Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dysregulation of hepatocyte growth factor (HGF)-induced signaling via its receptor tyrosine kinase Met results in tumor progression and metastasis. To initiate signaling, pro-HGF must be proteolytically activated to reveal a secondary Met binding site within the serine protease-like beta-chain of HGF. Although HGF/Met is a large complex, we sought to discover relatively small antagonists that might interfere with this critical Met binding region. Pools of disulfide-constrained random peptide libraries displayed on phage were selected for binding to HGF, ultimately resulting in a disulfide-constrained 15-mer peptide (VNWVCFRDVGCDWVL) termed HB10, which bound to the recombinant human HGF beta-chain (HGF beta) and competitively inhibited binding to Met with an IC(50) of 450 nM. In MDA-MB435 cells, HB10 reduced HGF-dependent Met phosphorylation by 70%, and phosphorylation of downstream kinases AKT and ERK1/ERK2 by 74% and 69%, respectively. Addition of HB10 also inhibited HGF-dependent migration of these cells with an IC(50) of approximately 20 microM. The 2D (1)H-NMR structure of HB10 revealed a beta-hairpin loop stabilized by the disulfide bond and cross-strand pairing of Trp3 and Trp13. HGF beta mutants deficient in Met binding also have reduced HB10 binding, suggesting an overlapping binding site. Notably HB10 did not inhibit full length HGF binding to Met. Thus steric hindrance of the interaction between HGF beta domain binding to Met is sufficient for inhibiting full-length HGF-dependent Met signaling and cell migration that is consistent with a noncompetitive inhibitory mechanism of Met signal transduction.
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PMID:Noncompetitive inhibition of hepatocyte growth factor-dependent Met signaling by a phage-derived peptide. 1897 60

The role of transforming growth factor beta (TGFbeta) in tumor promotion and in angiogenesis is context-dependent. While TGFbeta prevents tumor growth and angiogenesis in early phases of tumor development, evidence is accumulating about its pro-angiogenic and tumor promotion activities in late-stages of tumor progression. Here we have studied, in an experimental context previously reported to disclose the pro-angiogenic effects of TGFbeta, the blocking activity of TGFbeta antagonist peptides. In agreement with previous results, we have observed that TGFbeta exerts a powerful pro-angiogenic activity on human normal dermal microvascular endothelial cells (MVEC), by promoting invasion and capillary morphogenesis in Matrigel. No apoptotic activity of TGFbeta was observed. By RT-PCR we have shown that TGFbeta up-regulates expression not only of plasminogen activator inhibitor type-1 (PAI-1), but also of the urokinase-type plasminogen activator receptor (uPAR), whose inhibition by specific antibodies blunted the TGFbeta angiogenic response in vitro. The SMAD2/3 and FAK signaling pathways were activated by TGFbeta in MVEC, as an early and late response, respectively. The use of two different TGFbeta1 antagonist peptides, derived from TGFbeta type III receptor sequence and 15-mer phage display technology, inhibited the signaling and pro-angiogenic response in vitro, as well as uPAR and PAI-1 up-regulation of MVEC following TGFbeta challenge. The anti-angiogenic properties of both inhibitors were evident also in the in vivo TGFbeta Matrigel Sponge Assay. These results may be relevant to develop a potentially fruitful strategy for the therapy of late-stage-associated tumor angiogenesis.
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PMID:TGFbeta1 antagonistic peptides inhibit TGFbeta1-dependent angiogenesis. 1904 49

While hypoxia-inducible factor (HIF) is a major actor in the cell survival response to hypoxia, HIF also is associated with cell death. Several studies implicate the HIF-induced putative BH3-only proapoptotic genes bnip3 and bnip3l in hypoxia-mediated cell death. We, like others, do not support this assertion. Here, we clearly demonstrate that the hypoxic microenvironment contributes to survival rather than cell death by inducing autophagy. The ablation of Beclin1, a major actor of autophagy, enhances cell death under hypoxic conditions. In addition, the ablation of BNIP3 and/or BNIP3L triggers cell death, and BNIP3 and BNIP3L are crucial for hypoxia-induced autophagy. First, while the small interfering RNA-mediated ablation of either BNIP3 or BNIP3L has little effect on autophagy, the combined silencing of these two HIF targets suppresses hypoxia-mediated autophagy. Second, the ectopic expression of both BNIP3 and BNIP3L in normoxia activates autophagy. Third, 20-mer BH3 peptides of BNIP3 or BNIP3L are sufficient in initiating autophagy in normoxia. Herein, we propose a model in which the atypical BH3 domains of hypoxia-induced BNIP3/BNIP3L have been designed to induce autophagy by disrupting the Bcl-2-Beclin1 complex without inducing cell death. Hypoxia-induced autophagy via BNIP3 and BNIP3L is clearly a survival mechanism that promotes tumor progression.
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PMID:Hypoxia-induced autophagy is mediated through hypoxia-inducible factor induction of BNIP3 and BNIP3L via their BH3 domains. 1927 85

Although evidence is accumulating for promising anticancer properties of host-defense peptides (HDPs), their potential therapeutic use suffers from limitations inherent to peptide pharmaceuticals, including poor bioavailability and potential toxicity. Therefore, we tested the hypothesis that HDP mimics might generate improved anticancer derivatives. Oligomers of acyl-lysyl (OAKs) varying with respect to charge, hydrophobicity, and backbone length were screened against prostate adenocarcinoma cell line TRAMP-C2 using the XTT assay. A promising 11-mer sequence, designated alpha(12)-3beta(12), was further characterized in terms of selectivity (using human primary fibroblasts and malignant cells), mechanism of action and its relation to multidrug resistance (using 7 ABC multidrug efflux transporters), and antitumor efficacy (as assessed in C57BL/6J mice bearing TRAMP-C2 tumors). The OAK exerted rapid and selective cytotoxicity against malignant cells, apparently via an intracellular multitarget mode of action, thereby overcoming major modalities of chemoresistance. Both systemic and local administrations of alpha(12)-3beta(12) to tumor-bearing mice significantly inhibited tumor progression and were associated with an improved toxicity profile when compared to doxorubicin. Moreover, a combination of alpha(12)-3beta(12) with doxorubicin can lead to tumor eradication. Collectively, the current findings establish the potential of an HDP-mimetic approach for developing simplified yet robust antitumor agents that bear a key advantage of overcoming MDR phenomena.
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PMID:Host-defense peptide mimicry for novel antitumor agents. 1970 28

Human LATS1 and LATS2) (LATS1/2) are tumor suppressors that have been shown to be mutated or downregulated in several human cancers including leukemia, lung, prostate and breast cancers. However, the precise mechanisms and the proteins modulated by LATS1/2 that are responsible for these events remain largely unknown. To elucidate potential signaling pathways, the current study investigated the expression profile in HeLa cells with reduced expression of LATS1/2. Using RNA-mediated interference, both LATS1 and LATS2 were substantially knocked-down, and accordingly, this lead to an increase in multiple phenotypes associated with tumor progression, including enhanced cell proliferation, resistance to drug-induced cell death, and increased cell migration. Using whole human genome Oligo (60-mer) arrays (Agilent), genes modulated by loss of LATS1/2 were identified and functionally grouped into categories including cell proliferation, cell death, cell adhesion and motility, as well as cell communication. Selected genes, including known tumor suppressor genes and oncogenes such as CDKN1A, WISP2, SLIT2, TP53INP1, BIRC4BP, SPRY2, SPRY4, SPRED1, FAT4, and CYR61 were confirmed by qRT-PCR to be significantly differentially expressed. Importantly, the collection of genes identified suggests that LATS1/2 function through diverse mechanisms and multiple signaling pathways including the Hippo signaling pathway, as well as the p53, Ras-ERK, or WNT networks, to inhibit tumor progression.
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PMID:Identification of LATS transcriptional targets in HeLa cells using whole human genome oligonucleotide microarray. 1979 73

Aberrant cell-surface glycosylation patterns are present on virtually all tumors and have been linked to tumor progression, metastasis, and invasivity. We have shown that expressing a normally quiescent, glycoprotein-specific alpha2,6-sialyltransferase (ST6Gal1) gene in gliomas inhibited invasivity in vitro and tumor formation in vivo. To identify other glycogene targets with therapeutic potential, we created a focused 45-mer oligonucleotide microarray platform representing all of the cloned human glycotranscriptome and examined the glycogene expression profiles of 10 normal human brain specimens, 10 malignant gliomas, and 7 human glioma cell lines. Among the many significant changes in glycogene expression observed, of particular interest was the observation that an additional alpha2,6-sialyltransferase, ST6 (alpha-N-acetyl-neuraminyl-2,3-beta-galactosyl-1,3)-N-acetylgalactosaminide alpha2,6-sialyltransferase 5 (ST6GalNAcV), was expressed at very low levels in all glioma and glioma cell lines examined compared with normal brain. ST6GalNAcV catalyzes the formation of the terminal alpha2,6-sialic acid linkages on gangliosides. Stable transfection of ST6GalNAcV into U373MG glioma cells produced (i) no change in alpha2,6-linked sialic acid-containing glycoproteins, (ii) increased expression of GM2alpha and GM3 gangliosides and decreased expression of GM1b, Gb3, and Gb4, (iii) marked inhibition of in vitro invasivity, (iv) modified cellular adhesion to fibronectin and laminin, (v) increased adhesion-mediated protein tyrosine phosphorylation of HSPA8, and (vi) inhibition of tumor growth in vivo. These results strongly suggest that modulation of the synthesis of specific glioma cell-surface glycosphingolipids alters invasivity in a manner that may have significant therapeutic potential.
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PMID:Overexpression of ST6GalNAcV, a ganglioside-specific alpha2,6-sialyltransferase, inhibits glioma growth in vivo. 2061 19

Acylpeptide hydrolase (APEH), one of the four members of the prolyl oligopeptidase class, catalyses the removal of N-acylated amino acids from acetylated peptides and it has been postulated to play a key role in protein degradation machinery. Disruption of protein turnover has been established as an effective strategy to down-regulate the ubiquitin-proteasome system (UPS) and as a promising approach in anticancer therapy.Here, we illustrate a new pathway modulating UPS and proteasome activity through inhibition of APEH. To find novel molecules able to down-regulate APEH activity, we screened a set of synthetic peptides, reproducing the reactive-site loop of a known archaeal inhibitor of APEH (SsCEI), and the conjugated linoleic acid (CLA) isomers. A 12-mer SsCEI peptide and the trans10-cis12 isomer of CLA, were identified as specific APEH inhibitors and their effects on cell-based assays were paralleled by a dose-dependent reduction of proteasome activity and the activation of the pro-apoptotic caspase cascade. Moreover, cell treatment with the individual compounds increased the cytoplasm levels of several classic hallmarks of proteasome inhibition, such as NFkappaB, p21, and misfolded or polyubiquitinylated proteins, and additive effects were observed in cells exposed to a combination of both inhibitors without any cytotoxicity. Remarkably, transfection of human bronchial epithelial cells with APEH siRNA, promoted a marked accumulation of a mutant of the cystic fibrosis transmembrane conductance regulator (CFTR), herein used as a model of misfolded protein typically degraded by UPS. Finally, molecular modeling studies, to gain insights into the APEH inhibition by the trans10-cis12 CLA isomer, were performed.Our study supports a previously unrecognized role of APEH as a negative effector of proteasome activity by an unknown mechanism and opens new perspectives for the development of strategies aimed at modulation of cancer progression.
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PMID:Acylpeptide hydrolase inhibition as targeted strategy to induce proteasomal down-regulation. 2201 82

Metastatic progression of cancer is a complex and clinically daunting process. We previously identified a set of human microRNAs (miRNAs) that robustly suppress breast cancer metastasis to lung and bone and which display expression levels that predict human metastasis. Although these findings revealed miRNAs as suppressors of cell-autonomous metastatic phenotypes, the roles of non-coding RNAs in non-cell-autonomous cancer progression processes remain unknown. Here we reveal that endogenous miR-126, an miRNA silenced in a variety of common human cancers, non-cell-autonomously regulates endothelial cell recruitment to metastatic breast cancer cells, in vitro and in vivo. It suppresses metastatic endothelial recruitment, metastatic angiogenesis and metastatic colonization through coordinate targeting of IGFBP2, PITPNC1 and MERTK--novel pro-angiogenic genes and biomarkers of human metastasis. Insulin-like growth factor binding protein 2 (IGFBP2) secreted by metastatic cells recruits endothelia by modulating IGF1-mediated activation of the IGF type-I receptor on endothelial cells; whereas c-Mer tyrosine kinase (MERTK) receptor cleaved from metastatic cells promotes endothelial recruitment by competitively antagonizing the binding of its ligand GAS6 to endothelial MERTK receptors. Co-injection of endothelial cells with breast cancer cells non-cell-autonomously rescues their miR-126-induced metastatic defect, revealing a novel and important role for endothelial interactions in metastatic initiation. Through loss-of-function and epistasis experiments, we delineate an miRNA regulatory network's individual components as novel and cell-extrinsic regulators of endothelial recruitment, angiogenesis and metastatic colonization. We also identify the IGFBP2/IGF1/IGF1R and GAS6/MERTK signalling pathways as regulators of cancer-mediated endothelial recruitment. Our work further reveals endothelial recruitment and endothelial interactions in the tumour microenvironment to be critical features of metastatic breast cancer.
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PMID:A microRNA regulon that mediates endothelial recruitment and metastasis by cancer cells. 2217 Jun 10

Human transferrin receptor 1 (TfR1) is expressed on malignant cells at levels several fold higher than those on normal cells and its expression can be correlated with tumor stage or cancer progression. It is a potentially rational target for drug delivery. To identify novel ligands which can recognize the TfR1 specifically, a random phage displayed 12-mer peptide library was screened and two consensus motifs of the peptides which are displayed by the positive phages RXR and RXXXR (x is any amino acid) were yield. The phage displaying peptide SPRPRHTLRLSL (designated as B18) exhibited the highest affinity to TfR1 in phage ELISA and B18 could bind to TfR1 specifically in a dose dependent manner. The flow cytometry assay and immunocellularchemistry assay showed that the B18 could bind to TfR1 positive carcinoma cells with specificity. In addition, the biodistribution assay indicated that B18 could home to TfR1 positive tumor tissue specifically. Our study suggests that the peptide exhibited by B18 is a potentially promising targeting peptide for tumor diagnosis and treatment.
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PMID:Identification of a novel peptide ligand of human transfrrin receptor 1 for targeted tumor delivery drug. 2267 Jul 65

Since its discovery in 1970, protein S (PS) has emerged as a key vitamin K-dependent natural anticoagulant protein at the crossroads of multiple biological processes, including coagulation, apoptosis, atherosclerosis, angiogenesis/vasculogenesis, and cancer progression. Following the binding to a unique family of protein tyrosine kinase receptors referred to as Tyro-3, Axl and Mer (TAM) receptors, PS can lead to regulation of coagulation, phagocytosis of apoptotic cells, cell survival, activation of innate immunity, vessel integrity and angiogenesis, and local invasion and metastasis. Because of these dynamics and multiple functions of PS, which are largely lost following invalidation of the mouse PROS1 gene, this molecule is currently intensively studied in biomedical research. The purpose of this review is to provide a brief chronicle of the discovery and current understanding of the mechanisms of PS signaling, and how PS and their signaling partners regulate various cellular functions, with a particular focus on TAM receptors.
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PMID:Protein S: A multifunctional anticoagulant vitamin K-dependent protein at the crossroads of coagulation, inflammation, angiogenesis, and cancer. 2395 77


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