The content of urokinase-type plasminogen activator antigen as a prognostic factor in urinary bladder cancer

Aidi injection inhibits the migration and invasion of gefitinib-resistant lung adenocarcinoma cells by regulating the PLAT/FAK/AKT pathway

BACKGROUND

With extended gefitinib treatment, the therapeutic effect in some non-small cell lung cancer (NSCLC) patients declined with the development of drug resistance. Aidi injection (ADI) is utilized in various cancers as a traditional Chinese medicine prescription. This study explores the molecular mechanism by which ADI, when combined with gefitinib, attenuates gefitinib resistance in PC9GR NSCLC cells.

METHODS

In vitro and in vivo pharmacological experiments were conducted in PC9GR cells and NSG mice with PC9GR cell-derived tumors, respectively. The molecular mechanism of ADI was further studied using whole-transcriptome sequencing technology. Bioinformatics and molecular biology methods were employed to validate the critical targets of ADI.

RESULTS

Firstly, ADI treatment alone and combined with gefitinib significantly inhibited the proliferation, migration, and invasion of PC9GR cells. Then, whole-transcriptome sequencing and bioinformatics analysis revealed that PLAT is a key target for the increased efficacy of ADI combined with gefitinib. Additionally, ADI downregulates the expression of PLAT, TNC, ITGB3, p-AKT, p-PI3K, and p-FAK. ADI inhibits the migration and invasion of PC9GR cells by regulating the PLAT/FAK/AKT pathway.

CONCLUSIONS

Aidi injection inhibits the migration and invasion of gefitinib-resistant lung adenocarcinoma cells by regulating the PLAT/FAK/AKT pathway. This study provides essential evidence for elucidating the mechanism of ADI in synergistic therapy for lung cancer.

Further Understanding of Urokinase Plasminogen Activator Overexpression in Urothelial Bladder Cancer Progression, Clinical Outcomes and Potential Therapeutic Targets

Purpose

The Plasminogen Activation System (PAS) plays a role in tumor growth, invasion and metastasis and has been associated with oncological outcomes in urinary bladder carcinoma (UBC). The use of the different components of this system as molecular markers could improve our understanding of the heterogeneous behavior of UBC and might enable earlier disease detection, individual risk stratification, more accurate outcome prediction and be a rationale for new targeted therapies.

Methods

A comprehensive literature search including relevant articles up to October 2020 was performed using the MEDLINE/PubMed database.

Results

The components of the PAS axis are involved in tumor progression through their signaling processes during angiogenesis, cell migration, metastasis and adhesion. The body of evidence shows an association of PAS component overexpression with adverse pathological features and clinical outcome in UBC. Overexpressed PAS components correlate with a higher pathological tumor grade and advanced tumor stage. In non-muscle-invasive bladder cancer (NMIBC), the PAS components were associated with disease outcome while in muscle-invasive bladder cancer (MIBC), it was associated with disease outcome and pathological features. Possible therapeutic approaches in the PAS for the treatment of UBC have only been sparsely investigated in in vitro and in vivo studies. Intravesical plasminogen activator inhibitor 1 (PAI-1) instillation in animal models yielded interesting results and warrant further exploration in Phase II studies.

Conclusion

The overexpression of PAS components in UBC tumor tissue is associated with adverse pathological features and worse oncological outcomes. These findings are mainly based on preclinical studies and retrospective series, which requires further prospective studies to translate the PAS into clinically useful biomarkers and therapeutic targets.

The prognostic value of the urokinase-plasminogen activator system (uPA) in bladder cancer patients treated with radical cystectomy (RC)

PURPOSE

Urokinase-plasminogen activator (uPA), its receptor (uPAR), and the plasmin-activator inhibitor type 1 (PAI-1) have been associated with oncologic outcomes in various malignancies and could help identify bladder cancer (BC) patients treated with radical cystectomy (RC) who are likely to benefit from intensification of therapy to prevent disease progression. Our aim was to assess the value of uPA, uPAR, and PAI-1 for prognosticating survival outcomes of patients treated with RC for BC.

MATERIALS AND METHODS

Tumor specimens from 272 consecutive patients treated with RC for advanced BC were assessed with immunohistochemical staining for uPA, uPAR, and PAI-1. Overexpression was assessed by pathological image analysis. Kaplan-Meier estimates and multivariable Cox-regression were used to analyze survival. Harrell's C-index was used to assess for clinical impact of the uPA system.

RESULTS

uPA, uPAR, and PAI-1 were overexpressed in 48.2%, 51.1%, and 52.2% of patients, respectively. uPA overexpression was associated with lymphovascular invasion (P = 0.034) and nodal status (P = 0.013); PAI-1 overexpression was associated with primary muscle-invasive BC (P = 0.015) and lymphovascular invasion (P = 0.024). uPA, uPAR, and the number of overexpressed markers were all 3 significantly associated with shorter overall recurrence-free-, distant recurrence-free-, and cancer-specific survival. In multivariable analyses, uPA overexpression remained associated with shorter recurrence-free survival (hazard ratio [HR] = 1.79; P = 0.036) in the entire cohort, in patients without lymph node metastasis (HR = 1.98; P = 0.018) and those with nonorgan-confined disease (HR = 1.98; P = 0.022). uPAR overexpression was associated with shorter recurrence-free survival in patients without lymph node metastasis (HR = 2.01; P = 0.021) and those with organ-confined disease (HR = 4.11; P = 0.037).

CONCLUSION

Members of the uPA system are associated with features of biologically aggressive BC and oncologic outcomes. However, their value beyond currently available information remains limited.

Tazarotene-Induced Gene 1 (TIG1) Interacts with Serine Protease Inhibitor Kazal-Type 2 (SPINK2) to Inhibit Cellular Invasion of Testicular Carcinoma Cells

Tazarotene-induced gene 1 (TIG1) encodes a protein that is a retinoid-regulated tumor suppressor. TIG1 is expressed in most normal tissues, and downregulation of TIG1 expression in multiple cancers is caused by promoter hypermethylation. Kazal-type serine protease inhibitor-2 (SPINK2) is a serine protease inhibitor, and the SPINK protein family has been shown to inhibit the expression of urokinase-type plasminogen activator (uPA). In addition, increased levels of uPA and the uPA receptor were observed in testicular cancer tissues. This study demonstrated that TIG1 interacts with SPINK2 in NT2/D1 testicular carcinoma cells. TIG1 and SPINK2 were highly expressed in normal testis tissues, while low expression levels of TIG1 and SPINK2 were found in testicular cancer tissues. TIG1 inhibited cell invasion, migration, and epithelial-mesenchymal transition (EMT) of NT2/D1 cells. SPINK2 enhanced TIG1-regulated uPA activity and EMT suppression, while silencing SPINK2 alleviated TIG1-mediated EMT regulation, cell migration, and invasion. Therefore, the results suggest that the interaction between TIG1 and SPINK2 plays an important role in the inhibition of testicular cancer cell EMT, and suppression is mediated through downregulation of the uPA/uPAR signaling pathway.

Tissue-Type Plasminogen Activator (tPA) Content in Colorectal Cancer and in Surrounding Mucosa: Relationship with Clinicopathologic Parameters and Prognostic Significance

The aim of this study was to evaluate the cytosolic tissue-type plasminogen activator (tPA) content in colorectal cancer, its possible relationship with the clinicopathologic parameters of tumors, and its prognostic significance. We have therefore examined by immunoenzymatic assay the cytosolic tPA content in tumors and paired surrounding normal mucosa samples from 162 colorectal cancer patients. Cytosolic tPA levels were significantly higher in surrounding normal mucosa samples than in neoplastic tissues (4.01±5.07 vs 2.63±5.82 ng/mg protein; p<0.0001). By contrast, no significant correlation was found between tPA content and clinicopathologic tumor parameters such as location, Dukes’ stage, histologic grade, and DNA content or S-phase fraction. However, the results indicated that a high cytosolic tPA content (>0.75 ng/mg protein) in tumors predicted for a shorter relapse-free and overall survival (both p<0.05) in 123 resectable colorectal cancer patients who were prospectively evaluated during a mean follow-up period of 32.2 months. This suggests that tPA may give additional information to that provided by other biochemical markers currently used in colorectal cancer.

Involvement of urokinase-type plasminogen activator system in cancer: an overview

Currently, there are several studies supporting the role of urokinase-type plasminogen activator (uPA) system in cancer. The association of uPA to its receptor triggers the conversion of plasminogen into plasmin. This process is regulated by the uPA inhibitors (PAI-1 and PAI-2). Plasmin promotes degradation of basement membrane and extracellular matrix (ECM) components as well as activation of ECM latent matrix metalloproteases. Degradation and remodeling of the surrounding tissues is crucial in the early steps of tumor progression by facilitating expansion of the tumor mass, release of tumor growth factors, activation of cytokines as well as induction of tumor cell proliferation, migration, and invasion. Hence, many tumors showed a correlation between uPA system component levels and tumor aggressiveness and survival. Therefore, this review summarizes the structure of the uPA system, its contribution to cancer progression, and the clinical relevance of uPA family members in cancer diagnosis. In addition, the review evaluates the significance of uPA system in the development of cancer-targeted therapies.

Bladder carcinoma: understanding advanced and metastatic disease with potential molecular therapeutic targets

This article is an expert review of bladder cancer genetics focusing on genetic changes and their significance in the pathogenesis and progression of bladder transitional cell carcinoma, in particular, muscle-invasive disease. Alongside the relevant genetic markers and their products, new therapeutic targets and agents that are being developed are presented.

Identification of potential bladder cancer markers in urine by abundant-protein depletion coupled with quantitative proteomics

In this study, we evaluated the reproducibility of abundant urine protein depletion by hexapeptide-based library beads and an antibody-based affinity column using the iTRAQ technique. The antibody-based affinity-depletion approach, which proved superior, was then applied in conjunction with iTRAQ to discover proteins that were differentially expressed between pooled urine samples from hernia and bladder cancer patients. Several proteins, including seven apolipoproteins, TIM, SAA4, and proEGF were further verified in 111 to 203 individual urine samples from patients with hernia, bladder cancer, or kidney cancer. Six apolipoproteins (APOA1, APOA2, APOB, APOC2, APOC3, and APOE) were able to differentiate bladder cancer from hernia. SAA4 was significantly increased in bladder cancer subgroups, whereas ProEGF was significantly decreased in bladder cancer subgroups. Additionally, the combination of SAA4 and ProEGF exhibited higher diagnostic capacity (AUC=0.80 and p<0.001) in discriminating bladder cancer from hernia than either marker alone. Using MetaCore software to interpret global changes of the urine proteome caused by bladder cancer, we found that the most notable alterations were in immune-response/alternative complement and blood-coagulation pathways. This study confirmed the clinical significance of the urine proteome in the development of non-invasive biomarkers for the detection of bladder cancer.

BIOLOGICAL SIGNIFICANCE

In this study, we evaluated the reproducibility of abundant urine protein depletion by hexapeptide-based library beads and an antibody-based affinity column using the iTRAQ technique. The antibody-based affinity-depletion approach, which proved superior, was then applied in conjunction with iTRAQ to discover proteins that were differentially expressed between pooled urine samples from hernia and bladder cancer patients. Several proteins, including seven apolipoproteins, TIM, SAA4, and proEGF were further verified in 111 to 203 individual urine samples from patients with hernia, bladder cancer, or kidney cancer. SAA4 was significantly increased in bladder cancer subgroups, whereas ProEGF was significantly decreased in bladder cancer subgroups. Additionally, the combination of SAA4 and ProEGF exhibited higher diagnostic capacity in discriminating bladder cancer from hernia than either marker alone. A marker panel composed by two novel biomarker candidates, SAA4 and proEGF, was first discovered and verified successfully using Western blotting. To the best of our knowledge, the associations of urinary SAA4 and proEGF with bladder tumor and kidney cancer have not been mentioned before. In the present study, we discovered and verified SAA4 and proEGF as potential bladder cancer biomarker for the first time.

Expression of urokinase-type plasminogen activator (uPA), its receptor (uPAR), and inhibitor (PAI-1) in human breast carcinomas and their clinical relevance

Serine proteases convert plasminogen to plasmin which is involved in tissue remodeling under physiologic and pathophysiologic conditions, including breast carcinoma invasion and progression. Both urokinase-type plasminogen activator (uPA) and pro-uPA associate with uPA receptor (uPAR) on target cells, where plasminogen activator inhibitors (e.g., PAI-1) may modulate their activities. Expression levels of these factors were compared in breast carcinomas relative to patient characteristics, carcinoma features, and clinical outcome. uPA, uPAR, and PAI-1 were quantified by enzyme-linked immunosorbent assay (ELISA) in extracts of 226 biopsies while estrogen receptor (ER) and progestin receptor (PR) were determined by enzyme immunoassay (EIA) or radio-ligand binding. Each set of assays contained a novel reference specimen with known quantities of each of these five analytes. Levels in ng/mg protein of these biomarkers exhibited ranges: uPA (0-12.3); uPAR (0-19.5); PAI-1 (0-91.2). When considered independently, expression of uPA, uPAR, or PAI-1 was unrelated to patient age or menopausal status. Although no correlation was observed between each analyte with stage, grade, or ER/PR status, levels appeared to differ with pathology and nodal status. A dendrogram from hierarchical clustering of uPA, uPAR, and PAI-1 levels in 106 specimens revealed three clusters of breast cancer patients. Kaplan-Meier analyses of uPA, uPAR, and PAI-1 indicated a correlation with overall survival (OS), suggesting collective examination of these biomarkers is useful in predicting clinical outcome of breast cancer.

Humoral innate immune response and disease

The humoral innate immune response consists of multiple components, including the naturally occurring antibodies (NAb), pentraxins and the complement and contact cascades. As soluble, plasma components, these innate proteins provide key elements in the prevention and control of disease. However, pathogens and cells with altered self proteins utilize multiple humoral components to evade destruction and promote pathogy. Many studies have examined the relationship between humoral immunity and autoimmune disorders. This review focuses on the interactions between the humoral components and their role in promoting the pathogenesis of bacterial and viral infections and chronic diseases such as atherosclerosis and cancer. Understanding the beneficial and detrimental aspects of the individual components and the interactions between proteins which regulate the innate and adaptive response will provide therapeutic targets for subsequent studies.

Activation of urokinase plasminogen activator and its receptor axis is essential for macrophage infiltration in a prostate cancer mouse model

Macrophages within the tumor microenvironment promote angiogenesis, extracellular matrix breakdown, and tumor cell migration, invasion, and metastasis. Activation of the urokinase plasminogen activator (uPA) and its receptor (uPAR) axis promotes prostate cancer tumorigenicity, invasion, metastasis, and survival within the tumor microenvironment. The link between macrophage infiltration and the uPA/uPAR axis in prostate cancer development has not been established, although it has been reported that uPA plays a critical role inmonocyte and macrophage chemotaxis. In this study, murine prostate cancer RM-1 cells were subcutaneously inoculated into wild-type (WT), uPA(-/-), and uPAR(-/-) mice. Tumor volume was significantly diminished in both uPA(-/-) and uPAR(-/-) mice compared with WT controls. Greater inhibition of tumor volume was also observed in uPA(-/-) mice compared with uPAR(-/-) mice, suggesting the important contribution of stromal-derived uPA to sustain the tumor growth. Immunohistochemical staining revealed that tumors in uPA(-/-) and uPAR(-/-) mice displayed significantly lower proliferative indices, higher apoptotic indices, and less neovascularity compared with the tumors in WT mice. Tumors in uPA(-/-) and uPAR(-/-) mice displayed significantly less macrophage infiltration as demonstrated by F4/80 staining and MAC3(+) cell numbers by flow cytometry compared with the tumors from WT mice. These findings suggest that the uPA/uPAR axis acts in both autocrine and paracrine manners in the tumor microenvironment, and activation of uPA/uPAR axis is essential for macrophage infiltration into prostate tumors.

NFkappaB-dependent regulation of urokinase plasminogen activator by proanthocyanidin-rich grape seed extract: effect on invasion by prostate cancer cells

Tumor invasion and metastasis present major obstacles to successful control of androgen-independent prostate cancer. Cell migration is a fundamental aspect of cancer cell metastasis. Urokinase plasminogen activator (uPA) system is implicated in cell migration and cancer metastasis and has potential to be developed as therapeutic target. In recent years, efficacy of dietary nutrients in preventing and curing cancer has gained increasing attention. One such promising candidate is proanthocyanidin-rich grape seed extract (GSE). We investigated the efficacy of GSE in regulating uPA expression and cell migration using highly metastatic androgen-independent PC3 prostate cancer cells as a model. GSE down-regulated uPA as a function of concentration. Additional studies showed that GSE inhibited DNA-binding activity of the transcription factor nuclear factor kappa B (NFkappaB), which in turn decreased NFkappaB-dependent uPA transcription. Invasion assays revealed the inhibitory effect of GSE on PC3 cell migration. These in-vitro experiments demonstrate the therapeutic property of GSE as an antimetastatic agent by targeting uPA.

Bikunin loss in urine as useful marker for bladder carcinoma

PURPOSE

We searched for bladder tumor markers by analyzing urine samples from patients with bladder cancer and normal individuals.

MATERIALS AND METHODS

Proteins in urine samples of patients with cancer and normal subjects were systematically examined by 2-dimensional electrophoresis combined with matrix assisted laser desorption ionization time-of-flight mass spectrometry. Of the proteins bikunin expression was confirmed by Western blot analysis and further evaluated. To correlate urinary bikunin levels with clinical significance we examined urine samples from patients with bladder cancer and normal controls for bikunin expression in parallel with pro-urolinase-plasminogen activator, which was previously shown to be associated with advanced bladder carcinoma.

RESULTS

A significant relationship was established between the low level and absence of bikunin, and pro-urolinase-plasminogen activator in urine samples from patients with bladder tumors.

CONCLUSIONS

Analysis of urinary proteomes may be a feasible, noninvasive and efficient strategy for searching for potential bladder tumor biomarkers. We identified bikunin loss in urine as a potential bladder carcinoma marker.

Intravesical administration of plasminogen activator inhibitor type-1 inhibits in vivo bladder tumor invasion and progression

PURPOSE

The potent effects of PAI-1 on tumorigenesis and angiogenesis in various experimental models are complex, complicated and at times contradictory. We determined the therapeutic potential of PAI-1 for inhibiting bladder tumor invasion under conditions that closely mimic the clinical setting.

MATERIALS AND METHODS

An orthotopic rat bladder tumor model was established by implanting AY-27 rat transitional carcinoma cells into the bladder lumen of syngeneic Fischer F344 rats. Three weeks after implantation 1 microM PAI-1 was administrated directly into the bladder lumen twice weekly for 2 weeks. Two days after the final treatment tumor size, total bladder weight, tumor stage and angiogenesis were assessed. To assess the uPA axis the levels of active and total uPA, and active and total PAI-1 in tumor extracts were determined 0, 2, 24 and 48 hours after intravesical PAI-1 administration.

RESULTS

Intravesical PAI-1 bound and inactivated its molecular target, tumor uPA. There was significant inhibition of bladder tumor progression, as manifested by 53%, 37% and 57% reductions in tumor size, total bladder weight and angiogenesis, respectively. Only 22% of PAI-1 treated tumors invaded muscle vs 79% in controls. No PAI-1 toxicity was detected.

CONCLUSIONS

To our knowledge this study is the first to demonstrate that intravesical treatment with PAI-1 significantly inhibits tumor progression in an in vivo model of bladder cancer. Further clinical development is warranted for using PAI-1 directly or in combination with current standards, such as bacillus Calmette-Guerin or interferon.

Targeting urokinase-type plasminogen activator and its receptor for cancer therapy

Cancer invasion and metastasis are highly complex processes and a serine protease urokinase-type plasminogen activator/urokinase-type plasminogen activator receptor system has been postulated to play a central role in the mediation of cancer progression. Of note, malignant tumor urokinase-type plasminogen activator and urokinase-type plasminogen activator receptor levels have been found to vary considerably, and to be related to patient prognosis. In mouse models, the urokinase-type plasminogen activator/urokinase-type plasminogen activator receptor system has been studied extensively as a target for anticancer therapy using a variety of approaches. In this review, we discuss the advances in the various modalities that have been used to target the urokinase-type plasminogen activator/urokinase-type plasminogen activator receptor system, including protein-based and peptide-based drugs, antisense therapy, and RNA interference technology. In particular, preclinical mouse model studies that used human tumor xenografts are reviewed.

Searching cell-secreted proteomes for potential urinary bladder tumor markers

To search for biomarkers critical for bladder carcinoma diagnosis and prognosis, secreted proteomes of highly malignant U1 and pre-malignant U4 cell lines were initially analyzed. Proteins in the culture media of the U1 and U4 cell lines were systematically examined by SDS-PAGE combined with MALDI-TOF MS. Among them, expression of pro-u-plasminogen activator (pro-u-PA) was confirmed by Western blot analysis and further evaluated. In analyzing urine samples from bladder cancer patients and normal subjects, we established a statistically significant relationship between the low level and absence of pro-u-PA in urine with high stages and grades of the tumor samples. Constitutive expression of Ras dominant negative protein led to increased expression of pro-u-PA in culture media, indicating that the loss of pro-u-PA is associated with oncogenic transformation. Analysis of cancer-secreted proteomes can be a feasible, non-invasive and efficient strategy for searching potential bladder tumor biomarkers. Our work also has identified the loss of pro-u-PA in urine as potential marker of more advanced bladder carcinoma.

Association of interleukin-8 and plasminogen activator system in the progression of colorectal cancer

The aim of this study was to investigate the relationship of Interleukin-8 (IL-8) with vascular endothelial growth factor (VEGF) and plasminogen activator system (PA system) in the progression of colorectal cancer (CRC). In eighty-seven patients with CRC, the levels of IL-8, and VEGF as representative angiogenic factors and urokinase-type plasminogen activator (uPA), uPA receptor (uPAR), plasminogen activator inhibitor-1 (PAI-1), and PAI-2 as representative invasive factors were quantitatively assayed in tumor and adjacent normal tissues. The levels of IL-8, VEGF, and PA system factors in tumor tissues were all significantly higher than those in normal tissues. The IL-8 level was significantly associated with tumor size, depth of infiltration, Dukes stage, and liver metastasis, and also significantly correlated with the levels of VEGF, uPAR, uPA, and PAI-1. The VEGF level was significantly associated with tumor size, vascular involvement. The levels of uPAR and PAI-1 were significantly associated with tumor size and depth of infiltration, and the uPAR level was associated with liver metastasis. The VEGF level was significantly correlated with the levels of uPAR and PAI-1. These results reveal that IL-8, VEGF, and PA system factors are contributed to tumor growth, invasion, and metastasis in CRC. Univariate analysis revealed that high levels of IL-8, VEGF, and uPAR were significantly associated with a shorter overall survival time; however, multivariate analysis identified only liver metastasis as an independent prognostic factor. In conclusion, IL-8 is responsible to tumor progression and liver metastasis of CRC, and the activation of PAS induced by IL-8 as well as VEGF may play an important role in the progression of CRC.

Tissue-type plasminogen activator (tPA) in breast cancer: relationship with clinicopathological parameters and prognostic significance

BACKGROUND

Tissue-type plasminogen activator (tPA) is a serine protease primarily involved in the intravascular dissolution of blood clots. High intratumoral tPA levels are associated with prognosis in several human tumors. In addition, tPA has been shown to be an estrogen-inducible protein in human breast cancer cell lines. The aim of the present study was to analyze the cytosolic tPA content in primary breast carcinomas and its potential clinical value.

MATERIALS AND METHODS

tPA was measured by a solid-phase enzyme immunoassay in tumor cytosol samples obtained from 800 patients with breast cancer. The median follow-up period was of 49.2 months.

RESULTS

Cytosolic tPA levels ranged widely in breast carcinomas (median: 3.9; range: 0.1- 315.3 ng/mg protein). tPA levels were significantly lower in large tumors, as well as in those showing poor differentiation, estrogen (ER) or PgR-negativity, aneuploidy, or a high S-phase fraction. In addition, low tPA intratumoral levels were associated with a high probability of both shortened relapse-free and overall survival in all patients and in the subgroup with node-negative tumors. However, our results did not show any significant relationship between intratumoral tPA levels and prognosis in the different subgroups of patients, stratified according to the type of systemic adjuvant therapy received (chemotherapy, tamoxifen or chemotherapy plus sequential tamoxifen).

CONCLUSION

The results of the present investigation indicate that low intratumoral tPA levels are associated with aggressiveness and poor prognosis in breast cancer patients. However, the study suggests that tPA levels do not predict response to systemic adjuvant therapy.

Metastasis markers in bladder cancer: a review of the literature and clinical considerations

Cancer invasion and metastasis develop through a sequence of processes involving loss of cell-cell and cell-matrix adhesions, proteolysis and induction of angiogenesis. We reviewed the current literature on the molecules that have been shown to play a significant role in these three steps of metastatisation in bladder cancer (BC) cells and their host microenvironment. Particular emphasis was given to markers that are assessable through immunohistochemistry and for which an additional prognostic value over the TNM variables has been recognized, in order to identify a subset of tumour markers readily available for application in daily clinical practice. We conclude that markers such as E-cadherin, Sialosyl-LeX, laminin, collagen IV, TSP-1 and MVD are useful prognostic markers, alpha, beta, and gamma catenin, MMP-2 and -9, uPAR, PD-ECGF and Bfgf can be considered potentially useful, while research on CD44, MMP-1 and -3, uPA, cathepsin D and VEGF has proved inconclusive. Further research in this field should concentrate on the molecules listed in the first group.

The urokinase plasminogen activator system: a rich source of tumour markers for the individualised management of patients with cancer

The urokinase plasminogen activator (uPA) system consists of the serine protease uPA, the glycolipid-anchored receptor, uPAR, and the 2 serpin inhibitors, plasminogen activator inhibitor-1 (PAI-1) and plasminogen activator inhibitor-2 (PAI-2). Recent findings suggest that uPA, uPAR and PAI-1 play a critical role in cancer invasion and metastasis. Consistent with their role in cancer dissemination, high levels of uPA, PAI-1 and uPAR in multiple cancer types correlate with adverse patient outcome. The prognostic value of uPA/PAI-1 in axillary node-negative breast cancer patients was recently validated using both a prospective randomised trial and a pooled analysis. Assay of uPA and PAI-1 may thus help identify low-risk node-negative patients for whom adjuvant chemotherapy is unnecessary. Finally, emerging data suggest that high levels of uPA and PAI-1 in breast cancer are associated with a preferential response to adjuvant chemotherapy but relative resistance to hormone therapy. The measurement of uPA components, especially in breast cancer, thus has the potential to help with individualised patient management.

Molecular biology of transitional cell carcinoma

Transitional cell carcinoma (TCC) is the fifth most common solid malignancy in the USA. Radical cystectomy will cure a substantial fraction of patients with minimally invasive TCC, but approximately 50% of patients with muscle-invasive or extravesical disease treated by radical cystectomy alone die of metastatic TCC. Transitional cell carcinoma have a diverse collection of biologic and functional characteristics. This is reflected in a differing clinical course. The limited value of established prognosticators, make the analysis of new molecular parameters of interest in predicting the prognosis of bladder cancer patients; in particular, high-risk patient groups that are at risk of progression and recurrence. Over the past decade, there had been major progress in the elucidation of the molecular genetic changes leading to the development of TCC. This review will highlight these important advances and emphasize the ways in which molecular biology is likely to affect the development of future therapies.

Current understanding of the biology of advanced bladder cancer

Transitional cell carcinoma (TCC) is reported to be the fifth most common solid malignancy in the U.S. Although radical cystectomy will cure a substantial number of patients with minimally invasive TCC, many patients with deeply muscle-invasive or extravesical disease who are treated with radical cystectomy alone die of metastatic TCC, as do patients with metastatic disease. The differing clinical course and the limited value of established prognosticators make analysis of new molecular parameters of interest in predicting the prognosis of patients with bladder cancer, particularly those in high-risk groups who are at risk of disease progression and recurrence. In the current review, a comprehensive MEDLINE/PubMed search of articles pertaining to the biology of TCC from 1965 to the present was performed, as well as a bibliographic review of cross references. TCC follow the general concept of multistep carcinogenesis and proceed through two distinct genetic pathways responsible for generating different TCC morphologies, namely the inactivation of cyclin-dependent kinase inhibitors in low-grade TCC and early p53-mediated abnormalities in high-grade TCC. TCC progression correlates with genetic instability and the accumulation of collaborative genetic lesions mainly involving p53, retinoblastoma, and growth factors. The bulk of these data are derived from cases of localized/locally advanced disease and none are ready yet for routine clinical application; however, the current knowledge has led to the clinical testing of novel biologic observations in several important trials. Understanding of the molecular biology of advanced bladder cancer continues to improve. It is likely that in the new millennium, real breakthroughs in the identification and therapy of high-risk, poor-prognosis patients will come from an integration of molecular modalities in the clinical application.

Prognostic significance of tissue-type plasminogen activator (tPA) content in gastric cancer and surrounding mucosa

AIMS

We analyzed the tPA content in primary gastric carcinomas and surrounding mucosa in order to assess the relationship between tPA content, clinicopathological tumor characteristics, and estrogen and progesterone receptor content. We evaluated the prognostic value of this serine protease in gastric cancer patients.

PATIENTS AND METHODS

122 resected gastric neoplasms and 95 adjacent mucosa samples were studied. The tPA content was measured in cytosol by an ELISA method. Cytosolic ER and PgR were measured with a solid phase enzyme immunoassay.

RESULTS

Cytosolic tPA levels in neoplastic tissues (median 1.0 ng/mg prot) were significantly lower (p=0.002) than those found in paired mucosa samples (median 2.3 ng/mg prot). There was no significant association between tPA levels and clinicopathological parameters or PgR content, but tPA levels were significantly correlated with ER content. The intermediate-tPA-content group, corresponding to samples with between 0.3 and 1.70 ng/mg protein, proved to have a significantly high risk of relapse.

CONCLUSIONS

We found a wide variability in tPA levels in gastric carcinoma and adjacent mucosa samples, with significantly decreased levels in tumors and a significantly positive relationship between tPA levels and ER status. There was a non-monotonic relationship between tPA levels and prognosis in patients with gastric cancer.

Expression of UPA and UPAR is associated with the clinical course of urinary bladder neoplasms

The expression of urokinase plasminogen activator (uPA) and its receptor (uPAR) mRNA was determined in 194 subjects with newly detected bladder neoplasms, selected from a larger population-based series. An association was found between uPA and uPAR expression (n = 172; Spearman r(s) = 0.60, p < 0.001). Both uPA and uPAR mRNA levels were higher in muscle invasive (T2+) tumors than in noninvasive mucosal tumors (Ta) or those invading submucosa (T1). The relative hazard ratios (RHRs) for cancer-specific death associated with elevated expression (95% CI), adjusted for age and gender in a Cox proportional hazard model, were 1.8 (1.0-3.3) for uPA (upper quartile cut-line), 2.2 (1.3-4.0) for uPAR (median quartile cut-line) and 2.5 (1.3-4.9) for uPA + uPAR. An RHR for metastatic disease of 4.0 (1.6-9.9) was observed for uPAR. Restricting the analyses to T2+ tumors, the corresponding figures were: 2.1 (1.1-3.9) for uPA, 1.6 (0.8-3.3) for uPAR and 2.5 (1.1-5.6) for both. We conclude that expression of uPA and uPAR is associated with the clinical behaviour of bladder neoplasms, possibly providing means for refined staging of muscle invasive tumors and target proteins for novel therapies.

A selective plasmin inhibitor, trans-aminomethylcyclohexanecarbonyl-L-(O-picolyl)tyrosine-octylamide (YO-2), induces thymocyte apoptosis

The treatment of rat thymocytes with YO-2, a novel inhibitor of plasmin, resulted in an increase in DNA fragmentation. DNA fragmentation was also induced by another YO compounds such as YO-0, -3, -4 and -5. These YO compounds are the inhibitor of plasmin activity. On the other hand, YO-1, -6 and -8 that hardly inhibit plasmin activity had no effect on DNA fragmentation. Analysis of fragmented DNA from thymocytes treated with YO-2 by agarose gel electrophoresis revealed that the compound caused internucleosomal DNA fragmentation. In addition, judging from a laser scanning microscopy, annexin V-positive and propidium iodide-negative cells were increased by the treatment of the cells with the compound. Moreover, chromatin condensation was observed in thymocytes treated with the compound. These results demonstrated that YO-2 induces thymocyte apoptosis. There seemed to be some correlation between the apoptosis induced by YO compounds and their plasmin inhibitory effect. However, because the other protease inhibitors including pepstatin A, leupeptin, AEBSF, DFP and E-64-d did not affect DNA fragmentation, YO compounds are likely to have unique mechanism on plasmin or to show the effect on the other plasmin-like proteases. The plasmin inhibitory activity may have an important role in YO-2-induced apoptosis. Furthermore, the stimulations of caspase-8, -9 and -3-like activities were observed in thymocytes treated with YO-2. These results suggest that YO-2 induces thymocyte apoptosis via activation of caspase cascade.

Expression of three extracellular matrix degradative enzymes in bladder cancer

The relationship between expression of extracellular matrix degradative enzymes, angiogenesis and survival of multistage bladder cancer was determined. Expression of 3 extracellular matrix degradative enzymes (metalloproteinase-2, -9 and heparanase) and microvessel formation were examined in 40 resected bladder cancer specimens by immunohistostochemic staining, and then the association of the enzyme expression with angiogenesis and various stages of cancer was investigated. Heparanase protein expression in muscular invasive or lymph-node metastatic cancer was significantly higher than in superficial or nonmetastatic cancer, respectively (69% vs. 8%, p < 0.001, and 80% vs. 40%, p = 0.028, respectively). Interestingly, heparanase was expressed at much higher levels than matrix metalloproteinase-2 and -9. The mean microvessel count in cancers with heparanase expression was significantly higher than that in cancers without heparanase expression (32.3 +/- 18.2 vs. 5.5 +/- 6.1, p = 0.0008). The microvessel formation was not associated with the expression of matrix metalloproteinase-2 and -9. The cancer-specific and overall survival rates of patients with heparanase expression were significantly lower than those of patients without it (p = 0.0001 and p = 0.0008, respectively). Multivariate analysis showed that heparanase expression was a significantly independent prognostic factor for both cancer-specific (p = 0.0047) and overall survival (p = 0.0200). Our study suggested that heparanase plays important roles in invasion, angiogenesis and metastasis of bladder cancer, and thus, this molecule could be a new molecule to inhibit invasion, angiogenesis and metastasis of bladder cancer. Moreover, our results indicate that expression of heparanase could be a new prognostic factor of this disease.

Urokinase receptor and vascular endothelial growth factor are synergistically associated with the liver metastasis of colorectal cancer

Considering recent findings that the urokinase plasniinogen activation (PA) system is involved in invasion and vascular endothelial growth factor (VEGF) is involved in angiogenesis of colorectal cancer, we evaluated these factors in the liver metastasis of primary colorectal cancer. Cancer tissues from 71 colorectal cancer patients were assayed quantitatively for antigen levels of urokinase type plasminogen activator (uPA), uPA receptor (uPAR), and plasminogen activator inhibitor‐1 and ‐2 (PAI‐1, PAI‐2), and were also assayed immunohistochemically for expression of VEGF protein. Among the PA system factors, both the levels of uPAR and PAI‐1 were significantly higher in larger tumors than in smaller ones, and were also significantly higher in tumors that invaded subserosa, serosa or adjacent organs than in mucosal, submucosal tumors or in tumors that invaded the muscle layer. The uPAR levels were significantly higher in tumors with liver metastasis than in those without. VEGF overexpression was significantly more frequent in tumors with lymph node involvement or liver metastasis than in those without. Among the PA system factors, the uPAR levels were significantly higher in tumors with VEGF overexpression and a multivariate analysis revealed that high uPA level and VEGF overexpression were independent risk factors for liver metastasis. The combination of high uPAR level and overexpression of VEGF was associated with the worst prognosis in patients with colorectal cancer. These results suggest that uPAR and VEGF might contribute Synergistically to the liver metastasis of colorectal cancer.

Low interleukin-1alpha messenger RNA levels predict decreased overall survival time of patients with urinary bladder carcinoma

Due to our inability to exactly characterize tumours, many patients with urinary bladder cancer undergo unnecessary surgery or cytostatic therapy. We have here studied the expression of the cytokine interleukin-1alpha (IL-1alpha ) in 73 human bladder carcinomas in relation to patient survival, and examined possible relationships between IL-1alpha and urokinase plasminogen activator (uPA) expression. Expression levels of IL-1alpha and uPA mRNA were determined by RT-PCR using the quantitative TaqMan technique. The levels of IL-1alpha mRNA expression did not differ significantly between tumours of different grade or stage. Calculation of the overall survival rates showed a decreased overall survival time for patients with low levels of IL-1alpha mRNA in their tumours (log rank; P = 0.0002, median follow up: 37 months). Low tumoral IL-1alpha expression predicted decreased survival of patients with poorly differentiated tumours (P< 0.005) and of patients with invasive tumours (P = 0.02). uPA expression was about 4-fold increased in poorly differentiated tumours. High levels of uPA mRNA were associated with decreased overall survival times (log rank; P = 0.032, n = 60). We conclude that IL-1alpha is important for bladder cancer biology, and that measurements of this cytokine may be useful in pre-treatment characterization of urinary bladder cancer.

Clinical relevance of urokinase-type plasminogen activator, its receptor, and its inhibitor type 1 in endometrial cancer

OBJECTIVE

Tumor invasion involves degradation of extracellular matrix. The urokinase plasminogen activation system participates in this process. Urokinase-type plasminogen activator (uPA), its receptor (uPAR), and its inhibitor, plasminogen activator inhibitor type 1 (PAI-1), are proposed to be prognostic factors in some cancers. There are conflicting data regarding the prognostic role of this system in endometrial cancer.

METHODS

To determine the prognostic value of the urokinase plasminogen activation system, contents of uPA, uPAR, and PAI-1 were measured in extracts of endometrial cancer tissue using ELISAs. uPA, uPAR, and PAI-1 levels were determined in 91, 54, and 92 extracts, respectively, and correlated with tumor histology, stage, grade, lymph node involvement, prevalence of metastasis, and recurrence as well as with estrogen (ER), progesterone (PR), epidermal growth factor (EGFR) receptor and HER-2/neu contents.

RESULTS

Patients with cancers exhibiting advanced stage, high grade, unfavorable tumor histology, nodal involvement, recurrence, and lower PR levels determined by ligand binding had significantly higher uPA content than others. PAI-1 was significantly elevated in patients with advanced stage, high-grade tumor, recurrence, decreased ER content, and lower PR levels determined by ligand binding. uPAR did not show any relation to any of clinical and laboratory parameters. Elevated expression of PAI-1 was associated with significantly shorter disease-free (P = 0.005) and overall (P = 0.0003) survival. Multivariate analysis revealed that PAI-1 was a predictor of survival although stage was the strongest independent factor.

CONCLUSION

Elevated uPA and PAI-1 levels appear to correlate with unfavorable prognosis in endometrial cancer.

Serum signaling factors and spheroids

Normal epithelial cells grow as a sheet-like structure. Upon malignant transformation, epithelial cells grow as multicell aggregates. Adopted in tissue culture, most tumor cells revert to adherent monolayer. In tissue culture, as early as 1958, anchorage-independent multicellular spheroid cancer cells have been shown to revert to adherent monolayer in response to extracellular serum signaling factors. Such serum signaling factors have not yet been characterized. Recent studies reveal that the conversion of adherent monolayer to multicellular spheroids is also mediated by serum signaling factors such as carcinoembryonal antigen, interferon-gamma, insulin-like growth factor-II, heregulin beta1 and plasmin. The reports provide a new approach to investigate the regulatory system of tumor cell growth pattern as well as the effect of the change in growth pattern on various cellular functions.

Clinical relevance of urokinase-type plasminogen activator, its receptor and inhibitor type 1 in ovarian cancer

Urokinase-type plasminogen activator (uPA), its receptor (uPAR) and inhibitor, plasminogen activator-type 1 (PAI-1) are proposed to be of prognostic significance in some cancers. To determine the prognostic value of the urokinase plasminogen activation system in ovarian cancer, levels of uPA, uPAR, and PAI-1 were measured in extracts of ovarian cancer tissue using ELISA tests. uPA and PAI-1 were determined in 70 tumor extracts and uPAR in 43 extracts. Levels were correlated with age, tumor histology, stage, grade, lymph node and metastatic status, residual disease, risk of recurrence, epidermal growth factor receptor (EGFR) expression, cathepsin D (Cath-D), and c-erbB-2 levels. uPA and uPAR did not exhibit correlation with any of these parameters. However, patients with high grade tumor, recurrence, and lower EGFR and Cath-D had significantly higher PAI-1 levels compared to those of others (P < 0.05). Kaplan-Meier plots of survival were compared. uPA and uPAR were not related to disease-free or overall survival. Although low PAI-1 appeared to predict a longer overall survival, the difference was not statistically significant. Multivariate analysis revealed that PAI-1 was a predictor for overall survival although it was not as strong as stage. These results suggest that elevated PAI-1 seems to be correlated with an unfavorable prognosis in ovarian cancer.

Independent prognostic value of serum hepatocyte growth factor in bladder cancer

PURPOSE

We retrospectively investigated whether the level of serum hepatocyte growth factor could predict the prognosis and extent of transitional-cell carcinoma of the urinary bladder.

PATIENTS AND METHODS

Serum samples were collected from 113 patients with bladder cancer and from 200 healthy controls. Of the 113 patients, 59 had superficial bladder cancer and 54 had muscle-invasive cancer. Thirteen bladder cancer tissues (eight superficial and five muscle-invasive) were also collected. The levels of hepatocyte growth factor in the serum and tissues of these individuals were measured by enzyme-linked immunoadsorbent assay using hepatocyte growth factor antibodies.

RESULTS

The levels of hepatocyte growth factor in the serum and tissues of patients with muscle-invasive cancer were significantly higher than those of patients with superficial bladder cancer (P <.0001 and P =.0054, respectively). The degree of elevation above the normal level of serum hepatocyte growth factor of the former (61.1%) was significantly higher than that of the latter (8.4%; P <.0001). The elevation was highest in patients with visceral metastasis (93.3%). Among patients with superficial bladder cancer, the overall survival rate of those with low levels of serum hepatocyte growth factor was significantly greater than that of those with high levels (P =.005). Among patients with minimally invasive bladder cancer, the disease-free and overall survival rates of those with high levels of serum hepatocyte growth factor were significantly lower than the same rates of those with low levels (P <.001 and P =.0028, respectively).

CONCLUSION

Our study suggests that the level of hepatocyte growth factor in serum could be a predictor of patient survival and extent of bladder cancer.

H-ras and Nm23-H1 gene expression and proteolytic activity in squamous cell carcinoma of the uterine cervix

BACKGROUND

The invasive and metastatic potential of malignant cells results from complex interactions of numerous factors not yet fully understood. Genomic alterations such as ras overexpression and nm23-H1 inhibition have been found to be frequently associated with increased invasiveness in various cancers. On the other hand, secretion of different proteinases are necessary for malignant cells to traverse a network of matrix macromolecules, but the relationship between the genomic alterations and the proteolytic phenotype is still unclear. Our aim was to investigate whether the appearance of the proteolytic phenotype had any correlation with the expression of H-ras and nm23-H1 genes in carcinoma of the uterine cervix.

METHODS

Twenty-five samples from patients with carcinoma of the uterine cervix at different clinical stages were studied. Cathepsin B1, plasminogen activator, and collagenase activity were assessed in tissue cytosols using specific synthetic oligopeptides as substrates. The expression of H-ras and nm23-H1 was investigated by means of immunohistochemistry and in situ hybridization.

RESULTS

Our results showed that cathepsin B1 was the most consistently elevated proteinase, demonstrating a linear correlation with clinical staging. H-ras expression was found elevated in 40% of the cases. Nm23-H1 protein immunoreactivity was positive in 40% of the cases. No correlation was found among H-ras, cathepsin B1 activity, and survival rate. Among cases with high cysteine proteinase activity, a different clinical behavior depending on the expression of Nm23-H1 was observed. The cases with Nm23-H1 protein had a markedly better survival rate than those lacking this protein. In contrast, the absence of Nm23-H1 in association with high cathepsin B1 activity was a clear indicator of a poor prognosis.

CONCLUSIONS

These findings suggest a complex interaction between the proteolytic phenotype and the expression of H-ras and nm23-H1 genes in carcinoma of the cervix that influences the clinical behavior of the tumor.

Larger and more invasive colorectal carcinoma contains larger amounts of plasminogen activator inhibitor type 1 and its relative ratio over urokinase receptor correlates well with tumor size

BACKGROUND

Considering recent findings that both urokinase plasminogen activator receptor (uPAR) and plasminogen activator inhibitors (PAIs) are involved in tumor growth through an urokinase-type plasminogen activator (uPA) activity-independent mechanism, the relation between the presence of these factors in tumor tissue and the clinicopathologic variables in colorectal carcinoma was reevaluated.

METHODS

In 100 colorectal carcinoma patients, antigen levels of u-PA, uPAR, and PAI-1 and PAI-2 were assayed in both tumor tissues and their normal counterparts. Plasma levels of soluble uPAR also were determined.

RESULTS

All uPAR, uPA, PAI-1, and PAI-2 antigen levels in tumor tissue were significantly higher than those in normal tissue. Levels of both uPAR and PAI-1 were significantly higher (3.09 +/- 1.37 and 6.63 +/- 7.49, respectively) in large tumors (>/=50 mm in greatest dimension) than those in smaller tumors (< 50 mm) (2.50 +/- 1.07 and 2.72 +/- 2.70, respectively) (P < 0.05). Significant positive correlation coefficients (r) were obtained between tumor size and the calculated ratios of PAI-1/uPAR (r = 0.490; P < 0.0001) and PAI-1/uPA (r = 0. 469; P < 0.0001). In addition to liver metastases (P = 0.004) and lymph node involvement (P = 0.04), high levels of uPAR (P = 0.05) also were found to be of independent prognostic value by multivariate analysis.

CONCLUSIONS

Higher expression of uPAR was related to poor prognosis of patients with colorectal carcinoma and excess amounts of PAI-1 over uPAR or uPAR-bound uPA appeared to play an important role in tumor progression.

Urokinase plasminogen activator: a prognostic marker in multiple types of cancer

Urokinase plasminogen activator (uPA) is a serine protease causally involved in cancer invasion and metastasis. Consistent with its role in cancer spread, uPA has been shown to be a prognostic marker in a variety of malignancies, especially breast cancer. Approximately 20 different groups have shown that high levels of uPA in breast tumor tissue predict poor outcome. As a prognostic marker in breast cancer, uPA provides information that is independent of traditionally used factors such as tumor size, tumor grade, axillary node status and estrogen receptor status. Furthermore, uPA is prognostic in node-negative patients, and a clinical trial is currently under way to assess whether uPA and its inhibitor, plasminogen activator inhibitor-1, can differentiate between the majority of node-negative breast cancer patients who are cured by surgery from the minority who might benefit from adjuvant therapy. uPA is also prognostic in other malignancies, such as gastric, colorectal, esophageal, renal, endometrial, and ovarian cancers. uPA may thus be a prognostic indicator for multiple types of adenocarcinoma.

Expression of Met protein and urokinase-type plasminogen activator receptor (uPA-R) in papillary carcinoma of the thyroid

Met protein encoded by MET oncogene is the high affinity receptor for hepatocyte growth factor (HGF)/scatter factor (SF). HGF/SF has to be cleaved in its heterodimeric form by the urokinase-type plasminogen activator (uPA) to become active as a ligand for Met receptor. The expression of Met protein and of the high affinity receptor for uPA (uPA-R) was investigated in 39 samples of papillary carcinoma using immunohistochemistry. Reactivity for Met protein was present in 33 of 34 tumours, mostly with a diffuse pattern of staining. Reactivity for uPA-R was present in 78 per cent of papillary tumours and exhibited a pattern of staining similar to that of Met protein. Staining for uPA-R was present in 23 of 25 cases (92 per cent) of papillary carcinoma with prominent sclerosis, and in only 1 of 7 cases (14 per cent) without sclerosis. Peritumoural normal thyroid, follicular adenomas, and follicular carcinomas were negative for Met protein and for uPA-R. Hyperfunctioning tall thyroid cells showed weak membrane reactivity for uPA-R and for Met protein. The findings of immunohistochemistry were confirmed at the mRNA level using in situ hybridization, since the signal for uPA-R and Met RNAs was detected in most tumour cells of five cases of papillary carcinoma.

Prognostic value of urokinase plasminogen activator in primary breast carcinoma: comparison of two immunoassay methods

Urokinase-type plasminogen activator (uPA) is a potentially important prognostic factor in breast cancer for identifying patients at high risk of recurrence. This retrospective study assessed two enzyme-linked immunosorbent assay (ELISA) methods measuring uPA antigen levels in 499 primary breast cancer cytosols. Both uPA methods were applied to cytosols used routinely for oestrogen (ER) and progesterone (PgR) receptor assays. uPA was determined using a classical ELISA method (Imubind; American Diagnostica) and a novel automatic immunoluminometric assay (Lia; Sangtec Medical). The uPA Imubind method revealed about twice as much uPA antigen (median 0.75 ng mg(-1) protein) as the uPA Lia method (median 0.38 ng mg(-1) protein). The correlation coefficient between the two methods was acceptable (r = 0.81), but the two techniques are not interchangeable. Univariate analyses confirmed the poor outcome of patients whose tumours contained large amounts of uPA, regardless of the technique used. Multivariate analyses showed that uPA Imubind and uPA Lia values were both strong independent prognostic factors.

Urokinase-type plasminogen activator, its inhibitor, and its receptor in patients with upper urinary tract carcinoma

BACKGROUND

Urokinase-type plasminogen activator (uPA) is a serine protease involved in tumor invasion and metastasis. Its activity during metastasis may be regulated by a plasminogen activator inhibitor (PAI). Furthermore, uPA exerts its action by binding to a membrane-bound receptor (uPAR). The authors attempted to examine the immunohistochemical expression of uPA, uPAR, and PAI-1 in patients with transitional cell carcinoma of the upper urinary tract (TCC-UUT).

METHODS

Formalin fixed, paraffin embedded tumor tissues from 154 patients were analyzed using immunohistochemical staining.

RESULTS

There was moderate to strong cytoplasmic staining for uPA, PAI-1, and uPAR in 57.8%, 96.1%, and 88.3%, respectively, of tumor epithelial cells, and in 22.7%, 53.9%, and 24.7%, respectively, of stromal cells at the tumor/stroma interface. Examination of the relationship between immunoreactive score and clinicopathologic findings revealed that the uPA score for stromal cells significantly correlated with the stage and pattern of growth of the tumors. The PAI-1 score for tumor epithelial cells and the uPAR score for stromal cells both correlated with stage, grade, and pattern of growth. The PAI-1-score for stromal cells correlated with stage and grade. The uPAR-score for tumor epithelial cells correlated with stage. When only the immunoreactive scores that were classified as "high" (if the score was > or = 5 or > or = 1, for tumor epithelial and stromal cells, respectively) were considered, univariate analysis revealed that a "high" PAI-1 score for tumor epithelial cells and a "high" uPAR score for stromal cells both were significantly associated with poor disease free and overall survivals, particularly early period survival. In the final models of the multivariate analysis, only stage (all periods, disease free survival and overall survival), and grade (12 months, overall survival) were found to be progressive or prognostic factors.

CONCLUSIONS

Detection of immunoreactivity for plasminogen activator parameters appears to be of little or no value in determining the prognosis of patients with TCC-UUT, although some parameters were found to be associated with high stage or high grade of the tumors.

Suppression of metastatic potential and up-regulation of gelatinases and uPA in LLC by protracted in vivo treatment with dacarbazine or razoxane

Treatment of mouse Lewis lung carcinoma with razoxane or dacarbazine was protracted for 10 transplant generations. While the capacity of the treated tumors to grow locally in immuno-competent or in immuno-depressed hosts was retained and not significantly modified, the metastatic phenotype was eliminated when the treated tumor cells were transplanted into immuno-competent hosts. The reduction in metastatic potential was slightly less pronounced, in terms of both number and volume of metastases, when the treated tumor cells were transplanted into immuno-depressed hosts. These properties were retained after 3 transplant generations without treatment. Northern blotting and zymography of primary-tumor crude extracts revealed that treatment with either razoxane or dacarbazine for one generation approximately doubled the expression of MMP-2 and MMP-9, while lacking any effect on that of 1.0 and of 3.5 kb TIMP-2. When the treatment was maintained for 10 generations, the expression of MMP-2 and MMP-9 for both drugs showed up-regulation of approximately 10- and 2-fold respectively. TIMP-2 mRNA of 1.0 kb doubled its expression, while that of 3.5 kb registered just above the control. Dacarbazine doubled the expression of uPA after 10 generations, while razoxane boosted it approximately 3-fold after either 1 or 10 generations. The permanent loss of metastatic phenotype induced in Lewis lung carcinoma by dacarbazine and razoxane is thus attributable to biological mechanisms independent of down-regulation of expression and/or activation of the 2 gelatinases.

The urokinase-type plasminogen activator system in cancer metastasis: a review

The urokinase-type plasminogen activator (u-PA) system consists of the serine proteinases plasmin and u-PA; the serpin inhibitors alpha2-anti-plasmin, PAI-1 and PAI-2; and the u-PA receptor (u-PAR). Two lines of evidence have strongly suggested an important and apparently causal role for the u-PA system in cancer metastasis: results from experimental model systems with animal tumor metastasis and the finding that high levels of u-PA, PAI-1 and u-PAR in many tumor types predict poor patient prognosis. We discuss here recent observations related to the molecular and cellular mechanisms underlying this role of the u-PA system. Many findings suggest that the system does not support tumor metastasis by the unrestricted enzyme activity of u-PA and plasmin. Rather, pericellular molecular and functional interactions between u-PA, u-PAR, PAI-1, extracellular matrix proteins, integrins, endocytosis receptors and growth factors appear to allow temporal and spatial re-organizations of the system during cell migration and a selective degradation of extracellular matrix proteins during invasion. Differential expression of components of the system by cancer and non-cancer cells, regulated by paracrine mechanisms, appear to determine the involvement of the system in cancer cell-directed tissue remodeling. A detailed knowledge of these processes is necessary for utilization of the therapeutic potential of interfering with the action of the system in cancers.

Urokinase-type plasminogen activator receptor in gastric cancer: tissue expression and prognostic role

The urokinase-type plasminogen activator (UPA) and its inhibitor PAI-1 are thought to play an important part in gastric cancer (GC) invasion and metastasis. Little is known about the behavior and prognostic impact of the receptor for UPA (UPAR). The aims of the present study were: (1) to measure UPAR, UPA and PAI-1 levels in GC and in non-malignant tissue distant from the tumor (NORM); (2) to evaluate their relationship with histomorphological parameters; and (3) to determine their prognostic value. UPAR, UPA and PAI-1 levels were determined by ELISA in GC and NORM samples from 20 patients with GC undergoing surgery. The GC was also examined in terms of the presence (n = 10) or absence (n = 10) of metastasis, differentiation (five differentiated, 15 undifferentiated) and histotype. Survival was analysed using life table analysis. UPAR, UPA and PAI-1 were significantly higher in GC vs NORM, in the presence of metastasis (UPAR, UPA) and in undifferentiated GC (UPAR, PAI-1). UPAR significantly correlated with UPA and PAI-1. Low levels of UPAR (P = 0.04), UPA (P = 0.007) and PAI-1 (P = 0.02) were associated with a better survival. Our results demonstrate a sharp increase in UPAR in GC and suggest a prognostic role for it. The concomitant activation of UPAR, UPA and PAI-1 in GC confirm the important role of the plasminogen activator system in the process of invasion and metastasis.

Urokinase and the urokinase receptor: association with in vitro invasiveness of human bladder cancer cell lines

BACKGROUND AND PURPOSE

The plasminogen activators urokinase and tissue plasminogen activator are enzymes that degrade proteins in tissue basement membranes and the extracellular matrix (a biomolecular complex surrounding individual cells in tissues that serves as a barrier between the cells and the vascular and lymph systems). The action of these enzymes allows tumor cells to escape their local environment and metastasize. Plasminogen activator activity can be influenced by the urokinase receptor, which is expressed on the surface of cells, and by the plasminogen activator inhibitors 1 and 2. Because bladder tumors differ in their propensity to invade local areas and distant sites, we studied the expression of both plasminogen activators, the two plasminogen activator inhibitors, and the urokinase receptor in four human bladder cancer cell lines (RT4, 253J, EJ, and T24) to see if there was an association between the expression of these proteins and tumor cell invasiveness in vitro.

METHODS

The expression of urokinase, tissue plasminogen activator, and the two inhibitors was measured by enzyme-linked immunosorbent assays of serum-free, cell-conditioned media (i.e., culture fluids). Cell surface expression of the urokinase receptor was assayed by flow cytometry, using an anti-receptor monoclonal antibody (Mab3936). The invasive capacity of untreated cells and of cells exposed to exogenous, high-molecular-weight urokinase was analyzed by use of Matrigel invasion chambers.

RESULTS

The four bladder cancer cell lines demonstrated differential expression of both plasminogen activators and both inhibitors; three of the cell lines (T24, EJ, and 253J) expressed the urokinase receptor. The four cell lines differed in their invasive potential in vitro. Neither expression of tissue plasminogen activator nor production of the inhibitors appeared to influence Matrigel invasion. EJ cells and 253J cells produced the highest levels of urokinase and demonstrated the greatest propensity for invasion; T24 cells, which produced only small amounts of urokinase, exhibited a low invasive potential. Pretreatment of T24 cells with exogenous high-molecular-weight urokinase markedly increased their invasiveness. Similar pretreatment of EJ and 253J cells increased their invasiveness as well. RT4 cells, which lacked urokinase receptor expression but produced moderate amounts of urokinase, were not invasive and did not become so after exposure to exogenous high-molecular-weight urokinase. Binding of Mab3936 to urokinase receptors inhibited Matrigel invasion.

CONCLUSIONS

To our knowledge, this is the first study demonstrating that bladder tumor cells express the urokinase receptor and that both receptor expression and urokinase expression are required for bladder tumor cell invasion in vitro.

Contribution of plasminogen activators and their inhibitors to the survival prognosis of patients with Dukes' stage B and C colorectal cancer

Despite the advances in pre-, peri- and post-operative medical care of colorectal carcinoma patients, the prognosis has improved only marginally over recent decades. Thus, additional prognostic indicators would be of great clinical value to select patients for adjuvant therapy. In previous studies we found that colorectal carcinomas have a marked increase of the urokinase-type of plasminogen activator (u-PA), and the inhibitors PAI-1 and PAI-2, whereas the tissue-type plasminogen activator (t-PA) is found to be decreased in comparison with adjacent normal mucosa. In the present study we evaluated the prognostic value of several plasminogen activation parameters, determined in both normal and carcinomatous tissue from colorectal resection specimens, for overall survival of 136 Dukes' stage B and C colorectal cancer patients, in relation to major clinicopathological parameters. Uni- and multivariate analyses indicated that a high PAI-2 antigen level in carcinoma, a low t-PA activity and antigen level and a high u-PA/t-PA antigen ratio in adjacent normal mucosa are significantly associated with a poor overall survival. A high ratio of u-PA antigen in the carcinomas and t-PA antigen in normal mucosa, i.e. u-PA(C)/t-PA(N), was found to be predictive of a poor overall survival as well. All these parameters were found to be prognostically independent of the clinicopathological parameters. Multivariate analysis of combinations of these prognostically significant plasminogen activation parameters revealed that they are important independent prognostic indicators and have in fact a better prognostic value than their separate components. Based on these combined parameters, subgroups of patients with Dukes' stage B and C colorectal cancer could be identified as having either a high or a low risk regarding overall survival. In conclusion, these findings emphasize the relevance of the intestinal plasminogen activation system for survival prognosis of patients with colorectal cancer and, in the future, might constitute a patient selection criterion for adjuvant therapy.

Up-regulation of urokinase-type plasminogen activator in squamous cell carcinoma of human larynx

The expression of urokinase-type plasminogen activator (uPA) was investigated in squamous cell carcinoma of the human larynx. For this purpose, tissue extracts from 25 matched samples of normal mucosa and neoplastic larynx were compared for the levels of uPA activity as evaluated by a chromogenic PA assay and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) zymography. Also, uPA antigen was quantified by enzyme-linked immunosorbent assay (ELISA) in 19 cases. The results demonstrate a significant increase in the levels of uPA activity and protein in tumour tissue extracts, more pronounced in tumours with lymph node metastases. Immunohistochemistry performed on 70 biopsies showed that uPA positivity is present both in neoplastic cells and in fibroblast-like cells and macrophages. However, depending on the histological grading and invasive capacity of the tumour, a pronounced intra- and intertumoral heterogeneity in uPA staining was observed. In situ hybridisation confirmed the presence of uPA mRNA in both tumour and stromal cells. The present study provides experimental evidence for a role of uPA in the invasive growth of human laryngeal carcinoma.