Fig. 3

Positive correlation between the baseline intracellular ROS level and drug resistance against CDDP (a) and DQA (b). Positive correlations between the relative content of mtDNA and the baseline intracellular ROS level (c), mitochondrial superoxide level (d), CDDP IC50s (e), DQA IC50s (f). Positive correlations between the numbers of non-synonymous variations in the complexes I & III coding regions and baseline ROS levels (g), mitochondrial superoxide levels (h), CDDP IC50s (i), DQA IC50s (j). Data points representing the cell lines are in the sequence of PNT-2, Ishikawa, MDA-MB-231, PC-3 and Caco-2. r and p and values were calculated using the Pearson correlation coefficient method; *p < 0.05 and **p < 0.01