Browse
Submit Data
Databases
API
Help

Dataset Information

29 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Cdc42-dependent modulation of rigidity sensing and cell spreading in tumor repopulating cells.

ABSTRACT: Recently, a robust mechanical method has been established to isolate a small subpopulation of highly tumorigenic tumor repopulating cells (TRCs) from parental melanoma cells. In order to characterize the molecular and mechanical properties of TRCs, we utilized the tension gauge tether (TGT) single-molecule platform and investigated force requirements during early cell spreading events. TRCs required the peak single molecular tension of around 40 pN through integrins for initial adhesion like the parental control cells, but unlike the control cells, they did not spread and formed very few mature focal adhesions (FAs). Single molecule resolution RNA quantification of three Rho GTPases showed that downregulation of Cdc42, but not Rac1, is responsible for the unusual biophysical features of TRCs and that a threshold level of Cdc42 transcripts per unit cell area is required to initiate cell spreading. Cdc42 overexpression rescued TRC spreading through FA formation and restored the sensitivity to tension cues such that TRCs, like parental control cells, increase cell spreading with increasing single-molecular tension cues. Our single molecule studies identified an unusual biophysical feature of suppressed spreading of TRCs that may enable us to distinguish TRC population from a pool of heterogeneous tumor cell population.

SUBMITTER: Chowdhury F

PROVIDER: S-EPMC6133653 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Efficient extravasation of tumor-repopulating cells depends on cell deformability.

Project description:Cancer metastasis is the most deadly stage in cancer progression. Despite significant efforts over the past decades, it remains elusive why only a very small fraction of cancer cells is able to generate micrometastasis and metastatic colonization. Recently we have shown that tumor-repopulating cells (TRCs), a highly tumorigenic subpopulation of mouse melanoma cells, can be selected by being cultured and grown in 3D soft fibrin gels. Here we show that when injected into the yolk of a 2 day-post-fertilization (dpf) embryo of Tg (fli1:EGFP or kdrl:mCherry) zebrafish, TRCs are much more efficient in surviving and growing at various secondary sites to generate micrometastasis and metastatic colonization than control melanoma cells that are grown on rigid plastic. The metastasis of TRCs is dependent on the presence of Sox2, a self-renewal gene, and silencing Sox2 leads to the inhibition of TRC metastasis. High-resolution of 3D confocal images of the TRCs at the secondary sites show that extravasation and formation of micrometastases by TRCs are more efficient than by the control cells. Remarkably, efficient extravasation of TRCs in vivo and transmigration in vitro are determined by TRC deformability, as a result of low Cdc42 and high Sox2. Our findings suggest that tumor cell deformability is a key factor in controlling extravasation dynamics during metastasis.

| S-EPMC4726408 | biostudies-literature

Rigidity of silicone substrates controls cell spreading and stem cell differentiation.

Project description:The dependences of spreading and differentiation of stem cells plated on hydrogel and silicone gel substrates on the rigidity and porosity of the substrates have recently been a subject of some controversy. In experiments on human mesenchymal stem cells plated on soft, medium rigidity, and hard silicone gels we show that harder gels are more osteogenic, softer gels are more adipogenic, and cell spreading areas increase with the silicone gel substrate rigidity. The results of our study indicate that substrate rigidity induces some universal cellular responses independently of the porosity or topography of the substrate.

| S-EPMC5030667 | biostudies-literature

Large and reversible myosin-dependent forces in rigidity sensing.

Project description:Cells sense the rigidity of their environment through localized pinching, which occurs when myosin molecular motors generate contractions within actin filaments anchoring the cell to its surroundings. We present high-resolution experiments performed on these elementary contractile units in cells. Our experimental results challenge the current understanding of molecular motor force generation. Surprisingly, bipolar myosin filaments generate much larger forces per motor than measured in single molecule experiments. Further, contraction to a fixed distance, followed by relaxation at the same rate, is observed over a wide range of matrix rigidities. Lastly, step-wise displacements of the matrix contacts are apparent during both contraction and relaxation. Building upon a generic two-state model of molecular motor collections, we interpret these unexpected observations as spontaneously emerging features of a collective motor behavior. Our approach explains why, in the cellular context, collections of resilient and slow motors contract in a stepwise fashion while collections of weak and fast motors do not. We thus rationalize the specificity of motor contractions implied in rigidity sensing compared to previous in vitro observations.

| S-EPMC8008990 | biostudies-literature

Reversing drug resistance of soft tumor-repopulating cells by tumor cell-derived chemotherapeutic microparticles.

Project description:Developing novel approaches to reverse the drug resistance of tumor-repopulating cells (TRCs) or stem cell-like cancer cells is an urgent clinical need to improve outcomes of cancer patients. Here we show an innovative approach that reverses drug resistance of TRCs using tumor cell-derived microparticles (T-MPs) containing anti-tumor drugs. TRCs, by virtue of being more deformable than differentiated cancer cells, preferentially take up T-MPs that release anti-tumor drugs after entering cells, which in turn lead to death of TRCs. The underlying mechanisms include interfering with drug efflux and promoting nuclear entry of the drugs. Our findings demonstrate the importance of tumor cell softness in uptake of T-MPs and effectiveness of a novel approach in reversing drug resistance of TRCs with promising clinical applications.

| S-EPMC4897183 | biostudies-literature

Downregulation of YAP-dependent Nupr1 promotes tumor-repopulating cell growth in soft matrices.

Project description:Despite decades of significant progress in understanding the molecular mechanisms of malignant tumorigenic cells, it remains elusive what these tumorigenic cells are and what controls the growth of these malignant cells. Recently, we have mechanically selected and grown highly malignant and tumorigenic tumor-repopulating cells (TRCs), a small sub-population of cancer cells, by culturing single cancer cells in soft fibrin matrices. However, it is unclear what regulates TRC growth besides Sox2. Here we show that nuclear protein 1 (Nupr1), a protein independent of Sox2, is downregulated in TRCs of melanoma, ovarian cancer and breast cancer cultured in soft fibrin matrices. Nupr1 expression depends on nuclear translocation of YAP that is enriched at the Nupr1 promoter sites; YAP is controlled by Cdc42-mediated F-actin and Lats1 interactions. Nupr1 regulates tumor-suppressor p53 and negatively regulates Nestin and Tert that are independent of Sox2 and promote TRC growth. Silencing Nupr1 increases TRC growth and Nupr1 overexpression inhibits TRC growth in culture and in immune-competent mice. Our results suggest that Nupr1 is a suppressor of growth of highly tumorigenic TRCs and may have a critical role in cancer progression.

| S-EPMC4848840 | biostudies-other

Stopping transformed cancer cell growth by rigidity sensing.

Project description:A common feature of cancer cells is the alteration of kinases and biochemical signalling pathways enabling transformed growth on soft matrices, whereas cytoskeletal protein alterations are thought to be a secondary issue. However, we report here that cancer cells from different tissues can be toggled between transformed and rigidity-dependent growth states by the absence or presence of mechanosensory modules, respectively. In various cancer lines from different tissues, cells had over tenfold fewer rigidity-sensing contractions compared with normal cells from the same tissues. Restoring normal levels of cytoskeletal proteins, including tropomyosins, restored rigidity sensing and rigidity-dependent growth. Further depletion of other rigidity sensor proteins, including myosin IIA, restored transformed growth and blocked sensing. In addition, restoration of rigidity sensing to cancer cells inhibited tumour formation and changed expression patterns. Thus, the depletion of rigidity-sensing modules through alterations in cytoskeletal protein levels enables cancer cell growth on soft surfaces, which is an enabling factor for cancer progression.

| S-EPMC7477912 | biostudies-literature

Soft fibrin matrix downregulates DAB2IP to promote Nanog-dependent growth of colon tumor-repopulating cells.

Project description:Colon cancer stem cells (CSCs) have been shown to be responsible for the recurrence and metastasis of colorectal cancer (CRC). As a crucial microenvironmental factor, extracellular matrix (ECM) stiffness is known to affect the stemness of CSCs. Recently, fibrin deposition in the stroma of CRC was demonstrated to be responsible for tumor development. In this study, we used salmon fibrin gel to provide a 3D ECM for colon cancer cells and investigated its effects on cell growth as well as the underlying mechanisms. Compared with stiff 420 Pascal (Pa) and 1 050 Pa gels, 90 Pa soft fibrin gel was most efficient at isolating and enriching tumor colonies. The size and number of colony formation negatively correlated with gel stiffness. Specifically, these tumor colonies exhibited efficient tumorigenicity, upregulated stem cell markers, and had anti-chemotherapeutic properties and were thus named tumor-repopulating cells (TRCs). More importantly, the self-renewal molecule Nanog was sharply induced in 3D-cultured colon TRCs; further, Nanog siRNA significantly inhibited colony formation, suggesting the indispensable role of Nanog in TRC growth. A subsequent mechanistic study illustrated that Nanog expression could be modulated through fibrin gel stiffness-induced DAB2IP/PI3K/FOXA1 signaling in colon TRCs.

| S-EPMC6377646 | biostudies-literature

Changes in E-cadherin rigidity sensing regulate cell adhesion.

Project description:Mechanical cues are sensed and transduced by cell adhesion complexes to regulate diverse cell behaviors. Extracellular matrix (ECM) rigidity sensing by integrin adhesions has been well studied, but rigidity sensing by cadherins during cell adhesion is largely unexplored. Using mechanically tunable polyacrylamide (PA) gels functionalized with the extracellular domain of E-cadherin (Ecad-Fc), we showed that E-cadherin-dependent epithelial cell adhesion was sensitive to changes in PA gel elastic modulus that produced striking differences in cell morphology, actin organization, and membrane dynamics. Traction force microscopy (TFM) revealed that cells produced the greatest tractions at the cell periphery, where distinct types of actin-based membrane protrusions formed. Cells responded to substrate rigidity by reorganizing the distribution and size of high-traction-stress regions at the cell periphery. Differences in adhesion and protrusion dynamics were mediated by balancing the activities of specific signaling molecules. Cell adhesion to a 30-kPa Ecad-Fc PA gel required Cdc42- and formin-dependent filopodia formation, whereas adhesion to a 60-kPa Ecad-Fc PA gel induced Arp2/3-dependent lamellipodial protrusions. A quantitative 3D cell-cell adhesion assay and live cell imaging of cell-cell contact formation revealed that inhibition of Cdc42, formin, and Arp2/3 activities blocked the initiation, but not the maintenance of established cell-cell adhesions. These results indicate that the same signaling molecules activated by E-cadherin rigidity sensing on PA gels contribute to actin organization and membrane dynamics during cell-cell adhesion. We hypothesize that a transition in the stiffness of E-cadherin homotypic interactions regulates actin and membrane dynamics during initial stages of cell-cell adhesion.

| S-EPMC5530647 | biostudies-literature

COL2A1 Is a Novel Biomarker of Melanoma Tumor Repopulating Cells.

Project description:Soft 3D-fibrin-gel selected tumor repopulating cells (TRCs) from the B16F1 melanoma cell line exhibit extraordinary self-renewal and tumor-regeneration capabilities. However, their biomarkers and gene regulatory features remain largely unknown. Here, we utilized the next-generation sequencing-based RNA sequencing (RNA-seq) technique to discover novel biomarkers and active gene regulatory features of TRCs. Systems biology analysis of RNA-seq data identified differentially expressed gene clusters, including the cell adhesion cluster, which subsequently identified highly specific and novel biomarkers, such as Col2a1, Ncam1, F11r, and Negr1. We validated the expression of these genes by real-time qPCR. The expression level of Col2a1 was found to be relatively low in TRCs but twenty-fold higher compared to the parental control cell line, thus making the biomarker very specific for TRCs. We validated the COL2A1 protein by immunofluorescence microscopy, showing a higher expression of COL2A1 in TRCs compared to parental control cells. KEGG pathway analysis showed the JAK/STAT, hypoxia, and Akt signaling pathways to be active in TRCs. Besides, the aerobic glycolysis pathway was found to be very active, indicating a typical Warburg Effect on highly tumorigenic cells. Together, our study revealed highly specific biomarkers and active cell signaling pathways of melanoma TRCs that can potentially target and neutralize TRCs.

| S-EPMC7555262 | biostudies-literature

Adaptive rheology and ordering of cell cytoskeleton govern matrix rigidity sensing.

Project description:Matrix rigidity sensing regulates a large variety of cellular processes and has important implications for tissue development and disease. However, how cells probe matrix rigidity, and hence respond to it, remains unclear. Here, we show that rigidity sensing and adaptation emerge naturally from actin cytoskeleton remodelling. Our in vitro experiments and theoretical modelling demonstrate a biphasic rheology of the actin cytoskeleton, which transitions from fluid on soft substrates to solid on stiffer ones. Furthermore, we find that increasing substrate stiffness correlates with the emergence of an orientational order in actin stress fibres, which exhibit an isotropic to nematic transition that we characterize quantitatively in the framework of active matter theory. These findings imply mechanisms mediated by a large-scale reinforcement of actin structures under stress, which could be the mechanical drivers of substrate stiffness-dependent cell shape changes and cell polarity.

| S-EPMC4599139 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data