Angiogenic activity as a marker of neoplastic and preneoplastic lesions of the human bladder

Review : Angiogenesis: A new target for antineoplastic therapy

Objective. To review the pathophysiologic rationale and therapeutic applications of inhibiting angiogenesis in solid tumor growth.

Data Sources. A MEDLINE search of articles published from 1985 to 1995 and a CancerLit search of articles published from 1988 to 1995, using the MESH heading "neovascularization" and text words "angiogenesis" and "antiangiogenesis." References listed in identified publications were reviewed for additional pertinent literature.

Study Selection. All human trials evaluating angiogenesis inhibitors in malignant disease and pre- clinical trials that illustrate potential mechanisms of action of such agents were included.

Data Synthesis. Angiogenesis, the formation of new blood vessels, is necessary for the development of significant solid tumor growth. Inhibition of angio genesis is a unique mechanism of antineoplastic ther apy that does not use traditional cytotoxic actions. Four investigational antiangiogenic agents are cur rently being evaluated in phase I and II trials. Poten tially beneficial applications of angiogenesis inhibitors include suppression of occult and premalignant le sions, symptomatic control of angiogenesis-depen dent malignancies, and combination therapy with traditional antineoplastic agents.

Conclusion. Inhibition of angiogenesis is a new pharmacologic strategy that may prove useful in controlling malignant growth. A number of agents with antiangiogenic activity have been developed, and further study of these drugs will define their role in antineoplastic therapy.

Antiangiogenesis as the novel mechanism for justicidin A in the anticancer effect on human bladder cancer

Justicidin A (JA) is one of the methanol extracts of Justicia procumbens and was reported to induce apoptosis and inhibit the proliferation of human colon cancer cells. Using bladder cancer as a paradigm, this study was designed to identify the novel molecular basis underlying the antiangiogenic activities of JA and its potential in cancer therapy. Human bladder cancer cell lines (TSGH8301 and RT4) and immortalized uroepithelial cell lines (E6 and E7) were chosen to investigate the efficacy of JA in cell proliferation, apoptosis, and angiogenesis in vitro. The biological effects of JA treatment in vivo were examined using a xenograft tumor model in SCID mice. JA showed a dose-dependent and time-dependent inhibition of cell proliferation on TSGH8301 cancer cells, with IC50 values determined to be 0.44 μmol/l. Of interest, TSGH8301 cancer cells were more sensitive to JA than E7 immortalized uroepithelial cells, especially at lower concentrations. We further showed that JA inhibited the autocrine production of angiogenic factors and matrix-degrading enzymes in vitro and microvessel density in SCID mice in vivo (P< 0.01). Both differential cytotoxicity and angiogenesis inhibition of JA were confirmed by SCID mice experiments. Together, JA showed antiangiogenesis in vitro and in vivo through pleiotropic positive and negative regulators of angiogenesis molecules. The current investigation supports the potential of JA as an alternative chemoprevention agent for human bladder cancer.

Nanocarrier mediated delivery of siRNA/miRNA in combination with chemotherapeutic agents for cancer therapy: current progress and advances

Chemotherapeutic agents have certain limitations when it comes to treating cancer, the most important being severe side effects along with multidrug resistance developed against them. Tumor cells exhibit drug resistance due to activation of various cellular level processes viz. activation of drug efflux pumps, anti-apoptotic defense mechanisms, etc. Currently, RNA interference (RNAi) based therapeutic approaches are under vibrant scrutinization to seek cancer cure. Especially small interfering RNA (siRNA) and micro RNA (miRNA), are able to knock down the carcinogenic genes by targeting the mRNA expression, which underlies the uniqueness of this therapeutic approach. Recent research focus in the regime of cancer therapy involves the engagement of targeted delivery of siRNA/miRNA in combinations with other therapeutic agents (such as gene, DNA or chemotherapeutic drug) for targeting permeability glycoprotein (P-gp), multidrug resistant protein 1 (MRP-1), B-cell lymphoma (BCL-2) and other targets that are mainly responsible for resistance in cancer therapy. RNAi-chemotherapeutic drug combinations have also been found to be effective against different molecular targets as well and can increase the sensitization of cancer cells to therapy several folds. However, due to stability issues associated with siRNA/miRNA suitable protective carrier is needed and nanotechnology based approaches have been widely explored to overcome these drawbacks. Furthermore, it has been univocally advocated that the co-delivery of siRNA/miRNA with other chemodrugs significantly enhances their capability to overcome cancer resistance compared to naked counterparts. The objective of this article is to review recent nanocarrier based approaches adopted for the delivery of siRNA/miRNA combinations with other anticancer agents (siRNA/miRNA/pDNA/chemodrugs) to treat cancer.

Tumor angiogenesis as a target for dietary cancer prevention

Between 2000 and 2050, the number of new cancer patients diagnosed annually is expected to double, with an accompanying increase in treatment costs of more than $80 billion over just the next decade. Efficacious strategies for cancer prevention will therefore be vital for improving patients' quality of life and reducing healthcare costs. Judah Folkman first proposed antiangiogenesis as a strategy for preventing dormant microtumors from progressing to invasive cancer. Although antiangiogenic drugs are now available for many advanced malignancies (colorectal, lung, breast, kidney, liver, brain, thyroid, neuroendocrine, multiple myeloma, myelodysplastic syndrome), cost and toxicity considerations preclude their broad use for cancer prevention. Potent antiangiogenic molecules have now been identified in dietary sources, suggesting that a rationally designed antiangiogenic diet could provide a safe, widely available, and novel strategy for preventing cancer. This paper presents the scientific, epidemiologic, and clinical evidence supporting the role of an antiangiogenic diet for cancer prevention.

Tumor cell-derived PDGF-B potentiates mouse mesenchymal stem cells-pericytes transition and recruitment through an interaction with NRP-1

Background

New blood vessel formation, or angiogenic switch, is an essential event in the development of solid tumors and their metastatic growth. Tumor blood vessel formation and remodeling is a complex and multi-step processes. The differentiation and recruitment of mural cells including vascular smooth muscle cells and pericytes are essential steps in tumor angiogenesis. However, the role of tumor cells in differentiation and recruitment of mural cells has not yet been fully elucidated. This study focuses on the role of human tumor cells in governing the differentiation of mouse mesenchymal stem cells (MSCs) to pericytes and their recruitment in the tumor angiogenesis process.

Results

We show that C3H/10T1/2 mouse embryonic mesenchymal stem cells, under the influence of different tumor cell-derived conditioned media, differentiate into mature pericytes. These differentiated pericytes, in turn, are recruited to bind with capillary-like networks formed by endothelial cells on the matrigel under in vitro conditions and recruited to bind with blood vessels on gel-foam under in vivo conditions. The degree of recruitment of pericytes into in vitro neo-angiogenesis is tumor cell phenotype specific. Interestingly, invasive cells recruit less pericytes as compared to non-invasive cells. We identified tumor cell-secreted platelet-derived growth factor-B (PDGF-B) as a crucial factor controlling the differentiation and recruitment processes through an interaction with neuropilin-1 (NRP-1) in mesenchymal stem cells.

Conclusion

These new insights into the roles of tumor cell-secreted PDGF-B-NRP-1 signaling in MSCs-fate determination may help to develop new antiangiogenic strategies to prevent the tumor growth and metastasis and result in more effective cancer therapies.

Angiogenesis in pre-malignant conditions

Angiogenesis is an essential process involved in the normal growth and differentiation. In its defective and excessive form, angiogenesis is a crucial event in the progression of many human diseases. Excessive angiogenesis was largely investigated in psoriasis, arthritis, diabetic retinopathy and malignant tumours. Soon after the discovery of angiogenic factors and their inhibitors, the angiogenesis jumped from the experimental studies to clinical application. Tumour-associated angiogenesis is nowadays considered as a priority in oncology based on numerous evidences that showed a significant reduction in tumour growth following anti-angiogenic therapy. However, few data are available on pre-malignant conditions. First evidences on angiogenesis in pre-malignant lesions came from the evaluation of microvessel density (MVD). MVD was found to be significantly increased in a relatively large spectrum of pre-malignant squamous cell lesions, such as in the oral mucosa, skin, uterine cervix, vulva and anal canal. For many of them, a correlation was found between MVD and the expression of vascular endothelial growth factor (VEGF). Based on these data, it was suggested that tumour angiogenesis is not necessarily a characteristic of invasive tumour, but may be an early event during tumourigenesis. Additional evidences came from pre-malignant lesions of glandular epithelia, in which the angiogenic switch was demonstrated by the immunohistochemical expression of VEGF in gastric metaplasia and dysplasia, in atypical adenoma of the colon, atypical hyperplasia and carcinoma in situ of the breast and others. Actually, there are convincing evidences for an active angiogenesis in many cases with pre-malignant conditions, and this supports a more accurate evaluation of different chemopreventive agents.

The scientific contributions of M. Judah Folkman to cancer research

Dr Judah Folkman was frequently described as a highly compassionate physician who served his patients not only by performing surgery and offering them comfort and reassurance, but also by working tirelessly in the laboratory to find new approaches to the treatment of disease. His dedication to understanding the role of angiogenesis, the formation of new blood vessels, in human disease has given rise to new treatments for several diseases, including inflammatory diseases, vision-threatening diseases of the eye and, as will be emphasized in this Perspective, cancer.

Dynamic Contrast-Enhanced MRI of Malignant Pleural Mesothelioma

STUDY OBJECTIVE

Dynamic contrast-enhanced MRI (DCE-MRI) followed by pharmacokinetic analysis has been successfully used in a variety of solid tumors. The aims of this study were to evaluate the feasibility of DCE-MRI in malignant pleural mesothelioma (MPM), to differentiate benign from pathologic tissue and compare pharmacokinetic with clinical parameters and survival in order to map out its microcirculation; and to compare pharmacokinetic with clinical parameter and survival in order to improve our understanding of the in vivo biology of this malignancy.

METHODS

Nineteen patients with a diagnosis of MPM who were scheduled to receive chemotherapy with gemcitabine were enrolled in the study. DCE-MRI was performed before treatment (n = 19) and after the third cycle (n = 12) and sixth cycle (n = 7) of chemotherapy. An established pharmacokinetic two-compartment model was used to analyze DCE-MRI. Tumor regions were characterized by the pharmacokinetic parameters amplitude (Amp), redistribution rate constant (kep), and elimination rate constant (kel). Kinetic parameters of tumor tissue and normal tissue were compared using the Student t test. Patients were classified as clinical responders or nonresponders according to clinical outcome, and these groups were compared with the pharmacokinetic parameters derived from DCE-MRI.

RESULTS

Normal and tumor tissue could be distinguished by the pharmacokinetic parameters Amp and kel (p </= 0.001). Clinical responders had a median kep value within the tumor of 2.6 min, while nonresponders showed a higher value (3.6 min), which coincided with longer survival (780 days vs 460 days).

CONCLUSIONS

DCE-MRI can be used in patients with MPM to assess tumor microvascular properties and to demonstrate tumor heterogeneity for therapy monitoring. High pretherapeutic values of kep within the tumor correlated with a poor overall response to therapy.

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.

Significance of microvascular density (MVD) in cervical cancer recurrence

The purpose of this retrospective study of 118 patients with squamous cell cervical cancer from January 1990 to December 1993 was to evaluate angiogenesis as predictive factor of recurrence in cervical cancer stages II-III treated with standard radiotherapy. Microvessel density (MVD) was evaluated and correlated with other prognostic factors. MVD was greater than 20 in 67.8% of patients with recurrence (P = 0.002) in comparison to 39% of patients without. Disease-free survival was shorter in stage IIA and MVD >20 (P = 0.0193) as well as for stage IIB (P < 0.05 ), but not for IIIB (P = 0.1613 ). Global survival was significantly shorter when MVD was >20 (P = 0.0316). For stage IIA and MVD >20 survival was shorter (P = 0.0008) for stage IIB (P < 0.05) but not for IIIB (P = 0.14). Patients younger than 40 years and MVD >20 had poorer disease-free interval and survival (P = 0.0029). MVD in patients with squamous cell cervical cancer stage II and age younger than 40 may play a role in predicting recurrence and survival.

Novel approaches with targeted therapies in bladder cancer. Therapy of bladder cancer by blockade of the epidermal growth factor receptor family

The improved understanding of the molecular biology of urothelial malignancies is helping to define the role of new targets and prognostic indices that can direct the most appropriate choice of treatment for advanced disease. Many human tumors express high levels of growth factors and their receptors that can be used as potential therapeutical targets. Tyrosine-kinase receptors, including many growth factor receptors such the receptors for epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), and Her2/neu, have been found overexpressed in urothelial tumors. For many of these growth factor receptors, the degree of expression has been associated with the progression of cancer and a poor prognosis. Among the best studied growth factor receptors are the two members of EGF receptor familiy EGFr (ErbB-1), and Her2/neu (ErbB-2). Several preclinical studies in bladder cancer models, have confirmed that systemic administration of growth factor inhibitors inhibits the growth and metastasis of human transitional cell carcinoma established in the bladder wall of athymic nude mice. Additional studies indicate that therapy with EGFR inhibitors enhances the activity of conventional cytoreductive chemotherapeutic agents, in part by inhibiting tumor cell proliferation, angiogenesis, and inducing apoptosis. Novel targeted therapy hold promise to improve the current results of bladder cancer treatment. Based on the success seen with anti-HER2 monoclonal antibodies (Herceptin) and the promising results with EGFR targeted agents (IMC-C225 Cetuximab, ZD1389 Iressa, OSI-774 Tarceva, GW 57016) in other tumor types, and based on the results obtained in preclinical models, there is a great interest in assessing these agents in patients with bladder cancer. Several trials are now ongoing testing these new agents alone or in combination with chemotherapy in bladder cancer patients. The integration of these newer biologic agents, probably to supplement rather than to supplant chemotherapeutic drugs, should be a primary direction of research with the objective to interfere with multiple aspects of bladder cancer progression. However, the value of integration of biologically targeted agents into combined modality treatment for patients with bladder cancer has still to be proven.

Thrombospondin 1 protein expression relates to good prognostic indices in ductal carcinoma in situ of the breast

AIM

Angiogenesis plays an important role in tumour growth and has been shown to occur around both in situ and invasive tumours. The degree of angiogenesis within tumours depends on the balance of pro-angiogenic and anti-angiogenic factors. One such anti-angiogenic factor is thrombospondin 1 (TSP-1). This study investigates the pattern of expression of TSP-1 in ductal carcinoma in situ (DCIS) of the breast and its relation to the surrounding microvessel pattern and density.

MATERIALS/METHODS

The expression of TSP-1 was studied in formalin fixed, paraffin wax embedded sections from 58 cases of pure DCIS, using a monoclonal antibody against TSP-1 and the avidin-biotin-diaminobenzidine immunoperoxidase detection system. Vessels were stained with a monoclonal antibody to the endothelial cell marker CD31. Stromal microvessel density was assessed by counting "hot spots" within 500 micro m of the basement membrane of involved ducts using a 25 point Chalkey graticule.

RESULTS

TSP-1 staining of the basement membrane around duct spaces with DCIS was seen in 69% of cases. In addition, staining of the stroma between involved duct spaces was seen in 31% of cases, with a fibrillary pattern identical to that seen in invasive breast carcinomas. In 12% of cases no staining for TSP-1 was seen. Two patterns of vascularity were identified. A cuff of vessels immediately adjacent to the basement membrane of ducts with DCIS was seen in 71% of cases. The presence of stromal TSP-1 was significantly associated with DCIS showing no/little necrosis (p = 0.01) and no/little periductal inflammation (p = 0.04). There was a trend between the presence of stromal TSP-1 and tumour cell negativity for p53 (p = 0.087). The stromal microvessel Chalkey point count ranged between 3.33 and 16. An increased stromal microvessel count was associated with high histological grade (p = 0.02), extensive necrosis (p = 0.047), and pronounced periductal inflammation (p = 0.049). There was no association between the presence of stromal TSP-1 and stromal microvessel density.

CONCLUSIONS

TSP-1 is expressed in the stroma around DCIS and in the immediately adjacent basement membrane. Expression of stromal TSP-1 is lost in DCIS with more aggressive histological features. The absence of a relation with microvessel density suggests that other angiogenic factors may play an important role in DCIS.

Dynamic susceptibility contrast MRI of gliomas

Dynamic susceptibility contrast imaging has proven to be useful in brain tumor studies, and it provides additional information on tumor characteristics based on the microvascular structure of gliomas. The cerebral blood volume maps can be used to noninvasively grade gliomas, to determine optimal biopsy sites, to separate radiation necrosis from tumor regrowth, and to plan and follow irradiation, chemo- and antiangiogenic therapy. Besides of cerebral blood volume mapping, dynamic susceptibility contrast imaging sets also contain information about the flow and permeability properties of the tumor microvascular system. When combined with the conventional MRI, dynamic susceptibility contrast techniques offer important functional information about the biology of gliomas in a cost-effective way.

Angiogenesis, thrombospondin, and ductal carcinoma in situ of the breast

Angiogenesis, the growth of new vessels from existing vasculature, plays an essential role in tumour development. The process involves interaction between a variety of cells, growth factors, and components of the extracellular matrix, regulated by pro-angiogenic and anti-angiogenic factors. This review profiles these factors, outlines the available methods for measuring new vessel formation, and discusses the importance of angiogenesis in breast cancer, with emphasis on ductal carcinoma in situ.

Angiogenesis inhibitors in lung cancer

Lung cancer is a major public health problem and the leading cause of cancer-related death worldwide. Its survival rates have changed little over the past 20 years. The best clinical benefit (ie, survival rates) with combination cytotoxic therapies in non-small-cell lung cancer (NSCLC) may have been reached. The need for improved survival rates in NSCLC has driven the development of novel, rationally designed, targeted therapies. Inhibitors of angiogenesis have been developed and are increasingly studied. Potential targets for therapy include inhibitors of vascular endothelial growth factor receptor, endogenous angiogenesis inhibitors, and cyclooxygenase inhibitors. Combining targeted molecules with traditional cytotoxic therapies usually results in lower required chemotherapy doses and fewer, less severe side effects. A number of ongoing randomized studies are underway to evaluate this idea. It is anticipated that these new targeted therapies will play an important role, along with cytotoxic and radiation therapies, in the management of metastatic disease.

[Angiogenesis and bladder cancer: trendy prognostic factor or new therapeutic target?]

Tumor-associated angiogenesis is emerging as an important prognostic factor and represents a hopeful potential therapeutic target for the cancer treatment. Bladder tumors, as all solid tumors, require an active angiogenesis to support their growth and progression. The angiogenic phenotype observed within a tumor is determined in large part by the balance between stimulatory and inhibitory inputs to the endothelial cells. Clinically, the importance of the angiogenic response observed within a tumor should be considered as an independent prognostic factor for superficial as well as invasive bladder tumors. The analysis of the angiogenic response could in the future influence the therapeutic strategy. Angiogenesis also represents a promising new therapeutic target, and is at the moment intensively tested in experimental and clinical trials. In this article, we will first review the mechanism of angiogenesis, and then its implication in bladder cancer, and as a potential therapeutic target.

Angiogenesis in bladder cancer--prognostic marker and target for future therapy

Angiogenesis is the process by which tumours induce a blood supply, crucial for growth and metastasis. Evidence for its role in bladder carcinogenesis, its usefulness as a marker of patient prognosis, and potential anti-angiogenic therapies for future development are discussed in this chapter.

Effects of finasteride and cyproterone acetate on hematuria associated with benign prostatic hyperplasia: a prospective, randomized, controlled study

OBJECTIVES

To evaluate the influence of two differently acting antiandrogens, finasteride (FIN) and cyproterone acetate (CPA), on the natural history of hematuria associated with benign prostatic hyperplasia (BPH) in a prospective, randomized, controlled study.

METHODS

Forty-two patients with hematuria episodes due to BPH were randomly allocated to three subgroups of 14 patients each and treated daily with either 5 mg FIN or 100 mg CPA or were placed in a watchful waiting arm. Patients were evaluated at 3-month intervals, and 40 patients had at least 1 year of follow-up.

RESULTS

Four patients in the FIN group (30%) and three in the CPA group (23%) presented with recurrent hematuria. In both groups, the bleeding episodes were treated conservatively and required no hospitalization. In the control group, 8 patients (57%) presented with recurrent bleeding; in 4, the bleeding was severe and required some form of intervention (catheterization or transurethral prostatectomy). When the frequency and severity of the hematuria episodes were analyzed over time, a statistically significant difference for FIN versus control was present at 9 and 12 months (analysis of variance, P = 0.035 and P = 0.009, respectively). A similar difference was evident for CPA versus control at 9 and 12 months (P = 0.028 and P = 0.008, respectively). No statistically significant difference was present between the FIN and CPA groups. Interestingly, no statistically significant effect in bleeding recurrence for both CPA and FIN over controls was present at 3 and 6 months of follow-up.

CONCLUSIONS

Both FIN and CPA seem to exert a comparable control in hematuria recurrence in patients with BPH, thus confirming the rationale behind the use of antiandrogens for such a purpose. Our results support the hypothesis that any antiandrogen, irrespective of the mode of action, would alter the natural history of BPH-associated hematuria. Interestingly, our results indicate that the speed of action of FIN may not be as rapid as previously described.

Angiogenesis as a biomarker and target in cancer chemoprevention

Angiogenesis, the formation of new blood vessels from existing vasculature, is essential to the late stages of carcinogenesis, allowing tumours to grow beyond 1-2 mm in diameter, invade surrounding tissue, and metastasise. However, more than two decades ago, angiogenesis that preceded neoplastic transformation was seen. Indeed, it can be detected in inflammatory and infectious diseases that increase the risk of developing cancer. Recent advances in fluorescence endoscopy and histological assessment suggest that, for certain cancers, the degree of new blood-vessel formation may differ between the early and late stages of carcinogenic progression. The association between angiogenesis and cancer occurrence, and ease of detection of this process in accessible tissues early in carcinogenesis, mean that angiogenesis fulfils the criteria for a biomarker of the effectiveness of chemopreventive intervention. There is also some evidence that biochemical assays of angiogenic growth factors may offer similar potential as surrogate biomarkers. Many natural and synthetic chemopreventive agents in development or in clinical use inhibit new vessel formation in vivo. Validation of angiogenesis as a biomarker for the effectiveness of chemoprevention should further the advancement of some chemopreventive agents.

A potential role of bradykinin in angiogenesis and growth of S-180 mouse tumors

Angiogenesis is an important event in tumor growth. We evaluated the contribution of endogenous bradykinin to tumor-associated angiogenesis and tumor growth using pharmacological approaches in mice bearing sarcoma 180 cells. The weight of implanted tumors increased in parallel with increased hemoglobin contents (a parameter to evaluate angiogenesis) over a 20-day experimental period. Daily administration of bradykinin B2-receptor antagonists, Hoe140 (0.1 and 1 mg/kg per day, local injection) or FR173657 (30 mg/kg per day, p.o.), significantly suppressed the increment in angiogenesis and tumor weight, but a B1-receptor antagonist, desArg10-Hoe140 (1 mg/kgperday), did not. Administration of a plasma kallikrein inhibitor, soybean trypsin inhibitor (3 mg/site per day), significantly suppressed angiogenesis and tumor growth. In contrast, bradykinin-degrading enzyme inhibitors, captopril and phosphoramidon (500 microg/site per day), enhanced angiogenesis and increased tumor weight. Our results suggest that bradykinin, produced by plasma kallikrein or plasma kallikrein-like enzymes, promote tumor-associated angiogenesis and tumor growth in vivo.

The role of hypoxia and p53 in the regulation of angiogenesis in bladder cancer

PURPOSE

Our previous studies defined thrombospondin-1 (TSP-1) and vascular endothelial growth factor (VEGF) as the primary mediators of angiogenesis in the bladder and the loss of inhibitory TSP-1 as a key event in the transition to an angiogenic phenotype during bladder cancer development. We evaluated the role of p53, which is commonly inactivated in bladder cancer, and hypoxia in the regulation of angiogenesis in the bladder.

MATERIALS AND METHODS

The p53 status was modulated in normal urothelial and bladder cancer cells, and conditioned media was collected under normal oxygen or hypoxic (0.5% O2) conditions. Angiogenic activity was evaluated with the endothelial cell migration assay, and the levels of secreted TSP-1 and VEGF were determined by Western blot analysis and enzyme-linked immunosorbent assay, respectively.

RESULTS

Retroviral mediated expression of the E6 oncoprotein reduced wild-type p53 levels in normal urothelial cells by greater than 90% but did not significantly alter TSP-1 or VEGF levels, while total inductive and inhibitory activities remained unchanged. Adenoviral mediated expression of wild-type p53 was confirmed in 4 bladder cancer cell lines by Western blot analysis for p53 and its downstream effector protein p21 (2.5 to 5.0-fold increase). TSP-1 levels remained unchanged but the levels of secreted VEGF in the high grade UMUC-3 and 253J cell lines were significantly decreased 5 to 50-fold and a corresponding decrease in net angiogenic activity was observed. However, (increased expression) of p53 had no effect on the angiogenic activity of the low grade RT4 or high grade HT1376 bladder cancer cells. Hypoxia converted normal urothelial cell derived conditioned media from anti-angiogenic to angiogenic and increased the angiogenic activity of bladder cancer cell derived conditioned media. This change was due to 2.5 to 6-fold hypoxic up-regulation of VEGF because the expression of inhibitory TSP-1 was not significantly altered.

CONCLUSIONS

Our results suggest that p53 does not regulate angiogenesis in the bladder in the setting of an otherwise normal genome and gene therapy with wild-type p53, which is currently being studied for this cancer, may have only limited effects on angiogenesis. In contrast, hypoxia regulates angiogenesis in this system, primarily through its effects on VEGF.

Tumour angiogenesis and Ki-67 expression in phaeochromocytoma

OBJECTIVE

To determine the expression of CD34 (to evaluate vascularity) and Ki-67 (as a proliferative index) in a variety of phaeochromocytomas and thus assess the utility of these markers as possible predictors of malignancy.

PATIENTS AND METHODS

Deparaffinized tissue sections from 21 patients with benign and four with malignant phaeochromocytoma were assessed immunohistochemically to evaluate microvascular counts (using CD34 antigen) and the proliferative index (Ki-67 antigen, monoclonal antibody MIB-1).

RESULTS

There was no statistical association between high microvascular counts and malignancy, but there was between the MIB-1 score and malignancy (P < 0.001).

CONCLUSIONS

A high MIB-1 score in phaeochromocytoma suggests malignant behaviour in the component cells. The MIB-1 score may be a useful indicator for diagnosing malignant phaeochromocytoma.

Correlation of total VEGF mRNA and protein expression with histologic type, tumor angiogenesis, patient survival and timing of relapse in non-small-cell lung cancer

We have quantified the expression of all 4 isoforms of vascular endothelial growth factor (VEGF) mRNA in non-small-cell lung cancer (NSCLC) using a new kinetic quantitative PCR method, real-time quantitative (RTQ) RT-PCR, and investigated the association between VEGF expression at the mRNA and protein levels and the clinicopathologic variables, tumor angiogenesis, patient survival and timing of relapse. Surgical tumor specimens from 72 NCSLC patients (37 squamous-cell carcinomas, 35 adenocarcinomas) were examined. Twenty-eight patients had stage I, 10 stage II and 34 stage IIIA or IIIB disease. Total VEGF mRNA (all 4 isoforms) was quantified by RTQ RT-PCR, while VEGF protein expression and microvessel number in tumors were assessed immunohistochemically. VEGF mRNA was detected in all 72 tumor samples at significantly higher levels than in adjacent normal tissue. Tumoral VEGF mRNA levels correlated strongly with the VEGF protein staining score and microvessel count. Adenocarcinomas showed significantly higher VEGF mRNA expression and a higher protein staining score than squamous-cell carcinomas. High tumoral VEGF mRNA expression was associated with advanced (IIIA or IIIB) tumor stage, lymph node metastasis, high tumoral microvessel counts, short patient survival (<24 months) and early relapse (<12 months), while a high VEGF protein staining score was associated with high tumoral microvessel counts, short patient survival and early relapse. Patients with high tumoral levels of both VEGF mRNA and protein had significantly shorter survival and earlier relapse. In multivariate analysis, the VEGF protein staining score and nodal status were the most important independent predictors of survival and recurrence. We conclude that RTQ RT-PCR is a sensitive method for detecting and quantifying VEGF mRNA expression in NSCLC and that the expression levels of total VEGF mRNA and protein in NSCLC are strongly associated with histologic type, tumor angiogenesis, survival and timing of relapse. High VEGF expression in adenocarcinomas may contribute to their greater metastatic potential.

Increased cellularity of tumor-encased native vessels in prostate carcinoma is a marker for tumor progression

Changes in the native vasculature of the prostate gland associated with prostate adenocarcinoma have not been well characterized. Eighty-nine whole mounts of entirely submitted radical prostatectomies were reviewed. Thirty prostates with a minimum of five native arteries surrounded by carcinoma with corresponding control arteries were found and included in this study. The number of nuclei in the media of native arteries was recorded per 0.138 mm2 using a 40x objective. The number of nuclei in vessels embedded in carcinoma (n = 204) was increased when compared with controls (26.37 versus 20.58 mean nuclei per 0.138 mm2; P < .001). Pathologic Stage T3 carcinomas contained vessels that were more cellular than stage T2 (P < .001). Vessels embedded in Gleason Grade 4 showed more cellularity than arteries embedded in Gleason Grade 3 (P < .002). Increased media cellularity of native prostate vessels encased in carcinoma is a histologic feature of higher grade/stage prostate carcinoma and provides positive indicator of advanced prostate cancer.

Tumour progression and angiogenesis in bone metastasis from breast cancer: new approaches to an old problem

Breast cancer metastasizes frequently to the skeleton and causes considerable morbidity and deterioration of the quality of life. The clinical consequences of skeletal metastases are bone pain, pathological fractures, hypercalcaemia and nerve compression syndromes. From the moment breast cancer cells are located in the bone microenvironment, they may release factors which stimulate bone resorption and angiogenesis leading to growth of skeletal metastases and a subsequent selective increase in the attraction of new cancer cells to bone. In this review, emerging new concepts of breast cancer-bone interactions, in particular the involvement of angiogenesis, proteolysis and the role of cancer-induced bone resorption in skeletal metastasis are discussed. Better understanding of the processes involved in the metastasis of cancer cells to bone, local tumour growth and subsequent destruction of skeletal architecture can lead to optimal methods for the prevention and treatment of metastatic bone disease.

Automatic quantification of microvessel density in urinary bladder carcinoma

Seventy-three TUR-T biopsies from bladder carcinoma were evaluated regarding microvessel density, defined as microvessel number (nMVD) and cross-section endothelial cell area (aMVD). A semi-automatic and a newly developed, automatic image analysis technique were applied in immunostainings, performed according to an optimized staining protocol. In 12 cases a comparison of biopsy material and the corresponding cystectomy specimen were tested, showing a good correlation in 11 of 12 cases (92%). The techniques proved reproducible for both nMVD and aMVD quantifications related to total tumour area. However, the automatic method was dependent on high immunostaining quality. Simultaneous, semi-automatic quantification of microvessels, stroma and epithelial fraction resulted in a decreased reproducibility. Quantification in ten images, selected in a descending order of MVD by subjective visual judgement, showed a poor observer capacity to estimate and rank MVD. Based on our results we propose quantification of MVD related to one tissue compartment. When staining quality is of high standard, automatic quantification is applicable, which facilitates quantification of multiple areas and thus, should minimize selection variability.

VEGF and VEGF type C play an important role in angiogenesis and lymphangiogenesis in human malignant mesothelioma tumours

The vascular endothelial growth factor (VEGF) family is a novel regulator of endothelial cell proliferation. We assessed the mRNA expression of VEGF, VEGF type C (VEGF-C) and their receptors together with the microvessel density (VD) and microlymphatic vessel density (LVD) in pursuit of their connection and prognostic value in malignant pleural mesothelioma (MPM). We used four human MPM cell lines, 54 MPM tumours and five normal pleural tissues. Expression levels for receptors and ligands were assessed by semiquantitative reverse transcriptase polymerase chain reaction analysis. Microvessels were highlighted by immunohistochemical staining for factor VIII. The discrimination of lymphatics was performed by enzyme-histochemistry for 5'-nucleotidase after adequate inhibition of non-specific activity. The expression levels of VEGF, VEGF-C and VEGFRs were high in all MPM cell lines. The percentages of tumours with higher expression compared to the mean values of normal pleural tissues were 31.5% (17/54) for VEGF, 66.7% (36/54) for VEGF-C, 20.4% (11/54) for fms-like tyrosine kinase (flt)-1, 42.6% (23/54) for kinase insert domain-containing recepter (KDR) and 59.3% (32/54) for flt-4. Significant positive correlations were found between VEGF-C and flt-4, VEGF and KDR, VEGF and flt-1 in tumour tissues. The association between LVD and VEGF-C expression level was especially strong (P< 0.0001, r= 0.63). There were also significant correlations between LVD and flt-4, and VD and VEGF. No correlation, however, was found between LVD and nodal metastasis. VD was a negative prognostic indicator in this study. The associations between VEGFNEGF-C and vessel density suggest that these factors play an important role in angiogenesis and lymphangiogenesis in this tumour, and assessment of vascularity may be a useful prognostic indicator for MPM patients.

Expression of vascular endothelial growth factor and its receptors during lung carcinogenesis by N-nitrosobis(2-hydroxypropyl)amine in rats

The expression of vascular endothelial growth factor (VEGF) and its receptors (VEGFRs), VEGFR-1/Flt-1 and VEGFR-2/Flk-1, was investigated by immunohistochemical and northern blot analysis during lung carcinogenesis by N-nitrosobis(2-hydroxypropyl)amine (BHP) in male Wistar rats. After BHP was given in the drinking water for 12 wk, the rats were maintained without further treatment until they were killed at 20-28 wk. Immunohistochemical studies revealed VEGF expression in almost all malignancies, the reaction being strongly positive in most adenocarcinomas (15 of 18; 83.3%) and squamous cell carcinomas (four of five; 80.0%), but less so in a total of 120 adenomas and 136 alveolar hyperplasias. In addition, VEGF mRNA and VEGFR mRNAs were found to be overexpressed in most adenocarcinomas and squamous cell carcinomas as well as in one to three of the five adenomas tested. The results indicated that VEGF and VEGFRs play important roles in the acquisition of malignant potential by preneoplastic lung lesions induced by BHP in rats. Moreover, overexpression of VEGF was related to upregulation of VEGFR-1/Flt-1 and VEGFR-2/Flk-1 expression in malignant and premalignant lung lesions.

Angiogenesis in malignancies of the female genital tract

OBJECTIVE

The purpose of this work was to review current knowledge pertaining to angiogenesis in malignancies of the female genital tract.

METHODS

We identified studies published in the English language regarding angiogenesis in gynecologic malignancies. The studies were obtained from a MEDLINE search from 1966 through June 1998; additional sources were identified through cross-referencing.

RESULTS

A growing body of evidence confirms the ability of vulvar and cervical squamous cell carcinomas and endometrial and ovarian adenocarcinoma to induce angiogenesis. In vulvar intraepithelial neoplasia a correlation between vascular endothelial growth factor (VEGF) expression, microvessel density (MVD), and progression of dysplasia has been demonstrated. In invasive vulvar carcinoma, high VEGF expression and MVD portend poor prognosis. Currently a debate exists regarding the ability of cervical squamous intraepithelial neoplasia to induce angiogenesis. Most studies, however, indicate angiogenesis to be of prognostic value in patients with invasive squamous cell carcinoma. The ability of complex endometrial hyperplasia to induce angiogenesis has been demonstrated. A direct correlation between angiogenesis, higher grade and depth of invasion in Stage I adenocarcinoma, and prognostic value in Stage I and II and recurrent disease has been noted. In ovarian epithelial adenocarcinoma, higher microvessel counts in the primary ovarian tumor or omental metastases may serve as a prognostic indicator for survival.

CONCLUSIONS

Similar to other malignant diseases, angiogenesis appears to play an important role in disease progression and survival in patients with gynecologic malignancies. Preliminary data indicate angiogenesis may serve as a prognostic indicator in vulvar and cervical squamous cell carcinomas and endometrial and ovarian adenocarcinomas. These findings may lead to future application of therapeutic trials with antiangiogenic factors.

Microautoradiographic quantitation of vascular endothelial growth factor mRNA levels in human prostate specimens containing normal and neoplastic epithelium

Human prostate specimens commonly contain a spectrum of epithelial changes, including normal acinar and ductal structures, hyperplasia, intraepithelial neoplasia (dysplasia), and carcinoma. Since vascular endothelial growth factor (VEGF) expression is dependent on cell type and tissue microenvironment, meaningful quantitation of the levels of this mRNA in pathological specimens requires analysis at the microscopic level. Phosphorimage analysis of the binding of radiolabeled cRNA probes to tissue sections allows quantitation of mRNA levels, but the resolution is limited. Alternatively, emulsion autoradiography allows visualization of mRNA levels at cellular resolution, but quantitation is difficult. We have developed a method of quantitating steady state mRNA levels in tissue sections at the microscopic level, using autoradiography and quantitative image analysis. In this study, we describe the method and apply it to quantitation of VEGF mRNA in human prostate specimens. The VEGF mRNA level was low in nonepithelial stromal tissue (0.8 dpm/mm2), high in normal and benign hyperplastic epithelium (17-18 dpm/mm2), and significantly decreased in intraepithelial neoplasia (6.4 dpm/mm2) and in microacinar carcinoma that had invaded the stroma (3.5 dpm/mm2). Immunohistochemical staining detected VEGF protein in epithelial and stromal cells, with highest levels on the luminal surface of normal epithelium and in stromal cells, and lower levels in benign hyperplasia, intraepithelial neoplasia, and carcinoma. No correlation between VEGF expression in epithelium and nearby vessel density was observed. The results indicate a decrease in the steady state level of VEGF mRNA when prostate epithelial cells become transformed, escape the confines of glandular structure and invade the stroma, and suggest that the progression of prostatic carcinoma through the stages examined in this study is not associated with increased VEGF expression, in contrast to the elevated VEGF expression associated with progression of several other tumor types.

Microvessel density as a prognostic marker for transitional cell carcinoma of the bladder

OBJECTIVE

To investigate the prognostic significance of mean vascular density (MVD) in a variety of transitional cell carcinomas (TCC) obtained by biopsy and cystectomy, and thus determine the importance of vascular density as a prognostic indicator for vesical TCC.

PATIENTS AND METHODS

Tumour vasculature was visualized using factor VIII immunohistochemistry. The MVDs of tumours from 42 cystectomy specimens were correlated with patient survival over a maximum follow-up of 156 months. The results were also compared with those obtained from initial bladder biopsy in a subset of 29 patients.

RESULTS

Twenty-five patients had died over a mean follow-up of 32 months. The MVDs from cystectomy specimens ranged from 29 to 229 vessels per medium-power field (0.94 mm2) while that for biopsies before cystectomy ranged from 51 to 155 vessels. The MVD for both cystectomy and biopsy specimens showed a significant association with survival, but this was absent in a multivariate analysis that included tumour stage and grade, and there was a poor correlation between the MVD of cystectomy- and biopsy-derived tumours.

CONCLUSION

The assessment of tumour vascularity appears to be of little clinical importance for vesical TCC.

Frequent expression of the vascular endothelial growth factor in human non-small-cell lung cancers

BACKGROUND

Angiogenesis is an essential factor for progression and metastases in solid tumors. It has been reported that several angiogenic factors play a role in the regulation of angiogenesis. Vascular endothelial growth factor (VEGF) is one of the most important molecules in angiogenesis. We investigated expressions of VEGF in a series of lung carcinomas with regard to clinicopathological factors.

METHOD

VEGF expression was investigated by use of immunohistochemical studies and Northern blot analysis, using 155 primary and 26 metastatic lung carcinomas for the immunohistochemical studies and 10 primary and two metastatic lung carcinomas for the Northern blot analysis. All lesions were resected at surgery.

RESULTS

The frequencies for positive VEGF expression were 64 of 74 (86.5%) adenocarcinomas, 38 of 67 (56.7%) squamous cell carcinomas, four of four (100%) large cell carcinomas, two of three (66.7%) adenosquamous carcinomas and one of five (20%) small-cell carcinomas, the degree of positivity generally being greater in well differentiated tumors. The majority of metastatic foci from adenocarcinomas and squamous cell carcinomas at other sites were also positive (76.5 and 66.7%, respectively). VEGF expression did not correlate with clinicopathological factors such as tumor size or pathological stage, but pathological stage I adenocarcinoma cases positive for VEGF demonstrated a shorter disease-free period when followed up for 48 months than those cases expressing VEGF negatively.

CONCLUSIONS

The results indicated that VEGF expression was frequently detected in non-small-cell lung cancers and suggested that VEGF might relate to the disease-free period of the patients with early adenocarcinomas.

Advances in angiogenesis research: relevance to urological oncology

PURPOSE

Important advances in angiogenesis research are reviewed along with recent data implicating angiogenesis in the pathogenesis of urological malignancies.

MATERIALS AND METHODS

The current understanding of angiogenesis and its importance in tumor biology is summarized. The rationale for anti-angiogenic therapy is reviewed and the clinical experience with these agents is discussed. An extensive literature search of angiogenesis in urological malignancies was performed.

RESULTS

Quantitative immunohistochemistry for endothelial antigens suggests that, as is the case with many other tumors, induction of angiogenesis contributes to the malignant phenotype of prostate and bladder carcinomas. Anti-angiogenic agents have demonstrated efficacy against urological tumors in experimental systems, and recent data suggest that these agents may also be useful for chemoprophylactic purposes. Putative angiogenesis inducers specific for each of the major urological malignancies have been identified. Quantitation of the expression of angiogenesis inducers and estimation of microvessel density have demonstrated prognostic value for urological malignancies.

CONCLUSIONS

The available data indicate that angiogenesis has an important role in the progression and metastasis of urological malignancies. Preclinical data coupled with experience in other cancers indicate that combining anti-angiogenic therapy with conventional treatment modalities has the potential to improve dramatically our management of these malignancies. Further research will be needed to define the mechanisms controlling angiogenesis in urological malignancies and to determine if any of the angiogenic correlates will be of genuine clinical use. The rapid pace of research in this field suggests that this aspect of tumor biology will soon have an increasingly important role in the evaluation and treatment of urological cancers.

Bladder cancer: natural history, tumor markers, and early detection strategies

Transitional cell bladder carcinoma is characterized by a dichotomous, multichronotopic natural history. Low and moderate grade Ta lesions frequently recur, yet rarely invade, and carry an excellent prognosis with currently available treatments. High grade Ta lesions, tumors with lamina propria invasion (T1), and carcinoma in situ often progress to invasive disease, at which time overall prognosis is significantly decreased, despite various treatment alternatives. Although early detection of bladder tumors, prior to muscle invasion, should vastly improve our ability to save both bladders and lives, current methods of detection are neither sufficiently sensitive nor specific. Tumor marker analysis is an exciting new frontier in bladder cancer evaluation, and may have important applications to early detection strategies, in combination with simple hematuria testing and other selected noninvasive screening methods.

Tumor invasion and angiogenesis in early esophageal squamous cell carcinoma

BACKGROUND AND OBJECTIVES

Although the relationship between angiogenesis and tumor proliferation or malignant potential has been previously demonstrated in several studies, early stage of cancer invasion and angiogenesis has seldom been investigated.

METHODS

From the esophageal specimens of eight recently resected cases with esophageal squamous cell carcinoma, 25 areas of carcinoma-in-situ or microinvasive carcinoma were selected, and then a serial histologic investigation and immunohistochemical staining for the detection of Factor VIII-related antigen to investigate microvessels in the lamina propria mucosae beneath the lesions as a measure of angiogeneses and staining for laminin to visualize basement membrane was performed. Lymphocyte infiltration below the lesions were also estimated. In view of early cancerous invasion, histologic patterns of the growth of the lesions were divided into "flat," "expansive," and "downgrowth" patterns.

RESULTS

Although downgrowth patterns are thought to be more invasive, relationships between the histologic patterns, and basement membrane staining patterns, and lymphocyte infiltration patterns were not demonstrated. However, the angiogenetic ratio (the number of vessels/cm under the lesions divided by that under normal epithelium) was observed to be significantly and closely related to tumor invasion patterns (P < 0.01), although it was not related to the destruction of the basement membrane or lymphocyte infiltration below the lesions.

CONCLUSIONS

The angiogenesis of esophageal squamous cell carcinoma is closely correlated to the tumor invasion patterns in early esophageal cancerous lesions.

Tumor angiogenesis correlates with progression after radical prostatectomy but not with pathologic stage in Gleason sum 5 to 7 adenocarcinoma of the prostate

BACKGROUND

Prior studies have suggested that tumor angiogenesis (microvessel density [MVD]) may be of prognostic significance in patients with prostate carcinoma.

METHODS

The authors examined the relationship of MVD in intermediate grade prostate carcinomas with stage at radical prostatectomy (RP) and progression after RP. For the former group, 109 RP specimens with Gleason sums of 6 and 7 were studied: 34 organ-confined tumors, 37 with capsular penetration, 21 with seminal vesicle involvement, and 17 with pelvic lymph node metastasis. For the latter group, 87 RP specimens were studied that had a Gleason sum of 5 to 7 for which the patients underwent follow-up of at least 7 years or until progression. Thirty-seven patients (43%) progressed at a mean of 3.5 years (range, 1-8 years). Representative sections of each tumor were stained for CD31 and "hot spot" microvessels were quantitated in a 3.14-mm2 area.

RESULTS

In the first arm, there was no relationship between MVD and stage at RP. In the second arm, the mean MVD in tumors that progressed was significantly higher than in nonprogressors (43.0 +/- 26.1 vs. 29.0 +/- 13.1; P < 0.0001 by Wilcoxon-Gehan statistic). MVD and Gleason sum were independent statistically significant predictors of progression (MVD, P < 0.0001; Gleason sum, P < 0.0001 by Cox proportional hazards model).

CONCLUSIONS

MVD is an independent significant predictor of progression after RP for tumors with a Gleason sum of 5 to 7. Because these comprise the majority of RP specimens, it is this group for which discrimination of biologic potential is most needed. Angiogenesis may be useful in the prognostic stratification of patients beyond that possible using stage and grade alone.

Distinct angiogenic patterns are associated with high-grade in situ ductal carcinomas of the breast

Angiogenesis, the formation of new blood vessels from the existing vascular network, has been demonstrated to be an important prognostic factor in invasive breast carcinoma. The switch to an angiogenic phenotype represents a growth-limiting step during carcinogenesis and might, in pre-invasive lesions, indicate the risk for developing an invasive phenotype. The discrepancy between modern therapy options for invasive breast carcinomas and the relatively aggressive treatment of in situ lesions underlines the need for such prognostic factors for ductal in situ breast carcinomas (DCIS). Patterns of vascularity were examined in 75 formalin-fixed, paraffin-embedded DCIS by immunohistochemical staining of vessels using antibodies against Factor VIII-related antigen. Histological classification was performed according to four different systems, based on architectural or cytonuclear features, or a combination of both. Two distinct vascular patterns were observed: a diffuse increase of stromal vascularity between duct lesions (pattern I), which was present alone in 8/75 (11 per cent), and a dense rim of microvessels adjacent to the basement membrane of individual ducts (pattern II), present alone in 12/75 (16 per cent). In total, 57 per cent (43/75) showed pattern 1 and 62 per cent (47/75) showed pattern II. There was a significant correlation between these patterns (P = 0.0001; chi 2 = 15.1), such that both were present in 35 (47 per cent). These different vascular patterns imply two angiogenic pathways: one pathway mediated by angiogenic factors released directly by tumour cells resulting in the rim of vessels and another generated indirectly via recruitment of accessory cells such as macrophage and endothelial cells, which themselves release other angiogenic factors, causing the increase of stromal vascularity. A significant increase in both stromal vascularity (pattern I) and the presence of a rim (pattern II) was observed in high-grade DCIS lesions (P = 0.005 and P = 0.037). Indeed, all the patient relapses occurred in these high-grade lesions, but due to the small number of patient events, no significant correlation of vascular pattern to survival was observed (P > 0.05). This study suggests that distinct patterns of vascularity in DCIS might be useful for identifying patients who are at risk of relapse.

Inhibition of lymph node metastasis by an anti-angiogenic agent, TNP-470

We assessed the inhibitory action of TNP-470 on lymph node metastasis in a metastatic model system using athymic nude mice. Mice were injected subcutaneously with 5 x 10(6) HT-1080 cells in the right groin. TNP-470 (10, 30 and 100 mg kg-1) was injected subcutaneously nine times in total every other day from the 7th day after tumour inoculation. Axillar and inguinal lymph nodes were dissected, and DNA was extracted 5 weeks after tumour inoculation. Specific detection of a human beta-globin-related sequence in metastasized human tumour cells in nude mice was done by the polymerase chain reaction (PCR) technique and analysed by Southern blotting. Anti-tumour effects on primary sites were seen only in the 100 mg kg-1 treatment group. Lymph node metastasis of transplanted HT-1080 cells was seen in all mice of the no treatment group (5/5). On the other hand, incidences of lymph node metastasis in treated mice were 2/4 mice (100 mg kg-1, 2/5 mice (30 mg kg-1) and 4/5 mice (10 mg kg-1). The inhibition ratios of lymph node metastasis were 82.3% at 10 mg kg-1, 97.2% at 30 mg kg-1 and 97.5% at 100 mg kg-1 respectively. This agent may be useful to inhibit lymph node metastasis.

Neoangiogenesis: a putative marker of malignancy in non-small-cell lung cancer (NSCLC) development

Several studies have documented a relevant prognostic role of microvessel count (MC) in non-small-cell lung carcinomas (NSCLC). However, no evidence has been reported about the involvement of neo-angiogenesis in the development of bronchial cancers. The aim of this study was to analyze microvessel density both in normal and in pathological features of the bronchial tree detected concomitantly with carcinomas. In a group of 34 patients resected for NSCLC, 48 bronchial lesions (hyperplasia, squamous metaplasia, moderate dysplasia and in situ carcinoma) were identified. In addition, 20 samples of normal bronchial epithelium from the same patients were analyzed. A monoclonal antibody was used in order to identify microvessels in the most intense areas of neovascularization from the bronchial specimens. MC was also analyzed in invasive components. An increased number of microvessels was observed from normal to dysplastic epithelium, including in situ carcinoma. Mean MC was significantly lower in normal, hyperplastic and squamous metaplastic epithelium than in dysplastic epithelium and in situ carcinoma. In particular, no differences were observed between normal and hyperplastic/metaplastic components, whereas a statistically significant difference appeared between the latter and dysplastic lesions. Moderate dysplasia and in situ carcinoma showed a number of microvessels in the lamina propria of their mucosa which were not significantly different from the invasive component, whereas hyperplastic/metaplastic lesions presented a much lower number of microvessels than invasive cancer. From these data it appears that normal bronchial epithelium and lesions associated with cancers of the bronchial tree show neovascularization in their stromal component. Hyperplasia and squamous metaplasia, unlike dysplasia and in situ carcinoma, show a low microvessel count, and they cannot represent precursor or incipient changes in the bronchial epithelium before the fully developed in situ stage has also been reached.