated gene expression involved in mitogenic and developmental processes in MCF7 breast cancer cells. An odorant concentration-dependent switch in cell responses was detectable already 10-15 h post-stimulation, providing rapid quantification of hormonal activity before cell division occurred. Though ERα exhibits complex regulatory roles our non-invasive approach captures its activity for accelerated screenings of compounds promoting breast cancer cell proliferation expanding the analysis of ERα signaling networks.