Effects of activation of AMPK on human breast cancer cell lines with different genetic backgrounds.

Breast cancer remains a therapeutic challenge, and this has intensified the search for new drug targets. The AMP-activated protein kinase (AMPK) signalling pathway is emerging as having potential for intervention. We assessed the possible different effects of AMPK action on breast cancer cells by studying their impact on proliferation, apoptosis and the mitochondrial membrane potential in three breast cancer cell lines (MCF-7, MDA-MB-231 and T47D) differing in their p53 and estrogen receptor (ER) status. Activation of AMPK by 5-aminoimidazole carboxamide ribonucleotide (AICAR) and phenformin elicited clear anti-proliferative effects in all breast cancer cell lines, but with differences in sensitivity. However, the anti-proliferative effects were accompanied by varying responses between the different cells, with a marked cell cycle arrest effect in T47D cells and an apoptotic effect in MCF-7 and MDA-MB-231 cells. The mitochondrial apoptotic pathway was potentially involved in all cell lines. These results suggest that AMPK potentially serves as a therapeutic target in breast cancer, but one which may be dependent on the genetic background of the cancer cells.