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

Proteases play causal roles in the malignant progression of human tumors. This review centers on the roles in this process of cysteine cathepsins, i.e., peptidases belonging to the papain family (C1) of the CA clan of cysteine proteases. Cysteine cathepsins, most likely along with matrix metalloproteases (MMPs) and serine proteases, degrade the extracellular matrix, thereby facilitating growth and invasion into surrounding tissue and vasculature. Studies on tumor tissues and cell lines have shown changes in expression, activity and distribution of cysteine cathepsins in numerous human cancers. Molecular, immunologic and pharmacological strategies to modulate expression and activity of cysteine cathepsins have provided evidence for a causal role for these enzymes in tumor progression and invasion. Clinically, the levels, activities and localization of cysteine cathepsins and their endogenous inhibitors have been shown to be of diagnostic and prognostic value. Understanding the roles that cysteine proteases play in cancer could lead to the development of more efficacious therapies.
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PMID:Cysteine cathepsins in human cancer. 1557 21

The CCN family of growth factors is composed of six structurally related proteins including the cysteine-rich 61 (Cyr61), connective tissue growth factor (CTGF), nephroblastoma overexpressed (NOV), Wnt-1 induced secreted protein-1 (WISP-1), WISP-2 and WISP-3. Each family member consists of four conserved cysteine rich modular domains with sequence similarity to the insulin like growth factor binding proteins, von Willebrand factor, thrombospondin repeat and the growth factors cysteine knot. The CCN proteins demonstrate a wide variety of biological activities regulating cell adhesion, proliferation, survival, migration, invasion in vitro and tumorigenesis and angiogenesis in vivo. Both cancer promoting and inhibiting roles were proposed for several CCN proteins suggesting that contextual factors could regulate their activities. Consistent with this hypothesis, structural and experimental evidence indicate that the function of these proteins is modulated by their interaction with sulfated glycosaminoglycans. Because the CCN proteins are implicated in the tumorigenic process, they are potential targets for the development of cancer therapeutics. Modulation of their glycosaminoglycan interaction by exogenous, highly sulfated polysaccharides, oligosaccharides or glycosaminoglycan mimetics could prevent their participation in cancer progression. Understanding the structural requirements for their polysaccharide interaction should provide important information to generate glycosaminoglycan-based cancer therapeutics targeting the CCN family of proteins.
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PMID:Structural basis and therapeutic implication of the interaction of CCN proteins with glycoconjugates. 1638 Nov 2

Experimental in vivo tumor models are essential for comprehending the dynamic process of human cancer progression, identifying therapeutic targets, and evaluating antitumor drugs. However, current rodent models are limited by high costs, long experimental duration, variability, restricted accessibility to the tumor, and major ethical concerns. To avoid these shortcomings, we investigated whether tumor growth on the chick chorio-allantoic membrane after human glioblastoma cell grafting would replicate characteristics of the human disease. Avascular tumors consistently formed within 2 days, then progressed through vascular endothelial growth factor receptor 2-dependent angiogenesis, associated with hemorrhage, necrosis, and peritumoral edema. Blocking of vascular endothelial growth factor receptor 2 and platelet-derived growth factor receptor signaling pathways by using small-molecule receptor tyrosine kinase inhibitors abrogated tumor development. Gene regulation during the angiogenic switch was analyzed by oligonucleotide microarrays. Defined sample selection for gene profiling permitted identification of regulated genes whose functions are associated mainly with tumor vascularization and growth. Furthermore, expression of known tumor progression genes identified in the screen (IL-6 and cysteine-rich angiogenic inducer 61) as well as potential regulators (lumican and F-box-only 6) follow similar patterns in patient glioma. The model reliably simulates key features of human glioma growth in a few days and thus could considerably increase the speed and efficacy of research on human tumor progression and preclinical drug screening.
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PMID:Accessing key steps of human tumor progression in vivo by using an avian embryo model. 1566

Particularly interesting new cysteine-histidine-rich protein (PINCH), a LIM domain adapter protein that functions in the integrin and growth factor signal transduction pathway, is upregulated in stroma associated with many common cancers. The finding suggested that PINCH may be involved in promoting tumor-stromal interactions that support tumor progression, and, if so, tumors with abundant PINCH stromal staining may have a worse prognosis. To test this hypothesis, 174 primary colorectal adenocarcinomas with 39 distant normal mucosa samples and 26 metastases in the lymph nodes were studied by immunohistochemistry, and 7 additional colon tumors were studied by Western blot analysis and immunofluorescence. The abundance of PINCH protein in stroma increased from normal mucosa to primary tumor to metastasis (P <.05), and was more intense at the invasive margin than it was in the intratumoral stroma. Strong stromal immunostaining for PINCH was shown to predict a worse outcome (rate ratio 2.1, 95% CI 1.16-3.37, P=.01), independent of Dukes stage, growth pattern, and tumor differentiation. PINCH was detected in fibroblasts, myofibroblasts, and a proportion of endothelial cells of the tumor vasculature, supporting the involvement of PINCH in promoting tumor-stromal interactions that support tumor progression. Interestingly, stromal staining for PINCH was an independent prognostic indicator in colorectal cancer.
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PMID:Stromal staining for PINCH is an independent prognostic indicator in colorectal cancer. 1572 Aug 6

Laser capture microdissection (LCM) provides the capability to isolate and analyze small numbers of cells from a specific area of a histologic section. LCM has particular value for analysis of early stage tumors, which are often small and intermixed with non-tumor tissue. It has previously been shown that a new generation of cysteine-reactive cyanine dyes can, in principle, provide increased sensitivity for two-dimensional fluorescence difference gel electrophoresis (2-D DIGE) profiling when sample quantitities are limiting. However, the comparative advantage of the new dyes in a clinical setting has not been established. Here, we report that cysteine-reactive dyes allowed the identification of more features than established, lysine-reactive dyes with a given number of cells. This was true both with extracts prepared from human papillomavirus E6 and E7-transduced human keratinocytes, a model for early-stage cervical cancer, and with LCM samples. In an experiment comparing LCM clinical samples of gastric adenocarcinoma versus precancerous, spasmolytic polypeptide expressing metaplasia (SPEM) from the same patient, cysteine labeling allowed the identification of more than 1000 discrete protein spots in samples containing 5000 cells. This is a 5- to 50-fold smaller sample than used in previous studies. Both labeling methods had a comparable success rate for protein identification by mass spectrometry (MS). The proteins associated with more than 40 differentially abundant spots in the clinical samples were identified by MS. In this exploratory analysis, changes in expression levels of cytoskeletal proteins, molecular chaperones, and cell-signaling proteins were seen. The identification of a number of proteins that are potentially relevant to tumor progression suggests that the method holds promise for biomarker discovery.
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PMID:Saturation labeling with cysteine-reactive cyanine fluorescent dyes provides increased sensitivity for protein expression profiling of laser-microdissected clinical specimens. 1576 55

N-acetyl-cysteine (NAC) has been reported to have anticancer properties such as counteractions against mutagens and prevention of tumor progression by scavenging reactive oxygen species (ROS). However, here we report that NAC can enhance the anchorage-independent growth of cells transformed by activated ABL tyrosine kinases or Ras. This effect was not dependent on loss of focal adhesion kinase activation. NAC rescued cell growth that was suppressed by heat shock protein (Hsp) 90 inhibitors possibly by chemical modification of their quinone moiety. NAC rendered Rat1/BCR-ABL cells resistance to a Ras inhibitor manumycin in soft agar colony formation. In the absence of Hsp90 inhibitors, NAC stimulated the activation of MAP kinase in BCR-ABL-transformed but not in the parental Rat1 cells. We propose that NAC should be used carefully in cancer treatment.
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PMID:N-acetyl-cysteine enhances growth in BCR-ABL-transformed cells. 1581 23

Endogenous cysteine proteases were given much attention lately, as their role in a variety of pathophysiological disorders became evident. Amongst them cathepsins, which are thought to be implicated in mediation of osteoporosis, cancer progression, atherosclerosis, and many other conditions, are of considerable interest as drug targets. In the presented work, papain was chosen as a model cysteine protease and panning protocol was optimized for selection of papain-binding phage-displayed peptides from a commercially available combinatorial peptide library. Different selection strategies were applied in order to select high-affinity binders. Ultimately, five cyclic peptides (CNWAAGYNCGGGS-NH2, CWSMMGFQCGGGS-NH2, CWEWGGWHCGGSS-OH, CNWTLGGYKCGGGS-NH2 (all cyclized through formation of intramolecular disulphide bond), and GNWTLGGYKGG (cyclized head-to-tail)) were synthesized and tested for inhibitory activity towards papain and human cathepsins L, B, H, and K. The peptides possess inhibitory constants in the low micromolar to mid-nanomolar range and exhibit certain selectivity for different lysosomal cysteine proteases included in this study.
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PMID:Affinity selection to papain yields potent peptide inhibitors of cathepsins L, B, H, and K. 1591 50

Protein Kinase Balpha(PKBalpha, or Akt1) is believed to play a crucial role in programmed cell death, cancer progression and the insulin-signaling cascade. The protein is activated by phosphorylation at multiple sites and subsequently phosphorylates and activates eNOS. Free cysteine residues of the protein may capture reactive, endogenously produced nitric oxide (NO) as S-nitrosothiols. Site-specific detection of S-nitrosylated cysteine residues, usually at low stoichiometry, has been a major challenge in proteomic research largely due to the lack of mass marker for S-nitrosothiols that are very labile under physiologic conditions. In this report we describe a sensitive and specific MS method for detection of S-nitrosothiols in PKB alpha/Akt1 in rat soleus muscle. PKB alpha/Akt1 was isolated by immunoprecipitation and 2D-gel electrophoresis, subjected to in-gel tryptic digestion, and cysteinyl nitrosothiols were reacted with iodoacetic acids [2-C(12)/C(13) = 50/50] under ascorbate reduction conditions. This resulted in the production of relatively stable carboxymethylcysteine (CMC) immonium ions (m/z 134.019 and m/z 135.019) within a narrow argon collision energy (CE = 30 +/- 5 V) in the high MS noise region. In addition, free and disulfide-linked cysteine residues were converted to carboxyamidomethylcysteines (CAM). Tryptic S-nitrosylated parent ion was detected with a mass accuracy of 50 mDa for the two CMC immonium ions at the triggered elution time during capillary liquid chromatography (LC) separation. A peptide containing Cys(296) was discriminated from four co-eluting tryptic peptides under lock mass conditions (m/z 785.8426). S-nitrosothiol in the tryptic peptide, ITDFGLBKEGIK (B: CAM, [M + 2H](2+) = 690.86, Found: 690.83), is believed to be present at a very low level, since the threshold for the CMC immonium trigger ions was set at 3 counts/s in the MS survey. The high levels of NO that are produced under stress conditions may result in increased S-nitrosylation of Cys(296) which blocks disulfide bond formation between Cys(296) and Cys(310) and suppresses the biological effects of PKB alpha/Akt1. With the procedures developed here, this process can be studied under physiological and pathological conditions.
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PMID:Site-specific detection of S-nitrosylated PKB alpha/Akt1 from rat soleus muscle using CapLC-Q-TOF(micro) mass spectrometry. 1604 29

The lysosomal aspartic protease cathepsin D (cath-D) is over-expressed and hyper-secreted by epithelial breast cancer cells. This protease is an independent marker of poor prognosis in breast cancer being correlated with the incidence of clinical metastasis. Cath-D over-expression stimulates tumorigenicity and metastasis. Indeed it plays an essential role in the multiple steps of tumor progression, in stimulating cancer cell proliferation, fibroblast outgrowth and angiogenesis, as well as in inhibiting tumor apoptosis. A mutated cath-D devoid of catalytic activity still proved mitogenic for cancer, endothelial and fibroblastic cells, suggesting an extra-cellular mode of action of cath-D involving a triggering, either directly or indirectly, of an as yet unidentified cell surface receptor. Cath-D is also a key mediator of induced-apoptosis and its proteolytic activity has been involved generally in this event. During apoptosis, mature lysosomal cath-D is translocated to the cytosol. Since cath-D is one of the lysosomal enzymes which requires a more acidic pH to be proteolytically-active relative to the cysteine lysosomal enzymes, such as cath-B and -L, it is open to question whether cytosolic cath-D might be able to cleave substrate(s) implicated in the apoptotic cascade. This review summarises our current knowledge on cath-D action in cancer progression and metastasis, as well as its dual function in apoptosis.
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PMID:Cathepsin D: newly discovered functions of a long-standing aspartic protease in cancer and apoptosis. 1604 58

We recently reported that proteinase-activated receptors type I (PAR-1) are coupled to both negative and positive invasion pathways in colonic and kidney cancer cells cultured on collagen type I gels. Here, we found that treatments with the cell-permeant analog 8-Br-cGMP and the soluble guanylate cyclase activator BAY41-2272, and Rho kinase (ROK) inhibition by Y27632 or a dominant negative form of ROK lead to PAR-1-mediated invasion through differential Rac1 and Cdc42 signaling. Hypoxia or the counteradhesive matricellular protein SPARC/BM-40 (SPARC: secreted protein acidic rich in cysteine) overexpressed during cancer progression also commutated PAR-1 to cellular invasion through the cGMP/protein kinase G (PKG) cascade, RhoA inactivation, and Rac1-dependent or -independent signaling. Cultured primary cancer cells isolated from peritoneal and pleural effusions from patients with colon cancer or other malignant tumors harbored PAR-1, as shown by RT-PCR and FACS analyses. These malignant effusions also contained high levels of activated thrombin and fibrin, and induced a proinvasive response in HCT8/S11 human colorectal cancer cells. Our data underline the essential role of the tumor microenvironment and of several commutators targeting cGMP/PKG signaling and the RhoA-ROK axis in the control of PAR-1 proinvasive activity and metastatic potential of cancer cells in distant organs and peritoneal or pleural cavities. We also add new insights into the mechanisms linking the coagulation mediators thrombin and PAR-1 in the context of blood coagulation disorders and venous thrombosis often observed in cancer patients, as described in 1865 by Armand Trousseau.
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PMID:Commutators of PAR-1 signaling in cancer cell invasion reveal an essential role of the Rho-Rho kinase axis and tumor microenvironment. 1609 33


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