Send to

Choose Destination
Chemotherapy. 2004 Jun;50(2):55-62.

Mitochondria-targeting drug oligomycin blocked P-glycoprotein activity and triggered apoptosis in doxorubicin-resistant HepG2 cells.

Author information

Department of Biochemistry, The Chinese University of Hong Kong, Shatin, China.



Mitochondria are key regulators in apoptosis. This suggests that a mitochondrion can be a target for cancer treatment. To examine the feasibility of this approach, we investigated the effect of oligomycin on the induction of apoptosis in drug-resistant cells. As a mitochondrion-targeting agent, oligomycin inhibits mitochondrial F0F1-ATPase. Of 37,000 molecules tested against the 60 human cancer cell lines of the National Cancer Institute, oligomycin is among the top 0.1% most cell line selective agents.


Changes in the doxorubicin (Dox) accumulation and mitochondrial potential (Deltapsim) in human hepatocarcinoma HepG2 and its derivative R-HepG2 with Dox resistance were determined by flow cytometry. P-glycoprotein (Pgp) expression and release of cytochrome c from mitochondria were analyzed by Western blot. Cytotoxicity was examined by DNA fragmentation and the alamar blue assay.


R-HepG2 cells produced Pgp, showed drug resistance and accumulated less Dox when compared to their parent. In both cell lines, oligomycin depolarized Deltapsim, released cytochrome c and elicited DNA fragmentation. Moreover, oligomycin blocked Pgp activity and accumulated more Dox in R-HepG2. Combined treatment with Dox and oligomycin elicited more cell death.


Our results suggest that oligomycin could bypass Dox resistance and trigger apoptosis in R-HepG2 cells.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for S. Karger AG, Basel, Switzerland
Loading ...
Support Center