15 research outputs found
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Author Correction: Automated segmentation and tracking of mitochondria in live-cell time-lapse images
No full textIn the version of this article originally published, there was an omission in the Acknowledgements section. The text “This work was also supported in part by American Cancer Society Institutional Research Grant 134045-IRG-19-145-16-IRG” has now been added to the HTML and PDF versions of the article
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Collagen density modulates triple-negative breast cancer cell metabolism through adhesion-mediated contractility
No full textExtracellular matrix (ECM) mechanical properties upregulate cancer invasion, cell contractility, and focal adhesion formation. Alteration in energy metabolism is a known characteristic of cancer cells (i.e., Warburg effect) and modulates cell invasion. There is little evidence to show if collagen density can alter cancer cell metabolism. We investigated changes in energy metabolism due to collagen density in five breast cell lines by measuring the fluorescence lifetime of NADH. We found that only triple-negative breast cancer cells, MDA-MB231 and MDA-MB468 cells, had an increased population of bound NADH, indicating an oxidative phosphorylation (OXPHOS) signature, as collagen density decreased. When inhibiting ROCK and cell contractility, MDA-MB231 cells on glass shifted from glycolysis (GLY) to OXPHOS, confirming the intricate relationship between mechanosensing and metabolism. MCF10A cells showed less significant changes in metabolism, shifting towards GLY as collagen density decreased. The MCF-7 and T-47D, less invasive breast cancer cells, compared to the MDA-MB231 and MDA-MB468 cells, showed no changes regardless of substrate. In addition, OXPHOS or GLY inhibitors in MDA-MB231 cells showed dramatic shifts from OXPHOS to GLY or vice versa. These results provide an important link between cellular metabolism, contractility, and collagen density in human breast cancer
Collagen density modulates triple-negative breast cancer cell metabolism through adhesion-mediated contractility
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CDCP1/mitochondrial Src axis increases electron transport chain function to promote metastasis in triple-negative breast cancer
No full textBackgroundTriple-negative type of breast cancer (TNBC) has limited therapeutic options and frequently metastasizes, leading to low survival rates. Oxidative phosphorylation (OXPHOS) is a driver of TNBC metastasis, but the signaling underlying this metabolic change is poorly understood.MethodsWe performed metabolic assays and assessed migratory and metastatic potential in cells with manipulated CDCP1/mitochondrial Src signaling.ResultsWe show that the pro-metastatic cell surface protein CUB-domain containing protein 1 (CDCP1) activates Src kinase localized in mitochondria, which potently induces OXPHOS and TNBC migration. Genetic targeting of either CDCP1 or mitochondrial Src, as well as pharmacological inhibition of Src reduce OXPHOS in vitro. We further show that mitochondrial Src increases OXPHOS by stimulating Complex I activity in the electron transport chain. Importantly, rescuing Complex I activity in cells devoid of CDCP1/mitochondrial Src signaling restores both OXPHOS and migration. We also provide evidence that NAD+ pool generated by Complex I is contributing to the observed migratory phenotype. Lastly, we determined that inhibiting mitochondrial Src reduces metastasis in TNBC cells.ConclusionsBoth CDCP1 and mitochondrial Src represent potential therapeutic targets to inhibit OXPHOS-mediated TNBC metastasis
Microenvironmental stiffness induces metabolic reprogramming in glioblastoma
No full textThe mechanical properties of solid tumors influence tumor cell phenotype and the ability to invade surrounding tissues. Using bioengineered scaffolds to provide a matrix microenvironment for patient-derived glioblastoma (GBM) spheroids, this study demonstrates that a soft, brain-like matrix induces GBM cells to shift to a glycolysis-weighted metabolic state, which supports invasive behavior. We first show that orthotopic murine GBM tumors are stiffer than peritumoral brain tissues, but tumor stiffness is heterogeneous where tumor edges are softer than the tumor core. We then developed 3D scaffolds with μ-compressive moduli resembling either stiffer tumor core or softer peritumoral brain tissue. We demonstrate that the softer matrix microenvironment induces a shift in GBM cell metabolism toward glycolysis, which manifests in lower proliferation rate and increased migration activities. Finally, we show that these mechanical cues are transduced from the matrix via CD44 and integrin receptors to induce metabolic and phenotypic changes in cancer cells
Disruption of the circadian clock drives Apc loss of heterozygosity to accelerate colorectal cancer
No full textThe actin binding protein profilin 1 localizes inside mitochondria and is critical for their function
No full textAbstract The monomer-binding protein profilin 1 (PFN1) plays a crucial role in actin polymerization. However, mutations in PFN1 are also linked to hereditary amyotrophic lateral sclerosis, resulting in a broad range of cellular pathologies which cannot be explained by its primary function as a cytosolic actin assembly factor. This implies that there are important, undiscovered roles for PFN1 in cellular physiology. Here we screened knockout cells for novel phenotypes associated with PFN1 loss of function and discovered that mitophagy was significantly upregulated. Indeed, despite successful autophagosome formation, fusion with the lysosome, and activation of additional mitochondrial quality control pathways, PFN1 knockout cells accumulate depolarized, dysmorphic mitochondria with altered metabolic properties. Surprisingly, we also discovered that PFN1 is present inside mitochondria and provide evidence that mitochondrial defects associated with PFN1 loss are not caused by reduced actin polymerization in the cytosol. These findings suggest a previously unrecognized role for PFN1 in maintaining mitochondrial integrity and highlight new pathogenic mechanisms that can result from PFN1 dysregulation
Patient-derived xenograft culture-transplant system for investigation of human breast cancer metastasis
No full textPatient-derived xenograft culture-transplant system for investigation of human breast cancer metastasis
No full textMetastasis is a fatal disease where research progress has been hindered by a lack of authentic experimental models. Here, we develop a 3D tumor sphere culture-transplant system that facilitates the growth and engineering of patient-derived xenograft (PDX) tumor cells for functional metastasis assays in vivo. Orthotopic transplantation and RNA sequencing (RNA-seq) analyses show that PDX tumor spheres maintain tumorigenic potential, and the molecular marker and global transcriptome signatures of native tumor cells. Tumor spheres display robust capacity for lentiviral engineering and dissemination in spontaneous and experimental metastasis assays in vivo. Inhibition of pathways previously reported to attenuate metastasis also inhibit metastasis after sphere culture, validating our approach for authentic investigations of metastasis. Finally, we demonstrate a new role for the metabolic enzyme NME1 in promoting breast cancer metastasis, providing proof-of-principle that our culture-transplant system can be used for authentic propagation and engineering of patient tumor cells for functional studies of metastasis
