Coexisting macrophage-associated fibrin formation and tumor cell urokinase in squamous cell and adenocarcinoma of the lung tissues

A Single-Center Experience of Mechanical Thrombectomy for Cancer-Associated Ischemic Stroke

Objectives

Cancer-associated ischemic stroke tends to extend over multiple vascular territories and develops under poor general conditions. Owing to the rarity of such cases and poor prognoses, no comprehensive studies on mechanical thrombectomy for cancer-associated ischemic stroke have been reported in Japan. The present study investigated the radiological and clinical characteristics of mechanical thrombectomy in patients with cancer-associated ischemic stroke at our institution.

Methods

We retrospectively reviewed 108 patients who underwent mechanical thrombectomy for large cerebral artery occlusion between January 1, 2021, and October 31, 2022, at our institution. The characteristics of mechanical thrombectomy in the cancer-associated ischemic stroke group were compared with those in the control group.

Results

Of the 108 patients (112 procedures), seven patients (eight procedures) with clinically diagnosed cancer-associated ischemic stroke underwent mechanical thrombectomy. Of the eight procedures, six were performed during hospitalization. In contrast, only 10 of 104 procedures were performed in the control group. The in-hospital onset rate was higher in the cancer-associated ischemic stroke group (75.0%) compared to that in the controls (9.6%); p <0.001. The puncture-to-reperfusion time was significantly longer in the cancer-associated ischemic stroke group in comparison to that in the controls with a median interquartile range of 69 minutes (60.0-82.0 minutes) and 59.5 minutes (44.5-69.3 minutes), respectively (p <0.01). However, the rates of successful recanalization defined as thrombolysis in cerebral infarction ≥2b were not significantly different between the cancer-associated ischemic stroke group and controls with values of 62.5% and 79.8%, respectively (p = 0.250). Of the eight cases in the cancer-associated ischemic stroke group, only one (12.5%) had a good outcome on a modified Rankin Scale score of 0 to 2 at discharge, in contrast to 23 of the 104 (23.1%) cases in the controls (p = 0.523). Histopathological examination of six retrieved thrombi in the cancer-associated stroke group using hematoxylin and eosin staining revealed that only one case showed an erythrocyte-dominant thrombus while five displayed a fibrinoplatelet-dominant component. Conversely, 65 of 92 retrieved thrombi in the control group were erythrocyte dominant. Cancer was pathologically diagnosed in four of seven patients, all of which were adenocarcinomas.

Conclusion

Cancer-associated ischemic stroke tends to occur during hospitalization. Coagulation disorders associated with cancer, especially adenocarcinoma, may be related to the formation of thrombi with fibrinoplatelet-dominant components, leading to ischemic stroke. The procedural time for mechanical thrombectomy in cancer-associated ischemic stroke tends to be longer.

F12 as a reliable diagnostic and prognostic biomarker associated with immune infiltration in papillary thyroid cancer

Objective: To explore the function of coagulation factor XII (F12) in papillary thyroid cancer (PTC).

Materials and Methods: We assessed F12 expression and its relationship with overall survival (OS) in various cancers using TIMER and TISIDB databases. Further, we evaluated the mRNA and protein expression levels of F12 in PTC via different bioinformatics tools. The receiver operating characteristic (ROC) curve was applied to determine the diagnostic value of F12 in PTC. Then, the Kaplan-Meier plotter and Cox regression analyses were performed to examine the prognostic significance of F12. The possible mechanism of F12 in PTC was investigated through enrichment analyses. Finally, the correlation between F12 expression and immune cell infiltration was analyzed using TCGA data.

Results: This study revealed the clinical significance of F12 in various cancers. Higher mRNA (P <0.001) and protein expressions of F12 were observed in PTC compared with normal tissues. Besides, F12 expression exhibited high diagnostic performance in PTC and its overexpression served as an independent predictor for the poor OS (P <0.05). Enrichment analyses results showed that F12 was mainly involved in metabolism-associated pathways. Additionally, F12 expression was significantly linked to immune cell infiltration levels, especially macrophage infiltration.

Conclusions: F12 might be a reliable diagnostic and prognostic biomarker for PTC. Moreover, F12 expression might affect the OS of PTC patients via regulating metabolic pathways.

Plasmin and Plasminogen System in the Tumor Microenvironment: Implications for Cancer Diagnosis, Prognosis, and Therapy

Simple Summary

In this review, we present a detailed discussion of how the plasminogen-activation system is utilized by tumor cells in their unrelenting attack on the tissues surrounding them. Plasmin is an enzyme which is responsible for digesting several proteins that hold the tissues surrounding solid tumors together. In this process tumor cells utilize the activity of plasmin to digest tissue barriers in order to leave the tumour site and spread to other parts of the body. We specifically focus on the role of plasminogen receptor—p11 which is an important regulatory protein that facilitates the conversion of plasminogen to plasmin and by this means promotes the attack by the tumour cells on their surrounding tissues.

Abstract

The tumor microenvironment (TME) is now being widely accepted as the key contributor to a range of processes involved in cancer progression from tumor growth to metastasis and chemoresistance. The extracellular matrix (ECM) and the proteases that mediate the remodeling of the ECM form an integral part of the TME. Plasmin is a broad-spectrum, highly potent, serine protease whose activation from its precursor plasminogen is tightly regulated by the activators (uPA, uPAR, and tPA), the inhibitors (PAI-1, PAI-2), and plasminogen receptors. Collectively, this system is called the plasminogen activation system. The expression of the components of the plasminogen activation system by malignant cells and the surrounding stromal cells modulates the TME resulting in sustained cancer progression signals. In this review, we provide a detailed discussion of the roles of plasminogen activation system in tumor growth, invasion, metastasis, and chemoresistance with specific emphasis on their role in the TME. We particularly review the recent highlights of the plasminogen receptor S100A10 (p11), which is a pivotal component of the plasminogen activation system.

Anti-Metastatic Effects of Antrodan with and without Cisplatin on Lewis Lung Carcinomas in a Mouse Xenograft Model

Antrodan, a unique protein-bound polysaccharide derived from the fungal mycelia of Antrodia cinnamomea, has been reported to exhibit antitumor and anti-metastatic effects on Lewis lung carcinoma (LLC) cells through direct action and immunomodulation in vitro. In this study, we investigated the combined treatment of antrodan with an anti-cancer drug-cisplatin-and its underlying molecular mechanisms of action in a mouse xenograft tumor model. C57BL/6 mice were implanted (s.c.) with LLCs for nine days, before administration with only antrodan (20 mg/kg and 40 mg/kg; p.o.) daily, only cisplatin (1 mg/kg; i.p.) twice per week, or a combination of both for an additional 28 days. As expected, antrodan on its own significantly inhibited metastasis of lung and liver tissues, while treatment with cisplatin only merely inhibited metastasis of the liver. Antrodan exhibited efficient adjuvant therapy in combination with cisplatin, by inhibiting the activities of the plasma urokinase plasminogen activator (uPA) and the liver matrix metalloproteinase 9 (MMP-9), as well as by inhibiting the phosphorylation of p38 and extracellular signal-regulated kinase 2 (ERK2) in lung and liver tissues. In addition, antrodan effectively ameliorated cisplatin-induced kidney dysfunction when treated combinatorially, as evidenced by a decrease in cisplatin-induced blood urea nitrogen (BUN) levels in plasma and in the level of p38 phosphorylation in the kidney. Mechanistically, the actions of antrodan on its own involved (i) reducing the activities of uPA and MMP-2 and -9 in plasma; (ii) reducing protein expression of MMP-2/9, and the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinases (ERKs), c-Jun N-terminal kinases (JNKs), and p38 in lung and liver tissues; and (iii) enhancing immune system functions resulting in the promotion of an anti-metastatic response through immunomodulation, by increasing interferon-γ (IFN-γ) levels and decreasing interleukin-6 (IL-6) levels in plasma. These results demonstrated that antrodan provides a novel, complementary therapeutic strategy against cancer metastasis, by attenuating the activities of MMP-2 and -9 through the modulation of STAT3/MAPK/ERK/JNK signaling pathways, and of the host's immune system.

Venous thromboembolism and lung cancer: a review

Venous thromboembolism (VTE) is a common complication of malignancies and epidemiological studies suggest that lung cancer belonged to the group of malignancies with the highest incidence rates of VTE. Risk factors for VTE in lung cancer patients are adenocarcinoma, NSCLC in comparison with SCLC, advanced disease, pneumonectomy, chemotherapy including antiangiogenic therapy. Other risk factors are pretreatment platelet counts and increased release of TF-positive microparticles. Elevated D-dimer levels do not necessarily indicate an increased risk of VTE but have been shown to be predictive for a worse clinical outcome in lung cancer patients. Mechanisms responsible for the increase in venous thrombosis in patients with lung cancer are not understood.

Currently no biomarker is recognized as a predictor for VTE in lung cancer patients.

Although several clinical trials have reported the efficacy of antithrombotic prophylaxis in patients with lung cancer who are receiving chemotherapy, further trials are needed to assess the clinical benefit since these patients are at an increased risk of developing a thromboembolism.

The incidence and predictors of thromboembolic events in patients with lung cancer

Patients with lung cancer experience elevated risk of venous thromboembolism. Cancer patients with thrombosis have a shorter life expectancy and the occurrence of VTE worsens the quality of life and may delay, interrupt, or completely halt the cancer therapy. In a large cohort of lung cancer patients we monitored the incidence of venous thromboembolism and we identified groups of patients with the highest risk of venous thromboembolism suitable for antithrombotic prophylaxis, which could favourably affect their morbidity and mortality.

Protein Z/protein Z-dependent protease inhibitor system in human non-small-cell lung cancer tissue

INTRODUCTION

NSCLC progression is often associated with VTE. Activation of factor X is an important step in blood coagulation activation in cancer patients. PZ)/ZPI contribute to direct factor Xa inhibition, and ZPI - attenuates factors IXa and XIa activity. The role of the PZ/ZPI in NSCLC is obscure. The aim of the study was to localize ZPI and PZ in NSCLC tissue in relation to factors X, IX and XI, as well as indicators of blood coagulation activation: prothrombin fragment F1+2 (F1+2) and fibrin.

MATERIAL & METHODS

Immunohistochemical studies were performed on surgical NSCLC specimens employing antibodies against ZPI, PZ, coagulation factors X, IX, XI, as well as fibrinogen, F1+2 and fibrin. A semiquantitative analysis (acc. to immunoreactive score-IRS) was conducted.

RESULTS

Medium expression of ZPI(IRS=6.5), together with weak expression of PZ(IRS=4), was observed in cancer cells. Strong or medium staining for factors IX, X, and XI(IRS=8-9) was revealed in cancer cells. Fibrinogen(IRS=10) and fibrin(IRS=8) were demonstrated in tumor stroma and cancer cells. F1+2(IRS=10) was localized in NSCLC cells. Endothelial cells (ECs) and tumor infiltrating macrophages (TAMs) were characterized by a positive staining for ZPI and PZ.

CONCLUSIONS

ZPI and PZ expression in NSCLC cells, ECs and TAMs may suggest a role for PZ/ZPI in the anticoagulant mechanisms at the tumor site. The presence of F1+2 and fibrin, along with a disproportional expression of ZPI and PZ, might point to impaired function of the coagulation inhibitory system in NSCLC tissue.

Tissue inhibitor of metalloproteinase 1 is an independent predictor of prognosis in patients with nonsmall cell lung carcinoma who undergo resection with curative intent

BACKGROUND

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) play a role in the processes of extracellular matrix degradation. Changes in their expression levels have been observed in various tumor types, including lung carcinoma. However, their clinical significance and their prognostic importance in the progression of nonsmall cell lung carcinoma (NSCLC) remain to be specified. In this study, mRNA expression levels of MMP-1, MMP-9, TIMP-1, and TIMP-2 were evaluated in patients with resected NSCLC, and their associations with disease progression and prognosis were determined.

METHODS

Between June 1996 and December 1999, 116 patients underwent resection for NSCLC. Expression levels of MMPs and TIMPs were evaluated using Northern blot analysis in these NSCLC tissue samples and in 39 matched samples of normal lung tissue.

RESULTS

MMP-1, MMP-9, and TIMP-1 expression levels were increased in tumor samples compared with matched, corresponding normal tissues. In contrast, TIMP-2 expression was decreased in tumor samples. MMP-1 tumor expression was correlated significantly with the evolution of lymph node status and tumor-lymph node-metastasis (TNM) stage. In contrast, MMP-9 tumor expression was correlated significantly with increased T stage. TIMP-1 overexpression was an independent predictor of worse survival in patients with NSCLC that was not associated with other prognosis factors, such as TNM stage.

CONCLUSIONS

The overexpression of TIMP-1 was an independent prognostic marker in patients with NSCLC, and evaluating TIMP-1 may be important for identifying patients who are at greater risk of disease recurrence.

Platelet-CD40 ligand interaction with melanoma cell and monocyte CD40 enhances cellular procoagulant activity

Platelet-tumor cell interactions are believed to be important in tumor metastasis. Tumor cell tissue factor (TF) expression enhances metastasis and angiogenesis, and is primarily responsible for tumor-induced thrombin generation and the formation of tumor cell-platelet aggregates. Activated platelets express and release CD40 ligand (CD40L), which induces endothelial TF expression by ligation to CD40. We investigated the effect of platelet-derived CD40L on the TF activity of human CD40-positive melanoma cells and monocytes by incubating supernatants from activated or resting platelets with tumor cells or monocytes, and by bringing resting or activated platelets into close apposition with tumor cell monolayers. CD40L was present on the surface of activated (but not resting) platelets and was also released following platelet activation. Both recombinant soluble CD40L (rsCD40L) and activated platelet supernatants increased procoagulant activity (PCA) and TF antigen in tumor cells and monocytes. The increase in TF activity induced by both rsCD40L and activated platelet supernatants was inhibited by anti-CD40L antibody. Furthermore, contact of activated platelets with tumor cells increased cellular PCA, and this effect was also inhibited by anti-CD40L. In malignancy, the increase in cellular TF activity via CD40 (tumor cell)-CD40L (platelet) interaction may possibly enhance intravascular coagulation and hematogenous metastasis.

Changes of the coagulation and fibrinolysis system in malignancy: their possible impact on future diagnostic and therapeutic procedures

The interaction between malignant cell growth and the coagulation and fibrinolysis system has been a well known phenomenon for decades. During recent years, this area of research has received new attention. Experimental data suggest a role for the coagulation and fibrinolysis system in tumor development, progression and metastasis. Also, clinical research suggests that targeting the coagulation system or fibrinolysis system might influence the course of malignant disease beneficially. This paper reviews data on various hemostatic and fibrinolytic parameters in malignancy; the possible use of such parameters as risk markers in oncology patients; and possible targets of anti-neoplastic therapies using anticoagulant and/or antifibrinolytic strategies. Current evidence suggests that the tissue factor/factor VIIa pathway mediates the most abundant procoagulant stimulus in malignancy via the increase in thrombin generation. Tissue factor has been suggested to mediate pro-metastatic properties via coagulation-dependent and coagulation-independent pathways; tissue factor has also been implicated in tumor neo-angiogenesis. However, so far no model has been validated that would allow the use of tissue factor in its soluble or insoluble form as a marker for risk stratification in tumor patients. On the other hand, there is now good evidence that parts of the fibrinolytic system, such as urokinase-type plasminogen activator and its receptor ("uPAR"), can be used as strong predictors of outcome in several types of cancer, specifically breast cancer. Observation of various treatment options in patients with thromboembolic disease and cancer as well as attempts to use anticoagulants and/or therapies modulating the fibrinolytic system as anti-neoplastic treatment strategies have yielded exciting results. These data indicate that anticoagulant therapy, and specifically low molecular weight heparin therapy, is likely to have anti-neoplastic effects; and that their use in addition to chemotherapy will probably improve outcome of tumor treatment in certain types of cancer. However, the body of clinical data is still relatively small and the question whether or not we should routinely consider the coagulation and/or fibrinolysis system as therapeutic targets in cancer patients is yet to be answered.

Expression of thrombomodulin in squamous cell carcinoma of the lung: its relationship to lymph node metastasis and prognosis of the patients

Thrombomodulin (TM) is a type of thrombin receptor that was identified originally on the endothelium and acts as a natural anticoagulant through converting thrombin from a procoagulant protease to an anticoagulant. We reported previously that TM was also expressed in the squamous epithelium mainly at the intercellular bridges. In this study, we examined TM expression in the primary lesions of 81 patients with squamous cell carcinomas (SCCs) of the lung and in the lymph node metastatic lesions of 39 patients using immunohistochemical methods. The carcinoma tissues expressed TM mainly at the cell-cell boundaries and also in the cytoplasm. When TM expression was compared between the primary and metastatic lesions in the 39 patients who had lymph node metastasis, 26 (67%) showed decreased TM expression, 13 (33%) showed no change, and none (0%) showed an increase in the metastatic lesions. Wilcoxon's signed-rank test indicated that tumor cells that were positive for TM expression were significantly rarer in the metastatic lesions than in the primary tumors (P < 0.0001). The present study also showed that the patients with TM-negative expression in the primary tumors showed significantly poorer survival than those with TM-positive expression, mainly due to distant metastases of poorly-differentiated SCCs with negative TM expression in the primary tumors. These results indicate that the reduction of TM expression seems to play an important role in the metastatic process of lung SCCs.

Expression of tissue factor in non-small-cell lung cancers and its relationship to metastasis

Tissue factor (TF) is an initiator of the extrinsic cascade of blood coagulation. Although recent studies have revealed a relationship between metastatic properties and TF expression in some neoplastic cells, the significance of TF in lung cancer, especially in non-small-cell lung cancer (NSCLC), is still unclear. In this study, TF was detected in NSCLC cell lines by functional study, Western blot analysis and immunocytochemical staining. TF levels in eight NSCLC cell lines were also quantitated by enzyme-linked immunosorbent assay (ELISA), and TF expression was evaluated in 55 specimens of surgically resected NSCLCs. NSCLC cell lines derived from metastatic lesions produced high levels of TF (48.3+/-23.5 ng 10(-6) cells, mean +/- s.e.m.), whereas those derived from primary lesions produced low levels of TF (0.2+/-0.1 ng 10(-6) cells). Immunohistochemical studies disclosed significantly stronger staining for TF in cells from NSCLC patients with metastasis than in those without metastasis. Among the 28 patients with metastasis, ten were strongly positive, 16 were moderately positive and two were negative for TF. In contrast, among the 27 patients without metastasis, only two were strongly positive, 18 were moderately positive and seven were negative for TF. Therefore, malignant cells from patients with lung cancer produce various levels of TF, and TF may play an important role in the metastatic process.

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

The transcriptional localizations of urokinase-type plasminogen activator (uPA), its receptor (uPAR) and its inhibitors (PAI-1 and PAI-2), which are possibly involved in cancer metastasis, have not been determined in human lung cancer. To identify their regulation in primary non-small-cell lung cancer, we assayed mRNA levels by Northern blot analysis in 25 cases and determined the localizations of mRNA by in situ hybridization in 10 cases. The amounts of uPA and PAI-2 mRNA were significantly higher in cancerous relative to normal lung tissues. However, no significant difference was observed in uPAR and PAI-1 mRNA levels. All transcripts were present in cancer cells and were predominantly located in tumor edges in several cases. In addition, PAI-1 transcripts were more abundant in poorly and moderately differentiated carcinomas relative to well-differentiated carcinomas and PAI-2 transcripts were more abundant in squamous cell carcinomas than in adenocarcinomas. Thus, PAIs may be involved in modulation of malignant potency. Our results indicate that human non-small-cell lung cancer cells can autonomously express the mRNAs of uPA, uPAR and PAIs, which are possibly involved in metastasis.

Le(y) glycolipid acts as a co-factor for tumor procoagulant activity

We have generated a monoclonal antibody (MAb), FS01, which inhibits the procoagulant activity (CCA-1) produced by a human squamous cell carcinoma cell line, LK52. Expression of the antigen recognized by FS01 MAb in various cancer cell lines correlated well with the procoagulant activities of the expressing cell lines. Our objective was to characterize the molecule reacting with FS01 MAb and to analyze its involvement in the CCA-1 procoagulant activity. The molecule was identified as a glycolipid and found to be involved in the procoagulant activity because both procoagulant activity and reactivity to FS01 MAb were lost after endoglycoceramidase treatment of CCA-1. Furthermore, FS01 MAb recognized the Lewis Y (Le[y]) antigen. To confirm the involvement of a glycolipid incorporating the Le(y) antigen in the procoagulant activity, we attempted to purify CCA-1 from LK52 culture supernatant. In one of the purification steps, a fraction containing low procoagulant activity (CCA-1p) separated from the Le(y)-positive fraction (CCA-1c). Although CCA-1c alone did not show procoagulant activity, the procoagulant activity of CCA-1p was augmented by CCA-1c and this augmentation was inhibited by FS01 MAb. Furthermore, CCA-1c enhanced the procoagulant activity of 33 cell lines tested as well as CCA-1p. In addition, purified Le(y) glycolipid from canine intestine augmented the procoagulant activity of CCA-1p, and this augmentation also could be inhibited by FS01 MAb. We conclude that Le(y) glycolipid is a co-factor for the procoagulant activity derived from cancer cells.

The urokinase-type plasminogen activator system in cancer metastasis: a review

The urokinase-type plasminogen activator (u-PA) system consists of the serine proteinases plasmin and u-PA; the serpin inhibitors alpha2-anti-plasmin, PAI-1 and PAI-2; and the u-PA receptor (u-PAR). Two lines of evidence have strongly suggested an important and apparently causal role for the u-PA system in cancer metastasis: results from experimental model systems with animal tumor metastasis and the finding that high levels of u-PA, PAI-1 and u-PAR in many tumor types predict poor patient prognosis. We discuss here recent observations related to the molecular and cellular mechanisms underlying this role of the u-PA system. Many findings suggest that the system does not support tumor metastasis by the unrestricted enzyme activity of u-PA and plasmin. Rather, pericellular molecular and functional interactions between u-PA, u-PAR, PAI-1, extracellular matrix proteins, integrins, endocytosis receptors and growth factors appear to allow temporal and spatial re-organizations of the system during cell migration and a selective degradation of extracellular matrix proteins during invasion. Differential expression of components of the system by cancer and non-cancer cells, regulated by paracrine mechanisms, appear to determine the involvement of the system in cancer cell-directed tissue remodeling. A detailed knowledge of these processes is necessary for utilization of the therapeutic potential of interfering with the action of the system in cancers.

Levels of plasminogen activator inhibitor type 1 and urokinase plasminogen activator receptor in non-small cell lung cancer as measured by quantitative ELISA and semiquantitative immunohistochemistry

The components of the plasminogen activation system have been reported to have prognostic impact in several cancer types, e.g. breast-, colon-, gastric- and lung cancer. Most of these studies have used quantification by enzyme-linked immunosorbent assay (ELISA) on tumour tissue extracts. However, results in non-small cell lung cancer (NSCLC) studies obtained by quantitative ELISA and semiquantitative immunohistochemistry differ. If the prognostic value of the components of the plasminogen activation system is to be exploited clinically in the future, it is important to choose an easy and valid methodology. In the present study we investigated levels of plasminogen activator inhibitor type 1 (PAI-1) and urokinase plasminogen activator receptor (uPAR), as quantitated by ELISA in tumour extracts from 64 NSCLC patients (38 squamous cell carcinomas, 26 adenocarcinomas), and compared them to staining intensity as semiquantitated by immunohistochemistry for PAI-1 and uPAR on corresponding cryostat sections. A significant association (r = 0.49, P < 0.0001) was found between the PAI-1 levels measured by ELISA and semiquantitated by immunohistochemistry. No association was found for uPAR. When correlating levels of PAI-1 and uPAR determined by ELISA and immunohistochemistry, respectively, to survival status, no significant correlation was found for any of the subgroups. At present neither of the methods examined in the present study can be recommended as superior for quantitating PAI-1 and uPAR with the aim of predicting prognosis. In conclusion, a larger comparative study is needed to clarify the relationship between ELISA and immunohistochemical results, before a methodology for clinical use can be chosen in non-small cell lung cancer.

Expression and localization of thrombomodulin in preneoplastic bronchial lesions and in lung cancer

Thrombomodulin (TM) is an endothelial surface glycoprotein that acts as a natural anticoagulant. It inhibits thrombin and accelerates the activation of the anticoagulant protein C. TM has been detected in dermal keratinocytes, where it is associated with terminal differentiation. It can also be detected in various types of squamous malignant neoplasms and in malignancies of endothelial and mesothelial origin, such as Kaposi's sarcoma or malignant mesothelioma, but is absent in pulmonary adenocarcinomas (AC). Seventy-two lung tumour specimens [33 squamous cell carcinomas (SQCC), 23 AC, 1 large cell carcinoma, 8 small cell lung cancers (SCLC) and 7 multidifferentiated tumours (MT)] were analysed immunohistochemically by staining with an anti-TM antibody in order to assess TM expression. All of the SQCC stained positively for TM. In contrast, only 9 AC and 4 MT and none of the SCLC showed positive anti-TM staining. Seven hyperplastic bronchial epithelial specimens and eight preneoplastic bronchial lesions (five cases of moderate dysplasia, two cases of severe dysplasia and one case of carcinoma in situ) were used as controls. Normal or hyperplastic areas of bronchial epithelium revealed no positive reaction. However, a distinct positive anti-TM staining pattern related to the degree of keratiniziation of dysplastic lesions was seen. The present results suggest that anti-TM immunostaining is a useful marker for squamous cell carcinoma in the differential diagnosis of pulmonary carcinoma, also indicating keratinocyte differentiation in dysplastic bronchial epithelium.

Determination of tumor cell procoagulant activity by Sonoclot analysis in whole blood

Coagulation activation in cancer may be due to expression of procoagulant activity (PCA) by tumor cells. Some PCA activate coagulation, while others influence platelet aggregation. Thus, clotting time assessments of PCA may not reflect the potential for hypercoagulability. We therefore studied the effect of various malignant and non-malignant cells on whole blood coagulation using the Sonoclot Analyzer. Five human (HT29 colon, J82 bladder, MCF-7 breast, BT-474 breast and A375 malignant melanoma) and three rodent (MC28, WEHI-164 and Neuro2a) cell lines were used. Rat thymocytes and peritoneal macrophages and human endotoxin-stimulated mononuclear cells and umbilical vein endothelial cells (HUVEC) were used as non-malignant controls. All tumor cells markedly shortened the recalcification time of citrated blood and the most potent (HT29 and J82) also increased clot rate (P < 0.01). The breast cancer cells MCF-7 and BT-474 expressed only weak PCA and did not affect clotting rate. None of the non-malignant cells significantly affected clotting time or rate in whole blood. J82 and HT29 cells grown in serum-rich media shortened the recalcification time of both normal and FVII-deficient plasmas. However, cells grown in serum-free conditions had significantly less PCA in FVII-deficient plasma. We conclude that the Sonoclot Analyzer is useful for determining cellular PCA; significant PCA is a feature of malignant cells and cells grown in medium containing serum supplements cannot be reliably evaluated for PCA.

Studies on tumor-cell-induced platelet aggregation in human lung cancer cell lines

We investigated the ability of human lung cancer cells of different histological subtypes to cause platelet aggregation. Tumor-cell-induced platelet aggregation (TCIPA) was studied in vitro in 13 human lung cancer cell lines [small-cell lung cancer (SCLC), squamous-cell lung cancer, large-cell lung cancer, adenocarcinoma and alveolar-cell lung cancer]. Three tumor cell lines failed to aggregate platelets in platelet-rich plasma, whereas platelet aggregation was induced by 12 cell lines when added to washed platelets and minimal amounts of platelet-poor plasma (0.5% v/v). The thrombin antagonist hirudin inhibited TCIPA in non-small-cell lung cancer cell lines (NSCLC). In SCLC, TCIPA was fully abolished only when the ADP scavenger apyrase was added to hirudin. Thus ADP and thrombin generation by these tumor cell lines are responsible for platelet aggregation. The ability to activate platelets independently of coagulation factors VII and X was demonstrated for 8 cell lines. Electron-microscopically, direct tumor-cell/platelet contact was found to be the initiating mechanism of TCIPA in SCLC, whereas tumor-cell/platelet contacts in NSCLC could only be observed at the peak of the aggregation curve. Lung cancer cells activate platelets in vitro by generation of thrombin and/or ADP.

Detection of malignant tumors using Tc-99m labeled Fab' fragments from a monoclonal antibody with specificity for D-dimer of cross-linked fibrin

The authors present the case studies of two patients whose malignant tumors were detected with a Tc-99m labeled antifibrin monoclonal antibody (DD-3B6/22), which is specific for cross-linked fibrin. The first case was a malignant fibrous histiocytoma involving the proximal aspect of the left thigh, whereas in the second case, the patient was receiving treatment for a squamous cell carcinoma of the right mainstem bronchus. The results highlight the potential of this anti-D-dimer radiopharmaceutical for noninvasive detection of malignant tumors.

High plasma level of plasmin-alpha 2-plasmin inhibitor complex is predictor of poor prognosis in patients with lung cancer

The occurrence of thrombotic complications is commonly associated with poor prognosis in patients with malignancy. However, the prognostic significance of the subclinical activation of the clotting system, frequently observed in cancer patients, is unknown. The purpose of the present study was to evaluate the value of the pre-thrombotic state for predicting survival of lung cancer patients. This investigation comprised 70 lung cancer patients without clinical or laboratory diagnosis of intravascular coagulation. There were 49 cases with non-small and 21 with small cell carcinomas. Samples taken in controls were available for comparison. The clotting system was assessed measuring thrombin-antithrombin III complex (TAT) and plasmin-alpha 2-plasmin inhibitor complex (PAP). The independent value of these clotting markers to predict survival was evaluated in relation with previously well-established prognostic factors for lung cancer patients. Plasma concentration of each parameter was significantly higher in cancer patients as compared to that of controls. The plasma level of PAP was a predictor of survival independently from the stage of disease, sex, age, histological type, performance status, tumor size and the presence of distant metastasis. Discriminant analysis of PAP plasma concentration identified 2 groups with significant difference in survival rate in all patients, cases in advanced stages of disease and in those with small and non-small cell lung cancer. The results of the present study showed prognostic significance of the subclinical activation of the clotting system, particularly of the fibrinolytic pathway, in lung cancer. Newly developed markers of fibrinolysis might be potentially applicable for predicting outcome in malignancy.

The plasminogen activation system and its role in lung cancer. A review

The urokinase pathway of the plasminogen activation is involved in proteolytic degradation of various tissues, including dissolution of the extracellular matrix and basement membranes during the process of cancer cell invasion. Recent studies have demonstrated that components of the plasminogen activation system have a prognostic impact in breast-, lung-, colorectal, bladder and gastric cancer. A number of studies, reviewed here, have focused on the role of the plasminogen activation system in different lung cancer types. There seems to be an obvious difference between the expression, localization and prognostic impact of the components of the plasminogen activation system in different lung cancer types. The differences seen could be helpful in understanding the biology of different lung cancer types, and components of the plasminogen activation system may have prognostic relevance and clinical implications in some lung cancer types, even though confirmatory studies are needed.

Inactive urokinase and increased levels of its inhibitor type 1 in colorectal cancer liver metastasis

BACKGROUND/AIMS

Human colorectal carcinogenesis was previously found to be associated with an increased urokinase-type plasminogen activator expression, both in antigen and activity, accompanied by simultaneously enhanced levels of plasminogen activator inhibitors type 1 and type 2. This increased proteolytic activity may contribute to invasive growth and metastasis of the tumors.

METHODS

In the present study, homogenates of liver metastases, primary colorectal carcinomas, and adjacent normal tissues were evaluated regarding the level and composition of urokinase, tissue-type plasminogen activator, and plasminogen activator inhibitors.

RESULTS

Concentrations of urokinase were significantly increased in primary carcinomas and liver metastases compared with normal tissues, whereas tissue-type plasminogen activator levels were significantly decreased. Liver metastases showed, in contrast to the carcinomas, hardly any activity of plasminogen activators, which could be attributed to the enhanced presence of the inactive proenzyme form of urokinase in combination with more complexes of plasminogen activators with inhibitors. Furthermore, liver metastases had an eightfold higher content of inhibitor type 1 compared with the primary carcinomas. The excess of inhibitors was confirmed by addition of plasminogen activators to metastasis homogenates, which resulted in increased complex formation.

CONCLUSIONS

Colorectal cancer metastasis in the liver is associated with an inactivation of the enhanced urokinase cascade, which might allow tumor cells to settle in the liver.

Procoagulant activity of the MC28 fibrosarcoma cell line in vitro and in vivo

Experimental evidence suggests that many tumours can activate blood coagulation and that such interaction is part of the pathology of metastatic tumour growth. This study aimed to study the procoagulant activity of the methylcholanthrene-induced (MC28) fibrosarcoma to determine whether coagulation activation by these cells could explain the previously reported effects of oral anticoagulants on lung seeding in this model. MC28 cells shortened the recalcification times of normal and factor VII-deficient plasma and directly activated factor X in a chromogenic assay, but did not aggregate platelets in vitro in either whole blood or platelet-rich plasma. Cellular coagulant activity was calcium-dependent, blocked by DFP and concanavalin A but not inhibited by iodoacetamide, E-64 or antibodies to human tissue factor or factor VII. Injection of viable MC28 cells into hooded Lister rats induced a decrease in platelet count (P < 0.001), plasma factor X (P < 0.001) and fibrinogen (P < 0.05) and a marked increase in plasma haemoglobin (P < 0.001). These effects were either not observed or were considerably less marked in heparinized or warfarinized animals. Injection of MC28 cells treated with concanavalin A in vitro completely abolished the clotting changes observed with untreated cells. In conclusion, MC28 cells possessed a potent factor X-activating serine proteinase procoagulant in vitro, which had some of the characteristics of a tissue factor/factor VIIa complex. In vivo, MC28 cells caused clotting activation and intravascular fibrin generation. Since thrombocytopenia was abolished by heparin and the cells lacked platelet aggregating activity in vitro, thrombocytopenia was probably secondary to intravascular coagulation and thrombin generation. The trigger for intravascular clotting activation appeared to be the cellular procoagulant activity since it was abolished by prior in vitro blockade of the latter with concanavalin A.

Correlation between increased granulocyte elastase release and activation of blood coagulation in patients with lung cancer

BACKGROUND

Coagulopathies often are associated with malignant tumors. The pathogenesis of these complications in cancer is not clear. Host inflammatory (monocyte/macrophage) cell-mediated triggering of clotting activation has been suggested.

METHODS

The objective of this study was to evaluate the role of neutrophil-derived elastase in the activation of blood coagulation and fibrinolysis in lung cancer. The study population was 42 consecutive patients with lung cancer (34 men and 8 women). Thirteen patients had small cell lung cancer (SCLC), 13 had squamous cell lung cancer, and 16 had adenocarcinoma. Hemostatic function was assessed by measuring D-dimer (DD), thrombin-antithrombin III complex (TAT), plasmin-alpha 2-antiplasmin complex (PAP), fibrin degradation product (FDP), fibrinogen, prothrombin time (PT) and activated partial thromboplastin time (APTT). Elastase-alpha 1-protease inhibitor (EPI) complex was measured as a marker of neutrophil activation.

RESULTS

Significant elevation of the elastase plasma levels and coagulation-fibrinolysis parameters was found in patients with cancer compared with control subjects. Among all patients, the plasma concentration of EPI was significantly correlated with APTT, DD, TAT, PAP, and fibrinogen. Although in patients with non-small cell lung cancer (non-SCLC), DD, TAT, PAP, APTT, and fibrinogen were significantly correlated with EPI, such a correlation was not found in patients with SCLC. Patients with non-SCLC had stronger correlation of EPI with TAT, PAP, and PT than did patients with advanced stages of disease.

CONCLUSION

The activation of coagulation-fibrinolysis system in lung cancer may be triggered, at least in part, by an increased release of neutrophil elastase. This mechanism is stage related and seems to operate predominantly in non-SCLC.

Immunohistochemical study of tumor cell-associated plasminogen activators and plasminogen activator inhibitors in lung carcinomas

STUDY OBJECTIVE

To compare the expression of plasminogen activators (PA) and plasminogen activator inhibitors (PAI) in normal lung mucosa and lung carcinomas.

DESIGN

Immunohistochemical localization of urokinase-type PA (uPA), tissue-type PA (tPA), type 1 PAI (PAI-1), and type 2 PAI (PAI-2) in four normal lung biopsy specimens and in four adenocarcinomas (AC), four squamous carcinomas (SC), two large-cell carcinomas (LCC), and ten small-cell carcinomas (SCC) biopsy specimens. Qualitative immunostaining scoring system.

RESULTS

tPA and uPA immunostaining scores from all specimens were statistically similar. The cellular staining for uPA and tPA was generally constant (normal epithelial layers, AC cells, SC cells) except for LCC cells (inconstant uPA staining, p < 10(-3). Both PAIs were detected in cells of the normal epithelial layer. The four carcinoma cell types stained for PAI in a statistically different pattern (p < 10(-3)). Cells of the peripheral cords of SCC were inconstantly PAI-1 and PAI-2 positive (p < 10(-3)). LCC were PAI-2 negative and inconstantly stained for PAI-1. SCC cells were PAI-1 and PAI-2 negative.

CONCLUSION

Lung carcinomas of worst clinical prognosis no longer express PAI reactivity. The imbalance of the plasminogen activation pathway may favor the spreading of the more invasive histologic types of bronchogenic carcinomas.

Urinary tissue factor levels in prostatic carcinoma: a potential marker of metastatic spread?

Recent investigations have suggested that levels of urinary tissue factor (UTF) may be elevated in some forms of cancer. We have determined UTF levels in healthy controls, patients presenting for surgery with benign prostatic hypertrophy (BPH) and untreated prostate cancer. Patients undergoing check cystoscopy, who were free of recurrent bladder cancer, and a cohort of men with bone scan positive prostate cancer recently treated by androgen ablation were also studied. UTF levels were higher in patients with prostate cancer when compared with controls, those undergoing check cystoscopy and patients with BPH. In patients with prostate cancer, bone scan positive patients had higher levels than bone scan negative subjects. The androgen ablated group had UTF levels similar to those of the control groups and significantly lower than the bone scan positive group. A weak correlation was found between UTF and serum prostate specific antigen (PSA) levels when patients with BPH and untreated cancer were analysed, but no correlation was demonstrable between PSA and UTF when cancer patients alone were evaluated. It was concluded that UTF levels are elevated in untreated prostate cancer and reflect bone scan status. In patients with bone scan positive disease UTF also reflects disease activity and may therefore be a useful disease marker in prostate cancer.

The effect of local immunotherapy for breast cancer using a mixture of OK-432 and fibrinogen supplemented with activated macrophages

OK-432 is an immunomodulatory agent prepared from a strain of Streptococcus pyogenes. We have previously reported that intratumoral injection of a mixture of OK-432 and fibrinogen (hereinafter referred to as OK/fbg) is very effective in the local immunotherapy for colorectal cancer. However, we found that the intratumoral injection of OK/fbg into tumor tissues of breast cancers did not always induce a strong antitumor effect. With conventional OK/fbg treatment, tumor necrosis observed in breast cancer tumors was significantly less than that in colorectal cancer tumors; the formation of fibrin meshwork and macrophage infiltration, in particular, were poor. In this study, the OK/fbg mixture was supplemented with activated macrophages for local immunotherapy of breast cancers. Macrophages were prepared from peripheral blood of breast cancer patients and activated with 0.05 mg/ml of OK-432. Between 2-7 days before operation, a single intratumoral injection of the above mixtures was done. The addition of activated macrophages to the OK/fbg mixture resulted in marked degrees of fibrin meshwork formation, macrophage infiltration and cancer cell necrosis. These findings suggest that the recruitment of macrophages in tumor stroma and their activation are necessary for sufficient induction of antitumor immunity, and supplementation of activated macrophages at the site of immune reaction may be an alternative method for reinforcement of the antitumor effect of local immunotherapy.

The role of fibrin in tumor metastasis

A volume of data that has accumulated for over a century has suggested that fibrin may facilitate the persistence and progression of malignancy. Techniques that have been developed recently have shown that fibrin is indeed a component of the connective tissue stroma in human malignancy but in only a few tumor types. However, therapeutic intervention studies with drugs that limit thrombin activity or enhance fibrinolysis have shown favorable clinical effects in at least one such tumor type. These favorable findings affirm the concept that cause-and-effect relationships do, in fact, exist between thrombin generation with fibrin formation and tumor progression, and suggest that a rational basis exists for the design of future drug intervention trials that target reactions relevant to specific tumor types. These findings also provide a basis for the design of experiments capable of defining further the role of fibrin in the integrity of these tumor types. Because fibrinogen is found much more commonly than fibrin in the connective tissue of a variety of human malignancies, attention might reassumably be directed to determining the possible contribution of this molecule as well as of fibrin to tumor progression.

Tissue factor as a tumor procoagulant

Tissue factor is a cell surface glycoprotein responsible for initiating the extrinsic pathway of coagulation. Many tumor cell homogenates and intact tumor cells have been shown to contain tissue factor activity. Immunohistochemical studies show that many tumors associated with Trousseau's syndrome express tissue factor on their cell surfaces. Tumor cells shed membrane fragments which carry tissue factor that can account for the activation of the clotting system. Tumor cells also produce soluble substances that can induce tissue factor expression on host cells, such as endothelium and monocytes, at sites distant from the tumor. Although, all the functional TF molecules are localized on the outer cell membrane in many tumor cells, the procoagulant activity on the intact cell surface is largely dormant and can be greatly enhanced upon cell injury or damage. Tissue factor procoagulant activity on the cell surface can be modulated by alterations in the plasma membrane without loss of cell viability. Tissue factor activity on cell surfaces is largely regulated by a plasma inhibitor, tissue factor pathway inhibitor. This inhibitor binds to both functional and non-functional tissue factor/VIIa complexes on the cell surface and prevents non-functional tissue factor/VIIa complexes from becoming functional after cell injury or lysis. Heparin, but not warfarin, therapy is effective in preventing the occurrence of devastating thrombotic events in patients with Trousseau's syndrome and the reason(s) for this are still unknown.

The effect of Warfarin and factor VII on tissue procoagulant activity and pulmonary seeding

Peri-tumour fibrin is a consistent feature of tumour stroma and is deposited shortly after tumour cell inoculation. Since there are several ways in which fibrin may be beneficial to tumour growth, it is possible that the ability of normal or malignant tissue to generate fibrin may influence metastasis. Many normal tissues and tumour cells possess a procoagulant activity that is due to a complex of tissue factor and factor VII. We have measured this tissue procoagulant activity in normal rats, rats stabilised on Warfarin and similarly anticoagulated animals injected with factor VII. The effect of Warfarin and factor VII administration on pulmonary seeding following injection of MC28 fibrosarcoma cells was also assessed. Procoagulant activity in adrenal, lung and colon was significantly reduced by Warfarin (P less than 0.001). Administration of factor VII significantly increased lung and adrenal tissue procoagulant activity in anticoagulated rats (P less than 0.02). Warfarinised rats had significantly slower primary tumour growth (P less than 0.001) and fewer lung deposits than control animals (P less than 0.001). Injection of factor VII restored pulmonary seeding to control levels (P less than 0.001). Warfarin did not affect the ability of the cells to adhere in vitro and did not reduce the number of tumour cells physically trapped in the lungs after intravenous injection. It is concluded that the procoagulant activity of normal tissues may influence their ability to support tumour growth and that the antimetastatic effect of Warfarin may be at least partly due to a reduction in the availability of the factor VII required for this activity.