Multilayering and loss of apical polarity in MDCK cells transformed with viral K-ras.

Schoenenberger, Cora‐Ann; Żuk, Anna; Kendall, Donna; Matlin, Karl S.

doi:10.1083/jcb.112.5.873

Cited by 88 publications

(56 citation statements)

References 66 publications

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“…It is possible that oncogenes need to disrupt cell polarity to induce the proliferation of polarized epithelia. Consistent with this possibility are the observations that the overexpression of oncogenes such as fos 24 , jun 25 and v-k-ras 26 alter the polarity of epithelial cells in culture. Our results indicate that ErbB2 and ErbB1 receptors differ in their ability to disrupt cell polarity in epithelial monolayers.…”

Section: Discussionsupporting

confidence: 67%

ErbB2, but not ErbB1, reinitiates proliferation and induces luminal repopulation in epithelial acini

et al. 2001

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Both ErbB1 and ErbB2 are overexpressed or amplified in breast tumours. To examine the effects of activating ErbB receptors in a context that mimics polarized epithelial cells in vivo, we activated ErbB1 and ErbB2 homodimers in preformed, growth-arrested mammary acini cultured in threedimensional basement membrane gels. Activation of ErbB2, but not that of ErbB1, led to a reinitiation of cell proliferation and altered the properties of mammary acinar structures. These altered structures share several properties with early-stage tumours, including a loss of proliferative suppression, an absence of lumen, retention of the basement membrane and a lack of invasive properties. ErbB2 activation also disrupted tight junctions and the cell polarity of polarized epithelia, whereas ErbB1 activation did not have any effect. Our results indicate that ErbB receptors differ in their ability to induce early stages of mammary carcinogenesis in vitro and this three-dimensional model system can reveal biological activities of oncogenes that cannot be examined in vitro in standard transformation assays.The mammary epithelium of an adult breast is organized into ducts and lobules. The ducts end in a highly branched structure referred to as the terminal ductal lobular unit (TDLU). A TDLU is comprised of multiple individual units referred to as mammary acini. Each acinus has a central lumen, a single layer of polarized luminal epithelial cells surrounded by myoepithelial cells, and a basement membrane.We have previously shown that human mammary epithelial cells (MECs) form acini-like structures containing a single layer of polarized, growth-arrested cells when grown within a matrix rich in laminin and collagen IV (Matrigel, derived from the Englebreth-Holm Swarm (EHS) tumour) 1,2 . The epithelial cells within acini in vivo and in culture have an apico-basal distribution of polarity markers such as ZO-1, E-cadherin and α 6 β 4 integrins. They also deposit collagen IV and secrete sialomucin in their basal and apical surfaces, respectively 1,2 , indicating that the acinar structures formed in culture closely mimic the acini in an adult breast.Early stages of breast cancer (hyperplasia and ductal carcinoma in situ (DCIS)) are characterized by an increased proliferation of epithelial cells, a loss of acinar organization and § Correspondence and requests for materials should be addressed to J.S.B. joan_brugge@hms.harvard.edu. † Present addresses: Cold Spring Harbor Laboratories, Cold Spring Harbor, New York 11724, USA (S.K.M.); Department of Basic Medical Sciences, Purdue University, West Lafayette, Indiana 47907, USA (S.L.)Supplementary information is available on Nature Cell Biology's website (http://cellbio.nature.com) or as paper copy from the London editorial office of Nature Cell Biology. NIH Public Access Author ManuscriptNat Cell Biol. Author manuscript; available in PMC 2010 October 11. filling of the luminal space 3 . However, a lack of acinar organization and the acquisition of invasive behaviour are later events involved...

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Section: Discussionsupporting

confidence: 67%

ErbB2, but not ErbB1, reinitiates proliferation and induces luminal repopulation in epithelial acini

et al. 2001

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“…It is worth noting that when cells are in rapid growth or transformation, the polarity of these cells is usually attenuated or even lost [53,54]. Two special isoforms of Par3 may be involved in proliferation and apoptosis in hepatoma cells through unidentified pathway(s) [11].…”

Section: Intercellular Junctions and Dna Damage Repairmentioning

confidence: 99%

Cell polarity protein Par3 complexes with DNA-PK via Ku70 and regulates DNA double-strand break repair

Fang

Wang

et al. 2007

Cell Res

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“…Our future efforts will focus on this pathway as a potential mechanism for our observations. Schoenenberger et al (1991) and Chen et al (2000) disagreed on the existence of a tight junction leak as a result of Ras transformation. The latter study reported leakiness, whereas the former did not, even though both reported evidence of cellular morphology and polarity changes as a result of the transformation.…”

Section: Resultsmentioning

confidence: 99%

“…Negating the effect of the ras transformation by inhibiting mitogen-activated protein kinase kinase (MEK) 1 re-sulted in translocation of tight junctional proteins to the cell borders, appearance of tight junctional strands in freeze fracture electron microscopy, and dramatic increases of transepithelial electrical resistance (R t ). However, still earlier studies (Schoenenberger et al, 1991), also conducted on MDCK epithelia, reported that although Ras activation resulted in multilayering of cells with partial loss of cell polarity, there was no change in nonelectrolyte flux across the epithelium, and transepithelial resistance was fourfold higher in the ras-transfected cell sheets.…”

Section: Introductionmentioning

confidence: 95%

“…However, still earlier studies (Schoenenberger et al, 1991), also conducted on MDCK epithelia, reported that although Ras activation resulted in multilayering of cells with partial loss of cell polarity, there was no change in nonelectrolyte flux across the epithelium, and transepithelial resistance was fourfold higher in the ras-transfected cell sheets. The specific goals of the present study were to 1) verify the effect of a ras mutation on tight junction permeability in an epithelial model; 2) characterize the nature of the leak in terms of the types of solutes, regarding both size and charge, able to transit the cell layer at increased rates of flux; and 3) determine changes in abundance and subcellular localization of specific tight junction proteins that occur in association with the changes in permeability.…”

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confidence: 95%

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RasMutation Impairs Epithelial Barrier Function to a Wide Range of Nonelectrolytes

Mullin

Leatherman

Valenzano

et al. 2005

MBoC

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Although ras mutations have been shown to affect epithelial architecture and polarity, their role in altering tight junctions remains unclear. Transfection of a valine-12 mutated ras construct into LLC-PK 1 renal epithelia produces leakiness of tight junctions to certain types of solutes. Transepithelial permeability of D-mannitol increases sixfold but transepithelial electrical resistance increases >40%. This indicates decreased paracellular permeability to NaCl but increased permeability to nonelectrolytes. Permeability increases to D-mannitol (M r 182), polyethylene glycol (M r 4000), and 10,000-M r methylated dextran but not to 2,000,000-M r methylated dextran. This implies a "ceiling" on the size of solutes that can cross a ras-mutated epithelial barrier and therefore that the increased permeability is not due to loss of cells or junctions. Although the abundance of claudin-2 declined to undetectable levels in the ras-overexpressing cells compared with vector controls, levels of occludin and claudins 1, 4, and 7 increased. The abundance of claudins-3 and -5 remained unchanged. An increase in extracellular signal-regulated kinase-2 phosphorylation suggests that the downstream effects on the tight junction may be due to changes in the mitogen-activated protein kinase signaling pathway. These selective changes in permeability may influence tumorigenesis by the types of solutes now able to cross the epithelial barrier. INTRODUCTIONMutations in the three closely related ras genes, H-ras, K-ras, and N-ras, are among the most common mutations found in human cancer, reaching 50% in some types of tumors, such as colorectal carcinoma (Forrester et al., 1987;Andreyev et al., 1997Andreyev et al., , 1998Andreyev et al., , 2001). Vogelstein and colleagues have shown that mutations in K-ras occur early in the development of colon carcinomas (Vogelstein et al., 1988). This dominantly acting mutation in ras results in its constitutive activation and the subsequent triggering of its signaling pathway by influencing GTPase activity. It is clear that mutations in ras contribute both to the recurrence of the disease and to decreased survival (Andreyev et al., 1998). It is less clear, however, what the consequences of ras mutations are during the early stages of tumorigenesis. In this regard, one important issue is the effect of Ras activation on epithelial barrier function, perhaps the most basic of all epithelial functions, and a function shared by all epithelial tissues. Ras can exert fundamental effects on epithelial barrier function through the extracellular signal-regulated kinase-mitogen-activated protein (ERK-MAP) kinase pathway or through direct binding to the tight junction-associated protein, AF-6, which binds to ZO-1, which in turn links the tight junction to the actin cytoskeleton. Activated Ras is known to inhibit interaction between the tight junction-associated proteins, AF-6 and ZO-1, with resultant perturbation of intercellular junctions (Yamamoto et al., 1997). Modulation of tight junctions by G proteins in ge...

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Multilayering and loss of apical polarity in MDCK cells transformed with viral K-ras.

Cited by 88 publications

References 66 publications

ErbB2, but not ErbB1, reinitiates proliferation and induces luminal repopulation in epithelial acini

ErbB2, but not ErbB1, reinitiates proliferation and induces luminal repopulation in epithelial acini

Cell polarity protein Par3 complexes with DNA-PK via Ku70 and regulates DNA double-strand break repair

RasMutation Impairs Epithelial Barrier Function to a Wide Range of Nonelectrolytes

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