High level of urokinase-type plasminogen activator is a new prognostic marker in patients with gastric carcinoma

Expression of Serpin Family E Member 1 (SERPINE1) Is Associated with Poor Prognosis of Gastric Adenocarcinoma

BACKGROUND

The aberrant expression of serpin family E member 1 (SERPINE1) is associated with carcinogenesis. This study assessed the alteration of SERPINE1 expression for an association with gastric adenocarcinoma prognosis.

METHODS

The Cancer Genome Atlas (TCGA) dataset was applied to investigate the impact of SERPINE1 expression on the survival of patients afflicted with gastric cancer. Subsequently, 136 samples from the Affiliated Huaian No. 1 People's Hospital of Nanjing Medical University were subjected to qRT-PCR and Western blot to validate the expression level of SERPINE1 between tumor and adjacent normal tissues. The correlation between the expression of SERPINE1 with the clinicopathological features in TCGA patients was analyzed using Wilcoxon signed-rank and logistic regression tests. The potential molecular mechanism associated with SERPINE1 expression in gastric cancer were confirmed using gene set enrichment analysis (GSEA).

RESULTS

The TCGA data showed that SERPINE1 was overexpressed in tumor tissues compared to normal mucosae and associated with the tumor T stage and pathological grade. SERPINE1 overexpression was associated with the poor overall survival (OS) of patients. The findings were confirmed with 136 patients, that is, SERPINE1 expression was associated with poor OS (hazard ratio (HR): 1.82; 95% confidence interval (CI): 0.84-1.83; p = 0.012)) as an independent predictor (HR: 2.11, 95% CI: 0.81-2.34; p = 0.009). The resulting data were further processed by GSEA showed that SERPINE1 overexpression was associated with the activation of EPITHELIAL_MESENCHYMAL_TRANSITION, TNFA_SIGNALING_VIA_NFKB, INFLAMMATORY_RESPONSE, ANGIOGENESIS, and HYPOXIA.

CONCLUSIONS

SERPINE1 overexpression is associated with a poor gastric cancer prognosis.

Identification and validation of a T cell marker gene-based signature to predict prognosis and immunotherapy response in gastric cancer

Although the role of T cells in tumor immunity and modulation of the tumor microenvironment (TME) has been extensively studied, their precise involvement in gastric adenocarcinoma remains inadequately explored. In this work, we analyzed the single-cell RNA sequencing data set in GSE183904 and identified 322 T cell marker genes using the "FindAllMarkers" method of the R package "Seurat". STAD patients in the TCGA database were divided into high-risk and low-risk categories based on risk scores. The five-gene prediction signature based on T cell marker genes can predict the prognosis of gastric cancer patients with high accuracy. In the training cohort, the areas under the receiver operating characteristic (ROC) curve were 0.667, 0.73, and 0.818 at 1, 3, and 5 years. External validation of the predictive signature was also performed using multiple clinical subgroups and GEO cohorts. To help with practical application, a diagnostic model was created that shows values of 0.732, 0.752, and 0.816 for the relevant areas under the ROC curve at 1, 3, and 5 years. The T cell marker genes identified in this study may serve as potential therapeutic targets, and the developed predictive signatures and nomograms may aid in the clinical management of gastric cancer.

Matrix metalloproteinase‑1 expression is regulated by HIF‑1‑dependent and epigenetic mechanisms and serves a tumor‑suppressive role in gastric cancer progression

The matrix metalloproteinase (MMP) family is associated with degradation of the extracellular matrix and is known to promote cancer invasion. The present study aimed to investigate the biological role of MMP-1 in gastric cancer cells and analyze the association between MMP-1 expression and the clinical outcomes of gastric cancer patients. In the present study, hypoxia accelerated invasion, accompanied by elevated MMP-1 expression in the gastric cancer cell line 58As9. Additionally, hypoxia-inducible factor-1α (HIF-1α) knock- down in 58As9 cells reduced MMP-1 expression under hypoxic conditions. Treatment with 5-aza-2-deoxycytidine and trichostatin A restored MMP-1 expression in the MMP-1-deficient cell lines MKN45 and MKN74. These results indicated that MMP-1 expression was controlled by both HIF-1α-dependent and epigenetic mechanisms in gastric cancer cell lines. In addition, MMP-1 knockdown impaired the hypoxia-induced invasiveness of 58As9 cells, implicating MMP-1 in the elevated invasion. By contrast, knockdown enhanced the proliferative ability of 58As9 cells, whereby expression of cell cycle-related genes was subsequently altered. In nude mouse models, the knockdown accelerated the growth of xenograft tumor and the development of peritoneal dissemination. In an immunohistochemical study using 161 surgically resected cancer tissues, the Ki67 score was significantly higher in the group with low MMP-1 expression (P<0.001). Disease-free survival (DFS) and disease-specific survival (DSS) were both significantly reduced in patients with low MMP-1 expression (log-rank test; DFS: P=0.005; DSS: P=0.022). Multivariate analysis demonstrated that MMP-1 expression was an independent prognostic factor for DFS and DSS [DFS: HR=2.11 (1.22–3.92) P=0.005, DSS: HR=2.90 (1.23–8.50) P=0.012]. In conclusion, the present study indicated that MMP-1 may serve as a tumor-suppressive factor that inhibits gastric cancer progression, although it promoted invasion in vitro.

Emerging therapeutic targets for gastric cancer from a host-Helicobacter pylori interaction perspective

INTRODUCTION

Gastric cancer (GC) has the higher genetic, cytologic, and architectural heterogeneity compared to other gastrointestinal cancers. By inducing gastric inflammation, Helicobacter pylori (HP) may lead to GC through combining bacterial factors with host factors. In this regard, identification of the major therapeutic targets against the host-HP interactions plays a critical role in GC prevention, diagnosis, and treatment.

AREAS COVERED

This study offers new insights into the promising therapeutic targets against the angiogenesis, invasion, or metastasis of GC from a host-HP interaction perspective. To this end, MEDLINE, EMBASE, LILACS, AIM, and IndMed databases were searched for relevant articles since 1992.

EXPERT OPINION

Wnt signaling and COX pathway have a well-documented history in the genesis of GC by HP and might be considered as the most promising targets for early GC treatment. Destroying HP may decrease the risk of GC, but it cannot fully hinder the GC development induced by HP infection. Therefore, targeting HP-activated pathways, especially COX-2/Wnt/beta-catenin/VEGF, TLR2/TLR9/COX-2, COX2-PGE2, and NF-κB/COX-2, as well as EPHA2, MMPs, and miR-543/SIRT1 axis, can be an effective measure in the early treatment of GC. However, different clinical trials and large, multi-center cohorts are required to validate these potentially effective targets for GC therapy.

Tanshinone II-A Inhibits Invasion and Metastasis of Human Hepatocellular Carcinoma Cells in Vitro and in Vivo

Aims and Background

Tanshinone II-A is an alcohol extract of the root of the traditional Chinese medicinal plant Salvia miltiorrhiza Bunge, whose effects and mechanism in tumor metastasis are still unclear. The aim of this study was to investigate the effects of tanshinone II-A on tumor invasion and metastasis in human hepatocellular carcinoma (HCC) and its possible mechanism of action.

Methods and Study Design

The HCC cell lines HepG2 and SMMC-7721 were treated with tanshinone II-A at different doses. Invasion and metastasis of tumor cells were examined by in vitro and in vivo assays. The molecular mechanisms of tanshinone II-A for inhibiting invasion and metastasis of HCC cells were investigated by Western blot and gelatin zymography.

Results

Treatment with tanshinone II-A had inhibitory effects on the migration and invasion of HCC cells. Increasing doses resulted in enhanced inhibitory effects. At 0.5 mg/L, the inhibitory effect was noticeable. At 1 mg/L, the inhibitory rate was 53.15%. The inhibitory effect became stronger with time; among 24, 48, 72 and 96 hours of treatment, the most significant effects were observed at 72 hours. Tanshinone II-A also significantly inhibited in vivo metastasis of HepG2 cells. Tanshinone II-A inhibited in vitro and in vivo invasion and metastasis of HCC cells by reducing the expression of the metalloproteinases MMP2 and MMP9 and by blocking NF-kappa B activation.

Conclusions

Tanshinone II-A effectively inhibited invasion and metastasis of HCC cells in vitro and in vivo, partly by inhibiting the activity of MMP2 and MMP9, and partly via the NF-kappa B signal transduction pathway.

Is the Urokinase-type Plasminogen Activator System a Reliable Prognostic Factor in Gastric Cancer?

Aim

The aim of this prospective study was to evaluate the clinical and prognostic impact of immunohisto-chemically assessed uPA and PAI-1 in patients with gastric cancer.

Methods

This prospective study analyzed specimens obtained from 105 gastric cancer patients who underwent gastrectomy with extended lymphadenectomy. The immunohistochemical expression of uPA and PAI-1 was studied semiquantitatively in the tumor epithelium and was correlated with the clinicopathological features of each patient.

Results

Univariate analysis revealed no statistically significant association of uPA levels with pT and pN category (p=0.655 and 0.053, respectively), grading (p=0.374), depth of tumor invasion (p=0.665), UICC classification (p=0.21) and the Laurén classification (p=0.578). PAI-1 expression showed no statistically significant correlation with pT, pN and M category (p=0.589, 0.414, and 0.167, respectively), grading (p=0.273), and the Laurén classification (p=0.368). Only the UICC classification was significantly correlated with PAI-1 (p=0.016). Kaplan-Meier analysis revealed no significant association of uPA and PAI-1 with overall survival (p=0.0929 and 0.0870, respectively).

Conclusions

Our results could not verify any prognostic value of uPA and PAI-1 levels in patients with gastric carcinoma. Therefore, the uPA-system as a biologically defined prognostic marker to identify high-risk gastric cancers should be applied with caution. However, considering the number of patients involved and the borderline level of significance observed in this study, a larger number of events may have resulted in significant differences.

The urokinase plasminogen activation system in gastroesophageal cancer: A systematic review and meta-analysis

Background

The urokinase plasminogen activation (uPA) system is a crucial pathway for tumour invasion and establishment of metastasis. Although there is good evidence that uPA system expression is a clinically relevant biomarker in some solid tumours, its role in gastroesophageal cancer is uncertain.

Results

We identified 22 studies encompassing 1966 patients which fulfilled the inclusion criteria. uPA, uPAR, or PAI-1 expression is significantly associated with high risk clinicopathological features. High uPA expression is associated with a shorter RFS (HR 1.90 95% 1.16–3.11, p = 0.01) and OS (HR 2.21 95% CI 1.74–2.80, p < 0.0001). High uPAR expression is associated with poorer OS (HR 2.21 95%CI 1.82–2.69, p < 0.0001). High PAI-1 expression is associated with shorter RFS (HR 1.96 96% CI 1.07–3.58, p = 0.03) and OS (HR 1.84 95%CI 1.28–2.64, p < 0.0001). There was no significant association between PAI-2 expression and OS (HR 0.97 95%CI 0.48–1.94, p < 0.92) although data was limited.

Materials and Methods

We undertook a systematic review evaluating expression of uPA, urokinase plasminogen activator receptor (uPAR), plasminogen activator inhibitor-1 (PAI-1/SerpinE1) and plasminogen activator inhibitor-2 (PAI-2/SerpinB2) on primary oesophageal, gastro-oesophageal junction, and gastric adenocarcinomas. We performed a meta-analysis of clinicopathological associations, overall survival (OS) and recurrence free survival (RFS).

Conclusions

We conclude that the uPA system is a clinically relevant biomarker in primary gastroesophageal cancer, with higher expression of uPA, uPAR and PAI-1 associated with higher risk disease and poorer prognosis. This also highlights the potential utility of the uPA system as a therapeutic target for improved treatment strategies.

Prostaglandin E2 stimulates urokinase-type plasminogen activator receptor via EP2 receptor-dependent signaling pathways in human AGS gastric cancer cells

Aberrant expression of urokinase-type plasminogen activator receptor (uPAR) has been observed in human gastric cancers. Prostaglandin E₂ (PGE₂ ), whose biosynthesis is catalyzed by cyclooxygenase-2 (COX-2), is implicated in cancer metastasis; however, the cellular and molecular mechanisms of PGE₂ -driven uPAR expression are yet to be elucidated in human gastric cancer AGS cells. In this study, we showed that PGE₂ induces uPAR expression in concentration- and time-dependent manners. Furthermore, using antagonists and siRNA, we found that among the four subtypes of PGE₂ receptors, EP2 receptors are involved in PGE₂ -induced uPAR expression. PGE₂ induced the activation of Src, epidermal growth factor receptor (EGFR), c-Jun NH₂ -terminal kinase (JNK), extracellular signal-regulated kinase (Erk), and p38 mitogen activated protein kinase (p38 MAPK). Specific inhibitor and mutagenesis studies showed that Src, EGFR, JNK1/2, and Erk1/2 are involved in PGE₂ -induced uPAR expression. PGE₂ induces EP2-dependent phosphorylation of Src, while the activation of Src-dependent EGFR leads to the phosphorylation of JNK1/2 and Erk1/2. Deletion and site-directed mutagenesis studies demonstrated the involvement of transcription factor activator protein (AP)-1 and nuclear factor-kappa B (NF-κB) in PGE₂ -induced uPAR expression. EGFR-dependent MAPKs (JNK1/2 and Erk1/2) function as the upstream signaling molecules in the activation of AP-1 and NF-κB, respectively. AGS cells pre-treated with PGE₂ showed remarkably enhanced invasiveness, which was partially abrogated by uPAR-neutralizing antibodies. To the best of our knowledge, this is the first report that PGE₂ -induced uPAR expression, which stimulates invasiveness of human gastric cancer AGS cells, is mediated by the EP2 receptor-dependent Src/EGFR/JNK1/2, Erk1/2/AP-1, and Src/EGFR/JNK1/2, Erk1/2/NF-κB cascades. © 2016 Wiley Periodicals, Inc.

Components of the Plasminogen-Plasmin System as Biologic Markers for Cancer

Members of the plasminogen-plasmin (PP) system participate in many physiologic functions. In particular, uPA, its receptor (uPAR) and its inhibitor PAI-1 play an important role in cell migration, cell proliferation and tissue remodeling. Through a number of interactions, these components of the PP system are also involved in the pathogenesis of many diseases. In cancer, they modulate the essential processes of tumor development, growth, invasion and metastasis as well as angiogenesis and fibrosis. Thus, quantification of uPA, uPAR and PAI-1 in tumors and, in some cases in the circulating blood, became of potential value in the prognostication of many types of cancer. These include cancer of the breast, stomach, colon and rectum, esophagus, pancreas, glioma, lung, kidney, prostate, uterine cervix, ovary, liver and bone. Published data are reviewed in this chapter. Clinical validation of the prognostic value has also been made, particularly in cancer of the breast. Inclusion of these biomarkers in the risk assessment of cancer patients is now considered in the risk-adapted management in carcinoma of the breast. Factors limiting its broader use are discussed with suggestions how these can be overcome. Hopefully the use of these biomarkers will be applied to other types of cancer in the near future.

A polysaccharide from mushroom Huaier retards human hepatocellular carcinoma growth, angiogenesis, and metastasis in nude mice

Mushroom Huaier has become a focus of interest in the treatment of hepatocellular carcinoma (HCC). Presently, we isolated and purified one polysaccharide from this mushroom. This study aimed to investigate the effects of SP1 on tumor growth and metastasis in a HCC xenograft model and explore its possible mechanism of action. Our results showed that SP1 not only significantly inhibited the proliferation of SMMC-7721 cells in vitro at the concentration ranging from 0 to 800 μg/ml but also suppressed the HCC tumor growth and metastatic nodules to the lung in SMMC-7721-bearing mice by oral administration at three doses of 30, 60, and 120 mg/kg. Concomitantly, immunohistochemistry analysis of tumor tissues identified that SP1 administration at three doses significantly inhibited the in vivo cancer cell proliferation and microvessel density (MVD) formation, evidenced by a low proliferating cell nuclear antigen (PCNA) and CD34 expression, but increased the percentage of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells. Keeping in line with this observation, SP1 treatment decreased serum matrix metalloproteinase (MMP) 2 and vascular endothelial growth factor (VEGF) levels, downregulated the protein expression of hypoxia-inducible factor (HIF)-1alpha, VEGF, MMP2, bcl-2, N-cadherin, signal transducer and activator of transcription 3 (STAT3), and metadherin (MTDH), and upregulated bax and NE-cadherin protein expression in tumor tissues. Taken together, our data suggest that SP1 appears to be a promising chemopreventive agent for the tumorigenesis and metastasis in patients with HCC, especially at advanced stages.

Induction of brain microvascular endothelial cell urokinase expression by Cryptococcus neoformans facilitates blood-brain barrier invasion

The invasive ability of the blood-borne fungal pathogen Cryptococcus neoformans can be enhanced through interactions with host plasma components, such as plasminogen. Previously we showed by in vitro studies that plasminogen coats the surface of C. neoformans and is converted to the active serine protease, plasmin, by host plasminogen activators. Viable, but not formaldehyde- or sodium azide-killed, cryptococcal strains undergo brain microvascular endothelial cell-dependent plasminogen-to-plasmin activation, which results in enhanced, plasmin-dependent cryptococcal invasion of primary bovine brain microvascular endothelial cells and fungal ability to degrade plasmin substrates. In the present work, brain microvascular endothelial cells cultured with viable, but not killed, cryptococcal strains led to significant increases in both urokinase mRNA transcription and cell-associated urokinase protein expression. Soluble urokinase was also detected in conditioned medium from brain microvascular endothelial cells cultured with viable, but not killed, C. neoformans. Exposure of plasminogen pre-coated viable C. neoformans to conditioned medium from strain-matched brain microvascular endothelial cell-fungal co-cultures resulted in plasminogen-to-plasmin activation and plasmin-dependent cryptococcal invasion. siRNA-mediated silencing of urokinase gene expression or the use of specific inhibitors of urokinase activity abrogated both plasminogen-to-plasmin activation on C. neoformans and cryptococcal-brain microvascular endothelial cell invasion. Our results suggest that pathogen exploitation of the host urokinase-plasmin(ogen) system may contribute to C. neoformans virulence during invasive cryptococcosis.

Ardipusilloside inhibits survival, invasion and metastasis of human hepatocellular carcinoma cells

ETHNOPHARMACOLOGICAL RELEVANCE

Ardipusilloside I is a triterpene-saponin isolated from the Traditional Chinese Medicine Ardisia pusilla A. DC. Its effects and mechanism on invasion and metastasis of liver cancer cells are unclear.

MATERIALS AND METHODS

The human hepatocellular carcinoma cell line HepG2 and SMMC-7721 cells were treated with different doses of Ardipusilloside I. Cellular survival, in vitro migration and invasion were evaluated. In vivo metastatic abilities of the HCC cells were detected. We further investigated expression and phosphorylation of Mek, Erk and Akt by using Western blot. MMP2 and MMP9 activities were evaluated by gelatin zymography. E-cadherin expression, Rac1 and Cdc42 activities were examined by Western blot and pull-down assay.

RESULTS

Ardipusilloside I inhibited invasion and metastasis of HCC cells both in vitro and in vivo by reducing the protein expressions of metalloproteinase (MMP)-9 and MMP2 proteins. Ardipusilloside I activated Rac1 that enhanced E-cadherin activity and resulted in significantly less metastasis.

CONCLUSION

Our findings indicate that Ardipusilloside I has the potential of inhibition of liver cancer survival, invasion and metastasis both in vitro and in vivo.

RUNX3 mediates suppression of tumor growth and metastasis of human CCRCC by regulating cyclin related proteins and TIMP-1

Here we presented that the expression of RUNX3 was significantly decreased in 75 cases of clear cell renal cell carcinoma (CCRCC) tissues (p<0.05). Enforced RUNX3 expression mediated 786-O cells to exhibit inhibition of growth, G1 cell-cycle arrest and metastasis in vitro, and to lost tumorigenicity in nude mouse model in vivo. RUNX3-induced growth suppression was found partially to regulate various proteins, including inhibition of cyclinD1, cyclinE, cdk2, cdk4 and p-Rb, but increase of p27^Kip1, Rb and TIMP-1. Therefore, RUNX3 had the function of inhibiting the proliferative and metastatic abilities of CCRCC cells by regulating cyclins and TIMP1.

Gastric cancer: basic aspects

Gastric cancer (GC) is a world health burden, ranging as the second cause of cancer death worldwide. Etiologically, GC arises not only from the combined effects of environmental factors and susceptible genetic variants but also from the accumulation of genetic and epigenetic alterations. In the last years, molecular oncobiology studies brought to light a number of genes that are implicated in gastric carcinogenesis. This review is intended to focus on the recently described basic aspects that play key roles in the process of gastric carcinogenesis. Genetic variants of the genes IL-10, IL-17, MUC1, MUC6, DNMT3B, SMAD4, and SERPINE1 have been reported to modify the risk of developing GC. Several genes have been newly associated with gastric carcinogenesis, both through oncogenic activation (GSK3β, CD133, DSC2, P-Cadherin, CDH17, CD168, CD44, metalloproteinases MMP7 and MMP11, and a subset of miRNAs) and through tumor suppressor gene inactivation mechanisms (TFF1, PDX1, BCL2L10, XRCC, psiTPTE-HERV, HAI-2, GRIK2, and RUNX3). It also addressed the role of the inflammatory mediator cyclooxygenase-2 (COX-2) in the process of gastric carcinogenesis and its importance as a potential molecular target for therapy.

Clinical utility of level-of-evidence-1 disease forecast cancer biomarkers uPA and its inhibitor PAI-1

The prognostic and/or predictive value of the cancer biomarkers, urokinase-type plasminogen activator (uPA) and its inhibitor (plasminogen activator inhibitor [PAI]-1), determined by ELISA in tumor-tissue extracts, was demonstrated for several cancer types in numerous clinically relevant retrospective or prospective studies, including a multicenter breast cancer therapy trial (Chemo-N0). Consequently, for the first time ever for any cancer biomarker for breast cancer, uPA and PAI-1 have reached the highest level of evidence, level-of-evidence-1. At present, two other breast cancer therapy trials, NNBC-3 and Plan B, also incorporating uPA and PAI-1 as treatment-assignment tools are in effect. Furthermore, small synthetic molecules targeting uPA are currently in Phase II clinical trials in patients afflicted with advanced cancer of the ovary, breast or pancreas.

Artemisinin inhibits in vitro and in vivo invasion and metastasis of human hepatocellular carcinoma cells

Artemisinin (ART) is isolated from the medicinal plant Artemisia annua L. To determine its effects on the invasion and metastasis of tumors, the human hepatocellular carcinoma (HCC) cell lines HepG2 and SMMC-7721 were treated with different concentrations of ART. Starting at 12.5μM, ART had inhibitory effects in migration and invasion assays that increased at higher concentrations. The inhibitory effect also became stronger with time, from 24 to 72h. ART significantly inhibited the in vivo metastatic abilities of the HepG2 HCC cell line. ART inhibited the invasion and metastasis of HCC cells both in vitro and in vivo by reducing the level of the MMP2 metalloproteinase, and by inducing the TIMP2 protein. ART activated Cdc42, which enhanced E-cadherin activity, resulting in greater cell-cell adhesion, and significantly reduced metastasis.

MSP-induced RON activation upregulates uPAR expression and cell invasiveness via MAPK, AP-1 and NF-κB signals in gastric cancer cells

Overexpression of recepteur d'Origine nantais (RON) and urokinase plasminogen activator receptor (uPAR) have been observed in human gastric cancers. However, the interaction between RON and uPAR in gastric cancer is unclear. The present study investigated the effect of macrophage-stimulating protein (MSP, the RON ligand) on uPAR expression and the underlying signal pathways in human gastric cancer AGS cells. uPAR messenger RNA expression was induced by MSP in a time- and concentration-dependent manner. MSP also induced uPAR promoter activity. The introduction of RON-specific small interfering RNA (siRNA) significantly affected the MSP-induced uPAR transcription. Deleted and site-directed mutagenesis studies demonstrated the involvement of the binding sites of transcription factor nuclear factor-kappaB (NF-κB) and activator protein (AP)-1 in the MSP-induced uPAR expression. Studies with expression vectors encoding mutated-type NF-κB signaling molecules and AP-1 decoy confirmed that NF-κB and AP-1 were essential for the MSP-induced uPAR expression. In addition, MSP induced the activation of extracellular signal-regulated kinase-1/2 (Erk-1/2), c-Jun amino terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). Dominant-negative mutants (K97M and TAM67) and specific inhibitors of Erk-1/2 and JNK were able to suppress the MSP-induced uPAR expression. AGS cells pretreated with MSP showed a remarkably enhanced invasiveness, which was partially abrogated by siRNA-targeted RON and uPAR-neutralizing antibodies. The above results suggest that MSP induces uPAR expression via MAPK, AP-1 and NF-κB signaling pathways and, in turn, stimulates cell invasiveness in human gastric cancer AGS cells.

SERPINE1 intron polymorphisms affecting gene expression are associated with diffuse-type gastric cancer susceptibility

BACKGROUND

A primary inhibitor of plasminogen activators, SERPINE1 (serpin peptidase inhibitor 1, clade E, member 1, also known as plasminogen activator inhibitor type 1), is an important regulator in tumorigenesis and is highly expressed in many cancers.

METHODS

Five tag single nucleotide polymorphisms (SNPs) and 1 insertion polymorphism within SERPINE1 were genotyped in 1101 unrelated Korean individuals (a case group of 612 patients with gastric cancer and a control group of 489 healthy individuals). Associations with susceptibility to diffuse-type gastric cancer (DGC) and intestinal-type gastric cancer were assessed using multivariate logistic regression analyses adjusted for age and sex. Allelic differences in the contribution to gene expression were measured using luciferase assays.

RESULTS

SNP c.1162+162C>T (rs2227692) in intron 7 was associated with susceptibility to DGC but not with susceptibility to intestinal-type gastric cancer. The minor allele-carrying genotypes C/T and T/T had 1.6-fold greater odds of DGC than the C/C genotype (P = .00084). This SNP was linked to a repeat-number variation c.1162+604AAAG(11_17), a deletion (del) variation c.1162+664_1162+673del, and another SNP c.1162+859T>A (rs2070683) in intron 7 based on the sequencing of 5 patients and 5 controls. The risk haplotype of the 4 variations exhibited a 30% greater gene expression level than the nonrisk haplotype in luciferase reporter assays (P = .025). In contrast, DGC susceptibility was not associated with the c.-1969_-1968insG polymorphism (rs1799768) in the promoter, commonly known as 4G/5G, in which the minor 5G allele is less active in transcription than the major 4G allele.

CONCLUSIONS

An association between SERPINE1 and DGC susceptibility was observed with 4 correlated polymorphisms in intron 7 rather than the 4G/5G polymorphism in the promoter, although all polymorphisms affected gene expression.

Upregulation of the GRIM-19 gene suppresses invasion and metastasis of human gastric cancer SGC-7901 cell line

Gene associated with retinoid-IFN-induced mortality 19 (GRIM-19), as a novel IFN-beta/RA-inducible gene product, was identified as a potential tumor suppressor associated with growth inhibition and cell apoptosis. Recently, it has been reported that the apoptotic effects and apoptosis-related gene induction of GRIM-19 can be attenuated by GW112, indicating that GRIM-19 and GW112 are involved in a common signal transduction pathway. To investigate the signaling mechanisms that link GRIM-19 to GW112 and their functional role in tumor cell invasion and metastasis, we utilized adenovirus-mediated overexpression of GRIM-19 in the gastric cancer SGC-7901 cell line. We observed that enhanced expression of GRIM-19 not only downregulated GW112 but also decreased NF-small ka, CyrillicB binding activity. As a result, we found that tumor cell adhesion, migration, invasion and liver metastasis were inhibited. Additionally, upregulation of GRIM-19 also suppressed secretion of urokinase-type plasminogen activator (u-PA), matrix metalloproteinase (MMP)-2, 9 and vascular endothelial growth factor (VEGF). These results indicate that GRIM-19 acts as an upstream regulator of GW112 to block NF-small ka, CyrillicB binding activity, thereby inhibiting gastric cancer cell migration, invasion and metastasis. We conclude that adenoviral transfer of the GRIM-19 gene may be an efficacious approach to controlling the invasion and metastasis of human gastric cancer.

A pilot study of urokinase-type plasminogen activator (uPA) overexpression in the brush cytology of patients with malignant pancreatic or biliary strictures

We have previously demonstrated that uPA is overexpressed in pancreatic tumors. In an attempt to diagnose these tumors earlier, we sought to determine whether uPA could be identified in endoscopic retrograde cholangiopancreatography obtained brushings in patients with malignant pancreatic and biliary strictures. Secondarily, uPA was measured in the serum of this patient population. uPA overexpression was identified in the cytologic tissue in 8 of 11 patients (72.7%). Serum analysis demonstrated a 2-fold higher concentration of uPA in the pancreaticobiliary cancer patients (1.27 versus 0.56 ng/mL; P = .0182). Also, uPA overexpression correlated with serum levels (P < .0001). This study confirms that uPA can be detected in the ERCP cytologically obtained tissue and is frequently present in a higher concentration in the serum of pancreaticobiliary cancer patients. A larger sample size will be required to address its value as a sensitive marker for the diagnosis of pancreatic or biliary cancers.

Inhibitory effects of tanshinone II-A on invasion and metastasis of human colon carcinoma cells

AIM

To investigate the effects and possible mechanisms of tanshinone II-A, an alcohol extract of the root of Salvia miltiorrhiza Bunge, on tumor invasion and metastasis of human colon carcinoma (CRC) cells.

METHODS

The effects of tanshinone II-A on invasion and metastasis of CRC cell lines HT29 and SW480 were evaluated by in vitro and in vivo assays. Western blotting was used to investigate possible molecular mechanisms of tanshinone II-A anti-cancer actions.

RESULTS

Tanshinone II-A inhibited migration and invasion of CRC cells in a dose-dependent manner. The inhibitory effect also depended on time, with the most significant effects observed at 72 h. Tanshinone II-A also significantly inhibited in vivo metastasis of colon carcinoma SW480 cells. It inhibited in vitro and in vivo invasion and metastasis of CRC cells by reducing levels of urokinase plasminogen activator (uPA) and matrix metalloproteinases (MMP)-2 and MMP-9, and by increasing levels of tissue inhibitor of matrix metalloproteinase protein (TIMP)-1 and TIMP-2. Tanshinone II-A was also shown to suppress the nuclear factor-kappaB (NF-kappaB) signal.

CONCLUSION

Tanshinone II-A inhibited in vitro and in vivo invasion and metastasis of CRC cells. The effect resulted from changes in the levels of uPA, MMP-2, MMP-9, TIMP-1 and TIMP-2, and apparent inhibition of the NF-kappaB signal transduction pathway.

Obesity and breast cancer: the roles of peroxisome proliferator-activated receptor-γ and plasminogen activator inhibitor-1

Breast cancer is the most prominent cancer among females in the United States. There are a number of risk factors associated with development of breast cancer, including consumption of a high-fat diet and obesity. Plasminogen activator inhibitor-1 (PAI-1) is a cytokine upregulated in obesity whose expression is correlated with a poor prognosis in breast cancer. As a key mediator of adipogenesis and regulator of adipokine production, peroxisome proliferator-activated receptor-γ (PPAR-γ) is involved in PAI-1 expression from adipose tissue. We summarize the current knowledge linking PPAR-γ and PAI-1 expression to high-fat diet and obesity in the risk of breast cancer.

The role of plasminogen-plasmin system in cancer

Components of the plasminogen-plasmin system participate in a wide variety of physiologic and pathologic processes, including tumor growth, invasion and metastasis, through their effect on angiogenesis and cell migration. These components are found in most tumors and their expression not only signifies their function but also carries a prognostic value. Their expression is in turn modulated by cytokines and growth factors, many of which are up-regulated in cancer. Though both tPA and uPA are expressed in tumor cells, uPA with its receptor (uPAR) is mostly involved in cellular functions, while tPA with its receptor Annexin II on endothelial surface, regulates intravascular fibrin deposition. Among the inhibitors of fibrinolysis, PAI-1 is a major player in the pathogenesis of many vascular diseases as well as in cancer. Therapeutic interventions, either using plasminogen activators or experimental inhibitor agents against PAI-1, have shown encouraging results in experimental tumors but not been verified clinically.

The effects of cyclooxygenase2-prostaglandinE2 pathway on Helicobacter pylori-induced urokinase-type plasminogen activator system in the gastric cancer cells

BACKGROUND

Urokinase-type plasminogen activator (uPA) and its receptor (uPAR) play an important role in the destruction of the extracellular matrix and basement membrane. The induction of uPA and uPAR in the gastric cancer cells with H. pylori has been demonstrated previously. The involvement of COX-2-PGE2 pathway in the uPA system (uPA and uPAR) expression is unclear.

METHODS

Gastric cancer cells (MKN45) were co-cultured with H. pylori standard strain (NCTC11637). The specific inductions of uPA and uPAR mRNA were examined by reverse transcription-polymerase chain reaction amplification. The secreted uPA antigen was measured by ELISA. To evaluate the involvement of COX-2 and PGE2 pathway in H. pylori-induced uPA and uPAR expressions, we examined the effects of COX-2 inhibitor and PGE2 receptor antagonist on H. pylori-induced uPA and uPAR expression in the gastric cancer cells.

RESULTS

The expressions of both uPA and uPAR mRNAs in the gastric cancer cells increased obviously (12-fold and 3-fold, respectively) with H. pylori stimulation. The amount of uPA antigen into the culture medium increased dramatically with H. pylori stimulation. The COX-2 expression level in the gastric cancer cells increased remarkably with H. pylori stimulation. H. pylori-induced uPA and uPAR expression levels were suppressed with COX2 inhibitor treatment. The amount of PGE2 antigen into the culture medium increased dramatically 24 hours after H. pylori stimulation. The gastric cancer cells expressed EP2 and EP4 subtypes. EP2 receptor antagonist suppressed the H. pylori-induced uPA and uPAR expressions in the gastric cancer cells.

CONCLUSIONS

Our results indicated that COX2-PGE2 pathway may be involved in H. pylori-associated uPA and uPAR induction, and that COX-2 inhibitor or EP2 receptor antagonist may inhibit angiogenesis and tumor invasion via suppression of the uPA system.

p75 Neurotrophin Receptor Inhibits Invasion and Metastasis of Gastric Cancer

The p75 neurotrophin receptor (p75NTR) is a focus for study at present. However, its function in gastric cancer was not elucidated. Here, we investigated its relation with metastasis of gastric cancer. By immunohistochemistry, we found that the positive rate of p75NTR expression in metastatic gastric cancer was 15.09% (16 of 106), which was lower compared with nonmetastatic gastric cancer (64.15%; 68 of 106). The average staining score in nonmetastatic gastric cancer was significantly higher than in metastatic gastric cancer (1.21 +/- 0.35 versus 0.23 +/- 0.18; P<0.01). p75NTR protein level was also lowly expressed in the highly liver-metastatic gastric cancer cell line XGC9811-L compared with other gastric cancer cell lines by Western blotting. It could also significantly inhibit the in vitro adhesive, invasive, and migratory and in vivo metastatic abilities of gastric cancer cell lines SGC7901 and MKN45 by reducing urokinase-type plasminogen activator (uPA) and matrix metalloproteinase (MMP)-9 proteins and by increasing tissue inhibitor of matrix metalloproteinase (TIMP)-1 protein. Further studies showed that p75NTR could suppress the nuclear factor-kappaB (NF-kappaB) signal. SN50, a specific inhibitor of NF-kappaB, which could inhibit in vitro invasive and migratory abilities of gastric cancer cells, reduced expression of uPA and MMP9 proteins and increased expression of TIMP1 protein. Taken together, p75NTR had the function of inhibiting the invasive and metastatic abilities of gastric cancer cells, which was mediated, at least partially, by down-regulation of uPA and MMP9 proteins and up-regulation of TIMP1 protein via the NF-kappaB signal transduction pathway. Our studies suggested that p75NTR may be used as a new potential therapeutic target in metastatic gastric cancer.

Urokinase-type plasminogen activator and its inhibitor in thyroid neoplasms: a cytosol study

PURPOSE

Higher levels of urokinase-type plasminogen activator (uPA) and its inhibitor (PAI-1) are linked to the poor prognosis in a variety of malignances. uPA and PAI-1 were expressed in most thyroid carcinomas, as had been measured immunohistochemically. However, no relationship between their expression and clinicopathological parameters were found. Aim of the present study was to investigate the expression and clinical relevance of uPA and PAI-1 in thyroid cancer.

PATIENTS AND METHODS

uPA and PAI-1 in paired cytosol samples of thyroid tumor and normal tissue were determined in 23 patients using enzyme-linked immunosorbent assay and correlated to the known prognostic features.

RESULTS

Both uPA and PAI-1 concentrations were significantly higher in malignant thyroid tumors (uPA=1.342 +/- 2.944 and PAI-1=17.615 +/- 31.933 ng/mg protein) than in normal tissue (uPA=0.002 +/- 0.009, P=0.011 and PAI-1=2.333 +/- 0.338 ng/mg protein, P=0.001) with positive correlation of the two proteins in the tumors. There were no differences in proteins' levels between benign tumors and normal tissue. Both proteins' concentrations were significantly different among various histological grades (uPA P=0.024 and PAI-1 P=0.017), showing higher values in higher tumor grades (grade I uPA=0.116 +/- 0.247 and PAI-1=4.802 +/- 4.151 ng/mg protein; grade III uPA=8.45 +/- 2.192 and PAI-1=94.65 +/- 59.468 ng/mg protein). The uPA and PAI-1 levels showed significant differences among different histological types of thyroid cancer (uPA P=0.049 and PAI-1=0.017). The lowest values were in adenomas (uPA=0.013 +/- 0.025 and PAI-1=2.785 +/- 1.069 ng/mg protein) and the highest in anaplastic carcinomas (uPA=8.45 +/- 2.192 and PAI-1=94.65 +/- 59.468 ng/mg protein). uPA and PAI-1 were significantly higher in anaplastic vs. well-differentiated cancers (uPA P=0.014 and PAI-1 P=0.026), if extrathyroidal invasion (uPA P=0.019 and PAI-1 P=0.009) or distant metastases (uPA P=0.006 and PAI-1 P=0.003) had been present, and in tumors whose size exceeded 1 cm in diameter (uPA P=0.009 and PAI-1 P=0.035). Only PAI-1, but not uPA was significantly higher in multicentric vs. solitary tumors (P=0.012) and lymph node positive compared to lymph node negative patients (P=0.042). The differences of uPA and PAI-1 did not reach the significant level when patients with well-differentiated tumors below and above 40 years of age had been compared. Survival analysis revealed the significant impact of both uPA and PAI-1 on the Progression-Free Survival (PFS) (38.84 vs. 3.67 months for patients with low and high uPA, respectively, P<0.001; 38.2 vs. 12 months for patients with low and high PAI-1, respectively, P=0.016).

CONCLUSIONS

The correlation of high uPA and PAI-1 with the known prognostic factors of poorer outcome and with lower PFS rate in patients with thyroid cancers proved that these proteins could be an additional prognostic parameter.

Tissue-type plasminogen activator activity in morphologically normal tissues adjacent to gastrointestinal carcinomas is associated with the degree of tumor progression

PURPOSE

To investigate whether the level of plasminogen activator (PA) activity assayed in gastrointestinal carcinomas and the "morphologically normal tissues" adjacent to them is associated with the degree of tumor progression.

METHODS

Tumor and "normal tissues" were obtained from gastrointestinal surgical samples to assess urokinase-type (u-PA) and tissue-type plasminogen activator (t-PA) activities by radial caseinolytic assay and the expression of PA inhibitor-1 (PAI-1) by ELISA. We compared the PA system between the tumor and "normal tissues" and we investigated the existence of correlations between: (a) PA production in the tumor and "normal tissues", (b) different components of the PA system, and (c) PA system and the degree of tumor progression.

RESULTS

(1) Total PA activity, u-PA activity and PAI-1 expression are significantly higher in tumor than in "normal tissues", whereas t-PA activity does not differ between them. (2) Total PA activity mainly correlates with u-PA activity in tumor tissues and similarly with u-PA and t-PA activities in "normal tissues". (3) There is a significant association between t-PA activity in tumor and "normal tissues" and the degree of tumor progression.

CONCLUSIONS

"Morphologically normal tissues" adjacent to carcinomas present abnormal t-PA activity that is associated with the degree of tumor progression. Assaying of this activity could be useful as a predictive parameter.

Plasminogen activator inhibitor-1 as a potential marker for the malignancy of colorectal cancer

To test the hypothesis that plasminogen activator inhibitor-1 (PAI-1) may serve as a candidate marker for the malignancy of colorectal cancer (CRC), we performed a quantitative RT–PCR for PAI-1 gene and evaluated the possible relationship between PAI-1 gene expression levels and clinicopathological findings in CRC. A significant increase in PAI-1 expression scores was observed in lymph node metastasis-positive CRCs (2.19±0.43) compared to negative ones (0.35±0.42) (P=0.0037) as well as in distant metastasis-positive CRCs (3.50±1.18) compared to negative ones (0.99±0.30). The PAI-1 expression score markedly increased with the tumour stage (P=0.0063; ANOVA test). Moreover, multivariate analysis revealed the PAI-1 expression score to be a strong and independent prognostic factor for CRC (P=0.0432). These results suggested that PAI-1 might serve as a new parameter for the prediction of prognoses in CRC.

Urokinase plasminogen activator receptor is upregulated by Helicobacter pylori in human gastric cancer AGS cells via ERK, JNK, and AP-1

The gastric pathogen Helicobacter pylori (H. pylori) is suggested to be associated with gastric cancer progression. In this study, we investigated the effect of H. pylori on urokinase plasminogen activator receptor (uPAR) expression which has been known to correlate closely with gastric cancer invasion. H. pylori induced the uPAR expression in a time- and concentration-dependent manner. Specific inhibitors and inactive mutants of MEK-1 and JNK were found to suppress the H. pylori-induced uPAR expression and the uPAR promoter activity. Electrophoretic mobility shift assay and transient transfection study using an AP-1 decoy oligonucleotide confirmed that the activation of AP-1 is involved in the H. pylori-induced uPAR upregulation. The AGS cells treated with H. pylori showed a remarkably enhanced invasiveness, and this effect was partially abrogated by uPAR-neutralizing antibodies. These results suggest that H. pylori induces uPAR expression via Erk-1/2, JNK, and AP-1 signaling pathways and, in turn, stimulates the cell invasiveness in human gastric cancer AGS cells.

Expressions of urokinase-type plasminogen activator, its receptor and plasminogen activator inhibitor-1 in gastric cancer cells and effects of Helicobacter pylori

OBJECTIVE

Destruction of the extracellular matrix is essential for tumor invasion and metastasis. The relationship between Helicobacter pylori (H. pylori) infection and destruction of the extracellular matrix is not yet clear. Urokinase-type plasminogen activator (uPA) plays an important role in the destruction of the extracellular matrix and basement membrane. Urokinase-type plasminogen activator receptor (uPAR) and plasminogen activator inhibitor-1(PAI-1) appear to be associated with these processes. To clarify the role of H. pylori infection in the processes of destruction of the extracellular matrix and basement membrane in cancerous tissue, the effect of H. pylori on the expressions of uPA, uPAR and PAI-1 in cancer cells was investigated.

MATERIALS AND METHODS

Gastric cancer cell lines (MKN45, KATO-III) were co-cultured with H. pylori standard strain (NCTC11637), cagA-negative strain and clinical isolated strain. The specific inductions of uPA, uPAR and PAI-1 mRNA were examined by reverse transcription-polymerase chain reaction (RT-PCR) amplification. The secreted uPA antigen was measured by enzyme-linked immunosorbent assay (ELISA). To evaluate the role of transcription factor NF-kappaB in uPA and uPAR gene transcription with H. pylori stimulation, the effect of NF-kappaB inhibitor MG132 on H. pylori-induced uPA and uPAR mRNA expression was examined.

RESULTS

The expressions of both uPA and uPAR mRNAs in the gastric cancer cell lines (MKN45 and KATO- III) were increased markedly (uPA mRNA; MKN45: 12-fold, KATO-III: 5-fold) (uPAR mRNA; MKN45: 3-fold, KATO-III: 3-fold) with H. pylori NCTC11637 strain stimulation, whereas the expression levels of uPA and uPAR mRNA did not increase with cagA-negative strain stimulation. These cancer cell lines slightly secreted uPA antigen into the culture medium, and the amount of uPA antigen increased dramatically by stimulation with H. pylori NCTC11637 and cagA-positive clinical isolated strains. These gastric cancer cell lines also slightly secreted PAI-1 antigen into the culture medium, and the amount of PAI-1 antigen was not affected by H. pylori NCTC11637 stimulation. H. pylori-induced uPA and uPAR mRNA expressions were strongly down-regulated by pretreatment with MG132 in both cell lines.

CONCLUSIONS

The results of this study indicated the possibility that cagA-positive H. pylori may play an important role not only in tissue remodeling, angiogenesis and wound healing but also in the process of degradation of the extracellular matrix breakdown, tumor invasion and metastasis by inducing uPA and uPAR complex in the gastric cancer cells.

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.

Plasminogen Activator Inhibitor-1 as a Potential Marker for the Malignancy of Esophageal Squamous Cell Carcinoma

PURPOSE AND EXPERIMENTAL DESIGN

To test whether plasminogen activator inhibitor-1 (PAI-1) can serve as a candidate marker for the malignancy of esophageal squamous cell carcinoma (SCC), we performed a quantitative reverse transcription-PCR for PAI-1 gene and evaluated the possible relationship between PAI-1 gene expression levels and clinicopathological findings in esophageal SCC.

RESULTS

Significant increases in PAI-1 scores were observed in metastasis-positive esophageal SCCs (3.08 +/- 0.80) compared with metastasis-negative ones (-0.31 +/- 0.62; P = 0.0042). PAI-1 expression scores significantly increased with tumor stage (P = 0.05, ANOVA).

CONCLUSIONS

These results suggested that PAI-1 might serve as a new parameter for prediction of prognosis in esophageal SCC.

High tumor tissue concentration of urokinase plasminogen activator receptor is associated with good prognosis in patients with ovarian cancer

The urokinase plasminogen activator (uPA) system is involved in tumor growth and metastasis. We assayed the components of the uPA system in homogenates of 64 primary epithelial ovarian tumors and 5 metastases and evaluated the association of these parameters to prognosis in the 51 malignant cases. The levels of uPA, PAI-2 and the uPA:PAI-1 complex increased with progressive loss of histological differentiation (p(trend) <0.001, <0.05 and <0.001). The level of PAI-1 was higher in poorly than in well/moderately differentiated tumors (p = 0.03). The content of uPAR was lower in benign tumors as compared to borderline malignancies (p = 0.002), invasive primary tumors (p < 0.001), and metastases (p = 0.002). Surprisingly, the level of uPAR was lower in poorly differentiated as compared to both borderline (p = 0.01) and well differentiated malignant tumors (p = 0.005). Also, the level of uPAR was lower in advanced as compared to early stages of the disease (p(trend) = 0.002). The median follow-up time for patients was 5.8 years. High tumor tissue levels of uPAR were associated with longer postoperative survival (HR = 0.4, 95% CI = 0.2-0.8, p = 0.01). In contrast, shorter survival was evident in patients with high tumor levels of uPA from 2 years on after operation (HR = 4.6, 95% CI = 1.2-17, p = 0.02). High tPA levels tended to be associated with shorter overall survival after 2 years (HR = 2.9, 95% 95% CI = 0.9-9.8, p = 0.08). Although high tumor tissue content of uPAR was associated with a less aggressive phenotype characterized by well differentiated histology and longer survival, low content of uPAR in the poorly differentiated tumors and metastases presumably results from increased elimination of uPAR.

Variations of components of the plasminogen activation system with the cell cycle in benign prostate tissue and prostate cancer

BACKGROUND

Components of the fibrinolytic system are involved in tumor cell invasion and metastasis. Previous investigations suggested a cell cycle-dependent expression of urokinase-type plasminogen activator (u-PA) in epithelial cells. In order to determine a correlation of cell cycle phases with the fibrinolytic system, we investigated the expression of u-PA, tissue-type plasminogen activator (t-PA), and plasminogen activator inhibitor type 1 (PAI-1) in normal and tumor-containing prostate extracts and analyzed a possible relationship with flow cytometry-determined proliferative activity of the samples. Cell cycle phases were correlated with fibrinolytic parameters in prostate tissue.

METHODS

Samples were obtained from patients undergoing radical prostatectomy for prostate cancer and separated into two portions for DNA analysis and the detection of u-PA, t-PA, and PAI-1. Flow cytometric analysis was performed according to the Vindelov technique. The concentrations of u-PA, t-PA, and PAI-1 were determined from tissue extracts after homogenization by an enzyme-linked immunosorbent assay (ELISA) technique.

RESULTS

Correlations of u-PA and t-PA expression with the frequency of G0/G1, S, G2M, S-phase fraction (SPF), and proliferation index (PI) for normal prostate and prostate cancer revealed no significant correlation. The only significant finding was observed in normal tissue revealing a positive correlation between PAI-1 expression and G0/G1 and a negative correlation with S-phase, SPF, and PI. No dependence of PAI-1 expression on different cell phases was found in prostate cancer. Furthermore, no significant correlation of u-PA, t-PA, and PAI-1 with cell cycles in organ-confined (<pT3a) and disseminated (> or = pT3a) tumors was found. No significant correlation in prostate cancer of components of the fibrinolytic system differentiated according to tumor grade or perineural tumor infiltration and cell cycle analysis was found. Only in highly differentiated G1 (Gleason 2-4) cancer, u-PA had a significant positive correlation with G2M-phase.

CONCLUSION

Absence of a correlation between levels of components of the fibrinolytic system and cell cycle phases suggests that the reported association between increases of some of these components and aggressive biological behavior of prostate cancer is secondary to non-cell cycle-related mechanisms.

p27(Kip1) loss does not predict survival in patients with advanced gastric carcinoma

BACKGROUND

p27(Kip1) is a cyclin-dependent kinase inhibitor whose loss is associated with disease progression and an unfavorable outcome in several malignancies. The authors studied its expression in a consecutive series of resected gastric carcinomas.

METHODS

Expression of p27(Kip1) in 71 advanced gastric carcinomas and 10 lymph nodes containing metastases was determined using an avidin-biotin-peroxidase immunohistochemical method. The relations between p27(Kip1) expression and pathologic features, patient characteristics, and survival were analyzed.

RESULTS

p27(Kip1) levels in gastric carcinomas ranged from 0.63-82.97% (median, 23. 10%; mean, 27.99%). There was no association found between p27(Kip1) expression and patient gender (P = 0.21), patient age (P = 0.13), tumor stage (P = 0.17), tumor grade (P = 0.22), or histologic type (P = 0.72). Univariate analysis showed that long term survival was related to stage (P < 0.0001) and grade (P = 0.03). However, tumors with p27(Kip1) levels above and below the median value were associated with a similar outcome, regardless of whether all cases (P = 0.19) or those without metastatic disease (P = 0.50) or those with residual or metastatic disease (P = 0.92) were included. When entered into a multivariate analysis, stage (P < 0.0001) and grade (P = 0.05), but not p27(Kip1) levels (P = 0.16), were found to be related to patient outcome. In lymph node metastases, p27(Kip1) expression (median, 16.5%) was similar to that found in the corresponding primary lesion (median, 30.9%).

CONCLUSIONS

p27(Kip1) may play a role in the pathogenesis and progression of gastric carcinoma, but its expression is unlikely to be useful as a prognostic indicator, at least in European patients with advanced disease.

Correlation of tissue and blood plasminogen activation system in breast cancer

The plasminogen activation system plays a crucial role during cancer invasion and metastasis. In the solid tumor, urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor type-1 (PAI-1) and uPA receptor (uPAR) are considered as prognostic factors. In this study, we have investigated whether secretion of the uPA, PAI-1 and uPAR from the primary breast cancer tissue can be detected in the blood of the patients using the ELISA assay. We have found that the plasminogen activation system (uPA, PAI-1, uPAR) of tumor tissue is activated from the early stage of breast cancer. However, only a number of metastatic lymph nodes was a prognostic factor in multivariate analysis for relapse. The blood level of the plasminogen activation system correlated with that of tissue in an order of uPAR (r(2)=0.61; P=0.001), uPA (r(2)=0.35; P=0.001) and PAI-1 (r(2)=0.11; P=0.001). We conclude that the total uPAR level of cancer tissue can be substituted by that which is detected in the blood for further clinical applications.

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.

Analysis of fibrinolytic proteins in relation to DNA ploidy in prostate cancer

The tissue concentrations of urokinase-type plasminogen activator (u-PA), urokinase-type plasminogen activator receptor (u-PAR), plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) were investigated by an ELISA technique in normal and malignant samples of the prostate from 24 patients undergoing radical prostatectomy for organ-confined prostate cancer. The median concentration of u-PA was significantly higher in cancerous than in normal prostate tissue (p = 0.006). No significant increase of u-PAR, PAI-1 and t-PA was found in cancer tissue in comparison with the benign samples (p > 0.05). Assessment of the relationship between fibrinolytic proteins and DNA ploidy revealed an increased u-PA, u-PAR and PAI-1 in diploid prostate cancer as compared with the normal controls. However, in aneuploid cancer u-PA remained high but u-PAR and PAI-1 were decreased. This led to a higher local concentration of u-PA in aneuploid samples than in normal prostate and in diploid prostate cancer. No alteration of median t-PA was found in benign prostate or in diploid or aneuploid prostate cancer. The altered expression of u-PA, u-PAR and PAI-1 in diploid and aneuploid prostate cancer suggests a possible role of fibrinolytic proteins in the different biologic behavior of tumors, and may be one explanation for the higher metastatic potential of aneuploid tumors.