Tumour angiogenesis

Diagnostic Value and Application of Infrared Thermography in the Analysis of Circumanal Gland Tumors

In dogs, circumanal tumors are the third most common skin neoplasm. Circumanal gland adenomas (CAGAs) have a good prognosis. Contrastingly, circumanal gland adenocarcinomas (CAGAC) have high relapse rates and may be metastatic. This study aimed to investigate the utility of thermal imaging as an ancillary modality for the diagnosis of canine CAGA and CAGAC. We analyzed the following parameters: SpT, temperature measured at the tumor center; SpNT, temperature measured at a healthy sphincter skin spot distant from the tumor; TA, temperature measured at a tumor-encompassing ellipse-shaped area; and NTA, temperature measured at an ellipse-shaped area of the healthy sphincter skin distant from the tumor. In CAGAs, the mean SpT and SpNT temperature values differed by −1.45°C (p < 0.01) while the mean TA and NTA temperature values differed by −0.96°C (p < 0.05). In CAGACs, mean SpT and SpNT temperatures differed by −1.71°C (p < 0.01) while the mean TA and NTA temperatures differed by −1.69°C (p < 0.01). The mean SpT and TA temperature values measured in CAGAs and CAGACs differed by −0.10°C (p = 0.87) and 0.52°C (p = 0.38), respectively. Both tumors were colder than healthy sphincter skin. However, a substantial number of CAGACs were colder than CAGAs. Temperature differences ≥ 1°C between tumors and healthy sphincter skin increased the probability of CAGAC diagnosis by 17.45%. Thermal imaging allowed discrimination between healthy and tumoral tissues; therefore, it could be a good ancillary diagnostic modality.

Restraint stress abates the antioxidant potential of melatonin on dimethyl benz (a) anthracene (DMBA) induced carcinogenesis

Free radical involvement in initiation, promotion and progression of carcinogenesis, implicates that scavengers of free radicals may act as inhibitors in the carcinogenic process. Melatonin, an antioxidant was used in the present study to evaluate its effectiveness on skin carcinogenesis induced by DMBA both with and without chronic restraint stress (CRS). Fifty Swiss albino young male rats were divided into five groups of 10 rats each as controls, topical DMB alone, Pre CRS-DMBA, melatonin DMBA and Pre-CRS-DMBA-melatonin treated groups. After 18 weeks blood was collected along with liver and skin samples. These were used for antioxidant enzyme assay, DNA damage and fluorescent spectra analysis. Melatonin showed antioxidant potential in combatting DMBA induced skin carcinogenesis measured by free radical scavenging enzymes and in vivo antioxidant status, DNA damage. Sensitive detection of the DMBA induced micro biochemical changes was possible by fluorescent spectroscopy from the transformed ratio of fluorescent intensity (F1 530 nm/630 nm) otherwise found constant for normal tissues. By melatonin treatment this ratio was similar to control values. The decreased antioxidant biochemical parameters depicting oxidative stress were comparable to comet assay and fluorescent studies, endorsing the chemo-preventive efficacy of melatonin against skin carcinogenesis caused by DMBA. CRS pre-exposure diminished the chemo-preventive/antioxidant ability of melatonin and the results were same as DMBA alone treatment, showing stress affected both cancer development and chemoprevention. CRS decreased the antioxidant potential of melatonin. Hence, managing stress could be perceived in cancer chemoprevention. Further studies focusing on stress reduction are needed.

Pre-Exposure to Chronic Unpredictable Stress Suppresses the Chemopreventive Potential of Aloe Vera (Av) Leaf Gel Against 7,12-Dimethylbenz(a)anthracene (DMBA) Induced Carcinogenesis

The present study evaluates the topical application of aloe vera (Av) leaf gel as a protective natural product against 7,12-dimethylbenz(a)anthracene (DMBA)-induced skin lesions in Swiss albino mice and as an antioxidant for the systemic toxicity of DMBA in the presence and absence of chronic unpredictable stress (CUS). Animals were randomized into seven groups and sacrificed after 16 weeks of treatment. Av gel application along with DMBA + 12-O-tetradecanoylphorbol-13-acetate (TPA) was found to be effective in reducing tumor incidence, cumulative number of papillomas, tumor burden and tumor yield when compared to untreated groups. Furthermore, topical treatment with Av gel significantly increased the overall in vivo antioxidant status of mice. Conversely, lipid peroxidation levels were significantly decreased in skin and circulation. However, pre-exposure to CUS followed by DMBA + TPA + Av gel application reduced the chemopreventive efficacy of Av gel as evidenced by increased tumor incidence, tumor burden, tumor yield and MDA levels accompanied by decrease in the enzymatic and nonenzymatic antioxidants. These observations were further supported by the results of fluorescent studies and comet assay. The study demonstrates a reduction in the antioxidant and antitumor potential of Av gel in presence of CUS thereby, signifying the need of stress reduction during cancer chemopreventive trials.

Dynamic modeling of folliculogenesis signaling pathways in the presence of miRNAs expression

Background

TEK signaling plays a very important role in folliculogenesis. It activates Ras/ERK/MYC, PI3K/AKT/mTORC1 and ovarian steroidogenesis activation pathways. These are the main pathways for cell growth, differentiation, migration, adhesion, proliferation, survival and protein synthesis.

Results

TEK signaling on each of the two important pathways where levels of pERK, pMYC, pAkt, pMCL1 and pEIF4EBP1 are increased in dominant follicles and pMYC is decreased in dominant follicles. Over activation of ERK and MYC which are the main cell growth and proliferation and over activation of Akt, MCl1, mTORC1 and EIF4EBP1 which are the main cell survival and protein synthesis factors act as promoting factors for folliculogenesis. In case of over expression of hsa-miR-30d-3p and hsa-miR-451a, MYC activity level is considerably increased in subordinate follicles. Our simulation results show that in the presence of has-miR-548v and bta-miR-22-3p, downstream factors of pathways are inhibited.

Conclusions

Our work offers insight into the design of natural biological procedures and makes predictions that can guide further experimental studies on folliculogenesis pathways. Moreover, it defines a simple signal processing unit that may be useful for engineering synthetic biology and genes circuits to carry out cell-based computation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13048-017-0371-y) contains supplementary material, which is available to authorized users.

Tumor angiogenesis as an important prognostic factor in advanced non-small cell lung cancer (Stage IIIA)

The aim of the present study was to evaluate angiogenesis by determining the micro vascular density (MVD) and the expression of vascular endothelial growth factor (VEGF-A) in advanced non-small cell lung cancer (NSCLC) tumor samples, and to analyze their associations with clinical parameters and survival. Tumor tissue specimens of fifty patients (41 males and 9 females), who underwent radical surgical treatment for NSCLC in stage IIIA (T1-3N2) were collected for immunohistochemical analysis. MVD evaluation was performed using an anti-CD31 monoclonal antibody and VEGF-A expression using a polyclonal anti-VEGF-A antibody. The results were associated with two-year survival. Statistical analysis revealed significant associations in the level of angiogenesis (high MVD) and shorter survival of patients with NSCLC (P=0.0007). VEGF-A expression showed no association with micro vascular density (P=0.51) or survival (P=0.68). There was no significant association between MVD and VEGF-A. The measurable, clinical MVD parameters could be used as a reliable prognostic factor for the survival of patients with advanced NSCLC.

Effect of the PI3K/AKT signaling pathway on hypoxia-induced proliferation and differentiation of bone marrow-derived mesenchymal stem cells

Bone marrow-derived mesenchymal stem cell (BM-MSC) transplantation has been demonstrated to be an effective way of augmenting angiogenesis of ischemic tissue. The low oxygen conditions in ischemic tissue directly affect the biological behavior of engrafted cells. However, to date, the mechanism through which hypoxia regulates self-renewal, differentiation and paracrine function of BM-MSCs remains unclear. Clarification of this mechanism would be beneficial to the use of stem cell-based therapy. The PI3K/AKT pathway has been extensively investigated for its role in cell proliferation, cell transformation, paracrine function and angiogenesis. The present study aimed to analyze the role of PI3K/AKT pathway in hypoxia-induced proliferation of BM-MSCs and their differentiation into endothelial cells in vitro by the application of LY294002, a PI3K/AKT pathway inhibitor, with cells cultured in normoxia serving as a control. The results showed that rat BM-MSCs at passage 3 and 4 displayed only few phenotypical differences in the expression of surface antigens as detected by flow cytometry. When compared with the cells treated in normoxia, the proliferation of BM-MSCs in hypoxia was promoted, a greater number of cells expressed CD31 and a higher expression of vascular endothelial growth factor was observed after culture in hypoxic conditions. However, by inhibiting with LY294002, these changes induced by hypoxia were partly inhibited. In conclusion, the present study showed that the PI3K/AKT pathway served an important role in hypoxia-enhanced in vitro proliferation of BM-MSCs and their differentiation into endothelial cells and paracrine vascular endothelial growth factor.

The Study of MIB-1 LI and CD 34 As A Marker of Proliferative Activity and Angiogenesis in Different Grades of Meningioma

INTRODUCTION

Meningiomas comprise 24-30% of all tumours occurring in the central nervous system. Conventional morphologic critera as studied in routine Haematoxylin and Eosin stained sections (H & E) may not be accurate in grading and assessing prognosis in small stereotactic biopsy specimens. Thus, arises the need for objective methods for assessing tumour biology. Angiogenesis is a key event in the spread of tumours and denotes a poor prognosis. Intratumoural Microvessel Density (MVD) helps in quantification of angiogenesis.

AIM

To measure the proliferative index by MIB-1 and correlate it with the WHO grading of meningiomas. Also to assess the expression of CD34 in various grades of meningioma and evaluate their angiogenic potential by calculating MVD.

MATERIALS AND METHODS

Paraffin blocks of 30 surgically resected cases, 10 each of grade I, II and III meningiomas were reviewed. Tumours were graded and subtyped as per WHO criteria. Immunohistochemical staining was done with MIB-1 and CD 34 antibodies. Statistical analysis was performed using Mann - Whitney U test. p-value of < 0.05 was considered significant.

RESULTS

The male to female ratio overall was 1:1. The age of the patients ranged from 18-81 years. A 73% of patients had raised intracranial pressure and 18.4% of patients presented with seizures. The mean ± SD MIB-1 LI was 1.14 ± 0.84, 8.94 ± 2.73 and 35.62 ± 4.44 in grade I, II and III tumours respectively which was statistically significant. (p< 0.01). The mean ± SD MVD was 49.67 ± 22.35, 41.37 ± 7.45 and 47.86 ± 10.77 respectively in grade I, II and III tumours (p NS).

CONCLUSION

MIB-1 LI is an important complementary tool to accurately grade meningothelial tumours and assess tumour biology. Specific cycling endothelial markers along with CD 34 & MVD could be used to assess the prognosis of these tumours.

Long-term exercise training as a modulator of mammary cancer vascularization

BACKGROUND

Breast cancer remains a leading cause of death by cancer worldwide. It is commonly accepted that angiogenesis and the expression of angiogenic factors such as vascular endothelial growth factor-A (VEGF-A) is associated with the increased risk of metastasis and poor patient outcome.

OBJECTIVE

This work aimed to evaluate the effects of long-term exercise training on the growth and vascularization of mammary tumors in a rat model.

MATERIALS AND METHODS

Fifty female Sprague-Dawley rats were divided into four groups: two N-methyl-N-nitrosourea (MNU)-exposed groups (exercised and sedentary) and two control groups (exercised and sedentary). MNU was administered once, intraperitoneally at 7 weeks-old. Animals were then exercised on a treadmill for 35 weeks. Mammary tumors were evaluated using thermography, ultrasonography [Power Doppler (PDI), B Flow and contrast-enhanced ultrasound (CEUS)], and immunohistochemistry (VEGF-A).

RESULTS

Both, MNU sedentary and exercised groups showed 100% of tumor incidence, but exercised animals showed less tumors with an increased latency period. Exercise training also enhanced VEGF-A immunoexpression and vascularization (microvessel density, MVD) (p<0.05), and reduced histological aggressiveness. Ultrasound and thermal imaging analysis confirmed the enhanced vascularization of tumors on exercised animals.

CONCLUSION

Long-term exercise training increased VEGF-A expression, leading to enhanced tumor vascularization and reduced tumor burden, multiplicity and histological aggressiveness.

The twisted survivin connection to angiogenesis

Survivin, a member of the inhibitor of apoptosis family of proteins (IAPs) that controls cell division, apoptosis, metastasis and angiogenesis, is overexpressed in essentially all human cancers. As a consequence, the gene/protein is considered an attractive target for cancer treatment. Here, we discuss recent findings related to the regulation of survivin expression and its role in angiogenesis, particularly in the context of hypoxia. We propose a novel role for survivin in cancer, whereby expression of the protein in tumor cells promotes VEGF synthesis, secretion and angiogenesis. Mechanistically, we propose the existence of a positive feed-back loop involving PI3-kinase/Akt activation and enhanced β-Catenin-TCF/LEF-dependent VEGF expression followed by secretion. Finally, we elaborate on the possibility that this mechanism operating in cancer cells may contribute to enhanced tumor vascularization by vasculogenic mimicry together with conventional angiogenesis.

Immunohistochemical expression of vascular endothelial growth factor in canine oral squamous cell carcinomas

Angiogenesis is crucial for the growth and metastasis of malignant tumours, and various proangiogenic factors promote this process. One of these factors is vascular endothelial growth factor (VEGF), which appears to play a key role in tumour angiogenesis. The aim of the present study was to assess whether VEGF expression is associated with angiogenesis, disease progression and neoplastic proliferation in canine oral squamous cell carcinoma (OSCC) tissue. VEGF immunoreactivity was quantified by immunohistochemistry in 30 specimens, including normal oral mucosa and OSCC tissues graded as well, moderately or poorly differentiated. VEGF expression was correlated with tumour cell proliferation, as assessed using the proliferating cell nuclear antigen (PCNA) marker and microvessel density (data already published). The present results revealed that VEGF and PCNA expression increased significantly between normal oral tissue and neoplastic tissue, and between well and moderately/poorly differentiated tumours. In addition, VEGF expression was strongly correlated with PCNA expression and microvessel density. It was concluded that VEGF may promote angiogenesis through a paracrine pathway, stimulating endothelial cell proliferation and, similarly, may induce tumour cell proliferation through an autocrine pathway. The present results suggest that the evaluation of VEGF may be a useful additional criterion for estimating malignancy and growth potential in canine OSCCs.

Correlation between selected angiogenic markers and prognosis in pediatric adrenocortical tumors: Angiogenic markers and prognosis in pediatric ACTs

BACKGROUND/PURPOSE

Pediatric adrenocortical tumor (ACT) remains a challenging disease. Tumor weight and disease stage are still the most used indicators to prognosis and guidance of clinical decisions. Histology has not added meaningful data for risk stratification and management. ACT is metabolically active, highly vascularized, locally invasive and has the propensity to produce distant metastasis. Our objective was to correlate the expression of vascular endothelial growth factor (VEGF) and intratumoral microvessel density (MVD) with clinical and prognostic aspects in pediatric ACT.

PROCEDURE

In 27 tumors, immunohistochemical expression of VEGF, CD105 (endoglin) and CD34 was analyzed. MVD was determined by CD34 and CD105 antibodies. MVD and VEGF expression was correlated with clinical characteristics and outcome. Normal pediatric glands were used as controls.

RESULTS

Endoglin MVD was significantly higher and CD34 MVD was significantly lower in ACT than control. The VEGF expression did not differ between groups. Cytoplasmic staining for endoglin was correlated with hypertension in ACT. Endoglin MVD greater than 1 mv/field, CD34 MVD less than 32 mv/field and VEGF expression levels above 4.8% were associated with clinical and biological indicators of poor prognosis.

CONCLUSIONS

Endoglin and CD34 MVD values are potential histological markers to refine the histologic classification of pediatric ACT.

Survivin expression promotes VEGF-induced tumor angiogenesis via PI3K/Akt enhanced β-catenin/Tcf-Lef dependent transcription

Early in cancer development, tumour cells express vascular endothelial growth factor (VEGF), a secreted molecule that is important in all stages of angiogenesis, an essential process that provides nutrients and oxygen to the nascent tumor and thereby enhances tumor-cell survival and facilitates growth. Survivin, another protein involved in angiogenesis, is strongly expressed in most human cancers, where it promotes tumor survival by reducing apoptosis as well as favoring endothelial cell proliferation and migration. The mechanisms by which cancer cells induce VEGF expression and angiogenesis upon survivin up-regulation remain to be fully established. Since the PI3K/Akt signalling and β-catenin-Tcf/Lef dependent transcription have been implicated in the expression of many cancer-related genes, including survivin and VEGF, we evaluated whether survivin may favor VEGF expression, release from tumor cells and induction of angiogenesis in a PI3K/Akt-β-catenin-Tcf/Lef-dependent manner. Here, we provide evidence linking survivin expression in tumor cells to increased β-catenin protein levels, β-catenin-Tcf/Lef transcriptional activity and expression of several target genes of this pathway, including survivin and VEGF, which accumulates in the culture medium. Alternatively, survivin downregulation reduced β-catenin protein levels and β-catenin-Tcf/Lef transcriptional activity. Also, using inhibitors of PI3K and the expression of dominant negative Akt, we show that survivin acts upstream in an amplification loop to promote VEGF expression. Moreover, survivin knock-down in B16F10 murine melanoma cells diminished the number of blood vessels and reduced VEGF expression in tumors formed in C57BL/6 mice. Finally, in the chick chorioallantoid membrane assay, survivin expression in tumor cells enhanced VEGF liberation and blood vessel formation. Importantly, the presence of neutralizing anti-VEGF antibodies precluded survivin-enhanced angiogenesis in this assay. These findings provide evidence for the existance of a posititve feedback loop connecting survivin expression in tumor cells to PI3K/Akt enhanced β-catenin-Tcf/Lef-dependent transcription followed by secretion of VEGF and angiogenesis.

The gastrin receptor antagonist netazepide (YF476) prevents oxyntic mucosal inflammation induced by Helicobacter pylori infection in Mongolian gerbils

OBJECTIVE

Long-term Helicobacter pylori infection causes gastritis leading to hypergastrinemia and predisposes to gastric cancer. Our aim was to assess the role of gastrin in oxyntic mucosal inflammation in H. pylori-infected Mongolian gerbils by means of the gastrin receptor antagonist netazepide (YF476).

DESIGN

We studied 60 gerbils for 18 months and left five animals uninfected (control group), inoculated 55 with H. pylori, and treated 28 of the infected animals with netazepide (Hp+YF476 group). Twenty-seven infected animals were given no treatment (Hp group). We measured plasma gastrin and intraluminal pH. H. pylori detection and histologic evaluations of the stomach were carried out.

RESULTS

All 55 inoculated animals were H. pylori positive at termination. Eighteen animals in the Hp group had gastritis. There was a threefold increase in mucosal thickness in the Hp group compared to the Hp+YF476 group, and a threefold increase in oxyntic neuroendocrine cells in the Hp group compared to the Hp+YF476 group (p < .05). All animals in the Hp+YF476 group had macro- and microscopically normal findings in the stomach. Plasma gastrin was higher in the Hp group than in the control group (172 ± 16 pmol/L vs 124 ± 5 pmol/L, p < .05) and highest in the Hp+YF476 group (530 ± 36 pmol/L). Intraluminal pH was higher in the Hp group than in the Hp+YF476 group (2.51 vs 2.30, p < .05).

CONCLUSION

The gastrin antagonist netazepide prevents H. pylori-induced gastritis in Mongolian gerbils. Thus, gastrin has a key role in the inflammatory reaction of the gastric mucosa to H. pylori infection in this species.

Correlation between CT perfusion parameters and microvessel density and vascular endothelial growth factor in adrenal tumors

We evaluated the correlation between computed tomography (CT) perfusion parameters and markers of angiogenesis in adrenal adenomas and non-adenomas to determine if perfusion CT can be used to distinguish between them. Thirty-four patients with pathologically-confirmed adrenal tumors (17 adenomas, 17 non-adenomas) received CT perfusion imaging before surgery. CT perfusion parameters (blood flow [BF], blood volume [BV], mean transit time [MTT], and permeability surface area product [PS]) were calculated. Tumor tissue sections were examined with immunohistochemical methods for vascular endothelial growth factor (VEGF) expression and microvessel density (MVD). The mean age of the 34 patients was 43 years. The median BV was significantly higher in adenomas than in non-adenomas [12.3 ml/100 g, inter-quartile range (IQR): 10.4 to 16.5 ml/100 g vs. 8.8 ml/100 g, IQR: 3.3 to 9.4 ml/100 g, p=0.001]. Differences in BF, MTT, and PS parameter values between adenomas and non-adenomas were not significant (p>0.05). The mean MVD was significantly higher in adenomas compared to non-adenomas (98.5 ± 28.5 vs. 53.5 ± 27.0, p<0.0001). Adenomas also expressed significantly higher median VEGF than non-adenomas (65%, IQR: 50 to 79% vs. 45%, IQR: 35 to 67%, p=0.02). A moderately strong correlation between BF and VEGF (r=0.53, p=0.03) and between BV and MVD among adenomas (r=0.57, p=0.02) exist. Morphology, MVD, and VEGF expression in adenomas differ significantly from non-adenomas. Of the CT perfusion parameters examined, both BF and BV correlate with MVD, but only BF correlates with VEGF, and only in adenomas. The significant difference in BV suggests that BV may be used to differentiate adenomas from non-adenomas. However, the small difference in BV shows that it may only be possible to use BV to identify adenomas vs. non-adenomas at extreme BV values.

Angiogenesis in canine mammary tumours: a morphometric and prognostic study

Angiogenesis in canine mammary tumours (CMTs) has been described previously; however, only the intratumoural (IT) region has been studied and information on peritumoural (PT) angiogenesis is lacking. In this study, the blood vessel density (BVD), blood vessel perimeter (BVP) and blood vessel area (BVA) in IT and PT regions of 56 benign CMTs, 55 malignant CMTs and 13 samples of normal mammary gland tissue were analyzed. In addition, the blood endothelial cell proliferation (BECP) as an indicator of ongoing angiogenesis was investigated. The prognostic value of each parameter was also examined. Blood vessels and proliferating blood endothelial cells were present in IT and PT regions of both benign and malignant tumours. The vessels in the PT region had a significantly higher area and perimeter compared with those in the IT region. Malignant tumours showed significantly more vessels with a smaller total BVA and a higher BECP compared with benign tumours and control tissue. In the PT regions there was a significantly higher BVD, BVA and BVP compared with the vessels in control tissue. Only the IT and PT BVD and PT BECP in benign tumours allowed prediction of survival. The morphology of blood vessels in CMTs shows similarities with those in human breast cancer, which strengthens the case for the use of dogs with CMTs in comparative oncology trials.

Consensus diagnoses and mode of action for the formation of gastric tumors in rats treated with the chloroacetanilide herbicides alachlor and butachlor

A panel of pathologists (Panel) was formed to evaluate the pathogenesis and human relevance of tumors that developed in the fundic region of rat stomachs in carcinogenicity and mechanistic studies with alachlor and butachlor. The Panel evaluated stomach sections stained with hematoxylin and eosin, neuron-specific enolase, and chromogranin A to determine the presence and relative proportion of enterochromaffin-like (ECL) cells in the tumors and concluded all tumors were derived from ECL cells. Biochemical and pathological data demonstrated the tumor formation involved a nongenotoxic threshold mode of action (MOA) initially characterized by profound atrophy of the glandular fundic mucosa that affected gastric glands, but not surface epithelium. This resulted in a substantial loss of parietal cells and a compensatory mucosal cell proliferation. The loss of parietal cells caused a marked increase in gastric pH (hypochlorhydria), leading to sustained and profound hypergastrinemia. The mucosal atrophy, together with the increased gastrin, stimulated cell growth in one or more ECL cell populations, resulting in neoplasia. ECL cell autocrine and paracrine effects led to dedifferentiation of ECL cell tumors. The Panel concluded the tumors develop via a threshold-dependent nongenotoxic MOA, under conditions not relevant to humans.

Transcriptional profiling of mouse uterus at pre-implantation stage under VEGF repression

Uterus development during pre-implantation stage affects implantation process and embryo growth. Aberrant uterus development is associated with many human reproductive diseases. Among the factors regulating uterus development, vascular remodeling promoters are critical for uterus function and fertility. Vascular endothelial growth factor (VEGF), as one of the major members, has been found to be important in endothelial cell growth and blood vessel development, as well as in non-endothelial cells. VEGF mediation in reproduction has been broadly studied, but VEGF-induced transcriptional machinery during implantation window has not been systematically studied. In this study, a genetically repressed VEGF mouse model was used to analyze uterus transcriptome at gestation 2.5 (G2.5) by Solexa/Illumina's digital gene expression (DGE) system. A number of 831 uterus-specific and 2398 VEGF-regulated genes were identified. Gene ontology (GO) analysis indicated that genes actively involved in uterus development were members of collagen biosynthesis, cell proliferation and cell apoptosis. Uterus-specific genes were enriched in activities of phosphatidyl inositol phosphate kinase, histone H3-K36 demethylation and protein acetylation. Among VEGF-regulated genes, up-regulated were associated with RNA polymerase III activity while down-regulated were strongly related with muscle development. Comparable numbers of antisense transcripts were identified. Expression levels of the antisense transcripts were found tightly correlated with their sense expression levels, an indication of possibly non-specific transcripts generated around the active promoters and enhancers. The antisense transcripts with exceptionally high or low expression levels and the antisense transcripts under VEGF regulation were also identified. These transcripts may be important candidates in regulation of uterus development. This study provides a global survey on genes and antisense transcripts regulated by VEGF in the pre-implantation stage. Results will contribute to further study the candidate genes and pathways in regulating implantation process and related diseases.

Effect of tea polyphenol on oxidative injury in S180 cells induced hepatocarcinoma mice

The purpose of this study was to evaluate the antioxidant nature of tea polyphenol on S180 cells induced liver cancer in mice. In the present study, hepatocellular carcinoma was induced by tumor transplantation of liver in situ. The antitumor activity of tea polyphenol has been determined in vivo in hepatocellular carcinoma mice after treatment of drug (50, 100, 150 mg/kg body weight) by gavage for 20 days. Results showed that a significant increase in serum aspartate transaminase (AST), alkaline phosphatase (ALP), alanine aminotransfere (ALT), malondialdehyde (MDA) level, decrease in serum white blood cells (WBC), serum total protein (TP), albumin (ALB), A/G, tumor necrosis factor-α (TNF-α) and interferon-gamma (IFN-γ), liver reduced glutathione (GSH) levels were observed. In addition, the levels of enzymic and non-enzymic antioxidants were decreased when subjected to S180 cells induction. These altered enzyme levels were ameliorated significantly by administration of tea polyphenol at the concentration of 50, 100, 150 mg/kg body weight in drug-treated animals. These results indicate that the protective effect of tea polyphenol was associated with inhibition of MDA induced by S180 cells and to maintain the antioxidant enzyme levels.

Canine mammary tumours, an overview

Canine mammary tumours (CMTs) are the most common neoplasms in intact female dogs. Although the prevalence of these tumours decreases in regions where preventive ovari(ohyster)ectomy is performed, it remains an important disease entity in veterinary medicine. Moreover, treatment options are limited in comparison with human breast cancer. Nevertheless, recent human treatment protocols might have potential in bitches suffering from CMTs.

Glioma stem/progenitor cells contribute to neovascularization via transdifferentiation

OBJECTIVE

Previous studies suggest that tumor cells might be the progenitor for tumor vasculature. Whether vascular tube formation from transdifferentiation of human glioma stem/progenitor cells (hGSPCs) contribute to angiogenesis of gliomas remain largely uncertain.

METHODS

hGSPCs were isolated from thirteen surgical specimens of gliomas and cultured in medium favored for stem cell growth. In vitro transdifferentiation of hGSPCs was performed under hypoxia. Expression of vascular endothelial cells (VECs) markers CD31, CD34, kinase insert domain receptor (KDR), and von Willebrand factor (vWF) were analyzed with real-time quantitative RT-PCR and immunofluorescence techniques. Vasculogenic mimicry of hGSPCs was evaluated in a tumor stem cell xenograft model in vivo. Relationships between content of hGSPCs and expression levels of both VECs markers and proangiogenic factors in large number of clinical specimens were further investigated in glioma tissue microarray.

RESULTS

In vitro, hGSPCs can transdifferentiate into VECs under hypoxia, they manifested typical "flagstone" pattern when cultivated in medium containing VEGF for a few days; when cultivated on Matrigel they were capable of forming capillary-like structures. Expression of VECs markers including CD31, CD34, KDR, and vWF were significantly up-regulated after transdifferentiation. Human leukocyte antigen (HLA) positively stained vessels were observed inside the xenograft tumors after intracerebral transplantation of hGSPCs in athymic nude mice, implied part of tumor cells with human origin were involved in formation of tumor vessels. In surgical specimens of human glioma, tumor vascular cells coexpressing the markers of early VECs (CD34) and markers of hGSPCs (ABCG2 and nestin) suggest that these vascular cells may stemmed from hGSPCs.

CONCLUSIONS

Our observations suggest the functional role of hGSPCs as endothelial progenitors, which have properties that give rise to VECs, and have the ability to form vascular endothelial tubes. However, unspecific markers (ABCG2, nestin) that stain for both endothelial as well as glioma stem cells, were found to be expressed in tumor vasculature of human specimen, and limit further interpretation of this finding.

Canine classical seminoma: a specific malignant type with human classifications is highly correlated with tumor angiogenesis

Background

Human seminoma is classified as classical seminoma (SE) and spermatocytic seminoma (SS). Human SE is known to be more malignant and metastasizing more frequently than SS. Tumor angiogenesis is highly related with tumor progression and metastasis, with microvessel density (MVD) being an important parameter of metastatic potential. Canine seminoma is not yet well-established as SE or SS type including correlation with angiogenesis. We classified canine SE and SS, and then compared them to tumor associated vessels.

Methods

Twenty-three cases of canine seminomas (2 intratubular, 9 diffuse, and 12 intratubular/diffuse seminomas showing both intratubular and diffuse patterns) were classified as SE or SS by immunohistochemistry (IHC) using monoclonal antibody against PLAP and by PAS stain. The histopathological data were then compared to see if there was a correlation with SE or SS. Angiogenesis of seminomas were evaluated by immunohistochemical assay using polyclonal antibody against Von Willebrand factor (vWF) and by calculating the means of MVD, vessels area and perimeters using computerized image analysis. Statistical Package for Social Sciences (SPSS) program was used for various statistical analyses.

Results

The numbers of PLAP+/PAS+ canine SEs were 8/23 (34.8%) and PLAP-/PAS- SSs were 15/23 (61.2%). All SE cases (8/8, 100%) were intratubular/diffuse types. SS types included 2 intratubular (2/15, 13.3%), 9 diffuse (9/15, 60%), and 4 intratubular/diffuse (4/15, 26.7%) types. MVD and vascular parameters in SEs were significantly higher than in SSs, showing the highest value in the intratubular/diffuse type. Seminomas observed with neoplastic cells invasion of vessels presented higher perimeter and area values than seminomas without conformed neoplastic cells invasion.

Conclusion

In this study, we demonstrated a positive relationship between canine SE and tumor angiogenesis. Furthermore, we also showed that a tumor cells invasion of vessels were a correlated vascular parameter. Although metastasis of canine seminomas has rarely been reported, our results support that canine SE could have high metastatic potential similar to the human counterpart. Further studies are required to clarify the relationship between canine SE and clinical data with metastatic factors.

Effectiveness and safety of bevacizumab for unresectable non-small-cell lung cancer: a meta-analysis

BACKGROUND

Non-small-cell lung cancer (NSCLC) accounts for more than 85% of all cases of lung cancer. The 5-year survival of patients presenting with advanced stage NSCLC is less than 15%, indicating that additional treatment options are needed. Bevacizumab is a recombinant humanized version of the murine anti-human vascular endothelial growth factor (VEGF) monoclonal antibody with a high binding specificity for VEGF.

OBJECTIVE

The aim of this meta-analysis was to evaluate the effectiveness and safety of bevacizumab in patients with unresectable non-small-cell lung cancer (NSCLC) on the basis of evidence-based methodology.

METHODS

The electronic database PubMed was searched to identify randomized, controlled trials (RCTs) of bevacizumab for the treatment of unresectable NSCLC. Other databases such as the Cochrane Library Trials Register, the WHO Trial Registration, the National Cancer Institute, ClinicalTrials.gov, the European Organization for Research and Treatment of Cancer, the Southwest Oncology Group, the Eastern Cooperative Oncology Group, the European Society of Clinical Oncology and the American Society of Clinical Oncology were also searched. The meta-analysis was performed using Reviewer Manager Version 5.0 software provided by the Cochrane Collaboration. Outcome measures were overall survival rates, progression-free survival, tumour response rate, incidence of severe adverse events (SAEs) and treatment-related death.

RESULTS

Four eligible studies that included 2101 patients were found; in these studies, bevacizumab was administered to 1237 patients. Neither high-dose (15 mg/kg) nor low-dose (7.5 mg/kg) bevacizumab increased 1-year overall survival rates compared with patients not treated with bevacizumab. However, high-dose bevacizumab, rather than low-dose, increased 2-year overall survival rate (risk ratio [RR] = 1.24; 95% confidence interval [CI] 1.04, 1.49) and tumour response rate (RR = 1.69; 95% CI 1.21, 2.35) compared with patients not treated with bevacizumab. Progression-free survival was also significantly improved in both the low- (hazard ratio [HR] = 0.76; 95% CI 0.64, 0.90) and high-dose groups (HR = 0.73; 95% CI 0.65, 0.81). There was a clear and significant increase in the rate of treatment-related death in the high-dose group (RR = 2.07; 95% CI 1.19, 3.59) compared with patients not treated with bevacizumab. No significant differences were noted in the rate of treatment-related death in the low-dose group or in the incidences of SAE in the low- or high-dose groups compared with patients not treated with bevacizumab. Neutropenia was easily induced in both the low- and high-dose bevacizumab groups. Patients who received high-dose bevacizumab tended to experience hypertension, neutropenia, haemoptysis, rash and headache more frequently than patients not treated with bevacizumab.

CONCLUSIONS

Low-dose bevacizumab may significantly improve progression-free survival in patients with unresectable NSCLC, whereas high-dose bevacizumab may increase 2-year overall survival rates, prolong progression-free survival and improve tumour response rate but at the cost of higher treatment-related death. Larger well designed RCTs should be carried out in the future to clarify the role of bevacizumab in the treatment of NSCLC.

Eukaryotic expression of extracellular ligand binding domains of murine Tie-2 and its anti-angiogenesis effect in SGC-7901 cell lines

BACKGROUND AND AIMS

Researches about blocking angiogenesis to treat tumor have become one of the most promising and active fields in anticancer research. This study aimed to investigate the eukaryotic expression of extracellular ligand binding domains of murine Tie-2 and its anti-angiogenesis effect.

METHODS

A eukaryotic expression vector pcDNA3.1(+) integrating with a DNA fragment which encode extracellular ligand binding domains of murine Tie-2 was transfected into SGC-7901 gastric cancer cell line. The protein expression was detected by western blot analysis and immunocytochemistry staining. Following the construction of nude mouse tumor xenograft model with and without transfected cells, tumor microvessel density was determined by counting per high power field in the sections stained with an antibody to CD31 to test its inhibition of angiogenesis.

RESULTS

The extracellular ligand binding domains of murine Tie-2 receptor was highly expressed in SGC-7901 gastric cancer cells with plasmid transfection. The mean tumor sizes of groups with and without transfection were 1.27 +/- 0.35 and 1.75 +/- 0.17 cm(3), respectively (P = 0.025). The mean inhibitory rate of tumor was 27.18 +/- 19.93%. The comparison between highest microvessel density of group with transfection (14.00 +/- 3.80) and that of group without transfection (22.30 +/- 5.91) was statistically significant at P = 0.030.

CONCLUSION

The protein of extracellular ligand binding domains of murine Tie-2 can be expressed at high level in the eukaryotic expression system, and the expressed protein may have the anti-angiogenesis effect.

Serum human chorionic gonadotropin is associated with angiogenesis in germ cell testicular tumors

BACKGROUND

Germ cell testicular tumors have survival rate that diminishes with high tumor marker levels, such as human chorionic gonadotropin (hCG). hCG may regulate vascular neoformation through vascular endothelial growth factor (VEGF). Our purpose was to determine the relationship between hCG serum levels, angiogenesis, and VEGF expression in germ cell testicular tumors.

METHODS

We conducted a retrospective study of 101 patients. Serum levels of hCG, alpha-fetoprotein (AFP), and lactate dehydrogenase were measured prior to surgery. Vascular density (VD) and VEGF tissue expression were determined by immunohistochemistry and underwent double-blind analysis.

RESULTS

Histologically, 46% were seminomas and 54%, non-seminomas. Median follow-up was 43 +/- 27 months. Relapse was present in 7.5% and mortality in 11.5%. Factors associated with high VD included non-seminoma type (p = 0.016), AFP > or = 14.7 ng/mL (p = 0.0001), and hCG > or = 25 mIU/mL (p = 0.0001). In multivariate analysis, the only significant VD-associated factor was hCG level (p = 0.04). When hCG levels were stratified, concentrations > or = 25 mIU/mL were related with increased neovascularization (p < 0.0001). VEGF expression was not associated with VD or hCG serum levels.

CONCLUSION

This is the first study that relates increased serum hCG levels with vascularization in testicular germ cell tumors. Hence, its expression might play a role in tumor angiogenesis, independent of VEGF expression, and may explain its association with poor prognosis. hCG might represent a molecular target for therapy.

Classification of tumours

Tumours are classified according to the most differentiated cells with the exception of carcinomas where a few tumour cells show neuroendocrine differentiation. In this case these cells are regarded as redifferentiated tumour cells, and the tumour is not classified as neuroendocrine. However, it is now clear that normal neuroendocrine cells can divide, and that continuous stimulation of such cells results in tumour formation, which during time becomes increasingly malignant. To understand tumourigenesis, it is of utmost importance to recognize the cell of origin of the tumour since knowledge of the growth regulation of that cell may give information about development and thus possible prevention and prophylaxis of the tumour. It may also have implications for the treatment. The successful treatment of gastrointestinal stromal tumours by a tyrosine kinase inhibitor is an example of the importance of a correct cellular classification of a tumour. In the future tumours should not just be classified as for instance adenocarcinomas of an organ, but more precisely as a carcinoma originating from a certain cell type of that organ.

The cytosol activity of thymidine phosphorylase in endometrial cancer

BACKGROUND

Thymidine phosphorylase (TP) is identical with platelet-derived endothelial cell growth factor (PD-ECGF) which promotes angiogenesis. The aim of this study was to evaluate the cytosol activity of TP in tumor samples from patients with endometrial cancer.

METHODS

The activity of TP was measured by the spectrophotometric method in the cytosol of endometrial tumor samples from 43 patients. Moreover, the expression of platelet-derived endothelial cell growth factor/thymidine phosphorylase (PD-ECGF/TP) protein and microvessel density (MD) were examined in the same endometrial tumor samples by immunohistochemical staining. Normal endometrium from 16 women, treated surgically due to nononcological reasons served as a control.A relationship between the cytosol TP activity, PD-ECGF/TP protein expression, MD and clinicopathologic features was investigated.

RESULTS

A significantly higher the cytosol TP activity, PD-ECGF/TP protein expression and MD was stated in malignant tumor samples when compared to the control (samples of normal endometrium). A positive statistically significant correlation between the cytosol enzyme activity and PD-ECGF/TP protein expression and MD was found, but weaker from the remaining ones between PD-ECGF/TP protein expression and MD was observed.Besides no correlation between the cytosol TP activity, PD-ECGF/TP protein expression as well as MD and grading or histopatological type of endometrial cancer was stated.

CONCLUSION

The cytosol TP activity in endometrial cancer is significantly higher than in normal endometrium, with no relation as to the stage and grade of tumors, but correlates with the PD-ECGF/TP protein expression and MD may therefore be associated with favorable prognosis in patients treated with chemo- or radiotherapy after surgery.

Combined effects of treatment with trientine, a copper-chelating agent, and x-irradiation on tumor growth in transplantation model of a murine fibrosarcoma

Combined effects of treatment with trientine, a copper-chelating agent, and X-irradiation on development of fibrosarcoma using a murine transplantation model in vivo and on cellular survival in vitro were examined. Copper contents in the tumors and serum of trientine-treated mice were significantly lower than those of untreated mice. The tumor volumes of mouse fibrosarcoma QRsp-11 cells increased more slowly in the trientine-treated and the X-irradiated mice than in the control mice from 10 to 24 days postinoculation. The extent of inhibition of tumor growth by X-irradiation at 3 Gy was similar to that obtained by treatment with trientine. A combination of trientine and X-irradiation at 3 Gy showed inhibitory effects on tumor growth similar to those obtained by X-irradiation at 6 Gy. The results showed that trientine and X-irradiation interacted additively in inhibition of tumor growth. When QRsp-11 cells and mouse and bovine endothelial cells were treated with trientine after X-irradiation, the surviving fractions of the cells with combined treatments were essentially consistent with the products of the surviving fractions of trientine-treated cells and those of X-irradiated cells. When the cells were pretreated with trientine and X-irradiated, the surviving fractions of the pretreated cells were lower than those of cells without treatment.

Biology of Interactions: Antiepidermal Growth Factor Receptor Agents

Epidermal growth factor receptor (EGFR) signaling inhibition represents a highly promising arena for the application of molecularly targeted cancer therapies. Evolving from several decades of systematic research in cancer cell biology, a series of EGFR inhibitors from both the monoclonal antibody (mAb) and tyrosine kinase inhibitor (TKI) class have been developed and promoted into clinical application. Several EGFR inhibitors have recently gained US Food and Drug Administration approval for cancer therapy in the United States (and many other countries), including the mAbs cetuximab and panitumumab, and the small molecule TKIs gefitinib, erlotinib, and lapatinib. The rapidly expanding preclinical and clinical data contributing to these US Food and Drug Administration drug registrations validates a central role of the EGFR as an important molecular target in epithelial malignancies. In this review, we focus primarily on the biology of EGFR interactions. Through improved understanding of EGFR biology in human cancers, there is anticipation that more tumor-selective therapy approaches with diminished collateral normal tissue toxicity can be advanced. Many questions remain to be answered, particularly with regard to how best combine EGFR inhibitors with conventional cancer therapies, and how to select those patients (tumors) most likely to benefit from EGFR inhibition strategies.

Trientine, a copper-chelating agent, induced apoptosis in murine fibrosarcoma cells in vivo and in vitro

Anti-copper treatments have been investigated to determine whether they suppress angiogenesis and tumor development since Cu is widely accepted as being required for angiogenesis. We examined the effects of treatment with trientine, a copper-chelating agent, on tumor development in a murine xenograft model using fibrosarcoma-derived transplantable QRsp-11 cells and C57BL/6 mice and induction of apoptosis in tumor cells and endothelial cells in vivo and in vitro. The tumor volumes increased more slowly in trientine-treated mice than in untreated mice. Tumor volumes in the treated mice were significantly smaller than those in the untreated mice at 24 days postinoculation (d.p.i.) of tumor cells. A cluster of pyknotic tumor cells and morphological abnormalities in capillary endothelial cells were observed in the tumors of trientine-treated mice but not in the tumors of untreated mice. The proportions of apoptotic and necrotic cells in the tumors of treated mice were approximately 3.5-fold higher than those in the tumors of untreated mice at 14 d.p.i. When the cells were treated with trientine in vitro, mouse endothelial cells and bovine primary endothelial cells showed an approximately 10-fold higher sensitivity to trientine than QRsp-11 cells in terms of D37. However, the proportion of apoptotic cells in endothelial cells was significantly lower than that in QRsp-11 cells after treatment with trientine. These results show that apoptosis was induced in tumor cells by treatment with trientine in vivo and in vitro.

Angiopoietins lack of prognostic significance in ductal mammary carcinoma

Angiopoietins (Ang) have been shown to regulate the process of vasculature and angiogenesis in tumour. Different angiopoietins have different roles during the angiogenic process. The current study sought to examine the levels of the expression of Ang-1, Ang-2, Ang-3 and their receptor Tie-2 in mammary ductal carcinoma and to assess their relevance to prognosis. Fresh frozen ductal carcinoma tissues (n = 90) and adjacent non-cancerous breast tissues (n = 32) were used. The expression of Ang-1, Ang-2 and Ang-3 transcripts in cancer and normal breast tissues were examined quantitatively using quantitative RT-PCR. The protein expression of Ang-1, Ang-2 and Tie-2 was assessed by immunohistochemistry on frozen sectioned tissues.

Ang-1, Ang-2 and Ang-3 were detected in mammary tissues. Ang-1 was seen in both normal epithelial cells, breast cancer cells as well as in endothelial cells. Ang-2 was seen at a higher level than Ang-1 and it is expressed in epithelial, endothelial as well as stromal cells to certain degree. Ang-1 and Ang-2 transcripts were detected almost equally in cancer and normal breast tissue, and Ang-3 was high in cancer tissue compared to normal breast but not significant (155 ± 123 & 24.1 ± 22.6, P > 0.05). No significant differences were seen between patients with different predicted prognosis (using the Nottingham Prognostic Index as a guide) (Ang-1 p = 0.34, Ang-2 p = 0.26 and Ang-3 p = 0.32, respectively). No significant correlation was seen between Ang-1, Ang-2 and Ang-3 with tumour grade. When the levels of the transcripts were compared against clinical outcome (disease free, developed recurrence and patients who died of breast cancer), levels of Ang-3 transcript was found to be high in breast cancer patient who had bone metastasis 33.8 ± 28.3, although the difference was not significant (p = 0.08). No significant difference was seen with levels of Ang-1 and Ang-2 transcripts and clinical outcomes. Furthermore, no significant trend was observed between Tie-2 receptor and clinical/pathological parameters in the cohort.

These data suggest that angiopoietins (Ang-1, Ang-2 and Ang-3) are expressed in mammary tissues, both in normal and tumour. These molecules have limited value in predicting the prognosis and clinical outcome in patients with mammary ductal carcinoma.

Expression of betacellulin and epidermal growth factor receptor in hepatocellular carcinoma: implications for angiogenesis

Hepatocellular carcinoma (HCC) is becoming one of the common malignant tumors worldwide and is characterized by high vascularity. Angiogenesis (formation of new microvessels) is critical for growth and progression of various human solid tumors. Betacellulin (BTC) is a member of the epidermal growth factor (EGF) family, and its signal action is mediated through EGF receptors (EGFR). In this study, to understand the role of BTC in relation to EGFR in HCC, we examined localization, expression, and involvement in angiogenesis of BTC and EGFR. The results revealed that expression of BTC, EGFR, and tumor growth factor-alpha messenger RNA in HCC was increased by 80%, 60%, and 40%, respectively, as compared with those in the nontumorous tissues. Increased expression of BTC protein was observed in 31 (61%) of 51 HCC specimens, and the level of tumor growth factor-alpha protein was higher in 17 (33%) of 51 HCC specimens than in nonmalignant hepatocytes. Betacellulin was predominantly expressed in HCC cells, whereas EGFR was observed in sinusoidal endothelial cells of HCC in 25 tumors (49%). Betacellulin was secreted in all 4 examined HCC cell lines. The HCC specimens showing positive EGFR expression in tumor endothelial cells had a significantly higher microvessel density than those without EGFR expression (P < .005). A strong correlation was found between BTC expression in cancer cells and EGFR expression in tumor endothelial cells (P < .001). These findings suggest that overexpression of BTC by HCC cells and EGFR by tumor endothelial cells enhance vascularity in a paracrine manner.

Role of angiogenesis in inflammatory bowel disease

Several studies have shown alterations in vascular anatomy and physiology in inflammatory bowel disease (IBD). These findings, together with the observed upregulation of the mediators of angiogenesis in IBD patients, suggest that angiogenesis possibly contributes to the initiation and perpetuation of IBD. There is considerable evidence of an interrelationship between the mechanisms of angiogenesis and chronic inflammation in IBD. The increased expression of endothelial junction adhesion molecules found in IBD patients indicates the presence of active angiogenesis. Evidence that angiogenesis is involved in IBD was also obtained from animal models of colitis, most notably from studies of angiogenesis inhibition. Serum levels of vascular endothelial growth factor (VEGF) correlate with disease activity in human IBD and fall with the use of steroids, thalidomide, or infliximab. Pharmacological inhibition of angiogenesis, therefore, has the potential to be a therapeutic strategy in IBD. This review outlines the evidence that the rate of angiogenesis is increased in the inflamed intestine in IBD and proposes lines for future research in this field.

Efectos cutáneos de los inhibidores del receptor del factor de crecimiento epidérmico

Epidermal growth factor receptor (EGFR) inhibitors are a new group of drugs used in the treatment of several malignancies. Three molecules are approved at the moment: gefitinib and erlotinib for the treatment of non-small-cell lung cancer, and cetuximab for colorectal cancer. These drugs originate cutaneous side effects with a high frequency: acneiform rashes, paronychia and generalized xerodermia. In this paper we review these common side effects and how to manage them.

Expression of angiopoietin 1, 2 and their common receptor Tie2 in human gastric carcinoma: implication for angiogenesis

Angiogenesis, formation of new microvessels providing oxygen and nutrient supply, is essential for tumor growth. It is dependent on the production of angiogenic growth factors by tumor cells. Angiopoietin 1 (Ang-1) and 2 (Ang-2) and their common receptor, Tie2, are thought to be critical regulators of tumor angiogenesis. We examined expression of Ang-1, Ang-2, and their common receptor Tie2 mRNAs and proteins in gastric cancers using in situ hybridization and immunohistochemistry. We also investigated the relationship between their expression and differentiation of cancer cells, lymph node metastasis, tumor size, depth of cancer cell invasion, TNM staging and microvessel density (MVD). The expression of Ang-1, Ang-2, and Tie2 mRNA in cancer cells significantly correlated with the MVD (p<0.001, <0.001 and =0.019, respectively). Ang-1 and Tie2 positivity correlated with advanced gastric cancers (p<0.05) and larger cancers had higher positive rates of Ang-1, Ang-2, and Tie2 mRNA expression (p<0.001, =0.010 and =0.039, respectively). Significant positive correlations were also found between mRNA expression of Tie2 and those of Ang-1 and Ang-2 (p<0.01 and <0.001, respectively). These findings indicate that the expression of Ang-1 and Ang-2 is important for tumor angiogenesis, and suggest a possible role of autocrine/paracrine function of angiopoietin/Tie2 system in gastric cancer progression.

Microvessel density does not predict outcome in high grade soft tissue sarcoma

The induction of new blood vessel growth into tumours from a pre-existing vascular bed (angiogenesis) is a characteristic of virtually all malignant tumours studied. Previous studies have demonstrated a consistent correlation between the extent of angiogenesis and disease prognosis for a wide range of carcinomas, but not for sarcomas.

AIMS

To investigate the most appropriate method for assessment of microvessel density (MVD) using a cohort of patients with large (>5 cm), deep (intramuscular), high grade soft tissue sarcoma and investigate any relationship between MVD, vascular endothelial growth factor (VEGF) expression and prognosis.

METHODS

Forty-two patients were included in the study. MVD was evaluated in peripheral, central, necrotic and hotspot areas within the tumour by either Chalkley count or total count of immunostained vessels in five high power (x 200) visual fields.

RESULTS

Hot spots of angiogenesis were only present in 33% of specimens. There was a strong correlation p<0.001 between the two methods of quantification with Chalkey method being recommended. VEGF expression evaluated by immunohistochemistry was seen in all but one tumour with strong diffuse cytoplasmic staining within tumour cells, which was not correlated with microvessel density, metastasis or survival. There was a positive correlation between MVD and histological subtype (p<0.01), and primary tumour size and the development of metastasis (p=0.049) but MVD was not predictive of metastasis or overall survival.

CONCLUSIONS

Unlike the majority of previous studies involving various types of carcinoma, there was no correlation between microvessel density and metastasis or survival in a group of patients with large (>5 cm), deep, high grade soft tissue sarcoma.

Targeting integrins for the control of tumour angiogenesis

The crucial role of cell extracellular matrix communication in angiogenesis is well established; thus, it is not surprising that integrins have gained considerable attention as targets for the treatment of neovascular disease. Given the diversity of ligands and complexity of integrin signalling, a new appreciation for the divergent roles of integrins in angiogenesis is emerging. It is becoming clear that integrins regulate angiogenesis in both a positive and negative manner. New studies have provided a better understanding of integrin structure as it relates to ligand binding and signalling. This new insight has opened exciting possibilities for the design of novel inhibitors for clinical applications. In this review, studies concerning the cooperative interactions between integrins and regulatory molecules and possible new strategies for controlling angiogenesis will be discussed.

Prognostic significance of microvessel density determined by an anti-CD105/endoglin monoclonal antibody in astrocytic tumors: comparison with an anti-CD31 monoclonal antibody

There are conflicting reports as to whether the degree of angiogenesis as measured by microvessel density (MVD) has a prognostic value in astrocytic tumors. This may be due to the use of different antibodies against endothelial cells to highlight microvessels. It has been reported that unlike pan-endothelial antibodies, such as CD31, anti-CD105 antibodies preferentially react with endothelial cells in angiogenic tissues. To clarify the validity of anti-CD105 antibody in the evaluation of angiogenesis, we assessed MVD using an anti-CD105 monoclonal antibody (mAb) (CD105-MVD) and an anti-CD31 mAb (CD31-MVD) in a series of 50 astrocytic tumors, and correlated MVD with expression of the key angiogenic factor vascular endothelial growth factor (VEGF) and prognosis. The mean CD31-MVD and CD105-MVD was 36.7 and 24.8 for low-grade astrocytoma (LGA), 48.0 and 42.7 for anaplastic astrocytoma, 55.3 and 51.9 for glioblastoma multiforme (GBM), respectively. CD105-MVD was more closely correlated with VEGF expression than CD31-MVD. Patients with LGA and GBM showing higher CD105-MVD had a significantly shorter mean survival time (MST) than those with lower CD105-MVD tumors (P = 0.0381 and 0.0131, respectively). Whereas the MST of patients with higher CD31-MVD tumors seemed to be shorter than that of lower CD31-MVD patients within each tumor grade, the differences were not statistically significant. These findings suggest that anti-CD105 mAb may be a better marker than anti-CD31 mAb in evaluation of angiogenesis and prediction of prognosis in astrocytic tumors.

Anti-angiogenic therapies in cancer clinical trials

Strategies involving vasculature have widely been acknowledged to have therapeutic potential in the management of cancer and other diseases. Based on a large body of evidence from preclinical studies and early clinical trials there is considerable optimism that anti-angiogenesis and vascular targeting will be a major clinical therapy. This review considers some 30 anti-angiogenic and vascular targeting agents that are currently in cancer clinical trials and highlights specific problems relating to the assessment of the activity of these agents in patients, trial design, potential toxicities and resistance mechanisms.

Fumagillin treatment of hepatocellular carcinoma in rats: An in vivo study of antiangiogenesis

AIM: To investigate the effect and possible mechanisms of antiangiogenesis therapy for HCC in rats.

METHODS: Adult male LEW/SsN rats were divided into 3 groups, 25 animals each. Group A was the control group. Groups B and C were given diethylnitrosamine, 5 mg/kg/d. In addition, group C rats received an intraperitoneal injection of fumagillin, 30 mg/(kg·d). Five animals in each group were killed at 6^th, 12^th, 18^th, 20^th and 24^th wk to evaluate the development of HCC and metastasis. Weight of the rats, liver tumors, and number of organs involved by HCC were measured at each stage. We compared methionine aminopeptidase-2 (MetAP-2) mRNA, Bcl-2 mRNA, telomerase mRNA, and telomerase activity at 24^th wk in the liver tissue of group A rats and tumor tissue of HCC from group B and C rats.

RESULTS: No HCC developed in group A, but tumors were present in group B and C rats by the 18^th wk. At wk 20 and 24, the median liver weight in group B was 0.64 g (range: 0.58-0.70 g) and 0.79 g (range: 0.70-0.90 g) (P = 0.04), and that in group C was 0.37 g (range: 0.35-0.42 g) and 0.39 g (range: 0.35-0.47 g) (P = 0.67). The liver weight in group C rats was significantly lower than that in group B rats (P = 0.009). At the same time, the median metastasis score (number of organ systems involved) was 3 (range 2-3) in group B, and 1 (range 1-2) in group C, a significant difference between the groups (P = 0.007, 0.004). The levels of MetAP-2 mRNA were significantly higher in groups B and C than in group A (P = 0.025), and significantly higher in group C than in group B (P = 0.047). The level of Bcl-2 mRNA was significantly higher in group B than in group A (P = 0.024), but lower in group C than in group B, although not significantly (P = 0.072). Telomerase mRNA was significantly higher in group B than in group A (P = 0.025), but significantly lower in group C than in group B (P = 0.016). The same inter-group relationship was also true for telomerase activity (P = 0.025 and 0.046).

CONCLUSION: Fumagillin effectively inhibits both liver tumor growth and metastasis in rats in vivo. A possible mechanism is fumagillin-induced inhibition of MetAP-2, which plays an essential role in endothelial cell proliferation. Inhibition of MetAP-2 also results in inhibition of Bcl-2 and telomerase activity.

Clinical significance of the expression of isoform 165 vascular endothelial growth factor mRNA in noncancerous liver remnants of patients with hepatocellular carcinoma

AIM: To investigate the prognostic role of isoform 165 vascular endothelial growth factor messenger RNA (VEGF₁₆₅ mRNA) in noncancerous liver tissues from patients with primary hepatocellular carcinoma (HCC).

METHODS: Using a reverse-transcription polymerase chain reaction (RT-PCR)-based assay, VEGF mRNA was determined prospectively in noncancerous liver tissues from 60 consecutive patients with HCC undergoing curative resection. We categorized the patients with VEGF₁₆₅ mRNA over 0.500 in noncancerous liver tissues as group A, and those below 0.500 as group B.

RESULTS: Among the isoforms of VEGF mRNA by multivariate analysis, a higher level of VEGF₁₆₅ mRNA in noncancerous liver tissue correlated significantly with a higher risk of HCC recurrence (P = 0.039) and recurrence-related mortality (P = 0.048), but VEGF₁₂₁ did not. The other significant predictors of recurrence consisted of vascular permeation (P = 0.022), daughter nodules (P = 0.033), cellular dedifferentiation (P = 0.033), an absent or incomplete capsule (P = 0.037). A significant variable of recurrence-related mortality was vascular permeation (P = 0.012). As to the clinical manifestations of 16 patients who developed recurrence, the recurrent tumor number over 2, recurrent extent over two-liver segments, and the median survival after recurrence, all significantly correlated with group A patients (P = 0.043, 0.043, and 0.048, respectively). However, the presence of extrahepatic metastasis was not (P>0.05). The difference in recurrence after treatment between the two groups had no statistical significance (P>0.05).

CONCLUSION: The higher expression of isoform VEGF₁₆₅ mRNA in noncancerous liver remnant of patients with HCC may be a significant biological indicator of the invasiveness of postoperative recurrence.

Epidermal growth factor receptor in tumor angiogenesis

This article focuses on the preclinical evidence for activation of the epidermal growth factor receptor (EGFR) in promoting angiogenesis and the efficacy of anti-EGFR agents in inhibiting angiogenesis and tumor growth.

Epidermal growth factor receptor as a target to improve treatment of lung cancer

Despite considerable efforts to reduce tobacco use, lung cancer remains the most common cancer in both men and women. Recent advances in radiation therapy and chemotherapy for lung cancer have yielded encouraging results, but survival in patients with locally advanced non-small-cell lung cancer (NSCLC) remains poor. As more and more molecular changes and their importance in malignant tissues continue to be characterized, approaches to target those aberrant pathways are being actively explored. The epidermal growth factor receptor (EGFR) is commonly overexpressed in NSCLC, particularly squamous cell carcinoma, and has been implicated in the development and progression of this disease, although a clear correlation with prognosis has not been established. Several different strategies have been developed to target and block the EGFR and its downstream effects, and some of them have been intensively studied in preclinical and clinical studies as a single-agent approach or in combination with radiation therapy or chemotherapy. In this article, we review the role of EGFR in lung cancer, as well as preclinical and clinical data on strategies to interfere with EGFR signaling alone or in combination with chemotherapy, radiation, or both.