Expression of vascular endothelial growth factor and its receptor Flk-1 in human neuroblastoma using in situ hybridization.

Although angiogenic factors may play an important role in the biology of neuroblastoma, which frequently spreads hematogenously, the mechanism remains unclear. The authors studied tumor progression and invasion from the perspective of angiogenesis and sought to understand the features of this type of tumor. Thirty-one specimens were resected from patients with neuroblastoma and the expression of vascular endothelial growth factor (VEGF), and its receptor (Flk-1) was examined using immunohistochemistry. The authors looked for correlations among the expressions of VEGF and its receptor with various clinicopathologic factors. In addition, they examined the expression and location of VEGF and Flk-1 mRNA in 10 primary neuroblastoma using in situ hybridization. Both in situ hybridization and immunohistochemistry showed the presence of VEGF expression within the neuroblastoma cells. We found VEGF mRNA in neuroblastoma cells but not vascular endothelial cells according to in situ hybridization. Further, Flk-1 mRNA was present both in neuroblastoma cells and vascular endothelial cells. The level of VEGF expression was higher in unfavorable histology, using the criteria of Shimada, than in favorable histology. The authors suggest that paracrine and autocrine systems are involved in the angiogenesis of neuroblastoma, and the expression of VEGF correlates with the prognosis in neuroblastoma.

Fukuzawa M ，Sugiura H ，Koshinaga T ，Ikeda T ，Hagiwara N ，Sawada T ... -  《-》

Gene expression of vascular endothelial growth factor and its receptors and angiogenesis in bronchial asthma.

Angiogenesis is a feature of airway remodeling in bronchial asthma. The mechanism responsible for this angiogenesis is unknown. Vascular endothelial growth factor (VEGF) is a potent inducer of endothelial cells, which may contribute to chronic inflammation and angiogenesis. We sought to investigate the molecular mechanisms underlying increased vascularity, and we examined the mRNA expression of VEGF and its receptors (flt-1 and flk-1) within bronchial biopsy specimens from asthmatic patients and normal control subjects. Endobronchial biopsy specimens were examined immunocytochemically by staining with anti-type IV collagen mAb to evaluate vessel density by using computer-assisted image analysis. Specimens were also analyzed for the presence of the mRNAs of VEGF and its receptors with in situ hybridization. The extent of airway vascularity was increased in asthmatic subjects compared with that in control subjects (P <.01). Asthmatic subjects exhibited a greater expression of VEGF, flt-1, and flk-1 mRNA(+) cells in the airway mucosa compared with that in control subjects (P <.001 for each comparison). The degree of vascularity was associated with the number of VEGF, flt-1, and flk-1 mRNA(+) cells. Numbers of cells expressing VEGF mRNA inversely correlated with airway caliber (r = -0.83, P <.01) and airway hyperresponsiveness (r = -0.97, P <.001). Colocalization studies showed that macrophages, eosinophils, and CD34(+) cells were the major sources of VEGF; CD34(+) cells, macrophages, and T cells expressed both flt-1 and flk-1. These findings provide evidence that VEGF may play an important role in angiogenesis and subsequent airway remodeling in bronchial asthma.

Hoshino M ，Nakamura Y ，Hamid QA 《JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY》

Expression of vascular endothelial growth factor (VEGF) and its receptors (Flt-1 and Flk-1) in esophageal squamous cell carcinoma.

Kato H ，Yoshikawa M ，Miyazaki T ，Nakajima M ，Fukai Y ，Masuda N ，Fukuchi M ，Manda R ，Tsukada K ，Kuwano H ... -  《ANTICANCER RESEARCH》

Expression of vascular permeability factor (vascular endothelial growth factor) and its receptors in endometrial carcinoma.

Solid tumors, including endometrial carcinomas, must induce a vascular stroma to grow beyond a minimal size. The mechanisms responsible for angiogenesis in endometrial carcinoma, however, are not well defined. Vascular permeability factor (VPF), also known as vascular endothelial growth factor (VEGF), is a multifunctional cytokine that is an important regulator of tumor angiogenesis. We evaluated VPF/VEGF mRNA and protein expression, as well as VPF/VEGF receptor mRNA expression, in endometrial carcinoma. Fourteen examples of endometrial carcinoma were evaluated by in situ hybridization; in 7 cases, benign atrophic endometrium from the same patient was also examined. Histologic sections were subjected to in situ hybridization using 35S-labeled riboprobes specific for VPF/VEGF and, in a subset of cases, riboprobes specific for the VPF/VEGF receptors flt-1 and KDR. In addition, ten examples of endometrial carcinoma were evaluated for VPE/VEGF protein expression by immunohistochemistry. All 14 examples of endometrial carcinoma studied by in situ hybridization exhibited focal strong VPF/VEGF mRNA expression by tumor cells. In addition, the endothelial cells of surrounding microvessels strongly expressed flt-1 and KDR mRNAs in all ten cases examined. In contrast, no strong expression of VPF/VEGF, flt-1, or KDR mRNA was observed in the seven examples of benign atrophic endometrium studied. All ten cases of endometrial carcinoma studied by immunohistochemistry exhibited strong VPF/VEGF protein expression by tumor cells. These observations suggest that VPF/VEGF is an important angiogenic factor in endometrial carcinoma.

Guidi AJ ，Abu-Jawdeh G ，Tognazzi K ，Dvorak HF ，Brown LF ... -  《CANCER》

VEGF, flt-1, and KDR/flk-1 as prognostic indicators in endometrial carcinoma.

Tumor angiogenesis is a highly regulated process under the influence of the host microenvironment and mediators. Studies of breast cancer and, more recently, ovarian and cervical cancer, demonstrate that neovascularization correlates with the likelihood of metastasis and recurrence. Vascular endothelial growth factor (VEGF), an important regulator of tumor angiogenesis in the endometrium, flt-1, and KDR/flk-1 are good markers of vascular proliferation. Being that angiogenesis is a precursor to the development of progressive disease, we hypothesize that quantifying VEGF, flt-1, and KDR/flk-1 expression in uterine malignancies is a superior predictor of metastatic potential and survival than is FIGO grade of tumor, depth of invasion, and histology. The histologic slides of 47 patients with uterine malignancies (35 adenocarcinomas, 6 papillary serous, and 6 carcinosarcomas) were reviewed. The paraffin blocks from the primary tumor were obtained. Immunohistochemistry staining was performed for VEGF, flt-1, and KDR/flk-1. Microvessel density, used to analyze VEGF and receptor concentrations, was determined by two independent investigators, who were blinded to the patients clinical status. The impact of VEGF, flt-1, and KDR/flk-1 as well as stage, grade, depth of invasion, and nodal status on the incidence of metastases, recurrence, and survival was determined using logistic regression analysis and product limit life system survival analysis, respectively. Results indicated that when evaluating all three histologic types, only stage and grade of tumor were found to impact upon the incidence of recurrence and survival. When patients with carcinosarcoma and papillary serous adenocarcinoma were excluded from the analysis, once again only stage and grade of tumor were significant prognostic indicators of recurrence and survival. Only grade of tumor and depth of uterine invasion were significant predictors of a tumor's metastatic potential. VEGF, flt-1, and KDR/flk-1 proved to be of little significance in predicting metastases, recurrence, and survival. Patients with advanced disease in all three histologic subtypes often had low VEGF and receptor positivity. In this study, VEGF, flt-1, and KDR/flk-1 receptor concentrations did not correlate with the incidence of metastases, recurrence, and survival.

Fine BA ，Valente PT ，Feinstein GI ，Dey T ... -  《GYNECOLOGIC ONCOLOGY》