(A) Cas IIgly (5 μM, 6 h) induced mitochondrial DNA (mtDNA) damage in A549 cells, as detected by amplification efficiency assay. Bars with different letters are statistically different from one another (n = 3, P < 0.05). (B) Cas IIgly (5 μM, 12 h) produced an imbalance in the expression of complex I (39 Kd) versus complex II (70 Kd) of the mitochondrial respiratory chain in A549 cells, as shown by immunoblotting. Each figure was representative of three samples and the experiment repeated once.