Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0677930 (primary tumor)
 20,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Regional metastasis is an important prognostic factor for esophageal squamous cell carcinoma (ESCC). A reduced expression of cell adhesion molecules has been reported to be associated with tumor metastasis. However, the clinical significance of such adhesion molecules in metastatic lymph nodes remains unclear. The expression of adhesion molecules (E-cadherin, beta-catenin, CD44, CD44-v6 and Integrin beta 1) was studied in 71 primary tumors and their corresponding nodal metastases using immunohistochemical analyses. Regarding the clinicopathological features, a reduction in the expression of adhesion molecules in primary tumors was found to be significantly associated with the depth of invasion, lymph node metastasis, lymph and blood vessel permeations (p < 0.05). There was a significantly positive correlation between E-cadherin and beta-catenin (R = 0.55, p < 0.001), CD44 and CD44-v6 (R = 0.65, p < 0.001) in the primary tumor. In lymph node metastasis, there was significantly less staining for E-cadherin (p < 0.01), CD44 (p < 0.01), CD44-v6 (p < 0.05) and Integrin beta 1 (p < 0.01) in lymph node metastasis than in the primary tumor, and a significantly positive correlation between E-cadherin and beta-catenin (R = 0.55, p < 0.001). Regarding the number of lymph node metastases, a significant difference was found, and a reduced expression of E-cadherin, beta-catenin and CD44-v6 in the metastatic lymph nodes correlated with an increased number of lymph node metastases (p < 0.01). These findings are consistent with the idea that adhesion molecules have their own alterations, and a reduced expression of adhesion molecules in the metastatic lymph nodes correlated with an increased number of lymph node metastases.
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PMID:Relationship between the expression of adhesion molecules in primary esophageal squamous cell carcinoma and metastatic lymph nodes. 1466 31

Pilomatrix carcinoma is a rare skin tumor with an origin from hair matrix cells. The tumor is locally aggressive with a great tendency for recurrence, but the metastatic potential is limited. A pilomatrix carcinoma in 76-year-old female with lymph node metastases is presented. In addition to classical histopathological criteria and DNA ploidy analysis, a broad panel of antibodies was used for evaluation of the metastatic potential. Both primary tumor and lymph node metastasis revealed extremely high proliferation and apoptotic rates. High constant expressions of CD44v6 and P-cadherin were also observed. In the metastasis, significant reduction of E-cadherin and beta-catenin was detected. The best approach for assessment of metastatic potential of pilomatrix carcinoma seems to be the complex evaluation of routine histological criteria like vessel invasion, mitotic index, apoptotic count, and new molecular markers of cell death and adhesion.
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PMID:Pilomatrix carcinoma with lymph node metastases. 1500 91

Methylation of promoter regions of CpG-rich sites is an important mechanism for silencing of tumor suppressor genes (TSG). To evaluate the role of tumor suppressor genes caspase-8 (CASP8), TIMP-3, E-cadherin (CDH1), p16INK4A, and MGMT in medulloblastoma tumorigenesis, 51 medulloblastomas (46 primary tumor specimens, 5 cell lines) were screened for methylation of promoter linked CpG-islands. For CASP8, we examined the 5' UTR region that has been shown to be associated with expression of CASP8. As detected by methylation specific PCR, methylation rate was low for TIMP-3 (3% of tumor samples; 1/5 cell lines), for MGMT (0% of tumor samples; 1/5 cell lines), for p16INK4A (2% of tumor samples; 2/5 cell lines) and for CDH1 (8% of tumor samples; 1/4 cell lines). CASP8, however, was methylated in 90% of tumor samples and 4/5 cell lines examined. Screening other tumor entities for CASP8 methylation, we found a similarly high level in 6 neuroblastoma cell lines in contrast to 5 osteosarcoma-, 4 Ewing's sarcoma- and 6 non-embryonic tumor cell lines without any increased promoter methylation. From our results we conclude that methylation of the CASP8 5' UTR region may play a role in inactivation of CASP8 in neural crest tumors.
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PMID:Promoter methylation pattern of caspase-8, P16INK4A, MGMT, TIMP-3, and E-cadherin in medulloblastoma. 1502 56

Down-regulation of the E-cadherin-mediated cell adhesion system is strongly related to cancer invasion and metastasis. Aberrant CpG hypermethylation in the promoter region of the E-cadherin gene has been shown to be responsible for reduction of E-cadherin expression. The present study was designed to test the hypothesis that the demethylating agent 5-aza-2'-deoxycytidine (AZA) can restore the E-cadherin system and reduce the potential for metastasis. AZA treatment modified the methylation status of the 5' CpG island in the E-cadherin promoter, and induced re-expression of E-cadherin in human cancer cells whose E-cadherin expression had been silenced. The re-expressed E-cadherin was correlated with increased in vitro aggregation and reduced motility. After inoculation of cancer cells (MDA-MB-435S) into the mammary fat pads of mice with severe combined immunodeficiency, the mice were treated for nine consecutive weeks with AZA three times per week i.p. The AZA treatment suppressed both growth of the primary tumor and lung metastasis in comparison with untreated controls, suggesting that the suppression of metastasis may be, at least partly, attributable to restoration of E-cadherin expression. Therefore, inhibition of DNA methylation may be useful for preventing cancer metastasis.
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PMID:5-aza-2'-deoxycytidine restores the E-cadherin system in E-cadherin-silenced cancer cells and reduces cancer metastasis. 1506 2

Consorcial projects focused on 5 cancer types, breast-, colorectal-, head and neck- and pediatric cancers, and malignant melanoma. Breast cancer studies revealed unique splicing mechanisms concerning BRCA1. In sporadic breast cancers the involvement of DNA-repair genes was proved to be dependent on the histological type. Bone-metastatic tumors have been characterized by decreased NM23 and increased c-met and p53 expressions. C-erbB2 genotype of the primary tumor was not maintained frequently in bone metastases. Application of DNA-microarray and quantitative PCR technologies improved the prediction of therapeutic sensitivity of breast cancers. Colorectal cancer studies revealed regional inhomogenities (clusters) in various geographical regions of Hungary, which were distinct in the case of colonic and rectal cancers. To increase the sensitivity of fecal blood test of colorectal cancer screening, a new double-antibody test was developed and tested in a large cohort of patients. Genetic analysis revealed that hypermethylation is a significant factor in microsatellite instability which, and plays a role in silencing of APC and E-cadherin genes as well. The Hungarian pattern of TS polymorphism was also determined and was correlated not only with the efficacy of 5-FU treatment but with the progression of the disease as well. Population-based studies have been carried out in head and neck cancer patients (HNC) and smokers as well to reveal the genetic background of increasing tumor incidence. These studies revealed polymorphism in XRCC1/3 methylation enzyme gene which has preventive role. Other studies found frequent local immunosuppression in HNC patients. Studies indicated that the success of irradiation in this cancer type is dependent on the anti-vascular effects. Pediatric cancer studies determined the parameters of neuroblastoma screening based on VMA measurements. New splice variants of the WT1 gene involved in the monitoring of MRD of ALL patients was also described this year. We also obtained positive experimental data for the retinoic acid therapy of ALL. Melanoma studies extensively used DNA-microarray technology which identified 4 melanoma-specific and 2 melanoma progression-specific genes. In experimental human melanoma xenograft models we have identified 3 anti-metastatic agents: low molecular weight heparin, 2-methoxyestradiol and erythropoietin-alpha, where the later was characterized by specific effects on tumor vasculature.
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PMID:[Report of the National Oncology Research and Developement Consortium, 2003]. 1510

The loss of E-cadherin expression or function in epithelial carcinomas has long been thought as a primary reason for disruption of tight epithelial cell-cell contacts and release of invasive tumor cells from the primary tumor. Indeed, E-cadherin serves as a widely acting suppressor of invasion and growth of epithelial cancers, and its functional elimination represents a key step in the acquisition of the invasive phenotype for many tumors. Recent evidence indicates, however, that in addition to the loss of the "invasion-suppressor" E-cadherin, another adhesion molecule, N-cadherin, becomes upregulated in invasive tumor cell lines. N-cadherin was shown to be present in the most invasive and dedifferentiated breast cancer cell lines, and its exogenous expression in tumor cells induces a scattered morphology and heightened motility, invasion, and metastasis. N-cadherin cooperates with the FGF receptor, resulting in signals that lead to the up-modulation of MMP-9 and, hence, cellular invasion. In addition to a signaling function in metastasis, N-cadherin probably also supports the systemic dissemination of tumor cells by enabling circulating tumor cells to associate with the stroma and the endothelium at distant sites. Here, we summarize the various aspects of the E- to N-cadherin switching in epithelial carcinomas and its potential impact on metastatic progression.
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PMID:Cadherin switch in tumor progression. 1515 30

Previously, we demonstrated that loss of SEMA3F, a secreted semaphorin encoded in 3p21.3, is associated with higher stages in lung cancer and primary tumor cells studied with anti-vascular endothelial growth factor (VEGF) and SEMA3F antibodies. In vitro, SEMA3F inhibits cell spreading; this activity is opposed by VEGF. These results suggest that VEGF and SEMA3F compete for binding to their common neuropilin receptor. In the present report, we investigated the attractive/repulsive effects of SEMA3F on cell migration when cells were grown in a three-dimensional system and exposed to a SEMA3F gradient. In addition, we adapted the neurobiologic stripe assay to analyze the migration of tumor cells in response to SEMA3F. In the motile breast cancer cell line C100, which expresses both neuropilin-1 (NRP1) and neuropilin-2 (NRP2) receptors, SEMA3F had a repulsive effect, which was blocked by anti-NRP2 antibody. In less motile MCF7 cells, which express only NRP1, SEMA3F inhibited cell contacts with loss of membrane-associated E-cadherin and beta-catenin without motility induction. Cell spreading and proliferation were reduced. These results support the concept that in a first step during tumorigenesis, normal tissues expressing SEMA3F would try to prevent tumor cells from spreading and attaching to the stroma for further implantation.
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PMID:Semaphorin SEMA3F has a repulsing activity on breast cancer cells and inhibits E-cadherin-mediated cell adhesion. 1580 23

The case of a 46-year-old female with umbilical metastasis as a first sign of an ovarian carcinoma is reported with the results of immunohistochemical analysis of primary tumor and lymph node and umbilical metastases. All specimens were positive for cytokeratin 7, CA 125, E-cadherin, alpha-, beta-, and gamma-catenin, as well as for MSH2. Staining with cytokeratin 20 and MLH1 was negative, and Ki-67 labeled from 5% (in the center of the lesions) to over 25% (at the periphery of the lesions) of the nuclei. Beta-catenin showed membranous positivity in the central parts and absence of staining at the periphery of ovarian tumor and umbilical metastasis, whereas lymph node metastasis presented with uniform reaction throughout. The results of immunohistochemical staining could point to the mechanisms employed by malignant tumors during invasion and growth of metastasis and suggest the possible role of the microenvironment in the expression of some adhesion molecules on tumor cells.
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PMID:Umbilical metastasis (Sister Joseph's nodule) as a first sign of a disseminated ovarian carcinoma: comparative immunohistochemical analysis of primary tumor and its metastases. 1582 29

E-cadherin is a key cell adhesion molecule implicated as a tumor suppressor, which is frequently altered in hepatocellular carcinoma, especially in hepatitis B virus (HBV)-related tumors. Here, we report that HBV X protein (HBx) represses E-cadherin expression at the transcription level. Based on the differential effects of HBx natural variants, we determined that Lys-130 in the transactivation domain of HBx is critical for the E-cadherin repression. The repression effect of HBx was abolished after treatment with DNA methyltransferase inhibitor, 5'-Aza-2'dC. In addition, methylation-specific PCR analysis revealed that the CpG island 1 of E-cadherin promoter is hypermethylated by HBx. Furthermore, HBx induces DNA methyltransferase 1 expression by stimulating its transcription. Therefore, we conclude that HBx represses E-cadherin expression by inducing methylation-mediated promoter inactivation. The reduced E-cadherin expression results in dramatic morphological changes of the HBx-expressing cells. In addition, HBx-expressing cells aggregate poorly in suspension culture, reflecting their altered intercellular interactions. The biological significance was further demonstrated by the increased collagen invasion ability of HBx-expressing cells. Therefore, the present study suggests that HBx plays a role during hepatocellular carcinogenesis by favoring cell detachment from the surrounding cells and migration outside of the primary tumor site.
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PMID:Hepatitis B virus X protein represses E-cadherin expression via activation of DNA methyltransferase 1. 1600 61

Epithelial-mesenchymal transitions (EMTs) occur as key steps during embryonic morphogenesis, and are now implicated in the progression of primary tumors towards metastases. Recent advances have fostered a more detailed understanding of molecular mechanisms and networks governing EMT in tumor progression. Besides TGFbeta and RTK/Ras signaling, autocrine factors and Wnt-, Notch-, Hedgehog- and NF-kappaB-dependent pathways were found to contribute to EMT. Repression of E-cadherin by transcriptional regulators such as Snail or Twist emerges as one critical step driving EMT, and this stage is currently being molecularly linked with many of the new players. Increasing evidence suggests that EMT plays a specific role in the migration of cells from a primary tumor into the circulation and may provide a rationale for developing more effective cancer therapies.
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PMID:Molecular requirements for epithelial-mesenchymal transition during tumor progression. 1609 27


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