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Fernandez Garcia E, Paudel U, Noji MC, Bowman CE, Rustgi AK, Pitarresi JR, Wellen KE, Arany Z, Weissenrieder JS, Foskett JK. The mitochondrial Ca 2+ channel MCU is critical for tumor growth by supporting cell cycle progression and proliferation. Front Cell Dev Biol 2023; 11:1082213. [PMID: 37363724 PMCID: PMC10285664 DOI: 10.3389/fcell.2023.1082213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 05/09/2023] [Indexed: 06/28/2023] Open
Abstract
Introduction: The mitochondrial uniporter (MCU) Ca2+ ion channel represents the primary means for Ca2+ uptake by mitochondria. Mitochondrial matrix Ca2+ plays critical roles in mitochondrial bioenergetics by impinging upon respiration, energy production and flux of biochemical intermediates through the TCA cycle. Inhibition of MCU in oncogenic cell lines results in an energetic crisis and reduced cell proliferation unless media is supplemented with nucleosides, pyruvate or α-KG. Nevertheless, the roles of MCU-mediated Ca2+ influx in cancer cells remain unclear, in part because of a lack of genetic models. Methods: MCU was genetically deleted in transformed murine fibroblasts for study in vitro and in vivo. Tumor formation and growth were studied in murine xenograft models. Proliferation, cell invasion, spheroid formation and cell cycle progression were measured in vitro. The effects of MCU deletion on survival and cell-death were determined by probing for live/death markers. Mitochondrial bioenergetics were studied by measuring mitochondrial matrix Ca2+ concentration, membrane potential, global dehydrogenase activity, respiration, ROS production and inactivating-phosphorylation of pyruvate dehydrogenase. The effects of MCU rescue on metabolism were examined by tracing of glucose and glutamine utilization for fueling of mitochondrial respiration. Results: Transformation of primary fibroblasts in vitro was associated with increased MCU expression, enhanced MCU-mediated Ca2+ uptake, altered mitochondrial matrix Ca2+ concentration responses to agonist stimulation, suppression of inactivating-phosphorylation of pyruvate dehydrogenase and a modest increase of mitochondrial respiration. Genetic MCU deletion inhibited growth of HEK293T cells and transformed fibroblasts in mouse xenograft models, associated with reduced proliferation and delayed cell-cycle progression. MCU deletion inhibited cancer stem cell-like spheroid formation and cell invasion in vitro, both predictors of metastatic potential. Surprisingly, mitochondrial matrix [Ca2+], membrane potential, global dehydrogenase activity, respiration and ROS production were unaffected. In contrast, MCU deletion elevated glycolysis and glutaminolysis, strongly sensitized cell proliferation to glucose and glutamine limitation, and altered agonist-induced cytoplasmic Ca2+ signals. Conclusion: Our results reveal a dependence of tumorigenesis on MCU, mediated by a reliance on MCU for cell metabolism and Ca2+ dynamics necessary for cell-cycle progression and cell proliferation.
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Affiliation(s)
- Emily Fernandez Garcia
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Usha Paudel
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Michael C. Noji
- Department of Cancer Biology and Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Department of Medicine, Perelman School of Medicine, Cardiovascular Institute, University of Pennsylvania, Philadelphia, PA, United States
| | - Caitlyn E. Bowman
- Department of Medicine, Perelman School of Medicine, Cardiovascular Institute, University of Pennsylvania, Philadelphia, PA, United States
| | - Anil K. Rustgi
- Division of Digestive and Liver Diseases, Herbert Irving Comprehensive Cancer Center, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, United States
| | - Jason R. Pitarresi
- Division of Hematology/Oncology, Departments of Medicine and Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA, United States
| | - Kathryn E. Wellen
- Department of Cancer Biology and Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Zolt Arany
- Department of Medicine, Perelman School of Medicine, Cardiovascular Institute, University of Pennsylvania, Philadelphia, PA, United States
| | - Jillian S. Weissenrieder
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - J. Kevin Foskett
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
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García EF, Paudel U, Noji MC, Bowman CE, Pitarresi JR, Rustgi AK, Wellen KE, Arany Z, Weissenrieder JS, Foskett JK. The mitochondrial Ca 2+ channel MCU is critical for tumor growth by supporting cell cycle progression and proliferation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.26.538295. [PMID: 37163088 PMCID: PMC10168388 DOI: 10.1101/2023.04.26.538295] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The mitochondrial uniporter (MCU) Ca 2+ ion channel represents the primary means for Ca 2+ uptake into mitochondria. Here we employed in vitro and in vivo models with MCU genetically eliminated to understand how MCU contributes to tumor formation and progression. Transformation of primary fibroblasts in vitro was associated with increased MCU expression, enhanced mitochondrial Ca 2+ uptake, suppression of inactivating-phosphorylation of pyruvate dehydrogenase, a modest increase of basal mitochondrial respiration and a significant increase of acute Ca 2+ -dependent stimulation of mitochondrial respiration. Inhibition of mitochondrial Ca 2+ uptake by genetic deletion of MCU markedly inhibited growth of HEK293T cells and of transformed fibroblasts in mouse xenograft models. Reduced tumor growth was primarily a result of substantially reduced proliferation and fewer mitotic cells in vivo , and slower cell proliferation in vitro associated with delayed progression through S-phase of the cell cycle. MCU deletion inhibited cancer stem cell-like spheroid formation and cell invasion in vitro , both predictors of metastatic potential. Surprisingly, mitochondrial matrix Ca 2+ concentration, membrane potential, global dehydrogenase activity, respiration and ROS production were unchanged by genetic deletion of MCU in transformed cells. In contrast, MCU deletion elevated glycolysis and glutaminolysis, strongly sensitized cell proliferation to glucose and glutamine limitation, and altered agonist-induced cytoplasmic Ca 2+ signals. Our results reveal a dependence of tumorigenesis on MCU, mediated by a reliance on mitochondrial Ca 2+ uptake for cell metabolism and Ca 2+ dynamics necessary for cell-cycle progression and cell proliferation.
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Zhang C, Quinones A, Le A. Metabolic reservoir cycles in cancer. Semin Cancer Biol 2022; 86:180-188. [PMID: 35390455 PMCID: PMC9530070 DOI: 10.1016/j.semcancer.2022.03.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 03/15/2022] [Accepted: 03/24/2022] [Indexed: 01/27/2023]
Abstract
Cancer cells possess various biological processes to ensure survival and proliferation even under unfavorable conditions such as hypoxia, nutrient deprivation, and oxidative stress. One of the defining hallmarks of cancer cells is their ability to reprogram their metabolism to suit their needs. Building on over a decade of research in the field of cancer metabolism, numerous unique metabolic capabilities are still being discovered in the present day. One recent discovery in the field of cancer metabolism that was hitherto unexpected is the ability of cancer cells to store vital metabolites in forms that can be readily converted to glucose and glutamine for later use. We called these forms "metabolic reservoirs." While many studies have been conducted on storage molecules such as glycogen, triglyceride, and phosphocreatine (PCr), few have explored the concept of "metabolic reservoirs" for cancer as a whole. In this review, we will provide an overview of this concept, the previously known reservoirs including glycogen, triglyceride, and PCr, and the new discoveries made including the newly discovered reservoirs such as N-acetyl-aspartyl-glutamate (NAAG), lactate, and γ- aminobutyric acid (GABA). We will also discuss whether disrupting these reservoir cycles may be a new avenue for cancer treatment.
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Affiliation(s)
- Cissy Zhang
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | - Anne Le
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Chemical and Biomolecular Engineering, Johns Hopkins University Whiting School of Engineering, Baltimore, MD, USA.
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