Modulation of Mitochondrial ERβ Expression Inhibits Triple-Negative Breast Cancer Tumor Progression by Activating Mitochondrial Function
| Autor: | Seung Hun Jeong, In-Sung Song, Tae-Hyun Kim, Yu Jeong Jeong, Jin Han, Sung-Wuk Jang, Ji Eun Kim |
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| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Mitochondrial ROS Physiology Estrogen receptor Triple Negative Breast Neoplasms Mitochondrion lcsh:Physiology Oxidative Phosphorylation lcsh:Biochemistry Mitochondrial Proteins Mice 03 medical and health sciences Adenosine Triphosphate 0302 clinical medicine Breast cancer Cell Line Tumor medicine Animals Estrogen Receptor beta Humans lcsh:QD415-436 HSP70 Heat-Shock Proteins RNA Small Interfering Triple-negative breast cancer Cell Proliferation Fluorescent Dyes Neoplasm Staging lcsh:QP1-981 Chemistry Cell growth Cell Cycle Cell cycle medicine.disease Survival Analysis Xenograft Model Antitumor Assays Mitochondria Gene Expression Regulation Neoplastic Protein Transport 030104 developmental biology Tumor progression 030220 oncology & carcinogenesis Cancer research Calcium Female Protein Binding Signal Transduction |
| Zdroj: | Cellular Physiology and Biochemistry, Vol 52, Iss 3, Pp 468-485 (2019) |
| ISSN: | 1421-9778 1015-8987 |
| DOI: | 10.33594/000000034 |
| Popis: | Background/aims Breast cancer is a clinically and molecularly heterogeneous disease. Patients with triple-negative breast cancer (TNBC) have poorer outcomes than those with other breast cancer subtypes due to lack of effective molecular targets for therapy. The present study aimed to the identification of estrogen receptor (ER)β as a novel mitochondrial target in TNBC cells, together with underlying mechanisms. Methods Expression of ERβ in clinical breast samples were examined by qRT-PCR, immunohistochemistry and immunoblotting. Subcellular distribution and binding of ERβ-Grp75 was determined by confocal microscopic analysis, co-immunoprecipitation experiments, and limited-detergent extraction of subcellular organelles. The effect of mitocondrial ERβ(mitoERβ) overexpression on cell proliferation and cell cycle distribution were assessed CCK-8 assays and FACS. Mitochondrial ROS, membrane potential, and Ca²⁺ level were measured using the specific fluorescent probes Mito-Sox, TMRE, and Rhod-2AM. The tumorigenic effect of mitoERβ overexpression was assessed using an anchorage-independent growth assay, sphere formation and a mouse orthotopic xenograft model. Results ERβ expression was lower in tumor tissue than in adjacent normal tissue of patients with breast cancer, and low levels of mitochondrial ERβ (mitoERβ) also were associated with increased tumor recurrence after surgery. Overexpression of mitoERβ inhibited the proliferation of TNBC cells and tumor masses in an animal model. Moreover, overexpression of mitoERβ increased ATP production in TNBC cells and normal breast MCF10A cells, with the latter completely reversed by mitoERβ knockdown in MCF10A cells. Grp75 was found to positively regulate ERβ translocation into mitochondria via a direct interaction. Coimmunoprecipitation and subcellular fractionation experiments revealed that ERβ-Grp75 complex is stable in mitochondria. Conclusion These results suggest that the up-regulation of mitoERβ in TNBC cells ensures proper mitochondrial transcription, activating the OXPHOS system to produce ATP. Studying the effects of mitoERβ on mitochondrial activity and specific mitochondrial gene expression in breast cancer might help predict tumor recurrence, inform clinical decision-making, and identify novel drug targets in the treatment of TNBC. |
| Databáze: | OpenAIRE |
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