title: Combined inhibition of glycolysis and AMPK induces synergistic breast cancer cell killing.
abstract: Targeting glycolysis for cancer treatment has been investigated as a therapeutic method but has not offered a feasible chemotherapeutic strategy. Our aim was to examine whether AMP-activated protein kinase (AMPK), a conditional oncogene, rescues the energetic stress and cytotoxicity induced by 2-deoxyglucose (2-DG), a glycolytic inhibitor, and the related mechanisms. Luciferin/luciferase adenosine triphosphate (ATP) determination, Western analysis, qRT-PCR analyses, MTT growth assay, clonogenic assay, and statistical analysis were performed in this study. 2-DG decreased ATP levels and subsequently activated AMPK, which contribute to intracellular ATP recovery in MCF-7 cells thus exhibiting no apparent cytotoxicity. Compound C, an AMPK inhibitor, further potentiates 2-DG-induced decrease in ATP levels and inhibits their recovery. 2-DG, via AMPK activation, stimulated cAMP response element-binding protein (CREB) phosphorylation and activity and promoted nuclear peroxisome proliferator-activated receptor gamma coactivator-1-beta (PGC-1β) and estrogen-related receptor α (ERRα) protein expression, leading to augmented mitochondrial biogenesis and expression of fatty acid oxidation (FAO) genes including PPARα, MCAD, CPT1C, and ACO. This metabolic adaptation elicited by AMPK counteracts the ATP-depleting and cancer cell-killing effect of 2-DG. However, 2-DG in combination with AMPK antagonists or small interfering RNA caused a dramatic increase in cytotoxicity in MCF-7 but not in MCF-10A cells. Similarly, when combined with inhibition of CREB/PGC-1β/ERRα pathway, 2-DG saliently suppressed mitochondrial biogenesis and the expression of FAO genes, depleted ATP production, and enhanced cytotoxicity in cancer cells. Collectively, the combination of 2-DG and AMPK inhibition synergistically enhanced the cytotoxic potential in breast cancer cells with a relative nontoxicity to normal cells and may offer a promising, safe, and effective breast cancer therapeutic strategy.
authors.affiliation: Division of Cancer Research and Training, Charles R. Drew University of Medicine and Science, Los Angeles, CA, 90059, USA, yongwu@cdrewu.edu.
authors.forename: Yong
authors.initials: Y
authors.lastname: Wu
authors.forename: Marianna
authors.initials: M
authors.lastname: Sarkissyan
authors.forename: Eva
authors.initials: E
authors.lastname: Mcghee
authors.forename: Sangkyu
authors.initials: S
authors.lastname: Lee
authors.forename: Jaydutt V
authors.initials: JV
authors.lastname: Vadgama
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D003847:Deoxyglucose / Q000378:metabolism / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006019:Glycolysis / Q000187:drug effects*; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D061986:MCF-7 Cells; D001678:Organelle Biogenesis; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D016601:RNA-Binding Proteins; D011960:Receptors, Estrogen / Q000378:metabolism; D000097983:ERRalpha Estrogen-Related Receptor
chemical_list: D055372:AMP-Activated Protein Kinases; D000255:Adenosine Triphosphate; D000970:Antineoplastic Agents; D002352:Carrier Proteins; D017362:Cyclic AMP Response Element-Binding Protein; D003847:Deoxyglucose; D047428:Protein Kinase Inhibitors; D016601:RNA-Binding Proteins; D011960:Receptors, Estrogen; D000097983:ERRalpha Estrogen-Related Receptor; C455622:PPARGC1B protein, human