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Mitochondrial biogenesis is required for the anchorage-independent survival and propagation of stem-like cancer cells.

De Luca A, Fiorillo M, Peiris-Pagès M, Ozsvari B, Smith DL, Sanchez-Alvarez R, Martinez-Outschoorn UE, Cappello AR, Pezzi V, Lisanti MP, Sotgia F - Oncotarget (2015)

Bottom Line: We also show that XCT790 markedly reduces oxidative mitochondrial metabolism (OXPHOS) and that XCT790-mediated inhibition of CSC propagation can be prevented or reversed by Acetyl-L-Carnitine (ALCAR), a mitochondrial fuel.In this context, our unbiased proteomics analysis reveals that FOXM1 drives the expression of >90 protein targets associated with mitochondrial biogenesis, glycolysis, the EMT and protein synthesis in MCF7 cells, processes which are characteristic of an anabolic CSC phenotype.As such, doxycycline could be re-purposed clinically as a 'safe' mitochondrial inhibitor, to target FOXM1 and mitochondrial biogenesis in CSCs, to prevent tumor recurrence and distant metastasis, thereby avoiding patient relapse.

View Article: PubMed Central - PubMed

Affiliation: The Breakthrough Breast Cancer Research Unit, Institute of Cancer Sciences, University of Manchester, UK.

ABSTRACT
Here, we show that new mitochondrial biogenesis is required for the anchorage independent survival and propagation of cancer stem-like cells (CSCs). More specifically, we used the drug XCT790 as an investigational tool, as it functions as a specific inhibitor of the ERRα-PGC1 signaling pathway, which governs mitochondrial biogenesis. Interestingly, our results directly demonstrate that XCT790 efficiently blocks both the survival and propagation of tumor initiating stem-like cells (TICs), using the MCF7 cell line as a model system. Mechanistically, we show that XCT790 suppresses the activity of several independent signaling pathways that are normally required for the survival of CSCs, such as Sonic hedgehog, TGFβ-SMAD, STAT3, and Wnt signaling. We also show that XCT790 markedly reduces oxidative mitochondrial metabolism (OXPHOS) and that XCT790-mediated inhibition of CSC propagation can be prevented or reversed by Acetyl-L-Carnitine (ALCAR), a mitochondrial fuel. Consistent with our findings, over-expression of ERRα significantly enhances the efficiency of mammosphere formation, which can be blocked by treatment with mitochondrial inhibitors. Similarly, mammosphere formation augmented by FOXM1, a downstream target of Wnt/β-catenin signaling, can also be blocked by treatment with three different classes of mitochondrial inhibitors (XCT790, oligomycin A, or doxycycline). In this context, our unbiased proteomics analysis reveals that FOXM1 drives the expression of >90 protein targets associated with mitochondrial biogenesis, glycolysis, the EMT and protein synthesis in MCF7 cells, processes which are characteristic of an anabolic CSC phenotype. Finally, doxycycline is an FDA-approved antibiotic, which is very well-tolerated in patients. As such, doxycycline could be re-purposed clinically as a 'safe' mitochondrial inhibitor, to target FOXM1 and mitochondrial biogenesis in CSCs, to prevent tumor recurrence and distant metastasis, thereby avoiding patient relapse.

No MeSH data available.


Related in: MedlinePlus

ERRα expression is required for 3D-spheroid formation in MCF7 cellsERRα was over-expressed in MCF7 cells using a lentiviral approach. Empty Vector (EV) cells were generated in parallel. A. MCF7 cells overexpressing ERRα show a 50% increase in mammosphere forming capacity, relative to EV controls. B. MCF7 cells over-expressing ERRα show an increase of mitochondrial membrane potential, as assessed by MitoTracker Orange staining, as well as an increase in mitochondrial mass, as assessed by MitoTracker Green and MitoTracker Deep Red staining, as expected. C. Oligomycin A, an inhibitor of mitochondrial ATP synthase, inhibits mammosphere formation in MCF7 cells overexpressing ERRα, indicating that mitochondrial function is required for ERRα-driven mammosphere formation. D. XCT790, an ERRα inverse agonist, inhibits mammosphere formation in MCF7 cells over-expressing ERRα. Thus, ERRα activity is required for the efficient clonal expansion of TICs. EV: Empty Vector. *p < 0.05, **p < 0.01, ***p < 0.001 evaluated by Student's t test.
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Figure 7: ERRα expression is required for 3D-spheroid formation in MCF7 cellsERRα was over-expressed in MCF7 cells using a lentiviral approach. Empty Vector (EV) cells were generated in parallel. A. MCF7 cells overexpressing ERRα show a 50% increase in mammosphere forming capacity, relative to EV controls. B. MCF7 cells over-expressing ERRα show an increase of mitochondrial membrane potential, as assessed by MitoTracker Orange staining, as well as an increase in mitochondrial mass, as assessed by MitoTracker Green and MitoTracker Deep Red staining, as expected. C. Oligomycin A, an inhibitor of mitochondrial ATP synthase, inhibits mammosphere formation in MCF7 cells overexpressing ERRα, indicating that mitochondrial function is required for ERRα-driven mammosphere formation. D. XCT790, an ERRα inverse agonist, inhibits mammosphere formation in MCF7 cells over-expressing ERRα. Thus, ERRα activity is required for the efficient clonal expansion of TICs. EV: Empty Vector. *p < 0.05, **p < 0.01, ***p < 0.001 evaluated by Student's t test.

Mentions: XCT790 is an inverse agonist of ERRα. As XCT790 inhibits mammosphere formation, we then asked if ERRα expression is sufficient to promote 3D-spheroid formation in MCF7 cells. To this end, ERRα was over-expressed in MCF7 cells using a lentiviral approach. Empty Vector (EV) cells were generated in parallel. Figure 7A shows that MCF7 cells over-expressing ERRα show a 50% increase in mammosphere forming capacity. Notably, MCF7 cells over-expressing ERRα show increased mitochondrial membrane potential, as assessed by MitoTracker Orange, as well as increased mitochondrial mass, as assessed by MitoTracker Green and MitoTracker Deep Red, as expected (Figure 7B).


Mitochondrial biogenesis is required for the anchorage-independent survival and propagation of stem-like cancer cells.

De Luca A, Fiorillo M, Peiris-Pagès M, Ozsvari B, Smith DL, Sanchez-Alvarez R, Martinez-Outschoorn UE, Cappello AR, Pezzi V, Lisanti MP, Sotgia F - Oncotarget (2015)

ERRα expression is required for 3D-spheroid formation in MCF7 cellsERRα was over-expressed in MCF7 cells using a lentiviral approach. Empty Vector (EV) cells were generated in parallel. A. MCF7 cells overexpressing ERRα show a 50% increase in mammosphere forming capacity, relative to EV controls. B. MCF7 cells over-expressing ERRα show an increase of mitochondrial membrane potential, as assessed by MitoTracker Orange staining, as well as an increase in mitochondrial mass, as assessed by MitoTracker Green and MitoTracker Deep Red staining, as expected. C. Oligomycin A, an inhibitor of mitochondrial ATP synthase, inhibits mammosphere formation in MCF7 cells overexpressing ERRα, indicating that mitochondrial function is required for ERRα-driven mammosphere formation. D. XCT790, an ERRα inverse agonist, inhibits mammosphere formation in MCF7 cells over-expressing ERRα. Thus, ERRα activity is required for the efficient clonal expansion of TICs. EV: Empty Vector. *p < 0.05, **p < 0.01, ***p < 0.001 evaluated by Student's t test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4558115&req=5

Figure 7: ERRα expression is required for 3D-spheroid formation in MCF7 cellsERRα was over-expressed in MCF7 cells using a lentiviral approach. Empty Vector (EV) cells were generated in parallel. A. MCF7 cells overexpressing ERRα show a 50% increase in mammosphere forming capacity, relative to EV controls. B. MCF7 cells over-expressing ERRα show an increase of mitochondrial membrane potential, as assessed by MitoTracker Orange staining, as well as an increase in mitochondrial mass, as assessed by MitoTracker Green and MitoTracker Deep Red staining, as expected. C. Oligomycin A, an inhibitor of mitochondrial ATP synthase, inhibits mammosphere formation in MCF7 cells overexpressing ERRα, indicating that mitochondrial function is required for ERRα-driven mammosphere formation. D. XCT790, an ERRα inverse agonist, inhibits mammosphere formation in MCF7 cells over-expressing ERRα. Thus, ERRα activity is required for the efficient clonal expansion of TICs. EV: Empty Vector. *p < 0.05, **p < 0.01, ***p < 0.001 evaluated by Student's t test.
Mentions: XCT790 is an inverse agonist of ERRα. As XCT790 inhibits mammosphere formation, we then asked if ERRα expression is sufficient to promote 3D-spheroid formation in MCF7 cells. To this end, ERRα was over-expressed in MCF7 cells using a lentiviral approach. Empty Vector (EV) cells were generated in parallel. Figure 7A shows that MCF7 cells over-expressing ERRα show a 50% increase in mammosphere forming capacity. Notably, MCF7 cells over-expressing ERRα show increased mitochondrial membrane potential, as assessed by MitoTracker Orange, as well as increased mitochondrial mass, as assessed by MitoTracker Green and MitoTracker Deep Red, as expected (Figure 7B).

Bottom Line: We also show that XCT790 markedly reduces oxidative mitochondrial metabolism (OXPHOS) and that XCT790-mediated inhibition of CSC propagation can be prevented or reversed by Acetyl-L-Carnitine (ALCAR), a mitochondrial fuel.In this context, our unbiased proteomics analysis reveals that FOXM1 drives the expression of >90 protein targets associated with mitochondrial biogenesis, glycolysis, the EMT and protein synthesis in MCF7 cells, processes which are characteristic of an anabolic CSC phenotype.As such, doxycycline could be re-purposed clinically as a 'safe' mitochondrial inhibitor, to target FOXM1 and mitochondrial biogenesis in CSCs, to prevent tumor recurrence and distant metastasis, thereby avoiding patient relapse.

View Article: PubMed Central - PubMed

Affiliation: The Breakthrough Breast Cancer Research Unit, Institute of Cancer Sciences, University of Manchester, UK.

ABSTRACT
Here, we show that new mitochondrial biogenesis is required for the anchorage independent survival and propagation of cancer stem-like cells (CSCs). More specifically, we used the drug XCT790 as an investigational tool, as it functions as a specific inhibitor of the ERRα-PGC1 signaling pathway, which governs mitochondrial biogenesis. Interestingly, our results directly demonstrate that XCT790 efficiently blocks both the survival and propagation of tumor initiating stem-like cells (TICs), using the MCF7 cell line as a model system. Mechanistically, we show that XCT790 suppresses the activity of several independent signaling pathways that are normally required for the survival of CSCs, such as Sonic hedgehog, TGFβ-SMAD, STAT3, and Wnt signaling. We also show that XCT790 markedly reduces oxidative mitochondrial metabolism (OXPHOS) and that XCT790-mediated inhibition of CSC propagation can be prevented or reversed by Acetyl-L-Carnitine (ALCAR), a mitochondrial fuel. Consistent with our findings, over-expression of ERRα significantly enhances the efficiency of mammosphere formation, which can be blocked by treatment with mitochondrial inhibitors. Similarly, mammosphere formation augmented by FOXM1, a downstream target of Wnt/β-catenin signaling, can also be blocked by treatment with three different classes of mitochondrial inhibitors (XCT790, oligomycin A, or doxycycline). In this context, our unbiased proteomics analysis reveals that FOXM1 drives the expression of >90 protein targets associated with mitochondrial biogenesis, glycolysis, the EMT and protein synthesis in MCF7 cells, processes which are characteristic of an anabolic CSC phenotype. Finally, doxycycline is an FDA-approved antibiotic, which is very well-tolerated in patients. As such, doxycycline could be re-purposed clinically as a 'safe' mitochondrial inhibitor, to target FOXM1 and mitochondrial biogenesis in CSCs, to prevent tumor recurrence and distant metastasis, thereby avoiding patient relapse.

No MeSH data available.


Related in: MedlinePlus