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Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alterations in the expression or function of molecules that affect cellular adhesion and proliferation are thought to be critical events for tumor progression. Loss of expression of the cell adhesion molecule E-cadherin and increased expression of the epidermal growth factor receptor are two prominent molecular events that are associated with tumorigenesis. The regulation of E-cadherin-dependent cell adhesion by epidermal growth factor (EGF) was therefore examined in the human breast cancer cell line, MDA-MB-468. In this study, changes were observed in the subcellular distribution of components that mediate the cytoplasmic connection between E-cadherin and the actin-based cytoskeleton in response to activation of the EGF receptor. Serum withdrawal activated E-cadherin-dependent cell-cell aggregation in MDA-MB-468 cells, and this treatment stimulated the interaction of actin, alpha-actinin, and vinculin with E-cadherin complexes, despite the absence of alpha-catenin in these cells. By contrast, the co-precipitation of actin with E-cadherin was not detected in several alpha-catenin positive epithelial cell lines. Treatment with EGF inhibited cellular aggregation but did not affect either the levels of E-cadherin or catenin expression nor the association of catenins (beta-catenin, plakoglobin/gamma-catenin, or p120(cas)) with E-cadherin. However, EGF treatment of the MDA-MB-468 cell line dissociated actin, alpha-actinin, and vinculin from the E-cadherin-catenin complex, and this coincided with a robust phosphorylation of beta-catenin, plakoglobin/gamma-catenin, and p120(cas) on tyrosine residues. Furthermore, inactivation of the EGF receptor in serum-treated MDA-MB-468 cells with either a function-blocking antibody or EGF receptor kinase inhibitors mimicked the effects of serum starvation by stimulating both cellular aggregation and assembly of E-cadherin complexes with vinculin and actin. These results demonstrate that the EGF receptor directly regulates cell-cell adhesion through modulation of the interaction of E-cadherin with the actin cytoskeleton and thus substantiates the coordinate role of both of these molecules in tumor progression and metastasis.
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PMID:The epidermal growth factor receptor modulates the interaction of E-cadherin with the actin cytoskeleton. 953 96

Accumulating evidences indicate that p120 catenin, a member of the E-cadherin (E-CD)/catenin adhesion complex, plays a role in tumor invasion. To establish the expression pattern of p120 in breast cancer, we analysed 326 breast tissue biopsies by tissue microarray. Most of the lobular tumors (88%) showed exclusive cytoplasmic localization, and 6% of them also had p120 nuclear staining. Cytoplasmic p120 strongly associated with complete loss of E-CD and beta-catenin not only in lobular carcinoma and its metastases but also in atypical lobular hyperplasias. In the latter, loss of heterozygosity of E-CD gene was also observed. Complete loss of E-CD and cytoplasmic and nuclear p120 staining was also observed in primary lobular cancer cell cultures generated by us. In ductal tumors, by contrast, reduction of p120 and E-CD in membrane was very common (57 and 53%, respectively), whereas cytoplasmic p120 staining was rarely seen. This simultaneous reduction of membranous E-CD and p120 was not associated with increased Src kinase activity. To demonstrate that cytoplasmic p120 localization was a consequence of the absence of E-CD, the endogenous E-CD was re-expressed in MDA-231 cells by 5-Aza-2'-deoxycytidine (5Aza) treatment. After treatment, p120 shifted from the cytoplasm to the membrane, where it colocalized with endogenous E-CD. Additionally, suppressing E-CD expression in Madin-Darby canine kidney cells by stable transfection of the transcriptional repressors Snail, E47 or Slug, provokes p120 cytoplasmic localization and p120 isoform switching. In conclusion, abnormal cytoplasmic and nuclear localization of p120, which are mediated by the absence of E-CD, characteristically occur in the early stages of lobular breast cancer and are maintained during tumor progression to metastasis. Consequently, p120 may be an important mediator of the oncogenic effects derived from E-CD inactivation, including enhanced motility and invasion, in lobular breast cancer.
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PMID:Cytoplasmic localization of p120ctn and E-cadherin loss characterize lobular breast carcinoma from preinvasive to metastatic lesions. 1507 90

P-Cadherin/CDH3 belongs to the family of classic cadherins that are engaged in various cellular activities including motility, invasion, and signaling of tumor cells, in addition to cell adhesion. However, the biological roles of P-cadherin itself are not fully characterized. Based on information derived from a previous genome-wide cDNA microarray analysis of microdissected pancreatic ductal adenocarcinoma (PDAC), we focused on P-cadherin as one of the genes most strongly overexpressed in the great majority of PDACs. To investigate the consequences of overexpression of P-cadherin in terms of pancreatic carcinogenesis and tumor progression, we used a P-cadherin-deficient PDAC cell line, Panc-1, to construct a cell line (Panc1-CDH3) that stably overexpressed P-cadherin. Induction of P-cadherin in Panc1-CDH3 increased the motility of the cancer cells, but a blocking antibody against P-cadherin suppressed the motility in vitro. Overexpression of P-cadherin was strongly associated with cytoplasmic accumulation of one of the catenins, p120ctn, and cadherin switching in PDAC cells. Moreover, P-cadherin-dependent activation of cell motility was associated with activation of Rho GTPases, Rac1 and Cdc42, through accumulation of p120ctn in cytoplasm and cadherin switching. These findings suggest that overexpression of P-cadherin is likely to be related to the biological aggressiveness of PDACs; blocking of P-cadherin activity or its associated signaling could be a novel therapeutic approach for treatment of aggressive pancreatic cancers.
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PMID:Overexpressed P-cadherin/CDH3 promotes motility of pancreatic cancer cells by interacting with p120ctn and activating rho-family GTPases. 1583 38

delta-Catenin, or neural plakophilin-related armadillo protein, is a unique armadillo domain-containing protein in that it is neural-specific and primarily expressed in the brain. However, our recent analysis of the human genome revealed a consistent association of delta-catenin messenger RNA sequences with malignant cells, although the significance of these findings was unclear. In this study, we report that a number of delta-catenin epitopes were expressed in human prostate cancer cells. Western blot and tissue microarray revealed a close association between increased delta-catenin expression and human primary prostatic adenocarcinomas. The analyses of 90 human prostate cancer and 90 benign prostate tissue samples demonstrated that an estimated 85% of prostatic adenocarcinomas showed enhanced delta-catenin immunoreactivity. delta-Catenin expression increased with prognostically significant increased Gleason scores. By analyzing the same tumor cell clusters using consecutive sections, we showed that an increased delta-catenin immunoreactivity was accompanied by the down-regulation and redistribution of E-cadherin and p120ctn, major cell junction proteins whose inactivation is frequently associated with cancer progression. Furthermore, overexpression of delta-catenin in tumorigenic CWR-R1 cells that are derived from human prostate cancer xenograft resulted in reduced immunoreactivity for E-cadherin and p120ctn at the cell-cell junction. This is the first study comparing overexpression of delta-catenin with the E-cadherin/catenin system in cancer and shows that delta-catenin may be intimately involved in regulating E-cadherin/p120ctn cell-cell adhesion in prostate cancer progression.
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PMID:Increased expression of delta-catenin/neural plakophilin-related armadillo protein is associated with the down-regulation and redistribution of E-cadherin and p120ctn in human prostate cancer. 1622 2

p120 catenin is thought to be a key regulator of E-cadherin function and stability, but its role(s) in vivo is poorly understood. To examine these directly, we generated a conditional p120 knockout mouse and targeted p120 ablation to the embryonic salivary gland. Surprisingly, acinar differentiation is completely blocked, resulting in a gland composed entirely of ducts. Moreover, p120 ablation causes E-cadherin deficiency in vivo and severe defects in adhesion, cell polarity, and epithelial morphology. These changes closely phenocopy high-grade intraepithelial neoplasia, a condition that, in humans, typically progresses to invasive cancer. Tumor-like protrusions appear immediately after p120 ablation at e14 and expand into the lumen until shortly after birth, at which time the animals die with completely occluded glands. The data reveal an unexpected role for p120 in salivary acinar development and show that p120 ablation by itself induces effects consistent with a role in tumor progression.
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PMID:Blocked acinar development, E-cadherin reduction, and intraepithelial neoplasia upon ablation of p120-catenin in the mouse salivary gland. 1639 75

The aim of this study was to investigate the relationship between the expression of p120ctn in human lung squamous cell carcinoma, adenocarcinoma and its clinicopathologic significance. The expression of p120ctn in tumors and adjacent normal lung tissues from 143 patients was examined by immunohistochemistry and Western blot. Expression of p120ctn occurs mainly in the cell membrane of normal bronchial mucosa. Abnormal expression of p120ctn, including cytoplasmic and reduced membranous expression, was found in 114 of 143 specimens (79.7%) and was significantly associated with poor differentiation, high TNM stage, and lymph node metastasis (P<0.05 for each) but not with histologic subtype. The Kaplan-Meier survival test revealed that abnormal expression of p120ctn was related to poor survival (P<0.001). A Cox regression analysis revealed that abnormal p120ctn expression was an independent factor in predicting patient survival (P=0.024). Compared with that in normal lung tissues, membranous protein level was lower in tumors (P=0.003). Abnormal expression of p120ctn is associated with tumor progression and poor prognosis in lung squamous cell carcinoma and adenocarcinoma. Reduced expression or even the absence of p120ctn isoform 1 and 3 in tumor cell membranes may be responsible for the abnormal expression of p120ctn that has been found in lung cancer.
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PMID:Abnormal expression and clinicopathologic significance of p120-catenin in lung cancer. 1669 36

Down-regulation of the epithelial cell-cell adhesion molecule E-cadherin is frequently associated with tumor formation and progression. Besides its role in physical cell-cell adhesion, E-cadherin is also thought to be involved in intracellular signaling in normal epithelial cells. In these cells, the Armadillo catenin p120ctn binds to the cytoplasmic domain of E-cadherin and stabilizes the adhesion complexes. On loss of E-cadherin, cytoplasmic p120ctn might accumulate and contribute to tumor malignancy. We used suppression subtractive hybridization to search for genes regulated by E-cadherin expression. We isolated human Nanos1 as a transcript of which levels decrease on E-cadherin reexpression in a human breast cancer cell line. The hNanos1 protein bears a COOH-terminal (CCHC)(2) zinc finger domain and belongs to an evolutionarily conserved protein family sharing functions in germ cell development in both vertebrates and invertebrates. We found an inverse correlation between E-cadherin and hNanos1 expression in various cell lines and under diverse conditions. Conditional expression of hNanos1 in human colorectal DLD1 cancer cells functionally abolished cell-cell adhesion. It induced cytoplasmic translocation of p120ctn, as well as strong migratory and invasive properties. We also found that the NH(2)-terminal domain of hNanos1, which is conserved only among mammals, interacts with p120ctn. hNanos1 counteracted the stimulatory effect of p120ctn on cell protrusion formation. Together, these findings describe a new function for hNanos1 as a downstream effector of E-cadherin loss contributing to tumor progression. Targeting hNanos1 might be a promising strategy in the treatment of E-cadherin-negative tumors in particular.
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PMID:E-cadherin regulates human Nanos1, which interacts with p120ctn and induces tumor cell migration and invasion. 1704 63

p120 catenin is a cadherin-associated protein that regulates Rho GTPases and promotes the invasiveness of E-cadherin-deficient cancer cells. Multiple p120 isoforms are expressed in cells via alternative splicing, and all of them are essential for HGF signaling to Rac1. However, only full-length p120 (isoform 1) promotes invasiveness. This selective ability of p120 isoform 1 is mediated by reduced RhoA activity, both under basal conditions and following HGF treatment. All p120 isoforms can bind RhoA in vitro, via a central RhoA binding site. However, only the cooperative binding of RhoA to the central p120 domain and to the alternatively spliced p120 N terminus stabilizes RhoA binding and inhibits RhoA activity. Consistent with this, increased expression of p120 isoform 1, when compared with other p120 isoforms, is predictive of renal tumor micrometastasis and systemic progression, following nephrectomy. Furthermore, ectopic expression of the RhoA-binding, N-terminal domain of p120 is sufficient to block the ability of p120 isoform 1 to inhibit RhoA and to promote invasiveness. The data indicate that the increased expression of p120 isoform 1 during tumor progression contributes to the invasive phenotype of cadherin-deficient carcinomas and that the N-terminal domain of p120 is a valid therapeutic target.
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PMID:A p120 catenin isoform switch affects Rho activity, induces tumor cell invasion, and predicts metastatic disease. 1840 99

p120 catenin regulates the activity of the Rho family guanosine triphosphatases (including RhoA and Rac1) in an adhesion-dependent manner. Through this action, p120 promotes a sessile cellular phenotype when associated with epithelial cadherin (E-cadherin) or a motile phenotype when associated with mesenchymal cadherins. In this study, we show that p120 also exerts significant and diametrically opposing effects on tumor cell growth depending on E-cadherin expression. Endogenous p120 acts to stabilize E-cadherin complexes and to actively promote the tumor-suppressive function of E-cadherin, potently inhibiting Ras activation. Upon E-cadherin loss during tumor progression, the negative regulation of Ras is relieved; under these conditions, endogenous p120 promotes transformed cell growth both in vitro and in vivo by activating a Rac1-mitogen-activated protein kinase signaling pathway normally activated by the adhesion of cells to the extracellular matrix. These data indicate that both E-cadherin and p120 are important regulators of tumor cell growth and imply roles for both proteins in chemoresistance and targeted therapeutics.
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PMID:p120 catenin induces opposing effects on tumor cell growth depending on E-cadherin expression. 1901 20

Gonadotropin-releasing hormone (GnRH) receptor expression is often elevated in ovarian cancer, but its potential role in ovarian cancer metastasis has just begun to be revealed. Cadherin switching is a crucial step during tumorigenesis, particularly in metastasis. Here, we showed that GnRH is an inducer of E- to P-cadherin switching, which is reminiscent of that seen during ovarian tumor progression. Overexpression of P-cadherin significantly enhanced, whereas knockdown of P-cadherin reduced migration and invasion regardless of E-cadherin expression, suggesting that inappropriate expression of P-cadherin contributes to the invasive phenotype. These effects of P-cadherin were mediated by activation of the Rho GTPases, Rac1, and Cdc42, through accumulation of p120 catenin (p120(ctn)) in the cytoplasm. The use of p120(ctn) small interfering RNA or chimeric cadherin construct to inhibit p120(ctn) expression and cytoplasmic localization, respectively, resulted in significant inhibition of cell migration and invasion, with a concomitant reduction in Rac1 and Cdc42 activation, confirming that the effect was p120(ctn) specific. Similarly, the migratory/invasive phenotype could be reversed by expression of dominant-negative Rac1 and Cdc42. These results identify for the first time cadherin switching and p120(ctn) signaling as important targets of GnRH function and as novel mediators of invasiveness and tumor progression in ovarian cancer.
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PMID:Cadherin switching and activation of p120 catenin signaling are mediators of gonadotropin-releasing hormone to promote tumor cell migration and invasion in ovarian cancer. 2011 84


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