Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Polyacrylamide gel electrophoresis is an extremely powerful tool for separating and analyzing protein associated with different diseases and has been invaluable in the identification and analysis of proteins associated with characteristics unique to tumor cells. This study presents data demonstrating the application of conventional sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis and substrate-incorporated SDS-polyacrylamide gel electrophoresis (zymography) to obtain information about the proteins and catalytically active (or activatable) proteases associated with the process of tumor cell invasion using established human melanoma and breast carcinoma cell lines. Conventional SDS-polyacrylamide gel electrophoresis was used to show that cells sequentially selected from a low invasive human melanoma cell line on the basis of their ability to invade in vitro have an increase and/or addition of six unique proteins on their cell surface. In a different application of SDS-polyacrylamide gel electrophoresis, zymography was used to demonstrate that there is an increase in the levels of gelatinase A in the conditioned medium from three differently invasive human melanoma cell lines coincident with their ability to invade in vitro. Furthermore, the conditioned medium from the most invasive melanoma cell line demonstrated the greatest amount of gelatinase B activity. While the conditioned medium from three human breast carcinoma cell lines contained low levels of both gelatinase A and B, one breast cell line also contained activity associated with stromelysin(s) not seen in the melanoma cell lines.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Electrophoretic analysis of proteins associated with tumor cell invasion. 805 71

Members of the matrix metalloproteinase (MMP) family have been implicated in disease states such as arthritis, periodontal disease, and tumor cell invasion and metastasis. Stromelysin 1 (MMP-3) has a broad substrate specificity and participates in the activation of several MMP zymogens. We examined known sequences of MMP-3 cleavage sites in natural peptides and proteins and compared sequence specificities of MMP-3 and interstitial collagenase (MMP-1) in order to design fluorogenic substrates that (i) would be hydrolyzed rapidly by MMP-3, (ii) would discriminate between MMP-3 and MMP-1, and (iii) could be monitored continuously without interference from MMP amino acid residues. Designed substrates were then screened for activity toward MMP-1, gelatinase A (MMP-2), MMP-3, and gelatinase B (MMP-9). The first of these substrates, NFF-1 (Mca-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Lys-(Dnp)-Gly, where Mca is (7-methoxycoumarin-4-yl)acetyl and Dnp is 2,4-dinitrophenyl), was hydrolyzed equally well by MMP-3 and MMP-2 (kcat/Km approximately 11,000 s-1 M-1). MMP-1 had 25% of the activity of MMP-3 toward NFF-1. The second substrate, NFF-2 (Mca-Arg-Pro-Lys-Pro-Tyr-Ala-Nva-Trp-Met-Lys(Dnp)-NH2, where Nva is norvaline), was hydrolyzed 60 times more rapidly by MMP-3 (kcat/Km = 59,400 s-1 M-1) than MMP-1. Unfortunately, NFF-2 showed little discrimination between MMP-3, MMP-2 (kcat/Km = 54,000 s-1 M-1), and MMP-9 (kcat/Km = 55,300 s-1 M-1). The third substrate, NFF-3 (Mca-Arg-Pro-Lys-Pro-Val-Glu-Nva-Trp-Arg-Lys(Dnp)-NH2), was hydrolyzed rapidly by MMP-3 (kcat/Km = 218,000 s-1 M-1) and very slowly by MMP-9 (kcat/Km = 10,100 s-1 M-1), but there was no significant hydrolysis by MMP-1 and MMP-2. NFF-3 is the first documented synthetic substrate hydrolyzed by only certain members of the MMP family and thus has important application for the discrimination of MMP-3 activity from that of other MMPs. Although NFF-3 was designed by assuming that substrate subsites were independent and hence free energy changes derived from single mutation experiments were additive, we found discrepancies between predicted and experimental kcat/Km values, one on the order of 2000-5000. Thus, the design of additional discriminatory MMP substrates may require approaches other than assuming additive free energy changes, such as screening synthetic libraries and consideration of secondary and tertiary structures of substrates and the enzyme.
 ...
PMID:Design and characterization of a fluorogenic substrate selectively hydrolyzed by stromelysin 1 (matrix metalloproteinase-3). 806 13

The metalloproteinase matrilysin is widely expressed in the epithelial tumor cells of malignant colorectal adenocarcinomas. Approximately 50% of benign adenomas also express low levels of matrilysin that is focally localized. The expression of stromelysin-1, stromelysin-3, and gelatinase A was observed in the stromal component of several carcinomas and was not present in adenomatous tissue. The expression of interstitial collagenase and gelatinase B was observed in occasional adenomas and carcinomas. Stromelysin-2 transcripts were not detectable in any of the samples examined. Tissue inhibitor of metalloproteinase-1 gene expression was widespread and was observed in both epithelial and stromal cells of adenomas and carcinomas. These results indicate that matrilysin gene expression is an early event in colorectal tumorigenesis and that the expression of stromelysin-1, stromelysin-3, and gelatinase A is primarily a late event. The observed gene expression patterns suggest that matrilysin may participate in early events in tumor progression and that multiple members of the metalloproteinase family may work in concert to facilitate late-stage tumor invasion and metastasis.
 ...
PMID:Expression and localization of matrix-degrading metalloproteinases during colorectal tumorigenesis. 806 80

Using specific cDNAs isolated from mouse fibroblasts we determined tissue-specific expression of different matrix metalloproteinase genes: both stromelysin-1 and collagenase IV are highly expressed in heart and lung, whereas collagenase I is expressed most abundantly in skeletal muscle, kidney, and bone. High basal level expression of stromelysin-2 is found in heart and kidney. Like in man and rat, the expressions of collagenase I, stromelysin-1, and stromelysin-2 are regulated by the tumor promoter 12-O-tetradecanoyl-phorbol 13-acetate and by UV irradiation, but not by cAMP. In contrast, the expression of the 72-kDa collagenase IV is not affected by either stimuli. We and others have shown previously that under cell culture conditions, the regulation of human collagenase I is regulated by the transcription factor Fos/Jun (AP-1). Here we show that in c-fos transgenic mice transcription of collagenase I is induced in thymus, spleen, and, most dominantly, in bone upon overexpression of Fos. Neither collagenase IV nor stromelysin-1 or stromelysin-2 expression is affected by c-Fos. The sites of induced collagenase I expression correlate with the sites of Fos-induced long-term cellular alterations in transgenic mice including bone remodeling and T cell development. In fact, in the developing bone tumors strongly enhanced levels of collagenase I transcripts were detectable. These results identify collagenase I as a Fos-regulated gene in vivo and suggest a possible role for Fos/Jun heterodimers in establishing the pathological phenotype of c-fos transgenic mice.
 ...
PMID:Phenotypic alterations in fos-transgenic mice correlate with changes in Fos/Jun-dependent collagenase type I expression. Regulation of mouse metalloproteinases by carcinogens, tumor promoters, cAMP, and Fos oncoprotein. 814 18

Members of the matrix metalloproteinase (MMP) family have been implicated in the metastasis of tumor cells, but no direct evidence linking any given member of the MMP family to metastatic behavior has been presented. Rat embryo cells transformed by the Ha-ras and v-myc oncogenes or by Ha-ras alone are metastatic in nude mice and release the 92-kDa gelatinase/collagenase (MMP-9), whereas those transformed by Ha-ras plus the adenovirus E1A gene are not metastatic and do not release MMP-9. Here we demonstrate that MMP-9 expression can be induced in these tumorigenic but nonmetastatic rat cells by transfection with an MMP-9 expression vector. Transfection of a MMP-9 expression vector, but not control DNAs, conferred metastatic capacity on the nonmetastatic cells. The majority of colonies isolated after continued passage either in vivo or in vitro had lost the MMP-9 expression vector. However, occasional cells were isolated from metastases which retained MMP-9 expression after passage. These cells retained metastatic capacity. In contrast, cells isolated after losing MMP-9 expression also lost the ability to metastasize. These results provide direct evidence that MMP-9 has a role in tumor metastasis.
 ...
PMID:Direct evidence linking expression of matrix metalloproteinase 9 (92-kDa gelatinase/collagenase) to the metastatic phenotype in transformed rat embryo cells. 818 3

Liarozole fumarate (R85,246), a novel benzimidazole derivative, reduced s.c. and bone metastasis tumor growth by the androgen-independent PC-3ML-B2 human prostatic carcinoma clone in SCID mice. The drug inhibited cell invasion of Matrigel in Boyden chamber chemotactic assays and the secretion of type IV collagenase. In vitro, liarozole failed to inhibit cell proliferation and cell attachment to various substrates (Matrigel, laminin, type IV collagen, and fibronectin). In vivo, the drug also blocked type IV collagenase production in established s.c. tumors. Liarozole has been postulated by others (R. De Coster, W. Wouters, R. Van Ginckel, D. End, et al. J. Steroid Biochem. Mol. Biol., 43: 197-201, 1992) to inhibit retinoic acid catabolism. Our data indicate that liarozole treatment can increase the tumor retinoic acid levels in vivo. Studies of retinoic acid revealed that the drug independently reduced tumor growth in vivo and inhibited cell invasion of Matrigel and the secretion of collagenase IV. Surprisingly, liarozole and retinoic acid failed to exhibit measurable synergistic activity both in vitro and in vivo. Taken together these data suggest that liarozole might inhibit retinoic acid catabolism in vivo and consequently have significant therapeutic value as an anti-prostatic tumor agent.
 ...
PMID:Liarozole and 13-cis-retinoic acid anti-prostatic tumor activity. 831 15

Type IV collagenases have been shown to play an important role in tumor metastasis and wound healing. In the present study, we have demonstrated the presence of 72-kDa and 92-kDa forms of type IV collagenase in human skin by biochemical and in situ hybridization techniques. In situ hybridization allowed us to localize the 72-kDa form mostly to fibroblasts and the 92-kDa form to the epidermis and endothelial cells. The presence of type IV collagenase was confirmed by Western blotting. Enzyme activity was assayed in spontaneous blisters (18 subjects) and suction-induced blisters (29 subjects) by the zymography method, and by using type IV collagen as the substrate. Thus, it was possible to detect both the 92-kDa and 72-kDa forms in spontaneous and induced blisters. An especially high level of the 92-kDa enzyme was found in a bullous pemphigoid patient. Type IV collagenases were studied during re-epithelialization of the blister, using the suction-blister model. There was a marked induction of the 92-kDa type that was confirmed to be in the regenerating, migratory, epithelium by in situ hybridization studies. These results indicate that 92-kDa type IV collagenase may play an essential role in the normal physiology and integrity of the skin and may be an important regulator of re-epithelialization. It was also shown that potent topical glucocorticoid down-regulated the 92-kDa type collagenase, suggesting that glucocorticoids may have a beneficial role in some skin diseases by decreasing type IV collagenase activity and, thus, reducing tissue destruction.
 ...
PMID:Demonstration of 72-kDa and 92-kDa forms of type IV collagenase in human skin: variable expression in various blistering diseases, induction during re-epithelialization, and decrease by topical glucocorticoids. 834 22

A new cultured cell line (KG-2) derived from human renal cell carcinoma and a metastatic model in nude mice were studied. KG-2 was cultured from renal cell carcinoma (clear cell carcinoma) of the left kidney. In vitro doubling time of KG-2 was approximately 50 hours. KG-2 cells produced tumors in both the subcutaneous and renal sub-capsular space in nude mice, with tumorigenicity of 75%, showing no difference between the two sites. Histologically, tumors formed in the subcutaneous sites were hypovascular granular cell carcinoma. Moreover, each tumor was encapsulated by a thick fibrous capsule and never produced distant metastasis or invasion into the surrounding tissue. However, tumors formed in the subrenal capsular space were clear cell carcinoma. These tumors were hypervascular, and produced distant metastases. The most common metastatic site was the lung. Immunohistochemical analysis using anti-human collagenase type IV antibody on tumors formed in subcutaneous and subrenal capsular sites demonstrated that the expression of this enzyme in tumors formed in the subrenal capsular space was much higher than that in tumors formed in the subcutaneous site. Additionally, immunohistochemical study using anti-mouse collagen type IV antibody, a major components of the vascular wall, demonstrated many small densely growing vessels in tumors formed in the subrenal capsular space. In contrast, few vessels were produced in tumors formed in subcutaneous sites. These findings suggest that factors relating to the different injection sites may regulate the production of collagenase type IV secreted by KG-2 cells and neovascularity in nude mice. This metastatic model may be useful in the study of the mechanism of cancer metastases.
 ...
PMID:[Establishment and characterization of a new human renal cell carcinoma cell line (KG-2) and metastatic model in nude mice]. 834 19

Two members of the matrix metalloproteinase family of enzymes, interstitial collagenase and 92-kDa gelatinase, have been implicated in the pathogenesis of rheumatoid arthritis and tumor metastasis. In order to characterize the activities of these enzymes, we have developed a fluorogenic peptide substrate which is efficiently hydrolyzed by both enzymes. This substrate was developed based on the addition of the fluorescent tag, N-methyl-anthranilic acid (Nma), to several previously synthesized substrates that had been evaluated with respect to their turnover by interstitial collagenase. One substrate, Dnp-Pro-Cha-Gly-Cys(Me)-His-Ala-Lys-(Nma)-NH2, had favorable solubility characteristics, was > 98% quenched, and produced a single cleavage product, Dnp-Pro-Cha-Gly, with a high fluorescence yield with both interstitial collagenase and 92-kDa gelatinase. Since the assay depends on measurement of increases in fluorescence, the position of the Nma group also proved to be important for optimization of the fluorescence signal. The assay is free from interference by organomercurial compounds and the cleavage product has excitation and emission spectra compatible with filters commonly available on commercial plate readers. The assay has been adapted to a 96-well format and provides a rapid screening protocol for the evaluation of inhibitors of these enzymes.
 ...
PMID:A high throughput fluorogenic substrate for interstitial collagenase (MMP-1) and gelatinase (MMP-9). 836 16

Forty-two cases of malignant lymphomas were studied for the expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) by Northern blot and in situ hybridization. The lymphomas were classified according to Working Formulation classification (25 high grade, 15 low grade, and 2 intermediate grade). The MMPs studied included: 72-kDa and 92-kDa gelatinases (type IV collagenases), interstitial collagenase, PUMP-1 (MMP-7), and stromelysins 1 and 3. TIMPs included TIMP-1 and TIMP-2. All but one case expressed TIMP-1, and TIMP-2 transcripts were detected in 35 cases. Among the MMPs, 92-kDa gelatinase was expressed most consistently (35 cases), whereas mRNA transcripts of 72-kDa gelatinase, interstitial collagenase, and PUMP-1 were detected in only a few cases. Stromelysins 1 and 3 mRNAs were not detected in any of the tumors studied. However, marked differences in the level of expression of certain MMPs and TIMPs were found among different grades of malignant lymphomas. The low grade tumors expressed low and relatively constant levels of TIMP-1, TIMP-2, and 92-kDa gelatinase transcripts, whereas high grade lymphomas displayed variable amounts of mRNAs for TIMPs and MMPs, with a trend toward elevated TIMP-1 and 92-kDa gelatinase mRNA levels. In situ hybridization localized TIMP-1 transcripts to stromal cells, while 92-kDa gelatinase transcripts were most abundant in "starry sky" macrophages and large lymphoma cells. Zymography showed that active 92-kDa gelatinase is present in tumor protein extracts and differences in the level of the enzymatic activity were seen between low and high grade lymphomas. Our data indicate that 92-kDa gelatinase and TIMP-1 expression by human malignant lymphomas may play an important role in controlling their biologic aggressiveness.
 ...
PMID:Patterns of expression of metalloproteinases and their inhibitors in human malignant lymphomas. 836 72


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>