Urokinase plasminogen activator and plasminogen activator inhibitor type-1 in nonsmall-cell lung cancer: relation to prognosis and angiogenesis

SERPINE1 and SERPINB7 as potential biomarkers for intravenous vitamin C treatment in non-small-cell lung cancer

High dose intravenous vitamin C (IVC) has been proposed as a pro-oxidant anticancer agent. However, there is a lack of biomarkers that are specific for this treatment. Here, we explored profiles of gene expression responding to IVC treatment in non-small cell lung cancer (NSCLC) cells as an effort for potential biomarker discovery. Genome-wide RNA-seq was performed in human NSCLC cell lines treated with pharmacological concentrations of vitamin C(VitC) for differential expression of genes. The identified genes were analyzed for correlations with patient prognosis using data from the Kaplan-Meier Plotter and the Human Protein Atlas databases. Further, tumor samples from a retrospective study of 153 NSCLC patients were analyzed with immunohistochemistry for expression of targeted genes, and patient prognosis was correlated to these genes. Two genes, namely SERPINE1 and SERPINB7 were found to be downregulated in NSCLC cells following VitC treatment. Combined patient data from the cohort analysis and online databases revealed that these 2 genes presented an unfavorable prognostic prediction of overall survival (OS) in NSCLC patients receiving standard of care. However, high expression level of these 2 genes were associated with prolonged OS in NSCLC patients receiving IVC in addition to standard of care. These data revealed that SERPINE1 and SERPINB7 have the potential to serve as predictive factors indicating favorable responses to IVC treatment in patients with NSCLC. Further validations are warranted.

CD43 (sialophorin) is involved in the induction of extracellular matrix remodeling and angiogenesis by lung cancer cells

Aberrant expression of CD43 in malignant tumors of nonhematopoietic origin such as those from lung, cervix, colon, and breast has been shown to correlate with poor prognosis, providing tumor cells with enhanced motility, anchorage-independent growth, and in vivo tumor size, while protecting the cells of NK lysis and apoptosis. To further characterize the role of CD43 in cell transformation, we tested whether interfering its expression modified the capacity of the A549 non-small cell lung cancer cells to secrete molecules contributing to malignancy. The proteomic analysis of the secretome of serum-starved A549 cells revealed that cells expressing normal levels of CD43 released significantly high levels of molecules involved in extracellular matrix organization, angiogenesis, platelet degranulation, collagen degradation, and inflammation, as compared to CD43 RNAi cells. This data reveals a novel and unexpected role for CD43 in lung cancer development, mainly in remodeling the tumor microenvironment.

The urokinase-type plasminogen activator and inhibitors in resectable lung adenocarcinoma

BACKGROUND

The urokinase-type plasminogen activator (uPA) system is closely related to the occurrence and progression of cancer in many aspects. Previous studies demonstrated that the conclusions about the prognosis value of uPA, plasminogen activator inhibitor 1 (PAI-1) and plasminogen activator inhibitor 2 (PAI-2) in lung cancer are controversial, so this study was performed for the exploration of the predictive effect of uPA, PAI-1 and PAI-2 on the overall survival (OS) of resectable pulmonary adenocarcinoma patients.

METHODS

UPA, PAI-1 and PAI-2 expression levels were assayed by immunohistochemical staining based on tissue microarray (TMA) that is composed of formalin-fixed paraffin-embedded specimens from 84 resectable lung adenocarcinoma patients from July 2004 to June 2009. The relationship of IHC, mRNA expression levels of three molecules were investigated respectively. The three molecules' relationship with clinicopathologic parameters and OS was explored by Chi-square, Kaplan-Meier, and Cox regression analyses. The Cancer Genome Atlas (TCGA) database was used to analyze differential gene expressions of RNA-sequencing data of pulmonary adenocarcinoma and normal tissues, and Kaplan-Meier methods were adopted to confirm the prognostic value of uPA, PAI-1 and PAI-2 in resectable lung adenocarcinoma in TCGA database and the R package MethylMix was used to conduct an analysis integrating methylation data and gene expression of RNA-sequencing data based on TCGA.

RESULTS

UPA, PAI-1 and PAI-2 had much higher IHC expression levels in tumor than those in the normal tissues (uPA, Z = -10.511; PAI-1, Z = -4.836; PAI-2, Z = -6.794; all P < 0.0001). High DNA methylation level of gene uPA resulted in the decrease of its expression. In addition, expression level of PAI-2 was positively associated with tumor size (χ² = 8.372, P =  0.004). Multivariate analyses showed TNM stage III was an independent adverse prognostic factor (hazard ratio = 3.736, 95 % confidence interval = 1.097-12.72, P =  0.035). Kaplan-Meier method revealed that uPA, PAI-1 and PAI-2 expression levels were not related to the OS for 84 resectable lung adenocarcinoma patients. According to TCGA data, PAI-1 expression level was identified as a potential adverse predictor for prognosis of resectable lung adenocarcinoma (Gehan-Breslow-Wilcoxon test, P = 0.025).

CONCLUSIONS

Our data show that, the expression levels of uPA, PAI-1 and PAI-2 are significantly up-regulated in resectable lung adenocarcinoma. Besides, this study highlights PAI-1 as a latent adverse prognostic factor in resectable adenocarcinoma of lung.

Global transcriptomic analysis identifies SERPINE1 as a prognostic biomarker associated with epithelial-to-mesenchymal transition in gastric cancer

Background

The plasminogen activation system plays a pivotal role in regulating tumorigenesis. In this work, we aim to identify key regulators of plasminogen activation associated with tumorigenesis and explore potential mechanisms in gastric cancer (GC).

Methods

Gene profiling datasets were extracted from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) were screened for and obtained by the GEO2R tool. The Database for Annotation, Visualization and Integrated Discovery was used for GO and KEGG enrichment analysis. Gene set enrichment analysis (GSEA) was performed to verify molecular signatures and pathways among The Cancer Genome Atlas or GEO datasets. Correlations between SERPINE1 and markers of epithelial-to-mesenchymal transition (EMT) were analyzed using the GEPIA database and quantitative real-time PCR (qRT-PCR). Interactive networks of selected genes were built by STRING and Cytoscape software. Finally, selected genes were verified with the Kaplan–Meier (KM) plotter database.

Results

A total of 104 overlapped upregulated and 61 downregulated DEGs were obtained. Multiple GO and KEGG terms associated with the extracellular matrix were enriched among the DEGs. SERPINE1 was identified as the only regulator of angiogenesis and the plasminogen activator system among the DEGs. A high level of SERPINE1 was associated with a poor prognosis in GC. GSEA analysis showed a strong correlation between SERPINE1 and EMT, which was also confirmed with the GEPIA database and qRT-PCR validation. FN1, TIMP1, MMP2, and SPARC were correlated with SERPINE1.The KM plotter database showed that an overexpression of these genes correlated with a shorter survival time in GC patients.

Conclusions

In conclusion, SERPINE1 is a potent biomarker associated with EMT and a poor prognosis in GC. Furthermore, FN1, TIMP1, MMP2, and SPARC are correlated with SERPINE1 and may serve as therapeutic targets in reversing EMT in GC.

Inhibition of PAI-1 limits chemotherapy resistance in lung cancer through suppressing myofibroblast characteristics of cancer-associated fibroblasts

Plasminogen activator inhibitor‐1 (PAI‐1) promotes pulmonary fibrosis through increasing myofibroblast (MF) characteristics, expressing alpha‐smooth muscle actin (α‐SMA) in fibroblasts. Fibroblasts in the tumour stroma are called cancer‐associated fibroblasts (CAFs). Some CAFs have MF characteristics and substantially promote tumour progression and chemotherapy resistance. This study determined whether inhibition of PAI‐1 suppressed MF characteristics of CAFs and limited chemotherapy resistance in lung cancer. To investigate cellular PAI‐1 expression and its correlation with α‐SMA expression of CAFs, 34 patients’ paraffin‐embedded lung adenocarcinoma tissue sections were immunohistochemically stained for PAI‐1 and α‐SMA. Immunohistochemical analysis of lung adenocarcinoma tissues showed that PAI‐1 expression was correlated with that of α‐SMA (r = 0.71, p < 0.001). Furthermore, in vitro, α‐SMA expression of CAFs was limited by PAI‐1 inhibition, and apoptosis of CAFs was increased. In addition, the effectiveness of cisplatin on lung cancer cells co‐cultured with CAFs was increased by suppressing α‐SMA expression using PAI‐1 inhibitor. In lung adenocarcinoma tissues, PAI‐1 expression was associated with T factor and TNM stage. Our data suggest that inhibition of PAI‐1 increased the chemotherapeutic effect on lung cancer through suppressing the MF characteristics of CAFs. Hence, PAI‐1 might be a promising therapeutic target for patients with chemotherapeutic‐resistant lung cancer with CAFs.

Serum proteome mapping of EGF transgenic mice reveal mechanistic biomarkers of lung cancer precursor lesions with clinical significance for human adenocarcinomas

Atypical adenomatous hyperplasia (AAH) of the lung is a pre-invasive lesion (PL) with high risk of progression to lung cancer (LC). However, the pathways involved are uncertain. We searched for novel mechanistic biomarkers of AAH in an EGF transgenic disease model of lung cancer. Disease regulated proteins were validated by Western immunoblotting and immunohistochemistry (IHC) of control and morphologically altered respiratory epithelium. Translational work involved clinical resection material. Collectively, 68 unique serum proteins were identified by 2DE-MALDI-TOF mass spectrometry and 13 reached statistical significance (p < 0.05). EGF, amphiregulin and the EGFR endosomal sorting protein VPS28 were induced up to 5-fold while IHC confirmed strong induction of these proteins. Furthermore, ApoA1, α-2-macroglobulin, and vitamin-D binding protein were nearly 6- and 2-fold upregulated in AAH; however, ApoA1 was oppositely regulated in LC to evidence disease stage dependent regulation of this tumour suppressor. Conversely, plasminogen and transthyretin were highly significantly repressed by 3- and 20-fold. IHC confirmed induced ApoA1, Fetuin-B and transthyretin expression to influence calcification, inflammation and tumour-infiltrating macrophages. Moreover, serum ApoA4, ApoH and ApoM were 2-, 2- and 6-fold repressed; however tissue ApoM and sphingosine-1-phosphate receptor expression was markedly induced to suggest a critical role of sphingosine-1-phosphate signalling in PL and malignant transformation. Finally, a comparison of three different LC models revealed common and unique serum biomarkers mechanistically linked to EGFR, cMyc and cRaf signalling. Their validation by IHC on clinical resection material established relevance for distinct human lung pathologies. In conclusion, we identified mechanistic biomarker candidates recommended for in-depth clinical evaluation.

Plasminogen activator inhibitor-1 in cancer research

[Despite as a major inhibitor of urokinase (uPA), paradoxically,] Plasminogen activator inhibitor-1 (PAI-1) has been validated to be highly expressed in various types of tumor biopsy tissues or plasma compared with controls based on huge clinical data bases analysis, more importantly, PAI-1 alone or in conjunction with uPA have been identified as prognostic for disease progression and relapse in certain cancer types. particularly in breast cancer. In addition to play important roles in cell adhesion, migration and invasion, PAI-1 has been reported to induce tumor vascularization and thus promote cell dissemination and tumor metastasis. Furthermore, there are many tumor promoting factors involved in the modulation of PAI-1 expression and activity, which will strengthen the pro-tumorigenic roles of PAI-1. Undoubtedly, PAI-1 may be a promising target for therapeutic intervention of specific cancer treatment. In fact, some PAI-1 inhibitors are currently being evaluated in cancer therapy, which may be developed to new antitumor agents in the future.

Plasminogen activator inhibitor-1 enhances radioresistance and aggressiveness of non-small cell lung cancer cells

Acquired resistance of tumor cells during treatment limits the clinical efficacy of radiotherapy. Recent studies to investigate acquired resistance under treatment have focused on intercellular communication because it promotes survival and aggressiveness of tumor cells, causing therapy failure and tumor relapse. Accordingly, a better understanding of the functional communication between subpopulations of cells within a tumor is essential to development of effective cancer treatment strategies. Here, we found that conditioned media (CM) from radioresistant non-small cell lung cancer (NSCLC) cells increased survival of radiosensitive cells. Comparative proteomics analysis revealed plasminogen activator inhibitor-1 (PAI-1) as a key molecule in the secretome that acts as an extracellular signaling trigger to strengthen resistance to radiation. Our results revealed that expression and secretion of PAI-1 in radioresistant cells was increased by radiation-induced transcription factors, including p53, HIF-1α, and Smad3. When CM from radioresistant cells was applied to radiosensitive cells, extracellular PAI-1 activated the AKT and ERK1/2 signaling pathway and inhibited caspase-3 activity. Our study also proposed that PAI-1 activates the signaling pathway in radiosensitive cells via extracellular interaction with its binding partners, not clathrin-mediated endocytosis. Furthermore, secreted PAI-1 increased cell migration capacity and expression of EMT markers in vitro and in vivo. Taken together, our findings demonstrate that PAI-1 secreted from radioresistant NSCLC cells reduced radiosensitivity of nearby cells in a paracrine manner, indicating that functional inhibition of PAI-1 signaling has therapeutic potential because it prevents sensitive cells from acquiring radioresistance.

Expression Analysis of Angiogenesis-Related Genes in Bulgarian Patients with Early-Stage Non-Small Cell Lung Cancer

Aims and background

Angiogenesis is a key process in the early stages of tumor development. In this study we aimed to evaluate the expression of a panel of angiogenesis-related genes in a group of Bulgarian patients with early-stage non-small cell lung cancer (NSCLC).

Methods and study design

We analyzed the expression of 84 genes associated with the angiogenic process in 12 NSCLCs of two histological subtypes: 7 adenocarcinomas and 5 squamous cell carcinomas. Eight peripheral nontumorous tissues were used as controls. We performed real-time PCR on pathway-specific gene arrays (SABiosciences).

Results

Our pilot study identified upregulated genes in early-stage NSCLC including growth factors (TGFA and EFNA3), the adhesion molecule THBS2, cytokines and chemokines (MDK, CXCL9, CXCL10), and the serine protease PLAU. Several genes showed downregulation including one growth factor (FIGF), the receptors for growth factors TEK and S1PR1 as well as adhesion molecules (COL4A3 and CDH5), the cytokine IL6, the matrix protein LEP and the transcription factor NOTCH4. The study demonstrated deregulated genes specific for the two histological subtypes including the transcription factor HAND2, which was overexpressed in squamous cell carcinomas but not adenocarcinomas.

Conclusions

Despite the limited number of patients, our results demonstrated the potential of angiogenesis-related genes as biomarkers in the early stages of NSCLC development. Free full text available at www.tumorionline.it

Prognostic value of urokinase plasminogen activator system in non-small cell lung cancer: A systematic review and meta-analysis

Current relevant research suggests there are significant differences between the expression of the urokinase plasminogen activator (uPA) system in cancer tissues and in normal tissues. However, the potential effectiveness of the uPA system as a prognostic biomarker of non-small cell lung cancer (NSCLC) remains unclear. In the present study, a systematic review and meta-analysis were performed to evaluate the relevance of the uPA system in the prognosis of patients with NSCLC. Using the PubMed, EMBASE, Web of Science and Cochrane Library databases, data from relevant academic journal articles were extracted and subjected to analysis. Associations between expression profiles pertaining to the uPA system and the overall survival (OS) of patients with NSCLC were analyzed. The study incorporated data from 11 independent journal articles and these reports included a total of 937 patients with NSCLC. The meta-analysis results revealed that increased expression of urokinase plasminogen activator (uPA) and PA inhibitor type 1 (PAI-1) exhibited no significant association with poor OS [hazard ratio (HR)-uPA=1.07 (0.87-1.31), P=0.53; HR-PAI-1=1.02 (0.63-1.65), P=0.94]. Similarly, reduced expression of PAI type 2 (PAI-2) did not significantly correlate with poor OS [HR-PAI-2=1.58 (0.64-3.90); P=0.32]. Notably, however, a significant association was observed between increased expression levels of uPA receptor (uPAR) and poor OS for NSCLC [HR-uPAR=1.50 (1.04-2.15); P=0.03]. Therefore, the expression of uPAR in the uPA system of patients with NSCLC could be used as a novel clinical biomarker to evaluate the prognosis of NSCLC. The utilization of this biomarker may provide a platform for the further development of targeted drugs for the treatment of NSCLC.

Low expression of SerpinB2 is associated with reduced survival in lung adenocarcinomas

Lung cancer is a leading cause of cancer deaths worldwide and new biomarkers are of utmost importance. Studies have indicated that the anti-plasminogen activators SerpinB2 and Neuroserpin, and the adhesion molecule L1CAM, have a coordinated impact on development of metastasis. Here, we examined whether expression of these markers was associated with clinico-pathologic characteristics and prognosis in resected non-small cell lung cancer (NSCLC).

Surgical specimens from 438 NSCLC patients treated at Haukeland University Hospital, Bergen, Norway (1993-2010) were included (median age 68 years; 213 adenocarcinomas, 135 squamous cell carcinomas, 90 others). Representative tumor sections were stained for SerpinB2, Neuroserpin, and L1CAM.

Low expression of SerpinB2 was associated with reduced lung cancer specific survival (LCSS) in adenocarcinomas (p = 0.017), also in stage I (p = 0.031). In contrast, high SerpinB2 was associated with reduced LCSS in stage I squamous cell carcinomas (p = 0.022). Although Neuroserpin and L1CAM showed some associations with clinico-pathologic phenotype, there were no associations with survival. In multivariate survival analysis of adenocarcinomas, low SerpinB2 demonstrated independent prognostic value (HR 1.8, p = 0.008).

In summary, low expression of SerpinB2 in lung adenocarcinomas was an independent prognostic factor. In contrast to findings by others, we found no impact of L1CAM on survival. Introduction

The role of serpins in tumor cell migration

Tumor cells are characterized by uncontrolled cell growth at a primary site that is caused by genetic alterations. Tumor cells that metastasize from their primary site to distant locations are commonly referred to as malignant. Cell migration is a critical step in this process. The ability of tumor cells to migrate and invade is partly controlled by proteolytic enzymes. These enzymes are secreted by either the tumor cells themselves or adjacent cells. They represent all classes of proteases, including serine and cysteine proteases. Serine proteases, in particular urokinase plasminogen activator (uPA), initiate a proteolytic cascade that culminates in degrading components of the extracellular matrix (ECM). Some serine proteases are controlled by a superfamily of proteins known as serpins. This minireview provides an overview of serpins that are vital in regulating tumor cell migration and progressing cancer.

Plasminogen Activator Inhibitor-2 Plays a Leading Prognostic Role among Protease Families in Non-Small Cell Lung Cancer

Background

In lung cancer, uPA, its receptor (uPAR), and the inhibitors PAI-1 and PAI-2 of the plasminogen activator family interact with MMP-2 and MMP-9 of the MMP family to promote cancer progression. However, it remains undetermined which of these markers plays the most important role and may be the most useful indicator to stratify the patients by risk.

Methods

We determined the individual prognostic value of these 6 markers by analyzing a derivation cohort with 98 non-small cell lung cancer patients by immunohistochemical staining. The correlation between the IHC expression levels of these markers and disease prognosis was investigated, and an immunohistochemical panel for prognostic prediction was subsequently generated through prognostic model analysis. The value of the immunohistochemical panel was then verified by a validation cohort with 91 lung cancer patients.

Results

In derivation cohort, PAI-2 is the most powerful prognostic factor (HR = 2.30; P = 0.001), followed by MMP-9 (HR = 2.09; P = 0.019) according to multivariate analysis. When combining PAI-2 and MMP-9, the most unfavorable prognostic group (low PAI-2 and high MMP-9 IHC expression levels) showed a 6.40-fold increased risk of a poor prognosis compared to the most favorable prognostic group (high PAI-2 and low MMP-9 IHC expression levels). PAI-2 and MMP-9 IHC panel could more precisely identify high risk patients in both derivation and validation cohort.

Conclusions

We revealed PAI-2 as the most powerful prognostic marker among PA and MMP protease family even after considering their close relationships with each other. By utilizing a combination of PAI-2 and MMP-9, more precise prognostic information than merely using pathological stage alone can be obtained for lung cancer patients.

Impact of proteolytic enzymes in colorectal cancer development and progression

Tumor invasion and metastasis is a highly complicated, multi-step phenomenon. In the complex event of tumor progression, tumor cells interact with basement membrane and extracellular matrix components. Proteolytic enzymes (proteinases) are involved in the degradation of extracellular matrix, but also in cancer invasion and metastasis. The four categories of proteinases (cysteine-, serine-, aspartic-, and metalloproteinases) are named and classified according to the essential catalytic component in their active site. We and others have shown that proteolytic enzymes play a major role not only in colorectal cancer (CRC) invasion and metastasis, but also in malignant transformation of precancerous lesions into cancer. Tissue and serum-plasma antigen concentrations of proteinases might be of great value in identifying patients with poor prognosis in CRC. Our results, in concordance with others indicate the potential tumor marker impact of proteinases for the early diagnosis of CRC. In addition, proteinases may also serve as potential target molecules for therapeutic agents.

Plasminogen activator inhibitor-1 and susceptibility to lung cancer: a population genetics perspective

AIM

The aim of this study was to investigate the polymorphism frequency of plasminogen activator inhibitor-1 (PAI-1) (rs1799889) 4G/5G in patients with lung cancer.

METHODS

In this study, 286 genomic DNAs (154 lung cancer patients+132 subjects without lung cancer) were analyzed. Polymorphisms were determined by using the polymerase chain reaction (PCR) method, with 4G and 5G allele-specific primers. PCR products were assessed by a charge-coupled device camera and exposed to 2% agarose gel electrophoresis.

RESULTS

The frequencies of the PAI-1 gene 4G/5G genotypes were found to be 21% 4G/4G, 16% 4G/5G, and 62% 5G/5G in the control group and 31.4% 4G/4G, 30.8% 4G/5G, and 37.8% 5G/5G in the patient group. It was determined that the 5G/5G genotype frequency was high in patients in comparison with other genotypes.

CONCLUSIONS

This study found a statistically significant difference between the groups with respect to genotype distribution. Consequently, we can say that the PAI-1 gene 4G/5G polymorphism is associated with lung cancer in Turkey.

Plasma Levels of Plasminogen Activator Inhibitor Type 1 and Vitronectin in Children With Cancer

BACKGROUND

The plasminogen activator system controls intravascular fibrin deposition; besides, it also participates in a wide variety of physiologic and pathologic processes, including cancer.

PROCEDURE

In this study, we examined the levels of plasminogen activator inhibitor 1 (PAI-1) and vitronectin in 32 newly diagnosed pediatric patients with malignancies, determined by enzyme-linked immunosorbent assay between January 2009 and January 2010 and compared them to 35 age-matched healthy children, using SPSS 16.0 software.

RESULTS

The mean level of PAI-1 was 23.02 ± 15 (8.2-71.19) ng/mL and vitronectin was 83.10% ± 23.77% (12%-126%) in the tumor group. Thirty-five healthy children in the same age range were enrolled in the control group. The levels of PAI-1 and vitronectin were 23.63 ± 10.44 (11.67-58.85) ng/mL and 85% ± 20.85% (39%-126%), respectively. No significant difference was found between the 2 groups by independent sample t-test (P = .86 and P = .69).

CONCLUSIONS

This is a preliminary study done in children with malignancies, investigating PAI-1 and vitronectin. Further study is needed, including larger trials and tumor tissue with histopathological examination as in adults.

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.

Plasminogen Activator Inhibitor Type 1 (PAI-1) A15T Gene Polymorphism Is Associated with Prognosis in Patients with EGFR Mutation Positive Pulmonary Adenocarcinoma

Background

Plasminogen activator inhibitor type 1 (PAI-1), an important regulator of plasminogen activator system which controls degradation of extracellular membrane and progression of tumor cells, and PAI-1 gene polymorphic variants have been known as the prognostic biomarkers of non-small cell lung cancer patients. Recently, experimental in vitro study revealed that transforming growth factor-β1 initiated PAI-1 transcription through epithelial growth factor receptor (EGFR) signaling pathway. However, there is little clinical evidence on the association between PAI-1 A15T gene polymorphism and prognosis of Korean population with pulmonary adenocarcinoma and the influence of activating mutation of EGFR kinase domain.

Methods

We retrospectively reviewed the medical records of 171 patients who were diagnosed with pulmonary adenocarcinoma and undergone EGFR mutation analysis from 1995 through 2009.

Results

In all patients with pulmonary adenocarcinoma, there was no significant association between PAI-1 A15T polymorphic variants and prognosis for overall survival. However, further subgroup analysis showed that the group with AG/AA genotype had a shorter 3-year survival time than the group with GG genotype in patients with EGFR mutant-type pulmonary adenocarcinoma (mean survival time, 24.9 months vs. 32.5 months, respectively; p=0.015). In multivariate analysis of 3-year survival for patients with pulmonary adenocarcinoma harboring mutant-type EGFR, the AG/AA genotype carriers had poorer prognosis than the GG genotype carriers (hazard ratio, 7.729; 95% confidence interval, 1.414-42.250; p=0.018).

Conclusion

According to our study of Korean population with pulmonary adenocarcinoma, AG/AA genotype of PAI-1 A15T would be a significant predictor of poor short-term survival in patients with pulmonary adenocarcinoma harboring mutant-type EGFR.

Vessel co-option in primary human tumors and metastases: an obstacle to effective anti-angiogenic treatment?

Angiogenesis has been regarded as essential for tumor growth and progression. Studies of many human tumors, however, suggest that their microcirculation may be provided by nonsprouting vessels and that a variety of tumors can grow and metastasize without angiogenesis. Vessel co-option, where tumor cells migrate along the preexisting vessels of the host organ, is regarded as an alternative tumor blood supply. Vessel co-option may occur in many malignancies, but so far mostly reported in highly vascularized tissues such as brain, lung, and liver. In primary and metastatic lung cancer and liver metastasis from different primary origins, as much as 10–30% of the tumors are reported to use this alternative blood supply. In addition, vessel co-option is introduced as a potential explanation of antiangiogenic drug resistance, although the impact of vessel co-option in this clinical setting is still to be further explored. In this review we discuss tumor vessel co-option with specific examples of vessel co-option in primary and secondary tumors and a consideration of the clinical implications of this alternative tumor blood supply.

Both primary and metastatic tumors use preexisting host tissue vessels as their blood supply. Tumors may grow to a clinically detectable size without angiogenesis and makes them less likely to respond to drugs designed to target the abnormal vasculature produced by angiogenesis, but further studies to explore the biological and clinical implication of these co-opted vessels is needed.

Platelet-derived growth factor-C (PDGF-C) activation by serine proteases: implications for breast cancer progression

The PDGF (platelet-derived growth factor) family members are potent mitogens for cells of mesenchymal origin and serve as important regulators of cell migration, survival, apoptosis and transformation. Tumour-derived PDGF ligands are thought to function in both autocrine and paracrine manners, activating receptors on tumour and surrounding stromal cells. PDGF-C and -D are secreted as latent dimers, unlike PDGF-A and -B. Cleavage of the CUB domain from the PDGF-C and -D dimers is required for their biological activity. At present, little is known about the proteolytic processing of PDGF-C, the rate-limiting step in the regulation of PDGF-C activity. In the present study we show that the breast carcinoma cell line MCF7, engineered to overexpress PDGF-C, produces proteases capable of cleaving PDGF-C to its active form. Increased PDGF-C expression enhances cell proliferation, anchorage-independent cell growth and tumour cell motility by autocrine signalling. In addition, MCF7-produced PDGF-C induces fibroblast cell migration in a paracrine manner. Interestingly, PDGF-C enhances tumour cell invasion in the presence of fibroblasts, suggesting a role for tumour-derived PDGF-C in tumour-stromal interactions. In the present study, we identify tPA (tissue plasminogen activator) and matriptase as major proteases for processing of PDGF-C in MCF7 cells. In in vitro studies, we also show that uPA (urokinase-type plasminogen activator) is able to process PDGF-C. Furthermore, by site-directed mutagenesis, we identify the cleavage site for these proteases in PDGF-C. Lastly, we provide evidence suggesting a two-step proteolytic processing of PDGF-C involving creation of a hemidimer, followed by GFD-D (growth factor domain dimer) generation.

ARNTL2 and SERPINE1: potential biomarkers for tumor aggressiveness in colorectal cancer

PURPOSE

Cathepsin and plasmin may favor cancer cell invasion degrading extracellular matrix. Plasmin formation from plasminogen is regulated by plasminogen activator inhibitor type-1 (PAI-1). ARNTL2 activates the promoters of the PAI-1 gene, officially called SERPINE1, driving the circadian variation in circulating PAI-1 levels.

METHODS

We evaluated ARNTL2 and SERPINE1 expression in 50 colorectal cancer specimens and adjacent normal tissue and in colon cancer cell lines.

RESULTS

We found up-regulation of ARNTL2 (P = 0.004) and SERPINE1 (P = 0.002) in tumor tissue. A statistically significant association was found between high ARNTL2 mRNA levels and vascular invasion (P < 0.0001), and between high SERPINE1 mRNA levels and microsatellite instability (MSI-H and MSI-L, P = 0.025). Sorting the subjects into quartile groups, a statistically significant association was found between high ARNTL2 expression and lymph node involvement (P < 0.001), between high SERPINE1 expression and grading (P < 0.001) and between high SERPINE1 expression and MSI H-L (P < 0.0001). In SW480 cells, a more proliferative model compared to CaCo2 cells, there were higher mRNA levels of ARNTL2 (P < 0.001) and SERPINE1 (P = 0.001).

CONCLUSION

ARNTL2 and SERPINE1 expression is increased in colorectal cancer and in a highly proliferative colon cancer cell line and is related to tumor invasiveness and aggressiveness.

Altered expression of the clock gene machinery in kidney cancer patients

BACKGROUND AND AIM

Kidney cancer is associated with alteration in the pathways regulated by von Hippel-Lindau protein and hypoxia inducible factor α. Tight interrelationships have been evidenced between hypoxia response pathways and circadian pathways. The dysregulation of the circadian clock circuitry is involved in carcinogenesis. The aim of our study was to evaluate the clock gene machinery in kidney cancer.

METHODS

mRNA expression levels of the clock genes ARNTL1, ARNTL2, CLOCK, PER1, PER2, PER3, CRY1, CRY2, TIMELESS, TIPIN and CSNK1E and of the clock controlled gene SERPINE1 were evaluated by DNA microarray assays and by qRT-PCR in primary tumor and matched nontumorous tissue collected from a cohort of 11 consecutive kidney cancer patients.

RESULTS

In kidney tumor tissue, we found down-regulation of PER2 (median=0.658, Q1-Q3=0.562-0.744, P<0.01), TIMELESS (median=0.705, Q1-Q3=0.299-1.330, P=0.04) and TIPIN (median=0.556, Q1-Q3=0.385-1.945, P=0.01), up-regulation of SERPINE1 (median=1.628, Q1-Q3=0.339-4.071, P=0.04), whereas the expression of ARNTL2 (median=0.605, Q1-Q3=0.318-1.738, P=0.74) and CSNK1E (median=0.927, Q1-Q3=0.612-2.321, P=0.33) did not differ. A statistically significant correlation was evidenced between mRNA levels of PER2 and CSNKIE (r=0.791, P<0.01), PER2 and TIPIN (r=0.729, P=0.01), PER2 and SERPINE1 (r=0.704, P=0.01), TIMELESS and TIPIN (r=0.605, P=0.04), TIMELESS and CSNKIE (r=0.637, P=0.03), TIPIN and CSNKIE (r=0.940, P<0.01).

CONCLUSION

In kidney cancer, the circadian clock circuitry is deregulated and the altered expression of the clock genes might be involved in disease onset and progression.

D-glucuronyl C5-epimerase suppresses small-cell lung cancer cell proliferation in vitro and tumour growth in vivo

BACKGROUND

D-Glucuronyl C5-epimerase (GLCE) is a key enzyme involved in the biosynthesis of heparan sulphate proteoglycans, which has an important role in cell-cell and cell-matrix interactions and signalling. Decreased GLCE expression in human breast tumours and its anti-proliferative effects in breast cancer cells suggest that it may be a candidate tumour-suppressor gene. The aim of this study was to investigate the involvement of GLCE in lung carcinogenesis.

METHODS

D-Glucuronyl C5-epimerase expression in different lung cancer cell lines was determined and the gene was ectopically re-expressed in U2020 small-cell lung cancer cells. Cellular proliferation in vitro and tumour growth in vivo were then examined.

RESULTS

Ectopic re-expression of GLCE in U2020 cells did not affect cell viability but did influence morphology. Cellular proliferation in vitro and tumour formation in vivo were both suppressed. These effects were mediated via downregulation of several pro-angiogenic growth factors and their receptors, including VEGF-A, TGFB1, FGFR2, PDGF-A and PDGF-B, and TNFa and its receptors. Expression of matrix metalloproteinase2, MTA1, PLAU, TIMP3, S100A4, SERPINE1 and TWIST1 was also downregulated.

CONCLUSION

The anti-tumour effects associated with ectopic GLCE re-expression suggest that it may be a potential tumour-suppressor gene and a possible target for lung cancer diagnosis and treatment.

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.

Effects of specific chemical suppressors of plasminogen activator inhibitor-1 in cardiovascular diseases

INTRODUCTION

plasminogen activator inhibitor-1 (PAI-1) is critical in thrombus formation and inflammation. Although these are essential pathological features of cardiovascular diseases, the effects of PAI-1 inhibition against the development of cardiovascular remodeling have not been well studied.

AREAS COVERED

the review explores the therapeutic value of PAI-1 in the progression of various cardiovascular diseases. To date, the authors have reported that a novel PAI-1 inhibitor suppressed the development of experimental autoimmune myocarditis, vascular remodeling after arterial injury, and heart transplant rejection using rodent models. Pathologically, the PAI-1 inhibitor improved histological remodeling of myocardium and arteries with suppression of inflammation and thrombus formation.

EXPERT OPINION

PAI-1 inhibitors appear to exhibit potent effects on the prevention of adverse tissue remodeling. However, PAI-1 is a multifunctional protein and more research is needed to further elucidate the association between PAI-1 expression and cardiovascular disease.

IL-1beta induces expression of matrix metalloproteinase-9 and cell migration via a c-Src-dependent, growth factor receptor transactivation in A549 cells

BACKGROUND AND PURPOSE

Interleukin (IL)-1beta-induced matrix metalloproteinase (MMP-9) expression is regulated by mitogen activated protein kinases (MAPKs) and NF-kappaB. IL-1beta also stimulates transactivation of growth factor receptors and phosphatidylinositol 3-kinase (PI3K)/Akt., leading to the expression of inflammatory proteins. Here, we investigated whether these transactivation mechanisms participated in IL-1beta-induced MMP-9 expression in A549 cells.

EXPERIMENTAL APPROACH

A549 cells were treated with/without pharmacological inhibitors and neutralizing antibody or transfected with dominant negative mutants and siRNA of particular protein kinases before stimulation with IL-1beta. Cell migration was measured by in vitro scratch assay. Expression and enzymatic activity of MMP-9 were analysed by Western blot and gelatin zymography. Transcriptional activity of MMP-9 was analysed by RT-PCR, chromatin immunoprecipitation and promoter assays.

KEY RESULTS

Inhibition of MMP-9 expression by inhibitors of Src (PP1), platelet-derived growth factor (PDGF) receptor and epithelial growth factor (EGF) receptor or transfection with siRNA for Src and Akt prevented IL-1beta-induced migration of A549 cells. These tyrosine kinases were involved through phosphorylation of Src, PDGF, or EGF receptors (EGFRs) via the formation of Src/PDGFR or Src/EGFR complexes, attenuated by PP1. IL-1beta-induced MMP-9 expression through EGFR transactivation was diminished by inhibitors of MMPs and heparin-binding EGF-like factor (HB-EGF), or a neutralizing HB-EGF antibody. IL-1beta-stimulated activation and translocation of Akt and NF-kappaB (p65); the recruitment of activated NF-kappaB (p65) to the MMP-9 promoter region was attenuated by LY294002.

CONCLUSIONS AND IMPLICATIONS

IL-1beta-induced MMP-9 expression and cell migration was mediated through c-Src-dependent transactivation of EGFR/PDGFR/PI3K/Akt linking to the NF-kappaB pathway in A549 cells.

Interaction between lung cancer cells and astrocytes via specific inflammatory cytokines in the microenvironment of brain metastasis

The incidence of brain metastasis is increasing, however, little is known about molecular mechanism responsible for lung cancer-derived brain metastasis and their development in the brain. In the present study, brain pathology was examined in an experimental model system of brain metastasis as well as in human brain with lung cancer metastasis. In an experimental model, after 3–6 weeks of intracardiac inoculation of human lung cancer-derived (HARA-B) cells in nude mice, wide range of brain metastases were observed. The brain sections showed significant increase in glial fibrillary acidic protein (GFAP)-positive astrocytes around metastatic lesions. To elucidate the role of astrocytes in lung cancer proliferation, the interaction between primary cultured mouse astrocytes and HARA-B cells was analyzed in vitro. Co-cultures and insert-cultures demonstrated that astrocytes were activated by tumor cell-oriented factors; macrophage migration inhibitory factor (MIF), interleukin-8 (IL-8) and plasminogen activator inhibitor-1 (PAI-1). Activated astrocytes produced interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and interleukin-1 β (IL-1β), which in turn promoted tumor cell proliferation. Semi-quantitative immunocytochemistry showed that increased expression of receptors for IL-6 and its subunits gp130 on HARA-B cells. Receptors for TNF-α and IL-1β were also detected on HARA-B cells but down-regulated after co-culture with astrocytes. Insert-culture with astrocytes also stimulated the proliferation of other lung cancer-derived cell lines (PC-9, QG56, and EBC-1). These results suggest that tumor cells and astrocytes stimulate each other and these mutual relationships may be important to understand how lung cancer cells metastasize and develop in the brain.

DUSP1/MKP1 promotes angiogenesis, invasion and metastasis in non-small-cell lung cancer

DUSP1/MKP1 is a dual-specific phosphatase that regulates MAPKs activity, with an increasingly recognized role in tumor biology. To understand more about the involvement of DUSP1 in lung cancer, we performed gene expression analyses of parental and DUSP1-interfered H460 non-small-cell lung cancer (NSCLC) cells. Downregulation of DUSP1 induced changes in the expression levels of genes involved in specific biological pathways, including angiogenesis, MAP kinase phosphatase activity, cell-cell signaling, growth factor and tyrosine-kinase receptor activity. Changes in the expression of some of these genes were due to modulation of c-Jun-N-terminal kinase and/or p38 activity by DUSP1. Complementary functional assays were performed to focus on the implication of DUSP1 in angiogenesis and metastasis. In H460 cells, interference of DUSP1 resulted in a diminished capacity to invade through Matrigel, to grow tumors in nude mice and also to induce metastasis through tail-vein injection. Furthermore, the angiogenic potential of H460 cells was also impaired, correlating with a decrease in VEGFC production and indicating that DUSP1 could be required to induce angiogenesis. Finally, we studied whether a similar relationship occurred in patients. In human NSCLC specimens, DUSP1 was mainly expressed in those tumor cells close to CD31 vascular structures and a statistically significant correlation was found between VEGFC and DUSP1 expression. Overall, these results provide evidence for a role of DUSP1 in angiogenesis, invasion and metastasis in NSCLC.

Comparison of lung cancer cell lines representing four histopathological subtypes with gene expression profiling using quantitative real-time PCR

BACKGROUND

Lung cancers are the most common type of human malignancy and are intractable. Lung cancers are generally classified into four histopathological subtypes: adenocarcinoma (AD), squamous cell carcinoma (SQ), large cell carcinoma (LC), and small cell carcinoma (SC). Molecular biological characterization of these subtypes has been performed mainly using DNA microarrays. In this study, we compared the gene expression profiles of these four subtypes using twelve human lung cancer cell lines and the more reliable quantitative real-time PCR (qPCR).

RESULTS

We selected 100 genes from public DNA microarray data and examined them by DNA microarray analysis in eight test cell lines (A549, ABC-1, EBC-1, LK-2, LU65, LU99, STC 1, RERF-LC-MA) and a normal control lung cell line (MRC-9). From this, we extracted 19 candidate genes. We quantified the expression of the 19 genes and a housekeeping gene, GAPDH, with qPCR, using the same eight cell lines plus four additional validation lung cancer cell lines (RERF-LC-MS, LC-1/sq, 86-2, and MS-1-L). Finally, we characterized the four subtypes of lung cancer cell lines using principal component analysis (PCA) of gene expression profiling for 12 of the 19 genes (AMY2A, CDH1, FOXG1, IGSF3, ISL1, MALL, PLAU, RAB25, S100P, SLCO4A1, STMN1, and TGM2). The combined PCA and gene pathway analyses suggested that these genes were related to cell adhesion, growth, and invasion. S100P in AD cells and CDH1 in AD and SQ cells were identified as candidate markers of these lung cancer subtypes based on their upregulation and the results of PCA analysis. Immunohistochemistry for S100P and RAB25 was closely correlated to gene expression.

CONCLUSIONS

These results show that the four subtypes, represented by 12 lung cancer cell lines, were well characterized using qPCR and PCA for the 12 genes examined. Certain genes, in particular S100P and CDH1, may be especially important for distinguishing the different subtypes. Our results confirm that qPCR and PCA analysis provide a useful tool for characterizing cancer cell subtypes, and we discuss the possible clinical applications of this approach.

Inhibition of urokinase activity reduces primary tumor growth and metastasis formation in a murine lung carcinoma model

RATIONALE

Lung cancer is the most common malignancy in humans. Urokinase (uPA) plays a crucial role in carcinogenesis by facilitating tumor cell invasion and metastasis.

OBJECTIVES

We investigated the effect of the highly specific urokinase inhibitor CJ-463 (benzylsulfonyl-D-Ser-Ser-4-amidinobenzylamide) on tumor growth, metastasis formation, and tumor vascularization in the murine Lewis lung carcinoma (LLC) and a human small lung cancer model.

METHODS

A quantity of 3 x 10(6) LLC cells were subcutaneously injected into the right flank of C57Bl6/N mice, uPA knock out, and uPA receptor knockout mice. Seven days later mice were randomized to receive intraperitoneally either saline (control group), CJ-463 (10 and 100 mg/kg, twice a day), or its ineffective stereoisomer (10 mg/kg, twice a day). Tumor volume was measured every second day and metastasis formation was monitored by volumetric-computed tomography. Twelve days after onset of treatment mice were killed and tumors were prepared for histologic examination.

MEASUREMENTS AND MAIN RESULTS

Treatment with CJ-463 resulted in a significant inhibition of primary tumor growth, with the highest efficacy seen in the 100 mg/kg group. In addition, histological analysis of the lung revealed a significant reduction in lung micrometastasis in the 100 mg/kg group. Similarly, a reduced seeding of tumor cells into the lung after intravenous injection of LLC cells was observed in inhibitor-treated mice. In these mice, treatment with CJ-463 appeared not to significantly alter the relative extent of tumor vascularization. In vitro, proliferation of LLC cells remained unchanged upon inhibitor treatment. CJ-463 was found to similarly reduce tumor growth in uPA receptor knockout mice, but was ineffective in uPA knockout mice.

CONCLUSIONS

Our results suggest that synthetic low-molecular-weight uPA-inhibitors offer as novel agents for treatment of lung cancer.

Urokinase mediates endothelial cell survival via induction of the X-linked inhibitor of apoptosis protein

Urokinase-type plasminogen activator (uPA) additionally elicits a whole array of pro-angiogenic responses, such as differentiation, proliferation, and migration. In this study, we demonstrate that in endothelial cells uPA also protects against apoptosis by transcriptional up-regulation and partially by mRNA stabilization of inhibitor of apoptosis proteins, most prominently the X-linked inhibitor of apoptosis protein (XIAP). The antiapoptotic activity of uPA was dependent on its protease activity, the presence of uPA receptor (uPAR) and low-density lipoprotein receptor-related protein (LRP), but independent of the phosphatidylinositol 3 (PI3) kinase pathway, whereas vascular endothelial growth factor (VEGF)–induced antiapoptosis was PI3 kinase dependent. uPA-induced cell survival involved phosphorylation of p21-activated kinase 1 (Pak1) and the IκB kinase α that leads to nuclear factor κB (NF-κB) p52 activation. Indeed, blocking NF-κB activation by using specific NF-κB inhibitors abolished uPA-induced cell survival as it blocked uPA-induced XIAP up-regulation. Furthermore, down-regulating XIAP expression by small interfering RNA (siRNA) significantly reduced uPA-dependent endothelial cell survival. This mechanism is also important for VEGF-induced antiapoptosis because VEGF-dependent up-regulation of XIAP was found defective in uPA−/− endothelial cells. This led us to conclude that uPA is part of a novel NF-κB–dependent cell survival pathway.

Hypercoagulability and lung cancer

The relationship between cancer and coagulopathy was suggested by Trousseau nearly 150 years ago. Later, it became more evident that oncologic patients are at a higher risk of experiencing thromboembolic events. This can be due to activation of the coagulation system either by neoplastic cells or by prescribed therapies (chemotherapy or surgical procedures). In fact, these events can constitute the first manifestation of cancer, and their recurrence, despite efficient anticoagulation, has been described. The coagulation system is normally activated in order to provide healing. In the presence of neoplasms, this complex system is activated as a response to multiple stimuli and seems to contribute to cancer progression. Activation of the coagulation system has a greater effect on metastatic foci than on the primary tumor. However, most cancer victims die from complications caused by metastasis, which underscores the importance of this theme. In this area, various mechanisms have been described, creating promising perspectives for future treatments. The current success in using low-molecular-weight heparins against small cell lung cancer is encouraging. Although the knowledge of those mechanisms is relatively incipient, many basic research and clinical studies are underway.

Serum cathepsin B and plasma urokinase-type plasminogen activator levels in gastrointestinal tract cancers

Cathepsin B (CATB) and urokinase-type plasminogen activator (UPA) play an important part in cancer invasion and metastasis. The behavior of CATB and UPA has not been evaluated in the same experimental setting in different gastrointestinal tumors and in precancerous lesions. Serum CATB and plasma UPA levels were determined by enzyme-linked immunoadsorbent assay and their sensitivity, specificity, and diagnostic accuracy have been calculated in patients with colorectal (n=72), gastric (n=30), hepatocellular (n=28), and pancreatic cancer (n=15) as well as in gastric epithelial dysplasia (n=25), colorectal adenomas (n=30), and tumor-free control patients (n=44). Serum CATB and plasma UPA antigen concentrations were significantly higher in patients with cancer than in controls. When all tumors were considered, the sensitivity, specificity, and diagnostic accuracy of CATB (89, 86, and 89%) were higher than that of UPA (76, 70, and 74%). CATB demonstrated in all types of tumors a better diagnostic accuracy than UPA. The positive predictive values of CATB (95%) and UPA (89%) may suggest their use in the evaluation of patients with a suspicion of malignancy. CATB and UPA were significantly higher in patients with gastric epithelial dysplasia and colorectal adenomas than in controls. Antigen levels of CATB and UPA were significantly correlated in both cancers and precancerous lesions. At the time of clinical presentation, serum CATB and plasma UPA antigen levels are sensitive indicators of gastrointestinal malignancies. Determination of serum CATB and plasma UPA levels may be useful to identify patients at a higher risk for progression to cancer, who could be subjected to a more strict follow-up protocol.

Signaling through urokinase and urokinase receptor in lung cancer cells requires interactions with beta1 integrins

The urokinase receptor (uPAR) is upregulated upon tumor cell invasion and correlates with poor lung cancer survival. Although a cis-interaction with integrins has been ascribed to uPAR, whether this interaction alone is critical to urokinase (uPA)- and uPAR-dependent signaling and tumor promotion is unclear. Here we report the functional consequences of point mutations of uPAR (H249A-D262A) that eliminate beta1 integrin interactions but maintain uPA binding, vitronectin attachment and association with alphaV integrins, caveolin and epidermal growth factor receptor. Disruption of uPAR interactions with beta1 integrins recapitulated previously reported findings with beta1-integrin-derived peptides that attenuated matrix-dependent ERK activation, MMP expression and in vitro migration by human lung adenocarcinoma cell lines. The uPAR mutant cells acquired enhanced capacity to adhere to vitronectin via uPAR-alphaVbeta5-integrin, rather than through the uPAR-alpha3beta1-integrin complex and they were unable to initiate uPA signaling to activate ERK, Akt or Stat1. In an orthotopic lung cancer model, uPAR mutant cells exhibited reduced tumor size compared with cells expressing wild-type uPAR. Taken together, the results indicate that uPAR-beta1-integrin interactions are essential to signals induced by integrin matrix ligands or uPA that support lung cancer cell invasion in vitro and progression in vivo.

Tumor marker utility and prognostic relevance of cathepsin B, cathepsin L, urokinase-type plasminogen activator, plasminogen activator inhibitor type-1, CEA and CA 19-9 in colorectal cancer

BACKGROUND

Cathepsin B and L (CATB, CATL), urokinase-type plasminogen activator (uPA) and its inhibitor PAI-1 play an important role in colorectal cancer invasion. The tumor marker utility and prognostic relevance of these proteases have not been evaluated in the same experimental setting and compared with that of CEA and CA-19-9.

METHODS

Protease, CEA and CA 19-9 serum or plasma levels were determined in 56 patients with colorectal cancer, 25 patients with ulcerative colitis, 26 patients with colorectal adenomas and 35 tumor-free control patients. Protease, CEA, CA 19-9 levels have been determined by ELISA and electrochemiluminescence immunoassay, respectively; their sensitivity, specificity, diagnostic accuracy have been calculated and correlated with clinicopathological staging.

RESULTS

The protease antigen levels were significantly higher in colorectal cancer compared with other groups. Sensitivity of PAI-1 (94%), CATB (82%), uPA (69%), CATL (41%) were higher than those of CEA or CA 19-9 (30% and 18%, respectively). PAI-1, CATB and uPA demonstrated a better accuracy than CEA or CA 19-9. A combination of PAI-1 with CATB or uPA exhibited the highest sensitivity value (98%). High CATB, PAI-1, CEA and CA 19-9 levels correlated with advanced Dukes stages. CATB (P = 0.0004), CATL (P = 0.02), PAI-1 (P = 0.01) and CA 19-9 (P = 0.004) had a significant prognostic impact. PAI-1 (P = 0.001), CATB (P = 0.04) and CA 19-9 (P = 0.02) proved as independent prognostic variables.

CONCLUSION

At the time of clinical detection proteases are more sensitive indicators for colorectal cancer than the commonly used tumor markers. Determinations of CATB, CATL and PAI-1 have a major prognostic impact in patients with colorectal cancer.

Increased mortality in septic shock with the 4G/4G genotype of plasminogen activator inhibitor 1 in patients of white descent

OBJECTIVE

To evaluate the effect of the 4G/5G PAI-1 gene polymorphism on the development of organ failure and outcome in critically ill patients with septic syndromes.

DESIGN AND SETTING

Prospective, observational study in a medical intensive care unit of a university hospital.

PATIENTS

224 consecutively admitted patients.

INTERVENTIONS

Epidemiological data, severity scores, and the primary site of infection were recorded. DNA genotyping of the PAI-1, TNF-beta, and IL1-ra genes, and measurement of plasma PAI-1 antigen and D-dimer were carried out.

MEASUREMENTS

The primary outcome variables were organ dysfunction and mortality.

RESULTS

Eighty-eight subjects had septic shock at ICU entry or within 48 h from admission. Homozygotes for the 4G allele exhibited higher plasma concentrations of PAI-1 antigen and D-dimer than 4G/5G and 5G/5G subjects). ICU mortality was 44.0% in patients with 4G/4G, 23.4% in 4G/5G and 12.5% in 5G/5G, mainly due to multiorgan failure. After adjusting for SAPS II at admission the genotypes independently associated with ICU mortality in septic shock were TNF-B2/B2 (OR 2.83, 1.04-7.67) and 4G/4G of PAI-1 (OR 2.23, 1.02-4.85). The PAI-1 genotype did not determine susceptibility to infection or the outcome in nonseptic systemic inflammatory response syndrome, sepsis, severe sepsis, and nosocomial septic shock.

CONCLUSIONS

Homozygosity for 4G of the PAI-1 gene confers an increase in the risk of mortality in adult patients with septic shock due to a greater organ failure.