Developmental expression of laminin-5 and HD1 in the intestine: Epithelial to mesenchymal shift for the laminin γ2 chain subunit deposition

Orian-Rousseau, Véronique; Aberdam, Daniel; Fontao, Lionel; Chevalier, Luc; Meneguzzi, Guerríno; Kédinger, Michèle; Simon‐Assmann, Patricia

doi:10.1002/(sici)1097-0177(199605)206:1<12::aid-aja2>3.0.co;2-3

Cited by 60 publications

(47 citation statements)

References 33 publications

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“…While further investigations will be required to clearly answer this question, it is interesting to note that the epithelial basement membrane in the crypt region is negative for laminin-5 in the human small intestine, while it is expressed in the villus basement membrane (39,77), 2 and therefore coincides almost perfectly with the pattern of ␤ 4 A ctd؉ expression. Furthermore, the expression of HD1/plectin has also been reported to be exclusively expressed by villus intestinal cells (77). The repression of laminin-5 and HD1/plectin expression, coupled to the production of an inactive ␣ 6 ␤ 4 A ctdϪ integrin, may thus represent two distinct control mechanisms ensuring that type II hemidesmosomes will not form in undifferentiated intestinal cells.…”

Section: Discussionmentioning

confidence: 97%

Expression of Functionally Distinct Variants of the β4A Integrin Subunit in Relation to the Differentiation State in Human Intestinal Cells

Basora¹,

Herring-Gillam

Boudreau³

et al. 1999

Journal of Biological Chemistry

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Integrins are important mediators of cell-laminin interactions. In the small intestinal epithelium, which consists of spatially separated proliferative and differentiated cell populations located, respectively, in the crypt and on the villus, laminins and laminin-binding integrins are differentially expressed along the cryptvillus axis. One exception to this is the integrin ␣ 6 ␤ 4 , which is thought to be ubiquitously expressed by intestinal cells. However, in this study, a re-evaluation of the ␤ 4 subunit expression with different antibodies revealed that two forms of ␤ 4 exist in the human intestinal epithelium. Furthermore, we show that differentiated enterocytes express a full-length 205-kDa ␤ 4 A subunit, whereas undifferentiated crypt cells express a novel ␤ 4 A subunit that does not contain the COOH-terminal segment of the cytoplasmic domain (␤ 4 A ctd؊ ). This new form was not found to arise from alternative ␤ 4 mRNA splicing. Moreover, we found that these two ␤ 4 A forms can associate into ␣ 6 ␤ 4 A complexes; however, the ␤ 4 A ctd؊ integrin expressed by the undifferentiated crypt cells is not functional for adhesion to laminin-5. Hence, these studies identify a novel ␣ 6 ␤ 4 A ctd؊ integrin expressed in undifferentiated intestinal crypt cells that is functionally distinct.

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Section: Discussionmentioning

confidence: 97%

Expression of Functionally Distinct Variants of the β4A Integrin Subunit in Relation to the Differentiation State in Human Intestinal Cells

Basora¹,

Herring-Gillam

Boudreau³

et al. 1999

Journal of Biological Chemistry

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“…Adherent cells were stained with crystal violet, and the dye in each well was solubilized. Background crystal violet staining was subtracted from all the values, and results were determined as an absorbance at 550 nm (52).…”

Section: Methodsmentioning

confidence: 99%

BRCA1 Suppresses Osteopontin-mediated Breast Cancer

El‐Tanani

Campbell

Crowe

et al. 2006

Journal of Biological Chemistry

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BRCA1 is a well described breast cancer susceptibility gene thought to be involved primarily in DNA repair. However, mutation within the BRCA1 transcriptional domain is also implicated in neoplastic transformation of mammary epithelium, but responsible mechanisms are unclear. Here we show in a rat mammary model system that wild type (WT) BRCA1 specifically represses the expression of osteopontin (OPN), a multifunctional estrogen-responsive gene implicated in oncogenic transformation, particularly that of the breast. WT.BRCA1 selectively binds OPN-activating transcription factors estrogen receptor ␣, AP-1, and PEA3, inhibits OPN promoter transactivation, and suppresses OPN mRNA and protein both from an endogenous gene and a relevant model inducible gene. WT.BRCA1 also inhibits OPN-mediated neoplastic transformation characterized by morphology change, anchorage-independent growth, adhesion to fibronectin, and invasion through Matrigel. A mutant BRCA1 allele (Mut.BRCA1) associated with familial breast cancer lacks OPN suppressor effects, binds to WT.BRCA1, and impedes WT.BRCA1 suppression of OPN. Stable transfection of rat breast tumor cell lines with Mut.BRCA1 dramatically up-regulates OPN protein and induces anchorageindependent growth. In human primary breast cancer, BRCA1 mutation is significantly associated with OPN overexpression. Taken together, these data suggest that BRCA1 mutation may confer increased tissue-specific cancer risk, in part by disruption of BRCA1 suppression of OPN gene transcription.

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“…The observations showing its presence is of interest since this laminin has previously been reported only in BMs of stratified epithelia, in association with anchoring filaments of hemidesmosomes. It is noteworthy that true hemidesmosomes are not present in the human small intestinal epithelium (86,87), consistant with the fact that type VII collagen and some of the major hemidesmosomal proteins are lacking (85,88). However, its localization according to an increasing gradient from the upper crypt to the villus tip in the human small intestine (85,86) coincides well with that of two other important components of hemidesmosomes, HD1/plectin (85) and the beta4 integrin subunit (80; Basora et al, submitted).…”

Section: Basement Membrane Compositionmentioning

confidence: 99%

“…It is noteworthy that true hemidesmosomes are not present in the human small intestinal epithelium (86,87), consistant with the fact that type VII collagen and some of the major hemidesmosomal proteins are lacking (85,88). However, its localization according to an increasing gradient from the upper crypt to the villus tip in the human small intestine (85,86) coincides well with that of two other important components of hemidesmosomes, HD1/plectin (85) and the beta4 integrin subunit (80; Basora et al, submitted). The presence of laminin-5, of HD1/plectin, an intermediate protein in the association of the cytoplasmic domain of the beta4 integrin subunit to cytokeratins (32) as well as of the beta4 subunit of alpha6beta4, a receptor for laminin-5 (see below), suggests that early or type II hemidesmosomes can form at the base of villus intestinal cells.…”

Section: Basement Membrane Compositionmentioning

confidence: 99%

Integrins and human intestinal cell functions

Beaulieu¹

1999

Front Biosci

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Developmental expression of laminin-5 and HD1 in the intestine: Epithelial to mesenchymal shift for the laminin γ2 chain subunit deposition

Cited by 60 publications

References 33 publications

Expression of Functionally Distinct Variants of the β4A Integrin Subunit in Relation to the Differentiation State in Human Intestinal Cells

Expression of Functionally Distinct Variants of the β4A Integrin Subunit in Relation to the Differentiation State in Human Intestinal Cells

BRCA1 Suppresses Osteopontin-mediated Breast Cancer

Integrins and human intestinal cell functions

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