scholarly journals Annexin A6 and NPC1 regulate LDL-inducible cell migration and distribution of focal adhesions

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Jaimy Jose ◽  
Monira Hoque ◽  
Johanna Engel ◽  
Syed S. Beevi ◽  
Mohamed Wahba ◽  
...  

AbstractCholesterol is considered indispensable for cell motility, but how physiological cholesterol pools enable cells to move forward remains to be clarified. The majority of cells obtain cholesterol from the uptake of Low-Density lipoproteins (LDL) and here we demonstrate that LDL stimulates A431 squamous epithelial carcinoma and Chinese hamster ovary (CHO) cell migration and invasion. LDL also potentiated epidermal growth factor (EGF) -stimulated A431 cell migration as well as A431 invasion in 3-dimensional environments, using organotypic assays. Blocking cholesterol export from late endosomes (LE), using Niemann Pick Type C1 (NPC1) mutant cells, pharmacological NPC1 inhibition or overexpression of the annexin A6 (AnxA6) scaffold protein, compromised LDL-inducible migration and invasion. Nevertheless, NPC1 mutant cells established focal adhesions (FA) that contain activated focal adhesion kinase (pY397FAK, pY861FAK), vinculin and paxillin. Compared to controls, NPC1 mutants display increased FA numbers throughout the cell body, but lack LDL-inducible FA formation at cell edges. Strikingly, AnxA6 depletion in NPC1 mutant cells, which restores late endosomal cholesterol export in these cells, increases their cell motility and association of the cholesterol biosensor D4H with active FAK at cell edges, indicating that AnxA6-regulated transport routes contribute to cholesterol delivery to FA structures, thereby improving NPC1 mutant cell migratory behaviour.

2019 ◽  
Vol 77 (14) ◽  
pp. 2839-2857 ◽  
Author(s):  
Elsa Meneses-Salas ◽  
Ana García-Melero ◽  
Kristiina Kanerva ◽  
Patricia Blanco-Muñoz ◽  
Frederic Morales-Paytuvi ◽  
...  

Abstract Cholesterol accumulation in late endosomes is a prevailing phenotype of Niemann-Pick type C1 (NPC1) mutant cells. Likewise, annexin A6 (AnxA6) overexpression induces a phenotype reminiscent of NPC1 mutant cells. Here, we demonstrate that this cellular cholesterol imbalance is due to AnxA6 promoting Rab7 inactivation via TBC1D15, a Rab7-GAP. In NPC1 mutant cells, AnxA6 depletion and eventual Rab7 activation was associated with peripheral distribution and increased mobility of late endosomes. This was accompanied by an enhanced lipid accumulation in lipid droplets in an acyl-CoA:cholesterol acyltransferase (ACAT)-dependent manner. Moreover, in AnxA6-deficient NPC1 mutant cells, Rab7-mediated rescue of late endosome-cholesterol export required the StAR-related lipid transfer domain-3 (StARD3) protein. Electron microscopy revealed a significant increase of membrane contact sites (MCS) between late endosomes and ER in NPC1 mutant cells lacking AnxA6, suggesting late endosome-cholesterol transfer to the ER via Rab7 and StARD3-dependent MCS formation. This study identifies AnxA6 as a novel gatekeeper that controls cellular distribution of late endosome-cholesterol via regulation of a Rab7-GAP and MCS formation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria De Luca ◽  
Roberta Romano ◽  
Cecilia Bucci

AbstractV-ATPase is a large multi-subunit complex that regulates acidity of intracellular compartments and of extracellular environment. V-ATPase consists of several subunits that drive specific regulatory mechanisms. The V1G1 subunit, a component of the peripheral stalk of the pump, controls localization and activation of the pump on late endosomes and lysosomes by interacting with RILP and RAB7. Deregulation of some subunits of the pump has been related to tumor invasion and metastasis formation in breast cancer. We observed a decrease of V1G1 and RAB7 in highly invasive breast cancer cells, suggesting a key role of these proteins in controlling cancer progression. Moreover, in MDA-MB-231 cells, modulation of V1G1 affected cell migration and matrix metalloproteinase activation in vitro, processes important for tumor formation and dissemination. In these cells, characterized by high expression of EGFR, we demonstrated that V1G1 modulates EGFR stability and the EGFR downstream signaling pathways that control several factors required for cell motility, among which RAC1 and cofilin. In addition, we showed a key role of V1G1 in the biogenesis of endosomes and lysosomes. Altogether, our data describe a new molecular mechanism, controlled by V1G1, required for cell motility and that promotes breast cancer tumorigenesis.


2021 ◽  
Author(s):  
Erik S Linklater ◽  
Emily Duncan ◽  
Ke Jun Han ◽  
Algirdas Kaupinis ◽  
Mindaugas Valius ◽  
...  

Rab40b is a SOCS box containing protein that regulates the secretion of MMPs to facilitate extracellular matrix remodeling during cell migration. Here we show that Rab40b interacts with Cullin5 via the Rab40b SOCS domain. We demonstrate that loss of Rab40b/Cullin5 binding decreases cell motility and invasive potential, and show that defective cell migration and invasion stem from alteration to the actin cytoskeleton, leading to decreased invadopodia formation, decreased actin dynamics at the leading edge, and an increase in stress fibers. We also show that these stress fibers anchor at less dynamic, more stable focal adhesions. Mechanistically, changes in the cytoskeleton and focal adhesion dynamics are mediated in part by EPLIN, which we demonstrate to be a binding partner of Rab40b and a target for Rab40b/Cullin5 dependent localized ubiquitylation and degradation. Thus, we propose a model where the Rab40b/Cullin5 dependent ubiquitylation regulates EPLIN localization to promote cell migration and invasion by altering focal adhesion and cytoskeletal dynamics.


1982 ◽  
Vol 2 (5) ◽  
pp. 535-544
Author(s):  
B Ray ◽  
H C Wu

Chinese hamster ovary mutants simultaneously resistant to ricin and Pseudomonas toxin have been isolated. Two mutant cell lines (4-10 and 11-2) were found to retain normal levels of binding of both ricin and Pseudomonas toxin. They were defective in the internalization of [125I]ricin into the mutant cells, as measured by both a biochemical assay for ricin internalization and electron microscopic autoradiographic studies. Although pretreatment of Chinese hamster ovary cells with a Na+/K+ ionophore, nigericin, resulted in an enhancement of the cytotoxicities of ricin and Pseudomonas toxin in the wild-type Chinese hamster ovary cells, preculture of the mutant cells did not alter the susceptibility of the mutant cells to either toxin. These results provide further evidence that there is a common step in the internalization process for ricin and Pseudomonas toxin.


2014 ◽  
Vol 465 (1) ◽  
pp. 89-101 ◽  
Author(s):  
Fauzia Chaudhary ◽  
Robert Lucito ◽  
Nicholas K. Tonks

We determined a mechanism by which loss of the metastasis suppressor MIM (Missing in Metastasis) enhanced cell migration and invasion. This defined a signature of signalling events that may be exploited for selective targeting of MIM-deficient metastatic tumours.


1999 ◽  
Vol 146 (2) ◽  
pp. 389-404 ◽  
Author(s):  
Jianguo Gu ◽  
Masahito Tamura ◽  
Roumen Pankov ◽  
Erik H.J. Danen ◽  
Takahisa Takino ◽  
...  

Cell migration is modulated by regulatory molecules such as growth factors, oncogenes, and the tumor suppressor PTEN. We previously described inhibition of cell migration by PTEN and restoration of motility by focal adhesion kinase (FAK) and p130 Crk-associated substrate (p130Cas). We now report a novel pathway regulating random cell motility involving Shc and mitogen-activated protein (MAP) kinase, which is downmodulated by PTEN and additive to a FAK pathway regulating directional migration. Overexpression of Shc or constitutively activated MEK1 in PTEN- reconstituted U87-MG cells stimulated integrin- mediated MAP kinase activation and cell migration. Conversely, overexpression of dominant negative Shc inhibited cell migration; Akt appeared uninvolved. PTEN directly dephosphorylated Shc. The migration induced by FAK or p130Cas was directionally persistent and involved extensive organization of actin microfilaments and focal adhesions. In contrast, Shc or MEK1 induced a random type of motility associated with less actin cytoskeletal and focal adhesion organization. These results identify two distinct, additive pathways regulating cell migration that are downregulated by tumor suppressor PTEN: one involves Shc, a MAP kinase pathway, and random migration, whereas the other involves FAK, p130Cas, more extensive actin cytoskeletal organization, focal contacts, and directionally persistent cell motility. Integration of these pathways provides an intracellular mechanism for regulating the speed and the directionality of cell migration.


2004 ◽  
Vol 164 (4) ◽  
pp. 547-556 ◽  
Author(s):  
Krishnamurthy Malathi ◽  
Katsumi Higaki ◽  
Arthur H. Tinkelenberg ◽  
Dina A. Balderes ◽  
Dorca Almanzar-Paramio ◽  
...  

Lipid movement between organelles is a critical component of eukaryotic membrane homeostasis. Niemann Pick type C (NP-C) disease is a fatal neurodegenerative disorder typified by lysosomal accumulation of cholesterol and sphingolipids. Expression of yeast NP-C–related gene 1 (NCR1), the orthologue of the human NP-C gene 1 (NPC1) defective in the disease, in Chinese hamster ovary NPC1 mutant cells suppressed lipid accumulation. Deletion of NCR1, encoding a transmembrane glycoprotein predominantly residing in the vacuole of normal yeast, gave no phenotype. However, a dominant mutation in the putative sterol-sensing domain of Ncr1p conferred temperature and polyene antibiotic sensitivity without changes in sterol metabolism. Instead, the mutant cells were resistant to inhibitors of sphingolipid biosynthesis and super sensitive to sphingosine and C2-ceramide. Moreover, plasma membrane sphingolipids accumulated and redistributed to the vacuole and other subcellular membranes of the mutant cells. We propose that the primordial function of these proteins is to recycle sphingolipids and that defects in this process in higher eukaryotes secondarily result in cholesterol accumulation.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Julia Damiano-Guercio ◽  
Laëtitia Kurzawa ◽  
Jan Mueller ◽  
Georgi Dimchev ◽  
Matthias Schaks ◽  
...  

Cell migration entails networks and bundles of actin filaments termed lamellipodia and microspikes or filopodia, respectively, as well as focal adhesions, all of which recruit Ena/VASP family members hitherto thought to antagonize efficient cell motility. However, we find these proteins to act as positive regulators of migration in different murine cell lines. CRISPR/Cas9-mediated loss of Ena/VASP proteins reduced lamellipodial actin assembly and perturbed lamellipodial architecture, as evidenced by changed network geometry as well as reduction of filament length and number that was accompanied by abnormal Arp2/3 complex and heterodimeric capping protein accumulation. Loss of Ena/VASP function also abolished the formation of microspikes normally embedded in lamellipodia, but not of filopodia capable of emanating without lamellipodia. Ena/VASP-deficiency also impaired integrin-mediated adhesion accompanied by reduced traction forces exerted through these structures. Our data thus uncover novel Ena/VASP functions of these actin polymerases that are fully consistent with their promotion of cell migration.


2019 ◽  
Vol 16 (152) ◽  
pp. 20180934
Author(s):  
Takumi Hiraiwa ◽  
Takahiro G. Yamada ◽  
Norihisa Miki ◽  
Akira Funahashi ◽  
Noriko Hiroi

Neuroblastoma is the most common solid tumour of childhood, and it metastasizes to distant organs. However, the mechanism of metastasis, which generally depends on the cell motility of the neuroblastoma, remains unclear. In many solid tumours, it has been reported that shear stress promotes metastasis. Here, we investigated the relationship between shear stress and cell motility in the MYCN-amplified human neuroblastoma cell line IMR32, using a microfluidic device. We confirmed that most of the cells migrated downstream, and cell motility increased dramatically when the cells were exposed to a shear stress of 0.4 Pa, equivalent to that expected in vivo . We observed that the morphological features of focal adhesion were changed under a shear stress of 0.4 Pa. We also investigated the relationship between malignancy and the motility of IMR32 cells under shear stress. Decreasing the expression of MYCN in IMR32 cells via siRNA transfection inhibited cell motility by a shear stress of 0.4 Pa. These results suggest that MYCN-amplified neuroblastoma cells under high shear stress migrate to distant organs due to high cell motility, allowing cell migration to lymphatic vessels and venules.


Cancers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3018
Author(s):  
Gaia Giuntini ◽  
Sara Monaci ◽  
Ylenia Cau ◽  
Mattia Mori ◽  
Antonella Naldini ◽  
...  

Background: Intratumoral hypoxia contributes to cancer progression and poor prognosis. Carbonic anhydrases IX (CAIX) and XII (CAXII) play pivotal roles in tumor cell adaptation and survival, as aberrant Hedgehog (Hh) pathway does. In malignant melanoma both features have been investigated for years, but they have not been correlated before and/or identified as a potential pharmacological target. Here, for the first time, we demonstrated that malignant melanoma cell motility was impaired by targeting CAXII via either CAs inhibitors or through the inhibition of the Hh pathway. Methods: We tested cell motility in three melanoma cell lines (WM-35, SK-MEL28, and A375), with different invasiveness capabilities. To this end we performed a scratch assay in the presence of the smoothened (SMO) antagonist cyclopamine (cyclo) or CAs inhibitors under normoxia or hypoxia. Then, we analyzed the invasiveness potential in the cell lines which were more affected by cyclo and CAs inhibitors (SK-MEL28 and A375). Western blot was employed to assess the expression of the hypoxia inducible factor 1α, CAXII, and FAK phosphorylation. Immunofluorescence staining was performed to verify the blockade of CAXII expression. Results: Hh inhibition reduced melanoma cell migration and CAXII expression under both normoxic and hypoxic conditions. Interestingly, basal CAXII expression was higher in the two more aggressive melanoma cell lines. Finally, a direct CAXII blockade impaired melanoma cell migration and invasion under hypoxia. This was associated with a decrease of FAK phosphorylation and metalloprotease activities. Conclusions: CAXII may be used as a target for melanoma treatment not only through its direct inhibition, but also through Hh blockade.


Sign in / Sign up

Export Citation Format

Share Document