Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0001511 (Adhesion)
 5,955 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adhesion of myeloma cells to bone marrow stromal cells is now considered to play a critical role in chemoresistance. However, little is known about the molecular mechanism governing cell adhesion-mediated drug resistance (CAM-DR) of myeloma cells. In this study, we focused our interests on the implication of the Wnt signal in CAM-DR. We first screened the expression of Wnt family in myeloma cell lines and found that Wnt3 was overexpressed in all the myeloma cells examined. KMS-5 and ARH77, which highly expressed Wnt3 protein, tightly adhered to human bone marrow stromal cells, and accumulation of beta-catenin and GTP-bounded RhoA was observed in these myeloma cell lines. Conversely, RPMI8226 and MM1S, which modestly expressed Wnt3 protein, rather weakly adhered to human bone marrow stromal. We then examined the relevance of Wnt3 expression to adhesive property to stromal cells and to CAM-DR of myeloma cells. KMS-5 and ARH-77 exhibited apparent CAM-DR against doxorubicin. This CAM-DR was significantly reduced by anti-integrin beta(1) antibody, anti-integrin alpha(6) antibody and a Wnt-receptor competitor, secreted Frizzled-related protein-1, and Rho kinase inhibitor Y27632, but not by the specific inhibitor of canonical signaling (Dickkopf-1), indicating that Wnt-mediated CAM-DR that is dependent on integrin alpha(6)/beta(1) (VLA-6)-mediated attachment to stromal cells is induced by the Wnt/RhoA/Rho kinase pathway signal. This CAM-DR was also significantly reduced by Wnt3 small interfering RNA transfer to KMS-5. These results indicate that Wnt3 contributes to VLA-6-mediated CAM-DR via the Wnt/RhoA/ROCK pathway of myeloma cells in an autocrine manner. Thus, the Wnt3 signaling pathway could be a promising molecular target to overcome CAM-DR of myeloma cells.
 ...
PMID:Wnt3/RhoA/ROCK signaling pathway is involved in adhesion-mediated drug resistance of multiple myeloma in an autocrine mechanism. 1757 6

Adhesion proteins are responsible for the structural integrity of epithelial tissue and in tumors this integrity is often lost, resulting in a disorganization of the tissue. In the present study the complexity of the invasive front of colon carcinomas was correlated with cell adhesion protein expression and with polymorphisms in their genes. A complexity index was constructed from 32 colon carcinomas using computer-assisted morphometry estimating fractal dimension and tumor cell clusters followed by tree analysis. Immunohistochemical staining of beta-catenin, E-cadherin, occludin and claudin 2 was used for assessment of protein expression. Genetic screening of tissue from the tumor invasion front with laser microdissection was performed using SSCP and DNA sequencing. Adhesion protein distribution was significantly disturbed in most carcinomas. A single mutation in the gene of beta-catenin was found but there was no correlation between protein expression and genetic polymorphism. Nor was there any correlation between the complexity of the invasive border and protein distribution or genetic alterations. The results indicate that the complexity of colon carcinoma invasion is not dependent on genetic derangements in the genes of adhesion proteins or the protein distribution. Rather, aberrations in the function of other proteins related to the adhesive proteins could be responsible.
 ...
PMID:Disturbed expression of E-cadherin, beta-catenin and tight junction proteins in colon carcinoma is unrelated to growth pattern and genetic polymorphisms. 1839 60

Nuclear factor-kappaB (NF-kappaB) has an important role in multiple myeloma (MM) cell pathogenesis in the context of the bone marrow (BM) microenvironment. In NF-kappaB signaling cascades, IkappaB kinase alpha (IKKalpha) and IKKbeta are key molecules that predominantly mediate noncanonical and canonical pathways, respectively. In this study, we examined the biologic sequelae of the inhibition of IKKalpha versus IKKbeta in MM cell lines. All MM cell lines have constitutive canonical NF-kappaB activity, and a subset of MM cell lines shows noncanonical NF-kappaB activity. Adhesion to BM stromal cells further activates both canonical and noncanonical NF-kappaB activity. IKKbeta inhibitor MLN120B blocks canonical pathway and growth of MM cell lines but does not inhibit the noncanonical NF-kappaB pathway. Although IKKalpha knockdown induces significant growth inhibition in the cell lines with both canonical and noncanonical pathways, it does not inhibit NF-kappaB activation. Importantly, IKKalpha down-regulation decreases expression of beta-catenin and aurora-A, which are known to mediate MM cell growth and survival. Finally, IKKbeta inhibitor enhances the growth inhibition triggered by IKKalpha down-regulation in MM cells with both canonical and noncanonical NF-kappaB activity. Combination therapy targeting these kinases therefore represents a promising treatment strategy in MM.
 ...
PMID:Biologic sequelae of I{kappa}B kinase (IKK) inhibition in multiple myeloma: therapeutic implications. 1927 Feb 64

Cryopreserved hepatocytes with good hepatospecific functions upon thawing are important for clinical transplantation and for in vitro drug toxicity testing. However, cryopreservation reduces viability and certain hepatospecific functions, but the most pronounced change is diminished attachment efficiency of hepatocytes. Adhesion of cells to the extracellular matrix and cell-cell contacts are crucial for many aspects of cellular function. These processes are partly mediated and controlled by cellular adhesion molecules. The mechanisms responsible for reduced attachment efficiency of cryopreserved hepatocytes are not well understood. To address this question, we investigated the effect of a new cryopreservation procedure, using wheat proteins (WPs) or mixtures of recombinant forms of wheat freezing tolerance-associated proteins, on the stability of three important adhesion molecules (beta1-integrin, E-cadherin, and beta-catenin). Immunoblot analyses revealed that the levels of beta1-integrin, E-cadherin, and beta-catenin were much lower in cryopreserved rat hepatocytes, when compared to fresh cells. Protein expression of the adhesion molecules was generally lower in cells cryopreserved with DMSO, compared to WPs. Moreover, the stability of the adhesion molecules was not affected by cryopreservation to the same degree, with more pronounced decreases occurring for beta1-integrin (62-74%) > beta-catenin (51-58%) > E-cadherin (21-37%). However, when hepatocytes were cryopreserved with partially purified WPs (SulWPE, AcWPE) or with mixtures of recombinant wheat proteins, there was a clear protective effect against the loss of protein expression of beta1-integrin, E-cadherin, and beta-catenin. Protein expression was only 10-20% lower than that observed in fresh hepatocytes. These findings clearly demonstrate that WPs, and more particularly, partially purified WPs and recombinant wheat proteins, were more efficient for cryopreservation of rat hepatocytes by maintaining good expression of these adhesion molecules. These promising results could lead to a new and improved cryopreservation technology for applications such as clinical transplantation of hepatocytes.
 ...
PMID:Wheat proteins enhance stability and function of adhesion molecules in cryopreserved hepatocytes. 1947 11

Recent research indicates that the leading edge of lamellipodia of myogenic cells (myoblasts and myotubes) contains presumptive fusion sites, yet the mechanisms that render the plasma membrane fusion-competent remain largely unknown. Here we show that dynamic clustering and dispersion of lipid rafts contribute to both cell adhesion and plasma membrane union during myogenic cell fusion. Adhesion-complex proteins including M-cadherin, beta-catenin, and p120-catenin accumulated at the leading edge of lamellipodia, which contains the presumptive fusion sites of the plasma membrane, in a lipid raft-dependent fashion prior to cell contact. In addition, disruption of lipid rafts by cholesterol depletion directly prevented the membrane union of myogenic cell fusion. Time-lapse recording showed that lipid rafts were laterally dispersed from the center of the lamellipodia prior to membrane fusion. Adhesion proteins that had accumulated at lipid rafts were also removed from the presumptive fusion sites when lipid rafts were laterally dispersed. The resultant lipid raft- and adhesion complex-free area at the leading edge fused with the opposing plasma membrane. These results demonstrate a key role for dynamic clustering/dispersion of lipid rafts in establishing fusion-competent sites of the myogenic cell membrane, providing a novel mechanistic insight into the regulation of myogenic cell fusion.
 ...
PMID:Dynamic clustering and dispersion of lipid rafts contribute to fusion competence of myogenic cells. 1961 58


<< Previous 1 2