Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024623 (gastric cancer)
 36,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

G1 cyclins and cyclin-dependent kinase (CDK) complexes play important roles in G1 cell cycle transition, and their overexpression is implicated for neoplasia. The p27 protein (p27) negatively regulates G1 progression by binding to G1 cyclins/CDK complexes and inhibits their activity, resulting in inhibition of entry to the cell cycle. We investigated overexpression of cyclin D1 (CCND1), cyclin D2 (CCND2), cyclin E (CCNE), CDK2, and CDK4, in addition to p27, in 260 gastric cancer cases on the basis of Western blots, reverse transcriptase-polymerase chain reaction Southern blots, and immunohistochemistry to clarify the roles of these proteins in tumor progression and prognosis. Examination of 20 cases of fresh cancer and matched normal tissues demonstrated a clear tendency for increased mRNA synthesis to be more frequent than expected from protein levels, and a direct correlation between p27 protein and mRNA was not found. Immunohistochemistry demonstrated 21. 5%, 34.2%, 30.4%, 44.2%, and 48.0% positivity for CCND1, CCND2, CCNE, CDK2, and CDK4, respectively, in the 260 gastric cancer cases. Overexpression of CCND2 and CDK4 significantly correlated with tumor progression. Moreover, CCND2 cytoplasmic staining (26.2%) appeared to be strictly linked with progression, whereas nuclear staining (7. 8%) demonstrated an inverse correlation. Survival curves showed CCND2 (especially cytoplasmic staining) and CDK4 positivity to be associated with a poor prognosis and CCNE positivity with a better prognosis. Tumors with high p27 labeling indices (LIs) were well differentiated, with low levels of invasion and lymph node metastasis. p27-negative cases (37.3%) demonstrated a poor prognosis. Multivariate analysis revealed positivity for CCND2 and negativity for p27 to be independent prognostic factors. There were no direct links among CCND2, CCNE, CDK4, and p27. The results indicate that CCND2 cytoplasmic localization might reflect an important physiological role in tumor progression, whereas CCNE overexpression correlates with differentiation and a good prognosis, possibly because of accumulation of inactive forms of CCNE-CDK2 complexes. Loss of p27 caused by degradation activity may affect tumor cell growth in the presence of an altered extracellular matrix, facilitating metastasis. Cell-cycle-regulatory proteins appear to work independently.
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PMID:Cyclin D2 overexpression and lack of p27 correlate positively and cyclin E inversely with a poor prognosis in gastric cancer cases. 1066 88

An accumulation of multiple genetic and epigenetic alterations of oncogenes, tumor suppressor genes, DNA repair genes, cell cycle regulators, cell adhesion molecules, and the growth factor/receptor system is involved in the course of multistep conversion of normal epithelial cells to clinical gastric cancer. Some of them differ depending on the histological type, well-differentiated (intestinal) and poorly differentiated (diffuse) types, suggesting the presence of two distinct genetic pathways. Genetic instability, chromosomal instability (telomere reduction), and immortality (activation of telomerase and expression of telomerase reverse transcriptase: TERT) participate in the initial step of stomach carcinogenesis. Because TERT protein expression precedes the telomerase activities in precancerous lesions, TERT expression may be a prerequisite for telomerase activation. The cyclin E gene is amplified in 15%-20% of gastric cancer. Reduced expression of a cyclin-dependent kinase (CDK) inhibitor, p27Kip1, is frequently found in gastric cancer associated with high grade malignancy. E2F-1, an important downstream target of cyclins/CDKs, is overexpressed in about 40% of gastric carcinomas, whereas gene amplification of E2F-1 rarely occurs. Loss of heterozygosity (LOH) of p73, the p53-related new tumor suppressor gene, preferentially occurs in well-differentiated adenocarcinomas of foveolar type expressing pS2, a gastric-specific trefoil factor, indicating the importance of p73 LOH in the genesis.
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PMID:Genetic and epigenetic alterations in multistep carcinogenesis of the stomach. 1077 29

In the present study, the expression and prognostic role of p27 were immunohistochemically investigated in 413 curatively resected gastric carcinomas. Strong p27 expression in more than 50% of the tumour cells could be detected in 57.4% (n = 237) whereas 42.6% of the tumours (n = 176) only showed p27 expression in less than 50% of the tumour cells. No significant correlation could be observed between p27 expression and the prognostic parameters pT category, pN category, blood and lymphatic vessel invasion as well as with tumour histology. Concerning other cell cycle associated proteins, p27 expression was inversely correlated with p21 expression, however, there was no correlation either with cyclin D1 and cyclin E or with expression of p53, bcl-2 and tumour cell proliferation. Univariate survival analysis revealed a poorer prognostic outcome for patients with tumours expressing p27 in more than 50% of the tumour cells (p < 0.049). However, by multivariate analysis, this prognostic influence of p27 could not be verified as independent from the known prognostic parameters of the pTNM-system (p < 0.325). The present data on 413 curatively resected gastric carcinomas suggest, that expression of p27, analyzed alone or in combination with multiple cell cycle regulatory proteins, has no prognostic value in gastric cancer.
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PMID:Prognostic value of the cyclin-dependent kinase inhibitor p27Kip1 in gastric cancer. 1092 8

Cyclin D1 and E have been found to be deregulated and overexpressed in various types of cancers. In order to study the cell cycle regulatory mechanisms in gastric cancer, we have analyzed the protein expression of cyclin D1 and cyclin E in 76 tumor specimens from patients with primary gastric cancer, using immunohistochemistry. Overexpression of cyclin D1 was observed in 38 cases (50.0%). Overexpression of cyclin E was observed in 40 cases (52.6%). There was no significant difference between the expression of cyclin D1 and any clinicopathological factor. Cyclin E overexpression was correlated with a high incidence of lymph node metastasis, a low incidence of T1, and with Stage I. There was no significant difference in survival curves between cyclin D1 (+) and cyclin D1 (-). The survival curves of cyclin E (-) were significantly higher than those of cyclin E (+). These results suggested that in gastric carcinoma, cyclin E overexpression was useful as a prognostic indicator, but cyclin D1 was not.
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PMID:Immunohistochemical study on the expression of cyclin D1 and E in gastric cancer. 1105 20

Molecular characterization of eight gastric cancer cell lines established in Japan are summarized according to the genetic and epigenetic alterations and growth factor status. TMK-1 poorly differentiated adenocarcinoma cell line harbors mutant p53 tumor suppressor gene and rearrangement of p15MTS2. MKN-1 adenosquamous carcinoma line with mutant p53 reveals silencing of E-cadherin by promoter CpG hypermethylation. MKN-7 well-differentiated adenocarcinoma cell line has amplification of c-erbB2 oncogene and cyclin E gene. MKN-28 well-differentiated adenocarcinoma cell line reveals mutations in p53 and APC tumor suppressor genes and silencing of CD44. The MKN-45 poorly differentiated adenocarcinoma cell line with wild-type p53 is characterized by homozygous deletion of p16CDKN2/MTS1/INK4A and p15MTS2, amplification of c-met oncogene and promoter mutation of E-cadherin. MKN-74 derived from moderately differentiated tubular adenocarcinoma has wild-type p53. KATO-III signet ring cell carcinoma line has genomic deletion of p53, amplification of K-sam and c-met oncogene and mutation of E-cadherin. HSC-39 signet ring cell carcinoma cell line harboring p53 missense mutation has homozygous deletion of p16CDKN2/MTS1/INK4A and p15MTS2, amplifications of c-myc, c-met, K-sam and CD44 gene and mutation in beta-catenin gene.
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PMID:Molecular characteristics of eight gastric cancer cell lines established in Japan. 1110 48

Genetic and epigenetic alterations of multiple cancer-related genes and molecules are implicated in the development and progression of human gastric carcinomas. Reactivation of telomerase, inactivation of p53 tumor suppressor gene, overexpression of cyclin E, and reduced expression of p27 KIP1 by disorganized degradation in proteasome are common events of both well-differentiated and poorly differentiated gastric adenocarcinomas. Inactivation of hMLH1 mismatch repair gene by CpG hypermethylation resulting in microsatellite instability, amplification of c-erbB2 oncogene, inactivation of APC tumor suppressor gene, and K-ras mutations are preferentially associated with well-differentiated gastric cancer. Conversely, reduction or loss of E-cadherin and catenins by both mutation and CpG hypermethylation and K-sam and c-met oncogene amplification are necessary for the development and progression of poorly differentiated or scirrhous gastric carcinomas. Interaction between cancer cells expressing c-met and hepatocyte growth factor from stromal cells is implicated in morphogenesis of gastric cancer.
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PMID:Genetic and epigenetic changes in stomach cancer. 1124 97

Two types of gastric adenocarcinoma can be distinguished histopathologically: the diffuse and the intestinal type. Molecular pathology supports this theory by showing differences in the genetic pathways of both tumor types. In addition to known pathomorphological factors of prognosis, e.g., depth of tumor infiltration, number of lymph node metastases and resection margins, a few genes have been suggested to have prognostic impact in gastric carcinoma. Clinically relevant molecules whose expression or structure is altered include the plasminogen activator (uPA) and its inhibitor PAI-1 (plasminogen activator inhibitor type 1), the cell cycle regulator cyclin E, epidermal growth factor (EGF), the apoptosis inhibitor bcl-2, the cell adhesion molecule E-cadherin, and the multifunctional protein beta-catenin. Gene amplification and protein overexpression of the growth factor receptors c-erbB-2 and K-sam may be prognostic factors for intestinal-type and diffuse-type gastric cancer, respectively. In addition, genetic instability is commonly seen. There has long been evidence for a genetic predisposition to gastric cancer by epidemiological studies and case reports. Very recently, germ line mutations of E-cadherin have been identified that are responsible for a dominantly inherited form of diffuse-type gastric cancer and could be used to identify individuals that are at high risk.
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PMID:Gastric adenocarcinoma: pathomorphology and molecular pathology. 1131 54

We have investigated methods to predict lymph node metastasis in early gastric cancer. First, the efficacy of fluorescence in situ hybridization (FISH) using the dual-color method was evaluated as a potential marker of lymph node metastasis in 20 early gastric cancers. A significant increase in the fraction of cells with a decrease in p53 was observed in early gastric cancer compared with normal tissues. More importantly, a significant increase in the fraction of cells with p53 deletion was observed in patients with lymph node metastasis. The predictive accuracy was 45%. Second, the relationship between the degree of expression of biological markers and lymph node metastasis was examined. High expression of p27 and cyclin E had a strong correlation with lymph node metastasis. Moreover, all patients with combined high expression of p27, cyclin E, and matrix metalloproteinase-9 had lymph node metastasis. However, these represented only 21% of cases with lymph node metastasis. Difficulty in the clinical use of these biological markers to detect lymph node metastasis depends on the feedback mechanism of cell cycle regulators or heterogeneity of the lesion. These problems should be resolved in the near feature.
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PMID:[Treatment of lymph node metastasis from the viewpoint of surgical oncology]. 1143 7

The investigation of molecular and genetic changes in gastric cancer has brought new insights into the pathogenesis of the disease. Knowledge of the genetic abnormalities and altered molecules could be used for differential diagnosis in case of an unknown primary tumor, allows their evaluation as prognostic factors, and could open novel avenues for more specific clinical interventions. Clinically relevant molecules whose expression or structure is altered include the plasminogen activator and its inhibitor plasminogen activator inhibitor type 1, the cell cycle regulator cyclin E, epidermal growth factor, the apoptosis inhibitor bcl-2, the cell adhesion molecule E-cadherin, and the multifunctional protein beta-Catenin. In addition, genetic instability is commonly seen. Gene amplification and protein overexpression of the growth factor receptors c-erbB2 and K-sam may be prognostic factors for intestinal- and diffuse-type gastric cancer, respectively. There has long been evidence for a genetic predisposition to gastric cancer by epidemiological studies and case reports. Very recently, germ line mutations of E-cadherin have been identified that are responsible for a dominantly inherited from of diffuse-type gastric cancer and could be used to identify individuals that are at high risk. The clinical implications of the recent findings for diagnosis, prognosis, therapy, and risk assessment are discussed.
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PMID:The use of molecular biology in diagnosis and prognosis of gastric cancer. 1152 6

BACKGROUND: To elucidate the role that cyclin E overexpression plays in the progression of early gastric cancer, we examined the expression of cyclin E and p53, as abnormal p53 expression is linked with cyclin E overexpression in exerting adverse affects on the cell cycle.METHODS: Specimens from 108 early gastric cancers were stained by an immunohistochemical method, using anti-cyclin E and anti- p53 antibodies.RESULTS: The positivity rate of cyclin E expression in early gastric cancer was 33% (36/108). Cyclin E-positive tumors invaded more deeply ( P < 0.05), infiltrated lymphatic vessels more frequently ( P < 0.01), showed a higher incidence of differentiated cancer ( P < 0.01), and more often expressed p53 ( P < 0.01) than cyclin E-negative tumors. Differentiated cancers showing coexpression of cyclin E and p53 were more likely to metastasize to the lymph nodes.CONCLUSIONS: Overexpression of cyclin E may promote the progression of early gastric cancer.
Gastric Cancer 1998 Mar 01
PMID:Role of cyclin E and p53 expression in progression of early gastric cancer. 1195 61


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