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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Three stable carcinoma cell lines, designated PLS10, PLS20 and PLS30, have been established from 3,2'-dimethyl-4aminobiphenyl plus testosterone-induced carcinomas in the dorsolateral prostate of male F344 rats. The cells are keratin-positive and grow as typical epithelial monolayers in culture. When injected into intact male nude mice, PLS10 and PLS30 cells form well-differentiated adenocarcinomas with abundant connective tissue stroma, while PLS20 cells give rise to poorly differentiated adenocarcinomas. Growth of all PLS cell lines in nude mice is not affected by castration and the cells are immunohistochemically negative for androgen receptors. Tumor growth rates in nude mice were found to be PLS20 > PLS10 > PLS30, with significant in vitro stimulation by insulin/transferrin, but not epidermal growth factor, dexamethasone or basic fibroblast growth factor. Spontaneous lung metastases were observed in all cases. However, skeletal invasion including bone is essentially observed only with the PLS20 tumors. Gelatin zymography showed predominant secretion of the active form of gelatinase B (Mr 92,000 type IV collagenase) by all the cell lines. Karyotype analysis revealed PLS10, PLS30 and PLS20 to be diploid, hyperdiploid and hypertetraploid, respectively. The results demonstrate that the three PLS cell lines are androgen-independent and metastatic in common, but have different histology, growth potential and invasiveness. They may therefore be useful models for understanding progression and metastasis of human prostatic carcinomas.
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PMID:Establishment and characterization of three androgen-independent, metastatic carcinoma cell lines from 3,2'-dimethyl-4-aminobiphenyl-induced prostatic tumors in F344 rats. 904 56

The expression of extracellular-matrix (ECM)-degrading proteases has been shown to be necessary for invasion of tumor cells into surrounding tissue. For several tumor types, overexpression of these proteases is dependent upon interactions with adjacent fibroblast cell populations. We previously demonstrated activation of matrix metalloprotease (MMP) and urokinase-type plasminogen activator (uPa) expression in a coculture model consisting of squamous cell carcinoma cells (SCC) with dermal fibroblasts. In the present study we have examined whether melanocytes, which are known to interact closely with keratinocytes of the basal epidermal layer, might influence ECM-degrading protease expression in SCC cells as well. Upon coculture of the human SCC cell line II-4 with the nontumorigenic mouse melanocyte cell line Melan-a or treatment of II-4 cells with Melan-a conditioned media, induction of expression of the MMP matrilysin and uPa was observed. In contrast, no induction was observed for stromelysin-1 or 92-kDa type IV collagenase. Matrilysin/uPa-inducing activity was found to act at the level of gene transcription for both matrilysin and uPa and was ubiquitously expressed among six different human melanocytic cell strains/lines, ranging from primary normal melanocytes to cell lines established from metastatic melanoma lesions. These data demonstrate that melanocytic cells can exert a paracrine influence in SCC cells on the expression of specific proteases involved in ECM turnover and tumor invasiveness.
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PMID:Melanocyte mediated paracrine induction of extracellular matrix degrading proteases in squamous cell carcinoma cells. 905 12

In this study, we describe the activity of CT1746, an orally-active synthetic MMP inhibitor that has a greater specificity for gelatinase A, gelatinase B and stromelysin than for interstitial collagenase and matrilysin, in a nude mouse model that better mimics the clinical development of human colon cancer. The model is constructed by surgical orthotopic implantation (SOI) of histologically-intact tissue of the metastatic human colon tumor cell line Co-3. Animals were gavaged with CT1746 twice a day at 100 mg/kg for 5 days after the SOI of Co-3 for 43 days. In this model CT1746 significantly prolonged the median survival time of the tumor-bearing animals from 51 to 78 days. Significant efficacy of CT1746 was observed on primary tumor growth (32% reduction in mean tumor area at day 36), total spread and metastasis (6/20 treated animals had no detectable spread and metastasis at autopsy compared to 100% incidence of secondaries in control groups). Efficacy of CT1746 could also be seen on reducing tumor spread and metastasis to individual organ sites such as the abdominal wall, cecum and lymph nodes compared to vehicle and untreated controls. We conclude that chronic administration of a peptidomimetic MMP inhibitor via the oral route is feasible and results in inhibition of solid tumor growth, spread and metastasis with increase in survival in this model of human cancer, thus converting aggressive cancer to a more controlled indolent disease.
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PMID:Conversion of highly malignant colon cancer from an aggressive to a controlled disease by oral administration of a metalloproteinase inhibitor. 906 95

Correlative and functional evidence support a crucial role for metalloproteinase (MMP) activity in tumor progression. Dysregulation of MMP production at local tumor sites is thought to participate in the remodeling of the local stromal tissue necessary for tumor growth. The extent of damages in local tissues is often reflected by the high concentration of MMP released in the bloodstream of cancer patients. The integrity of the thymic architecture plays a crucial role in the development of mature T cells, but it is compromised by extensive remodeling occurring during the development of thymic lymphomas. In the present work, we have used an experimental thymic lymphoma model to investigate the regulation of MMP-9 (gelatinase B) production in animals bearing large thymic lymphomas. We show a 3-fold increase in serum gelatinase B (Gel B) levels in animals bearing thymic lymphoma compared with those found in normal animals and a correlation between these levels and the size of the tumor. Although Gel B was found within the thymic tumor, lymphoma cells did not express it in vivo, indicating that Gel B expression was associated with thymic stromal cells rather than lymphoma cells. This was corroborated by evidence that lymphoma cells have the capacity to stimulate Gel B gene expression in stromal cells. Our results suggest that lymphoma cells can exert a significant control over Gel B expression by local stromal cells, thereby inducing the extensive remodeling necessary for tumor growth.
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PMID:Gelatinase B (MMP-9) production and expression by stromal cells in the normal and adult thymus and experimental thymic lymphoma. 909 68

We have developed a novel murine mammary tumor system with variants representing different stages of tumor progression. The MXT-s parental cell line was established from a urethane-induced and hormone-sensitive mammary tumor. MXT-s parental cells are highly tumorigenic but poorly metastatic. MXT clones and variants were selected by either in vitro or in vivo procedures, and they differ in metastatic ability and 17 beta-estradiol dependency for tumor growth. The MXT-c1.1 and MXT-B2 cell lines produced lung metastasis after intravenous injection into 100% of syngenic mice, but only MXT-c1.1 cells were highly metastatic from intramammary tumors. The fingerprints obtained by arbitrarily primed-polymerase chain reaction demonstrated that the metastatic variants and clones had a common genetic background and resulted from clonal selection from the parental cell line. We studied whether the matrix metalloproteinase (MMP) profile is correlated with tumor progression and metastatic ability in the MXT tumor system. Gelatinases A and B were assayed in the cells, both by enzyme activity and mRNA expression. Gelatinase A was expressed in MXT-c1.1 cells, whereas MXT-B2 cells did not express either MMP. In contrast, the mammary fat pad tumors expressed both gelatinases. Membrane Type 1-MMP transcripts were also detected in MXT cells and tumors. Because the mRNA levels of gelatinase. A were low in MXT-B2 tumors, we suggested that exogenous gelatinase A bound the cell membranes of MXT-B2 cells in vivo. Indirect evidence was obtained in vitro by treatment of MXT-B2 cells with NIH/3T3 fibroblast-conditioned medium. After this treatment, we detected a gelatinolytic activity at M(r) 68,000 in the cell-membrane extract of MXT-B2 cells and an increase in migratory ability through type IV collagen matrices. On the other hand, Ha-ras gene dosage correlated positively with metastatic ability but not with either gelatinase A or gelatinase B expression. No significant differences were observed in the expression of stromelysin-1 and tissue inhibitors of MMP. Thus, in the MXT tumor system, the expression of gelatinase A or its cell association and Ha-ras gene dosage independently contribute to the metastatic phenotype.
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PMID:Metastatic ability of MXT mouse mammary subpopulations correlates with clonal expression and/or membrane-association of gelatinase A. 918 Sep 29

Membrane vesicles are shed by tumor cells both in vivo and in vitro. Although their functions are not well understood, it has been proposed that they may play multiple roles in tumor progression. We characterized membrane vesicles from human HT1080 fibrosarcoma cell cultures for the presence of proteinases involved in tumor invasion. By gelatin zymography and Western blotting, these vesicles showed major bands corresponding to the zymogen and active forms of gelatinase B (MMP-9) and gelatinase A (MMP-2) and to the MMP-9. tissue inhibitor of metalloproteinase 1 complex. Both gelatinases appeared to be associated with the vesicle membrane. HT1080 cell vesicles also showed a strong, plasminogen-dependent fibrinolytic activity in 125I fibrin assays; this activity was associated with urokinase plasminogen activator, as shown by casein zymography and Western blotting. Urokinase was bound to its high affinity receptor on the vesicle membrane. Addition of plasminogen resulted in activation of the progelatinases associated with the vesicles, indicating a role of the urokinase-plasmin system in MMP-2 and MMP-9 activation. We propose that vesicles shed by tumor cells may provide a large membrane surface for the activation of membrane-associated proteinases involved in extracellular matrix degradation and tissue invasion.
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PMID:Urokinase plasminogen activator and gelatinases are associated with membrane vesicles shed by human HT1080 fibrosarcoma cells. 920 45

The expression of matrix metalloproteinase-2 (MMP-2; 72 kDa type IV collagenase/gelatinase A) and MMP-9 (92 kDa type IV collagenase/gelatinase B) was immunohistochemically investigated in 79 T1 adenocarcinomas of the lung using non-commercial polyclonal anti-MMP-2 and -9 antibodies. Thirty-two (41%) and 22 (28%) among the 79 cases were positive in the tumor cells for MMP-2 and -9, respectively. The incidences of MMP-2 and -9 immunoreactivities were higher (64 and 45%, respectively) in poorly differentiated tumors than in well differentiated tumors (36 and 25%, respectively), and lower in bronchioloalveolar carcinoma (22 and 10%, respectively) compared with other subtypes of adenocarcinoma. The prognosis for patients with MMP-2 and/or -9 positive immunoreactivities was significantly poorer than for those with a MMP-negative tumor (P < 0.05). The degree of collagenization was divided into four grades, and tumors with a small to abundant amount of collagen (grade 2 and grade 3 fibrosis) had a higher incidence of immunoreactivity to both types of MMP. It is estimated that these expressions might be responsible for tumor invasion, metastasis, and for grade 2 and grade 3 fibrosis in T1 adenocarcinoma of the lung.
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PMID:Expression of matrix metalloproteinase (gelatinase) in T1 adenocarcinoma of the lung. 923 85

Tumor cells exposed to a growth stress such as low pH, glucose starvation and hypoxia have been shown to exhibit a transient increase in experimental metastatic potential, particularly when allowed to recover under normal growth conditions for a period of 24-48 h. In this study we examined whether this increase in metastatic ability could be explained by changes in the expression of a number of different metastasis-associated genes, when the cells were exposed to similar conditions (24-48 h exposure to the stress condition followed by 0-48 h recovery under normal growth conditions). Although the cell lines used (KHT fibrosarcoma, SCC VII squamous cell carcinoma, and B16F1 melanoma) demonstrated altered metastatic ability after the treatment, no overall temporal correlation between changes in the mRNA levels for cathepsin B, cathepsin L, nm23, TIMP-1, osteopontin, or VEGF and metastatic ability in the three cell lines was observed. The production of gelatinase A (72 kDa collagenase) and gelatinase B (92 kDa collagenase) was also measured by gelatin zymography. There was an increase in production of these enzymes with increasing recovery time, but it did not parallel changes in metastatic potential. Although these results suggest that the products of most of the genes studied may not be involved in the transient metastatic changes, further studies are required to establish whether changes in protein levels track with changes in mRNA levels for these genes.
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PMID:An examination of the effects of hypoxia, acidosis, and glucose starvation on the expression of metastasis-associated genes in murine tumor cells. 924 50

By the degradative effect on basement membrane collagen type IV, matrix metalloproteinases (MMPs) or gelatinases are important in the early invasion of malignant tumors. These enzymes may be released by the tumor cells themselves or may be derived from nearby fibroblasts that have been stimulated by the extracellular MMP inducer EMMPRIN. We studied the distribution of 92-kd gelatinase B (MMP-9) and of EMMPRIN in 33 benign and 41 malignant, paraffin-embedded pigment cell lesions using immunohistochemistry and monoclonal antibodies. In benign pigment cell lesions, EMMPRIN but not gelatinase B was expressed in cellular blue nevi whereas all other benign lesions, including common blue nevi, were negative. In malignant melanomas (MMs), both gelatinase B and EMMPRIN were variably expressed in the pure and invasive radial growth phase but not in the vertical growth phase. All lentigo maligna cases and all metastatic lesions were negative. Of MMs with thickness < 1.6 mm, 63% expressed gelatinase B and 70% expressed EMMPRIN, whereas in MMs with > 1.6 mm thickness, only 10% expressed gelatinase B and only 25% expressed EMMPRIN. We conclude that early invasion of MM is associated with de novo expression of gelatinase B and EMMPRIN by neoplastic melanocytes. Expression of EMMPRIN and MMP-9 may be partly responsible for the stromal changes observed in thin MM. Their absence in the vertical growth phase and in metastatic lesions suggests that other factors are involved in tissue degradation during later stages of tumor progression in MM. The lack of both gelatinase B and EMMPRIN in lentigo maligna may contribute to the indolent behavior of this type of pigment cell lesion.
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PMID:Expression of gelatinase B and the extracellular matrix metalloproteinase inducer EMMPRIN in benign and malignant pigment cell lesions of the skin. 928 14

The malignant dissemination of tumors has been shown to require expression of one or more members of the matrix metalloprotease (MMP) enzyme family, whose function is to catalyze degradation of extracellular matrix proteins. In human squamous cell carcinoma (SCC) of the skin, expression of the MMP 92-kDa type IV collagenase (MMP-9), was previously shown to localize to malignant keratinocytes residing along the tumor/stromal interface. The purpose of the study presented here was to determine whether this localized expression pattern is due to interactions between SCC cells and adjacent stromal fibroblasts. To examine this question, SCC cells were grown as organotypic skin cultures, an in vitro three-dimensional model of reconstructed human epidermis in which keratinocytes are grown on a type 1 collagen gel embedded with human dermal fibroblasts. In this study, MMP-9 expression was compared in organotypic cultures (constructed with SCC cells or the non-tumorigenic keratinocyte cell line HaCaT), in which human dermal fibroblasts were either included or excluded from the underlying stromal layer. In the absence of fibroblasts, expression of MMP-9 was slightly higher in SCC than HaCaT cultures. In cultures constructed with fibroblasts, however, induction of MMP-9 mRNA was observed in SCC but not HaCaT cultures. This induction of MMP-9 mRNA was accompanied by high levels of MMP-9 protein expression along the SCC/stromal interface. These data provide strong evidence that interactions between malignant keratinocytes and adjacent stromal fibroblasts are critical in directing expression of MMP-9 to the tumor-stroma interface in human SCC tumors.
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PMID:Fibroblast-directed expression and localization of 92-kDa type IV collagenase along the tumor-stroma interface in an in vitro three-dimensional model of human squamous cell carcinoma. 929 Jul 3


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