Combined Treatment of MCF-7 Cells with AICAR and Methotrexate, Arrests Cell Cycle and Reverses Warburg Metabolism through AMP-Activated Protein Kinase (AMPK) and FOXO1

Tamás Fodor; Magdolna Szántó; Omar Abdul-Rahman; Lilla Nagy; Ádám Dér; Borbála Kiss; Peter Bai

doi:10.1371/journal.pone.0150232

Combined Treatment of MCF-7 Cells with AICAR and Methotrexate, Arrests Cell Cycle and Reverses Warburg Metabolism through AMP-Activated Protein Kinase (AMPK) and FOXO1

PLoS One. 2016 Feb 26;11(2):e0150232. doi: 10.1371/journal.pone.0150232. eCollection 2016.

Authors

Tamás Fodor¹, Magdolna Szántó^{1

2}, Omar Abdul-Rahman^{1

2}, Lilla Nagy^{1

2}, Ádám Dér³, Borbála Kiss⁴, Peter Bai^{1

5

6}

Affiliations

¹ Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, H-4032, Hungary.
² MTA-DE Cell Biology and Signaling Research Group, Debrecen, H-4032, Hungary.
³ Department of Oncology, Section of Radiation Therapy, Faculty of Medicine, University of Debrecen, Debrecen, H-4032, Hungary.
⁴ Department of Dermatology, Faculty of Medicine, University of Debrecen, Debrecen, H-4032, Hungary.
⁵ MTA-DE Lendület Laboratory of Cellular Metabolism, Debrecen, H-4032, Hungary.
⁶ Research Center for Molecular Medicine, University of Debrecen, Debrecen, H-4032, Hungary.

Abstract

Cancer cells are characterized by metabolic alterations, namely, depressed mitochondrial oxidation, enhanced glycolysis and pentose phosphate shunt flux to support rapid cell growth, which is called the Warburg effect. In our study we assessed the metabolic consequences of a joint treatment of MCF-7 breast cancer cells with AICAR, an inducer of AMP-activated kinase (AMPK) jointly with methotrexate (MTX), a folate-analog antimetabolite that blunts de novo nucleotide synthesis. MCF7 cells, a model of breast cancer cells, were resistant to the individual application of AICAR or MTX, however combined treatment of AICAR and MTX reduced cell proliferation. Prolonged joint application of AICAR and MTX induced AMPK and consequently enhanced mitochondrial oxidation and reduced the rate of glycolysis. These metabolic changes suggest an anti-Warburg rearrangement of metabolism that led to the block of the G1/S and the G2/M transition slowing down cell cycle. The slowdown of cell proliferation was abolished when mitotropic transcription factors, PGC-1α, PGC-1β or FOXO1 were silenced. In human breast cancers higher expression of AMPKα and FOXO1 extended survival. AICAR and MTX exerts similar additive antiproliferative effect on other breast cancer cell lines, such as SKBR and 4T1 cells, too. Our data not only underline the importance of Warburg metabolism in breast cancer cells but nominate the AICAR+MTX combination as a potential cytostatic regime blunting Warburg metabolism. Furthermore, we suggest the targeting of AMPK and FOXO1 to combat breast cancer.

Publication types

Comparative Study
Research Support, Non-U.S. Gov't

MeSH terms

AMP-Activated Protein Kinases / metabolism*
Aminoimidazole Carboxamide / administration & dosage
Aminoimidazole Carboxamide / analogs & derivatives*
Aminoimidazole Carboxamide / pharmacology
Antimetabolites, Antineoplastic / pharmacology
Antineoplastic Combined Chemotherapy Protocols / pharmacology*
Bone Neoplasms / pathology
Breast Neoplasms / genetics
Breast Neoplasms / metabolism
Breast Neoplasms / mortality
Breast Neoplasms / pathology*
Cell Cycle / drug effects
Cell Division / drug effects
Cell Line, Tumor
Cytostatic Agents / administration & dosage
Cytostatic Agents / pharmacology*
Drug Screening Assays, Antitumor
Drug Synergism
Energy Metabolism / drug effects*
Enzyme Induction / drug effects
Female
Forkhead Box Protein O1
Forkhead Transcription Factors / metabolism*
Gene Expression Regulation, Neoplastic
Glycolysis / drug effects
Humans
Lactates / metabolism
MCF-7 Cells
Membrane Potential, Mitochondrial / drug effects
Methotrexate / administration & dosage
Methotrexate / pharmacology*
Molecular Targeted Therapy
Neoplasm Proteins / metabolism*
Osteosarcoma / pathology
RNA Interference
Ribonucleotides / administration & dosage
Ribonucleotides / pharmacology*
Transcription Factors / antagonists & inhibitors

Substances

Antimetabolites, Antineoplastic
Cytostatic Agents
FOXO1 protein, human
Forkhead Box Protein O1
Forkhead Transcription Factors
Lactates
Neoplasm Proteins
Ribonucleotides
Transcription Factors
Aminoimidazole Carboxamide
AMP-Activated Protein Kinases
AICA ribonucleotide
Methotrexate

Grants and funding

The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The author(s) received no specific funding for this work. The authors acknowledge the technical assistance of Erzsébet Herbály and László Gelenczei-Finta. This work was supported by a Bolyai fellowship to MS. Furthermore, by grants from The Hungarian National, Research, Development and Innovation Office (NKFIH (K108308, K105872, C120732, C129074)), TÁMOP-4.2.2. A-11/1/KONV-2012-0025, the Momentum fellowship of the Hungarian Academy of Sciences and the University of Debrecen.