Cellular cytotoxicity assays determined that MCF7VP cells are more resistant to etoposide than the parental MCF7 cells.

<p>Curve fitting of cellular cytotoxicity data with GraphPad prism. (MCF7VP- red squares and MCF7- blue circles). The dotted line represents the actual curve and the solid line depicts the fitted curve. The assay was carried out using 10,000 cells per well of a 96 well plate and 100 µl of various concentrations (0–100 µM) of etoposide (the graph depicts log concentrations of etoposide).