Plasminogen- and colony-stimulating factor-1-associated markers in bladder carcinoma: diagnostic value of urokinase plasminogen activator receptor and plasminogen activator inhibitor type-2 using immunocytochemical analysis

SERPINB2, an Early Responsive Gene to Epigallocatechin Gallate, Inhibits Migration and Promotes Apoptosis in Esophageal Cancer Cells

Esophageal cancer is a lethal disease that frequently occurs in developing countries, the incidence of which could be declined by drinking EGCG-enriched drinks or food. SERPINB2, whose complex functions and regulations are not yet fully understood, are induced by multiple inflammatory molecules and anti-tumor agents. Here, we identify 2444 EGCG-regulated genes in esophageal cancer cells, including SERPINB2. EGCG treatment recruits NF-κB at the promoter and enhancers of SERPINB2 and activates gene transcription, which is repressed by NF-κB knockdown or inhibition. Loss of SERPINB2 leads to a faster migration rate and less expression of Caspase-3 in cancer cells. Our study demonstrates that SERPINB2 is a new tumor-suppressor gene involved in cell movement and apoptosis and could be a therapeutic target for esophageal cancer.

Effects of smoking on the tissue regeneration-associated functions of human endometrial stem cells via a novel target gene SERPINB2

BACKGROUND

Smokers directly inhale mainstream cigarette smoke, which contains numerous known and potential toxic substances, and thus, smoking is expected to have broad harmful effects that cause tissue injury and dysfunction. Interestingly, many studies have suggested that the recent decline in female fertility and increased rate of spontaneous abortion could be associated with increased smoking rates. Indeed, women that smoked for 10 years or more were reported to have a ~ 20% higher infertility rate than women that had never smoked. However, the reasons for the underlying harmful aspects of smoking on female fertility remain a matter of debate. Importantly, a previous study revealed that resident endometrial stem cell deficiency significantly limits the cyclic regeneration potential of endometrium, which, in turn, decreases successful pregnancy outcomes. In this context, we postulated that exposure to mainstream cigarette smoke extracts might decrease female fertility by inhibiting the functions of resident endometrial stem cells.

METHODS

We investigated whether cigarette mainstream smoke exposure directly inhibits various tissue regeneration-associated functions of endometrial stem cells, such as self-renewal, migration, pluripotency, and differentiation capacity in vitro. Next, we determined whether SERPINB2 mediates cigarette smoke-induced suppressive effects on various tissue regeneration-associated functions by depleting SERPINB2 expression with specific shRNA targeting SERPINB2. Mice were injected intraperitoneally with low (0.5 mg/kg) or high (1 mg/kg) doses of cigarette smoke extract (10 times for two weeks), and endometrial stem cells were then isolated from mice uterine tissues.

RESULTS

We found that exposure to cigarette smoke extracts remarkably suppressed various tissue regeneration-associated functions of endometrial stem cells, such as self-renewal, migration, multilineage differentiation ability, and pluripotency in vitro and in vivo by activating the SERPINB2 gene. Indeed, cigarette smoke-induced inhibitory effects on various endometrial stem cell functions were significantly abolished by SERPINB2 knockdown.

CONCLUSIONS

These findings provide valuable information on the harmful effects of cigarette smoking on resident endometrial stem cells and hopefully will facilitate the developments of promising therapeutic strategies for subfertile or infertile women that smoke cigarettes.

Construction and Validation of a 15-Top-prognostic-gene-based Signature to Indicate the Dichotomized Clinical Outcome and Response to Targeted Therapy for Bladder Cancer Patients

The clinical outcome of heterogeneous bladder cancer (BCa) is impacted by varying molecular characteristics and clinical features, and new molecular classification is necessary to recognize patients with dichotomized prognosis. We enrolled a total of 568 BCa patients from the TCGA-BLCA and GSE13507 cohorts. A total of 107 candidate genes, which were mostly involved in the extracellular matrix-associated pathway, were first selected through the consensus value of the area under the receiver operating characteristic curve (AUC). Furthermore, absolute shrinkage and selection operation regression analysis was implemented to reveal the 15 genes and establish the prognostic signature. The newly defined prognostic signature could precisely separate BCa patients into subgroups with favorable and poor prognosis in the training TCGA-BLCA cohort (p < 0.001, HR = 2.41, and 95% CI: 1.76–3.29), as well as the testing GSE13507 cohort (p < 0.001, HR = 7.32, and 95% CI: 1.76–3.29) and external validation E-MTAB-4321 cohort (p < 0.001, HR = 10.56, 95% CI: 3.208–34.731). Multivariate Cox analysis involving the signature and clinical features indicated that the signature is an independent factor for the prediction of BCa prognosis. We also explored potential targeted therapy for BCa patients with high- or low-risk scores and found that patients with high risk were more suitable for chemotherapy with gemcitabine, doxorubicin, cisplatin, paclitaxel, and vinblastine (all p < 0.05), but anti-PD-L1 therapy was useless. We knocked down HEYL with siRNAs in T24 and 5,637 cells, and observed the decreased protein level of HEYL, and inhibited cell viability and cell invasion. In summary, we proposed and validated a 15-top-prognostic gene-based signature to indicate the dichotomized prognosis and response to targeted therapy.

The impact of fine particulate matter (PM) on various beneficial functions of human endometrial stem cells through its key regulator SERPINB2

Fine particulate matter (PM) has a small diameter but a large surface area; thus, it may have broad toxic effects that subsequently damage many tissues of the human body. Interestingly, many studies have suggested that the recent decline in female fertility could be associated with increased PM exposure. However, the precise mechanisms underlying the negative effects of PM exposure on female fertility are still a matter of debate. A previous study demonstrated that resident stem cell deficiency limits the cyclic regenerative capacity of the endometrium and subsequently increases the pregnancy failure rate. Therefore, we hypothesized that PM exposure induces endometrial tissue damage and subsequently reduces the pregnancy rate by inhibiting various beneficial functions of local endometrial stem cells. Consistent with our hypothesis, we showed for the first time that PM exposure significantly inhibits various beneficial functions of endometrial stem cells, such as their self-renewal, transdifferentiation, and migratory capacities, in vitro and in vivo through the PM target gene SERPINB2, which has recently been shown to be involved in multiple stem cell functions. In addition, the PM-induced inhibitory effects on the beneficial functions of endometrial stem cells were significantly diminished by SERPINB2 depletion. Our findings may facilitate the development of promising therapeutic strategies for improving reproductive outcomes in infertile women.

Airborne pollutants may reduce female fertility through their debilitating effects on the stem cells that maintain the endometrium, the interior lining of the uterus. Recent evidence suggests that toxic byproducts from fossil fuels known as ‘particulate matter’ represent a danger to women’s reproductive health. South Korean researchers led by Ji-Won Jung, Korea Centers for Disease Control and Prevention, and In-Sun Hong, Gachon University, Incheon, have investigated this risk by exposing cultured human endometrial stem cells to diesel-derived particulate matter. These stem cells normally maintain the endometrium, allowing embryonic implantation to take place, but exposure to particulate matter greatly impaired the cells’ regenerative function. Mice exposed to particulate matter exhibited similar impairments of endometrial maintenance. The researchers identified a molecular pathway associated with this response that could guide development of fertility-restoring treatments.

Tumor-Associated Macrophages in Bladder Cancer: Biological Role, Impact on Therapeutic Response and Perspectives for Immunotherapy

Tumor-associated macrophages (TAMs) are one of the most abundant infiltrating immune cells of solid tumors. Despite their possible dual role, i.e., pro- or anti-tumoral, there is considerable evidence showing that the accumulation of TAMs promotes tumor progression rather than slowing it. Several strategies are being developed and clinically tested to target these cells. Bladder cancer (BCa) is one of the most common cancers, and despite heavy treatments, including immune checkpoint inhibitors (ICIs), the overall patient survival for advanced BCa is still poor. TAMs are present in bladder tumors and play a significant role in BCa development. However, few investigations have analyzed the effect of targeting TAMs in BCa. In this review, we focus on the importance of TAMs in a cancerous bladder, their association with patient outcome and treatment efficiency as well as on how current BCa treatments impact these cells. We also report different strategies used in other cancer types to develop new immunotherapeutic strategies with the aim of improving BCa management through TAMs targeting.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Development of a novel dual reproductive organ on a chip: recapitulating bidirectional endocrine crosstalk between the uterine endometrium and the ovary

Conventional 2D or even 3Din vitroculture models for human reproductive organs cannot properly recapitulate the bidirectional endocrine crosstalk between the uterine endometrium and the ovary. This crosstalk is essential for maintaining the various physiological features and functions of each tissue. Moreover, mostin vitromodels for the female reproductive tract also fail to mimic its multicellular structure. We therefore developed a novel 'dual reproductive organ on a chip' that reflects the bidirectional endocrine cross-talk and the complex multicellular structures by integrating various cellular components of both the human uterine endometrium and the ovary with several biodegradable natural polymers. Indeed, the bidirectional endocrine crosstalk between these two tissues is achieved through media sharing between channels, and it can markedly improve the viability of loaded cells within each chamber of the chip platform. In addition, we also identified a reliable reproductive toxicity marker, SERPINB2, which is significantly increased in response to various toxic exposures in both endometrial and ovarian follicular cells. Based on these findings, we next established a SERPINB2 luciferase reporter system that was specifically designed for detecting and quantifying the toxicity of certain substances. By introducing this SERPINB2 luciferase reporter system into the loaded cells within the chip platform, we ultimately developed an effective 'dual reproductive organ-on-chip' that was successfully used to predict the reproductive toxicity of various hazardous materials.

SERPINB2 Is a Novel Indicator of Cancer Stem Cell Tumorigenicity in Multiple Cancer Types

Drug resistance is one of the major characteristics of cancer stem cells (CSCs) and a mechanism of tumor recurrence. Therefore, selectively targeting CSCs may be an effective therapeutic strategy to overcome cancer recurrence. In the present study, we found that exposure to tumorigenic compounds significantly increased the growth potential and stem-cell-like properties of various CSCs. Early-response genes involved in tumorigenesis can be used as specific markers to predict potential tumorigenicity. Importantly, for the first time we identified, a labile tumorigenic response gene—SERPINB2—and showed that tumorigenic compound exposure more profoundly affected its expression in CSCs than in non-stem cancer cells, although both cells exhibit basal expression of SERPINB2 in multiple cancer types. Our data also revealed a strong relationship between the significantly enhanced expression of SERPINB2 and metastatic progression in multiple cancer types. To the best of our knowledge, this is the first study to focus on the functions of SERPINB2 in the tumorigenicity of various CSCs and these findings will facilitate the development of promising tumorigenicity test platforms.

SerpinB2 is involved in cellular response upon UV irradiation

Ultraviolet light induced pyrimidine dimer is a helix distortion DNA damage type, which recruits repair complexes. However, proteins of these complexes that take part in both DNA damage recognition and repair have been well-described, the regulation of the downstream steps of nucleotide excision repair (NER) have not been clearly clarified yet. In a high-throughput screen, we identified SerpinB2 (SPB2) as one of the most dramatically upregulated gene in keratinocytes following UV irradiation. We found that both the mRNA and the protein levels of SPB2 were increased upon UV irradiation in various cell lines. Additionally, UV damage induced translocation of SPB2 from the cytoplasm to the nucleus as well as the damage induced foci formation of it. Here we show that SPB2 co-localizes with XPB involved in the NER pathway at UV-induced repair foci. Finally, we demonstrated that UV irradiation promoted the association of SPB2 with ubiquitylated proteins. In basal cell carcinoma tumour cells, we identified changes in the subcellular localization of SPB2. Based on our results, we conclude that SPB2 protein has a novel role in UV-induced NER pathway, since it regulates the removal of the repair complex from the damaged site leading to cancerous malformation.

SERPINB2 is a novel indicator of stem cell toxicity

The toxicological evaluation of potential drug candidates is very important in the preclinical phase of drug development. Toxic materials may cause serious decline in stem cell function and loss of stemness. Indeed, we found that toxic exposure more profoundly suppressed the growth of stem cells than terminally differentiated fibroblasts. Importantly, toxic exposure suppressed stem cell migration and multi-lineage differentiation potential in vitro and in vivo. Moreover, early-response genes involved in stem cell properties such as self-renewal and differentiation capabilities can be used as specific markers to predict toxicity. In the present study, we also identified a labile toxic response gene, SERPINB2, which is significantly increased in response to various toxic agents in human stem cells in vitro and in vivo. Consistently, self-renewal, migration, and multi-lineage differentiation potential were markedly decreased following SERPINB2 overexpression. To the best of our knowledge, this is the first study to focus on the functions of SERPINB2 on the regenerative potential of stem cells in response to various existing chemicals, and the findings will facilitate the development of promising toxicity test platforms for newly developed chemicals.

microRNA-200c/141 upregulates SerpinB2 to promote breast cancer cell metastasis and reduce patient survival

The microRNA-200 (miR-200) family is associated with tumor metastasis and poor patient prognosis. We found that miR-200c/141 cluster overexpression upregulated SerpinB2 in the MDA-MB-231 triple-negative (TN) breast cancer cell line. We observed transcription factor (c-Jun, c-Fos, and FosB) upregulation, nuclear localization of c-Jun, and increased SerpinB2 promoter-directed chloramphenicol acetyltransferase activity in miR-200c/141 cluster-overexpressing cells relative to controls. Additionally, miR-124a and miR-26b, which directly target SepinB2, were downregulated compared to controls. In mouse xenograft models, miR-200c/141 cluster overexpression promoted lymph node and lung metastasis, and siRNA-mediated SerpinB2 knockdown decreased lung metastasis, suggesting that SerpinB2 mediates miR-200c/141-induced lung metastasis. We also explored the clinical significance of SerpinB2 protein status through analysis of primary breast tumor samples and The Cancer Genome Atlas (TCGA) data. High SerpinB2 levels were associated with reduced survival and increased lymph node metastasis in breast cancer patients. SerpinB2 was overexpressed in the TN breast cancer subtype as compared to the luminal subtype. The present study demonstrates that SerpinB2 promotes miR-200c/141 cluster overexpression-induced breast cancer cell metastasis, and SerpinB2 overexpression correlates with increased metastatic potential and unfavorable outcomes in breast cancer patients. SerpinB2 may be a useful biomarker for assessing metastasis risk in breast cancer patients.

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

Effect of urokinase-type plasminogen activator system in gastric cancer with peritoneal metastasis

Peritoneal metastasis is a primary cause of mortality in patients with gastric cancer. Urokinase-type plasminogen activator (uPA) has been demonstrated to be associated with tumor cell metastasis through the degradation of the extracellular matrix. The present study aimed to investigate the mechanisms of the uPA system in gastric cancer with peritoneal metastasis. Expression of uPA, uPA receptor (uPAR) and plasminogen activator inhibitor-1 (PAI-1) in four gastric cell lines (AGS, SGC7901, MKN45 and MKN28) was measured by semiquantitative reverse transcription polymerase chain reaction, enzyme-linked immunosorbent assay and western blotting. uPA activity was detected using a uPA activity kit. Peritoneal implantation models of rats were established by injecting four gastric cancer cell lines for the selection of the cancer cells with a high planting potential. Biological behaviors, including adhesion, migration and invasion, were determined using a methyl thiazolyl tetrazolium assay. Expression of the uPA system was observed to be highest in the SGC7901 cells among the four gastric cell lines. uPA activity was observed to be highest in the MKN45 cells and lowest in the AGS cells. Furthermore, peritoneal implantation analysis demonstrated that no peritoneal tumors were identified in the AGS cells, whilst the tumor masses observed in the SGC7901 and MKN45 cells were of different sizes. The survival times of the rats injected with the MKN28 and SGC7901 cells were longer than those of the rats injected with the MKN45 cells. Antibodies for uPA, uPAR and PAI-1 in the uPA system had the ability to inhibit the adhesion, migration and invasion of peritoneal metastasis in the gastric cancer cells. The results of the present study demonstrated that the uPA system was positively associated with peritoneal metastasis in gastric cancer.

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

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

Low expression of PAI-2 as a novel marker of portal vein tumor thrombosis and poor prognosis in hepatocellular carcinoma

BACKGROUND

Plasminogen activator inhibitor (PAI)-2 was previously shown to be less frequently expressed in hepatocellular carcinoma (HCC). The present study was designed to investigate the clinical, pathological, and prognostic significance of PAI-2 expression in HCC.

METHODS

Expression of PAI-2 was detected immunohistochemically for specimens from 78 patients with HCC after hepatic resection and correlated with clinicopathological features and patient survival. Risk factors of portal vein tumor thrombosis (PVTT) were also analyzed.

RESULTS

Positive PAI-2 staining was observed in tumor and non-tumor tissues from 21 (26.9%) and 56 (71.8%) patients, respectively. Plasminogen activator inhibitor-2 negativity in tumor tissues was significantly associated with PVTT, with a high sensitivity not only in univariate analysis but also in multivariate analysis. In addition, positive PAI-2 staining was related to smaller tumor size and prolonged patient survival. The Cox regression model identified intratumoral PAI-2 staining as an independent prognosticator in patients with HCC after resection.

CONCLUSIONS

Our data demonstrated that low expression of PAI-2 serves as a novel marker of PVTT and poor prognosis in HCC.

Expression of plasminogen activator inhibitor-2 is negatively associated with invasive potential in hepatocellular carcinoma cells

OBJECTIVE

To investigate the association between plasminogen activator inhibitor (PAI)-2 expression and invasive potential in hepatocellular carcinoma (HCC) cells.

METHODS

The HCC cell lines with high, low, and non-metastatic potentials, namely MHCC97-H, MHCC97-L, and SMMC-7721 respectively, were cultured in vitro. Matrigel invasion assay and Western blot of PAI-2 protein expression were conducted.

RESULTS

The number of invaded cells in MHCC97-L was significantly higher than that in SMMC-7721 (P=0.005), whereas that in MHCC97-H was higher than in MHCC97-L (P=0.017) and SMMC-7721 (P=0.001). Contrarily, PAI-2 protein expression was gradually reducing from SMMC-7721, MHCC97-L, to MHCC97-H (MHCC97-H vs. MHCC97-L, P<0.001; MHCC97-H vs. SMMC-7721, P=0.001; MHCC97-L vs. SMMC-7721, P=0.001). The Pearson's correlation analysis revealed a significant negative association between invaded cell number and PAI-2 expression (r=-0.892, P=0.001).

CONCLUSION

PAI-2 expression may be negatively associated with the invasive potential of HCC.

Retargeted adenoviral cancer gene therapy for tumour cells overexpressing epidermal growth factor receptor or urokinase-type plasminogen activator receptor

We have assessed the ability of bispecific fusion proteins to improve adenovirus-mediated transfer of therapeutic and marker transgenes. We constructed an expression vector that can be easily modified to synthesize a variety of fusion proteins for retargeting adenoviral gene therapy vectors to cell surface markers, which are differentially expressed between normal and cancer cells. Adenoviral transduction can be improved in a number of tumour cell lines which overexpress EGFR (epidermal growth factor receptor) or uPAR (urokinase-type plasminogen activator receptor), but which have only low levels of endogenous hCAR (human coxsackie B and adenovirus receptor) expression. Up to 40-fold improvement in beta-galactosidase transgene expression was seen using an EGFR retargeting protein, and up to 16-fold using a second fusion protein targeting uPAR. In vitro, our uPAR retargeting fusion protein improved the sensitivity to adenoviral herpes simplex virus thymidine kinase/ganciclovir by an order of magnitude, whereas in vivo, our EGFR retargeting protein is able to significantly delay tumour growth in rodent animal models in a dose-dependent manner. The 'cassette' design of our fusion protein constructs offers a flexible method for the straightforward synthesis of multiple adenoviral retargeting proteins, directed against a variety of tumour-associated antigens, for use in clinical trials.

Tumor-induced tolerance and immune suppression by myeloid derived suppressor cells

Emerging evidence indicates that the Achilles' heel of cancer immunotherapies is often the complex interplay of tumor-derived factors and deviant host properties, which involve a wide range of immune elements in the lymphoid and myeloid compartments. Regulatory lymphocytes, tumor-conditioned myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages, and dysfunctional and immature dendritic cells take part in a complex immunoregulatory network. Despite the fact that some mechanisms governing tumor-induced immune tolerance and suppression are starting to be better understood and their complexity dissected, little is known about the diachronic picture of immune tolerance. Based on observations of MDSCs, we present a time-structured and topologically consistent idea of tumor-dependent tolerance progression in tumor-bearing hosts.

Revisiting the biological roles of PAI2 (SERPINB2) in cancer

Tumour expression of the urokinase plasminogen activator correlates with invasive capacity. Consequently, inhibition of this serine protease by physiological inhibitors should decrease invasion and metastasis. However, of the two main urokinase inhibitors, high tumour levels of the type 1 inhibitor actually promote tumour progression, whereas high levels of the type 2 inhibitor decrease tumour growth and metastasis. We propose that the basis of this apparently paradoxical action of two similar serine protease inhibitors lies in key structural differences controlling interactions with components of the extracellular matrix and endocytosis-signalling co-receptors.

DBC1 re-expression alters the expression of multiple components of the plasminogen pathway

Deleted in bladder cancer 1 (DBC1) is a candidate gene for the bladder tumour suppressor locus at 9q33.1. The function of the gene is currently unknown but a cross-species sequence comparison suggests an important role, as it is highly evolutionarily conserved. Here, we transfected a nonexpressing human bladder cancer cell line with a set of human DBC1 cDNA constructs. The effect on global expression patterns was assessed using cDNA microarrays. The cell clone with the lowest level of DBC1 expression showed induced expression of 26 genes including plasminogen activator inhibitor 2 (SERPINB5; 4.6-fold), heparin-binding EGF-like growth factor precursor (DTR; 4.2-fold), small proline-rich protein 2B (SPRR2B; 3.6-fold), metallothionein 1 isoforms (MT1B/MT1A/MT-1F; from 2.9- to 3.2-fold), tissue-type plasminogen activator precursor (PLAT; 2.8-fold) and urokinase-type plasminogen activator precursor (PLAU; 2.7-fold). In clustering analysis, both PLAT and PLAU clustered with the functionally related urokinase plasminogen activator surface receptor (PLAUR; 1.9-fold). Furthermore, 14 human bladder tumours were analysed by real-time quantitative PCR using gene-specific primers for selected (n=20) genes. The expression levels of SERPINB5, PLAU, PLAUR and MT1 correlated with the DBC1 levels, suggesting previously unknown involvement of DBC1 in the urokinase-plasminogen pathway.

High expression of urokinase plasminogen activator receptor (UPA-R) in acute myeloid leukemia (AML) is associated with worse prognosis

Urokinase-type plasminogen activator receptor (UPA-R; CD87) is a membrane protein responsible for plasmin expression on cells facilitating cellular extravasations and tissue invasions. We studied the expression of the UPA-R on bone marrow (BM) cells of 93 patients with acute myeloid leukemia at first diagnosis and 8 healthy probands as controls by FACS analysis using phycoerythrin (PE)-conjugated antibodies. A case was defined as UPA-R-positive (UPA-R+) if >20% of the gated cells expressed UPA-R. Whereas none of the 8 healthy BM samples was positive for the UPA-R, 32 (34%) of the 93 AML samples were UPA-R+. Expression of UPA-R was heterogeneous in different FAB types, however, with the highest expression rates in monocytic subtypes (FAB M4/M5): 18%/19%/30% of UPA-R+ cases were found in M1/M2 or M3, and 58%/80% of cases with M4 or M5 were UPA-R+. Proportions of UPA-R+ cells varied between 1% and 98% of the mononuclear cell fractions, with the highest proportions in M4/M5 subtypes (on average 27%/40% UPA-R+ cells) and the lowest expression in AML M2 (11% UPA-R+ cells). The density of expressed UPA-R, estimated as mean channel fluorescence activity, was highest in cases with AML M1 (mFI: 124) followed by M4 and M5 (mFI: 78/77) and lowest in AML M2 (mFI: 43). In sAML, higher proportions of UPA-R+ cases (8 of 18; 44%) compared to pAML (24 of 75; 32%) were found as well as higher proportions of UPA-R+ cells (27% vs. 19%). Separating our patients' cohort in cytogenetic risk groups, we could not detect significant differences in the UPA-R expression profiles. For evaluations of the clinical course of AML, only patients treated by the AML-CG protocol (n = 65) were included. In the group of patients who did not respond to AML-CG therapy, significantly higher proportions of UPA-R+ cells (31% vs. 14%, P = 0.0015, t-test) were found. By evaluating a cut-off value for the percentage of positive cells that allows the most significant separation and differentiation between cases with shorter or longer relapse-free survival times, we could show that patients with >26.5% UPA-R-positive cells were characterized by a significantly higher risk for relapse compared to cases with <26.5% positive cells (P = 0.05). In summary, our data show a high expression of the UPA-R in AML, especially in (myelo)monocytoid subtypes. Cases with higher proportions of UPA-R+ cells were characterized by a significant lower remission rate after AML-CG therapy and a higher risk for relapse. Although prospective trials are still lacking, UPA-R is a prognostically relevant factor independent from the karyotype. UPA-R positivity may identify subtypes of AML associated with a more aggressive clinical course. Thus due to lower remission probabilities in UPA-R+ cases, a more intensive induction therapy regimen could be considered.

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

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

The novel targets for anti-angiogenesis of genistein on human cancer cells

Genistein has been reported to be a natural chemopreventive in several types of human cancer. In our prior study, soy isoflavones were shown to induce cell cycle arrest and apoptosis of bladder cancer cells in the range of human urine excretion. This study was designed to identify the novel molecular basis underlying anti-angiogenic activities of soy isoflavones. An immortalized E6 and five human bladder cancer cell lines were studied by immunoassay, flow cytometry, functional activity, reverse transcription-polymerase chain reaction, immunoblotting, and transwell co-culture in vitro. The efficacy of soy isoflavones on angiogenesis inhibition in vivo was examined by nude mice xenograft and chick chorioallantoic membrane bioassay. Factors analyzed included angiogenic factors, matrix-degrading enzymes, and angiogenesis inhibitors. Genistein was the most potent inhibitor of angiogenesis in vitro and in vivo among the isoflavone compounds tested. It may also account for most of the reduced microvessel density of xenografts observed and the suppressed endothelial migration by soy isoflavones. Genistein exhibited a dose-dependent inhibition of expression/excretion of vascular endothelial growth factor165, platelet-derived growth factor, tissue factor, urokinase plasminogen activator, and matrix metalloprotease-2 and 9, respectively. On the other hand, there was an up-regulation of angiogenesis inhibitors-plasminogen activator inhibitor-1, endostatin, angiostatin, and thrombospondin-1. In addition, a differential inhibitory effect between immortalized uroepithelial cells and most cancer cell lines was also observed. Altogether, we discovered that tissue factor, endostatin, and angiostatin are novel molecular targets of genistein. The current investigation provides further evidence in support of soy-based foods as natural dietary inhibitors of tumor angiogenesis.