Novel growth regulatory factors and tumour angiogenesis

Signaling pathways modulated by miRNAs in breast cancer angiogenesis and new therapeutics

MicroRNAs (miRNAs) act as oncogenes or tumor suppressors by suppressing the expression of target genes, some of which are engaged in angiogenic signaling pathways directly or indirectly. Tumor development and metastasis are dependent on angiogenesis, and it is the main reason for the poor prognosis of cancer patients. New blood vessels are formed from pre-existing vessels when angiogenesis occurs. Thus, it is essential to develop primary tumors and the spread of cancer to surrounding tissues. MicroRNAs (miRNAs) are small noncoding RNAs involved in various biological processes. They can bind to the 3'-UTR of their target genes and prevent them from expressing. MiRNAs control the activity of endothelial cells (ECs) through altering many biological pathways, which plays a key role in cancer progression and angiogenesis. Recent findings revealed that tumor-derived extracellular vesicles participated directly in the control of tumor angiogenesis by delivering miRNAs to ECs. miRNAs recently show great promise in cancer therapies to inhibit angiogenesis. In this study, we showed the miRNA-regulated signaling pathways in tumor angiogenesis with highlighting the anti-angiogenic therapy response and miRNA delivery methods that have been used to inhibit angiogenesis in both in vivo and in vitro studies.

A Novel Image Probing System for Precise Quantification of Angiogenesis

The rapid development of clinical diagnostic imaging technology, in tandem with medical and angiogenesis research, has led to some major advances in healthcare. The chorioallantoic membrane assay is commonly used for studying normal angiogenesis as well as putative angiogenic and antiangiogenic substances. Despite the progress, it is generally recognized that a major problem is the lack of a suitable quantitative bioassay for angiogenesis. Image probing is a novel solution to this problem, which, together with its associated discipline of evaluating angiogenesis, is showing great potential not only for accurate measurement of even very small blood vessels but also for detailed three-dimensional quantification of blood vessels and surface characterization. This technique could be a helpful tool for quantification in angiogenesis research.

Changes in Circulating Dendritic Cells and IL-12 in Relation to the Angiogenic Factor VEGF during IL-2 Immunotherapy of Metastatic Renal Cell Cancer

Angiogenesis and immunosuppression are the main biological mechanisms responsible for cancer progression. Moreover, recent observations suggesting a negative influence of angiogenesis on anticancer immunity have shown that some angiogenic factors, such as VEGF, may induce immunosuppression. In addition, the evidence of abnormally high blood levels of VEGF has been proven to be associated with resistance to IL-2 immunotherapy. The present study was performed to establish a possible relation ship between the efficacy of IL-2 cancer immunotherapy and changes in circulating levels of VEGF, IL-12, mature and immature dendritic cells (DC). The study included 25 metastatic renal cell cancer patients who underwent subcutaneus low-dose IL-2 immunotherapy (6 MIU/day for 6 days/week for 4 weeks). Immature and mature DCs were identified as CD123+ and CD11c+ cells, respectively. The clinical response consisted of partial response (PR) in five, stable disease (SD) in 11 and progressive disease (PD) in the remaining nine patients. The mean IL-12 levels observed during IL-2 immunotherapy were significantly higher in patients with PR or SD than in those with PD, whereas the mean VEGF concentrations were significantly higher in patients who had PD than in those with PR or SD. Finally, a significant increase in the mean number of circulating mature DCs occurred only in patients with PR or SD, whereas no significant change was seen in patients with PD. By contrast, no significant change was observed in the mean number of immature DCs. This study shows that the efficacy of IL-2 immunotherapy is associated with a significant increase in circulating mature DCs and IL-12, without any concomitant increase in VEGF concentrations. Further studies will be required to better define the relationship between activation of anticancer immunity and control of angiogenesis-related mechanisms.

Surrogate Markers of Tumoral Angiogenesis

Background

Angiogenesis is a prerequisite for tumor growth and metastasis. Vascular cell adhesion molecule-1 (VCAM-1) is expressed on endothelial cells as a result of vascular endothelial growth factor (VEGF) stimulation.

Purpose

To determine if measurement in serum of VEGF or VCAM-1 provides an accurate measure of tumor angiogenesis.

Methods

VCAM-1 and VEGF were measured in the serum of women with early and advanced breast cancer by ELISA. Levels were compared to levels of VCAM-1 and VEGF in women with normal breasts and levels of the endothelial glycoprotein von Willebrand factor. Levels of VEGF and VCAM-1 in women with early breast cancer were correlated with established clinicopathological prognostic markers and intratumoral microvessel density (IMD).

Results

In early breast cancer serum VCAM-1 correlated closely with the microvessel density in tumors (r=0.61, p<0.001). Women with lymph node-positive and high-grade tumors had higher levels of serum VCAM-1 than women with lymph node-negative and low-grade tumors. Serum VEGF demonstrated no correlation with established prognostic features or IMD. Levels of VCAM-1 and VEGF were raised in women with advanced breast cancer.

Conclusion

Serum VCAM-1 is a surrogate marker of angiogenesis in breast cancer and its measurement may help in the assessment of antiangiogenic drugs currently in phase II trials.

Vascular Endothelial Growth Factor (VEGF) Serum Levels during Cancer Immunotherapy with IL-2: Preliminary Considerations

Neoangiogenesis has been proven to play a fundamental role in promoting cancer spread, and vascular endothelial growth factor (VEGF) is known to represent one of the most important angiogenic factors. The present study was planned to investigate changes in VEGF secretion in cancer patients undergoing immunotherapy with IL-2, with the aim of establishing whether VEGF variations play a role in mediating the IL-2-induced control of neoplastic diseases. The study involved 14 metastatic renal cell cancer patients treated with IL-2 immunotherapy (6 million IU/day subcutaneously for 6 days/week for 4 weeks). The clinical response consisted of partial response (PR) in 3, stable disease (SD) in 6 and progressive disease (PD) in the remaining 5 patients. VEGF serum levels were measured by an enzyme immunoassay designed to determine both bound and unbound VEGF. No significant changes in VEGF mean levels occurred during IL-2 therapy. Moreover, neither in patients with PR or SD nor in those with PD did the mean serum levels of VEGF change significantly in response to IL-2. This preliminary study seems to exclude that changes in the angiogenic factor VEGF may play a role in mediating the therapeutic efficacy of IL-2 cancer immunotherapy. However, since the method of measurement used in our study was designed to detect the total amount of VEGF, it cannot be excluded that changes in the free fraction of the molecule may occur during IL-2 cancer immunotherapy.

Changes in Circulating VEGF Levels in Relation to Clinical Response during Chemotherapy for Metastatic Cancer

Abnormally high blood levels of vascular endothelial growth factor (VEGF) appear to be associated with a poor prognosis in advanced cancer, probably as a consequence of its angiogenic and immunosuppressive effects. The prognostic significance of changes in VEGF secretion during cancer chemotherapy is still unknown. This study aimed to investigate the relation between VEGF variations and therapeutic results during chemotherapy in advanced malignancies. The study included 90 metastatic cancer patients, 59 with non-small cell lung cancer and 31 with colorectal carcinoma. Chemotherapy consisted of cisplatin plus etoposide for NSCLC and camptothecin for colorectal cancer. Abnormally high (>2 SD with respect to values in healthy controls) pretreatment VEGF levels were found in 38/90 (42%) patients. The percentage of non-progressive disease in response to chemotherapy was significantly higher in patients with normal levels of VEGF prior to therapy than in those with elevated pretreatment values of VEGF (10/32 vs 4/27; p<0.05). Moreover, the percentage of VEGF level normalization during chemotherapy was significantly higher in patients with objective tumor response or stable disease than in progressing patients (10/18 vs 0/20; p<0.001). Finally, among patients with tumor response or disease stabilization, the one-year survival rate was significantly higher in patients with chemotherapy-induced normalization of VEGF than in those with persistently high VEGF blood levels (9/10 vs 3/8; p<0.05). These results suggest that changes in VEGF levels during chemotherapy may represent a useful biomarker to predict the effect of chemotherapy in terms of tumor response and survival in patients with metastatic solid neoplasms.

Clinical Significance of Soluble Intercellular Adhesion Molecule-1 and Interleukin-6 in Patients with Extrahepatic Cholangiocarcinoma

Purpose/Aim: Although several prognostic factors for extrahepatic cholangiocarcinoma (EHC) have been reported, preoperative prognostic factors have yet to be established. We investigated the serum concentration of angiogenic, inflammatory, and nutritional parameters.

MATERIALS AND METHODS

Twenty-five patients with EHC were enrolled before starting treatment. Preoperative prognostic factors were identified using multivariate analyses.

RESULTS

The serum soluble intercellular adhesion molecule-1 (sICAM-1) levels were significantly higher in the patients with EHC (436.0 ± 43.2 ng/ml) than in the healthy volunteers (228.6 ± 22.0 ng/ml) (p <.001). In addition, the serum IL-6 levels were significantly higher in the patients (18.0 ± 5.6 pg/ml) than in the healthy volunteers (5.7 ± 0.8 pg/ml) (p <.05). The serum IL-6 and sICAM-1 showed a strong correlation (r = 0.559) in the patients with EHC (p <.01). The serum IL-6 (area under the curve = 0.764, p =.030, cut-off level = 11.6) and sICAM-1 (area under the curve = 0.818, p =.007, cutoff level = 322.6) were revealed to be useful as prognostic factors by the receiver operating characteristic curves. The high IL-6 group and the high sICAM-1 group showed poorer DSS than those of the respective low groups. In the multivariate analysis, IL-6 (hazard ratio: 1.050, 95% confidence interval: 1.002-1.100, p =.043) and sICAM-1 (hazard ratio: 1.009, 95% confidence interval: 1.002-1.015, p =.009) were independent prognostic factors for DSS.

CONCLUSIONS

IL-6 and sICAM-1 were independent preoperative prognostic factors in EHC patients, causing continuous inflammation and malnutrition in collaboration with other pro-angiogenic factors.

Comparative profiling of plasma proteome from breast cancer patients reveals thrombospondin-1 and BRWD3 as serological biomarkers

Breast cancer is the most common cancer in women worldwide. It is necessary to identify biomarkers for early detection, to make accurate prognoses, and to monitor for any recurrence of the cancer. In order to identify potential breast cancer biomarkers, we analyzed the plasma samples of women diagnosed with breast cancer and age-matched normal healthy women by mTRAQ-based stable isotope-labeling mass spectrometry. We identified and quantified 204 proteins including thrombospondin-1 (THBS1) and bromodomain and WD repeat-containing protein 3 (BRWD3) which were increased by more than 5-fold in breast cancer plasma. The plasma levels of the two proteins were evaluated by Western blot assay to confirm for their diagnostic value as serum markers. A 1.8-fold increase in BRWD3 was observed while comparing the plasma levels of breast cancer patients (n = 54) with age-matched normal healthy controls (n = 30), and the area under the receiver operating characteristic curve (AUC) was 0.917. THBS1 was detected in pooled breast cancer plasma at the ratio similar to mTRAQ ratio (> 5-fold). The AUC value for THBS1 was 0.875. The increase of THBS1 was more prominent in estrogen receptor negative and progesterone receptor negative patients than receptor-positive patients. Our results are evidence of the diagnostic value of THBS1 in detecting breast cancer. Based on our findings, we suggest a proteomic method for protein identification and quantification lead to effective biomarker discovery.

Role of bone marrow-derived cells in angiogenesis: focus on macrophages and pericytes

Tumor growth relies on the formation of new blood vessels to receive an adequate supply of oxygen and nutrient. This process is facilitated by both the remodeling of the pre-existing vasculatures and the recruitment of the progenitor/stem cells originated from bone marrow-derived cells (BMDCs). Evidences from both animal studies and human trials have reported that these tumor-associated BMDCs differentiate into a series of stromal cells including macrophages and pericytes, and regulate tumor angiogenesis in various aspects. Macrophages constitute a large portion of the BMDCs infiltrated in the tumor microenvironment, and have been shown to disrupt the balance of pro- and anti-angiogenic signalings by the secretion of various cytokines. Pericytes, mainly derived from the subpopulation of PDGFRβ(+) BMDCs, can provide both pro-survival signaling and mechanical support to maintain the newly formed endothelium via the direct interactions with endothelial cells. In the current review, we summarize the recruitment mechanisms of BMDC-derived macrophages and pericytes within tumor microenvironment, and also review the contribution of these cells to the different aspects of angiogenesis, with particular emphasis on their therapeutic implications as potential targets for anti-tumor strategies.

[Correlation of postoperative serum VEGF levels with platelet counts in non-small cell lung cancer]

背景与目的

已有研究表明:非小细胞肺癌(non-small cell lung cancer, NSCLC)患者手术切除原发肿瘤后其血清中血管内皮生长因子(vascular endothelial growth factor, VEGF)浓度显著升高, 血小板可能是血清中VEGF的主要来源。本研究的目的是探讨NSCLC患者术后血清VEGF浓度的动态变化及其与血小板之间的关系。

方法

应用酶联免疫吸附试验(enzyme linked immunosorbent assay, ELISA)检测法, 监测76例非小细胞肺癌患者术前、术后1天及7天血清VEGF的浓度, 同期检测血小板的浓度。

结果

① NSCLC患者术前、术后1天及7天血清VEGF分别为(842.06±527.24)pg/mL、(1 119.28±609.62)pg/mL、(1 574.09±873.38)pg/mL, 组间比较差异具有统计学意义(P < 0.001);②NSCLC患者术前、术后1天及7天血小板计数分别为(230.42±82.56)×10⁹/L、(196.47±81.48)×10⁹/L、(237.90±86.94)×10⁹/L, 术后1天最低(P < 0.001);③术后7天在血小板高于均数组血清VEGF浓度为(1 842.86±1 006.63)pg/mL, 低于均数组为(1 398.81±734.00)pg/mL, 两组有统计学差异(P=0.043)。

结论

NSCLC患者术后血清VEGF浓度显著升高, 血小板计数高的患者中, 其血清VEGF浓度升高更为明显。

A novel copper chelate modulates tumor associated macrophages to promote anti-tumor response of T cells

BACKGROUND

At the early stages of carcinogenesis, the induction of tumor specific T cell mediated immunity seems to block the tumor growth and give protective anti-tumor immune response. However, tumor associated macrophages (TAMs) might play an immunosuppressive role and subvert this anti tumor immunity leading to tumor progression and metastasis.

METHODOLOGY/PRINCIPAL FINDINGS

The Cu (II) complex, (chelate), copper N-(2-hydroxy acetophenone) glycinate (CuNG), synthesized by us, has previously been shown to have a potential usefulness in immunotherapy of multiple drug resistant cancers. The current study demonstrates that CuNG treatment of TAMs modulates their status from immunosuppressive to proimmunogenic nature. Interestingly, these activated TAMs produced high levels of IL-12 along with low levels of IL-10 that not only allowed strong Th1 response marked by generation of high levels of IFN-gamma but also reduced activation induced T cell death. Similarly, CuNG treatment of peripheral blood monocytes from chemotherapy and/or radiotherapy refractory cancer patients also modulated their cytokine status. Most intriguingly, CuNG treated TAMs could influence reprogramming of TGF-beta producing CD4(+)CD25(+) T cells toward IFN-gamma producing T cells.

CONCLUSION/SIGNIFICANCE

Our results show the potential usefulness of CuNG in immunotherapy of drug-resistant cancers through reprogramming of TAMs that in turn reprogram the T cells and reeducate the T helper function to elicit proper anti-tumorogenic Th1 response leading to effective reduction in tumor growth.

Alkylphospholipids inhibit capillary-like endothelial tube formation in vitro: antiangiogenic properties of a new class of antitumor agents

Synthetic alkylphospholipids (APLs), such as edelfosine, miltefosine and perifosine, constitute a new class of antineoplastic compounds with various clinical applications. Here we have evaluated the antiangiogenic properties of APLs. The sensitivity of three types of vascular endothelial cells (ECs) (bovine aortic ECs, human umbilical vein ECs and human microvascular ECs) to APL-induced apoptosis was dependent on the proliferative status of these cells and correlated with the cellular drug incorporation. Although confluent, nondividing ECs failed to undergo apoptosis, proliferating ECs showed a 3-4-fold higher uptake and significant levels of apoptosis after APL treatment. These findings raised the question of whether APLs interfere with new blood vessel formation. To test the antiangiogenic properties in vitro, we studied the effect of APLs using two different experimental models. The first one tested the ability of human microvascular ECs to invade a three-dimensional human fibrin matrix and form capillary-like tubular networks. In the second model, bovine aortic ECs were grown in a collagen gel sandwich to allow tube formation. We found that all three APLs interfered with endothelial tube formation in a dose-dependent manner, with a more than 50% reduction at 25 micromol/l. Interference with the angiogenic process represents a novel mode of action of APLs and might significantly contribute to the antitumor effect of these compounds.

Expression of inducible nitric oxide synthase and cyclooxygenase-2 in angiogenesis and clinical outcome of human gastric cancer

BACKGROUND AND OBJECTIVES

It has been recognized that inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) produce important endogenous factors of human tumors such as nitric oxide (NO) and prostaglandins, which is involved in the process of carcinogenesis and tumor progression. This study aimed to evaluate the association of clinicopathologic factors, microvessel density, and patient survival with the expression of iNOS and COX-2 in patients with gastric adenocarcinoma.

MATERIALS AND METHODS

Seventy-nine specimens, resected from patients with gastric adenocarcinoma, were investigated by immunohistochemical stain against iNOS and COX-2. Microvessels were stained using anti-CD34 antibody and counted as microvessel density.

RESULTS

Positive iNOS and COX-2 expressions were significantly correlated with microvessel density by multivariate analysis, respectively (P = 0.0127 vs. P = 0.0214). There was significant difference among the four groups (both iNOS and COX-2 positive, iNOS positive only, COX-2 positive only, and both negative) in serosal invasion (P = 0.038), lymph node metastasis (P = 0.038), Helicobacter pylori infection (P = 0.025), vascular invasion (P = 0.035), and microvessel density (P = 0.019). In patients with gastric cancer that co-expressed iNOS and COX-2, prognosis was significantly poorer than in those that expressed either iNOS or COX-2, or did not express both of them (P = 0.01738). The Cox proportional hazard regression analysis indicated that iNOS expression, vascular invasion, serosal invasion, and microvessel density are independent prognostic factors for patients with gastric cancer.

CONCLUSIONS

iNOS and COX-2 expression of gastric cancer are related to tumor angiogenesis, tumor progression, and patient survival in human gastric cancer.

Endostatin gene transfer in murine lung carcinoma cells induces vascular endothelial growth factor secretion resulting in up-regulation of in vivo tumorigenecity

Endostatin (ED) is a carboxyl-terminal fragment of type XVIII collagen with a strong anti-angiogenic activity. The purpose of this study is to determine the effect of ED gene transfer into lung cancer cells on in vivo tumor growth in a murine model. The murine lung cancer cell line, Lewis Lung Carcinoma (LLC), was transfected with ED gene to express and secrete ED. After clones were selected to secrete ED, several stable transfectants with ED gene (LLC/ED) and control transfectants (LLC/Mock) were established. In vitro proliferation of these transfectants demonstrated similar growth speed. In contrast to previous reports, in vivo subcutaneous tumorignecity of LCC/ED transfectants was significantly greater than that of LLC/Mock transfectants. Immunohistochemical staining analysis demonstrated that ED gene transfer induced angiogenesis, suggesting coinduction of another gene implicated for neovascularization. As expected, LLC/ED transfectants secreted not only ED but also vascular endothelial growth factor (VEGF) to a much greater degree than LLC/mock transfectants. Interestingly, culture supernatants of LLC/ED cells enhanced in vitro proliferation of human umbilical vein endothelial cells (HUVEC) to a much greater degree than those of LLC/Mock cells. These results indicate that ED gene transfer in murine lung carcinoma cells induces VEGF secretion, resulting in enhancement of in vivo tumorigenecity in the murine model. More attention should be paid for ED gene therapy into lung cancer cells since it may influence other proteins secretion, which upregulates angiogenesis.

Neoplastic transformation and angiogenesis in the thymus of transgenic mice expressing SV40 T and t antigen under an L-pyruvate kinase promoter (SV12 mice)

Using several techniques, we have assessed morphological characteristics of a malignant thymic tumour in SV12 transgenic (Tg) mice expressing SV40 T and t antigens under control of an L-PK promoter. We describe the development of a carcinoma originating from thymic hyperplasia and followed by the formation of a benign tumour composed chiefly of medullary epithelial cells expressing the transgene and of lymphocytes, a pathology very rarely reported in mice. Our study of the SV12 Tg mice represents the first description of a model of a pure malignant thymic tumour associated with extensive angiogenesis maintained in numerous descendants. The formation of a large tumoral neovascular network, observed here, has never been described in human and/or experimental thymic tumours. Tumoral transformation and angiogenesis are demonstrated by immunolabelling with antibodies against various cytokeratins (CKs) of different molecular weights, vascular endothelial cell markers and VEGF/receptor-2 (Flk-1) present on the neovascular endothelial cells. Different points raised by the originality of this model are discussed. These include the medullary nature of the cells expressing the SV40 transgene and their relationship with the tumoral development. The subset of different molecular weight CK components and their modifications are also considered, as well as the presence of type IV epithelial cells, progenitors of medullary epithelial cells. Finally, the cell signals involved in angiogenesis and the possible action of an angiogenic factor, probably secreted by the tumoral cells themselves, are discussed.

Role of serum vascular endothelial growth factor in the prediction of angiogenesis and prognosis for non-small cell lung cancer

Although vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP)-9 are involved in angiogenesis of various cancers, clinical utility of preoperative serum concentration of these molecules in non-small cell lung cancer (NSCLC) has not yet been elucidated. In this study, we determined the concentration of VEGF, MMP-9 and various other tumor markers in serum prior to surgery and evaluated the results compared with intratumoral vasculature to isolate a valuable marker in determining the prediction of angiogenesis in NSCLC. Among these molecules and serum tumor markers, circulating serum VEGF was identified to markedly correlate with microvessel density (MVD) of the resected tumor specimens. Moreover, overall survival of patients with low VEGF levels (< or =326 ng/ml) was significantly greater than that of patients with high VEGF levels (>326 ng/ml), while patients with low MMP-9 levels (< or =189 ng/ml) and those with high MMP-9 levels (>189 ng/ml) revealed similar overall survival. Conclusively, preoperative concentration of serum VEGF may be the most valuable marker in the prediction of intratumoral angiogenesis and prognosis of patients with NSCLC.

The significance of placenta growth factor in angiogenesis and clinical outcome of human gastric cancer

Placenta growth factor (PlGF) is a member of the vascular endothelial growth factor (VEGF) family of proangiogenic factors and its overexpression has been linked to pathological angiogenesis. We studied the relationship between the expression of PlGF and VEGF in human gastric cancer tissues and microvessel density (MVD), as well as clinical outcome in 79 patients with gastric cancer by using an enzyme immunoassay for PlGF and VEGF expression levels in gastric cancers and surrounding non-cancerous mucosa. PlGF protein levels were significantly higher in tumor than in the corresponding non-tumorous mucosa (median value 48.5 vs 9.8 pg/mg, P < 0.001). In contrast, VEGF protein levels were not (66.7 vs 80.7 pg/mg, P = 0.522). VEGF expression level was not significantly correlated with MVD, patient survival, and clinicopathological factors except Lauren classification in this study. PlGF may be an important angiogenic factor in human gastric cancer, and PlGF expression level was significantly correlated with serosal invasion, positive lymph node metastases, tumor stages, and patient survival.

The significance of thymidine phosphorylase/platelet-derived endothelial cell growth factor activity in renal cell carcinoma

BACKGROUND

Thymidine phosphorylase (TP) is identical to platelet-derived endothelial cell growth factor (PDECGF) and has angiogenic activity. Little is known about the significance of TP/PDECGF activity in patients with renal cell carcinoma (RCC). The authors examined the enzymatic activity of TP in 66 RCC specimens and investigated the association between the level of TP activity and the stage/grade status of patients with RCC. Furthermore, the authors examined the correlation between TP/PDECGF activity and prognosis.

METHODS

TP activity levels in nonfixed, fresh-frozen RCC specimens and in specimens of normal kidney were determined using a thin-layer chromatography assay.

RESULTS

The activity of TP was approximately 3.5-fold greater in RCC specimens compared with normal kidney specimens. TP activity in patients with Stage III-IV RCC was 2.6-fold greater compared with TP activity in patients with Stage I-II RCC. In addition, the level of TP activity was correlated with a higher grade of RCC. Patients who had RCC with low TP activity had a longer postoperative disease-specific survival compared with patients who had RCC with high TP activity in the 5-year follow-up.

CONCLUSIONS

The current study is the first to demonstrate a correlation between levels of TP activity and both disease progression and a higher grade of RCC. It also is the first to show that elevated TP activity in patients with RCC predicts a poor prognosis. The results suggest that high TP/PDECGF activity may be associated with the malignant potential of RCC and that TP/PDECGF may be a molecular therapeutic target in patients with RCC.

Molecular biology of transitional cell carcinoma

Transitional cell carcinoma (TCC) is the fifth most common solid malignancy in the USA. Radical cystectomy will cure a substantial fraction of patients with minimally invasive TCC, but approximately 50% of patients with muscle-invasive or extravesical disease treated by radical cystectomy alone die of metastatic TCC. Transitional cell carcinoma have a diverse collection of biologic and functional characteristics. This is reflected in a differing clinical course. The limited value of established prognosticators, make the analysis of new molecular parameters of interest in predicting the prognosis of bladder cancer patients; in particular, high-risk patient groups that are at risk of progression and recurrence. Over the past decade, there had been major progress in the elucidation of the molecular genetic changes leading to the development of TCC. This review will highlight these important advances and emphasize the ways in which molecular biology is likely to affect the development of future therapies.

Current understanding of the biology of advanced bladder cancer

Transitional cell carcinoma (TCC) is reported to be the fifth most common solid malignancy in the U.S. Although radical cystectomy will cure a substantial number of patients with minimally invasive TCC, many patients with deeply muscle-invasive or extravesical disease who are treated with radical cystectomy alone die of metastatic TCC, as do patients with metastatic disease. The differing clinical course and the limited value of established prognosticators make analysis of new molecular parameters of interest in predicting the prognosis of patients with bladder cancer, particularly those in high-risk groups who are at risk of disease progression and recurrence. In the current review, a comprehensive MEDLINE/PubMed search of articles pertaining to the biology of TCC from 1965 to the present was performed, as well as a bibliographic review of cross references. TCC follow the general concept of multistep carcinogenesis and proceed through two distinct genetic pathways responsible for generating different TCC morphologies, namely the inactivation of cyclin-dependent kinase inhibitors in low-grade TCC and early p53-mediated abnormalities in high-grade TCC. TCC progression correlates with genetic instability and the accumulation of collaborative genetic lesions mainly involving p53, retinoblastoma, and growth factors. The bulk of these data are derived from cases of localized/locally advanced disease and none are ready yet for routine clinical application; however, the current knowledge has led to the clinical testing of novel biologic observations in several important trials. Understanding of the molecular biology of advanced bladder cancer continues to improve. It is likely that in the new millennium, real breakthroughs in the identification and therapy of high-risk, poor-prognosis patients will come from an integration of molecular modalities in the clinical application.

Prognostic importance of tumor angiogenesis in breast carcinoma with adjuvant chemotherapy

Tumor angiogenesis is believed to be related to prognostic factors involved in tumor development and metastasis. Using immunohistochemical methods, we evaluated tumor angiogenesis in 42 early invasive breast cancer patients (T1-2, NO-1-2, M0). Four patients received tamoxifen, 25 patients received CAF or CA, and 15 patients received CMF as adjuvant therapy. The median follow-up was 47 (range 24-119) months. Ten patients (43.5%) in the node-positive group and 2 patients (10.5%) in the node-negative group relapsed (p = 0.019). The mean microvessel count (MVC) was 60.3 3.05 per 200x field (range: 16-95). MVCs of postmenopausal and premenopausal patients were 50.13 +/- 5.74 and 68.64 +/- 4.11, respectively, in the axillary lymph node (ALN)-negative patient group (p = 0.04). Staining was moderate to strong in 13 (68%) ALN-negative and in 17 (74%) ALN-positive patients (p > 0.05), and was also moderate to strong in 82% of premenopausal patients and in 50% of postmenopausal patients (p = 0.037). There was no significant relationship between angiogenesis and p53, nor was angiogenesis significantly associated with the patient ER status and tumor size. No significant correlations were found between OS/DFS and Factor VIII staining or p53 (log rank test, p > 0.05). Of all ALN-negative patients with increased angiogenesis, one patient of the CMF group relapsed, but no recurrence occurred in patients undergoing anthracycline-based chemotherapy (p > 0.05). On the other hand, of all ALN-positive patients with increased angiogenesis, 5/14 patients treated with anthracylcine and 2/2 CMF-treated patients relapsed (p = 0.175). Despite the statistical insignificance, anthracycline-based adjuvant chemotherapy appears to be more effective than CMF as regards relapse prevention particularly in early ALN-positive breast cancer patients with increased angiogenesis. Additional studies are necessary to demonstrate the clinical importance of angiogenesis.

Putative role of 67 kDa elastin-laminin receptor in tumor invasion

Cellular regulatory mechanisms normally maintain a delicate balance between cell proliferation, quiescence and death. The imbalance between these functions resulting from molecular intracellular changes is a key factor in tumorigenesis. Tumor cells detaching from the primary tumor possess a propension for invasion and metastasis formation. These tumor cells can attach, migrate, proliferate and grow in host tissue. The surrounding extracellular matrix (ECM) modulates these functions. It is now widely accepted that cell-matrix interactions play an important role in these processes. Most investigators concentrated their attention on the role of integrins in the above processes. There are, however, only scant data on the role of elastin and its receptors in tumor invasion. Nevertheless, experimental evidence indicates that the 67 kDa elastin-laminin receptor (ELR) subunit plays an important role in tumor invasion by mediating essential tumor cell functions leading to metastases. In this review we will concentrate on the putative role of the 67 kDa ELR subunit in tumor invasion.

Association of color Doppler vascularity index and microvessel density with survival in patients with gastric cancer

OBJECTIVE

The purpose of this study was to investigate the clinical usefulness of microvessel density (MVD) and an in vivo angiogenesis parameter, color Doppler vascularity index (CDVI), in patients with gastric cancer.

SUMMARY BACKGROUND DATA

Many studies have reported a significant association between the degree of MVD-evaluated angiogenesis with the clinicopathologic factors and prognosis of patients with various solid tumors. All these studies were accomplished on tissue sections retrospectively obtained from surgical specimens. However, an in vivo method to assess tumor angiogenesis for human malignancies is highly desirable for diagnostic purpose, treatment planning, and follow-up. The CDVI is a new ultrasound parameter for evaluating in vivo angiogenesis, has a good correlation with status of lymph node metastasis in cervical carcinoma, and can predict distant metastasis and survival in colon cancer patients. Therefore, the CDVI may also be useful to assess in vivo angiogenesis in human gastric cancer.

METHODS

A total of 79 patients with gastric cancer were enrolled in this study, and microvessel density was evaluated by using immunohistochemical staining of surgical specimens with anti-CD-34 antibody. Tumors were sonographically visible in 31 patients. The CDVI of each tumor was determined using transabdominal color Doppler ultrasound. The CDVI was defined as the ratio of the number of the colored pixels within a tumor section to the number of total pixels in that specific tumor section, and was calculated by using Encomate software (Electronic Business Machine Co. Ltd., Taipei, Taiwan). Correlation between MVD, CDVI and clinicopathologic factors and patient survival was studied.

RESULTS

The MVD was significantly correlated with vascular invasion by multiple linear regression analysis. Although the survival of patients with high MVD (> 32) was significantly worse than those with low MVD (< 32) by univariate analysis, vascular invasion was an independent prognostic factor by Cox proportional hazard model. There was a linear correlation between CDVI and MVD (r =.495, P =.005). Moreover, in patients with a high CDVI (> 11%), the survival rate was significantly lower than that in those with low CDVI (< or = 11%, P =.005). None of the patients with high CDVI (> 11%) survived 2 years after curative resection. In addition to vascular invasion, the CDVI was another independent prognostic factor in the patients with stage III gastric cancer.

CONCLUSIONS

Vascular invasion was an important prognostic indicator in gastric cancer. The high CDVI was a good preoperative indicator of early death in stage III gastric cancer patients. Thus, the CDVI may be helpful in selecting patients with gastric cancer for neoadjuvant chemotherapy and/or anti-angiogenic therapy.

A high vascular count and overexpression of vascular endothelial growth factor are associated with unfavourable prognosis in operated small cell lung carcinoma

It has been widely demonstrated that neo-angiogenesis and its mediators (i.e. vascular endothelial growth factor), represent useful indicators of poor prognosis in non small cell lung carcinoma. In order to verify whether neovascularization and vascular endothelial growth factor may be considered useful markers of clinical outcome also in the small cell lung cancer subgroup, we retrospectively investigated a series of 75 patients with small cell lung carcinoma treated by surgery between 1980 and 1990. Immunohistochemically-detected microvessels and vascular endothelial growth factor expressing cells were significantly associated with poor prognosis, as well as with nodal status and pathological stage. In fact, patients whose tumours had vascular count and vascular endothelial growth factor expression higher than median value of the entire series (59 vessels per 0.74 mm(2) and 50% of positive cells, respectively), showed a shorter overall and disease-free survival (P=0.001, P=0.001; P=0.008, P=0.03). Moreover, the presence of hilar and/or mediastinal nodal metastasis and advanced stage significantly affected overall and disease-free interval (P=0.00009, P=0.00001; P=0.0001, P=0.00001). At multivariate analysis, only vascular endothelial growth factor expression retained its influence on overall survival (P=0.001), suggesting that angiogenic phenomenon may have an important role in the clinical behaviour of this lung cancer subgroup.

Plasma fibrin D-dimer levels correlate with tumour volume, progression rate and survival in patients with metastatic breast cancer

Plasma levels of D-dimer are elevated in cancer patients. Activation of the extrinsic coagulation system and the fibrinolytic cascade within a tumour is thought to be related with growth, invasion and metastasis. We have investigated the relationship between these markers of fibrin metabolism, standard clinicopathological variables and serum levels of angiogenic cytokines in three cohorts: group A (n=30) consisted of 30 healthy female volunteers, group B (n=23) of consecutive patients with operable breast cancer and group C (n=84) of patients with untreated or progressive metastatic breast cancer. Plasma D-dimers, fibrinogen, IL-6, vascular endothelial growth factor and calculated vascular endothelial growth factor load in platelets are clearly increased in patients with breast cancer. D-dimers were increased in nearly 89% of patients with progressive metastatic disease. The level of D-dimers was positively correlated with tumour load (P<0.0001), number of metastatic sites (P=0.002), progression kinetics (P<0.0001) and the cytokines related to angiogenesis: serum vascular endothelial growth factor (P=0.0016, Spearman correlation=0.285), calculated vascular endothelial growth factor load in platelets (P<0.0001, Spearman correlation=0.37) and serum interleukin-6 (P<0.0001, Spearman correlation=0.59). Similarly increased D-dimer levels were positively correlated with increased fibrinogen levels (P<0.0001, Spearman correlation=0.38). The association between markers of fibrin degradation in patients with progressive breast cancer suggests that the D-dimer level is a clinically important marker for progression and points towards a relation between haemostasis and tumour progression. A role of interleukin-6, by influencing both angiogenesis and haemostasis, is suggested by these observations.

High vascularity in the peripheral region of non-small cell lung cancer tissue is associated with tumor progression

OBJECTIVES

We attempted to determine if the degree of angiogenesis can serve as a prognostic factor in the case of completely resected non-small cell lung cancer patients, with special reference to the center and the periphery of the tumor tissue.

METHOD

For 255 Japanese patients who underwent completely resected non-small cell lung cancer (NSCLC), micro vessel density (MVD) was assessed by visual quantification of microvessels immunostained with anti-CD34 monoclonal antibody in 5 m section. Vascular endothelial growth factor (VEGF) was also immunostained on the same paraffin block specimen.

RESULTS

MVD at the center (MVD-c) and that at the periphery (MVD-p) were frequently different in each individual although a weak positive correlation was observed (r=0.499, P<0.0001). One hundred and one patients with high MVD-p, but not the 107 patients with high MVD-c, showed a significantly higher proportion of advanced stage, larger tumor size and nodal metastasis as compared with MVD. The 5 year survival rate and median survival time for the high MVD-p group were significantly lower than that of low the MVD-p group (43.0%/31 months vs 48.6%/54 months, P=0.0256). As to the relationship among vascular endothelial growth factor (VEGF) and MVD, expression of VEGF was not associated with the degree of MVD. However, patients with high grade MVD-p showed an unfavorable prognosis in cases of high expression of VEGF.

CONCLUSION

High MVD-p is associated with advancement of NSCLC, and it was particularly apparent in conjunction with high VEGF expression.

A 5-year follow-up study for distance visual acuity after low dose radiation on subfoveal choroidal neovascularization in age-related macular degeneration

In a prospective study with a 5-year follow-up, we assessed the effect of a single series of low-dose radiation on the distance visual acuity in eyes with angiographically confirmed subfoveal choroidal neovascularization (CNV) in age-related macular degeneration (ARMD). The posterior pole of 12 eyes was treated with 5 Gy (4 x 1.25 Gy), and 34 eyes treated with 8 Gy (4 x 2 Gy). The best corrected distance visual acuity was measured at the time of treatment, and annually thereafter for 5 years. The study obtained complete follow-up for 11 patients in the 5-Gy group (nine classic, two occult CNVs), and 29 patients in the 8-Gy group (12 classic, 17 occult CNVs). At baseline, the mean distance visual acuity of the treated eyes was 0.16 (20/125) in the 5-Gy group, and 0.2 (20/100) in the 8-Gy group. Five years later, an average loss of 3.2 lines was present in the 5-Gy group, and 4 lines in the 8-Gy group. After 5 years, an average loss of 2 lines was found in a control group consisting of 18 second eyes with low stage dry ARMD, with a mean distance visual acuity of 0.5 (20/40) at baseline. Statistical analyses with Wilcoxon and Mann-Whitney U-tests showed that a single series of low dose radiation with either 5 Gy or 8 Gy was not able to stabilize the distance visual acuity of eyes with subfoveal CNV in ARMD during a 5-year follow-up.

Expression of vascular endothelial growth factor and its role in oncogenesis of human gastric carcinoma

AIM

To establish the role of vascular endothelial growth factor (VEGF) in the oncogenesis of human gastric carcinoma more directly.

METHODS

The expression of VEGF and its receptor kinase-domain insert containing receptor (KDR) in human gastric cancer tissue were observed by immunohistochemical staining. VEGF levels were manipulated in human gastric cancer cell using eukaryotic expression constructs designed to express the complete VEGF(165) complimentary DNA in either the sense or antisense orientation. The biological changes of the cells were observed in which VEGF was up-regulated or down-regulated.

RESULTS

VEGF-positive rate was 50%, and VEGF was mainly localized in the cytoplasm and membrane of the tumor cells, while KDR was mainly located in the membrane of vascular endothelial cells in gastric cancer tissues and peri-cancerous tissue. In 2 cases of 50 specimens, the gastric cancer cells expressed KDR, localized in both the cytoplasm and membrane. Introduction of VEGF(165) antisense into human gastric cancer cells (SGC-7901, immunofluorescence intensity, 31.6%)) resulted in a significant reduction in VEGF-specific messenger RNA and total and cell surface VEGF protein (immunofluorescence intensity, 8.9%) (P<0.05). Conversely, stable integration of VEGF(165) in the sense orientation resulted in an increase in cellular and cell surface VEGF (immunofluorescence intensity, 75.4%) (P<0.05). Lowered VEGF levels were associated with a marked decrease in the growth of nude mouse xenografted tumor (at 33 days postimplantation, tumor volume: 345.40 +/- 136.31 mm3)(P<0.05 vs control SGC-7901 group: 1534.40 +/- 362.88 mm3), whereas up-regulation of VEGF resulted in increased xenografted tumor size (at 33 days postimplantation, tumor volume: 2350.50 +/- 637.70 mm3) (P<0.05 vs control SGC-7901 group).

CONCLUSION

This study provides direct evidence that VEGF plays an important role in the oncogenesis of human gastric cancer.

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.

Angiogenesis in head and neck squamous cell carcinoma

Tumour angiogenesis has recently attracted a great deal of attention as a critical part of oncogenesis and a necessary prerequisite for a malignant phenotype. Research into this process not only offers new insights into tumour biology but is also leading to the development of realistic novel and minimally toxic anti-tumour therapies. Various pro-angiogenic and anti-angiogenic cytokines and pathways have been characterized and their interrelationships are becoming increasingly complex as new findings are made. This article reviews the current understanding of tumour angiogenesis, the basic mechanisms involved and the more important and investigated pathways and proteins involved.

Concentration of vascular endothelial growth factor (VEGF) and transforming growth factor-beta1 (TGF-beta1) in the serum of patients with cervical cancer: prediction of response

The aim of this study was to determine the value of the measurement of serum VEGF and TGF-beta1 levels in the diagnosis of cervical cancer and to see whether these levels decrease after treatment for cervical cancer. We measured serum VEGF and TGF-beta1 levels through EIA in patients with CIN (n = 35), and cervical squamous cell cancer (n = 48). We also measured serum VEGF, TGF-beta1, and SCC antigen levels before and after radiotherapy in 13 cervical squamous cell cancer patients. The sizes of the tumors in those patients were measured by a computer tomography scan or magnetic resonance imaging. The serum VEGF levels were different between CIN and cervical cancer groups (P < 0.1), and the serum TGF-beta 1 levels in the cervical cancer group were lower than those in the other groups (P < 0.05). The serum VEGF levels were significantly related to the serum TGF-beta 1 levels in the cervical cancer patients (P < 0.01). In the cervical cancer patients, the decrease in the circulating VEGF levels after receiving radiotherapy was related to the decrease in tumor size (P < 0.01). While the measurement of serum VEGF level is adjuvant in diagnosing cervical cancers, serial serum VEGF level measurements may find a clinical use in the follow-up of women treated for cervical cancer.

Expression of platelet-derived endothelial cell growth factor/thymidine phosphorylase in human gallbladder lesions

The aim of this study was to investigate the expression of platelet-derived endothelial growth factor (PD-ECGF) in human gallbladder carcinomas to elucidate its role in angiogenesis and tumour progression. To this end, 56 archival surgical specimens of gallbladder lesions were examined for PD-ECGF/thymidine phosphorylase (TP) expression by immunohistochemistry and the PD-ECGF/TP protein level was assessed in five fresh specimens of gallbladder carcinoma by enzyme-linked immunosorbent assay (ELISA). Hyperplastic epithelial cells and adenoma cells showed no or faint staining with PD-ECGF/TP. Out of 43 gallbladder carcinomas, 27 (63%) showed moderate to strong immunoreactivity in the cytoplasm and nuclei of the tumour cells. PD-ECGF/TP immunoreactivity in stromal infiltrating cells was detected in 43% (3/7) hyperplasias, 17% (1/6) adenomas and 86% (37/43) carcinomas. PD-ECGF/TP protein levels in carcinoma tissues were higher than those in corresponding normal mucosa. PD-ECGF/TP expression did not correlate with angiogenesis, but significantly correlated with depth of invasion, lymph node metastasis, and tumour stage. These results overall suggest that PD-ECGF/TP produced by both cancer cells and infiltrating cells is associated with tumour progression in human gallbladder carcinoma.

Microvessel count, proliferating cell nuclear antigen and Ki-67 indices in gastric adenocarcinoma

The aim of the present study was to immunohistochemically investigate the prognostic value of neovascularization (expressed as microvessel count-MVC) and tumor cell proliferation (expressed as PCNA labeling index PLI and Ki-67 labeling index KLI) in gastric adenocarcinoma. Correlations with clinicopathologic features were also evaluated. Tumor specimens from 74 patients diagnosed as gastric adenocarcinoma were included in this study. Formalin fixed, paraffin embedded tissue sections stained immunohistochemically with F-VIII, PC10 and MIB-1 monoclonal antibodies. By ocular grid subdivided into 100 areas, number of microvessels and PC10, MIB-1 positive and negative cells were counted at x400 magnification. Chi-square test, Kaplan-Meier method and cox regression analysis were used for statistical analysis. The results showed that, MVC and PLI had a significant correlation with invasion and lymph node metastasis. The prognosis was significantly worse in patients with high MVC (>14 ) and with high PLI (>49%). However any relationship was not observed between KLI (38%) and clinicopathologic parameters, so KLI failed to predict the prognosis. Cox model showed that, MVC and PLI were independent prognostic variables. Ki-67 labeling index in gastric carcinomas has no prognostic relevance. However, the evaluation of microvessel count and proliferating cell nuclear antigen index in gastric carcinomas could be reliable indicators of prognosis.

Ophthalmic plaque radiotherapy for age-related macular degeneration associated with subretinal neovascularization

PURPOSE

To evaluate ophthalmic plaque radiotherapy for the treatment of subretinal neovascularization associated with age-related macular degeneration.

METHODS

In a prospective phase I clinical trial, we treated 23 patients (23 eyes) with ophthalmic plaque radiotherapy for subfoveal exudative macular degeneration. Palladium 103 ophthalmic plaque brachytherapy was delivered to a retinal apex dose of 1,250 to 2,362 cGy (rad). Early Treatment Diabetic Retinopathy Study type visual acuity determinations, ophthalmic examinations, and angiography were performed before and after treatment. Clinical evaluations were performed in a nonrandomized and unmasked fashion.

RESULTS

Patients were followed up for a mean (+/-SD) of 19 +/- 10.7 months (range, 3 to 37 months). Six months after radiation therapy, three (16%) of 19 eyes had lost 3 or more lines of best-corrected visual acuity; 12 months after radiation therapy, four eyes (31% of 13 eyes), and 24 months after radiation therapy, only two (22% of nine eyes) lost 3 or more lines of visual acuity. No eye suffered sudden irreversible loss of central vision. No radiation retinopathy, optic neuropathy, or cataract could be attributed to radiotherapy within this follow-up period.

CONCLUSION

Ophthalmic plaque radiotherapy can be used to treat neovascular age-related macular degeneration. In contrast to external beam radiotherapy, ophthalmic plaque radiotherapy is a unilateral treatment, which allows a larger dose to be delivered to the macula with less irradiation of normal ocular structures. We have found no sight-limiting complications at the doses, dose rates, and follow-up evaluated in this study.

Quantitative assessment of angiogenesis in the chick embryo and its chorioallantoic membrane by computerised analysis of angiographic images

We studied, in vivo, the angiogenesis process in the chick embryo and its chorioallantoic membrane (CAM) using digital subtraction angiography (DSA) in conjunction with computer-assisted image analysis. In a series of fertilised eggs, angiography was carried out at days 8, 10, 12 and 14 of embryonic development. The angiographic images were digitised and subsequently processed for a specific image analysis. A set of specific morphological parameters has been defined to allow an analytical characterisation of the vascularity status. Vessels were classified into three categories according to their diameter (50-100, 100-200, and > 200 microm). The data were normalised and statistically evaluated. Graphs showing the development of angiogenesis were obtained. Total vascular area revealed a continuous rise, whereas, total vascular length increased until day 12 and then it started decreasing. These morphometric parameters in the first two vessel categories progressively increased throughout the entire period of development, whereas in the third category they increased until day 10 and then they started decreasing. By applying a vascular casting technique CAM vessels were visualised and compared with those extracted from the processed angiographic image. The comparison revealed that there is exact matching for the first two vessel categories (diameters higher than 100 microm) while the matching of the third category (diameters between 50 and 100 microm) is approximate.

The expression of thymidine phosphorylase/platelet-derived endothelial cell growth factor is correlated to angiogenesis in breast cancer

It has been shown that human thymidine phosphorylase (TP) is identical to platelet-derived endothelial cell growth factor and has angiogenic activity. In the present study, the expression of TP was examined in 139 mammary carcinomas and 35 benign mammary disorders using biochemical and immunohistochemical methods. Moreover, in order to evaluate the significance of TP expression in mammary carcinomas, the relationship between vascular density and various clinicopathological factors, including age and menopausal status of patients with a mammary carcinoma, were compared with the size, nodal status, expression of estrogen receptor (ER), progesterone receptor (PgR), c-erbB-2, p53 and TP of a mammary carcinoma. Thymidine phosphorylase expression increased in both the nuclei and cytoplasm of mammary carcinoma cells in comparison to mammary benign disorder cells. The number of microvessels in mammary carcinomas was generally correlated to the number of tumor cells with TP expression in cytoplasm. The number of cells with TP expression in cytoplasm was significantly large in tumors that measured 3-4 cm in diameter, compared with tumors measuring 1-2 and 5-6 cm in diameter. In mammary tumors of 1-4 cm diameter, TP expression and vessel density were significantly high in tumors negative for ER or positive for c-erbB2 and in tumors positive for TP or c-erbB2, respectively; whereas tumors of 5-6 cm in diameter were not modified by any clinicopathological factors. The results indicated that TP plays an important angiogenetic role in mammary carcinomas, especially tumors with a certain progression.

The expression and localization of fibroblast growth factor-1 (FGF-1) and FGF receptor-1 (FGFR-1) in human breast cancer

Fibroblast growth factor-1 (FGF-1) is an inducer of angiogenesis, the growth of new blood vessels. The expression and localization of FGF-1 (acidic FGF) and FGF receptor (FGFR)-1 in mammary tissues from patients with breast cancer was investigated using Western blot analysis and immunohistochemistry. The affinity-purified FGF-1 antibody which did not have cross-reactivity to FGF-2 (basic FGF) was used in this study. Western blot analysis demonstrated the presence of FGF-1 protein in all of the samples from breast cancer, but not benign tumors such as mastopathy and fibroadenoma. To assess the localization of FGF-1 in cancer tissues, immunostaining with specific antibody was performed. All samples from breast cancer displayed significantly intense staining with FGF-1 antibody. The extent and intensity of immunoreactive FGF-1 polypeptides in cancer cells was statistically much greater than those of cells from fibroadenoma or mastopathy. Control immunostaining with normal rabbit serum or anti-FGF-1 antibody adsorbed with the recombinant FGF-1 polypeptide was completely negative. In contrast to FGF-1, Western blot analysis demonstrated the presence of FGFR-1 protein in all of the samples from breast cancer and benign tumors. By immunohistochemical analysis, the enhanced expression of FGFR-1 was observed in breast cancer cells. Benign tumor cells or interstitial cells displayed a faint expression of FGFR-1. These results demonstrated that breast cancer cells not only generated FGF-1, but also expressed FGFR-1, and FGF-1 might play a role in the proliferation of breast cancer cells not only by paracrine but also by autocrine mechanism.

Thymidine phosphorylase (platelet-derived endothelial cell growth factor), microvessel density and clinical outcome in hepatocellular carcinoma

BACKGROUND/AIMS

Angiogenesis plays an important role in tumor growth and metastasis. It is regulated by angiogenic factors. Thymidine phosphorylase (platelet-derived endothelial cell growth factor) is one such factor. Although the significance of platelet-derived endothelial cell growth factor has been studied for several types of tumor, the expression of platelet-derived endothelial cell growth factor and its correlation with microvessel density or clinicopathological factors in hepatocellular carcinoma are unknown. We evaluated microvessel density and platelet-derived endothelial cell growth factor expression in hepatocellular carcinoma to determine whether microvessel density and platelet-derived endothelial cell growth factor expression are correlated with the clinicopathological factors of hepatocellular carcinoma.

METHODS

Using immunohistochemical staining with anti-platelet-derived endothelial cell growth factor antibody and the ELISA method, we evaluated the correlation among platelet-derived endothelial cell growth factor expression, microvessel density and clinicopathological factors in 84 hepatocellular carcinoma patients. Microvessels were stained with anti-human von Willebrand factor (anti-Factor VIII) and anti-CD34.

RESULTS

In the surrounding liver, there was a significant correlation between microvessel density and platelet-derived endothelial cell growth factor expression (p=0.002), and hepatitis C virus-positive livers had higher microvessel densities than otherwise (p=0.003). However, this correlation was not found for hepatocellular carcinoma, but hepatitis C virus-positive tumors had higher expression of platelet-derived endothelial cell growth factor (p=0.018). Microvessel density in hepatocellular carcinoma obtained by Factor VIII staining inversely affected the recurrence-free survival rate (p=0.0416), but the microvessel density by CD34 staining was not a significant predictor.

CONCLUSIONS

This study indicates that platelet-derived endothelial cell growth factor may not be a major regulator of angiogenesis of hepatocellular carcinoma, but this enzyme may play an important role in hepatocarcinogenesis cooperating with hepatitis C virus. Also, the density, not of sinusoid-like vessels, but of larger vessels in hepatocellular carcinoma could be a prognostic factor for hepatocellular carcinoma.

Differential expression of vascular endothelial growth factor mRNA vs protein isoform expression in human breast cancer and relationship to eIF-4E

Angiogenesis is the formation of new blood vessels from the existing vasculature. Vascular endothelial growth factor (VEGF) is an endothelium-specific angiogenic factor strongly implicated in pathological angiogenesis. In this study, the mRNA and protein expression of the four alternatively spliced VEGF isoforms (121, 165, 189 and 206 amino acids) were examined in normal and malignant breast tissues. Three VEGF transcripts were detected in both (121>165>189), whereas only VEGF165 protein was detected. The tumours expressed more VEGF mRNA (P = 0.02) and protein (P < 0.0001), with eight-fold more VEGF protein generated per mRNA unit (P = 0.009). To examine this further, the expression of eIF-4E, a translation initiation factor, was examined. Increased eIF-4E mRNA levels were detected in the tumours (P < 0.0001) that correlated with VEGF mRNA (P = 0.0002), implying co-regulation of these genes. VEGF mRNA expression was elevated in tumours expressing the epidermal growth factor receptor (P < 0.01), but there was no difference according to oestrogen receptor status (P = 0.9), node status (P = 0.09) or between differing histologies (P = 0.4). These data suggest that elevated VEGF protein expression, by both enhanced transcription and translation, is a potential means by which tumour angiogenesis is induced in breast carcinomas. VEGF expression is also significantly associated with factors correlating with a poor outcome, implying a role in progression of this disease.

Vascular endothelial growth factor expression in non-small-cell lung cancer: prognostic significance in squamous cell carcinoma

BACKGROUND

Recently, some studies have focused on the tumor angiogenesis and its prognostic value. We studied the expression of vascular endothelial growth factor, microvessel counts, and serum concentrations of vascular endothelial growth factor to investigate their association with clinicopathologic factors and prognosis in non-small-cell lung cancer.

METHODS

The expression of vascular endothelial growth factor was determined by an immunohistochemical analysis from 91 paraffin specimens of completely resected non-small-cell lung cancers using anti-growth factor polyclonal antibody. Microvessel staining was performed by immunohistochemical analysis with anti-factor VIII-related antigen polyclonal antibody. Measurement of the serum concentrations of vascular endothelial growth factor used the sandwich enzyme-linked immunosorbent assay technique.

RESULTS

Expression of vascular endothelial growth factor was detected in 48 of the 91 tumors. The positive ratio was significantly higher in patients with adenocarcinoma than in those with squamous cell carcinoma. The microvessel counts were significantly higher in the patients with nodal metastasis than in those without nodal metastasis. The serum concentrations of vascular endothelial growth factor were also significantly higher in the patients with T3-4 disease than in those with T1-2 disease. The microvessel counts were closely associated with expression of vascular endothelial growth factor. The prognosis of patients with a positive growth factor ratio was significantly worse than that of the patients with a negative ratio (p = 0.002), especially in squamous cell carcinoma. According to a multivariate analysis, only nodal status and expression of vascular endothelial growth factor were found to be independent prognostic factors.

CONCLUSIONS

The expression of vascular endothelial growth factor was one of the most important prognostic factors in completely resected non-small-cell lung cancer, especially in squamous cell carcinoma.

Effects of linomide on advanced prostate-seminal vesicle cancers in Lobund-Wistar rats

BACKGROUND

Angiogenesis and antiangiogenesis, as applied to oncology, are phenomena in which (1) tumors acquire a new blood vascular system from the host that is needed for their growth progression and metastasis; and (2) factors are produced that interfere with neovascularization, thereby inhibiting growth and metastasis of the tumor. Linomide, a chemical antiangiogenesis agent, inhibited the growth of transplanted tumors in mice and rats and inhibited the early development of metastasizing tumors induced in the prostate-seminal vesicle (P-SV) complex of genetically susceptible Lobund-Wistar (L-W) rats.

METHODS

L-W rats with small induced P-SV tumors were treated with a recommended dosage of linomide (100 mg/kg BW/day) by the intraperitoneal and oral routes. The rats were monitored for the next 1-2 months, and the primary and metastatic tumors were compared with related data in drug-free tumor-bearing control rats.

RESULTS

P-SV tumors in linomide-treated and untreated control rats continued to grow, except that in the former (1) the tumors were marginally smaller, (2) the centers of the primary P-SV tumors had failed to grow, (3) the peripheral areas of the tumors contained actively proliferating tumor cells, and (4) metastatic P-SV tumors in the lungs were disrupted with focal areas of necrosis, but areas of intact tumor cells survived. Spread of tumor cells into the peritoneal cavity was not inhibited. Rats on orally administered linomide lived significantly longer than rats inoculated by the intraperitoneal route and untreated control rats. The dosage of linomide used showed evidence of toxicity.

CONCLUSIONS

Although primary and metastatic P-SV tumors were damaged in L-W rats treated with linomide, this antiangiogenic drug was of minimal therapeutic benefit to rats in which a palpable P-SV tumor had developed before onset of treatments.

Correlation between basic fibroblast growth factor immunostaining of stromal cells and stromelysin-3 mRNA expression in human breast carcinoma

We examined the localization of basic fibroblast growth factor (bFGF) in a series of human breast carcinomas using immunohistochemistry. Staining was observed in tumour cells in 15 out of 54 (28%) tumours and in the adjacent stroma in 34 out of 54 (63%) tumours examined. No correlation was observed between positive staining of these two compartments. The relationship between bFGF staining and expression of the metalloprotease stromelysin-3, and between bFGF and microvessel density, was examined. A statistically significant correlation (P < 0.003) was observed between bFGF staining of the stromal compartment and high expression of stromelysin-3 (ST-3; MMP-11) metalloprotease mRNA by stromal cells. In contrast, no correlation was observed between bFGF and intratumour microvessel density (IMD). These results raise the possibility that bFGF may be involved in the induction of stromelysin-3 mRNA expression in breast cancer stroma.