UMLS:C0178874 - FACTA Search

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

Gastric cancer develops through the accumulation of multiple genetic lesions that involve oncogenes, tumor suppressor genes and DNA mismatch repair genes. Lauren's classification of gastric carcinoma does not correlate with cellular phenotypes expressed by neoplastic cells and gastric and intestinal cell differentiation markers are widely expressed in both types (intestinal and diffuse) of gastric carcinoma. In contrast, the study of the correlation between morphologic events and genetic alterations, which come about in the cancerogenetic process, seems to indicate the existence of distinct cancerogenetic pathways for the intestinal (or glandular) and diffuse type carcinoma, both originating from a HP-positive gastritis. In particular there seem to be three different profiles of cancerogenesis: 1) p53 mutations which accompany the onset of dysplasia and intestinal-type carcinoma; 2) DNA repair mechanism alterations conditioning microsatellite instability, seem mutually exclusive with regards to p53 mutations. Microsatellite instability correlates with antrally located intestinal-type carcinoma, with little metastatic tendency and a better prognosis; microsatellite instability frequently involves the TGF beta RII, IGF II R genes or the BAX proapoptotic gene, in as much as these contain microsatellite sequences; 3) alterations of E-cadherin, both with regards to mutations and abnormal expression. These lead to junctional and cell polarity loss and are primarily associated with diffuse type carcinoma, which is characterized by poorly cohesive neoplastic cells. Some tumors, initially arising as intestinal-type (glandular structure), acquire a mixed histotype during neoplastic progression, in which both the typical alterations of the intestinal cancerogenesis (p53, microsatellite instability) and those of the diffuse carcinoma (E-cadherin) coexist. The identification of a mixed histotype could have importance both in epidemiologic, pathogenetic and prognostic terms.
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PMID:Molecular mechanisms involved in the pathogenesis of gastric carcinoma: interactions between genetic alterations, cellular phenotype and cancer histotype. 1181 65

The homeodomain-containing transcription factor NKX3.1 is a putative prostate tumor suppressor that is expressed in a largely prostate-specific and androgen-regulated manner. Loss of NKX3.1 protein expression is common in human prostate carcinomas and prostatic intraepithelial neoplasia (PIN) lesions and correlates with tumor progression. Disruption of the murine Nkx3.1 gene results in defects in prostate branching morphogenesis, secretions, and growth. To more closely mimic the pattern of NKX3.1 loss that occurs in human prostate tumors, we have used Cre- and loxP-mediated recombination to delete the Nkx3.1 gene in the prostates of adult transgenic mice. Conditional deletion of one or both alleles of Nkx3.1 leads to the development of preinvasive lesions that resemble PIN. The pattern of expression of several biomarkers (Ki-67, E-cadherin, and high-molecular-weight cytokeratins) in these PIN lesions resembled that observed in human cases of PIN. Furthermore, PIN foci in mice with conditional deletion of a single Nkx3.1 allele lose expression of the wild-type allele. Our results support the role of NKX3.1 as a prostate tumor suppressor and indicate a role for this gene in tumor initiation.
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PMID:Conditional loss of Nkx3.1 in adult mice induces prostatic intraepithelial neoplasia. 1183 15

Invasion and dissemination of well-differentiated carcinomas are often associated with loss of epithelial differentiation and gain of mesenchymal-like capabilities of dedifferentiated tumor cells at the invasive front. However when analysing central areas of metastases of colorectal carcinomas one finds a regain of the differentiated epithelial growth patterns like in the primary tumor. More than 80% of these tumor have loss of function mutations in the APC tumor suppressor gene, leading to an overexpression of beta-catenine. In its nuclear pool beta-catenine acts as a transcription factor and is now considered as one of the main oncogenic proteins in colorectal carcinogenesis. We could define several molecules important for the processes of invasion and dissemination, like MMP-7, uPA, laminin-5, as target genes activated by nuclear beta-catenine. Moreover the characteristic phenotypic changes during tumor progression were associated with distinct expression patterns of beta-catenine and E-cadherin. Nuclear beta-catenine was found in dedifferentiated mesenchyme-like tumor cells at the invasive front, but strikingly, like in central areas of the primary tumors, was localized to the membrane and cytoplasm in polarized epithelial tumor cells in the metastases. This was accompanied by changes in the proliferative activity. Based on these data, we postulate that an important driving force for progression of well-differentiated colorectal carcinomas is the specific environment, initiating two transient phenotypic transition processes by modulating intracellular beta-catenine distribution in the tumor cells.
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PMID:[The Rudolf Virchow Prize 2001. The role of the oncoprotein beta-catenin ni the progression of colorectal cancers]. 1189 5

Cadherins function to promote adhesion between adjacent cells and play critical roles in such cellular processes as development, tissue maintenance, and tumor suppression. We previously demonstrated that heterotrimeric G proteins of the G12 subfamily comprised of Galpha12 and Galpha13 interact with the cytoplasmic domain of cadherins and cause the release of the transcriptional activator beta-catenin (Meigs, T. E., Fields, T. A., McKee, D. D., and Casey, P. J. (2001) Proc. Natl. Acad. Sci. U. S. A. 98, 519-524). Because of the importance of beta-catenin in cadherin-mediated cell-cell adhesion, we examined whether G12 subfamily proteins could also regulate cadherin function. The introduction of mutationally activated G12 proteins into K562 cells expressing E-cadherin blocked cadherin-mediated cell adhesion in steady-state assays. Also, in breast cancer cells, the introduction of activated G12 proteins blocked E-cadherin function in a fast aggregation assay. Aggregation mediated by a mutant cadherin that lacks G12 binding ability was not affected by activated G12 proteins, indicating a requirement for direct G12-cadherin interaction. Furthermore, in wound-filling assays in which ectopic expression of E-cadherin inhibits cell migration, the expression of activated G12 proteins reversed the inhibition via a mechanism that was independent of G12-mediated Rho activation. These results validate the G12-cadherin interaction as a potentially important event in cell biology and suggest novel roles for G12 proteins in the regulation of cadherin-mediated developmental events and in the loss of cadherin function that is characteristic of metastatic tumor progression.
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PMID:Galpha12 and Galpha13 negatively regulate the adhesive functions of cadherin. 1197 33

BACKGROUND: Beta-catenin plays two distinct roles, in intercellular adhesion by E-cadherin, and in transcriptional activation via TCF/LEF. Theoretically, the former role is tumor-suppressive, while the latter is oncogenic. We investigated the involvement of beta-catenin in the histogenesis and clinical outcome of gastric cancers.METHODS: The expression pattern of beta-catenin was evaluated in stomach and lymph nodes from 82 patients with gastric cancer by immunohistochemistry and Western blot. Its association with E-cadherin expression and clinicopathological factors, including histological type and postoperative survival, was examined.RESULTS: Beta-catenin expression was classified into two patterns, normal (23.2%; 19 patients) and disordered (76.8%; 63 patients), the latter being subclassified as overexpressed (7.3%; 6 patients) and reduced (69.5%; 57 patients). A disordered beta-catenin expression pattern was significantly correlated with diffuse type adenocarcinoma and deep tumor infiltration ( P = 0.0154), but was not associated with lymph node metastasis ( P = 0.7877). E-cadherin was always expressed at the cell membrane, and disordered beta-catenin expression was significantly associated with reduced E-cadherin expression ( P < 0.0001). On univariate analysis, the beta-catenin pattern, as well as depth of invasion and lymph node metastasis, was associated with postoperative prognosis; however, only lymph node metastasis was an independent prognostic factor on multivariate analysis. Interestingly, different disordered patterns of beta-catenin expression, both overexpressed and reduced, were associated with E-cadherin reduction and poorer postoperative survival.CONCLUSION: Although disordered patterns of beta-catenin expression varied in gastric cancers, they were consistently associated with cancer progression.
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PMID:Clinical significance of disordered beta-catenin expression pattern in human gastric cancers. 1198 36

Carcinoma of the ovary is the leading cause of death from gynecological cancer in western countries. Ovarian carcinoma is commonly associated with the accumulation of fluid containing malignant cells in the peritoneal, and not infrequently in the pleural cavity. The differentiation of these cells from reactive mesothelial cells is at times difficult. In addition, tumor progression in ovarian carcinoma and the biological characteristics of carcinoma cells in effusions compared to their counterparts in solid tumors are poorly understood. This review details the current knowledge regarding diagnostic and biologic aspects of effusion cytology, with emphasis on ovarian carcinoma. Results from our first studies of effusions are subsequently presented. These attempt to address several issues. First, to improve the diagnostic ability to detect cancer cells in effusions using antibodies designed for the differentiation of epithelial cells from mesothelial cells. Secondly, to study genotypic and phenotypic differences between ovarian carcinoma cells in effusions, solid primary tumors and metastatic lesions, as well as to compare malignant cells in peritoneal and pleural effusions. These studies of carbohydrate antigens, E-cadherin complex and matrix metalloproteinases (MMP) attempted to evaluate whether ovarian carcinoma cells in effusions possess true metastatic properties, or are similar to the cells in primary tumors, thereby merely representing the result of a shedding process. Finally, the prognostic role of these molecules was studied in solid tumors from a patient cohort consisting of long- and short-term survivors, followed for up to 20 years. Figure 1 on http://www.esacp.org/acp/2001/23-3,4/davidson.htm.
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PMID:Ovarian carcinoma and serous effusions. Changing views regarding tumor progression and review of current literature. 1208 92

Associated with the metastatic progression of epithelial tumors is the dynamic regulation of cadherins. Whereas E-cadherin is expressed in most epithelium and carcinomas, recent studies suggest that the up-regulation of other cadherin subtypes in carcinomas, such as N-cadherin, may function in cancer progression. We demonstrate that a signal transduction cascade links the N-cadherin.catenin adhesion complex to up-regulation of the anti-apoptotic protein Bcl-2. In suspension, aggregates of DU-145 cells, an E-cadherin expressing human prostate carcinoma line, survive loss of integrin-dependent adhesion by a different anti-apoptotic signaling pathway than the N-cadherin expressing lines PC3 and PC3N. N-cadherin intercellular adhesion mediates a 3.5-fold increase in Bcl-2 protein expression, whereas the level of the proapoptotic protein Bax remains constant. Only N-cadherin ligation in PC3 cells, which express both N-cadherin and E-cadherin, is sufficient to induce activation of Akt/protein kinase B. N-cadherin homophilic ligation initiates phosphatidylinositol 3-kinase-dependent activation of Akt resulting in Akt phosphorylation of Bad on serine 136. Following N-cadherin homophilic adhesion phosphatidylinositol 3-kinase was identified in immunoprecipitates of the N-cadherin.catenin complex. The recruitment of phosphatidylinositol 3-kinase to the adhesion complex is dependent on ligation of N-cadherin and an organized actin cytoskeleton because cytochalasin D blocks the recruitment. We propose that N-cadherin homophilic adhesion can initiate anti-apoptotic signaling, which enhances the Akt cell survival pathway in metastatic cancer.
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PMID:Signal transduction from N-cadherin increases Bcl-2. Regulation of the phosphatidylinositol 3-kinase/Akt pathway by homophilic adhesion and actin cytoskeletal organization. 1209 80

The native three-dimensional architecture of carcinomas, which governs numerous autocrine-paracrine interactions related to tumor progression, cannot be faithfully recreated in most in vitro models. Even when the three-dimensional architecture is recreated in artificial scaffolds such as soft agar, this approach does not truly recreate the natural microenvironment of the tumor. Multicellular spheroids can reasonably recreate in vitro the natural three-dimensional architecture of carcinomas, but even the most efficient gene delivery vectors will penetrate only the outer layers of these structures and hence only a small fraction of cells will receive the gene of interest. If the multicellular spheroids are disrupted into a single-cell suspension in order to achieve high transfection efficiency, the single-cell production may have so altered the gene expression profile of the spheroid as to bring into question its present relevancy to in vivo tumor progression. Our laboratory has developed a human-SCID (severe combined immunodeficient) mouse model of inflammatory breast cancer, MARY-X, which grows as tight multicellular spheroids in vitro and as lymphovascular emboli in vivo. The spheroids, which express only low levels of surface sialyl-Lewis(x/a) (sLe(x/a)), are able to form compact homotypic cell clumps mediated by an intact, overexpressed E-cadherin/alpha,beta-catenin axis. The spheroids can be fully disrupted by trypsin proteolysis, anti-E-cadherin antibodies, or Ca(2+) depletion. Of these approaches the disruption with depleted Ca(2+), complete after 30 min, is fully reversible by the readdition of Ca(2+) within 6 hr. This time interval allows for a transfection "window" in which successful gene delivery can be achieved before spheroid reformation. Retroviruses (10(6)-10(7) CFU/ml) carrying the gene encoding either green fluorescent protein (GFP), a dominant-negative E-cadherin mutant (H-2K(d)-E-cad), its control (H-2K(d)-E-cad Delta C25), or alpha-1,3-fucosyltransferase III (FucT-III), an enzyme that increases surface sLe(x/a), were used to transfect either intact (wild-type) or disadhered/readhered (reformed) spheroids. There were marked differences in transfection efficiency in the reformed versus wild-type spheroids. Retroviral transfection of GFP resulted in successful delivery of this reporter gene to only the outer layer of cells of the wild-type spheroids, but to all layers of the reformed spheroids. A single retroviral transfection of H-2K(d)-E-cad, H-2K(d)-E-cad Delta C25, or FucT-III produced evidence of their respective gene expression at 72 hr throughout all layers of the reformed spheroids, but only H-2K(d)-E-cad and FucT-III produced progressive disadherence. Both H-2K(d)-E-cad-MARY-X and FucT-III-MARY-X lost their ability to form lymphovascular emboli in SCID mice. This reversible model of spheroid formation has provided us with insight into the pathogenesis of inflammatory breast carcinoma. If more broadly applied, this model could be used to examine the effects of any gene, using any gene delivery system in the three-dimensional context of native tumoral architecture.
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PMID:Reversible model of spheroid formation allows for high efficiency of gene delivery ex vivo and accurate gene assessment in vivo. 1213 77

Snail genes encode zinc finger transcription factors required for the development of vertebrate and invertebrate embryos. They trigger epithelial to mesenchymal transitions (EMTs), thereby allowing epithelial cells to emigrate from their place of origin and form tissues such as the mesoderm and the neural crest. Snail genes are also involved in the EMTs responsible for the acquisition of invasiveness during tumor progression. This aspect of their activity is associated with their ability to directly repress E-cadherin transcription. Here we describe the existence of an active human Snail retrogene, inserted within an intron of a novel evolutionarily conserved gene and expressed in different human tissues and cell lines. Functional analyses in cell culture show that this retrogene maintains the potential to induce EMTs, conferring migratory and invasive properties to epithelial cells. In light of this data, we have renamed it SNAIL-like, a new player that must be considered in both physiological and pathological studies of SNAIL function in humans.
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PMID:Biological potential of a functional human SNAIL retrogene. 1215 3

This study was designed to characterize the expression profiles of nine bladder cancer cell lines (T24, J82, 5637, HT1376, RT4, SCaBER, TCCSUP, UMUC-3, and HT1197) using cDNA microarrays (8976 genes and expressed sequence tags). Novel targets involved in bladder cancer progression of potential clinical relevance were validated by immunohistochemistry using tissue microarrays of primary bladder tumors (n = 193 cases). Hierarchical clustering classified uroepithelial cells based on their histopathogenesis and cell cycle alterations. Keratin 10 and caveolin-1 transcripts were more abundant in tumor cells from squamous and invasive origin. Their combined expression was shown to stratify bladder tumors and define squamous differentiation. To assess the robustness of the clustering analysis, a bootstrap resampling technique was used. This grouped tumor cell lines based on their biological properties, including cell cycle and cell adhesion features. E-cadherin, zyxin, and moesin were identified as genes differentially expressed in these clusters and related to the p53, RB, and INK4A status of the cell lines. Loss of these adhesion molecules was associated with stage and grade in primary tumors (P < 0.05), and moesin expression was also associated with survival (P = 0.01). Deregulation of cell cycle and apoptotic pathways, such as mutations or altered expression of p53, pRB, and INK4A (p16), is necessary for uroepithelial transformation. However, it appears that deregulation of cell adhesion is a common event associated with tumor progression in uroepithelial neoplasms.
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PMID:Molecular profiling of bladder cancer using cDNA microarrays: defining histogenesis and biological phenotypes. 1600 74

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