Angiogenetic protooncogene ets-1 induced neovascularization is involved in the metastatic process of testicular germ cell tumors

BACKGROUND: Induction of angiogenesis is essential for tumor growth and metastasis. The role of angiogenetic factors and corresponding microvessel density in the development of metastasis of nonseminomatous testicular germ cell tumors (NSGCTs) is not clearly defined. Aim of the study was to gain new insights in the expression of the above described factors in different histological subtypes of metastatic and non-metastatic NSGCTs. METHODS: Paraffin-embedded tissues of 39 NSGCTs (19 organ confined NSGCTs, pathological stage I and 20 NSGCTs with metastasis, pathological stage II) were immunohistochemical stained with antibodies for vascular endothelial growth factor (VEGF) with the ligands flt and flk, for the angiogenetic factor ets-1 as well as for endothelial markers CD34 and CD105. Areas representative of the invasive tumor were selected and the different histological subtypes were microdissected. For each subtype immunohistochemical expression in metastatic and organ confined tumors was assessed. Additionally, neovascularization was investigated by microvessel density and correlated to the markers of angiogenesis. RESULTS: VEGF expression was most often seen in teratoma components. There was no significant difference in the expression of VEGF, flt or flk in metastatic vs. organ confined tumors and their different histological subtypes seen. Only frequency and intensity for ets-1 expression differed significantly between metastatic and non-metastatic tumors. Using CD105 a significantly higher microvessel density was observed in stage II tumors. In addition, microvessel density determined by CD105 correlated significantly with ets-1 expression. DISCUSSION: VEGF and its receptors flt and flk seem not be involved in the progress of metastatic development of NSGCTs. Only expression of ets-1, a protooncogene involved in tumor angiogenesis, was significantly higher and more frequently seen in metastatic NSGCTs. A difference in microvessel density between tumor stages could only be observed if the specific CD105 antibody was used. In contrast, no difference in microvessel distribution between histological subtypes or tumor stages was observed if the pan-endothelial marker CD34 was used. Furthermore, ets-1 expression was significantly associated with CD105 microvessel density. Conclusively, ets-1 together with microvessel density determined by CD105 may have prognostic value in the multistep event of carcinogenesis.     

p53 and microvessel density in primary resection specimens of superficial bladder cancer

PURPOSE: p53 Regulates angiogenesis in fibrosarcoma and correlative studies suggest a similar role for muscle invasive bladder cancer. We evaluated the associations of p53 status and microvessel density with pathological features and clinical outcomes in a large population of patients with superficial bladder cancer. In addition, we assessed the correlation of p53 status with microvessel density, which would suggest the regulation of angiogenesis by p53. MATERIALS AND METHODS: We stained 84 primary bladder resection specimens, including 55 stage pTa, 29 stage pT1, 27 grade 1, 35 grade 2 and 22 grade 3 samples, for p53, CD31 and CD34. The relationships of p53 or microvessel density and tumor stage-grade or clinical recurrence-progression were analyzed by analysis of variance and pairwise comparison analysis for least significant difference, and Pearson correlation coefficients. Only patients with no previous biopsy were included in analysis to preclude interference by granulation tissue related neovascularization. The 4 samples with significant inflammation were also excluded from study. RESULTS: At a mean followup of 33 months (range 1 to 93) 34 of 84 patients (40.4%) experienced 1 or more tumor recurrences and 10 (11.9%) had stage and/or grade progression. Statistically significant associations were observed of p53 immunostaining and microvessel density with tumor stage and grade (p <0.05). However, the association of p53 status with microvessel density was weak and not statistically significant. Similar results were observed for the CD31 and CD34 based estimates of microvessel density. Neither p53 status nor microvessel density correlated with recurrence or progression. CONCLUSIONS: Our study confirms the strong association of p53 and microvessel density with the well established prognostic factors of grade and stage in superficial bladder cancer, supporting other evidence of an important role for p53 and angiogenesis in the tumor biology of this disease. However, our data argue against a primary role of p53 in the regulation of angiogenesis in superficial bladder cancer. This study, which to our knowledge is the first to focus on primary resection specimens, suggests that other genetic or environmental factors may contribute to the regulation of angiogenesis in superficial bladder cancer.     

结直肠癌组织中巨噬细胞表达胸苷磷酸化酶并与血管新生相关

目的探讨结直肠癌组织中胸苷磷酸化酶(dThdPase)表达与血管新生的相互关系。方法采用抗dThdPase、抗巨噬细胞标记物CD68和抗血管内皮细胞标记物CD34的单克隆抗体,对40例结直肠癌手术切除标本进行免疫组织化学染色分析,对其中27例标本同时测定其癌组织和周围正常组织的dThdPase活性(HPLC法)。并应用ELISA法分别检测结直肠癌细胞系LS174T、CloneA、Colo320、CX-1、Lovo、MIP101和类巨噬细胞系THP-1和U937的dThdPase蛋白含量。结果结直肠癌组织中的dThdPase活性明显高于周围正常肠组织(P<0.01)。dThdPase阳性细胞几乎都是癌巢周围的间质细胞,特别是肿瘤相关巨噬细胞(TAM)。且TAM与dThdPase阳性细胞的分布区域几乎完全一致。癌巢周围新生血管数明显多于正常肠黏膜组织(P<0.01)。TAM计数、dThdPase阳性间质细胞计数和微血管计数3者互成正相关。除LS174T检出微量和Lovo检出少量dThdPase蛋白外,其他4株癌细胞未检出。而THP-1和U937的dThdPase蛋白含量分别为18.2U/mg和19.3U/mg。结论结直肠癌组织中增高的dThdPase活性主要由TAM表达,增多的TAM与结直肠癌的血管新生相关。     

HSP60在胃癌中的表达与微血管生成的关系及临床意义

目的：观察热休克蛋白（HSP60）在胃癌组织中的表达以及其与肿瘤微血管生成的关系。方法：采用免疫组化SP法检测85例胃癌组织和35例癌旁正常胃组织中HSP60蛋白的表达;通过测定CD34来衡量微血管密度（MVD）。结果：胃癌组织HSP60表达明显高于癌旁正常胃组织（P〈0.01）,其中HSP60的表达与肿瘤的大小、分化和浸润程度密切相关（P〈0.05）;胃癌组织MVD与肿瘤大小和浸润程度密切相关（P〈0.05）;MVD与HSP60的蛋白在胃癌组织中的表达高度相关（r=0.404,P〈0.05）。结论：HSP60的高表达与肿瘤微血管生成及肿瘤的进展密切相关,可作为评估胃癌患者预后的重要参考指标。     

The relationship between angiogenesis and cyclooxygenase-2 expression in prostate cancer

OBJECTIVE: To test the hypothesis that angiogenesis in prostate cancer is associated with tumour invasion and metastasis, and that this is mediated through increased cyclooxygenase-2 (COX-2) expression. PATIENTS AND METHODS: Angiogenesis was assessed in 105 patients with either prostate cancer (79) or benign prostatic hyperplasia (BPH, 26) and these data correlated with levels of COX-2 expression in the same dataset. The mean microvessel density (MVD) was analysed as a marker of angiogenesis, using the endothelial antigen CD34 stained by immunohistochemistry. RESULTS: There was no difference in MVD in progressive tumour stages compared with BPH. There was a negative correlation between MVD and COX-2 expression, but the effect of increased COX-2 expression on MVD was not marked. CONCLUSION: These data suggest that COX-2 drives tumour spread in prostate cancer by means other than the promotion of angiogenesis.     

CD146与VEGF在人肝细胞癌组织中的表达及其临床意义

目的 该研究旨在观察人肝细胞癌(hepatocellular carcinoma,HCC)组织中CD146与VEGF的表达及其关系,探讨它们在HCC中与血管生成的关系及其临床意义.方法 采用免疫组化法检测60例HCC癌组织及癌旁肝组织中CD146、VEGF的表达情况,用CD34标记免疫组化法检测微血管密度(microvessel density,MVD),分析它们的表达与临床病理指标的关系.结果 CD146、VEGF在癌组织中的阳性率分别为66.67%和63.33%,而在癌旁组织中的阳性率分别为30%和33.33%,癌组织与癌旁组织比较差异有显著性(P＜0.05).癌组织的MVD为54.92±8.55/200倍视野,癌旁组织的MVD为21.36±6.63/200倍视野,两者差异有显著性(P＜0.05).与癌旁组织相比,癌组织中CD146、VEGF表达及MVD明显增加.CD146在人肝癌组织中的表达与临床分期、门静脉癌栓及肝外转移明显有关,而与术后复发、肿瘤个数、肿瘤直径、血清AFP水平及肿瘤分化程度无明显关系.VEGF在人肝癌组织中的表达与术后复发、肝外转移、临床分期、门静脉癌栓、肿瘤直径相关,而与肿瘤个数、血清AFP水平及肿瘤分化程度无明显关系.在癌组织中MVD与CD146、VEGF的表达呈正相关,CD146与VEGF亦呈正相关.结论 肝癌组织中CD146及VEGF高表达,与肿瘤血管形成和转移密切相关,分析它们的表达有助于综合判断HCC的预后.     

Lymph and blood vessel architecture in benign and malignant prostatic tissue: lack of lymphangiogenesis in prostate carcinoma assessed with novel lymphatic marker lymphatic vessel endothelial hyaluronan receptor (LYVE-1)

PURPOSE: Due to the lack of specific markers the analysis of lymphatic vessel density (LVD) has been almost impossible in the past. We report the novel specific marker for lymphatic endothelium, lymphatic vessel endothelial hyaluronan receptor (LYVE-1), in prostatic, benign prostatic hyperplasia (BPH) and prostate cancer (PCa) tissue. Normal blood vessels were additionally quantified in BPH and PCa. MATERIALS AND METHODS: LYVE-1 lymphatics (LVD) and CD34 blood vessels were assessed in 20 paraffin sections of BPH and 50 of PCa tissue by immunohistochemistry in a standardized experimental setting. The regions of PCa, periphery of the tumor and nontumorous regions of the PCa specimens, and BPH tissue were evaluated. Double staining was done (LYVE-1/CD34). Acquired data were interrelated and compared to the pathological parameters of the specimens. RESULTS: Double staining revealed numerous CD34 blood vessels but only a few LYVE-1 lymphatic vessels in BPH and PCa sections. Mean LVD +/- SD was distinctly lower (0.55 +/- 0.93) in PCa tissue than in tumor periphery (2.45 +/- 1.93) and nontumorous (3.16 +/- 2.23) tissue (p <0.0001). Maximum LVD was observed in BPH (7.17 +/- 3.61), which differed markedly from nontumorous areas of PCa specimens (p <0.001). In contrast to LVD, significantly more blood vessels were found in PCa (116.00 +/- 39.25) than in BPH (60.30 +/- 19.34) tissue (p <0.001). CONCLUSIONS: LYVE-1 is a specific lymphatic endothelial marker in benign and malignant prostate tissues. It is a useful new marker for the investigation of lymphatics. To our knowledge we report the immunohistochemical visualization and quantification of lymphatic vessels in prostatic tissue for the first time. In contrast to the stimulated angiogenesis of blood vessels in PCa, the destruction of lymphatic vessels occurs rather than lymphangiogenesis.     

Breast cancer angiogenesis: A quantitative morphologic and doppler imaging study

Background: Tumor growth and metastases require the development of new vessels (angiogenesis). Angiogenesis, assessed by microvessel count using immunocytochemical stain of endothelial cells, has been shown to predict metastases and correlate with early death. Recently developed color Doppler mapping can detect the “tumor flow signals” in breast cancer and help to distinguish it from benign lesions. The question is, does this tumor vascularization assessed by color Doppler mapping correlate with the angiogenesis assessed by immunocytochemistry? Methods: Eighty-four patients admitted for breast surgery were studied. The final diagnosis was made by pathology for 52 malignancies and 32 benign lesions. The color Doppler mapping of the breast lesion was made preoperatively. The following parameters were assessed: (a) vessel location (peripheral or central); (b) density of color Doppler signals; and (c) maximum systolic velocity. Tumor angiogenesis was assessed by microvessel count under light microscopy using the platelet/endothelial cell adhesion molecule antibodies (CD31) method. The correlation between maximum velocity and microvessel count of breast cancer was examined. The clinical significance of maximum flow velocity of breast cancer with various clinicopathologic factors was assessed. Results: Color signals were detected in 48 cases of 52 malignancies (92%). All tumors demonstrated signals at the periphery of the lesion but in only 13 (27%) were the signals detected within the tumor. Color signals were scored as + + or + + + in 44 (92%) patients. Pulsed wave blood flow was shown in all these 48 tumors, with maximum velocities varying from 4 to 36 cm/s. Among the 32 benign lesions, color signals were detected in 10 (31%) and all were peripheral and scored subjectively as +. Evaluation of these color Doppler mapping parameters shows no significant correlation with microvessel counts using CD31 monoclonal antibodies. However, there was a positive association (p<0.05) between nodal metastases and higher tumor flow velocity in T1 (<2 cm) breast tumors but not in larger tumors. Conclusion: Although the color Doppler mapping has been shown to be useful in distinguishing benign from malignant breast lesions, the intensity of signal and velocity of flow had no correlation with the extent of angiogenesis of breast cancer. The presence of high-flow tumor signal in early breast carcinoma is significantly associated with the presence of axillary lymph node metastases.     

Microvessel density and regulators of angiogenesis in malignant and nonmalignant prostate tissue

The aim of this study was to investigate the relationship between microvessel density (MVD), positive and negative angiogenic factors, and established prognostic factors in prostate cancer (PC), and, to clarify the effect of angiogenic factors to angiogenesis. The vascularization of neoplastic, non-neoplastic prostate tissue was determined by CD34 immunostaining. Angiogenetic mediators VEGF, bFGF, TSP-1, and p53 were studied by immunohistochemistry. Neovascularization and p53, VEGF, and TSP-1 expressions of tumorous tissue were higher than non-tumorous tissue.The bFGF expression in these tissues was not different.The p53 expression was not correlated with the expressions of VEGF, bFGF, and TSP-1 in PC. Our results demonstrate a significant increase in MVD, VEGF, TSP-1, and p53 expressions in prostate tumorigenesis. The pretreatment sPSA was the only parameter demonstrating significant correlation with tumor grade and may have a value in the prediction of aggressive tumor behavior in PC.     

Impact of microvessel density on lymph node metastasis and survival after curative resection of pancreatic cancer

Purpose  

The roles of angiogenesis and the most prominent angiogenic vascular endothelial growth factor (VEGF) in diseases of the pancreas remain controversial. We compared microvessel density (MVD) and VEGF status in normal pancreatic, chronic pancreatic, and pancreatic cancer (PC) tissues to establish their prognostic relevance.     

Vascular endothelial growth factor and its correlation with angiogenesis and p53 expression in prostate cancer

BACKGROUND: Previously it was demonstrated that in prostate tumors, angiogenesis measured as microvessel density (MVD) is associated with tumor stage as well as WHO grade and is an independent predictor of clinical outcome. Vascular endothelial growth factor (VEGF) is a major inducer of angiogenesis. There is some evidence that P53 mutations cause overexpression of VEGF. We studied VEGF expression, p53 overexpression, and P53 mutations in prostate cancer (PCA) to investigate the role of VEGF as an angiogenic marker and the possible deregulation of VEGF as a result of P53 mutations in PCA. METHODS: Immunohistochemical staining with a polyclonal VEGF antibody was performed in 55 paraffin-embedded PCA, in which MVD had previously been determined, as well as in 5 prostatic adenomas (PA) and 20 adjacent normal prostate tissues. In addition, 37 PCA and 5 PAs were examined for p53 expression by immunohistochemistry. Temperature gradient gel electrophoresis (TGGE) was performed in 13 of these PCA to screen for P53 mutations. VEGF expression, p53 expression, and mutations were then correlated with tumor stage, grade, MVD, and clinical outcome. RESULTS: While PA and normal prostate tissue generally showed no or only low VEGF expression, there was a significant increase in VEGF expression with tumor stage, grade, and MVD in PCA. During clinical follow-up (mean, 31.9 months), 9 of 55 patients had tumor progression. Significant differences in VEGF expression were found between patients with tumor progression and those without (P = 0.0004). Of the 37 PCA evaluated for p53 expression, 12 exhibited p53 overexpression. TGGE revealed P53 mutations in 3 of 13 PCA. However, there was no correlation between VEGF expression, p53 overexpression, and P53 mutation, respectively. CONCLUSIONS: VEGF seems to be an important, clinically relevant inducer of angiogenesis in PCA. VEGF expression was shown to correlate positively with tumor stage, grade, MVD, and clinical outcome. However, regulation of VEGF in PCA appears to be independent of p53 expression.     

经尿道前列腺电切术中出血与前列腺增生组织MVD、VEGF的关系

目的通过检测经尿道前列腺电切（TURP）术后前列腺增生组织血管内皮生长因子（VEGF）的蛋白表达、微血管密度（MVD）,对照术中出血量,探讨其间的相关性。方珐采用免疫组化方法,对徐州市第二人民医院2005年2月～2007年6月的100例TuRP组织按前列腺体积进行分组,按病理学类型分别进行血管标记和染色检测MVD及VEGF的表达。采用氰化高铁血红蛋白比色计算术中出血量,并与病理学分类及MVD、VEGF进行比较。结果1。0例患者中,同体积前列腺术中出血量与MVD、VEGF呈明显相关性。MVD、VEGF高表达者术中出血多（P〈0．05）。随体积增大（〉60mL）,前列腺增生病理类型发生变化,但术中出血量与前列腺体积大小不一致,而与MVD、VEGF表达呈正相关。结论TURP术中出血量与前列腺病理学类型相关,组织MVD、VEGF表达高者,术中出血量多。     

Blood vessels are regulators of growth, diagnostic markers and therapeutic targets in prostate cancer

The vasculature plays an important role in the normal and malignant prostate. Under basal conditions both glandular epithelial and stromal prostate cells produce an abundance of blood flow and angiogenesis regulating substances and the expression of these is generally increased in prostate tumors. The proportion of proliferating endothelial cells is high in the normal prostate compared to other tissues in the body. After castration effects on the vasculature, such as decreased blood flow and vascular regression, precede effects on the glandular compartment. Correspondingly, hormone induced prostate growth is characterized by early effects on the vasculature such as increased blood flow and endothelial cell proliferation, thus indicating that the vasculature may be involved in the androgenic regulation of the prostate. Prostatic intraepithelial neoplasia (PIN) and prostate cancer are associated with increased vascular density and in experimental models prostate cancer growth is apparently angiogenesis-dependent since tumor growth and progression can be inhibited by antiangiogenic treatment. Moreover, vascular density has been related to prognosis in prostate cancer patients. A better understanding of the pathways regulating angiogenesis in the normal prostate and how these pathways change during malignant transformation can hopefully lead to better prognostic markers and therapies for the large group of patients with prostate cancer. The purpose of this review is therefore to summarize the current knowledge on the role and regulation of the vasculature in the prostate and its potential clinical applications.     

Vascular endothelial growth factor content in metastasizing and nonmetastasizing Dunning prostatic adenocarcinoma

BACKGROUND: Tumor angiogenesis is important in progressive tumor growth and metastasis. In the normal rat prostate and in androgen-sensitive prostate tumors androgen ablation causes an involution of the vasculature and a decrease in the vascular endothelial growth factor (VEGF) levels before regression of the prostate gland. To examine whether angiogenesis and metastasis are regulated by VEGF in androgen-insensitive and metastasizing prostate tumors, five Dunning rat prostate cancer sublines were tested; the androgen-sensitive, nonmetastasizing R3327 PAP, and the androgen-insensitive, low metastasizing AT-1, and the three androgen-insensitive, metastasizing AT-2, AT-3, and MatLyLu Dunning prostatic adenocarcinomas. METHODS: VEGF levels were quantified in the rat dorsolateral prostate and in the five Dunning sublines using competitive RT-PCR, Western blot, and Elisa. Vascular density was determined by factor VIII staining. RESULTS: VEGF mRNA was increased in all tumors compared with normal prostates. The two metastatic sublines AT-3 and MatLyLu and the nonmetastatic subline AT-1 showed the highest VEGF mRNA expression. VEGF protein levels in the prostate gland showed increased expression in the metastatic sublines, AT-2, AT-3, and MatLyLu, compared with the nonmetastatic AT-1 subline and the ventral prostate. VEGF proteins in serum were highest in the metastatic AT-3 subline. The vessel density was highest in the two highly metastatic sublines AT-3 and MatLyLu. CONCLUSIONS: Our results suggest that VEGF levels are associated with microvessel density and the previously established metastatic pattern of these rat prostate tumor systems.     

The effect of finasteride on the expression of vascular endothelial growth factor and microvessel density: a possible mechanism for decreased prostatic bleeding in treated patients

PURPOSE: Several studies have confirmed the benefit of finasteride in limiting hematuria from benign prostatic hyperplasia. Vascular endothelial growth factor (VEGF), a potent stimulator of angiogenesis, and microvessel density have been independently evaluated in the mechanism of decreased bleeding observed in patients treated with finasteride. We evaluated the expression of VEGF and suburethral prostatic microvessel density in patients with benign prostatic hyperplasia treated with finasteride. MATERIALS AND METHODS: The study included 24 patients undergoing prostatic surgery for benign disease, of whom 12 were given finasteride for a minimum of 6 weeks before surgery and the remaining 12 served as controls. Sections from the prostatic urothelium and hyperplastic prostate were individually stained for CD34 specific for nascent blood vessels and VEGF. Analysis of each specimen was performed in a blinded fashion. Microvessel density was calculated by counting the number of positively stained blood vessels on 10 consecutive, nonoverlapping, high power fields within the suburethral and hyperplastic prostate compartments. VEGF expression was examined by immunohistochemistry. Statistical analysis of the results was performed using Student's t test. RESULTS: Prostatic suburethral VEGF expression and microvessel density were significantly lower in the finasteride group compared to controls (p <0.05). Differences in VEGF expression and microvessel density at the level of the hyperplastic prostate were not found to be significantly different between the 2 groups.CONCLUSIONS Decreased expression of VEGF by finasteride inhibits angiogenesis and significantly decreases microvessel density in prostatic suburethral tissue. This sequential relationship provides histochemical insight into the mechanism by which finasteride reduces prostatic urethral bleeding.     

Expression of pro-angiogenic growth factors VEGF,EGF and bFGF and their topographical relation to neovascularisation in prostate cancer

The aim of the study was to quantify the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) in prostate cancer and adjacent non-tumorous tissue in a standardized experimental set-up and to evaluate the paracrine effects of three endothelial stimuli on neovascularisation. Immunohistochemical staining of prostate cancer (PCa) specimens for VEGF, bFGF, EGF and the endothelial marker CD31 was performed (n=56). Sections were analyzed for growth factor-positive cancer/epithelial cells as well as staining intensity in (I) malignant and (II) non-tumorous tissue. Within PCa the topographic relationship (TR) of maximum microvessel density (MWD) and maximum expression of each growth factor was assessed. The number of VEGF- and EGF-positive cells in PCa was significantly enhanced compared with non-tumorous tissue (p<0.0001), whereas there was no difference in staining intensity. In contrast, the staining intensity of bFGF sections revealed a stronger expression in non-tumorous tissue compared with PCa (p<0.0001). In benign glands, VEGF, EGF and bFGF expression is chiefly restricted to basal cells. VEGF and EGF displayed a close TR in 65 and 57% of cases, respectively, whereas bFGF revealed a close TR in only 43% of PCa specimens. The results outline the relationship of the investigated growth factors and angiogenesis in PCa, which is strongest for VEGF and EGF. The relevance of VEGF and EGF is underlined by the increased number of positive cancer cells. Although previously reported to be a pro-angiogenic growth hormone, bFGF appears to play an assimilably minor role in the angiogenesis of PCa.This project was supported by a grant from the Reinhard Nagel Trust, Germany     

前列腺癌TSP-1的表达与血管新生的关系及意义

目的：探讨良性前列腺增生及前列腺癌中血管生成与血小板反应素-1（TSP-1）表达的相关性。方法：应用免疫组织化学方法检测32例良性前列腺增生和32例前列腺癌组织中TSP-1的表达及微血管密度（MVD）。结果：前列腺癌组织中TSP-1表达显著低于良性前列腺增生（P〈0．05）,MVD则明显升高（P〈0．05）;随着肿瘤分期的进展,浸润转移性癌中TSP-1的表达降低甚至缺失,而MVD却逐渐升高。结论：TSP-1在前列腺癌中呈低表达,与前列腺癌的血管新生相关;作为一种内源性血管新生抑制剂,它具有抑制肿瘤生长及血管新生的作用。     

Treatment of Human Pancreatic Cancer in Mice with Angiogenic Inhibitors

Tumor growth is dependent on the balance of positive and negative regulators of angiogenesis. Antiangiogenic compounds inhibit endothelial cell biology in vitro and angiogenesis in vivo. Therefore antiangiogenic therapy presumes to be an effective treatment for pancreatic cancer. We wanted to determine the effect of antiangiogenic therapy on the growth of human pancreatic cancer in a mouse model. The angiogenesis inhibitors TNP-470 and antiangiogenic antithrombin III (aaATIII) were tested in vitro for their ability to inhibit endothelial cell proliferation. These inhibitors, along with the known antiangiogenic molecule endostatin, were then employed to treat two different primary human pancreatic cancers implanted subcutaneously into the dorsa of immunodeficient (SCID) mice. Treated tumors were examined histologically for microvessel density, apoptosis, and proliferation. All three inhibitors suppressed the growth of pancreatic tumors in vivo. Immunohistochemical analysis revealed increased degrees of apoptosis and reduced microvessel density in treated tumors compared to untreated tumors, although tumor cell proliferation was the same in both groups. None of the inhibitors tested significantly inhibited proliferation of human pancreatic cancer cells, although both TNP-470 and aaATIII were able to inhibit the proliferation of endothelial cells. The observed tumor suppression may be due to increased tumor cell apoptosis as a result of capillary dropout. These studies show that after the angiogenic switch in a human tumor, there is residual production of angiogenesis inhibitors.     

Tumor angiogenesis is associated with progression after radical prostatectomy in pT2/pT3 prostate cancer

BACKGROUND: The clinical relevance of tumor angiogenesis has been investigated in several human tumor types. Angiogenesis (measured as microvessel density; MVD) was recently correlated with tumor stage, grade, and clinical course in prostate cancer (PC). However, considerable controversy remains concerning the prognostic value of angiogenesis in PC. METHODS: We examined MVD in primary PCs to further establish the prognostic relevance of angiogenesis in this tumor entity. In 98 paraffin-embedded PCs of various stages, 5 prostate adenomas, and 20 normal prostate tissues, MVD was determined immunohistochemically using a polyclonal antibody against factor VIII. The findings were correlated with the clinical data of the patients. RESULTS: Normal prostate tissue and prostate adenomas had a low MVD. In PC, MVD increased significantly with tumor stage and grade (P < 0.001). The Wilcoxon rank statistics showed significant differences for MVD (P < 0.0001), tumor stage (P < 0. 0027), and grade (P < 0.0001), but not for preoperative prostate-specific antigen values in PC patients with and without tumor progression subsequent to treatment, respectively. Importantly, multivariate survival analysis revealed that MVD and tumor grade were the only independent markers for progression in prostate carcinoma. CONCLUSIONS: In this study, tumor angiogenesis measured by MVD was associated with a dismal pathologic appearance and a negative clinical prognosis in PC after radical prostatectomy.