489 research outputs found
Assessment of apoptosis in human breast tissue using an antibody against the active form of caspase 3: relation to tumour histopathological characteristics
Apoptosis is of important significance in the pathogenesis of cancer. Many methods are available for the measurement of apoptosis but the ‘gold standard’ is to identify apoptotic cells by their morphological features using microscopy. Caspase 3 is a cytosolic enzyme that is activated only in cells committed to undergo apoptosis. The activation of caspase 3 precedes the development of the classical morphological features of apoptosis. Using immunohistochemistry with an antibody against the active form of caspase 3, the apoptotic index (AI) was measured in 116 samples of human breast tissue (22 normal/benign and 94 invasive carcinomas). The AI obtained by measuring caspase activation has a strong correlation with the AI derived by morphological assessment (r = 0.736, P < 0.01). The AI is higher in the invasive group than in the benign group (P = 0.008), and in invasive cancer high AI is associated with high tumour grade (P = 0.013), positive node status (P < 0.001) and negative steroid receptor status (P = 0.001 for ER; P = 0.004 for PR). No significant association is observed between AI and tumour size. Measurement of apoptosis by immunohistochemistry using an antibody against the active form of caspase 3 is therefore reliable and correlates strongly with morphological assessment. © 2001 Cancer Research Campaign  http://www.bjcancer.co
Control of mammary epithelial differentiation: basement membrane induces tissue-specific gene expression in the absence of cell-cell interaction and morphological polarity.
Variants of BALB/c 3T3 cells lacking complex gangliosides retain a fibronectin matrix and spread normally on fibronectin-coated substrates.
Overexpression of leucocyte common antigen (LAR) P-subunit in thyroid carcinomas
Protein tyrosine phosphatase (PTPase) dephosphorylation and protein tyrosine kinase (PTKs) phosphorylation of key signal transduction proteins may be regulated by extracellular signals, making PTPases important in the regulation of cell proliferation. Leucocyte common antigen (LAR), a receptor-like PTPase, consists of E-subunit, containing the cell adhesion molecule-like receptor region, and P-subunit specific for a short segment of the extracellular region, the transmembrane peptide, and two cytoplasmic PTPase domains. We produced a monoclonal antibody against the LAR P-subunit for immunohistochemical screening of LAR expression in normal and tumourous tissues. Gliomas and gastric, colorectal, lung, breast and prostate cancers showed weak and relatively infrequent expression. Intense and diffuse expression, however, was detected in 95% (227 out of 239) of thyroid carcinomas, but only 12% (22 out of 128) of adenomas and no cases of benign thyroid disease were immunopositive. In contrast to broad staining in carcinomas, LAR expression in thyroid adenomas was often found in small focal or locally invasive areas. Western blot analysis similarly detected LAR P-subunit protein in thyroid carcinomas, but not in normal tissues. We believe this to be the first demonstration of LAR overexpression in thyroid carcinoma and may help to elucidate the role of PTPases in the development of malignancy
Living alone is a risk factor for mortality in men but not women from the general population: a prospective cohort study
During the past decades a rising trend of living alone can be observed in the population especially in urban areas. Living alone is considered a psychosocial risk factor. We studied the relationship between living alone, cardiovascular risk factors and mortality. We analysed data from the population-based MONICA/KORA cohort study including 3596 men and 3420 women of at least one of three surveys carried out between 1984 and 1995 in the region of Augsburg, Germany. They were between 45 and 74 years old and were followed-up until 31 December 2002. During follow-up 811 men and 388 women died. Cox proportional hazards analysis was used to examine the association between living alone and mortality
Exploring hypotheses of the actions of TGF-beta 1 in epidermal wound healing using a 3D computational multiscale model of the human epidermis
In vivo and in vitro studies give a paradoxical picture of the actions of the key regulatory factor TGF-beta 1 in epidermal wound healing with it stimulating migration of keratinocytes but also inhibiting their proliferation. To try to reconcile these into an easily visualized 3D model of wound healing amenable for experimentation by cell biologists, a multiscale model of the formation of a 3D skin epithelium was established with TGF-beta 1 literature-derived rule sets and equations embedded within it. At the cellular level, an agent-based bottom-up model that focuses on individual interacting units ( keratinocytes) was used. This was based on literature-derived rules governing keratinocyte behavior and keratinocyte/ECM interactions. The selection of these rule sets is described in detail in this paper. The agent-based model was then linked with a subcellular model of TGF-beta 1 production and its action on keratinocytes simulated with a complex pathway simulator. This multiscale model can be run at a cellular level only or at a combined cellular/subcellular level. It was then initially challenged ( by wounding) to investigate the behavior of keratinocytes in wound healing at the cellular level. To investigate the possible actions of TGF-beta 1, several hypotheses were then explored by deliberately manipulating some of these rule sets at subcellular levels. This exercise readily eliminated some hypotheses and identified a sequence of spatial-temporal actions of TGF-beta 1 for normal successful wound healing in an easy-to-follow 3D model. We suggest this multiscale model offers a valuable, easy-to-visualize aid to our understanding of the actions of this key regulator in wound healing, and provides a model that can now be used to explore pathologies of wound healing
Neuropilin-1 antagonism in human carcinoma cells inhibits migration and enhances chemosensitivity
BACKGROUND: Neuropilin-1 (NRP1) is a non-tyrosine kinase receptor for vascular endothelial growth factor (VEGF) recently implicated in tumour functions.METHODS: In this study we used a specific antagonist of VEGF binding to the NRP1 b1 domain, EG3287, to investigate the functional roles of NRP1 in human carcinoma cell lines, non-small-cell lung A549, kidney ACHN, and prostate DU145 cells expressing NRP1, and the underlying mechanisms involved.RESULTS: EG3287 potently displaced the specific binding of VEGF to NRP1 in carcinoma cell lines and significantly inhibited the migration of A549 and ACHN cells. Neuropilin-1 downregulation by siRNA also decreased cell migration. EG3287 reduced the adhesion of A549 and ACHN cells to extracellular matrix (ECM), and enhanced the anti-adhesive effects of a beta 1-integrin function-blocking antibody. EG3287 increased the cytotoxic effects of the chemotherapeutic agents 5-FU, paclitaxel, or cisplatin on A549 and DU145 cells, through inhibition of integrin-dependent cell interaction with the ECM.CONCLUSIONS: These findings indicate that NRP1 is important for tumour cell migration and adhesion, and that NRP1 antagonism enhances chemosensitivity, at least in part, by interfering with integrin-dependent survival pathways. A major implication of this study is that therapeutic strategies targeting NRP1 in tumour cells may be particularly useful in combination with other drugs for combating tumour survival, growth, and metastatic spread independently of an antiangiogenic effect of blocking NRP1. British Journal of Cancer (2010) 102, 541-552. doi:10.1038/sj.bjc.6605539 www.bjcancer.com Published online 19 January 2010 (C) 2010 Cancer Research U
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