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排序方式: 共有218条查询结果,搜索用时 15 毫秒
21.
Keratinocytes and other epithelial cells express two receptors for the basement membrane (BM) extracellular matrix component laminin-5 (Ln-5), integrins alpha 3 beta 1 and alpha 6 beta 4. While alpha 3 beta 1 mediates adhesion, spreading, and migration (Kreidberg, J.A. 2000. Curr. Opin. Cell Biol. 12:548--553), alpha 6 beta 4 is involved in BM anchorage via hemidesmosomes (Borradori, L., and A. Sonnenberg. 1999. J. Invest. Dermatol. 112:411--418). We investigated a possible regulatory interplay between alpha 3 beta 1 and alpha 6 beta 4 in cell motility using HaCaT keratinocytes as a model. We found that alpha 6 beta 4 antibodies inhibit alpha 3 beta 1-mediated migration on Ln-5, but only when migration is haptotactic (i.e., spontaneous or stimulated by alpha 3 beta 1 activation), and not when chemotactic (i.e., triggered by epidermal growth factor receptor). Inhibition of migration by alpha 6 beta 4 depends upon phosphoinositide 3-kinase (PI3-K) since it is abolished by PI3-K blockers and by dominant-negative PI3-K, and constitutively active PI3-K prevents haptotaxis. In HaCaT cells incubated with anti-alpha 6 beta 4 antibodies, activation of PI3-K is mediated by alpha 6 beta 4-associated erbB-2, as indicated by erbB-2 autophosphorylation and erbB-2/p85 PI3-K coprecipitation. Furthermore, dominant-negative erbB-2 abolishes inhibition of haptotaxis by anti-alpha 6 beta 4 antibodies. These results support a model whereby (a) haptotactic cell migration on Ln-5 is regulated by concerted action of alpha 3beta 1 and alpha 6 beta 4 integrins, (b) alpha 6 beta 4-associated erbB-2 and PI3-K negatively affect haptotaxis, and (c) chemotaxis on Ln-5 is not affected by alpha 6 beta 4 antibodies and may require PI3-K activity. This model could be of general relevance to motility of epithelial cells in contact with BM. 相似文献
22.
Quaranta M Coviello M Daniele A Abbate I Durrant LG Paradiso A Schittulli F 《The International journal of biological markers》2004,19(2):109-114
Mucins are an important class of complex glycoproteins expressed by many epithelial cells and their malignant counterparts. The aim of this study was to determine the serum levels of MUC3 and mucin-like carcinoma-associated antigen (MCA) in patients with primary breast cancer and to analyze the possible relationships between these two mucins and the steroid receptor status. The preoperative basal serum levels of MUC3 (ELISA assay with monoclonal antibody 1143/B7) and MCA (EIA assay with anti-MCA mouse monoclonal antibody b-12) were determined in 44 patients with breast cancer while estrogen receptor (ER) and progesterone receptor (PgR) levels were measured by the dextran-coated charcoal method in the cytosol of neoplastic tissue. MUC3 was expressed in 43/44 serum samples while high MCA serum levels were found in 16/44 only; the mean values of both markers did not correlate with menopausal status, tumor size, nodal involvement or ER. The only significant difference observed was a lower median value of MCA in patients with small tumors (T1-T2). No statistically significant correlation between MUC3 and MCA, MUC3 and ER or MCA and ER was observed; a statistically significant direct correlation between MUC3 and PgR+ status and a statistically significant inverse correlation between MCA and PgR+ were observed. Our results suggest that further investigations are necessary to establish whether progesterone can modulate MUC3 and MCA expression in breast cancer. 相似文献
23.
Conti A Giuffrida MG Napolitano L Quaranta S Bertino E Coscia A Costa S Fabris C 《The Journal of nutritional biochemistry》2000,11(6):332-337
The presence of foreign proteins in human milk after the ingestion of bovine dairy products is thought to be one of the possible causes of allergic sensitization in exclusively breast-fed predisposed infants. The immunologic determination of bovine beta-lactoglobulin (LG) concentration in human milk has been reported by several researchers, but the results are conflicting. Moreover, a strong cross-reactivity between antibodies to bovine beta-LG and human milk proteins and peptides was reported, throwing doubt on the reliability of radioimmunoassay and enzyme-linked immunosorbent assay detection and quantification assays for bovine beta-LG in human milk. Thus, the goal of this study was to isolate human milk peptides with a molecular mass >or= 1,000 Da cross-reactive with antibodies to bovine beta-LG in order to identify possible common epitopes between human and bovine milk proteins. The proteins were first isolated by affinity chromatography with purified polyclonal antibodies to bovine beta-LG, followed by gel filtration fast phase liquid chromatography and reverse phase-high performance liquid chromatography purification of the components specifically bound in the affinity separation step. Affinity-bound peptides were identified by determining their amino acid sequence. All the sequenced peptides belonged to the C-terminal part of human beta-casein, which confirms the cross-reactivity of human milk proteins and peptides with antibodies to bovine beta-LG and allows the identification of possible common epitopes between the two proteins. No bovine beta-LG peptides with a molecular mass >or= 1,000 Da were found in our milk samples from healthy mothers on a diet rich in bovine milk and dairy products. 相似文献
24.
Tumor cell alpha3beta1 integrin and vascular laminin-5 mediate pulmonary arrest and metastasis 下载免费PDF全文
Wang H Fu W Im JH Zhou Z Santoro SA Iyer V DiPersio CM Yu QC Quaranta V Al-Mehdi A Muschel RJ 《The Journal of cell biology》2004,164(6):935-941
Arrest of circulating tumor cells in distant organs is required for hematogenous metastasis, but the tumor cell surface molecules responsible have not been identified. Here, we show that the tumor cell alpha3beta1 integrin makes an important contribution to arrest in the lung and to early colony formation. These analyses indicated that pulmonary arrest does not occur merely due to size restriction, and raised the question of how the tumor cell alpha3beta1 integrin contacts its best-defined ligand, laminin (LN)-5, a basement membrane (BM) component. Further analyses revealed that LN-5 is available to the tumor cell in preexisting patches of exposed BM in the pulmonary vasculature. The early arrest of tumor cells in the pulmonary vasculature through interaction of alpha3beta1 integrin with LN-5 in exposed BM provides both a molecular and a structural basis for cell arrest during pulmonary metastasis. 相似文献
25.
Marino Quaranta 《法国昆虫学会纪事》2013,49(3-4):343-346
A male specimen of Bombus terrestris (L. 1758) showing an intermediate colour between the subspecies xanthopus Kriechbaumer 1870 endemic to Corsica and the subspecies terrestris ubiquitous in the mainland was found within samples collected in 1999 on the Tuscan coast. Hybrid specimens between these subspecies are common on some of the islands of the Tuscan archipelago, while others only have pure populations. The finding is significant as it could signal the spread of the subspecies xanthopus_to the mainland. We consider and discuss the circumstances of the finding. 相似文献
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The deadly feature of cancer, metastasis, requires invasion of cells through basement membranes (BM), which normally act as barriers between tissue compartments. In the case of many epithelially-derived cancers (carcinomas), laminin-332 (Ln-332) is a key component of the BM barrier. This review provides a historical examination of Ln-332 from its discovery through identification of its functions in BM and possible role in carcinomas. Current understanding points to distinct roles for the three Ln-332 subunits (α3, β3, γ2) in cell adhesion, extracellular matrix stability, and cell signaling processes in cancer. Given the large number of studies linking Ln-332 γ2 subunit with cancer prognosis, particular attention is given to the crucial role of this subunit in cancer invasion and to the unanswered questions in this area. 相似文献
28.
Katarzyna A. Rejniak Shizhen E. Wang Nicole S. Bryce Hang Chang Bahram Parvin Jerome Jourquin Lourdes Estrada Joe W. Gray Carlos L. Arteaga Alissa M. Weaver Vito Quaranta Alexander R. A. Anderson 《PLoS computational biology》2010,6(8)
Most tumors arise from epithelial tissues, such as mammary glands and lobules, and their initiation is associated with the disruption of a finely defined epithelial architecture. Progression from intraductal to invasive tumors is related to genetic mutations that occur at a subcellular level but manifest themselves as functional and morphological changes at the cellular and tissue scales, respectively. Elevated proliferation and loss of epithelial polarization are the two most noticeable changes in cell phenotypes during this process. As a result, many three-dimensional cultures of tumorigenic clones show highly aberrant morphologies when compared to regular epithelial monolayers enclosing the hollow lumen (acini). In order to shed light on phenotypic changes associated with tumor cells, we applied the bio-mechanical IBCell model of normal epithelial morphogenesis quantitatively matched to data acquired from the non-tumorigenic human mammary cell line, MCF10A. We then used a high-throughput simulation study to reveal how modifications in model parameters influence changes in the simulated architecture. Three parameters have been considered in our study, which define cell sensitivity to proliferative, apoptotic and cell-ECM adhesive cues. By mapping experimental morphologies of four MCF10A-derived cell lines carrying different oncogenic mutations onto the model parameter space, we identified changes in cellular processes potentially underlying structural modifications of these mutants. As a case study, we focused on MCF10A cells expressing an oncogenic mutant HER2-YVMA to quantitatively assess changes in cell doubling time, cell apoptotic rate, and cell sensitivity to ECM accumulation when compared to the parental non-tumorigenic cell line. By mapping in vitro mutant morphologies onto in silico ones we have generated a means of linking the morphological and molecular scales via computational modeling. Thus, IBCell in combination with 3D acini cultures can form a computational/experimental platform for suggesting the relationship between the histopathology of neoplastic lesions and their underlying molecular defects. 相似文献
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Quaranta MG Vincentini O Felli C Spadaro F Silano M Moricoli D Giordani L Viora M 《PloS one》2011,6(8):e23442