Figure 6From: Changes in P-glycoprotein activity are mediated by the growth of a tumour cell line as multicellular spheroidsCytotoxicity of doxorubicin (a), etoposide (b) and methotrexate (c) in monolayers or multicellular spheroids from PSC-1 (P-gpneg) clone cells in comparison to the parental INER-51 cell line. Cytotoxicity was measurement by the MTT colorimetric assay and expressed as percent growth inhibition in comparison with the untreated tumour cells. Each point represents the mean of at least 3 independent experiments and error bars are the standard error of the meanBack to article page