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: UMLS:C0677930 (primary tumor)
20,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The serine protease urokinase-type plasminogen activator, uPA, when bound to its specific receptor, uPAR (CD87), plays a significant role in tumor cell invasion and metastasis. In breast cancer, enhanced uPA antigen in the primary tumor is correlated with poor prognosis of the patient. In an in vivo nude mouse model, we tested tumor growth and metastasis of human breast carcinoma cells that had been transfected with an expression plasmid encoding a soluble form of uPAR (suPAR). We explored, whether suPAR/uPA interaction reduces the binding of uPA to cell surface-associated uPAR, and, as a consequence, could suppress tumor growth and metastasis of the human breast cancer cell line MDA-MB-231 BAG. Overexpressed, secreted suPAR was shown to bind and thus scavenge the uPA secreted by the transfected lines suPAR3 and suPAR10. In vitro, an overexpression of suPAR did not alter the proliferation rate of the transfected tumor cells, nor did it affect the expression of uPA. Overexpression of suPAR led to a reduction in the plasminogen activation-related proteolytic activity of breast carcinoma cells. Primary tumor growth in the mammary fat pad of nude mice was followed up for 52 days. Overexpression of suPAR correlated with a reduction in tumor growth (from day 21, reaching 30% by day 34) as well as lung colonization (lung metastasis-positive mice in suPAR3: 4 of 17; suPAR10: 3 of 10; parental MDA-MB-231 BAG: 13 of 18). We conclude that suPAR overexpression leading to effective scavenge of uPA impairs proteolysis as well as the tumor growth and metastatic potential of breast carcinoma cells in vivo.
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PMID:Reduction of breast carcinoma tumor growth and lung colonization by overexpression of the soluble urokinase-type plasminogen activator receptor (CD87). 1077 Jun 39

Invasion and dissemination of well-differentiated carcinomas are often associated with loss of epithelial differentiation and gain of mesenchymal-like capabilities of dedifferentiated tumor cells at the invasive front. However when analysing central areas of metastases of colorectal carcinomas one finds a regain of the differentiated epithelial growth patterns like in the primary tumor. More than 80% of these tumor have loss of function mutations in the APC tumor suppressor gene, leading to an overexpression of beta-catenine. In its nuclear pool beta-catenine acts as a transcription factor and is now considered as one of the main oncogenic proteins in colorectal carcinogenesis. We could define several molecules important for the processes of invasion and dissemination, like MMP-7, uPA, laminin-5, as target genes activated by nuclear beta-catenine. Moreover the characteristic phenotypic changes during tumor progression were associated with distinct expression patterns of beta-catenine and E-cadherin. Nuclear beta-catenine was found in dedifferentiated mesenchyme-like tumor cells at the invasive front, but strikingly, like in central areas of the primary tumors, was localized to the membrane and cytoplasm in polarized epithelial tumor cells in the metastases. This was accompanied by changes in the proliferative activity. Based on these data, we postulate that an important driving force for progression of well-differentiated colorectal carcinomas is the specific environment, initiating two transient phenotypic transition processes by modulating intracellular beta-catenine distribution in the tumor cells.
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PMID:[The Rudolf Virchow Prize 2001. The role of the oncoprotein beta-catenin ni the progression of colorectal cancers]. 1189 5

Cutaneous melanoma is an invasive and early metastazising tumor. Melanoma cells detach from the primary tumor, penetrate the basement membrane, invade lymphatics and blood vessels, and form metastases. These processes all depend on coordinated expression and/or activation of proteolytic enzymes. In addition to aspartyl- and cysteineproteinases, serine proteinases including the plasminogen activator system (uPA, uPAR, tPA, PAI-1 and PAI-2) and matrix metalloproteinases (MMPs) with their tissue inhibitors (TIMPs) play an essential role in these processes. In addition, melanoma cells require specific adhesion molecules such as integrins and CD44 for interaction with other cells and components of the extracellular matrix (ECM); these are also involved in binding activated MMPs on the cell surface. In this review we discuss these functional aspects of melanoma progression.
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PMID:[Role of matrix-degrading enzymes in melanoma progression]. 1220 62

After dissemination from a primary tumor, cancer cells may resume growth, leading to overt metastasis, or enter a state of protracted dormancy. However, mechanisms that determine their fate, or markers that predict it, are mostly unavailable. We previously showed that in HEp3 human head and neck carcinoma, the extracellular signal-regulated kinase (ERK)(MAPK)/p38(SAPK) activity ratio predicts whether the cells will proliferate or enter a state of dormancy in vivo. The proliferative balance of high ERK/p38 ratio was induced by high urokinase (uPA) receptor (uPAR) expression, which activated alpha5beta1-integrin and epidermal growth factor receptor. This signaling pathway was additionally enhanced by uPA binding to uPAR and fibronectin binding to alpha5beta1-integrin. We tested whether the ERK/p38 balance is predictive of in vivo behavior in other cancer cell types and whether altering the balance will shift their phenotype between proliferation and dormancy. ERK and p38 activities were determined using either phospho-specific monoclonal antibodies or a trans-reporting system where GAL4-Elk and GAL4-CHOP trans-activation of luciferase gene served as reporters for ERK and p38 activities, respectively. We show that in breast, prostate, melanoma, and fibrosarcoma cell lines, the level of active phospho-ERK and the ERK/p38 activity ratio predict for the in vivo behavior in approximately 90% of the cell lines tested. Modulation of ERK/p38 activity ratio by multiple pharmacological and genetic interventions confirms that high ERK/p38 ratio favors tumor growth, whereas high p38/ERK ratio induces tumor growth arrest (dormancy) in vivo and that ERK is negatively regulated by p38. A melanoma cell line appeared to have developed an escape mechanism to avoid the growth inhibitory effect of high p38 activity. Mechanistic analysis implicated high uPAR expression and its interaction with and activation of alpha5beta1-integrin as determinants of the in vivo growth promoting high ERK/p38 ratio in several cell lines. The small GTPase, Cdc42, was implicated in activation of p38 and growth arrest. These results suggest that even cells that originate in advanced cancers retain a degree of dependence on surface receptors and matrix for their proliferative signals in vivo and provide a therapeutic opportunity to change their phenotype from tumorigenic to dormant.
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PMID:ERK(MAPK) activity as a determinant of tumor growth and dormancy; regulation by p38(SAPK). 1267 Sep 23

In breast cancer, about 35% of patients without any clinical signs of overt distant metastases already have disseminated tumor cells in bone marrow aspirates at the time of primary therapy. A significant prognostic impact of these disseminated tumor cells has been shown by many international studies: patients with tumor cells in their bone marrow have a significantly worse prognosis than those without them. Even in malignancies where the skeletal system is not a preferred location for distant metastasis, such as ovarian cancer, early presence of minimal residual disease (MRD) is correlated with poor patient outcome. Thus, besides analysis of the primary tumor, detection of MRD can be used for assessment of patient prognosis and for prediction or monitoring of response to systemic therapy. Disseminated tumor cells are also the targets for novel tumor biological therapy approaches such as specific antibody-based therapies against target cell-surface antigens such as HER2, Ep-CAM (17-1A), and uPA-R. In breast cancer, a first antibody-based tumor therapy against HER2 (Herceptin) has already been approved for clinical use in recurrent disease. However, patient selection for such tumor biological therapies becomes rather difficult due to phenotype changes, which may manifest themselves as differences between primary lesion and disseminated tumor cells. Therefore, not only identification of disseminated tumor cells but even more so their characterization at the protein and gene levels have become increasingly important. In conclusion, characterization of tumor biological properties of disseminated tumor cells allows identification of patients with breast cancer or gynecological malignancies at risk for relapse who are likely to benefit from systemic treatment and/or novel tumor biological therapy approaches.
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PMID:Minimal residual disease in breast cancer and gynecological malignancies: phenotype and clinical relevance. 1279 Mar 24

The plasminogen activator inhibitor-1 (PAI-1) blocks the activation of plasmin(ogen), an extracellular protease vital to cancer invasion. PAI-1 is like the corresponding plasminogen activator uPA (urokinase-type plasminogen activator) consistently expressed in human breast cancer. Paradoxically, high levels of PAI-1 as well as uPA are equally associated with poor prognosis in cancer patients. PAI-1 is thought to play a vital role for the controlled extracellular proteolysis during tumor neovascularization. We have studied the effect of PAI-1 deficiency in a transgenic mouse model of metastasizing breast cancer. In these tumors, the expression pattern of uPA and PAI-1 resembles that of human ductal breast cancer and plasminogen is required for efficient metastasis. In a cohort of 63 transgenic mice that were either PAI-1-deficient or wild-type sibling controls, primary tumor growth and vascular density were unaffected by PAI-1 status. PAI-1 deficiency also did not significantly affect the lung metastatic burden. These results agree with the virtual lack of spontaneous phenotype in PAI-1-deficient mice and humans and may reflect that the plasminogen activation reaction is not rate limiting for tumor vascularization and metastasis, or that there is a functional redundancy between PAI-1 and other inhibitors of the uPA/plasmin system, masking the effect of PAI-1 deficiency.
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PMID:Metastasis of transgenic breast cancer in plasminogen activator inhibitor-1 gene-deficient mice. 1285 75

uPA and PAI-1 are the first novel tumor biological prognostic factors in breast cancer for which the prognostic impact has been validated at the highest level of evidence and hence all evaluation criteria for transfer into clinical practice have been fullfilled. Breast cancer patients with high uPA and/or PAI-1 levels in their primary tumor tissue have a significantly lower chance for cure than patients with low levels of both uPA and PAI-1. Our research that was honored with the Schmidt-Matthiesen-Award 2002 shows for the first time that uPA and PAI-1 are not only prognostic factors but also have a predictive impact with regard to response to adjuvant chemotherapy. Patients with high uPA/PAI-1 derive a significantly greater benefit from adjuvant chemotherapy than patients with low uPA/PAI-1. Benefit from adjuvant endocrine therapy is independent of uPA/PAI-1 status. The resulting question about the optimal chemotherapy for patients with high uPA/PAI-1 is currently being addressed in Germany by the NNBC-3 trial in node-negative breast cancer (AGO, EORTC-RBG) as well as the ADEBAR trial in patients with 4 or more involved axillary lymph nodes. Moreover, our results suggest the use of novel therapeutic agents interfering with the uPA system together with conventional chemotherapy in patients with high uPA/PAI-1 already in early stage disease.
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PMID:[u-Plasminogen activator (urinary plasminogen activator, urokinase) (uPA) and its PA-1 type 1 inhibitor are not only prognostically but also predictively significant and support clinical decisions on therapy in primary carcinoma of the breast]. 1456 18

A prominent phenotype of plasmin deficiency in mice is reduced metastasis in the MMTV-PymT transgenic breast cancer model. Proteolytically active plasmin is generated from inactive plasminogen by one of 2 activators, uPA or tPA. We now find that uPA deficiency alone significantly reduces metastasis >7-fold in the MMTV-PymT model. We studied a cohort of 55 MMTV-PymT transgenic mice, either uPA-deficient or wild-type controls. Tumor incidence, latency, growth rate and final primary tumor burden were not significantly affected by uPA deficiency. In contrast, average lung metastasis volume was reduced from 1.58 mm(3) in wild-type controls to 0.21 mm(3) in uPA-deficient mice (p = 0.023). Tumor cell dissemination to brachial lymph nodes was also reduced from 53% (28/53) in wild-type controls to 31% (17/54) in uPA-deficient mice (p = 0.032). Mice without plasminogen display a severe pleiotropic phenotype. By comparison, spontaneous phenotypes are modest in uPA-deficient mice, probably because they still have active tPA. We show that metastasis is strongly and selectively decreased in uPA-deficient mice, suggesting that uPA-directed antimetastatic therapy would be efficacious and have limited side effects.
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PMID:Reduced metastasis of transgenic mammary cancer in urokinase-deficient mice. 1547 5

In epithelial ovarian cancer, the high mortality rate is usually ascribed to late diagnosis, since these tumors commonly lack early-warning symptoms, but tumor-associated biomarkers useful for prognosis or therapy response prediction are in short supply. However, members of the tissue kallikrein serine protease family, the serine protease uPA and its inhibitor PAI-1, are associated with tumor progression of ovarian cancer. Therefore, we used ELISA to determine uPA, PAI-1, and tissue kallikreins hK5-8, 10, 11, and 13 in extracts of 142 primary tumor tissue specimens from ovarian cancer patients and studied the strength of association between protein expression levels of these tumor tissue-associated factors. uPA, PAI-1, hk5, and hk8 were related to FIGO stage; hK5 expression was higher in FIGO III/IV than in FIGO I/II patient tissues. PAI-1 and hk5 differed significantly according to nuclear grading; expression of hK5 was higher in G3 than in G1/2 tumors. Associations between uPA, PAI-1, and the tissue kallikreins were weak. There were strong pairwise correlations within the cluster of tissue kallikreins hK5, 6, 7, 8, 10, and 11, but their bivariate distributions depended on nuclear grading. These results support the notion that several tissue kallikreins are co-expressed in ovarian cancer patients, substantiating the existence of a steroid hormone-driven tissue kallikrein cascade in this disease.
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PMID:Disease processes may be reflected by correlations among tissue kallikrein proteases but not with proteolytic factors uPA and PAI-1 in primary ovarian carcinoma. 1689 83

The plasminogen activator system is a complex system with multiple interactions and members participating in fibrinolysis, cell migration, angiogenesis, wound healing, embryogenesis, tumor cell dissemination, and metastasis in a variety of solid tumors. Increased levels of uPA and/or PAI-1 in primary tumor tissues of breast cancer patients correlate with tumor aggressiveness and poor clinical outcome. Patients with high tumor tissue antigen content of uPA and/or PAI-1 have a worse probability of disease-free and overall survival than patients with low levels of both of the biomarkers, serving as prognostic markers. The clinical utility of uPA and PAI-1 has been proven on the highest level of evidence (LOE-I). Next to being clinically useful prognostic factors allowing estimates of the course of disease in early breast cancer, uPA and PAI-1 may also serve as predictive factors predicting response to systemic therapy. Node-negative primary breast cancer patients with high uPA/PAI-1 levels benefit significantly from adjuvant chemotherapy. The aim of the ongoing NNBC-3 trial is to determine the benefits of a sequential anthracycline-docetaxel regimen in high-risk node-negative breast cancer patients compared to the current standard of anthracycline-based chemotherapy. At present, uPA and PAI-1 provide the unique opportunity to allow validated and clinically relevant risk assessment of breast cancer patients, over and above that provided by established risk factors. Therefore, in the evidence-based, annually updated AGO guidelines for breast cancer management, the German Working Group for Gynecological Oncology (AGO) has recommended both biomarkers as risk-group-classification markers for routine clinical decision making in node-negative breast cancer, next to established clinical and histomorphological factors.
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PMID:uPA and PAI-1 in breast cancer: review of their clinical utility and current validation in the prospective NNBC-3 trial. 1842 92


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