Spreading of non-transformed and transformed cells

Vasiliev, J. M.

doi:10.1016/0304-419x(84)90006-4

Cited by 55 publications

(42 citation statements)

References 313 publications

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“…rIESIVE interactions of cells with the extracellular matrix and their reversal are critical events for morphogenetic movements during embryonic development and for cancer cell invasion during metastasis (30,49). The molecular structures at the sites where cultured cells contact each other and the growth substratum are thus of great interest.…”

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confidence: 99%

Ultrastructural localization of plasma membrane-associated urokinase-type plasminogen activator at focal contacts.

Pöllänen

Hedman

Nielsen

et al. 1988

The Journal of Cell Biology

297

117

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Abstract.We have recently shown that urokinase-type plasminogen activator (u-PA) and plasminogen activator inhibitor type 1 are both found extracellularly beneath cultured human skin fibroblasts and HT-1080 sarcoma cells, but in distinct localizations. Here, the ultrastructural distribution of u-PA was studied using immunoferritin electron microscopy. In HT-1080 cells, u-PA on the extracellular aspect of the plasma membrane was detected at sites of direct contact of the cell with the growth substratum beneath all parts of the ventral cell surface. The ferritin-labeled adhesion plaques, which were enriched in submembraneous microfilaments, were frequently seen at the leading lamellae of the cells as well as in lamellipodia and microspikes. Besides the cell-substratum adhesion plaques, ferritin label was detected at cell-cell contact sites. Double-label immunofluorescence showed a striking colocalization of u-PA and vinculin in both HT-1080 cells and WI-38 lung fibroblasts, which is consistent with u-PA being a focal contact component. The u-PAcontaining focal contacts of WI-38 cells had no direct codistribution with fibronectin fibrils. In WI-38 cells made stationary by cultivation in a medium containing 0.5 % FCS, vinculin plaques became highly elongated and more centrally located, whereas u-PA immunolabel disappeared from such focal adhesions. These findings show that plasma membrane-associated u-PA is an intrinsic component of focal contacts, where, we propose, it enables directional proteolysis for cell migration and invasion. rIESIVE interactions of cells with the extracellular matrix and their reversal are critical events for morphogenetic movements during embryonic development and for cancer cell invasion during metastasis (30, 49). The molecular structures at the sites where cultured cells contact each other and the growth substratum are thus of great interest. Focal contacts, the sites of closest cell-substratum apposition, can be visualized either by electron microscopy (1) or by interference reflection microscopy (23). Focal contacts are localized at the termini of actin-containing microfilament bundles, and contain vinculin (7, 19) and talin (6) on the cytoplasmic side, but apparently do not have fibronectin on the extracellular side (9). The so-called close contacts exhibit a greater substrate separation distance, do not contain vinculin, and probably represent a more labile type of contact (23). A third kind of substrate adhesion site termed the fibronexus (42) or extracellular matrix contact site (9) is characteristic of well-spread and stationary fibroblasts. It features a codistribution of fibronectin, its plasma membrane receptor, actin, vinculin, and alpha-actinin throughout the entire contact site and is located at central regions of the cell rather than at its margins (11,15). Fibronexuses show very close transmembrane associations of actin microfilaments and fibronectin fibrils (42,43).

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mentioning

confidence: 99%

Ultrastructural localization of plasma membrane-associated urokinase-type plasminogen activator at focal contacts.

Pöllänen

Hedman

Nielsen

et al. 1988

The Journal of Cell Biology

297

117

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“…One of the most consistent characteristics of cells infected with transforming viruses, cells treated with tumor-promoting phorbol esters, and cells stimulated with growth factors, is the disorganization of stress fibers (for a review see reference 33). Since all of these agents stimulate various kinds of protein kinases (6,8,9,12,17,25), it is possible that a common pathway is followed during the disruption process.…”

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Reorganization of alpha-actinin and vinculin induced by a phorbol ester in living cells.

Meigs¹,

Wang²

1986

The Journal of Cell Biology

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Abstract. We have used fluorescent analogue cytochemistry, image intensification, and digital image processing to examine the redistribution of alphaactinin and vinculin in living cultured African green monkey kidney (BSC-1) cells treated with the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA). Before treatment, microinjected alpha-actinin shows characteristic distribution along stress fibers and at adhesion plaques; vinculin is localized predominantly at adhesion plaques. Soon after the addition of TPA, highly dynamic membrane ruffles begin to form. These incorporate a large amount of alpha-actinin but little vinculin. Alpha-actinin is subsequently depleted, more or less uniformly, from stress fibers. Disrupted stress fibers often fragment into aggregates and move into the perinuclear region. Careful analyses of fluorescence intensity distribution indicate that alphaactinin is depleted more rapidly from adhesion plaques than from stress fibers. Furthermore, the depletion of alpha-actinin from adhesion plaques is also faster than either the depletion of vinculin or the disappearance of focal contacts. These observations indicate that TPA may initiate disruption of stress fibers by interfering with a link between alpha-actinin and vinculin, causing alpha-actinin to be preferentially depleted from adhesion plaques. MANY cultured nonmuscle cells contain a well-organized set of stress fibers, which are large bundles of actin filaments associated with various accessory proteins such as alpha-actinin, myosin, and tropomyosin (for a review see reference 22). One of the most consistent characteristics of cells infected with transforming viruses, cells treated with tumor-promoting phorbol esters, and cells stimulated with growth factors, is the disorganization of stress fibers (for a review see reference 33). Since all of these agents stimulate various kinds of protein kinases (6,8,9,12,17,25), it is possible that a common pathway is followed during the disruption process.The reorganization of actin and vinculin induced by the tumor-promoting phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA),~ has recently been studied using fluorescent phalloidin staining, immunofluorescence, and electron microscopy. Shortly after treatment, large actin-containing rufties appear and stress fibers start to disappear from the cytoplasm (26, 30). Vinculin can be detected at the ends of stress fibers, where adhesion plaques are located, during the early stage of disruption. At steady state, the cell contains prominent ruffles and numerous aggregates of actin and vinculin. Although these studies have shown the dramatic effects of Abbreviations used in this paper." DMSO, dimethyl sulfoxide; FITC, fluorescein isothiocyanate; IATR, iodoacetamidotetramethylrhodamine; IRM, interference reflection microscopy; 4-alpha-PDD, 4-alpha-phorbol 12,13-didecanoate: TPA, 12-O-tetradecanoylphorbol-13-acetate.TPA, the actual process of structural reorganization can only be speculated upon since most observations were performed on different, ...

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“…It is well known that fibroblasts, when fully spread, usually have straight bundles of actin microfilaments (stress fibers) running through the cell body approximately parallel to the body axis and microtubules running from perinuclear part toward the cell periphery. However, in the course of spreading on the plane substrate, fibroblasts usually pass through a transitory phase when they have discoid shape and a circular microfilament bundle (the so-called radial stage) (Vasiliev, 1985). Polarized, fully spread fibroblasts can temporarily acquire discoid, epithelioid shape when treated by drugs that disorganize microtubules such as Taxol ® (Pletjushkina et al, 1994) or a combination of drugs inhibiting Rho kinase and drugs that depolymerize microtubules (Omelchenko et al, 2002).…”

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confidence: 99%