BACKGROUND AND PURPOSE: Metformin is commonly prescribed to treat type 2 diabetes, and has additional potential as a cancer prophylactic and therapeutic. Metformin activates AMPK that in turn can launch a p53-dependent metabolic checkpoint. Possible interactions between metformin and radiation are poorly understood. Since radiation-induced signaling also involves AMPK and p53, we investigated their importance in mediating responses to metformin and radiation. MATERIALS AND METHODS: A549 cells, HCT116 cells wildtype or knockout for p53 or MEFs wildtype or double knockout for AMPKα1 and α2 were irradiated in the presence or absence of metformin. The impact of metformin on oxygen consumption and proliferation rates was determined, as well as clonogenic radiation survival. RESULTS: Metformin resulted in moderate radiation protection in all cell lines, irrespective of AMPK and p53. Loss of AMPK sensitized cells to the anti-proliferative effects of metformin, while loss of p53 promoted both the growth inhibitory and toxic effects of metformin. Consequently, overall cell death after radiation was similar with and without metformin irrespective of AMPK or p53 genotype. CONCLUSIONS: The anti-proliferative activity of metformin may confer benefit in combination with radiotherapy, and this benefit is intensified upon loss of AMPK or p53 signaling.
BACKGROUND AND PURPOSE:Metformin is commonly prescribed to treat type 2 diabetes, and has additional potential as a cancer prophylactic and therapeutic. Metformin activates AMPK that in turn can launch a p53-dependent metabolic checkpoint. Possible interactions between metformin and radiation are poorly understood. Since radiation-induced signaling also involves AMPK and p53, we investigated their importance in mediating responses to metformin and radiation. MATERIALS AND METHODS: A549 cells, HCT116 cells wildtype or knockout for p53 or MEFs wildtype or double knockout for AMPKα1 and α2 were irradiated in the presence or absence of metformin. The impact of metformin on oxygen consumption and proliferation rates was determined, as well as clonogenic radiation survival. RESULTS:Metformin resulted in moderate radiation protection in all cell lines, irrespective of AMPK and p53. Loss of AMPK sensitized cells to the anti-proliferative effects of metformin, while loss of p53 promoted both the growth inhibitory and toxic effects of metformin. Consequently, overall cell death after radiation was similar with and without metformin irrespective of AMPK or p53 genotype. CONCLUSIONS: The anti-proliferative activity of metformin may confer benefit in combination with radiotherapy, and this benefit is intensified upon loss of AMPK or p53 signaling.
Authors: Jeffrey S Murley; Richard C Miller; Raziye Rana Senlik; Alfred W Rademaker; David J Grdina Journal: Int J Radiat Biol Date: 2017-03-28 Impact factor: 2.694
Authors: Fernando Mendes; Tiago Sales; Cátia Domingues; Susann Schugk; Ana Margarida Abrantes; Ana Cristina Gonçalves; Ricardo Teixo; Rita Silva; João Casalta-Lopes; Clara Rocha; Mafalda Laranjo; Paulo César Simões; Ana Bela Sarmento Ribeiro; Maria Filomena Botelho; Manuel Santos Rosa Journal: Med Oncol Date: 2015-11-18 Impact factor: 3.064