Cancer cells overexpress mRNA of urokinase-type plasminogen activator, its receptor and inhibitors in human non-small-cell lung cancer tissue: analysis by Northern blotting and in situ hybridization

PLAU promotes growth and attenuates cisplatin chemosensitivity in ARID1A-depleted non-small cell lung cancer through interaction with TM4SF1

Loss of ARID1A, a subunit of the SWI/SNF chromatin remodeling complex, contributes to malignant progression in multiple cancers including non-small cell lung cancer (NSCLC). In the search for key genes mediating the aggressive phenotype caused by ARID1A loss, we analyzed 3 Gene Expression Omnibus (GEO) datasets that contain RNA sequencing data from ARID1A-depleted cancer cells. PLAU was identified as a common gene that was induced in different cancer cells upon ARID1A depletion. Overexpression of PLAU positively modulated NSCLC cell growth, colony formation, cisplatin resistance, and survival under serum deprivation. Moreover, enforced expression of PLAU enhanced tumorigenesis of NSCLC cells in nude mice. Mechanistically, PLAU interacted with TM4SF1 to promote the activation of Akt signaling. TM4SF1-overexpressing NSCLC cells resembled those with PLAU overepxression. Knockdown of TM4SF1 inhibited the growth and survival and increased cisplatin sensitivity in NSCLC cells. The interaction between PLAU and TM4SF1 led to the activation of Akt signaling that endowed ARID1A-depleted NSCLC cells with aggressive properties. In addition, treatment with anti-TM4SF1 neutralizing antibody reduced the growth, cisplatin resistance, and tumorigenesis of ARID1A-depleted NSCLC cells. Taken together, PLAU serves as a target gene of ARID1A and promotes NSCLC growth, survival, and cisplatin resistance by stabilizing TM4SF1. Targeting TM4SF1 may be a promising therapeutic strategy for ARID1A-mutated NSCLC.

Recent Advances in Targeting the Urokinase Plasminogen Activator with Nanotherapeutics

The aberrant proteolytic landscape of the tumor microenvironment is a key contributor of cancer progression. Overexpression of urokinase plasminogen activator (uPA) and/or its associated cell-surface receptor (uPAR) in tumor versus normal tissue is significantly associated with worse clinicopathological features and poorer patient survival across multiple cancer types. This is linked to mechanisms that facilitate tumor cell invasion and migration, via direct and downstream activation of various proteolytic processes that degrade the extracellular matrix─ultimately leading to metastasis. Targeting uPA has thus long been considered an attractive anticancer strategy. However, poor bioavailability of several uPA-selective small-molecule inhibitors has limited early clinical progress. Nanodelivery systems have emerged as an exciting method to enhance the pharmacokinetic (PK) profile of existing chemotherapeutics, allowing increased circulation time, improved bioavailability, and targeted delivery to tumor tissue. Combining uPA inhibitors with nanoparticle-based delivery systems thus offers a remarkable opportunity to overcome existing PK challenges associated with conventional uPA inhibitors, while leveraging potent candidates into novel targeted nanotherapeutics for an improved anticancer response in uPA positive tumors.

Dynamic Plasma Lipidomic Analysis Revealed Cholesterol Ester and Amides Associated with Sepsis Development in Critically Ill Patients after Cardiovascular Surgery with Cardiopulmonary Bypass

Background: Sepsis in patients after cardiovascular surgery with cardiopulmonary bypass (CPB) has a high rate of mortality. We sought to determine whether changes in lipidomics can predict sepsis after cardiac surgery. Methods: We used high-performance liquid chromatography coupled to tandem mass spectrometry to explore global lipidome changes in samples from a prospective case-control cohort (30 sepsis vs. 30 nonsepsis) hospitalized with cardiovascular surgery. All patients were sampled before and within 48−72 h after surgery. A bioinformatic pipeline was applied to acquire reliable features and MS/MS-driven identifications. Furthermore, a multiple-step machine learning framework was performed for signature discovery and performance evaluation. Results: Compared with preoperative samples, 94 features were upregulated and 282 features were downregulated in the postoperative samples of the sepsis group, and 73 features were upregulated and 265 features were downregulated in the postoperative samples of the nonsepsis group. “Autophagy”, “pathogenic Escherichia coli infection” and “glycosylphosphatidylinositol-anchor biosynthesis” pathways were significantly enriched in the pathway enrichment analysis. A multistep machine learning framework further confirmed that two cholesterol esters, CE (18:0) and CE (16:0), were significantly decreased in the sepsis group (p < 0.05). In addition, oleamide and stearamide were increased significantly in the postoperative sepsis group (p < 0.001). Conclusions: This study revealed characteristic lipidomic changes in the plasma of septic patients before and after cardiac surgery with CPB. We discovered two cholesterol esters and two amides from peripheral blood that could be promising signatures for sepsis within a dynamic detection between the preoperative and postoperative groups.

DNA-coated gold nanoparticles for tracking hepatocyte growth factor secreted by transplanted mesenchymal stem cells in pulmonary fibrosis therapy

The identification of paracrine factors secreted by transplanted mesenchymal stem cells (MSCs) during the treatment of idiopathic pulmonary fibrosis (IPF) is essential for understanding the role of MSCs in therapy. Herein, we report a facile and efficient strategy for in vivo tracking the secretion of hepatocyte growth factor (HGF) in MSCs during IPF therapy. In our strategy, a novel nanoflare tracer consisting of gold nanoparticles (AuNPs), complementary sequences and dye-labeled recognition sequences is developed. Briefly, the AuNPs are functionalized with oligonucleotide complementary sequences hybridized to the organic dye-labeled recognition sequences, where the organic fluorophores are in close proximity to the AuNPs. In the absence of targets, the dye and AuNPs are separated from each other, inducing the quenching of the fluorescence signal. However, in the presence of targets, the recognition sequences gradually fall off from the AuNPs, causing the fluorescence signal to rise. In brief, in vivo monitoring of the dynamic expression of HGF mRNA in transplanted MSCs during IPF therapy in the current work may provide new insight into the paracrine process of the transplanted MSCs, thereby advancing the MSC-based IPF therapy toward clinical applications.

Poly-adenine-mediated fluorescent spherical nucleic acid probes for live-cell imaging of endogenous tumor-related mRNA

Identification of tumor-related mRNA in living cells hold great promise for early cancer diagnosis and pathological research. Herein, we present poly-adenine (polyA)-mediated fluorescent spherical nucleic acid (FSNA) probes for intracellular mRNA detection with regulable sensitivities by programmably adjusting the loading density of DNA on gold nano-interface. Gold nanoparticles (AuNPs) functionalized with polyA-tailed recognition sequences were hybridized to fluorescent "reporter" strands to fabricate fluorescence-quenched FSNA probes. While exposed to target gene, the "reporter" strands were released from FSNA through strand displacement and fluorescence was recovered. With polyA20 tail as the attaching block, the detection limit of FSNA probes was calculated to be 0.31 nM, which is ~55 fold lower than that of thiolated probes without surface density regulation. Quantitative intracellular mRNA detection and imaging could be achieved with polyA-mediated FSNA probes within 2 hours, indicating their application potential in rapid and sensitive intracellular target imaging.

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

Multiplexed detection of lung cancer biomarkers in patients serum with CMOS-compatible silicon nanowire arrays

In this work, a real-time assay for highly sensitive, label-free, multiplexed electrical detection of lung cancer biomarkers was developed by using silicon nanowire field-effect (SiNW-FET) devices. Highly responsive SiNW arrays were fabricated using a CMOS-compatible anisotropic self-stop etching technique with mass reproducibility and low cost character. The SiNW nanosensor was integrated with PDMS microfluidic device, which allows rapid analyte delivery, makes the analysis to be conducted using exceedingly small samples and enables potential multiplexed detection. The nanowire arrays allowed highly selective and sensitive multiplexed detection of microRNA (miRNA)-126 and CEA. Due to high surface-to-volume ratio that the nanowire dimensions confer, the detection floor of single molecule was achieved. The potential utility in identifying clinical samples for early diagnosis of cancer was demonstrated by analyzing biomarkers in clinical related samples. The developed nanosensor with capability for multiplexed real-time monitoring of biomarkers with high sensitivity and selectivity in clinically relevant samples is highly attractive for diagnosis and treatment of cancer and other diseases.

Exposure to airborne PM2.5 suppresses microRNA expression and deregulates target oncogenes that cause neoplastic transformation in NIH3T3 cells

Long-term exposure to airborne PM_2.5 is associated with increased lung cancer risk but the underlying mechanism remains unclear. We characterized global microRNA and mRNA expression in human bronchial epithelial cells exposed to PM_2.5 organic extract and integrally analyzed microRNA-mRNA interactions. Foci formation and xenograft tumorigenesis in mice with NIH3T3 cells expressing genes targeted by microRNAs were performed to explore the oncogenic potential of these genes. We also detected plasma levels of candidate microRNAs in subjects exposed to different levels of air PM_2.5 and examined the aberrant expression of genes targeted by these microRNAs in human lung cancer. Under our experimental conditions, treatment of cells with PM_2.5 extract resulted in downregulation of 138 microRNAs and aberrant expression of 13 mRNAs (11 upregulation and 2 downregulation). In silico and biochemical analyses suggested SLC30A1, SERPINB2 and AKR1C1, among the upregulated genes, as target for miR-182 and miR-185, respectively. Ectopic expression of each of these genes significantly enhanced foci formation in NIH3T3 cells. Following subcutaneous injection of these cells into nude mice, fibrosarcoma were formed from SLC30A1- or SERPINB2-expressing cells. Reduced plasma levels of miR-182 were detected in subjects exposed to high level of PM_2.5 than in those exposed to low level of PM_2.5 (P = 0.043). Similar results were seen for miR-185 although the difference was not statistically significant (P = 0.328). Increased expressions of SLC30A1, SERPINB2 and AKR1C1 were detected in human lung cancer. These results suggest that modulation of miR-182 and miR-185 and their target genes may contribute to lung carcinogenesis attributable to PM_2.5 exposure.

Plasminogen Activator System and Breast Cancer: Potential Role in Therapy Decision Making and Precision Medicine

Shifting from the historical TNM paradigm to the determination of molecular and genetic subtypes of tumors has been a major improvement to better picture cancerous diseases. The sharper the picture is, the better will be the possibility to develop subsequent strategies, thus achieving higher efficacy and prolonged survival eventually. Recent studies suggest that urokinase-type plasminogen activator (uPA), uPA Receptor (uPAR), and plasmino-gen activator inhibitor-1 (PAI-1) may 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 dismal prognosis. In this respect, upfront determination of uPA and PAI-1 as invasion markers has further opened up the possibilities for individualized therapy of breast cancer. Indeed, uPA and PAI-1 could help to classify patients on their risk for metastatic spreading and subsequent relapse, thus helping clinicians in their decision-making process to propose, or not propose, adjuvant therapy. This review covers the implications for cancer diagnosis, prognosis, and therapy of uPA and PAI-1, and therefore how they could be major actors in the development of a precision medicine in breast cancer.

Preparation and antitumor effect of a toxin-linked conjugate targeting vascular endothelial growth factor receptor and urokinase plasminogen activator

The aberrant signaling activation of vascular endothelial growth factor receptor (VEGFR) and urokinase plasminogen activator (uPA) is a common characteristic of many tumors, including lung cancer. Accordingly, VEGFR and uPA have emerged as attractive targets for tumor. KDR (Flk-1/VEGFR-2), a member of the VEGFR family, has been recognized as an important target for antiangiogenesis in tumor. In this study, a recombinant immunotoxin was produced to specifically target KDR-expressing tumor vascular endothelial cells and uPA-expressing tumor cells and mediate antitumor angiogenesis and antitumor effect. Based on its potent inhibitory effect on protein synthesis, Luffin-beta (Lβ) ribosome-inactivating protein was selected as part of a recombinant fusion protein, a single-chain variable fragment against KDR (KDRscFv)-uPA cleavage site (uPAcs)-Lβ-KDEL (named as KPLK). The KDRscFv-uPAcs-Lβ-KDEL (KPLK) contained a single-chain variable fragment (scFv) against KDR, uPAcs, Lβ, and the retention signal for endoplasmic reticulum proteins KDEL (Lys-Asp-Glu-Leu). The KPLK-expressing vector was expressed in Escherichia coli, and the KPLK protein was isolated with nickel affinity chromatography and gel filtration chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis test demonstrated KPLK was effectively expressed. Result of in vitro cell viability assay on non-small cell lung cancer (NSCLC) H460 cell line (uPA-positive cell) revealed that KPLK significantly inhibited cell proliferation, induced apoptosis, and accumulated cells in S and G2/M phases, but the normal cell line (human submandibular gland cell) was unaffected. These effects were enhanced when uPA was added to digest KPLK to release Lβ. For in vivo assay of KPLK, subcutaneous xenograft tumor model of nude mice were established with H460 cells. Growth of solid tumors was significantly inhibited in animals treated with KPLK up to 21 days, tumor weights were decreased, and the expression of angiogenesis marker CD31 was downregulated; meanwhile, the apoptosis-related protein casspase-3 was upregulated. These results suggested that the recombinant KPLK may have therapeutic applications on tumors, especially uPA-overexpressing ones.

Histones and their modifications in ovarian cancer - drivers of disease and therapeutic targets

Epithelial ovarian cancer has the highest mortality of the gynecological malignancies. High grade serous epithelial ovarian cancer (SEOC) is the most common subtype, with the majority of women presenting with advanced disease where 5-year survival is around 25%. Platinum-based chemotherapy in combination with paclitaxel remains the most effective treatment despite platinum therapies being introduced almost 40 years ago. Advances in molecular medicine are underpinning new strategies for the treatment of cancer. Major advances have been made by international initiatives to sequence cancer genomes. For SEOC, with the exception of TP53 that is mutated in virtually 100% of these tumors, there is no other gene mutated at high frequency. There is extensive copy number variation, as well as changes in methylation patterns that will influence gene expression. To date, the role of histones and their post-translational modifications in ovarian cancer is a relatively understudied field. Post-translational histone modifications play major roles in gene expression as they direct the configuration of chromatin and so access by transcription factors. Histone modifications include methylation, acetylation, and monoubiquitination, with involvement of enzymes including histone methyltransferases, histone acetyltransferases/deacetylases, and ubiquitin ligases/deubiquitinases, respectively. Complexes such as the Polycomb repressive complex also play roles in the control of histone modifications and more recently roles for long non-coding RNA and microRNAs are emerging. Epigenomic-based therapies targeting histone modifications are being developed and offer new approaches for the treatment of ovarian cancer. Here, we discuss histone modifications and their aberrant regulation in malignancy and specifically in ovarian cancer. We review current and upcoming histone-based therapies that have the potential to inform and improve treatment strategies for women with ovarian cancer.

Metastasis-associated factors facilitating the progression of colorectal cancer

Tumor metastasis remains the principal cause of treatment failure and poor prognosis in patients with colorectal cancer. It is a multistage process which includes proteolysis, motility and migration of cells, proliferation in a new site, and neoangiogenesis. A crucial step in the process of intra- and extra-vasation is the activation of proteolytic enzymes capable of degrading the extracellular matrix (ECM). In this stage, urokinase plasminogen activator receptor (uPAR) and matrix metalloproteinases (MMPs) are necessary. Micrometastases need the presence of growth factor and vascular growth factor so that they can form macrometastasis. In addition, cell adhesion molecules (CAMs) and guanine nucleotide exchange factors (GEFs) play important roles in the progression of colorectal cancer and metastatic migration. Further elucidation of the mechanisms of how these molecules contribute will aid in the identification of diagnostic and prognostic markers as well as therapeutic targets for patients with colorectal metastasis.

Regulation of u-PAR gene expression by H2A.Z is modulated by the MEK-ERK/AP-1 pathway

The urokinase receptor (u-PAR) which is largely regulated at the transcriptional level has been implicated in tumor progression. In this study, we explored the epigenetic regulation of u-PAR and showed that the histone variant H2A.Z negatively regulates its expression in multiple cell lines. Chromatin immunoprecipitation assays revealed that H2A.Z was enriched at previously characterized u-PAR-regulatory regions (promoter and a downstream enhancer) and dissociates upon activation of gene expression by phorbol ester (PMA). Using specific chemical and dominant negative expression constructs, we show that the MEK–ERK signaling pathway terminating at AP-1 transcription factors intersects with the epigenetic control of u-PAR expression by H2A.Z. Furthermore, we demonstrate that two other AP-1 targets (MMP9 gene and miR-21 microRNA) are also H2A.Z regulated. In conclusion, our work demonstrates that (i) the expression of two genes and a microRNA all implicated in tumor progression are directly regulated by H2A.Z and (ii) MEK–ERK signaling terminating at AP-1 intersects with the epigenetic control of target gene expression by H2A.Z.

Suppression on metastasis by rhubarb through modulation on MMP-2 and uPA in human A549 lung adenocarcinoma: an ex vivo approach

AIM OF THE STUDY

The aim of this study is to determine and identify the possible molecular mechanisms of anti-cancer effect of rhubarb under the physiologically achievable concentrations by using an ex vivo approach.

MATERIALS AND METHODS

Rats were orally administered rhubarb decoction and then serum metabolites were extracted, prepared and characterized to assay for the following in vitro study. The MTT assay, zymography analysis, wound healing assay, RT-PCR, and Western blot analysis were used to reveal molecular events of rhubarb metabolites in this study. Experimental metastasis model was used to investigate the in vivo anti-metastatic efficacy of rhubarb.

RESULTS

Our results demonstrated that cell line mobility was strongly inhibited and the enzymatic activity of MMP-2 decreased following culture with the rhubarb serum metabolite in human lung adenocarcinoma A549 cells. Further experiments demonstrated that the downregulation of MMP-2 enzymatic activity act through both transcriptional and post-translational mechanisms. NF-κB/c-Jun and uPA were observed involving in the inhibition of MMP-2 transcription and post-translational modification, respectively, in A549 cells treated with rhubarb serum metabolite. Further animal experiments demonstrated a significant reduction in lung metastatic colonies in rhubarb-treated mice, suggesting that rhubarb contain enriched active components that block cancer metastasis.

CONCLUSIONS

Our studies, both in vitro and in vivo, clearly demonstrated the anti-tumor effect of rhubarb in an experimental setting of achievable physiological concentrations and also provide possible molecular mechanisms of anti-metastatic mechanisms by rhubarb treatment.

Translational research on u-PAR

The urokinase receptor (u-PAR) is one of the most critical molecules in migration, invasion, intravasation, and metastasis and is also a key regulator between tumour cell proliferation and dormancy. It is overexpressed in most human solid cancer types, which has led to increasing translational and clinical research on this molecule. The current review discusses in particular the in vivo, translational, and putative clinical relevance of u-PAR in the context of this latest development. It outlines how u-PAR is already being used and might increasingly be applied as a diagnostic tool, for example, in distinguishing benign from malignant neoplasms, as a molecular marker for predicting clinical response to chemotherapy or novel targeted therapy, and finally as a promising tool for the development of novel cancer therapeutics.

Pdcd4, a colon cancer prognostic that is regulated by a microRNA

The novel tumor suppressor Pdcd4 inhibits neoplastic transformation, tumor progression and translation. Furthermore, we and others have recently shown that Pdcd4 suppresses invasion and intravasation, at least in part by suppressing expression of the invasion-related urokinase receptor (u-PAR) gene via the transcription factors Sp1/Sp3. Nevertheless, relatively little is known about mechanisms that regulate Pdcd4 expression in cancer. MicroRNAs (miRNAs) have been recently discovered and shown to be naturally occurring non-coding RNAs that control gene expression via specific sites within the 3'UTR of target miRNAs. This short review will focus on our recent finding that the microRNA miR-21 posttranscriptionally regulates Pdcd4, as well as invasion, intravasation, and metastasis. Furthermore, we will review the first translational and clinical results concerning the prognostic value of Pdcd4, in particular our own data that show Pdcd4 to be a novel and independent prognostic factor in colorectal cancer, and a potential supportive diagnostic tool for discriminating normal colonic tissues from benign adenomas and colorectal carcinomas.

Urokinase expression in course of benign and malignant mammary lesions: comparison between nodular and healthy tissues

PURPOSE

Increased expression of urokinase (uPA), a member of the serine protease family, is an effector of metastatic cascade and has been reported in various malignancies, including breast cancer. uPA overexpression in cancer tissues was correlated with a more aggressive phenotype and it is considered a strong and independent unfavorable prognostic factor in breast cancer.

METHODS

Using real-time PCR assay, we analyzed uPA expression of malignant and benign breast nodular lesions versus healthy tissues (normal breast and lymphocytes).

RESULTS

We found that besides breast cancer nodule, normal mammary gland and lymphocytes overexpressed uPA too. Tissues obtained from women with benign lesions expressed homogeneous and lower uPA.

CONCLUSIONS

In conclusion, although uPA overexpression is typical of cancer tissues, it could be considered as a feature of the whole organism affected by cancer. On the basis of these first results, uPA could be considered for further studies as a possible useful therapeutic target in breast cancer.

The urokinase receptor (u-PAR)--a link between tumor cell dormancy and minimal residual disease in bone marrow?

Minimal residual disease (MRD) is hypothesized to be the major cause of tumor recurrence and metastasis even years and decades after primary cancer diagnosis and curative solid tumor resection. In these patients disseminated tumor cells reflecting MRD can be detected in the bone marrow years after treatment. It is to be assumed that genetic determinants and a complex interplay between the disseminated tumor cells and their microenvironment in the bone marrow are responsible for tumor cell dormancy and the final reactivation towards metastasis. The urokinase receptor (u-PAR), a critical regulator of invasion, intravasation, and metastasis, is found to be a key player in regulating the shift between single cell tumor dormancy and proliferation. This has mainly been attributed to a regulation by u-PAR of integrins, and the ability of the latter to propagate signals from fibronectin through the EGF-receptor, ERK, and p38 signaling. Interestingly, u-PAR is found in disseminated tumor cells in the bone marrow of solid cancer patients, and is associated with the expansion of these cells and clinical prognosis. Here we summarize and discuss findings on disseminated tumor cells in the bone marrow, MRD and the role of u-PAR in tumor biology, especially focusing on its specific role in providing a switch between tumor cell proliferation and dormancy. Finally, we discuss the hypothesis that u-PAR might be an essential molecule in bone marrow disseminated tumor cells for long-term survival during dormancy, and/or reactivation of their proliferation years after primary treatment.

Tumour cell expression of C4.4A, a structural homologue of the urokinase receptor, correlates with poor prognosis in non-small cell lung cancer

PURPOSE

C4.4A expression has been implicated in human cancer progression. This protein is a structural homologue of the urokinase receptor, uPAR, which constitutes a well-established prognostic marker in various human cancers. Nonetheless, little is known about the prognostic significance of C4.4A expression. In the present study, we therefore explored the possible association between C4.4A expression and prognosis in patients with non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

Tissue sections from 108 NSCLC patients were subjected to immunohistochemical staining using a polyclonal antibody that specifically recognises human C4.4A. Staining frequency and intensity was scored semiquantitatively and grouped into cancers with high and low expression of C4.4A. Kaplan-Meier survival curves were generated to evaluate the significance of C4.4A expression in prognosis of NSCLC patients.

RESULTS

High C4.4A expression was observed in 42% of the NSCLC specimens analysed, and this correlates with overall survival (p = 0.012). A remarkably strong correlation was noted between high expression of C4.4A in pulmonary adenocarcinoma and survival (p < 0.0001). Multivariate Cox regression analysis shows that high C4.4A expression is an independent predictor of poor disease outcome in NSCLC (risk ratio, 1.42; 95% confidence interval, 1.09-1.86; p = 0.009). Although histological type is not a predictor of outcome in NSCLC, high C4.4A expression in adenocarcinoma is nevertheless a very strong predictor of poor disease outcome (risk ratio, 1.62; 95% confidence interval, 1.24-2.09; p = 0.001).

CONCLUSIONS

High tumour cell C4.4A expression is associated with shorter survival for NSCLC patients. Patients with pulmonary adenocarcinoma have a particularly poor prognosis if this histological type is combined with high tumour cell C4.4A expression.

Antimetastatic activity of insulin-like growth factor binding protein-3 in lung cancer is mediated by insulin-like growth factor-independent urokinase-type plasminogen activator inhibition

Insulin-like growth factor binding protein-3 (IGFBP-3), a major IGF-binding protein in human serum, regulates the growth of non-small cell lung cancer (NSCLC) cells through IGF-dependent and IGF-independent mechanisms. However, the role of IGFBP-3 in lung cancer metastasis is not well known. In the present study, we showed that noncytotoxic doses of adenoviral or recombinant IGFBP-3 significantly decreased the migration and invasion of H1299 and A549 NSCLC cells. Furthermore, treatment of human lung fibroblasts with recombinant IGFBP-3 suppressed their ability to stimulate the invasion of H1299 cells. Overexpression of IGFBP-3 markedly reduced lung metastasis of A549 cells in an experimental animal model system and prolonged the survival time of the animals. Urokinase-type plasminogen activator (uPA) inhibitor treatment or uPA small interfering RNA transfection of A549 and H1299 cells resulted in a significant decrease in invasion. Corresponding ELISA, Western blot, gelatin zymogram, and semiquantitative reverse transcription-PCR analyses revealed that IGFBP-3 reduced the expression of uPA mRNA through IGF-independent mechanisms. The specific role of uPA in anti-invasive activity of IGFBP-3 was further confirmed in NSCLC cells, in which uPA expression/activity was suppressed by the transfection with synthetic small interfering RNA or by the treatment with uPA inhibitor or induced by the infection with an adenoviral vector. IGFBP-3 also decreased the expression/activity of matrix metalloproteinase-2 through IGF-dependent but uPA-independent pathways. Taken together, our data suggest that IGFPB-3 effectively block uPA- and matrix metalloproteinase-2-stimulated invasion pathways, ultimately reducing lung cancer cell metastasis. Our findings indicate that IGFBP-3 may be a promising anti-invasive and antimetastatic therapeutic agent in lung cancer.

Molecular regulation of an invasion-related molecule – options for tumour staging and clinical strategies

This review provides a summary of the European Association for Cancer Research Award Lecture, presented at the ECCO13 meeting in Paris in November 2005. It is a brief overview on the biological and clinical relevance of the urokinase receptor (u-PAR), an essential molecule to promote invasive and metastatic tumour phenotype and shown to be associated with early relapse and poor prognosis in many different types of cancers. The review summarizes the most important transcriptional mechanisms regulating u-PAR gene, and will focus on the differential binding of transcription factors to u-PAR promoter elements from studies in resected tumour and normal tissues of colorectal and gastric cancer patients. These studies conducted by our group may help to understand transcriptional mechanisms, which are employed to promote invasion and metastasis, in subpopulations of cancer patients. Such studies could lead to a more target-oriented patient selection and therapy against transcriptional and oncogeneic regulators in cancer.

A novel 3-dimensional culture system as an in vitro model for studying oral cancer cell invasion

Tissue microenvironment plays a critical role in tumour growth and invasion. This study established a novel 3-dimensional (3-D) cell invasion model for direct microscopic observation of oral cancer cell invasion into the underlying basement membrane and connective tissue stroma. A multilayer cell construct was developed using the OptiCell chamber, consisting of a lower layer of oral mucosa fibroblasts embedded in collagen gel and an overlaying upper layer of oral cancer cells. The two layers are separated by a basement membrane composed of reconstituted extracellular matrix. To verify the applicability of the cell invasion model, multilayer cell constructs of oral squamous cell carcinoma and oral mucosal fibroblasts were exposed to extrinsic urokinase-type plasminogen activator (uPA) or plasminogen activator inhibitor (PAI-1), which are known effectors of cell migration. In addition, the constructs were exposed to both normoxic and hypoxic culture conditions. Microscopic study showed that the presence of uPA enhanced cell invasion, while PAI-1 inhibited cell migration. Western blot and zymographic analysis demonstrated that hypoxia up-regulated uPA and matrix metalloproteinases (MMPs) expression and activity; conversely, PAI-1 level was down-regulated in response to hypoxic challenge as compared to normoxic condition. Our results indicated that the novel 3-D invasion model could serve as an excellent in vitro model to study cancer cell invasion and to test conditions or mediators of cellular migration.

Sexual dimorphism in endotoxin susceptibility after partial hepatectomy in rats

BACKGROUND/AIMS

Liver failure due to endotoxemia after hepatectomy is a fatal complication. Little is known regarding the gender influence on this pathophysiological condition. This study was conducted to investigate whether a gender difference exists in the endotoxin susceptibility after hepatectomy.

METHODS

Sexually mature male and female rats received an intravenous administration of lipopolysaccharide (LPS), as endotoxin, 48h after a two-thirds hepatectomy.

RESULTS

The 24-h survival rate after LPS administration was significantly higher in females (75%) than in males (38%). Ovariectomy reduced the survival rate in females to 44%. Plasma tumor necrosis factor-alpha levels 1h after LPS were significantly elevated in males and ovariectomized females. The inducible nitric oxide synthase (iNOS) gene expression in liver and spleen, and consequent nitric oxide production 3h after LPS were significantly enhanced in males and ovariectomized females when compared to females, in addition to less functional and structural liver damage in females.

CONCLUSIONS

Our results indicate a gender difference in the susceptibility to endotoxemia in the early phase after hepatectomy. Female tolerance to these conditions may be mediated by an inhibition of excessive inflammatory response in the liver and the spleen, partially via the suppression of iNOS gene up-regulation.

Recombinant immunotoxins for the treatment of haematological malignancies

Recombinant immunotoxins are fusion proteins which contain a ligand derived from the immune system fused to a toxin. The protein toxin is truncated to delete its binding domain, allowing selective ligand-directed binding. Growth factor fusion toxins are often considered immunotoxins. One of these molecules, containing the truncated diphtheria toxin and human IL-2 (Ontak), Ligand Pharmaceuticals), has been approved for the treatment of cutaneous T-cell lymphoma. Recombinant immunotoxins have also been produced containing the variable domains (Fv fragment) of monoclonal antibodies fused to toxins. These agents are relatively versatile with respect to the range of antigens possible. Several of these recombinant immunotoxins have showed clinical effectiveness in Phase I testing against haematological malignancies. One of these molecules, BL22, targets CD22 on hairy-cell leukaemia and has enabled patients to achieve complete remissions despite previous treatment and resistance to chemotherapy.

Increased plasma levels of urokinase plasminogen activator and matrix metalloproteinase-9 in nonsmall cell lung cancer patients

BACKGROUND

The involvements of matrix metalloproteinase-9 (MMP-9) and urokinase plasminogen activator (uPA) in the pathogenesis of various types of lung cancers have been established. The aim of the present study was to determine the concentrations of MMP-9 and uPA in the plasma of nonsmall cell lung cancer (NSCLC) patients.

METHODS

Gelatin zymography and ELISA were used to measure MMP-9 and uPA concentrations, respectively, in 90 NSCLC patients and 50 control subjects.

RESULTS

Compared with that of control subjects, MMP-9 and uPA levels were significantly higher in the plasma of NSCLC patients (P<0.001 and P<0.01, respectively). Further statistical analysis for clinic pathological parameters revealed that MMP-9 and uPA levels were significantly increased in patients with metastasis (P<0.01 and P<0.05, respectively). Furthermore, the MMP-9 level was significantly different between smokers and nonsmokers (P<0.05) while uPA levels varied between histological types (P<0.05).

CONCLUSIONS

Plasma MMP-9 and uPA might play an important role in the metastasis of NSCLC by involvement in the processes of invasion and metastasis.

Clinical significance of urokinase-type plasminogen activator receptor (uPAR) expression in cancer

The involvement of the urokinase-type plasminogen activator (uPA) system in particular has been extensively studied in the pathogenesis of cancer. The molecular role of the uPA receptor (uPAR) is well characterized with its participation in cell migration and extracellular matrix (ECM) degradation. Over-expression of uPAR in cancer has been demonstrated in many studies and is considered an attractive target for anticancer agents. We and others have down-regulated uPAR expression in an attempt to inhibit cancer metastasis based on its molecular role. Uniquely, uPAR which is a glycosyl phosphatidylinositol anchored protein is not only bound to the cell surface but also has a soluble form, suPAR. There is now accumulated clinical and experimental evidence supporting the significant role of uPAR and its soluble counterpart in a number of solid cancers. The expression of uPAR can be associated with tumor cells or stromal cells or both. Differences observed in the expression of uPAR using immunohistochemistry (IHC) are likely explained by the use of different antibodies and techniques rather than true cellular differences and are reviewed here. This review summarizes the clinical relevance of uPAR and its soluble form in the prognosis and diagnosis of different cancers.

Pretreatment determination of the serum urokinase plasminogen activator and its soluble receptor in advanced small-cell lung cancer or non-small-cell lung cancer

This study was undertaken to evaluate the circulating urokinase plasminogen activator (uPA), and its soluble receptor (suPAR) in patients with either small-cell lung cancer (SCLC) or non-small-cell lung cancer (NSCLC). Thirty-one male and female patients with stage III or IV NSCLC and 17 with stage III or IV SCLC were compared to 138 age-matched non-smoking controls of both sexes. Before any treatment was undertaken, serum was obtained and evaluated for its content of uPA and suPAR with enzyme-linked immunosorbent assay. The results indicated a wide variation in serum uPA content that was not significant, while extremely significant increases in suPAR were found. The natural physiologic relationship between uPA and its receptor was lost in both SCLC and NSCLC, which could indicate abnormal alterations of uPA suPAR, suggesting these factors aid in the process of invasion and metastasis of lung cancer.

Molecular regulation of urokinase-receptor gene expression as one potential concept for molecular staging and therapy

The urokinase-receptor (u-PAR) is a central molecule of invasion and metastasis promoting plasminogen-dependent extracellular matrix degradation in diverse carcinoma types such as gastric or colon cancer. Overexpression of u-PAR has been reported to occur mainly at the transcriptional level in malignant cells, and has been shown to indicate a poor clinical prognosis of cancer patients. This review will give an overview on experimental findings on u-PAR and its function, molecular mechanisms of its regulation, and its impact for future clinical decision planning and potential therapeutic concepts.

Transcriptional regulation of the urokinase receptor (u-PAR)--a central molecule of invasion and metastasis

The phenomenon of tumor-associated proteolysis has been acknowledged as a decisive step in the progression of cancer. This short review focuses on the urokinase receptor (u-PAR), a central molecule involved in tumor-associated invasion and metastasis, and summarizes the transcriptional regulation of u-PAR. The urokinase receptor (u-PAR) is a heavily glycosylated cell surface protein and binds the serine protease urokinase specifically and with high affinity. It consists of three similar cysteine-rich repeats and is anchored to the cell membrane via a GPI-anchor. The u-PAR gene comprises 7 exons and is located on chromosome 19q13. Transcriptional activation of the u-PAR promoter region can be induced by binding of transcription factors (Sp1, AP-1, AP-2, NF-kappa B). One current study gives an example for transcriptional downregulation of u-PAR through a PEA3/ets transcriptional silencing element. Knowledge of the molecular regulation of this molecule in tumor cells could be very important for diagnosis and therapy in the near future.

Construction of antisense RNA expression plasmid for u-PAR and its transfection to highly invasive PC-3M cell subclones

To evaluate the specific inhibition of antisense u-PAR on the u-PAR expressions in highly invasive cell subclones and to determine its blocking function in the invasion by those cells, a cDNA fragment of u-PAR obtained by RT-PCR was inserted into a plasmid vector named pcDNA3 in antisense orientation. Then the antisense u-PAR recombinant was transfected into highly invasive cell subclones. The u-PAR expression in neo-resistant cells was examined by RT-PCR and immunohistochemical assay. Compared to the control cells, the content of mRNA and protein of u-PAR in transfected cells decreased sharply, and the rate of inhibition was 53% and 73%, respectively, indicating that an antisense u-PAR might have played a specific inhibitory role in its expression in the cells, which may provide a good cell model for making further investigation of the inhibitory effects of the antisense u-PAR on invasion in highly invasive cell subclones of human prostate carcinoma.

Plasminogen promotes sarcoma growth and suppresses the accumulation of tumor-infiltrating macrophages

The specific functions of plasminogen, stromal plasminogen activator, stromal plasminogen activator receptor, and stromal plasminogen activator inhibitor in the progression of the murine soft tissue sarcoma, T241 were investigated. Negation of plasminogen to the tumor blunted the orthotopic growth of the sarcoma in syngeneic mice. The reduced tumor growth was associated with a dramatic increase in tumor-infiltrating F4/80-positive macrophages and a diminution of vessel density, but not with obvious differences in fibrin and collagen deposition, or invasiveness of the tumor. Ablation of plasminogen activation by the tumor stroma only modestly impaired the prolonged growth of the sarcoma, suggesting that tumor cell-produced plasminogen activator is sufficient to mediate productive plasminogen activation. Plasminogen facilitated sarcoma progression, angiogenesis, and suppression of macrophage infiltration in the absence of either stromal urokinase plasminogen activator receptor or stromal plasminogen activator inhibitor. These data demonstrate that tumor cell-produced plasminogen activator and host plasminogen cooperate to facilitate soft tissue sarcoma growth and suppress the accumulation of tumor-infiltrating macrophages.

Hypoxia enhances the expression of plasminogen activator inhibitor-1 in human lung cancer cells, EBC-1

Plasminogen activator inhibitor-1 (PAI-1) is one of the target genes of hypoxia inducible factor-1alpha (HIF-1alpha). Besides being an important physiological regulator of the fibrinolytic system PAI-1 is also involved in cancer invasiveness. HIF-1alpha is expressed in various types of pulmonary cells, but the relation of PAI-1 to HIF-1alpha under hypoxic condition in these cells are not fully elucidated. We, therefore, studied the effect of hypoxia on the expression of PAI-1 in a lung cancer cell line EBC-1. The expression of HIF-1alpha protein in EBC-1 cells was enhanced by hypoxia, and this was associated with increased secretion of PAI-1. Hypoxia did not affect the levels of HIF-1alpha mRNA but enhanced the PAI-1 mRNA. Pretreatment of the cells with MG132, which inhibits the proteasomal degradation of HIF-1alpha, increased the production of PAI-1 under both normoxia and hypoxia. We conclude that hypoxia induces PAI-1 expression, in EBC-1 cells, through the stabilization of HIF-1 complex and this may be related to cancer metastasis.

Regulation of activator protein-1 activity in the mediastinal lymph node metastasis of lung cancer

Orthotopic implantation of a metastatic cell line of Lewis lung carcinoma (LLC-MLN), which was isolated by an in vivo selection method, resulted in greater metastatic growth in mediastinal lymph nodes as compared with that of the original LLC cells. LLC-MLN cells also had increased invasive ability and activator protein-1 (AP-1) transcriptional activity as compared with the original LLC cells. This is well consistent with the previously reported finding that overexpression of AP-1 is associated with lymphatic metastasis in lung cancer patients. Oral administration of curcumin, which downregulates AP-1 transcription, significantly inhibited the mediastinal lymph node metastasis of orthotopically implanted LLC cells in a dose-dependent manner, but did not affect the tumor growth at the implantation site. Combined treatment with curcumin and an anti-cancer drug, cis-diamine-dichloroplatinum (CDDP), resulted in a marked inhibition of tumor growth at the implanted site and of lymphatic metastasis, and a significant prolongation of the survival time. The downregulation of transcriptional AP-1 activity by curcumin as seen in the dual luciferase assay caused inhibition of LLC cell invasion through the repression of expression of the mRNAs for urokinase-type plasminogen activator (u-PA) and its receptor (u-PAR). Inhibition of AP-1 transcriptional activity may offer improved therapeutic efficacy for lung cancer patients with lymphatic metastasis.

Species specificity of amidine-based urokinase inhibitors

Inhibition of the proteolytic activity of urokinase has been shown to inhibit the progression of tumors in rodent models and is being investigated for use in human disease. Understanding the rodent/human species-specificity of urokinase inhibitors is therefore critical for interpretation of rodent cancer progression models that use these inhibitors. We report here studies with a panel of 11 diverse urokinase inhibitors in both human and mouse enzymatic assays. Inhibitors such as amiloride, B428, and naphthamidine, that occupy only the S1 subsite pocket were found to be nearly equipotent between the human and the murine enzymes. Inhibitors that access additional, more distal, pockets were significantly more potent against the human enzyme but there was no corresponding potency increase against the murine enzyme. X-ray crystallographic structures of these compounds bound to the serine protease domain of human urokinase were solved and examined in order to explain the human/mouse potency differences. The differences in inhibitor potency could be attributed to four amino acid residues that differ between murine and human urokinases: 60, 99, 146, and 192. These residues are Asp, His, Ser, and Gln in human and Gln, Tyr, Glu, and Lys in mouse, respectively. Compounds bearing a cationic group that interacts with residue 60 will preferentially bind to the human enzyme because of favorable electrostatic interactions. The hydrogen bonding to residue 192 and steric considerations with residues 99 and 146 also contribute to the species specificity. The nonparallel human/mouse enzyme inhibition observations were extended to a cell-culture assay of urokinase-activated plasminogen-mediated fibronectin degradation with analogous results. These studies will aid the interpretation of in vivo evaluation of urokinase inhibitors.

In vitro modulation of human lung cancer cell line invasiveness by antisense cDNA of tissue factor pathway inhibitor-2

Human tissue factor pathway inhibitor-2 (TFPI-2) is a Kunitz-type serine protease inhibitor that inhibits plasmin, trypsin, chymotrypsin, cathepsin G and plasma kallikrein but not urokinase (uPA) or tissue-type plasminogen activator and thrombin. Earlier studies from our and other laboratories have shown that the production of TFPI-2 is downregulated during the progression of various cancers. To investigate the role of TFPI-2 in the invasion and metastasis of lung tumors, the human lung cancer cell line A549, which produces high levels of TFPI-2, was stably transfected with a vector capable of expressing an antisense transcript complementary to the full-length TFPI-2 mRNA. Northern blot analysis was used to quantify the TFPI-2 mRNA transcript, and western blot analysis was used to measure TFPI-2 protein levels in parental cells and stably transfected (vector and antisense) clones. The levels of TFPI-2 mRNA and protein were significantly less in antisense clones than in the parental and vector controls. The invasive potential of the parental cells and stably transfected vector clones in vitro, as measured by the Matrigel invasion assay, was also markedly less than that of antisense clones. Further characterization of these clones showed that more cells migrated from antisense clones than from parental and vector clones. These data suggest that TFPI-2 is critical for the invasion and metastasis of lung cancer and that the downregulation of TFPI-2 production may be a feasible approach to increase invasiveness and metastasis.

Targeting of tumor cells by cell surface urokinase plasminogen activator-dependent anthrax toxin

Urokinase plasminogen activator receptor (uPAR) binds pro-urokinase plasminogen activator (pro-uPA) and thereby localizes it near plasminogen, causing the generation of active uPA and plasmin on the cell surface. uPAR and uPA are overexpressed in a variety of human tumors and tumor cell lines, and expression of uPAR and uPA is highly correlated to tumor invasion and metastasis. To exploit these characteristics in the design of tumor cell-selective cytotoxins, we constructed mutated anthrax toxin-protective antigen (PrAg) proteins in which the furin cleavage site is replaced by sequences cleaved specifically by uPA. These uPA-targeted PrAg proteins were activated selectively on the surface of uPAR-expressing tumor cells in the presence of pro-uPA and plasminogen. The activated PrAg proteins caused internalization of a recombinant cytotoxin, FP59, consisting of anthrax toxin lethal factor residues 1-254 fused to the ADP-ribosylation domain of Pseudomonas exotoxin A, thereby killing the uPAR-expressing tumor cells. The activation and cytotoxicity of these uPA-targeted PrAg proteins were strictly dependent on the integrity of the tumor cell surface-associated plasminogen activation system. We also constructed a mutated PrAg protein that selectively killed tissue plasminogen activator-expressing cells. These mutated PrAg proteins may be useful as new therapeutic agents for cancer treatment.

Dedifferentiation of serous ovarian cancer from cystic to solid tumors is associated with increased expression of mRNA for urokinase plasminogen activator (uPA), its receptor (uPAR) and its inhibitor (PAI-1)

The plasminogen activating system is involved in tumor growth and metastasis by degradation of extracellular matrix, and modulation of cell adhesion and migration. Benign and well-differentiated malignant ovarian tumors present as cystic lesions with preserved glandular morphology, whereas poorly differentiated tumors and metastases are solid with characteristic absence of glandular morphology. We analyzed the mRNAs for urokinase plasminogen activator (uPA), its receptor (uPAR), and inhibitor (PAI-1) in serous ovarian tumors by in situ hybridization and by densitometric scanning of Northern blots prepared from tissue extracts. The mRNA expressing cells in the in situ hybridization sections were evaluated and counted by two different observers. The number of mRNA expressing cells for uPA, uPAR and PAI-1 were all significantly increased in solid as compared with cystic malignant tumors. The increased expression of all three mRNA species was mainly located in the stroma of poorly differentiated tumors and metastases. Apart from being expressed in the stroma of these tumors, uPAR mRNA was also expressed by tumor cells located along the stromal/epithelial boarder. In addition, the tumor tissue content of uPA, uPAR and PAI-1 mRNAs as measured by Northern blots were higher in the solid as compared with the cystic tumors. Increased expression of uPA, uPAR and PAI-1 genes in the solid tumors suggest a correlation with a more aggressive phenotype.

Down-regulation of glycosylphosphatidylinositol-specific phospholipase D induced by lipopolysaccharide and oxidative stress in the murine monocyte- macrophage cell line RAW 264.7

Serum glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD) activity is reduced over 75% in systemic inflammatory response syndrome. To investigate the mechanism of this response, expression of the GPI-PLD gene was studied in the mouse monocyte-macrophage cell line RAW 264.7 stimulated with lipopolysaccharide (LPS; 0.5 to 50 ng/ml). GPI-PLD mRNA was reduced approximately 60% in a time- and dose-dependent manner. Oxidative stress induced by 0.5 mM H(2)O(2) or 50 microM menadione also caused a greater than 50% reduction in GPI-PLD mRNA. The antioxidant N-acetyl-L-cysteine attenuated the down-regulatory effect of H(2)O(2) but not of LPS. Cotreatment of the cells with actinomycin D inhibited down-regulation induced by either LPS or H(2)O(2). The half-life of GPI-PLD mRNA was not affected by LPS, or decreased slightly with H(2)O(2), indicating that the reduction in GPI-PLD mRNA is due primarily to transcriptional regulation. Stimulation with tumor necrosis factor alpha (TNF-alpha) resulted in approximately 40% reduction in GPI-PLD mRNA in human A549 alveolar carcinoma cells but not RAW 264.7 cells, suggesting that alternative pathways could exist in different cell types for down-regulating GPI-PLD expression during an inflammatory response and the TNF-alpha autocrine signaling mechanism alone is not sufficient to recapitulate the LPS-induced reduction of GPI-PLD in macrophages. Sublines of RAW 264.7 cells with reduced GPI-PLD expression exhibited increased cell sensitivity to LPS stimulation and membrane-anchored CD14 expression on the cell surface. Our data suggest that down-regulation of GPI-PLD could play an important role in the control of proinflammatory responses.

Inhibitory effect of berberine on the mediastinal lymph node metastasis produced by orthotopic implantation of Lewis lung carcinoma

We examined the effect of berberine, a major component with anti-fungal properties contained in Coptidis Rhizoma and Phellodendri Cortex, on the lymph node metastasis of murine lung cancer. Oral administration of berberine for 14 days significantly inhibited the spontaneous mediastinal lymph node metastasis produced by orthotopic implantation of Lewis lung carcinoma (LLC) into the lung parenchyma in a dose-dependent manner, but did not affect the tumor growth at the implantation site of the lung. Combined treatment with berberine and an anti-cancer drug, CPT-11, resulted in a marked inhibition of tumor growth at the implantation site and of lymphatic metastasis, as compared with either treatment alone. Anti-activator protein-1 (anti-AP-1) transcriptional activity of non-cytotoxic concentrations of berberine caused the inhibition of the invasiveness of LLC cells through the repression of expression of urokinase-type plasminogen activator (u-PA).

Recombinant toxins that bind to the urokinase receptor are cytotoxic without requiring binding to the alpha(2)-macroglobulin receptor

The alpha(2-)macroglobulin receptor (alpha(2)MR) has been reported to mediate the internalization of the urokinase plasminogen activator receptor (uPAR) via ligand binding to both receptors. To target malignant uPAR-expressing cells and to determine whether uPAR can internalize without ligand binding to alpha(2)MR, we engineered two recombinant toxins, ATF-PE38 and ATF-PE38KDEL. Each consists of the amino-terminal fragment (ATF) of human urokinase and a truncated form of Pseudomonas exotoxin (PE) devoid of domain Ia, which binds alpha(2)MR. ATF-PE38 and ATF-PE38KDEL were cytotoxic toward malignant uPAR-bearing cells, with IC(50) values as low as 0.02 ng/ml (0.3 pM). Cytotoxicity could be blocked using either recombinant urokinase or free ATF, indicating that the cytotoxicity of the recombinant toxins was specific. Radiolabeled ATF-PE38 had high affinity for uPAR (K(d) = 0.4-8 nM) on a variety of different malignant cell types and internalized at a rate similar to that of ATF. The cytotoxicity was not diminished by receptor-associated protein, which binds and shields the alpha(2)MR from other proteins, or by incubation with phorbol myristate acetate, which is known to decrease the number of alpha(2)MRs in U937 cells or by antibodies to alpha(2)MR. Therefore, these recombinant toxins appear to internalize via uPAR without association with the alpha(2)MR.

Identification of genes differentially over-expressed in lung squamous cell carcinoma using combination of cDNA subtraction and microarray analysis

In order to develop effective vaccine products against human cancer, we are interested in identifying genes over-expressed in tumor cells. Through a combination of cDNA library subtraction and microarray technology, we identified seventeen genes preferentially expressed in lung squamous cell carcinoma, including four novel genes. To date, expression profiles of these genes were confirmed by Northern and/or real-time analysis, and several genes were also found to be expressed in head and neck squamous tumors. Thus, these combined methods represent a high throughput approach for identifying tumor specific genes. Furthermore, the report of characterization on these genes will allow them to be exploited for their diagnostic, prognostic, and therapeutic potentials including immunotherapy and antibody based anticancer therapy.

The urokinase-type plasminogen activator system in resected non-small-cell lung cancer. Rotterdam Oncology Thoracic Study Group

BACKGROUND

Urokinase-type plasminogen activator (uPA), its receptor (uPAR) and plasminogen activator inhibitors (PAI-1 and PAI-2), all play important roles in tumour invasion and metastasis. The tumour levels of the components of the urokinase-type plasminogen activator system (uPA-system) may help to identify individuals with a poor prognosis in postoperative non-small-cell lung cancer (NSCLC) patients.

PATIENTS AND METHODS

The levels of uPA, uPAR PAI-1 and PAI-2 were measured by enzyme-linked immunosorbent assay (ELISA) in triton-extracts, prepared from 88 NSCLC tissues (stage I-IIIa) and 74 normal lung tissues from the same patients.

RESULTS

The expression levels of uPA, uPAR, PAI-1 and PAI-2 were significantly higher in tumour tissues as compared to their normal equivalents (all, P < 0.0001). Significant relations were found between gender and uPA (P = 0.04) or uPAR (P < 0.001), and between PAI-2 and pathological stage (P = 0.03). For none of the studied factors of the uPA-system a significant relation with survival was found, neither in all patients, nor in the subgroups of patients with squamous-cell lung carcinoma or adenocarcinoma.

CONCLUSIONS

The expression levels of the components of the uPA-system were higher in NSCLC tissue as compared to normal lung tissue, but there were no significant relationships between their levels and survival.

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.

TAC-101 (4-[3,5-bis(trimethylsilyl)benzamido]benzoic acid) inhibits spontaneous mediastinal lymph node metastasis produced by orthotopic implantation of Lewis lung carcinoma

The anti-tumor and anti-metastatic effects of 4-[3,5-bis(trimethylsilyl)benzamido]benzoic acid (TAC-101) were investigated using our established lung cancer model. Orthotopic implantation of Lewis lung carcinoma (LLC) cells into the lung parenchyma produced a solitary tumor nodule in the lung followed by mediastinal lymph node metastasis. Daily oral administration of TAC-101 at doses ranging from 4 to 16 mg/kg resulted in a significant inhibition of lymphatic metastasis (inhibition rate=57 to 76%), while only the dose of 16 mg/kg significantly inhibited tumor growth at the implanted sites (inhibition rate=46%). Combined treatment with cis-diamminedichloroplatinum (CDDP) and TAC-101 (8 mg/kg, p.o., daily) enhanced the anti-tumor effect of CDDP (7 mg/kg, i.v., bolus) against both the growth of implanted tumor and lymphatic metastasis. In addition, this combined treatment significantly prolonged the survival time of LLC tumor-bearing mice as compared to treatment with each agent alone. The anti-activating protein-1 (AP-1) activity of TAC-101 caused inhibition of LLC cell invasion through the repression of expression of urokinase-type plasminogen activator and its receptor. The anti-invasive activity of TAC-101 may be involved in its in vivo anti-metastatic activity. These findings suggest that TAC-101 is a novel anti-cancer agent that may improve the therapeutic modalities for lung cancer patients with metastatic disease.