Plasminogen activator inhibitors in endometrial adenocarcinoma

MicroRNA signature and regulatory functions in the endometrium during normal and disease states

During the menstrual cycle, human endometrium undergoes extensive cyclic morphologic and biochemical modifications in preparation for embryo implantation. These processes are highly regulated by ovarian steroids and various locally expressed gene products and involve inflammatory reaction, apoptosis, cell proliferation, angiogenesis, differentiation (tissue formation), and tissue remodeling. MicroRNAs (miRNAs) have emerged as key regulators of gene expression, and their altered and/or aberrant expression has been associated with establishment and progression of various disorders, including tumorigenesis. This review highlights the endometrial expression of miRNAs and their potential regulatory functions under normal and pathologic conditions such as endometriosis, dysfunctional uterine bleeding, and endometrial cancer. Given the key regulatory function of miRNAs on gene expression stability, understanding the underlying mechanisms of how endometrial miRNAs are regulated and identifying their specific target genes and their functions might lead to the development of preventive and therapeutic strategies by regulating specific target genes associated with such reproductive disorders.

Expression of E-Cadherin and uPA and their Association with the Prognosis of Pancreatic Cancer

OBJECTIVE

E-cadherin (ECD) and urokinase plasminogen activator (uPA) have been noted as markers for tumor metastasis and prognosis in several tumors. We thus investigated the relationship between the expression of ECD and uPA and the clinicopathological characteristics in pancreatic cancer.

METHODS

The expression of ECD and uPA was evaluated in pancreatic cancer tissues from 53 patients.

RESULTS

Among 53 tumor tissues, those from 29 (54.7%) patients showed positive ECD expression and those from 22 (41.5%) patients showed positive expression of uPA. There were four subgroups of ECD/uPA expression: ECD-positive/uPA-negative, ECD-negative/uPA-negative, ECD-positive/uPA-positive and ECD-negative/uPA-positive. These patterns were found in 14 (26.4%), 11 (20.8%), nine (17%) and 19 (35.8%) patients, respectively. The tumor tissues with ECD-negative and uPA-positive expression were associated with larger tumor, distant metastasis and an increased clinical stage. There was a difference in the median survival time between the patients with ECD-positive/uPA-negative pancreatic tissues (median: 18.7 months) and the patients with ECD-negative/uPA-positive pancreatic tissues (median: 7.5 months, P < 0.05), and there was a statistically significant difference in survival curves between these two groups.

CONCLUSION

The combined analysis concerning uPA and E-cadherin expression may be a useful predictor of metastasis in pancreatic cancer.

Prognostic relevance of TGF-beta1 and PAI-1 in cervical cancer

Cervical carcinoma is a human papilloma virus (HPV)-related immunogenic type of malignancy, in which escape of the tumor from the hosts' immune response is thought to play an important role in carcinogenesis. The multifunctional cytokine transforming growth factor-beta(1) (TGF-beta(1)) is involved in immunosuppression, stroma and extracellular matrix formation and controlling (epithelial) cell growth. The plasminogen activating (PA) system plays a key role in the cascade of tumor-associated proteolysis leading to extracellular matrix degradation and stromal invasion. Changes in expression of components of this system, including plasminogen activator inhibitor-1 (PAI-1), have been associated with poor prognosis in a variety of solid tumors. The present study was undertaken to assess the role of both components on relapse, survival and other clinicopathologic parameters in cervical cancer. The expression of TGF-beta(1) mRNA in 108 paraffin-embedded cervical carcinomas was detected by mRNA in situ hybridization. Immunohistochemistry was used to investigate the expression of PAI-1 protein. The presence of cytoplasmatic TGF-beta(1) mRNA in tumor cells was not significantly correlated with the other clinicopathologic parameters investigated or with a worse (disease-free) survival. Expression of the PAI-1 protein in tumor cells was strongly correlated with worse overall and disease-free survival, in addition to well-known prognostic parameters such as lymph node metastasis, depth of tumor infiltration, tumor size and vasoinvasion. In the multivariate analysis, PAI-1 turned out to be a strong independent prognostic factor. In a subgroup of patients without lymph node metastases, PAI-1 was predictive for worse survival and relapse of disease, too. Our results show that the (enhanced) expression of PAI-1 by carcinoma cells is correlated with worse (overall and disease-free) survival of patients with cancer of the uterine cervix. The expression of TGF-beta(1) in itself is not associated with worse survival in these patients. Although simultaneous presence of the 2 factors was observed in all tumors, induction of PAI-1 by TGF-beta(1) could not be demonstrated in our group of cervical carcinomas.

Expression of active plasminogen activator inhibitor-1 reduces cell migration and invasion in breast and gynecological cancer cells

Urokinase-type (uPA) plasminogen activator is regulated by serine protease inhibitors (serpins), especially plasminogen activator inhibitor-1 (PAI-1). In many cancers, uPA and PAI-1 contribute to the invasive phenotype. We examined the in vitro migration and invasive capabilities of breast, ovarian, endometrial, and cervical cancer cell lines compared to their plasminogen activator system profiles. We then overexpressed active wild-type PAI-1 and an inactive "substrate" P14 form of PAI-1 (T333R) using stable transfection and adenoviral gene delivery. We also upregulated endogenous uPA and PAI-1 in these cells by treatment with transforming growth factor-beta. Some breast and ovarian cancer cell lines with natural expression of uPA, PAI-1, and urokinase receptor showed substantial migration and invasion compared to other cell lines that lack expression of these proteins. However, overexpression of active wild-type PAI-1, but not P14-PAI-1 (T333R), in these cell lines showed reduced migration and invasion. Since vitronectin binding by both forms of PAI-1 is equivalent, these results imply that PAI-1-vitronectin interactions are less critical in altering migration and invasion. Our results show that the in vitro migratory and invasive phenotype in these breast and ovarian cancer cell lines is reduced by active PAI-1 due to its ability to inhibit plasminogen activation.

Cancer of the endometrium: current aspects of diagnostics and treatment

Background

Endometrial cancer represents a tumor entity with a great variation in its incidence throughout the world (range 1 to 25). This suggests enormous possibilities of cancer prevention due to the fact that the incidence is very much endocrine-related, chiefly with obesity, and thus most frequent in the developed world. As far as treatment is concerned, it is generally accepted that surgery represents the first choice of treatment. However, several recommendations seem reasonable especially with lymphadenectomy, even though they are not based on evidence. All high-risk cases are generally recommended for radiotherapy.

Methods

A literature search of the Medline was carried out for all articles on endometrial carcinoma related to diagnosis and treatment. The articles were systematically reviewed and were categorized into incidence, etiology, precancerosis, early diagnosis, classification, staging, prevention, and treatment. The article is organized into several similar subheadings.

Conclusions

In spite of the overall good prognosis during the early stages of the disease, the survival is poor in advanced stages or recurrences. Diagnostic measures are very well able to detect asymptomatic recurrences. These only seem justified if patients' chances are likely to improve, otherwise such measures increases costs as well as decrease the patients' quality of life. To date neither current nor improved concepts of endocrine treatment or chemotherapy have been able to substantially increase patients' chances of survival. Therefore, newer concepts into the use of antibodies e.g. trastuzumab in HER2-overexpressing tumors and the newer endocrine compounds will need to be investigated. Furthermore, it would seem highly desirable if future studies were to identify valid criteria for an individualized management, thereby maximizing the benefits and minimizing the risks.

Urokinase plasminogen activator system: a multifunctional role in tumor progression and metastasis

The urokinase plasminogen activator (uPA) system is central to a spectrum of biologic processes including fibrinoloysis, inflammation, atherosclerotic plaque formation, matrix remodeling during wound healing, tumor invasion, angiogenesis, and metastasis. Binding of uPA with its receptor (uPAR) initiates a proteolytic cascade that results in the conversion of plasminogen to plasmin. Plasmin through its own proteolytic function degrades a range of extracellular basement membrane components and activates others such as the metalloproteinases. Independent of catalytic activity, uPAR also is involved in cell signaling, interactions with integrins, cell motility, adhesion and invasion, and angiogenesis. Over expression of uPA or uPAR is a feature of malignancy and is correlated with tumor progression and metastasis. In contrast, inhibition of expression of these components leads to a reduction in the invasive and metastatic capacity of many tumors. Strategies that target uPA or its receptor with the aim of disrupting the interaction between the two or the ligand independent actions of uPAR include antisense technology, monoclonal antibodies, cytotoxic antibiotics, and synthetic inhibitors of uPA. Targeted therapy is a goal of future cancer treatment and the uPA system is a likely candidate for manipulation.

Urokinase plasminogen activator and its inhibitor, PAI-1, in association with progression-free survival in early stage endometrial cancer

Components of the urokinase plasminogen activator (u-PA) system are involved in the metastatic process, and have accordingly been associated with clinical outcome in a variety of malignant tumours. We investigated the prognostic importance of u-PA and plasminogen activator inhibitor type 1 (PAI-1) in endometrial cancer, analysed with luminometric immunoassay (LIA) and enzyme-linked immunosorbent assay (ELISA), respectively. Two different cut-off levels were used: the median and the 80th percentile-the latter because of the low progression rate for patients with early stage (I-II) endometrial cancer. After a median follow-up time of 6.8 years, univariate analysis of patients with stage I-II disease (n=188) showed that high u-PA and high PAI-1 content was associated with a shorter progression-free survival (PFS), but at different cut-off levels, uPA at the median (P=0.003), and PAI-1 at the 80th percentile (P<0.001). Among the other factors, DNA ploidy status was most strongly correlated to PFS, followed by age (continuous), International Federation of Gynaecology and Obstetrics (FIGO) grade of differentiation, S-phase fraction and progesterone receptor (PgR) status. Bivariate analyses, including ploidy and one of the factors u-PA or PAI-1, showed that both add significant prognostic information. We conclude that u-PA and PAI-1 are promising prognostic factors in early stage endometrial cancer.

Theories of endometriosis

Endometriosis is characterised by the presence of abnormally located tissue resembling the endometrium with glands and stroma. Several hypotheses have attempted to explain the development of such tissue. The oldest theory, that of metaplasia, suggests that under diverse influences coelomic tissue could be transformed into endometrium. The most often cited theory, that of implantation, proposes that the physiological phenomenon of endometrial reflux in the fallopian tubes during menstruation may, in certain conditions, overcome local defense mechanisms, implant, and proliferate. The peritoneal fluid in unaffected women possesses the capacity to prevent endometriotic tissue from becoming established. The reasons for the occurrence of endometriosis and its consequences (pain, sterility, adhesions) are probably numerous and involve the endometrium, the immune system (macrophages, natural killer cells), the peritoneum, and fallopian tubes. The failure to clear the peritoneal cavity of fragments of endometrium could cause a state of local inflammation with hyperactivation of macrophages secreting a variety of different compounds. Some of these compounds may bring about metaplasia of the peritoneum or the development of Mullerian residues.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Is endometriosis an endometrial disease?

Endometriosis is characterised by the presence of abnormally located tissue resembling the endometrium with glands and stroma. Several hypotheses have attempted to explain the development of such tissue. The most often cited theory, that of implantation, proposes that the physiological phenomenon of endometrial reflux in the fallopian tubes during menstruation may, in certain conditions, overcome local defense mechanisms, implant, and proliferate. The implantation theory does not explain why endometriosis will develop only in approximately 10-15% of women, while the reflux of endometrial tissue via the fallopian tubes during menstruation is a quasi-universal phenomenon. The endometrium of women affected by endometriosis could be abnormal compared with endometrium of healthy women. The abnormal endometrium could be able to protect itself from harmful effects of immune cells by expressing specific antigens, by harbouring a different immune cell population and by synthetizing and secreting immunosuppressive factors. Several others characteristic features of endometrium have been described in women with endometriosis: (1) production of its own estrogens in too heavy amount; (2) aptitude for setting up on peritoneum; (3) tendencies to proliferate and to invade tissue; (4) aggressiveness for the peritoneum; (5) auto-protection from physiological apoptosis; (6) abnormal expression of heat shock proteins; and (7) excessive angiogenesis.

Urokinase gene expression indicates early invasive growth in squamous cell lesions of the uterine cervix

The plasminogen activating system plays a key role in the cascade of tumour-associated proteolysis leading to extracellular matrix degradation and stromal invasion. Changes in the expression of this system, consisting of urokinase- and tissue-type plasminogen activators (uPA and tPA, respectively), plasminogen activator inhibitors (PAI-1, PAI-2) and uPA receptor, have been associated with tumour aggressiveness in a variety of solid malignant tumours. This paper describes a study of squamous intraepithelial lesions (SILs, n=36), squamous cell carcinomas (SCCs, n=42), and normal mucosa (n=5) of the uterine cervix by in situ hybridization with (35)S-labelled RNA probes. uPA transcripts were absent from normal mucosa and non-invasive lesions, but present in atypical epithelial cells of all microinvasive carcinomas ( n=19) and in some of the more advanced invasive carcinomas (n=11). PAI-1 transcripts were found in stromal cells of most tissue samples with, however, significantly increased levels in invasive SCC compared with SIL, microinvasive SCC, and normal mucosa. uPA-positive invasive carcinomas often displayed additional PAI-1 expression by tumour cells. At variance with uPA, tPA transcripts were found in atypical epithelial cells of low- and high-grade SILs. In the majority of SCCs tested (27/29 cases), the HPV 16 E6/E7 oncogene and uPA transcription were correlated. uPA and PAI-1 expression indicates invasive growth when expressed by atypical epithelial cells of squamous cervical lesions. Moreover, the presence of uPA transcripts is indicative of early invasive growth. uPA and tPA seem to have different functions in the development of invasive properties in uterine cervical squamous epithelium.

Expression of dioxin-responsive genes in human endometrial cells in culture

To investigate expression of dioxin-responsive genes in human endometrial cells with exposure to 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD), human endometrial stromal cells immortalized with temperature-sensitive SV40 T antigen were used for the experiments. Cells were treated with 0.1% DMSO or 0.1, 1, 10, or 100 nM TCDD for 24 h. Induction of interleukin-1beta (IL-1beta) and plasminogen activator inhibitor-2 (PAI-2) mRNAs was analyzed by reverse-transcription polymerase chain reaction. Expression of IL-1beta or PAI-2 mRNA in response to TCDD was increased in a dose-dependent fashion. The maximum increases of PAI-2 and IL-1beta mRNAs were observed at 100 and 10 nM TCDD, respectively. While cycloheximide treatment did not show a significant difference of PAI-2 mRNA levels between control and TCDD-treated cells, mRNA stability assay using actinomycin D showed that PAI-2 mRNA in TCDD-treated cells was about twofold more stable than the control cells. While expression of CYP1A1 mRNA was not detected and levels of ARNT mRNA were not altered by TCDD exposure, the amount of AhR mRNA was decreased dose dependently. The present study represents an initial attempt to determine the responses of dioxin-responsive genes in human endometrial cells following TCDD exposure. The results demonstrated that IL-1beta and PAI-2 genes are induced dose dependently in human endometrial cells with exposure to TCDD and expression of PAI-2 mRNA is controlled at the posttranscriptional level.

Plasminogen activators and inhibitors in ovarian adenocarcinomas

The fibrinolytic process was examined in cultures from malignant epithelial ovarian tumors and compared to normal ovarian tissue. The fibrinolytic enzymes, urokinase plasminogen activator (uPA) antigen and activity, tissue plasminogen activator (tPA) antigen and activity, plasminogen activator inhibitor 1 (PAI-1) and plasminogen activator inhibitor 2 (PAI-2) antigen were measured in short-term primary cultures at weekly intervals over a 3-week period. The cultures comprised of 15 ovarian adenocarcinomas and 12 normal ovarian tissue samples. The concentration of uPA antigen (p < 0.01) and activity (p < 0.01) and (p < 0.05) levels were higher in malignant specimens on all 3 count days. Activity levels of tPA were elevated significantly in malignant specimens on days 7 and 21 (p < 0.05). No significant difference was found between PAI-1 levels. PAI-2 antigen levels were significantly higher in the tumor specimens on days 14 and 21 (P < 0.01). These data indicate that uPA may have a significant role in the biology of ovarian cancer and may be an important factor in early tumor spread. Further work is required on the effects of intervention in this biological process.

Blood and tissue fibrinolytic profiles in patients with colorectal carcinoma

In patients with colorectal cancer, profound alterations of the plasminogen activator system have been described at the tumor level, but conflicting results have been obtained for fibrinolytic parameters in plasma. Components of the fibrinolytic system, including tissue-type and urokinase-type plasminogen activators and their inhibitors type 1 and 2, were measured in tissue and/or plasma from 41 patients with colorectal cancer and in 40 controls. Procoagulant activity of freshly isolated mononuclear cells (basal activity) and the procoagulant activity and fibrinolytic proteins produced by the cells after incubation for 18 h without exogenous stimulation were also evaluated. Malignant tissue extracts had significantly higher levels of urokinase-type plasminogen activator and plasminogen activator inhibitor-1, but lower levels of tissue-type plasminogen activator than normal mucosa. Plasminogen activator inhibitor-1 alone was higher in advanced (Dukes' stages C + D) than limited (B) tumors. Plasminogen activator inhibitor-2 was not different in malignant tissue and normal mucosa. Plasma levels of plasminogen activator inhibitor-1 antigen were significantly increased in cancer patients compared with controls, but there were no differences in tissue-type and urokinase-type plasminogen activator, in plasminogen activator inhibitor-2, and D-dimer levels. Intra-patient analysis revealed no significant correlation between tumor and plasma levels of plasminogen activators or type 1 inhibitor. Tissue-type plasminogen activator, but not the urokinase type or inhibitor type 1, was higher in venous than in arterial blood collected at the tumor site during surgery. Basal procoagulant activity of mononuclear cells and the procoagulant activity and inhibitor type-2 produced by the cells after short-term culture were comparable in patients and controls. These findings indicate that, at least in our patients with colorectal cancer, the profound changes occurring at tumor level are barely detectable in the blood. Thus, the clinical relevance of plasma fibrinolytic parameters, especially urokinase-type plasminogen activator antigen, as tumor markers in colorectal cancer remains to be established.

The significance of urokinase- type plasminogen activator, its inhibitors, and its receptor in ascites of patients with epithelial ovarian cancer

BACKGROUND

Strong correlations have been reported between expression of urokinase-type plasminogen activator (uPA) and poor prognosis in several human carcinomas. The clinical significance of secreted levels of uPA, its receptor (uPAR), and its inhibitors (PAI-1 and PAI-2) in the ascites of patients with epithelial ovarian cancer patients was investigated.

METHODS

uPA, uPAR, PAI-1, and PAI-2 were measured in the primary ascites of 36 patients with epithelial ovarian cancer by enzyme-linked immunosorbent assay, and normalized to protein content. The relationship between levels of these factors in ascites and clinicopathologic variables, survival, and disease free interval (DFI) was studied. Because high levels of macrophage colony stimulating factor (CSF-1) in ascites is a known poor prognostic indicator for ovarian cancer, the effect of CSF-1 on secretion of PAI-2 by ovarian cancer cells was also examined in vitro.

RESULTS

High uPA levels per se did not correlate with either survival or DFI. However, the ratio of uPAR normalized for uPA content correlated inversely with FIGO stage and residual disease, with a significant association between high uPAR/uPA level and prolonged survival and DFI. High PAI-1 levels (> 0.120 ng/mg) proved to be a good prognostic factor, correlating with both prolonged DFI and residual disease < or = 5 cm among Stage 3 patients. Conversely, high levels of PAI-2 (> 0.061 ng/mg) indicated a poor prognosis in Stage 3 patients, as high PAI-2 levels were associated with shorter DFI and survival. CSF-1 stimulated the secretion of PAI-2 by 2.4-fold in Bix3 ovarian carcinoma cells. Multivariate analysis revealed that the two independent prognostic factors for DFI in Stage 3 patients were PAI-1 and PAI-2; Stage 3 patients with high secreted PAI-1 and low PAI-2 levels have a median DFI that was prolonged by 30 months relative to the rest of the group.

CONCLUSION

Secreted uPAR/uPA appears to measure tumor burden and predicts prolonged DFI and survival, but was not found to be an independent prognostic factor on multivariate analysis. High levels of PAI-1 in ascites were independently associated with prolonged DFI among Stage 3 patients. Therefore, secreted uPAR and PAI-1 may modulate uPA activity and lead to improved outcome. This contrasts with the finding that secreted PAI-2 is an independent factor indicating poor prognosis, which may relate in part to the actions of CSF-1. This study emphasizes the importance of uPA, its receptor, and its inhibitors in patients with epithelial ovarian cancer.

Localization of urokinase-type plasminogen activator, plasminogen activator inhibitor-1, 2 and plasminogen in colon cancer

We examined the localization of urokinase-type plasminogen activator (u-PA), plasminogen activator inhibitors (PAI-1 and PAI-2) and plasminogen (plg) in 26 cases of colon cancer by immunohistochemical staining. The u-PA antigen was detected in the cytoplasm of cancer cells (18/26) and stromal cells adjacent to cancer tissues (9/26). The localization of u-PA mRNA examined by in situ hybridization was consistent with that of u-PA antigen. The PAI-1 antigen was detected in fibroblasts and endothelial cells (22/26), while PAI-2 antigen was found in cancer cells (20/26). The plg antigen was seen in the extracellular matrix of the cancer stroma. The u-PA expression in cancer cells was significantly more frequently detected in cases with lymph node metastasis than in cases without metastasis. In either PAI-1- or PAI-2-expressing cases, lymph node metastasis seemed to be restrained. These findings indicate that cancer cells themselves produce u-PA, and suggest that u-PA converts plg into plasmin, which dissolves the extracellular matrix surrounding cancer cells, resulting in cancer invasion and metastasis. PAI-1 and PAI-2 may have inhibitory actions on cancer invasion and metastasis mediated by u-PA.

Hemostatic changes in patients with brain tumors

Abnormal hemostasis is a functional property of cancer. Hemostatic abnormalities are common in patients with systemic malignant disease and brain tumors. However, the incidence of thromboembolism is higher in patients with brain tumors than in those with systemic disease. This raises the question of whether or not hemostatic abnormalities found in the blood of the two groups of patients differs, suggesting different pathogeneses. The purpose of this report is to review abnormalities in blood and clinical manifestations of abnormal hemostasis found in brain tumors and cancer patients in an attempt to answer this question. Normal hemostasis, as currently understood, will be considered with an emphasis on features unique to the central nervous system.