Voltammetric behavior of the MCF-7 cell cytoplasm and the effect of taxol on voltammetric response.

The aims of this study were to find the electroactive species in the human breast cancer (MCF-7) cell cytoplasm causing a voltammetric response of the cells and to establish a simple and rapid measurement method to obtain strong and direct electrochemical responses objectively reflecting the cell viability. Ultrasonication was carried out for the electrochemical detection. The presence of guanine and xanthine in the MCF-7 cell eluent secreted by the living cells and in the MCF-7 cell cytoplasm was verified by HPLC assay with a DAD system and chemometric method. The concentrations of guanine and xanthine in the MCF-7 cell cytoplasm and the voltammetric response of the MCF-7 cell cytoplasm had higher levels than those of intact cell suspensions. Additionally, taxol caused a decrease of the voltammetric response of the cytoplasm and concentrations of xanthine and guanine in the cytoplasm. Therefore, the origin of the voltammetric response of the MCF-7 cytoplasm was driven by the alteration of the levels of xanthine and guanine, which were related to the cell viability. Thus, the voltammetric response of the ultrasonicated MCF-7 cell suspension could be used to monitor the MCF-7 cell growth and to evaluate the effectiveness of antitumor drugs on tumor suppression.