Figure 2.

Effect of anticancer agents on mtDNA copy number. (a) HCT116 cells were treated with etoposide (Etop; 10 μM for 24 h), taxol (TX; 30 nM for 24 h), apicidin (Apic; 1 μM for 24 h), sorafenib (Sor; 20 μM for 24 h), staurosporine (STS; 500 nM for 3 h), and thapsigargin (Thaps; 5 μM for 24). (b) HCT116 cells were pretreated with OXPHOS complex inhibitors for 2 h followed by addition of etoposide (Etop; 10 μM for 24 h). Etoposide-induced mtDNA levels were evaluated on inhibition of complex-I by rotenone (Rot; 10 μM), complex-III by antimycin A (AA; 10 μM), and complex V by oligomycin (Oligo; 10 μM). (c) The level of mtDNA in the HCT116 Bax^−/−, HCT116 p53^−/−, and HCT116 p21^−/− cells treated with etoposide (Etop; 10 μM for 24 h). Relative mtDNA level following exposure to various agents was measured by estimation of COX-2 and ATPase genes normalized to nDNA. Data are mean±S.D., n=4. *P≤0.05