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Cell shape and the microenvironment regulate nuclear translocation of NF- κ B in breast epithelial and tumor cells

View Article: PubMed Central - PubMed

ABSTRACT

Although a great deal is known about the signaling events that promote nuclear translocation of NF-κB, how cellular biophysics and the microenvironment might regulate the dynamics of this pathway is poorly understood. In this study, we used high-content image analysis and Bayesian network modeling to ask whether cell shape and context features influence NF-κB activation using the inherent variability present in unperturbed populations of breast tumor and non-tumor cell lines. Cell–cell contact, cell and nuclear area, and protrusiveness all contributed to variability in NF-κB localization in the absence and presence of TNFα. Higher levels of nuclear NF-κB were associated with mesenchymal-like versus epithelial-like morphologies, and RhoA-ROCK-myosin II signaling was critical for mediating shape-based differences in NF-κB localization and oscillations. Thus, mechanical factors such as cell shape and the microenvironment can influence NF-κB signaling and may in part explain how different phenotypic outcomes can arise from the same chemical cues.

No MeSH data available.


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The statistical dependency of YAP on cell shapeMCF10A cells stimulated with TNFα labeled for YAP and phospho-Jun. Scale bar = 20 μm.Frequency of YAP ratio dependencies by cell line for the most commonly connected features.Example Bayesian network model for YAP ratio (MDA-MB-231 cells).Dependencies of YAP ratio on the features that are most frequently connected to YAP ratio in unstimulated conditions. Red = dependency detected.
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fig03: The statistical dependency of YAP on cell shapeMCF10A cells stimulated with TNFα labeled for YAP and phospho-Jun. Scale bar = 20 μm.Frequency of YAP ratio dependencies by cell line for the most commonly connected features.Example Bayesian network model for YAP ratio (MDA-MB-231 cells).Dependencies of YAP ratio on the features that are most frequently connected to YAP ratio in unstimulated conditions. Red = dependency detected.

Mentions: To test the validity of this approach, we asked whether Bayesian network models could detect connections between cell shape features and localization of YAP, another transcription factor that is activated by nuclear translocation and is known to be regulated by cell density, spreading, and mechanical force (Fig3A, left) (Halder et al, 2012). Nuclear/cytoplasmic YAP ratios varied widely across ten cell lines (Fig3B) and were not significantly affected by 1-h TNFα treatment (Supplementary Fig S3A). YAP ratio was dependent on many of the same shape and context features as NF-κB ratio, specifically NF, ruffliness, and nuclear morphology features (7/10 lines each), but the networks were not identical. In MDA-MB-231 cells (genetic subtype Basal B, morphological group B), for example, YAP ratio was dependent on cell roundness, whereas NF-κB ratio was not (Figs2D and 3C). In MCF7 cells (Luminal, L1), NF-κB ratio was also highly connected to shape, but YAP ratio was only dependent on nuclear area (Figs2 and 3D). YAP ratio was most often dependent on NF and ruffliness. These data demonstrate that our experimental and analytical approach captures the known relationships between YAP nuclear localization and cell shape. Moreover, we find that the amount of nuclear YAP and NF-κB is dependent on overlapping, but not identical, aspects of cell morphology.


Cell shape and the microenvironment regulate nuclear translocation of NF- κ B in breast epithelial and tumor cells
The statistical dependency of YAP on cell shapeMCF10A cells stimulated with TNFα labeled for YAP and phospho-Jun. Scale bar = 20 μm.Frequency of YAP ratio dependencies by cell line for the most commonly connected features.Example Bayesian network model for YAP ratio (MDA-MB-231 cells).Dependencies of YAP ratio on the features that are most frequently connected to YAP ratio in unstimulated conditions. Red = dependency detected.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4380925&req=5

fig03: The statistical dependency of YAP on cell shapeMCF10A cells stimulated with TNFα labeled for YAP and phospho-Jun. Scale bar = 20 μm.Frequency of YAP ratio dependencies by cell line for the most commonly connected features.Example Bayesian network model for YAP ratio (MDA-MB-231 cells).Dependencies of YAP ratio on the features that are most frequently connected to YAP ratio in unstimulated conditions. Red = dependency detected.
Mentions: To test the validity of this approach, we asked whether Bayesian network models could detect connections between cell shape features and localization of YAP, another transcription factor that is activated by nuclear translocation and is known to be regulated by cell density, spreading, and mechanical force (Fig3A, left) (Halder et al, 2012). Nuclear/cytoplasmic YAP ratios varied widely across ten cell lines (Fig3B) and were not significantly affected by 1-h TNFα treatment (Supplementary Fig S3A). YAP ratio was dependent on many of the same shape and context features as NF-κB ratio, specifically NF, ruffliness, and nuclear morphology features (7/10 lines each), but the networks were not identical. In MDA-MB-231 cells (genetic subtype Basal B, morphological group B), for example, YAP ratio was dependent on cell roundness, whereas NF-κB ratio was not (Figs2D and 3C). In MCF7 cells (Luminal, L1), NF-κB ratio was also highly connected to shape, but YAP ratio was only dependent on nuclear area (Figs2 and 3D). YAP ratio was most often dependent on NF and ruffliness. These data demonstrate that our experimental and analytical approach captures the known relationships between YAP nuclear localization and cell shape. Moreover, we find that the amount of nuclear YAP and NF-κB is dependent on overlapping, but not identical, aspects of cell morphology.

View Article: PubMed Central - PubMed

ABSTRACT

Although a great deal is known about the signaling events that promote nuclear translocation of NF-κB, how cellular biophysics and the microenvironment might regulate the dynamics of this pathway is poorly understood. In this study, we used high-content image analysis and Bayesian network modeling to ask whether cell shape and context features influence NF-κB activation using the inherent variability present in unperturbed populations of breast tumor and non-tumor cell lines. Cell–cell contact, cell and nuclear area, and protrusiveness all contributed to variability in NF-κB localization in the absence and presence of TNFα. Higher levels of nuclear NF-κB were associated with mesenchymal-like versus epithelial-like morphologies, and RhoA-ROCK-myosin II signaling was critical for mediating shape-based differences in NF-κB localization and oscillations. Thus, mechanical factors such as cell shape and the microenvironment can influence NF-κB signaling and may in part explain how different phenotypic outcomes can arise from the same chemical cues.

No MeSH data available.


Related in: MedlinePlus