scholarly journals Hypoxia, Partial EMT and Collective Migration: Emerging Culprits in Metastasis

Author(s):  
Kritika Saxena ◽  
Mohit Kumar Jolly ◽  
Kuppusamy Balamurugan

Epithelial-mesenchymal transition (EMT) is a cellular biological process involved in migration of primary cancer cells to secondary sites facilitating metastasis. Besides, EMT also confers properties such as stemness, drug resistance and immune evasion which can aid a successful colonization at the distant site. EMT is not a binary process; recent evidence suggests that cells in partial EMT or hybrid E/M phenotype(s) can have enhanced stemness and drug resistance as compared to those undergoing a complete EMT. Moreover, partial EMT enables collective migration of cells as clusters of circulating tumor cells or emboli, further endorsing that cells in hybrid E/M phenotypes may be the ‘fittest’ for metastasis. Here, we review mechanisms and implications of hybrid E/M phenotypes, including their reported association with hypoxia. Hypoxia-driven activation of HIF-1α can drive EMT. In addition, cyclic hypoxia, as compared to acute or chronic hypoxia, shows the highest levels of active HIF-1α and can augment cancer aggressiveness to a greater extent, including enriching for a partial EMT phenotype. We also discuss how metastasis is influenced by hypoxia, partial EMT and collective cell migration, and call for a better understanding of interconnections among these mechanisms. We discuss the known regulators of hypoxia, hybrid EMT and collective cell migration and highlight the gaps which needs to be filled for connecting these three axes which will increase our understanding of dynamics of metastasis and help control it more effectively.

2021 ◽  
Vol 8 (5) ◽  
pp. 65
Author(s):  
Song-Yi Park ◽  
Hwanseok Jang ◽  
Seon-Young Kim ◽  
Dasarang Kim ◽  
Yongdoo Park ◽  
...  

Collective cell migration of epithelial tumor cells is one of the important factors for elucidating cancer metastasis and developing novel drugs for cancer treatment. Especially, new roles of E-cadherin in cancer migration and metastasis, beyond the epithelial–mesenchymal transition, have recently been unveiled. Here, we quantitatively examined cell motility using micropatterned free edge migration model with E-cadherin re-expressing EC96 cells derived from adenocarcinoma gastric (AGS) cell line. EC96 cells showed increased migration features such as the expansion of cell islands and straightforward movement compared to AGS cells. The function of tight junction proteins known to E-cadherin expression were evaluated for cell migration by knockdown using sh-RNA. Cell migration and straight movement of EC96 cells were reduced by knockdown of ZO-1 and claudin-7, to a lesser degree. Analysis of the migratory activity of boundary cells and inner cells shows that EC96 cell migration was primarily conducted by boundary cells, similar to leader cells in collective migration. Immunofluorescence analysis showed that tight junctions (TJs) of EC96 cells might play important roles in intracellular communication among boundary cells. ZO-1 is localized to the base of protruding lamellipodia and cell contact sites at the rear of cells, indicating that ZO-1 might be important for the interaction between traction and tensile forces. Overall, dynamic regulation of E-cadherin expression and localization by interaction with ZO-1 protein is one of the targets for elucidating the mechanism of collective migration of cancer metastasis.


2015 ◽  
Vol 26 (25) ◽  
pp. 4577-4588 ◽  
Author(s):  
M. Hunter Lanier ◽  
Taekyung Kim ◽  
John A. Cooper

Cancer cell migration requires the regulation of actin networks at protrusions associated with invadopodia and other leading edges. Carcinomas become invasive after undergoing an epithelial–mesenchymal transition characterized by the appearance of vimentin filaments. While vimentin expression correlates with cell migration, the molecular connections between vimentin- and actin-based membrane protrusions are not understood. We report here that CARMIL2 (capping protein, Arp2/3, myosin-I linker 2) provides such a molecular link. CARMIL2 localizes to vimentin, regulates actin capping protein (CP), and binds to membranes. CARMIL2 is necessary for invadopodia formation, as well as cell polarity, lamellipodial assembly, membrane ruffling, macropinocytosis, and collective cell migration. Using point mutants and chimeras with defined biochemical and cellular properties, we discovered that localization to vimentin and CP binding are both essential for the function of CARMIL2 in cells. On the basis of these results, we propose a model in which dynamic vimentin filaments target CARMIL2 to critical membrane-associated locations, where CARMIL2 regulates CP, and thus actin assembly, to create cell protrusions.


2021 ◽  
Author(s):  
Yinci Zhang ◽  
Niandie Cao ◽  
Jiafeng Gao ◽  
Jiaojiao Liang ◽  
Yong Liang ◽  
...  

Abstract Background: The main obstacle to the cure of hepatocellular carcinoma (HCC) is multidrug resistance. Acid sensing ion channel 1a (ASIC1a) acts as a critical roles in all stages of cancer progression, especially invasion and metastasis as well as in resistance to therapy. Epithelial to mesenchymal transition (EMT) is a phenomenon in which epithelial cells transform into mesenchymal cells after being stimulated by extracellular factors and is closely related to tumor infiltration and resistance. Methods: Western blotting assay, Immunofluorescence (IF) staining, Immunohistochemistry (IHC) staining, MTT and colony formation assay and scratch healing assay were used to detect the level of ASIC1a and the cell proliferation, migration and invasion capabilities in this research.Results: In this research, we found that the protein of ASIC1a is overexpressed in HCC cancer tissues. In addition, we identified that the levels of ASIC1a are highly expressed in resistant HCC cells. Compared with the parental cells, EMT occurred more frequently in drug-resistant cells. Functional studies demonstrated that inactivation of ASIC1a restrained cell migration and invasion and enhanced the chemosensitivity of cells through EMT. In HCC cells, the overexpression of ASIC1a stimulates the up-regulation of EMT characterization molecular level and proliferation, migration and invasion capabilities and further induces drug resistance, while knocking down ASIC1a with short hairpin RNA (shRNA) has the opposite effect. Further investigations found that ASIC1a increased cell migration and invasion through EMT by regulating α and β-catenin, vimentin and fibronectin expression via AKT/GSK-3β/Snail pathway. Conclusions: Our study demonstrated that ASIC1a acts an important assignment in drug resistance of HCC through EMT via AKT/GSK-3β/Snail pathway, thereby lending a latent therapeutic objective and new ideas regarding to HCC.


2014 ◽  
Vol 206 (1) ◽  
pp. 113-127 ◽  
Author(s):  
Sei Kuriyama ◽  
Eric Theveneau ◽  
Alexandre Benedetto ◽  
Maddy Parsons ◽  
Masamitsu Tanaka ◽  
...  

Collective cell migration (CCM) and epithelial–mesenchymal transition (EMT) are common to cancer and morphogenesis, and are often considered to be mutually exclusive in spite of the fact that many cancer and embryonic cells that have gone through EMT still cooperate to migrate collectively. Here we use neural crest (NC) cells to address the question of how cells that have down-regulated cell–cell adhesions can migrate collectively. NC cell dissociation relies on a qualitative and quantitative change of the cadherin repertoire. We found that the level of cell–cell adhesion is precisely regulated by internalization of N-cadherin downstream of lysophosphatidic acid (LPA) receptor 2. Rather than promoting the generation of single, fully mesenchymal cells, this reduction of membrane N-cadherin only triggers a partial mesenchymal phenotype. This intermediate phenotype is characterized by an increase in tissue fluidity akin to a solid-like–to–fluid-like transition. This change of plasticity allows cells to migrate under physical constraints without abolishing cell cooperation required for collectiveness.


Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3708
Author(s):  
Inés Sáenz-de-Santa-María ◽  
Lucía Celada ◽  
Andrés San José Martínez ◽  
Tamara Cubiella ◽  
María-Dolores Chiara

Metastasis remains a clinically unsolved issue in cancer that is initiated by the acquisition of collective migratory properties of cancer cells. Phenotypic and functional heterogeneity that arise among cancer cells within the same tumor increase cellular plasticity and promote metastasis, however, their impact on collective cell migration is incompletely understood. Here, we show that in vitro collective cancer cell migration depends on FAK and MMP-2 and on the presence of cancer-associated fibroblasts (CAFs). The absence of functional FAK rendered cancer cells incapable of invading the surrounding stroma. However, CAFs and cancer cells over-expressing MMP-2 released FAK-deficient cells from this constraint by taking the leader positions in the invasive tracks, pushing FAK-deficient squamous cell carcinoma (SCC) cells towards the stroma and leading to the transformation of non-invasive cells into invasive cells. Our cell-based studies and the RNAseq data from the TCGA cohort of patients with head and neck squamous cell carcinomas reveal that, although both FAK and MMP-2 over-expression are associated with epithelial–mesenchymal transition, it is only MMP-2, not FAK, that functions as an independent prognostic factor. Given the significant role of MMP-2 in cancer dissemination, targeting of this molecule, better than FAK, presents a more promising opportunity to block metastasis.


2017 ◽  
Vol 14 (136) ◽  
pp. 20170512 ◽  
Author(s):  
Federico Bocci ◽  
Mohit K. Jolly ◽  
Satyendra C. Tripathi ◽  
Mitzi Aguilar ◽  
Samir M. Hanash ◽  
...  

Epithelial–mesenchymal transition (EMT) plays key roles during embryonic development, wound healing and cancer metastasis. Cells in a partial EMT or hybrid epithelial/mesenchymal (E/M) phenotype exhibit collective cell migration, forming clusters of circulating tumour cells—the primary drivers of metastasis. Activation of cell–cell signalling pathways such as Notch fosters a partial or complete EMT, yet the mechanisms enabling cluster formation remain poorly understood. Using an integrated computational–experimental approach, we examine the role of Numb—an inhibitor of Notch intercellular signalling—in mediating EMT and clusters formation. We show via an mathematical model that Numb inhibits a full EMT by stabilizing a hybrid E/M phenotype. Consistent with this observation, knockdown of Numb in stable hybrid E/M cells H1975 results in a full EMT, thereby showing that Numb acts as a brake for a full EMT and thus behaves as a ‘phenotypic stability factor' by modulating Notch-driven EMT. By generalizing the mathematical model to a multi-cell level, Numb is predicted to alter the balance of hybrid E/M versus mesenchymal cells in clusters, potentially resulting in a higher tumour-initiation ability. Finally, Numb correlates with a worse survival in multiple independent lung and ovarian cancer datasets, hence confirming its relationship with increased cancer aggressiveness.


2021 ◽  
pp. 096032712110061
Author(s):  
D Cao ◽  
L Chu ◽  
Z Xu ◽  
J Gong ◽  
R Deng ◽  
...  

Background: Visfatin acts as an oncogenic factor in numerous tumors through a variety of cellular processes. Visfatin has been revealed to promote cell migration and invasion in gastric cancer (GC). Snai1 is a well-known regulator of EMT process in cancers. However, the relationship between visfatin and snai1 in GC remains unclear. The current study aimed to explore the role of visfatin in GC. Methods: The RT-qPCR and western blot analysis were used to measure RNA and protein levels, respectively. The cell migration and invasion were tested by Trans-well assays and western blot analysis. Results: Visfatin showed upregulation in GC cells. Additionally, Visfatin with increasing concentration facilitated epithelial-mesenchymal transition (EMT) process by increasing E-cadherin and reducing N-cadherin and Vimentin protein levels in GC cells. Moreover, endogenous overexpression and knockdown of visfatin promoted and inhibited migratory and invasive abilities of GC cells, respectively. Then, we found that snai1 protein level was positively regulated by visfatin in GC cells. In addition, visfatin activated the NF-κB signaling to modulate snai1 protein expression. Furthermore, the silencing of snai1 counteracted the promotive impact of visfatin on cell migration, invasion and EMT process in GC. Conclusion: Visfatin facilitates cell migration, invasion and EMT process by targeting snai1 via the NF-κB signaling, which provides a potential insight for the treatment of GC.


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