Combined analysis of vascular endothelial growth factor and platelet-derived endothelial cell growth factor expression in gastric carcinoma

Genetic polymorphisms of vascular endothelial growth factor (VEGF) associated with gastric cancer recurrence after curative resection with adjuvant chemotherapy

Background

The relationship between polymorphisms in vascular endothelial growth factor (VEGF) and gastric cancer is still inconclusive. We investigated whether there is an association between VEGF genetic polymorphisms and risk of gastric cancer, and evaluated the recurrence of advanced gastric cancer after curative resection with adjuvant chemotherapy according to VEGF genetic polymorphisms.

Methods

The association of functional single nucleotide polymorphisms (SNPs) of the VEGF gene (+936C > T, − 634G > C, − 2578C > A, + 1612G > A) were evaluated. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. A total of 151 patients with gastric cancer were enrolled, and the control group consisted of 413 individuals with esophago-gastroduodenoscopy who were randomly selected through health screening. All of the enrolled patients had curative resections with completion of adjuvant capecitabine and oxaliplatin combination chemotherapy and the initial metastatic cases were excluded. During the regular follow-up protocol, the episodes of the recurrence were documented and the specific genotype and allelic frequencies were evaluated.

Results

As for the cancer risk, there were no significant differences in specific genotypes and allelic frequencies. The mean follow-up period was 28.82 ± 30.92 (12 ~ 72) months and the recurrence rate was 28.3%. In the patients carrying the 936-C allele, the recurrence rate of gastric cancer was high (P = 0.02). Disease-free interval was significantly different between the patients carrying the 936-CC and 936-CT/TT genotype (P = 0.02).

Conclusions

VEGF 936-C allele is associated with poor prognosis, but not risk of gastric cancer. In the patients carrying the 936-C allele, more potent adjuvant treatment would be considered.

Thymidine phosphorylase affects clinical outcome following surgery and mRNA expression levels of four key enzymes for 5-fluorouracil metabolism in patients with stage I and II non-small cell lung cancer

The expression levels of thymidine phosphorylase (TP), dihydropyrimidine dehydrogenase (DPD), thymidylate synthase (TS) and orotate phosphoribosyltransferase (OPRT) may predict the clinical efficacy of 5-fluorouracil-based chemotherapy in patients with cancer. We herein investigated the differences in the mRNA levels of these enzymes in non-small-cell lung cancer (NSCLC) and evaluated their prognostic value for NSCLC treated by surgical resection. The intratumoral mRNA levels of TP, DPD, TS, and OPRT were quantified in 66 patients with pathological stage I and II NSCLC (adenocarcinoma or squamous cell carcinoma) following complete resection according to the Danenberg Tumor Profile method. The TP level was the only significant prognostic factor for disease-specific survival (DSS) following complete resection; the mean TP mRNA level differed significantly between the high and low mRNA expression groups. The DSS at 5 years was significantly higher in the low TP mRNA compared with that in the high TP mRNA expression group (83.4 vs. 58.6%, respectively; P=0.005). A Cox proportional hazards model revealed that pathological stage, sex, and TP expression were independent prognostic factors for DSS in patients with stage I and II NSCLC following complete resection. Thus, TP level may be used to monitor treatment efficacy and predict the outcome of NSCLC patients.

Predictive Significance of Serum Level of Vascular Endothelial Growth Factor in Gastric Cancer Patients

The study aims to evaluate serum VEGF expression in gastric cancer patients and investigate its relationship with clinicopathological parameters. We also examined the serum VEGF levels in GC patients having received surgery or chemotherapy treatment to assess its predictive and prognostic value as a biomarker. We enrolled 154 GC patients having not received neoadjuvant treatment and 100 healthy controls. In the treatment groups, 13 surgery patients and 15 chemotherapy patients were investigated. 42 chemotherapy patients with different chemotherapy efficacy were recruited as well. The serum VEGF was examined by ELISA. Serum VEGF level was remarkably upregulated in GC group compared with healthy group (p < 0.001). The serum VEGF level of GC group was significantly correlated with tumor cells differentiation degree, clinical stages, tumor infiltration depth, lymph node metastasis, and tumor size. The serum VEGF level of the 1 to 3 days after operation group was much lower than that of the preoperative group (p < 0.001) and the 7 days after operation group (p < 0.001). By contrast, serum VEGF level was decreased significantly after chemotherapy (p = 0.001). Importantly, serum VEGF level in PD+SD group was significantly higher compared to the PR+CR group (p = 0.011). Therefore, serum VEGF was a valuable biomarker in clinically monitoring the condition of GC patients.

Angiogenesis inhibitors in gastric and gastroesophageal junction cancer

Despite significant improvements in systemic chemotherapy during the past two decades, the prognosis of patients with advanced gastric and gastroesophageal junction adenocarcinoma remains poor. Because of molecular heterogeneity, it is essential to classify tumors based on the underlying oncogenic pathways and to develop targeted therapies acting on individual tumors. Unfortunately, although a number of molecular targets have been studied, very few of these agents can be used in a clinical setting. In this review, we summarize the available data on anti-angiogenic agents in advanced/metastatic gastric cancer.

Monoclonal antibodies-based treatment in gastric cancer: current status and future perspectives

Gastric cancer (GC) is the second leading cause of cancer-related death, and despite having improved treatment modalities over the last decade, for most patients, only modest improvements have been seen in overall survival. Recent progress in understanding the molecular biology of GC and the related signaling pathways offers, from the clinical point of view, promising advances for selected groups of patients. In the past, targeted therapies have significantly impacted the treatment strategy of several common solid tumors such as breast, colorectal, and lung cancers. Unfortunately, translational and clinical research shows fewer encouraging targeted treatments with regards to the GC. To date, only two monoclonal antibodies (mAb), named trastuzumab and ramucirumab, are approved for the treatment of advanced GC, suggesting that in GC, maybe more than in other cancers, effective targeted therapy requires patient selection based on precise predictive molecular biomarkers. The aim of this review is to summarize the available data on the clinical advantages offered by the use of mAbs in the treatment of advanced/metastatic GC. Future perspective is also discussed.

Comparison of site-specific gene expression levels in primary tumors and synchronous lymph node metastases in advanced gastric cancer

BACKGROUND

Many malignant tumors consist of heterogeneous subpopulations of cells. This heterogeneity is associated with genetic characteristics. However, it remains unclear whether gene expression levels differ among specific sites of tumors in gastric cancer.

METHODS

We studied differences in gene expression levels among specific sites of primary tumors and synchronous lymph node metastases, using formalin-fixed, paraffin-embedded specimens resected surgically from 48 patients with previously untreated advanced gastric cancer. Specimens were obtained by laser-captured microdissection from five regions: (1) nonneoplastic mucosa, (2) surface layer (mucosa) of the primary tumor (surface sections), (3) middle layer (submucosa) of the primary tumor (middle sections), (4) the deepest layer of the primary tumor (muscularis propria or deeper) at the site of deepest invasion (deep sections), and (5) level 1 synchronous lymph node metastasis (lymph node metastases). Expression levels of the following target genes were determined by quantitative real-time polymerase chain reaction: thymidylate synthase (TS), thymidine phosphorylase (TP), dihydropyrimidine dehydrogenase (DPD), epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), and hypoxia-inducible factor-1α (HIF1α).

RESULTS

TP, DPD, EGFR, and HIF1α gene expression levels were significantly higher in deep sections than in surface sections. TP, EGFR, VEGF, and HIF1α gene expression levels were significantly higher in lymph node metastases than in surface sections. TP, DPD, EGFR, VEGF, and HIF1α gene expression levels were positively correlated with the specific samples harvested from the tumors.

CONCLUSIONS

Our results show that the expression levels of some genes in tumor cells can change in specific sites of tumors and can become higher in association with tumor progression.

Anti-angiogenic therapies for advanced esophago-gastric cancer

Neo-vascularization is a vital process for tumor growth and development which involves the interaction between tumor cells and stromal endothelial cells through several growth factors and membranous receptors which ultimately activate pro-angiogenic intracellular signaling pathways. Inhibition of angiogenesis has become a standard treatment option for several tumor types including colorectal cancer, glioblastoma and ovarian cancer. In gastric cancer, the therapeutic role of anti-angiogenic agents is more controversial. Bevacizumab and ramucirumab, two monoclonal antibodies, which target vascular endothelial growth factor-A and vascular endothelial growth factor receptor-2, respectively, have been demonstrated antitumor activity in patients with tumors of the stomach or esophagogastric junction. However, especially for bevacizumab, this antitumor activity has not consistently translated into a survival advantage over standard treatment in randomized trials. In this article, we provide an overview of the role of angiogenesis in gastric cancer and discuss the results of clinical trials that investigated safety and effectiveness of antiangiogenic therapies in this disease. A review of the literature has been done using PubMed, ClinicalTrials.gov website and the ASCO Annual Meeting Library.

Prognostic value of vascular endothelial growth factor expression in resected gastric cancer

BACKGROUND AND AIMS

Vascular endothelial growth factor (VEGF) is a potential prognostic biomarker for patients with resected gastric cancer. However, its role remains controversial. The objective of this study was to conduct a systematic review and meta-analysis of published literature.

METHODS

Relevant literature was identified using Medline and survival data from published studies were collected following a methodological assessment. Quality assessment of eligible studies and meta-analysis of hazard ratio (HR) were performed to review the correlation of VEGF overexpression with survival and recurrence in patients with gastric cancer.

RESULTS

Our meta-analysis included 44 published studies with 4,794 resected patients. VEGF subtype for the prediction of overall survival (OS) included tissue VEGF (HR=2.13, 95% CI 1.71-2.65), circulating VEGF (HR=4.22, 95% CI 2.47-7.18), tissue VEGF-C (HR=2.21, 95% CI 1.58-3.09), tissue VEGF-D (HR=1.73, 95% CI 1.25-2.40). Subgroup analysis showed that HRs of tissue VEGF for OS were, 1.78 (95% CI 0.90-3.51) and 2.31 (95% CI 1.82-2.93) in non-Asians and Asians, respectively. The meta-analysis was also conducted for disease free survival (DFS) and disease specific survival (DSS).

CONCLUSION

Positive expression of tissue VEGF, circulating VEGF, VEGF-C and VEGF-D were all associated with poor prognosis in resected gastric cancer. However, VEGF demonstrated no significant prognostic value for non-Asian populations. Circulating VEGF may be better than tissue VEGF in predicting prognosis.

Long-term follow-up of immunocytochemical analysis of vascular endothelial growth factor (VEGF), and its two receptors, VEGF-R1 (Flt-1) and VEGF-R2 (Flk-1/KDR), in oesophagogastric cancer

BACKGROUND

The prognostic significance of immunocytochemical analysis of tumour vascular endothelial growth factor (VEGF) and its 2 receptors, VEGF-R1 and VEGF-R2, remains incompletely investigated in patients with oesophagogastric cancer.


METHODS

Patients undergoing surgical resection were prospectively recruited between February 1999 and August 2000. Immunocytochemical analysis of VEGF, VEGF-R1 (Flt-1) and VEGF-R2 (Flk-1/KDR) was undertaken using validated techniques. Patients were followed up over a 10-year period using the Northern Ireland Cancer Registry.


RESULTS

Sixty-one patients were recruited (male=45, 73.8%) with a median age of 66.0 years (range 39-83). Forty-seven (77.0%) adenocarcinomas and 14 (23.0%) squamous cell carcinomas were resected. UICC tumour staging was: stage I=14.7%, II=24.6%, III=54.1% and IV=6.6%. VEGF, VEGF-R1 and VEGF-R2 were over-expressed in tumour epithelial cells. VEGF-R2 expression was decreased in the presence of lymphovascular invasion and higher tumour grade. The 10-year survival rate was 19.7% (n=12) with a median follow-up of 808 (IQR 356-2313) days. On univariate analysis only lymphovascular invasion significantly predicted poor prognosis in this cohort (p=0.05). 


CONCLUSION

VEGF, VEGF-R1 and VEGF-R2 were over-expressed in tumour epithelial cells. VEGF-R2 expression was decreased in the presence of more aggressive pathological variables. Larger studies are required to assess the prognostic significance of these biomarkers in oesophagogastric cancer.

Prognostic impact of vascular endothelial growth factor-A expression in resected gallbladder carcinoma

The purpose of this study was to evaluate the value of vascular endothelial growth factor-A (VEGF-A) expression and other confirmed prognostic factors in predicting clinical outcomes after the resection of gallbladder carcinoma (GBC). Between January 1999 and January 2006, a total of 84 consecutive and non-selected patients who underwent resection for GBC were retrospectively reviewed. Of the 84 patients studied, 45 cases (53.6%) exhibited high expression of VEGF-A and were placed into the high expression group. The 14 cases (16.7%) that showed no VEGF expression and the 25 cases (29.7%) that had lower VEGF-A levels were pooled into the low expression group (46.4%). There was a relationship between VEGF-A status and pM stage (P = 0.027) as well as histologic differentiation (P < 0.001). In univariate analysis by log-rank test, ECOG performance status, CA 19-9, pN stage, pM stage, histologic differentiation, and VEGF-A expression were significant prognostic factors (P = 0.015, 0.001, 0.020, <0.001, 0.040, and <0.001, respectively). Multivariate analysis revealed that pN status and VEGF-A expression maintained independent prognostic influence on overall survival (P < 0.001 and P = 0.013, respectively). VEGF-A expression has a positive correlation with pM stage and histologic differentiation. pN status and VEGF-A expression were independent prognostic factors of overall survival in patients with resected GBC.

Growth factor mediated signaling in pancreatic pathogenesis

Functionally, the pancreas consists of two types of tissues: exocrine and endocrine. Exocrine pancreatic disorders mainly involve acute and chronic pancreatitis. Acute pancreatitis typically is benign, while chronic pancreatitis is considered a risk factor for developing pancreatic cancer. Pancreatic carcinoma is the fourth leading cause of cancer related deaths worldwide. Most pancreatic cancers develop in the exocrine tissues. Endocrine pancreatic tumors are more uncommon, and typically are less aggressive than exocrine tumors. However, the endocrine pancreatic disorder, diabetes, is a dominant cause of morbidity and mortality. Importantly, different growth factors and their receptors play critical roles in pancreatic pathogenesis. Hence, an improved understanding of how various growth factors affect pancreatitis and pancreatic carcinoma is necessary to determine appropriate treatment. This chapter describes the role of different growth factors such as vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF), platelet derived growth factor (PDGF), fibroblast growth factor (FGF), epidermal growth factor (EGF), and transforming growth factor (TGF) in various pancreatic pathophysiologies. Finally, the crosstalk between different growth factor axes and their respective signaling mechanisms, which are involved in pancreatitis and pancreatic carcinoma, are also discussed.

Prognostic impact of vascular endothelial growth factor-A and E-cadherin expression in completely resected pathologic stage I non-small cell lung cancer

OBJECTIVE

The purpose of this study was to evaluate the value of vascular endothelial growth factor-A and E-cadherin expression as well as other confirmed prognostic factors in predicting the clinical outcome after definitive surgery of pathologic stage I non-small cell lung cancer.

METHODS

One hundred and eighty-five consecutive and non-selected patients who underwent definitive surgery for stage I non-small cell lung cancer in our institute were included in this study. Formalin-fixed paraffin-embedded specimens were stained for vascular endothelial growth factor-A and E-cadherin and the correlation between the staining, its clinicopathological parameters and its prognostic power were analyzed statistically.

RESULTS

Of the 185 patients studied, 92 cases (49.7%) were strongly positive for vascular endothelial growth factor-A. Vascular endothelial growth factor-A expression was only related to visceral pleural involvement (P < 0.001). A total of 95 carcinomas (51.4%) were E-cadherin-negative tumors. E-cadherin expression correlated with histology (P < 0.001), tumor size (P = 0.001) and visceral pleural involvement (P < 0.001). In univariate analysis by log-rank test, gender, tumor size, lymphovascular invasion, visceral pleural involvement, vascular endothelial growth factor-A expression and E-cadherin expression were significant prognostic factors (P = 0.003, 0.042, 0.026, 0.035, 0.008 and 0.006, respectively). In multivariate analysis, gender, vascular endothelial growth factor-A and E-cadherin expression maintained its independent prognostic influence on overall survival (P = 0.013, <0.001 and 0.036, respectively).

CONCLUSIONS

Expression of vascular endothelial growth factor-A is related to visceral pleural involvement, and E-cadherin expression correlates with histology, tumor size and visceral pleural involvement. Multivariate analysis confirmed gender, vascular endothelial growth factor-A and E-cadherin expression were significant predictive factors for overall survival in completely resected pathologic stage I non-small cell lung cancer.

Design, synthesis and enzymatic evaluation of 6-bridged imidazolyluracil derivatives as inhibitors of human thymidine phosphorylase

A series of novel imidazolyluracil conjugates were rationally designed and synthesised to probe the active site constraints of the angiogenic enzyme, thymidine phosphorylase (TP, E.C. 2.4.2.4). The lead compound in the series, 15d, showed good binding in the active site of human TP with an inhibition in the low μM range. The absence of a methylene bridge between the uracil and the imidazolyl sub-units (series 16) decreased potency (up to 3-fold). Modelling suggested that active site residues Arg202, Ser217 and His116 are important for inhibitor binding.

The dual role of thymidine phosphorylase in cancer development and chemotherapy

Thymidine phosphorylase (TP), also known as "platelet-derived endothelial cell growth factor" (PD-ECGF), is an enzyme, which is upregulated in a wide variety of solid tumors including breast and colorectal cancers. TP promotes tumor growth and metastasis by preventing apoptosis and inducing angiogenesis. Elevated levels of TP are associated with tumor aggressiveness and poor prognosis. Therefore, TP inhibitors are synthesized in an attempt to prevent tumor angiogenesis and metastasis. TP is also indispensable for the activation of the extensively used 5-fluorouracil prodrug capecitabine, which is clinically used for the treatment of colon and breast cancer. Clinical trials that combine capecitabine with TP-inducing therapies (such as taxanes or radiotherapy) suggest that increasing TP expression is an adequate strategy to enhance the antitumoral efficacy of capecitabine. Thus, TP plays a dual role in cancer development and therapy: on the one hand, TP inhibitors can abrogate the tumorigenic and metastatic properties of TP; on the other, TP activity is necessary for the activation of several chemotherapeutic drugs. This duality illustrates the complexity of the role of TP in tumor progression and in the clinical response to fluoropyrimidine-based chemotherapy.

Structures of native human thymidine phosphorylase and in complex with 5-iodouracil

Thymidine phosphorylase (TP) first identified as platelet derived endothelial cell growth factor (PD-ECGF) plays a key role in nucleoside metabolism. Human TP (hTP) is implicated in angiogenesis and is overexpressed in several solid tumors. Here, we report the crystal structures of recombinant hTP and its complex with a substrate 5-iodouracil (5IUR) at 3.0 and 2.5A, respectively. In addition, we provide information on the role of specific residues in the enzymatic activity of hTP through mutagenesis and kinetic studies.

Angiogenic factor thymidine phosphorylase increases cancer cell invasion activity in patients with gastric adenocarcinoma

We investigated the biological role of thymidine phosphorylase (TP), an angiogenic factor, in gastric cancer cell migration and invasion and explored a therapeutic approach for high TP-expressing tumors using TP enzymatic inhibitor (TPI) and rapamycin. We established TP cDNA overexpressing gastric cancer cell lines (MKN-45/TP and YCC-3/TP) and did invasion and adhesion assays with Matrigel-coated transwell membranes. The related signal pathway using recombinant human TP (rhTP), deoxy-d-ribose (D-dRib), and signal pathway inhibitors (wortmannin, LY294002, and rapamycin) was investigated. First, AGS and MKN-1 gastric cancer cell lines showed dose-dependent up-regulation of invasiveness through Matrigel following treatment with rhTP or D-dRib. TP-overexpressing cancer cell lines displayed increased migration and invasion activity, which doubled with rhTP and D-dRib treatment. This activity depended on the enzymatic activity of TP, and TP stimulated the adhesion of cancer cells onto Matrigel and induced actin filament remodeling. Finally, we showed that this activity is related to increased phosphatidylinositol 3-kinase activity in TP-overexpressing cells and that combination treatment with rapamycin and TP enzymatic inhibitor produces an additive effect to abrogate TP-induced invasion. Taken together, TP increases the migration and invasion of gastric cancer cells, especially in TP-expressing cells. Therapies targeting TP might diminish the propensity for invasion and metastasis in gastric cancer.

Efficacy of laser capture microdissection plus RT-PCR technique in analyzing gene expression levels in human gastric cancer and colon cancer

Background

Thymidylate synthase, dihydropyrimidine dehydrogenase, thymidine phosphorylase, and orotate phosphoribosyltransferase gene expressions are reported to be valid predictive markers for 5-fluorouracil sensitivity to gastrointestinal cancer. For more reliable predictability, their expressions in cancer cells and stromal cells in the cancerous tissue (cancerous stroma) have been separately investigated using laser capture microdissection.

Methods

Thymidylate synthase, dihydropyrimidine dehydrogenase, thymidine phosphorylase, and orotate phosphoribosyltransferase mRNA in cancer cells and cancerous stroma from samples of 47 gastric and 43 colon cancers were separately quantified by reverse transcription polymerase chain reaction after laser capture microdissection.

Results

In both gastric and colon cancers, thymidylate synthase and orotate phosphoribosyltransferase mRNA expressions were higher (p < 0.0001, p <0.0001 respectively in gastric cancer and P = 0.0002, p < 0.0001 respectively in colon cancer) and dihydropyrimidine dehydrogenase mRNA expressions were lower in cancer cells than in cancerous stroma (P = 0.0136 in gastric cancer and p < 0.0001 in colon cancer). In contrast, thymidine phosphorylase mRNA was higher in cancer cells than in cancerous stroma in gastric cancer (p < 0.0001) and lower in cancer cells than in cancerous stroma in colon cancer (P = 0.0055).

Conclusion

By using this method, we could estimate gene expressions separately in cancer cells and stromal cells from colon and gastric cancers, in spite of the amount of stromal tissue. Our method is thought to be useful for accurately evaluating intratumoral gene expressions.

Interleukin-1alpha enhances angiogenesis and is associated with liver metastatic potential in human gastric cancer cell lines

BACKGROUND

To better understand the underlying mechanism of liver metastasis formation in human gastric cancer, we evaluated the angiogenic capabilities of human gastric cancer cell lines with different metastatic potentials as well as the role of interleukin (IL)-1alpha in the angiogenic process.

MATERIALS AND METHODS

Reverse transcription-polymerase chain reaction was used to detect the expression of IL-1alpha and vascular endothelial growth factor (VEGF) mRNA in gastric cancer cell lines with different liver metastatic potentials. Levels of VEGF secreted by human gastric cancer cells were measured by enzyme-linked immunosorbent assay. We also examined how gastric cancer cells with different metastatic potentials influence the proliferation and tube formation of human umbilical vein endothelial cells (HUVECs) using the Premix WST-1 cell proliferation assay system and an angiogenesis assay, respectively.

RESULTS

IL-1alpha expression levels were significantly correlated with liver metastatic potential in gastric cancer cell lines. Levels of VEGF secreted by gastric cancer cells appear to be regulated by IL-1alpha through IL-1 receptor Type 1 and were correlated with liver metastatic potential. Both HUVEC proliferation and tube formation were strongly enhanced by coculture with high liver-metastatic gastric cancer cells and were enhanced to a similar extent by culture in the presence of IL-1alpha. In contrast, blockade of IL-1alpha inhibited both HUVEC proliferation and angiogenesis.

CONCLUSIONS

IL-1alpha may play a role in liver metastasis of gastric cancer via enhanced vascular endothelial cell proliferation and angiogenesis.

Gliostatin/thymidine phosphorylase-regulated vascular endothelial growth-factor production in human fibroblast-like synoviocytes

Gliostatin/thymidine phosphorylase (GLS/TP) is known to have angiogenic and arthritogenic activities. The purpose of this study was to elucidate whether GLS/TP is involved in the regulation of the angiogenic cytokine vascular endothelial growth factor (VEGF) in rheumatoid arthritis (RA). Fibroblast-like synoviocytes (FLSs) from patients with RA were cultured and stimulated with recombinant human GLS (rHuGLS) and interleukin (IL)-1beta. Immunohistochemistry showed that GLS/TP and VEGF were detectable in the synovial lining cells. In cultured FLSs, both VEGF mRNA and protein levels were markedly increased by rHuIL-1beta treatment. rHuGLS increased VEGF mRNA expression in a dose-dependent manner. We detected high concentrations of VEGF165 protein in culture supernatants from FLSs treated with rHuGLS (300 ng/ml), which were comparable to GLS levels found in synovial fluid of RA patients. These findings indicate that GLS/TP and VEGF have synergistic effects on angiogenesis in rheumatoid synovitis, and that GLS/TP has a role in regulating VEGF.

Genomic instability and tissue expression of angiogenic growth factors in sporadic colorectal cancer

BACKGROUND

Chromosomal instability evidenced by a loss of heterozygosity (LOH) is implicated as a predictor of poor survival in patients with colorectal cancer, whereas microsatellite instability (MSI) is associated with improved survival rates. We investigated the relationship between tumor expression of angiogenic growth factors and genomic alterations in colorectal cancer.

METHODS

Two genotypes, LOH and MSI, determined by microsatellite markers in the 4 cancer-related chromosomes 2p, 3p, 17p, and 18q, were analyzed in 73 patients with colorectal cancer. The tumor-specific expression of vascular endothelial growth factor and hepatocyte growth factor (HGF) were quantified, and the interleukin-6 network also was evaluated.

RESULTS

MSI-positive neoplasms showed a lesser expression of both tumor growth factors and interleukin-6. In contrast, LOH-positive neoplasms showed a greater expression of HGF and a lesser expression of interleukin-1-receptor antagonist. MSI neoplasms were correlated with favorable prognosis in agreement with previous findings.

CONCLUSIONS

The suppressed production of angiogenic growth factors in MSI cancers partly might explain the better prognosis in MSI-positive patients. The interleukin-6 network, which upregulates production of vascular endothelial growth factor and HGF, might be involved in this mechanism.

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.

The inhibitory effect of disease-modifying anti-rheumatic drugs and steroids on gliostatin/platelet-derived endothelial cell growth factor production in human fibroblast-like synoviocytes

Gliostatin/platelet-derived endothelial cell growth factor (GLS/PD-ECGF) is known to have both angiogenic and arthritogenic activities. The purpose of this study was to investigate whether disease-modifying anti-rheumatic drugs (DMARDs) and steroids are involved in the regulation of GLS expression. Fibroblast-like synoviocytes (FLSs) obtained from patients with rheumatoid arthritis (RA) were cultured and stimulated by interleukin (IL)-1beta with or without DMARDs and steroids. The expression levels of GLS were determined using the reverse transcription-polymerase chain reaction and an ELISA. In cultured rheumatoid FLSs, the expression of GLS mRNA was significantly increased by stimulation with IL-1beta. By contrast, GLS mRNA levels in IL-1beta-stimulated FLSs were reduced by treatment with aurothioglucose (AuTG) and dexamethasone (DEX). These findings indicate that AuTG and DEX have anti-rheumatic activity, which is mediated via the suppression of GLS production. Neither methotrexate (MTX) nor sulfasalazine (SSZ) had a significant influence on GLS levels in our study.

Usefulness of plasma vascular endothelial growth factor in the diagnosis of pancreatic carcinoma: differential diagnosis, tumor progression, and patient survival

OBJECTIVES

This study aimed to examine the usefulness of plasma vascular endothelial growth factor (p-VEGF) in patients with pancreatic carcinoma (PC) as a tumor marker for PC in comparison with chronic pancreatitis (CP) and to clarify the relationship between p-VEGF and the clinicopathological features of PC.

METHODS

The subjects were 69 patients with PC, 35 with CP, and 26 healthy volunteers (control group). The p-VEGF levels were measured by enzyme-linked immunoassay.

RESULTS

p-VEGF levels were significantly higher in the PC group compared with the CP and control groups (P < 0.0001). A cut-off level of 149.5 pg/mL, discriminating between PC and CP, was determined based on a receiver operating characteristic curve. Using this cut-off level, the sensitivity was 60%, specificity was 96%, and accuracy was 73%. Patients with PC with distant metastases exhibited a significantly higher level of p-VEGF compared with those without metastasis (P = 0.0113). Multivariate analysis indicated that a high level of p-VEGF was an independent prognostic factor, and a significant association was observed between p-VEGF and median survival time (P = 0.0092).

CONCLUSIONS

p-VEGF proved useful in differentiating between PC and CP, and in patients with PC, a high level of p-VEGF may be a predictor of distant metastases and poor prognosis.

Immunohistochemical assessment of angiogenesis in hepatocellular carcinoma and surrounding cirrhotic liver tissues

AIM: To investigate whether vascular endothelial growth factor (VEGF) was over-expressed in hepatocellular carcinoma (HCC) or in surrounding cirrhotic liver tissues.

METHODS: Immunohistochemistry was performed to investigate the expression of VEGF proteins in HCC tissues from 105 consecutive patients undergoing curative resection for HCC. The immunostaining results and related clinicopathologic materials were analyzed with statistical methods. Kaplan–Meier method was used to calculate survival curves, and Log-rank test was performed to compare differences in survival rates of the patients with positive HCC staining and negative VEGF.

RESULTS: VEGF-positive expression was found in 72 of 105 HCC patients (68.6%). Capsular infiltration (P = 0.005), vascular invasion (P = 0.035) and intrahepatic metastasis (P = 0.008) were observed more frequently in patients with VEGF-positive expression than in those with VEGF-negative expression. Kaplan–Meier curves showed that VEGF-positive expression was associated with a shorter overall survival (P = 0.014). VEGF-positive expression was found in 47 of tissues 68 HCC (69.1%), and VEGF-positive expression was found in 54 of 68 surrounding cirrhotic liver tissues (79.4%). VEGF-positive expression was significantly higher in surrounding cirrhotic liver tissues than in HCC (P = 0.017).

CONCLUSION: VEGF may play an important role in the angiogenesis and prognosis of HCC, as well as in the angiogenesis of liver cirrhosis.

Regulation of vascular endothelial growth factor expression in human gastric cancer cells by interleukin-1beta

BACKGROUND

Vascular endothelial growth factor (VEGF), a dominant angiogenic factor in gastric cancer, is upregulated by cytokines in the tumor microenvironment. Interleukin-1beta (IL-1beta), a proinflammatory cytokine, has been shown to be proangiogenic in vivo, despite its not demonstrating angiogenic activity in vitro. We hypothesized that IL-1beta regulates VEGF expression in human gastric cancer cells and investigated the mechanism by which this occurs.

METHODS

We treated the TMK-1 human gastric cancer cell line with IL-1beta for 1 to 24 hours, and then analyzed VEGF mRNA expression by Northern blotting and signaling intermediates by Western blotting. Signaling inhibitors were used to identify the dominant pathways involved in IL-1beta induction of VEGF. VEGF promoter-luciferase constructs and transcription blockers were used to investigate the transcriptional regulation of VEGF by IL-1beta.

RESULTS

Treating TMK-1 cells with IL-1beta increased VEGF mRNA levels and activated extracellular signal-regulated kinases 1 and 2 (Erk 1/2) and p38, but not Akt. Inhibitors of the Erk and p38 pathways blocked IL-1beta induction of VEGF mRNA. Treating TMK-1 cells with IL-1beta also increased VEGF promoter activity. VEGF transcriptional activity was found to depend on a 120-bp region just proximal to the transcription start site.

CONCLUSIONS

In human gastric cancer cells, IL-1beta induced VEGF through Erk- and p38-dependent pathways; this induction of VEGF was transcriptionally regulated.

Expression of the angopoietin-1, angopoietin-2, Tie2, and vascular endothelial growth factor gene in epithelial ovarian cancer

OBJECTIVES

Angiopoietin/Tie2 system with vascular endothelial growth factor (VEFG) is known to be important for the initiation of angiogenesis in tumors. The aim was to evaluate whether angiopoietin/Tie2 system with VEFG affects prognosis in patients of epithelial ovarian cancer.

METHODS

Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2), Tie2, and VEGF gene expression were analyzed by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) in 85 epithelial ovarian cancer surgical specimens. These gene expressions were correlated with clinical-pathological parameters, microvessel density (MVD), and patients' survival.

RESULTS

Ang-1/Ang-2 gene expression ratio, VEGF, and Tie2 gene expression significantly associated with MVD, respectively (P < 0.0001, P = 0.024, P = 0.005). The patients with low Ang-1/Ang-2 gene expression ratio and high VEGF gene expression were found to have a significantly higher MVD when compared to others (P = 0.0003). Moreover, there was a significant difference between the values of MVD in patients with low Ang-1/Ang-2 gene expression ratio and high VEGF and high Tie2 gene expression and those in others (P = 0.0025). FIGO stage (P = 0.014), residual disease (P = 0.042), histological grade (P = 0.028), Ang-1/Ang-2 gene expression ratio (P = 0.010), and combination of Ang-1/Ang-2 gene expression ratio and VEGF gene expression (P = 0.019), were found to be significantly associated with a poor prognosis in univariate Cox regression analysis. Multivariate Cox regression analysis revealed that FIGO stage is an independent prognostic factor (P = 0.035). Low Ang-1/Ang-2 gene expression ratio had a tendency to be an independent prognostic factor (P = 0.061).

CONCLUSIONS

Angiogenesis occurred by angiopoietin/Tie2 system in concert with VEGF in epithelial ovarian cancer did not affect patients' survival. However, gene expression of Ang-1 and Ang-2 might present a pertinent diagnostic tool to select a high-risk group of patients independent of clinical-pathological parameters and a new insight to understand the biology of epithelial ovarian cancer.

Platelet-derived endothelial cell growth factor as a prognostic factor for radiotherapy outcome in patients with adenocarcinoma of the uterine cervix

OBJECTIVE

The aim of this study was to evaluate the platelet-derived endothelial cell growth factor (PD-ECGF) and VEGF expressions of tumor cells as prognostic factors for radiotherapy outcome in patients with adenocarcinoma of the uterine cervix.

METHODS

In 47 formalin fixed, paraffin-embedded tissues from adenocarcinoma of the uterine cervix which had been treated with radiation (1970-1995), PD-ECGF and VEGF expressions were determined using immunohistochemistry, and the relationships between PD-ECGF or VEGF expressions and local control or survival were assessed.

RESULTS

PD-ECGF and VEGF expressions were successfully detected in the cytoplasm and/or nucleus of adenocarcinoma cells of the uterine cervix. Of the 47 patients, 44.6 (21/47 cases) and 57.4% (27/47 cases) were positive for PD-ECGF and VEGF, respectively. There was no correlation between PD-ECGF or VEGF expressions and age, grade, or histologic subtypes. Stage and high expression of PD-ECGF showed a significant correlation to local control (P = 0.0025, P = 0.0057, respectively) and were significant independent prognostic factors for 5-year survival in multivariate analysis (P = 0.0039, P = 0.0032, respectively).

CONCLUSION

This study demonstrated that PD-ECGF expression was a significant prognostic factor for radiotherapy outcome in patients with adenocarcinoma of the uterine cervix. Preradiation assessment of PD-ECGF expression may be helpful in selecting high-risk patients, providing them with opportunities to receive more sophisticated and individualized treatments.

Effect of p53 gene transfection on vascular endothelial growth factor expression in endometrial cancer cells

It has been reported that tumor suppressor gene p53 regulates vascular endothelial growth factor (VEGF) expression, but the relation between them in endometrial carcinoma remains unclear. We investigated VEGF expression in 11 endometrial carcinoma cell lines and the effect of p53 gene transfection on VEGF expression in the p53-mutated endometrial carcinoma cell line, HEC-50B. Immunoblotting for detecting VEGF, p53, and beta-actin was performed. Wild type p53 gene was transfected using the SuperFect method. The mean VEGF value of 0.8 +/- 0.3 (n = 6) in p53 wild-type group was significantly lower than the 1.6 +/- 0.8 (n = 5) that was found in the p53 mutant group (P < 0.05). Levels of VEGF in the culture medium were measured by enzyme immunoassay (EIA). VEGF levels in the p53 gene-transfected HEC-50B cells and the conditioned medium were decreased at 48 h after p53 gene transfection. VEGF expression was downregulated by p53 in endometrial carcinoma cells.

VEGF expression and its reguration by p53 gene transfection in endometrial carcinoma cells

Vascular endothelial growth factor (VEGF) that activates endothelial cell growth induces angiogenesis, which is indispensable to tumor igenesis and tumor progression. On the other hand, tumor suppressor gene p53 has been considered to regulate VEGF expression, but the detailed relationship between them remains unclear. In this study, we aimed to study VEGF expression in endometrial carcinoma cells and the effect of p53 gene transfection on VEGF expression using p53-mutated endometrial carcinoma cell line, HEC-50B. Immunoblotting for detecting VEGF protein, p53 protein and beta-actin was performed using 11 endometrial carcinoma cell lines. Levels of VEGF in the cultured media were measured by Enzyme immunoassay(EIA). Transfection of wild p53 gene was carried out by SuperFect method in HEC-50B cells, which had mutant p53 gene and did not express p53 protein. The results of immunoblotting were analyzed by NIH image and expressed as values. The results of EIA were expressed as the relative value. The VEGF value was 0.8 +/- 0.3 (n = 6) in p53-wild group, whereas in p53-mutant group it was 1.6 +/- 0.8 (n = 5). VEGF expression was correlated significantly with p53 status (P < 0.05). VEGF levels in p53 gene-transfected cells and the conditioned medium were decreased in 48 hours after p53 gene transfection. VEGF expression was down-regulated by p53 in endometrial carcinoma cells.

A phase I and pharmacokinetic study of capecitabine in combination with epirubicin and cisplatin in patients with inoperable oesophago-gastric adenocarcinoma

BACKGROUND

The purpose of this study was to evaluate the dose-limiting toxicity (DLT) and maximum tolerated dose of capecitabine when used in combination with epirubicin and cisplatin (ECC) in patients with oesophageal or gastric adenocarcinoma. Response rate, progression-free survival (PFS) and overall survival were also determined, and the effect of previous oesophago-gastric surgery or concurrent oesophago-gastric cancer on the absorption and metabolism of capecitabine was evaluated.

PATIENTS AND METHODS

Patients with inoperable oesophago-gastric adenocarcinoma received up to six cycles of epirubicin (50 mg/m(2) i.v., 3-weekly), cisplatin (60 mg/m(2) i.v., 3-weekly) and capecitabine, the latter administered orally in an intermittent schedule (14 days treatment; 7-day rest period) at 3-weekly intervals. Patients were recruited into one of four escalating dose cohorts (500, 825, 1000 and 1250 mg/m(2) bd). Dose escalation occurred after six patients had completed at least one cycle of chemotherapy at the previous dose level, with DLT assessed on the toxicity of the first cycle only. Blood sampling for pharmacokinetic analyses was performed over the first 10 h of day 1 of cycle 1.

RESULTS

Thirty-two patients, median age 63 years (range 32-76 years), ECOG performance status < or =2 with locally advanced (10) or metastatic (22) disease were recruited and were evaluable for toxicity. Two of five patients experienced DLT at 1250 mg/m(2) bd with grade II stomatitis (one patient) and grade III diarrhoea with febrile neutropenia (one patient). Cumulative toxicity for all cycles (n = 140) (worst grade per patient) includes grade IV oesophagitis (one patient), grade III diarrhoea (five), grade IV neutropenia with infection (seven), grade II stomatitis (four) and grade IV thrombocytopenia (one). Of 29 patients with evaluable disease, there was one complete response and six partial responses [24% response rate [95% confidence interval (CI) 10% to 44%]], a median PFS of 22 weeks (95% CI 17-27 weeks) and median overall survival of 34 weeks (95% CI 19-49 weeks). Capecitabine was rapidly absorbed after oral administration, with a t(max) of 1-2 h for capecitabine, DFCR (5'-deoxy-5-fluorocytidine) and DFUR (5'-deoxy-5-fluorouridine). The C(max) and AUC(0-)( infinity ) for capecitabine, DFCR and DFUR were similar to those observed in previous monotherapy studies of capecitabine taken after food.

CONCLUSION

A dose of 1000 mg/m(2) bd of capecitabine is recommended for use on an intermittent schedule in combination with these doses and schedule of epirubicin and cisplatin. This regimen is tolerable and active in oesophago-gastric adenocarcinoma. A randomised phase III comparison with ECF is justified.

Helicobacter pylori infection and expression of the angiogenic factor platelet-derived endothelial cell growth factor by pre-neoplastic gastric mucosal lesions and gastric carcinoma

BACKGROUND

Expression of the angiogenic factor platelet-derived endothelial cell growth factor is induced in some gastric carcinomas. Whether angiogenesis is induced early in the development of gastric pre-neoplastic lesions and whether Helicobacter pylori infection affects platelet-derived endothelial cell growth factor expression is not known.

AIM

To assess whether chronic gastritis, intestinal metaplasia, gastric dysplasia and gastric carcinomas express platelet-derived endothelial cell growth factor and whether Helicobacter pylori infection might affect the expression of platelet-derived endothelial cell growth factor in these lesions.

PATIENTS AND METHODS

Patients with gastric carcinomas, atrophic gastritis with associated intestinal metaplasia, dysplasia and controls without infection or carcinoma were studied.

RESULTS

Platelet-derived endothelial cell growth factor was detected by immunohistochemistry in 9 out 19 gastric carcinomas (45%). Only focal immunostaining was detected in intestinal metaplasia adjacent to dysplasia and in dysplastic cells. Of the tumours, 90% contained platelet-derived endothelial cell growth factor-positive interstitial cells. A significant correlation was found between active Helicobacter pylori infection and a larger number of platelet-derived endothelial cell growth factor-positive interstitial cells in areas of intestinal metaplasia (p<0.05).

CONCLUSION

Helicobacter pylori infection does not influence the expression of platelet-derived endothelial cell growth factor, once gastric cancer has developed. However, Helicobacter pylori infection may increase the extension of expression of platelet-derived endothelial cell growth factor by infiltrating interstitial cells in premalignant lesions, such as intestinal metaplasia, which may help create a favourable environment for tumour development. This may possibly be due to non-specific increase in recruitment of inflammatory cells caused by Helicobacter pylori infection. Further studies, with a larger number of samples, are now needed in order to confirm this finding.

Relationship between the expression of iNOS, VEGF, tumor angiogenesis and gastric cancer

AIM: To investigate the relationship between the expression of inducible nitric oxide synthase (iNOS), vascular endothelial growth factor (VEGF), the microvascular density (MVD) and the pathological features and clinical staging of gastric cancer.

METHODS: Immunohistochemical staining was used for detecting the expression of iNOS and VEGF in 46 resected specimens of gastric carcinoma; the monoclonal antibody against CD34 was used for displaying vascular endothelial cells, and MVD was detected by counting of CD34-positive vascular endothelial cells.

RESULTS: Of 46 resected specimens of gastric carcinoma, the rates of expressions of iNOS and VEGF were 58.70% and 76.09%, respectively, and MVD averaged 55.59 ± 19.39. Judged by the standard TNM criteria, the rate of expression of iNOS in stage IV (84.46%) was higher than those in stage I, II, III (Fish exact probabilities test, P = 0.019, 0.023 and 0.033, respectively); the rates of expression of VEGF in stage III, IV (76.0%, 92.31%, respectively) were higher than those in stage I, II (Fish exact probabilities test, P = 0.031, 0.017, 0.022 and 0.019). MVDs in stage III, IV (64.72 ± 14.96, 67.09 ± 18.29, respectively) were higher than those in stage I, II (t = 2.378, 4.015, 2.503 and 2.450, P < 0.05, P < 0.001, P < 0.001, P < 0.05, respectively). In 37 gastric carcinoma specimens with lymph node metastasis, MVD (68.69 ± 18.07) and the rates of expression of iNOS and VEGF (70.27%, 83.78%, respectively) were higher than those in the specimens with absence of metastasis (t = 2.205, χ² = 6.3587, χ² = 6.2584, P < 0.01, P < 0.05, P < 0.05, respectively). MVD and the expressions of iNOS and VEGF were not correlated to the location, size or grade of tumor, nor with the depth of invasion of tumor; MVDs in the positive iNOS and VEGF specimens (59.88 ± 18.02, 58.39 ± 17.73, respectively) were higher than those in the negative iNOS and VEGF specimens (χ² = 6.3587 and 6.1574, P < 0.05, P < 0.05, respectively); thus the expressions of iNOS and VEGF was correlated to MVD, but the expression of iNOS was not correlated to that of VEGF. In addition, of the 46 surviving patients, the 5-year survival rate of patients with positive iNOS or VEGF tumors was significantly less than that of patients with negative iNOS-or VEGF tumors (χ² = 4.3842 and 5.4073, P < 0.05, P < 0.05, respectively).

CONCLUSION: The expressions of iNOS and VEGF are closely related to tumor angiogenesis, and are involved in the advancement and the lymph node metastasis; thus MVD and the expressions of iNOS and VEGF may serve indexes for evaluating staging of gastric carcinoma and forecasting its risk of metastasis, which will help establish a comprehensive therapeutical measure of post-operative patients and provide a new approach to tumor therapy.

Prognostic significance of ultrasound derived intratumoral peak systolic velocity in epithelial ovarian cancer

OBJECTIVE

To evaluate the prognostic significance of ultrasound derived intratumoral peak systolic velocity in epithelial ovarian cancer.

DESIGN

Color Doppler imaging and pulsed Doppler spectral analysis were used in the investigation of 49 patients with epithelial ovarian cancer (19 serous, 15 mucinous, eight endometrioid, four clear cell and three Brenner cell) immediately before laparotomy. Twenty-two were stage I, six were stage II, 17 were stage III and four were stage IV. Sections of malignant tumors were analyzed for the cellular expression of thymidine phosphorylase and the intratumoral density of microvessels by immunohistochemistry using antibodies to thymidine phosphorylase and factor VIII-related antigen, respectively. Moreover, the apoptotic index was evaluated by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling method. Intratumoral peak systolic velocity was tested for correlation with patients' age at diagnosis, stage of disease, presence of a residual tumor, histological subtype and grade, thymidine phosphorylase expression, apoptotic index, microvessel count and patient survival.

RESULTS

Histological grade (P = 0.025), thymidine phosphorylase expression (P = 0.044), apoptotic index (P = 0.039) and microvessel count (P = 0.014) were all significantly associated with peak systolic velocity. Stage of disease (P = 0.002), presence of residual disease (P = 0.0002) and peak systolic velocity (P = 0.041) were found by univariate Cox regression analysis to be significantly associated with a poor prognosis. Multivariate Cox regression analysis revealed that stage of disease (P = 0.006) and peak systolic velocity (P = 0.008) are independent prognostic factors.

CONCLUSIONS

Intratumoral peak systolic velocity could be a preoperatively pertinent prognostic predictor of survival in patients with epithelial ovarian cancer.

Circulating VEGF levels in the serum of gastric cancer patients: correlation with pathological variables, patient survival, and tumor surgery

OBJECTIVE

To evaluate the clinical usefulness of serum vascular endothelial growth factor (VEGF) levels in gastric cancer patients.

SUMMARY BACKGROUND DATA

Vascular endothelial growth factor plays an important role in the formation of new blood vessels involved in the growth and metastatic spread of solid tumors, but there is limited information regarding the clinical significance of serum VEGF levels in cancer patients.

METHODS

Serum VEGF concentrations were measured by an enzyme linked immunosorbent assay in 61 healthy controls and in 58 gastric cancer patients before surgery, and then again at 7 and 30 days after surgery. The association between preoperative serum VEGF levels, clinicopathological features and patient survival, and their changes following surgery were evaluated.

RESULTS

Serum VEGF levels in gastric cancer patients were significantly higher than those in controls. There was a significant association between serum VEGF levels and disease stage, as well as invasion depth of the tumor and the presence of distant metastases. Serum VEGF levels decreased significantly after radical resection of the primary tumor and increased in patients with unresectable tumors. Multivariate regression analysis showed that serum VEGF level is an independent prognostic factor for survival.

CONCLUSIONS

Serum VEGF levels in gastric patients are significantly higher compared with normal controls and correlate with local tumor extent, disease stage, and the presence of distant metastases. Preoperative serum VEGF concentration decreases significantly after radical resection of the primary tumor and is an independent prognostic factor for patient survival suggesting that determination of serum VEGF levels may be clinically useful.

Towards a biological staging model for operable non-small cell lung cancer

Non-small cell lung cancer is the most common cause of cancer-related death in North America and Europe. Despite improvements in the diagnosis and treatment of the disease the prognosis remains poor, the overall 5-year survival being 4-14%. An increased understanding of the molecular biology of the disease may identify novel targets for drug development. We evaluated epidermal growth factor receptor (EGFR), HER-2/neu, matrix metalloproteinase (MMP)-2, MMP-9, p53 and bcl-2 expression and microvessel density (MVD) in patients who underwent surgery with curative intent in our department between 1991 and 1996. Co-expression of EGFR/MMP-9, MVD and bcl-2 were found to be independent prognostic variables, which allowed prediction of patient outcome independent of surgical stage. Other prognostic factors identified in our series were gender, surgical stage, platelet count, extent of necrosis, the hypoxia marker carbonic anhydrase-9 and beta-catenin. In collaboration with groups in Oxford and Greece, we were also able to establish the angiogenic growth factors vascular endothelial growth factor and platelet-derived endothelial growth factor as prognostic variables. The inter-relationships between these factors are currently being examined in an expanded patient series. Through this work we hope to be able to construct an integrated biological prognostic model which can be tested in prospective studies. This work has identified several potential targets for novel therapeutic agents currently in development.

Impact of thymidine phosphorylase surexpression on fluoropyrimidine activity and on tumour angiogenesis

Tumoral thymidine phosphorylase (TP) appears to play a dual role by being involved in neoangiogenesis and by activating 5FU prodrugs at the tumoral target site. The aim of the study was to investigate more thoroughly these potential physiological and pharmacological roles of TP. A rat carcinoma cell line (PROb) was transfected with TP/PD-ECGF in order to study the effect of the overexpression of this enzyme (1) on the sensitivity of cells to 5'DFUR and 5FU in vitro and (2) on tumour growth in vivo by using a syngenic tumour model in the BDIX rat (hepatic tumours, sub-cutaneous tumours). Cytotoxic effects of 5'DFUR, and to a lesser extent those of 5FU, were enhanced in TP clones as compared to control cells: there was a highly significant correlation between TP activity and in vitro sensitivity to 5'DFUR (r2= 0.91, P = 0.0002, n = 8) and, to a lesser extent, to 5FU (r2= 0.49, P = 0.053, n = 8). The impact of TP transfection on tumour growth was relatively modest and concerned only the initial stages of tumour expansion. Staining of TP tumours for endothelial (factor VIII) cells was always higher than controls. The staining ratio (TP/controls) tended to be reduced as tumours increased in size. The stability of TP expression was checked both in vitro (TP activity measurement) and in vivo (RT-PCR determinations) and there was no loss of TP expression over time which could be advanced to explain the progressive weakening of the impact of TP overexpression on both tumour growth and neoangiogenesis.

Angiogenic effect of thymidine phosphorylase on macrophages in glioblastoma multiforme

OBJECT

Thymidine phosphorylase (TP) and vascular endothelial growth factor (VEGF) are known angiogenic factors; however, there are few reports in which the relationship between these two factors is addressed. The authors compared expression patterns of TP and VEGF and investigated their role in the angiogenesis of glioblastoma multiforme (GBM).

METHODS

Surgical specimens from 41 cases of GBM were immunohistochemically stained for TP, VEGF, CD68 (a macrophage marker), and CD31 (an endothelial cell marker). Both TP labeling indices and VEGF immunoreactivity displayed significant correlations with vascular density. Although VEGF was diffusely distributed in the tumor, TP was strongly expressed around blood vessels and in vascular proliferation. Double labeling for TP and CD68 in 10 cases indicated that cells that reacted strongly positive for TP were almost always macrophages, and only small numbers of CD68-negative cells weakly expressed TP. The TP messenger (m)RNA expression was investigated using reverse transcription-polymerase chain reaction in six GBMs. All six specimens expressed TP mRNA. In addition, TP mRNA was detected in two of three groups of cultured GBM cells derived from surgical specimens. Macrophages, the production of which was induced from two volunteers' peripheral blood monocytes by applying macrophage colony-stimulating factor, also expressed TP mRNA. The glioma cell lines U251MG and U87MG, which barely express TP mRNA under normal conditions, expressed TP mRNA in response to interferon-beta stimulation or while in an anoxic condition.

CONCLUSIONS

Although it is feasible that GBM cells can express TP depending on their growing conditions, the majority of TP-expressing cells present in GBMs appear to be infiltrating macrophages. Coexistence of VEGF and TP may indicate a synergistic upregulation for angiogenesis because VEGF exerts a chemotactic activity on macrophages that express TP.

Angiogenesis and apoptosis-related protein (p53, bcl-2, and bax) expression versus response of gastric adenocarcinomas to paclitaxel and carboplatin chemotherapy

The role of angiogenesis and apoptosis-related proteins in defining response to chemotherapy is poorly understood. We examined the microvessel density (MVD) and the expression of p53, bcl-2, and bax proteins in a series of 28 locally advanced gastric adenocarcinomas, treated with paclitaxel and carboplatin. A strong cytoplasmic reactivity in more than 10% of cancer cells was recorded in 25% of cases for p53 protein, and in 14% and 64% of cases for bcl-2 and bax proteins, respectively. Microvessel density was assigned in three categories: low (<35), medium (35-60), and high (>60). Tumors of medium MVD showed a significantly higher response rate compared with those of high or low MVD (p = 0.01 and 0.001, respectively), and prognosis was significantly better in this group of patients with medium MVD tumors (p < 0.02). Loss of bax protein expression was somewhat more frequent in tumors resistant to chemotherapy, but this difference was not of statistical significance. Nuclear p53 reactivity was associated with higher MVD (p = 0.02). The expression of p53 and bcl-2 did not influence the outcome of treatment. The present study suggests that although apoptosis-related proteins may have a role in defining response to taxanes, parameters related to tumors' vasculature, such as drug availability or angiogenic tissue regeneration, may be equally important.

Expression of CD34 in gastric cancer and its correlation with histology, stage, proliferation activity, p53 expression and apoptotic index

The formation of new blood vessels is essential for tumor growth and progression. Until today there are only few studies of the immunohistochemical assessment of angiogenesis in gastric cancer by the evaluation of the expression of CD34 antigen. The aim of this study was to analyze the relationship between microvessel density (MVD) expressed as the mean count of CD34 immunostained vessels and clinicopathologic features of gastric tumors (the histological type according to the Lauren classification, tumor grade G; presence of lymph node metastases N; depth of tumor invasion; stage of disease (UICC-AJCC 1988 1992), p53 expression, tumor cell proliferative activity described as the Ki67 labelling index and apoptotic index of tumor cells TUNEL method). We assessed formalin-fixed, paraffin-embedded tissue samples obtained during potentially radical gastrectomy from 58 patients with primary gastric adenocarcinoma. The representative tissue blocks from each tumor were used for the immunohistochemical assay and examined by two pathologists independently. MVD was counted in five tumor areas of the most intensive neovascularization (x 200 field by light microscopy) and the mean counts were recorded. The mean MVD (CD34 expression value+/-SD) in this study was 43,15+/-19,8 per x 200 field. The study demonstrated the statistically significant correlation between MVD and two main histological parameters: tumor grading (p < 0.001) and tumor histological type according to Lauren s classification (p<0.05). In well and moderately differentiated tumors (G1/2) MVD was significantly lower in comparison to the group of poorly differentiated cancer G3 (mean value: 31,62 vs. 49,89). MVD was higher in diffuse type of gastric cancer comparing to intestinal type (50.05+/-19,03 vs. 39.17+/-20,09). However, the authors failed to find a significant correlation between MVD and other investigated histopathological features in malignant gastric tumors. The close relationship between CD34 immunostaining, gastric cancer tumor vascularity and main histological parameters was shown in this study. It can be stated that analysis of expression of angiogenesis in gastric cancer may be helpful for better estimation of hematogenous recurrence and the selection of the group of patients for adjuvant antiangiogenic treatment.

Prognostic significance of expression of thymidine phosphorylase and vascular endothelial growth factor in human gastric carcinoma

BACKGROUND AND OBJECTIVES

Both thymidine phosphorylase (dThdPase) and vascular endothelial growth factor (VEGF) are well-characterized inducers of angiogenesis. The purpose of this study was to examine the expression of these antigens and their prognostic significance in gastric carcinoma.

METHODS

Medical records of 102 patients with stage II tumor were retrospectively reviewed. Primary tumors were studied by immunohistochemical staining for dThdPase and VEGF.

RESULTS

Positive dThdPase expression was observed in 52 (51%) tumors and positive VEGF expression in 53 (52%) tumors. There was a significant correlation between the positive expression of VEGF and lymphatic invasion. The patients with dThdPase-positive carcinoma showed a significantly worse prognosis than those with dThdPase-negative carcinoma in stage II. Moreover, the frequency of hepatic recurrence was significantly higher in the patients with dThdPase-positive and VEGF-positive tumors than in those with dThdPase-negative and VEGF-negative tumors.

CONCLUSIONS

Combination analysis of dThdPase and VEGF expression in gastric carcinoma appears to be well-characterized inductors of prognosis and metastasis.

Tumour vasculature as a target for anticancer therapy

The development of a blood supply is crucial to the growth and metastasis of cancer. The factors involved in this are complex, however tumour hypoxia and macrophage infiltration are responsible for the synthesis of pro-angiogenic cytokines such as vascular endothelial growth factor (VEGF) and the fibroblast growth factors. These factors stimulate proliferation of vascular endothelial cells, the synthesis of proteases such as urokinase type plasminogen activator (uPA) and the matrix metalloproteases, which result in digestion of the extracellular matrix and allow endothelial cell invasion. Endothelial cell motility is promoted by binding of extracellular matrix proteins such as vitronectin and fibronectin to integrins expressed on the plasma membrane of endothelial cells. Interfering with any of these steps may inhibit the process of angiogenesis and drugs aimed at modulation of angiogenesis are currently undergoing evaluation in early clinical studies. This paper reviews our current understanding of angiogenesis and how it may be used as a target for the treatment of cancer.

Prognostic value of vascular endothelial growth factor expression in colorectal cancer patients

Solid tumours require neovascularisation for growth and metastasis. Vascular endothelial growth factor (VEGF) has been shown to be an important regulator of tumour angiogenesis. To examine the relevance of VEGF in the neoplastic transformation of human colon, we analysed protein expression in a total 30 polyps and 145 colorectal carcinomas by immunohistochemistry. All adenoma specimens, regardless of histological differentiation, and normal colonic mucosa did not express VEGF. Amongst 90 patients with non-metastatic colorectal cancer, VEGF expression was observed in 43 (48%) cases, whilst 29 of the 55 patients (53%) with metastases expressed the angiogenic factor. Both the proportion and intensity of VEGF expression were positively associated with the progression of colon carcinogenesis. Tumours with the highest VEGF expression tended to correlate with patients' survival, although VEGF expression did not emerge as an independent risk factor in a multivariate analysis. After exclusion of the patients with distant metastases, both univariate and multivariate analysis did not indicate any prognostic value for the tissues with the highest VEGF expression. Our results suggest that VEGF may play a role in the progression of colon cancer, although evaluation of this angiogenic phenotype did not provide additional prognostic information compared with that obtained from Dukes' staging of the tumours.

Vascular endothelial growth factor, platelet-derived endothelial cell growth factor and angiogenesis in non-small-cell lung cancer

High microvessel density, an indirect measure of angiogenesis, has been shown to correlate with increased tumour size, lymph node involvement and poor prognosis in non-small-cell lung cancer (NSCLC). Tumour cell vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF) expression correlate with angiogenesis and a poor outcome in this disease. In a retrospective study VEGF and PD-ECGF expression and microvessel density were evaluated immunohistochemically in surgically resected specimens (T1-3, N0-2) from 223 patients with operable NSCLC using the VG1, P-GF.44C and JC70 monoclonal antibodies respectively. High VEGF immunoreactivity was seen in 104 (46.6%) and PD-ECGF in 72 (32.3%) cases and both were associated with high vascular grade tumours (P= 0.009 and P= 0.05 respectively). Linear regression analysis revealed a weak positive correlation between VEGF and PD-ECGF expression in cancer cells (r= 0.21; P = 0.002). Co-expression of VEGF and PD-ECGF was not associated with a higher microvessel density than VEGF or PD-ECGF only expressing tumours. Furthermore a proportion of high vascular grade tumours expressed neither growth factor. Univariate analysis revealed tumour size, nodal status, microvessel density and VEGF and PD-ECGF expression as significant prognostic factors. Tumour size (P < 0.02) and microvessel density (P < 0.04) remained significant on multivariate analysis. In conclusion, VEGF and PD-ECGF are important angiogenic growth factors and have prognostic significance in NSCLC. Furthermore the study underlines the prognostic significance of microvessel density in operable NSCLC.

Expression of thymidine phosphorylase in epithelial ovarian cancer: correlation with angiogenesis, apoptosis, and ultrasound-derived peak systolic velocity

OBJECTIVE

The objective of this study was to determine whether the expression of thymidine phosphorylase (TP) by epithelial ovarian cancer cells correlates with the density of microvessels within the tumor, apoptotic index (AI) within the tumor cells, and ultrasound-derived blood flow.

METHODS

Color Doppler imaging and pulsed Doppler spectral analysis ultrasonography were used to scan 44 patients with an overt ovarian mass immediately before laparotomy. Sections of malignant tumors were analyzed for the cellular expression of TP and the intratumoral density of microvessels by immunohistochemistry using antibodies to TP and factor-VIII-related antigen, respectively. Moreover, AI was evaluated by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling methods.

RESULTS

Forty-four epithelial ovarian cancers were studied (6 low malignant potential, 15 serous cystadenocarcinoma, 9 mucinous cystadenocarcinoma, 8 endometrioid adenocarcinoma, 4 clear cell carcinoma, and 2 malignant Brenner tumors); 19 were Stage I, 6 Stage II, 15 Stage III, and 4 Stage IV. Fourteen tumors (32%) were classified as being TP positive. The proportion of Stage I tumors that was TP positive (16%) was significantly lower (P = 0.022) that the corresponding value for Stages II-IV (44%), although the values for microvessel count, AI, and peak systolic velocity (PSV) were similar. AI was significantly lower in TP-positive tumors than in TP-negative tumors (P = 0.015). The PSV was significantly higher in TP-positive tumors (P = 0.02). There was a significant correlation between the microvessel count and the PSV (r = 0.34, P = 0.024). Moreover, AI was significantly inversely related to the PSV (r = 0. 35, P = 0.023). The PSV in a subgroup with a high microvessel count and low AI was significantly higher than that in a subgroup with a low microvessel count and high AI (P = 0.0006). These findings significantly associated with TP expression (P = 0.024).

CONCLUSIONS

The intratumoral PSV, as determined by color Doppler imaging and spectral analysis, might reflect the coordination of angiogenesis and apoptosis associated with TP expression in epithelial ovarian cancer.

Significance of thymidine phosphorylase/platelet-derived endothelial cell growth factor in carcinoma of the papilla of Vater

The expression of thymidine phosphorylase (TP) in carcinoma of the papilla of Vater was studied to clarify its significance in tumor progression and in determining prognosis. Fifty-nine cases of surgically resected carcinoma of the papilla of Vater were studied. Immunohistochemical staining was performed to evaluate the expression of TP, microvessel count and p53 overexpression. TP expression was demonstrated in tumor cells in 62.7% (37/59) of the cases. A higher frequency of regional lymph node metastasis was found in TP-positive tumors than in TP-negative tumors (P = 0.006). TP-positive tumors were more advanced than TP-negative tumors with regard to clinical stage (P = 0.035). TP-positive tumors had significantly higher microvessel density (27.6 +/- 10.1) than TP-negative tumors (20.4 +/- 10.0, P = 0.01). Moreover, TP expression was significantly correlated with a poor prognosis (P = 0. 02). These suggest that in carcinoma of the papilla of Vater, TP production by tumor cells is correlated with tumor progression through its regulatory effect on neovascularization.

Thymidine phosphorylase, 2-deoxy-D-ribose and angiogenesis

Angiogenesis is the term used to describe the formation of new blood vessels from the existing vasculature. In order to attract new vessels, a tissue must release an endothelial-cell chemoattractant. 2-Deoxy-D-ribose is produced in vivo by the catalytic action of thymidine phosphorylase (TP) on thymidine and has recently been identified as an endothelial-cell chemoattractant and angiogenesis-inducing factor. TP, previously known only for its role in nucleotide salvage, is now known to be angiogenic. TP expression is elevated in many solid tumours and in chronically inflamed tissues, both known areas of active angiogenesis. There is evidence that TP is also involved in physiological angiogenesis such as endometrial angiogenesis during the menstrual cycle. The majority of known endothelial-cell chemoattractants are polypeptides that bind to endothelial-cell-surface receptors. In contrast, 2-deoxy-D-ribose appears to lack a cell-surface receptor. Glucose is another sugar that acts as an endothelial-cell chemoattractant. The migratory activity of glucose is blocked by ouabain. It is possible that 2-deoxy-D-ribose and glucose stimulate endothelial-cell migration via a similar mechanistic pathway.