1. PK-M2-mediated metabolic changes in breast cancer cells induced by ionizing radiation
- Author
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Zhang, Le, Bailleul, Justine, Yazal, Taha, Dong, Kevin, Sung, David, Dao, Amy, Gosa, Laura, Nathanson, David, Bhat, Kruttika, Duhachek-Muggy, Sara, Alli, Claudia, Dratver, Milana Bochkur, Pajonk, Frank, and Vlashi, Erina
- Subjects
Biomedical and Clinical Sciences ,Oncology and Carcinogenesis ,Breast Cancer ,Cancer ,Women's Health ,Radiation Oncology ,Stem Cell Research ,Stem Cell Research - Nonembryonic - Non-Human ,Carrier Proteins ,Cell Line ,Tumor ,Cell Nucleus ,Female ,Gene Expression Regulation ,Neoplastic ,Glucose ,Humans ,Lactic Acid ,Membrane Proteins ,Neoplastic Stem Cells ,Radiation ,Ionizing ,Thyroid Hormones ,Triple Negative Breast Neoplasms ,Up-Regulation ,Thyroid Hormone-Binding Proteins ,Pyruvate kinase ,Radiation therapy ,Breast cancer ,Metabolism ,Clinical Sciences ,Oncology & Carcinogenesis ,Clinical sciences ,Oncology and carcinogenesis - Abstract
PurposeRadiotherapy (RT) constitutes an important part of breast cancer treatment. However, triple negative breast cancers (TNBC) exhibit remarkable resistance to most therapies, including RT. Developing new ways to radiosensitize TNBC cells could result in improved patient outcomes. The M2 isoform of pyruvate kinase (PK-M2) is believed to be responsible for the re-wiring of cancer cell metabolism after oxidative stress. The aim of the study was to determine the effect of ionizing radiation (IR) on PK-M2-mediated metabolic changes in TNBC cells, and their survival. In addition, we determine the effect of PK-M2 activators on breast cancer stem cells, a radioresistant subpopulation of breast cancer stem cells.MethodsGlucose uptake, lactate production, and glutamine consumption were assessed. The cellular localization of PK-M2 was evaluated by western blot and confocal microscopy. The small molecule activator of PK-M2, TEPP46, was used to promote its pyruvate kinase function. Finally, effects on cancer stem cell were evaluated via sphere forming capacity.ResultsExposure of TNBC cells to IR increased their glucose uptake and lactate production. As expected, PK-M2 expression levels also increased, especially in the nucleus, although overall pyruvate kinase activity was decreased. PK-M2 nuclear localization was shown to be associated with breast cancer stem cells, and activation of PK-M2 by TEPP46 depleted this population.ConclusionsRadiotherapy can induce metabolic changes in TNBC cells, and these changes seem to be mediated, at least in part by PK-M2. Importantly, our results show that activators of PK-M2 can deplete breast cancer stem cells in vitro. This study supports the idea of combining PK-M2 activators with radiation to enhance the effect of radiotherapy in resistant cancers, such as TNBC.
- Published
- 2019