Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.10.1 (ERK)
95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The serine/threonine kinase Akt, a downstream effector of phosphatidylinositol 3-kinase (PI3K), is known to play an important role in antiapoptotic signaling and has been implicated in the aggressiveness of a number of different human cancers including acute myelogenous leukemia (AML). We have investigated the therapeutic potential of the novel Akt inhibitor, perifosine, on human AML cells. Perifosine is a synthetic alkylphospholipid, a new class of antitumor agents, which target plasma membrane and inhibit signal transduction networks. Perifosine was tested on THP-1 and MV 4-11 cell lines, as well as primary leukemia cells. Perifosine treatment induced cell death by apoptosis in AML cell lines. Perifosine caused Akt and ERK 1/2 dephosphorylation as well as caspase activation. In THP-1 cells, the proapoptotic effect of perifosine was partly dependent on the Fas/FasL system and c-jun-N-kinase activation. In MV 4-11 cells, perifosine downregulated phosphorylated Akt, but not phosphorylated FLT3. Moreover, perifosine reduced the clonogenic activity of AML, but not normal, CD34(+) cells, and markedly increased blast cell sensitivity to etoposide. Our findings indicate that perifosine, either alone or in combination with existing drugs, might be a promising therapeutic agent for the treatment of those AML cases characterized by upregulation of the PI3K-Akt survival pathway.
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PMID:Proapoptotic activity and chemosensitizing effect of the novel Akt inhibitor perifosine in acute myelogenous leukemia cells. 1792 81

Fluorescence in situ hybridization analysis was performed to evaluate P16 (9p21), P53 (17p13.1), RB1 (13q14), HER2 (17q11.2) genes and chromosomes 3, 7, 9 and 17 in 62 bladder cancer cystectomies. We found chromosome aneusomy ranged between 74.2% and 91.9%. The highest percentage of homozygous deletion was found in the P16 gene (48.4%), while the highest percentage of heterozygous deletion was in the RB1 gene (51.6%). Chromosome 17 aneusomy significantly increased in tumors with higher stage, and RB heterozygous deletion showed a higher percentage of tumors with positive lymph node. Multiple correspondence analysis (MCA) showed four different biological tumor profiles, but only one could be associated with survival, defining the most unfavorable biological profile, characterized by P53 and P16 as homozygous and heterozygous and RB as homozygous deletion. Overall survival was significantly shorter in patients with at least two positive variables out of the five detected by MCA using the Kaplan-Meier's method. The biological stratification of advanced bladder cancer patients is of particular clinical interest, because the assessment of genetic factors predictive of tumor aggressiveness may influence postoperative therapeutic strategies.
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PMID:Adverse genetic prognostic profiles define a poor outcome for cystectomy in bladder cancer. 1795 Feb 75

Basal-like breast carcinoma is an aggressive form of breast cancer, characterized by the absence of oestrogen receptor and HER2 expression, the presence of cytokeratin 5 and epidermal growth factor receptor expression, and by the up-regulation of stem cell regulatory genes. We show here that tumour tissues expressing high levels of SLUG mRNA show a basal-like breast carcinoma phenotype and that such tumours also express high levels of stem cell-regulatory genes, ie CD133, Bmi1. Further, we show that stem/progenitor cells, isolated from ductal breast carcinoma and from normal mammary gland as mammospheres, express SLUG, CD133, and Bmi1 mRNA and show a phenotype similar to that of basal-like breast carcinoma. We also report that SLUG expression in tumour tissues correlates with that of the hypoxia survival gene carbonic anhydrase IX. In this regard, we report that the exposure of SLUG-negative/luminal-like MCF-7 cells to a hypoxic environment promotes the onset of the basal-like breast carcinoma phenotype, together with up-regulation of the SLUG gene, which in turn blunts oestrogen receptor-alpha and boosts carbonic anhydrase IX gene expression. Finally, we show that SLUG expression promotes the invasiveness of MCF-7 cells exposed to hypoxia and sustains the in vivo aggressiveness of hypoxia-selected, MCF-7-derived cells in xenografts. These data indicate that SLUG gene expression is part of a hypoxia-induced genetic programme which sets up a basal/stem cell-like, aggressive phenotype in breast cancer cells.
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PMID:The basal-like breast carcinoma phenotype is regulated by SLUG gene expression. 1797 39

Activating mutations of the FMS-like tyrosine kinase-3 (FLT3) receptor occur in approximately 30% of acute myeloid leukemia (AML) patients and, at least for internal tandem duplication (ITD) mutations, are associated with poor prognosis. FLT3 mutations trigger downstream signaling pathways including RAS-MAP/AKT kinases and signal transducer and activator of transcription-5 (STAT5). We find that FLT3/ITD mutations start a cycle of genomic instability whereby increased reactive oxygen species (ROS) production leads to increased DNA double-strand breaks (DSBs) and repair errors that may explain aggressive AML in FLT3/ITD patients. Cell lines transfected with FLT3/ITD and FLT3/ITD-positive AML cell lines and primary cells demonstrate increased ROS. Increased ROS levels appear to be produced via STAT5 signaling and activation of RAC1, an essential component of ROS-producing NADPH oxidases. A direct association of RAC1-GTP binding to phosphorylated STAT5 (pSTAT5) provides a possible mechanism for ROS generation. A FLT3 inhibitor blocked increased ROS in FLT3/ITD cells resulting in decreased DSB and increased repair efficiency and fidelity. Our study suggests that the aggressiveness of the disease and poor prognosis of AML patients with FLT3/ITD mutations could be the result of increased genomic instability that is driven by higher endogenous ROS, increased DNA damage, and decreased end-joining fidelity.
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PMID:Internal tandem duplication of FLT3 (FLT3/ITD) induces increased ROS production, DNA damage, and misrepair: implications for poor prognosis in AML. 1819 5

Tumor cell migration, invasion, and angiogenesis are important determinants of tumor aggressiveness, and these traits have been associated with the motility stimulating protein autotaxin (ATX). This protein is a member of the ectonucleotide pyrophosphatase and phosphodiesterase family of enzymes, but unlike other members of this group, ATX possesses lysophospholipase D activity. This enzymatic activity hydrolyzes lysophosphatidylcholine to generate the potent tumor growth factor and motogen lysophosphatidic acid (LPA). In the current study, we show a link between ATX expression, LPA, and vascular endothelial growth factor (VEGF) signaling in ovarian cancer cell lines. Exogenous addition of VEGF-A to cultured cells induces ATX expression and secretion, resulting in increased extracellular LPA production. This elevated LPA, acting through LPA(4), modulates VEGF responsiveness by inducing VEGF receptor (VEGFR)-2 expression. Down-regulation of ATX secretion in SKOV3 cells using antisense morpholino oligomers significantly attenuates cell motility responses to VEGF, ATX, LPA, and lysophosphatidylcholine. These effects are accompanied by decreased LPA(4) and VEGFR2 expression as well as by increased release of soluble VEGFR1. Because LPA was previously shown to increase VEGF expression in ovarian cancer, our data suggest a positive feedback loop involving VEGF, ATX, and its product LPA that could affect tumor progression in ovarian cancer cells.
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PMID:Positive feedback between vascular endothelial growth factor-A and autotaxin in ovarian cancer cells. 1833 45

Neuroblastoma is a frequent pediatric tumor with a poor outcome in spite of aggressive treatment, even with autologous hematopoietic stem cell transplantation. The overall cure rate of 40% is unsatisfactory and new therapeutic strategies are urgently needed. AKT is a major mediator of survival signals that protect cells from apoptosis and regulate cell proliferation. The AKT signaling network is considered a key determinant of the biological aggressiveness of these tumors. In this article, the authors discuss the relation between activators of AKT in neuroblastoma, in particular, growth factors such as IGF-1, TRK, GDNF, VEGF and EGF, and their effects on tumoral proliferation, differentiation and apoptosis. Numerous other proteins interact with AKT in neuroblastoma. Several are relatively well characterized, such as PTEN and retinoic acid; others are new and potentially interesting, such as PKC and anaplastic lymphoma kinase. Specific inhibition of AKT has been studied, such as with LY249002, with significant effects on cell progression and apoptosis in tumoral cells. Moreover, a series of new drugs, such as geldanamycin and rapamycin, directly modify the expression of AKT in tumoral cells. Few specific inhibitors of AKT are available; less specific inhibitors are probably unsuitable therapeutic options in neuroblastoma. Drugs with a direct or indirect inhibitory effect on the AKT pathway, used alone or in combination with other drugs, seem to hold great promise as a new therapeutic modality in neuroblastoma.
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PMID:AKT pathway in neuroblastoma and its therapeutic implication. 1847 Oct 48

Extracellular acidification accompanies neoplastic transformation of tissues and increases with tumor aggressiveness [1, 2]. The intracellular signaling cascade triggered by this process remains poorly understood and may be linked to recently discovered proton-activated G protein-coupled receptors such as OGR1 and G2A [3, 4]. Here, we report that OGR1 and G2A are expressed in human medulloblastoma tissue and its corresponding neuronal cell line. We show that extracellular acidification activates phospholipase C, IP(3) formation, and subsequent Ca2+ release from thapsigargin-sensitive stores in neurons. The number of responsive cells and the amount of Ca2+ released from stores correlated positively with the extent of extracellular acidification. Ca2+ release recruited the MEK/ERK pathway, providing a mechanistic explanation for how acidification stimulates cell growth. In addition, acidification activated Ca2+-permeable ion channels through a mechanism dependent on phospholipase C but independent of store depletion or a cytoplasmic Ca2+ rise. Hence, extracellular acidification, to levels seen in tumor tissue, activates temporally and spatially distinct pathways that elevate Ca2+ and may be directly relevant for tumor cell biology.
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PMID:Extracellular acidification elicits spatially and temporally distinct Ca2+ signals. 1848 12

A diagnosis of gastrointestinal stromal tumor must be considered if a mesenchymal tumor is localized in the gastrointestinal tract, especially in the stomach. In daily practice diagnosis is based on the histology (cellular features and histologic architecture) and immunohistochemistry (cellular positivity with antibodies to CD117 and often to CD34). Expression of CD117 indicates the autoactivation of a type-III-receptor tyrosine kinase mediated by mutation of the KIT gene. This is lacking in the roughly 5% of cases which instead show a mutation of the PDGF receptor alpha gene. The estimation of dignity is difficult and can be uncertain in some cases. A malignancy grading according to the procedure in soft tissue tumors is not possible. Nowadays, however, the general consensus is that size of the tumor and number of mitoses are the most important criteria for appraising tumor aggressiveness and risk of metastasis. The tumor localization was later added to these criteria. Recent years have shown that mutation analysis can also provide information for judging tumor aggressiveness and predicting possible metastasis and response to therapy.
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PMID:[Gastrointestinal stromal tumors. Diagnosis and estimating aggressiveness]. 1849 60

S100 protein A8 and A9 naturally form a stable heterocomplex. Recently, we have proved that S100A9 overexpression in various adenocarcinomas is associated with poor tumor differentiation. In this study, we examined the relationship between the expression of each protein and the pathological parameters that reflect the aggressiveness of carcinoma, in invasive ductal carcinoma (IDC) of the breast. Serial paraffin-embedded tissue sections from 101 IDC cases were immunostained with respective monoclonal antibodies, and the results were as follows: 1) A positive correlation of immunoreactivity between S100A8 and S100A9 was noticed (r=0.873 and P<0.0001); 2) The percentage of S100A9-positive tumor cells was higher than that of S100A8-positive tumor cells (P<0.001), and S100A8 alone was not detected in any case; 3) Overlap between S100A8 and S100A9 staining patterns was found in the corresponding tissue areas, but S100A9 positivity was also observed in S100A8-negative tumor cells; 4) The immunopositivity for each protein also correlated with the mitotic activity, MIB-1 index, HER2 overexpression, node metastasis, and poor pT categories and pStage (P<0.05); 5) Co-expression of both proteins was associated with poor tumor differentiation, vessel invasion, node metastasis, and poor pStage (P<0.05). Furthermore, co-expression of the proteins was also observed in MCF-7 cells, and it was suggested that the immunolocalization is related with cell cycle. Our conclusions are as follows: 1) It is suggested that S100A8 is S100A9-dependently expressed and acquires the protein stability by S100A8/A9 heterocomplex formation; 2) S100A8 and S100A9 overexpression should be considered marker of poor prognosis in IDC.
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PMID:S100A8 and S100A9 overexpression is associated with poor pathological parameters in invasive ductal carcinoma of the breast. 1853 48

Cortactin, fascin-1 and EGFR are recognized as important factors in tumor progression. We tested the hypothesis that cortactin, fascin-1 and EGFR expression correlates with clinicopathological parameters of the four most common ovarian surface epithelial carcinomas--serous cystadenocarcinoma, mucinous cystadenocarcinoma, endometrioid adenocarcinoma, and clear cell carcinoma. Immunohistochemical analysis of cortactin, fascin-1 and EGFR was performed using tissue microarrays of 172 specimens comprising 69 serous cystadenocarcinomas, 44 mucinous cystadenocarcinomas, 45 endometrioid adenocarcinomas and 14 clear cell carcinomas. All ovarian carcinomas showed significant expression of cortactin, fascin-1 and EGFR in staining intensity, tumor percentages and immunostaining scores. In addition, higher immunostaining scores of fascin-1 correlated with more advanced cancer stages (TNM), poorer histological differentiation and poorer survival rate of mucinous cystadenocarcinoma. Similarly, higher immunostaining scores of cortactin correlated with T stages and histological differentiation of serous cystadenocarcinoma. The immunostaining scores of EGFR did not correlate with TNM stages, tumor differentiation or prognosis in the four ovarian surface epithelial carcinomas. Our findings suggest that cortactin and fascin-1 may serve as good biomarkers in evaluating aggressiveness of ovarian serous and mucinous cystadenocarcinoma. And the pharmacological inhibitors of fascin-1 activity may slow down tumor progression and prolong survival time in patients with mucinous cystadenocarcinoma.
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PMID:Association of cortactin, fascin-1 and epidermal growth factor receptor (EGFR) expression in ovarian carcinomas: correlation with clinicopathological parameters. 1877 88


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