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

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

Urokinase plasminogen activator (uPA) and metalloproteinases (MMP) play key roles in invasion and metastasis, degrading extracellular matrix compounds and modulating tumor cell motility. Their regulation is an attractive therapeutic target for controlling tumor metastasis. Previously we have demonstrated that urokinase overexpression in murine mammary tumor cells is regulated by a Ca2+-dependent pathway and that blockage of Ca2+ channels by verapamil partially inhibited their invasive and metastatic ability. Moreover, the catalytic inhibition of uPA by a synthetic uPA inhibitor B428 reduced local tumor invasiveness but not tumor cell dissemination. We evaluated the effect of a combined treatment with verapamil and B428 on the murine mammary carcinoma F3II behavior in vivo and in vitro. In vivo administration of the combined treatment was not associated to an overt toxicity. Only the daily combined treatment, beginning after tumor take, reduced the incidence and the number of spontaneous lung metastasis, while no differences were found in the subcutaneous growth of the primary tumor. Interestingly, a remarkable reduction in plasma MMP-9 activity was found associated to metastasis impairment. In addition, the number of experimental lung metastases was also significantly diminished, with respect to the control group, only when both compounds were co-administered daily, beginning three days after i.v. tumor cell injection. In vitro, both compounds, either separately or combined, could inhibit secreted uPA activity. F3II cell migration was significantly inhibited by incubation with 50 microM verapamil, 15 microM B428 or the co-treatment with 7.5 microM B428 + 25 microM verapamil. The cell spread was also significantly reduced when F3II cells were exposed to the compounds, with an additive effect when B428 + verapamil combination was used. The combination of two compounds acting through different molecular targets may be useful to improve the control of metastatic dissemination.
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PMID:Combined treatment with verapamil, a calcium channel blocker, and B428, a synthetic uPA inhibitor, impairs the metastatic ability of a murine mammary carcinoma. 1268 50

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

To enable individualized risk-oriented adjuvant treatment of breast cancer, validated parameters are needed to help evaluate the individual relapse risk. The clinical significance of these factors is assessed by published evidence (level of evidence) and its utility in the clinical setting (utility score). The traditional prognostic factors (age, TNM stage, grading, and steroid hormone receptor status are of established clinical relevance, and their determination should be obligatory. Of the "new" tumor-biologic parameters, only the measurement of the urokinase-type plasminogen activator (uPA) and its inhibitor (PAI-1) in the primary tumor of node-negative patients has been adequately validated and can therefore be recommended for clinical application. Promising recent prognostic markers are the expression of Her2/neu, detection of disseminated tumor cells in bone marrow aspirates, various different surrogates for proliferative activity, and tumor-specific gene expression profiles. Currently, however, the data available are insufficient to allow recommendation of the parameters for routine clinical use at this time.
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PMID:[Prognostic factors in carcinoma of the breast. Thereupon depends success of the treatment]. 1286 97

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

Urokinase-type plasminogen activator (uPA) and its inhibitor, PAI-I, play a key role in tumor invasion and metastasis. They were the first novel tumor biological factors to be validated at the highest level of evidence (LOE I) regarding their clinical utility in breast cancer. Their antigen levels are determined in tumor tissue extracts by standardized, quality-assured immunometric assays (ELISA). Since the late 1980s, numerous independent studies have demonstrated that patients with low levels of uPA and PAI-I in their primary tumor tissue have a significantly better survival than patients with high levels of either factor. These prognostic data have recently been validated by an EORTC (European Organization for Research and Treatment of Cancer) pooled analysis comprising more than 8,000 breast cancer patients. In addition, results from a multicenter prospective randomized therapy trial in node-negative breast cancer ("Chemo N(0)") showed that node-negative breast cancer patients with low levels of uPA and PAI-I in their primary tumor have a very good prognosis, and may thus be candidates for being spared the burden of adjuvant chemotherapy. In contrast, node-negative patients with high uPA/PAI-I are at substantially increased risk of disease recurrence, comparable to that of patients with three or more tumor cell positive axillary lymph nodes. The "Chemo N(0)" trial as well as retrospective data also indicate that these high-risk patients benefit from adjuvant chemotherapy. In conclusion, over a period of about 15 years sufficient evidence has been put forward to demonstrate that determination of uPA and PAI-I in primary breast cancer patients supports risk-adapted individualized therapy decisions, particularily in patients with node-negative disease.
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PMID:Urokinase-type plasminogen activator (uPA) and its inhibitor PAI-I: novel tumor-derived factors with a high prognostic and predictive impact in breast cancer. 1498 19

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

Disseminated tumor cells (DTC) in bone marrow are independently related to poor outcome in patients with breast cancer. Phenotypic characterization of DTC may be useful to improve evaluation of the metastasizing potential of DTC and also to more accurately target aggressive tumor cells. DTC were screened in bone marrow aspirates from breast cancer patients by immunocytochemistry with an anticytokeratin (anti-CK) antibody (A45B/B3). Because the cell permeabilization and fixation required for intracellular CK staining is deleterious for mRNA, we used microaspiration to isolate single tumor cells stained with a monoclonal antibody directed against a membrane epitope, epithelial cell adhesion molecule (EpCAM), in CK-positive cases. Urokinase-type plasminogen activator receptor (uPAR) was quantified by real-time quantitative RT-PCR. The SKBR3 human breast cancer cell line was used to calibrate RT-PCR. A linear relationship was observed between the cycle threshold (Ct) of uPAR and 18S gene expression and SKBR3 cells spiked (1, 3, 7, 10 and 20) in control patient bone marrow. EpCAM-positive cells were aspirated in 21 out of 25 bone marrow specimens from breast cancer patients with CK-positive cells and uPAR mRNA expression was determined in 16 cases. A high level of uPAR mRNA in DTC was detected in 8 out of 16 patients (50%) and was associated with a more aggressive primary tumor phenotype (estrogen receptor [ER]-negative, progesterone receptor [PR]-negative or HER2-positive) (p = 0.01). We demonstrated that real-time quantitative RT-PCR was reliably adapted to phenotype analysis of isolated micrometastatic cells. A larger study would be useful to confirm the importance of uPAR to define higher risk subgroups of breast cancer patients with micrometastatic disease.
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PMID:Real-time quantitative PCR determination of urokinase-type plasminogen activator receptor (uPAR) expression of isolated micrometastatic cells from bone marrow of breast cancer patients. 1554 15

Combined determination of urokinase-type plasminogen activator (uPA) and its inhibitor, activator inhibitor type 1 (PAI-1), supports risk-adapted individualized therapy concepts, particularly in node-negative breast cancer. The prognostic impact of both factors in primary breast cancer was substantiated by a pooled analysis of > 8000 patients with breast cancer and a multicenter prospective randomized therapy trial in node-negative breast cancer; findings achieved the highest level of evidence for tumor biomarkers. Patients with node-negative breast cancer with low antigen levels of uPA and PAI-1 in their primary tumor tissue have a very good prognosis and therefore may be spared the burden of adjuvant chemotherapy, whereas those with elevated uPA/PAI-1 antigen levels carry an increased risk of disease recurrence. Recent retrospective analysis of > 3000 patients indicated that patients with breast cancer with high uPA/PAI-1 values derive a significantly greater benefit from adjuvant chemotherapy than patients with low uPA/PAI-1 levels. Similarly, in the multicenter prospective Chemo N0 trial, administration of cyclophosphamide/methotrexate/5-fluorouracil-based chemotherapy led to a substantial reduction in risk of disease recurrence in patients with high uPA/PAI-1. However, benefit from adjuvant endocrine therapy appears to be independent of a patient's uPA/PAI-1 status. In metastatic breast cancer, retrospective studies showed that elevated uPA or PAI-1 present in the primary tumor tissue are associated with a poor response to later palliative endocrine therapy. These findings suggest that high levels of uPA and/or PAI-1 do reflect an aggressive phenotype that may be overcome or suppressed by early systemic therapy in the adjuvant setting but may be too advanced for response to palliative therapy at a later stage.
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PMID:Urokinase-type plasminogen activator and its inhibitor type 1 predict disease outcome and therapy response in primary breast cancer. 1558 71


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